cssi/SciSciGPT-SciSciNet huggingface dataset:
Dynamics of the reaction of O− with D2 at low collision energies: reagent rotational energy effects

The effects of reagent rotational excitation on the dynamics of the O−+D2 particle transfer reaction are investigated in a crossed molecular beam experiment. Vibrational-state-resolved angular distributions are measured at collision energies of 0.22, 0.25, and 0.37 eV as a function of the rotational temperature of the D2 reactant gas, which ranges between 58 and 425 K. When the rotational temperature of the D2 is lowered, the angular distributions become more strongly backward scattered with a tighter, more intense peak at 180°. In addition, the relative amounts of forward and sideways scattering are decreased. We interpret these product angular distributions as reflecting specific geometries required for passage through the critical transition state region of the potential energy surface where the particle transfer and electron detachment channels compete. Reagent rotational motion correlates to motion in the transition state that is selectively coupled to electron detachment. The more rotational energy present in the reagents, the smaller the probability that the complex remains linear and produces backward-scattered OD−. The product vibrational-state distributions change by only a few percentage points with the variation in rotational energy. While the small difference in the amount of rotational energy present in this system strongly influences the mechanism of particle transfer, it may not significantly alter the number of trajectories leading to that channel. The dynamics of this system are discussed in terms of a local complex potential describing nuclear motion in the critical region of the potential surface.
Phonological processing in human auditory cortical fields

We used population-based cortical-surface analysis of functional magnetic imaging (fMRI) data to characterize the processing of consonant-vowel-consonant syllables (CVCs) and spectrally-matched amplitude-modulated noise bursts (AMNBs) in human auditory cortex as subjects attended to auditory or visual stimuli in an intermodal selective attention paradigm. Average auditory cortical field (ACF) locations were defined using tonotopic mapping in a previous study. Activations in auditory cortex were defined by two stimulus-preference gradients: (1) Medial belt ACFs preferred AMNBs and lateral belt and parabelt fields preferred CVCs. This preference extended into core ACFs with medial regions of primary auditory cortex (A1) and rostral field (R) preferring AMNBs and lateral regions preferring CVCs. (2) Anterior ACFs showed smaller activations but more clearly defined stimulus preferences than did posterior ACFs. Stimulus preference gradients were unaffected by auditory attention suggesting that different ACFs are specialized for the automatic processing of different spectrotemporal sound features.
A never ending race for new and improved fluorescent proteins

Bioluminescent and fluorescent proteins are now used as tools for research in all organisms. There has been massive progress over the past 15 years in creating a palette of fluorescent proteins with a wide spectrum of specific properties. One of the big challenges is to decide which variant may be best for a certain application. A recent article by Mann et al. in BMC Biotechnology describes a new orange fluorescent protein in plants.
Efficacy of chemical sterilants/disinfectants: is there a light at the end of the tunnel?

Chemical sterilants/disinfectants are used to sterilize or disinfect instruments that cannot tolerate autoclave or gas sterilization. The Environmental Protection Agency (EPA) registers and approves these products for use. Registration is based on EPA approval of data supplied by each manufacturer purporting to prove the efficacy of the product. As described in three previous articles by this author, these claims of efficacy are in question.1-3 Prior to 1982, the EPA conducted limited testing of sterilants, and up to 30% of products failed these verification tests. Since 1982, no tests on manufacturers' claims have been performed by the EPA. Since 1982 and before, independent labs have disputed some of the claims, and the reported inconsistencies in performance have greatly worried infection control personnel. As a result, hearings were conducted by congressional committees, and the conclusions have been reported by the United States General Accounting Office.4 That report states that the "EPA does not know whether disinfectants kill the germs claimed on product labels, and the extent to which ineffective disinfectants are marketed (with EPA registration) is unknown.... Evidence exists that some registrants have submitted to the EPA efficacy test data indicating that their disinfectants work, but have withheld other test data indicating that these disinfectants do not work as claimed."
A modified implicit Monte Carlo method for time-dependent radiative transfer with adaptive material coupling

In this paper we develop a robust implicit Monte Carlo (IMC) algorithm based on more accurately updating the linearized equilibrium radiation energy density. The method does not introduce oscillations in the solution and has the same limit as @Dt->~ as the standard Fleck and Cummings IMC method. Moreover, the approach we introduce can be trivially added to current implementations of IMC by changing the definition of the Fleck factor. Using this new method we develop an adaptive scheme that uses either standard IMC or the modified method basing the adaptation on a zero-dimensional problem solved in each cell. Numerical results demonstrate that the new method can avoid the nonphysical overheating that occurs in standard IMC when the time step is large. The method also leads to decreased noise in the material temperature at the cost of a potential increase in the radiation temperature noise.
CdZnTe strip detector for arcsecond imaging and spectroscopy

A CdZnTe strip detector array with capabilities for arc second imaging and spectroscopy is being developed for a space flight gamma-ray burst instrument. Two dimensional strip detectors with 100 micrometers pitch have been fabricated and wire bonded to readout electronics to demonstrate the ability to localize 22 to 122 keV photons to less than 100 micrometers. In addition, good spectral resolution has been achieved. The uniformity of response and relative efficiency of the strip detector will be discussed. Results form electrical characterization which include strip leakage current and strip capacitance will be presented.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Hypoxia disrupts proteostasis in Caenorhabditis elegans

Oxygen is fundamentally important for cell metabolism, and as a consequence, O2 deprivation (hypoxia) can impair many essential physiological processes. Here, we show that an active response to hypoxia disrupts cellular proteostasis – the coordination of protein synthesis, quality control, and degradation that maintains the functionality of the proteome. We have discovered that specific hypoxic conditions enhance the aggregation and toxicity of aggregation-prone proteins that are associated with neurodegenerative diseases. Our data indicate this is an active response to hypoxia, rather than a passive consequence of energy limitation. This response to hypoxia is partially antagonized by the conserved hypoxia-inducible transcription factor, hif-1. We further demonstrate that exposure to hydrogen sulfide (H2S) protects animals from hypoxia-induced disruption of proteostasis. H2S has been shown to protect against hypoxic damage in mammals and extends lifespan in nematodes. Remarkably, our data also show that H2S can reverse detrimental effects of hypoxia on proteostasis. Our data indicate that the protective effects of H2S in hypoxia are mechanistically distinct from the effect of H2S to increase lifespan and thermotolerance, suggesting that control of proteostasis and aging can be dissociated. Together, our studies reveal a novel effect of the hypoxia response in animals and provide a foundation to understand how the integrated proteostasis network is integrated with this stress response pathway.
Test of Cairns-Smith’s ‘crystals-as-genes’ hypothesis

One aspect of the multifaceted proposal by A. G. Cairns-Smith, that imperfect crystals have the capacity to act as primitive genes by transferring the disposition of their imperfections from one crystal to another, is investigated. Rather than examining clay minerals, the most likely crystalline genes in the theories of Cairns-Smith, an experiment was designed in a model crystalline system unrelated to the composition of the prebiotic earth but suited to a well-defined test. Plates of potassium hydrogen phthalate riddled with dislocations were studied in order to ascertain whether, according to Cairns-Smith, parallel screw dislocations could serve as an information store with cores akin to punches in an old computer card. Evidence of screw dislocations was obtained from their associated growth hillocks through differential interference contrast microscopy, atomic force microscopy, and luminescence labeling of hillocks in conjunction with confocal laser scanning microscopy. The dispositions of growth active hillocks were quantified by fractal analysis. ‘Mother’ crystals were cleaved and inheritance was evaluated by the corresponding patterns of luminescence developed in their ‘daughters’ after continued growth in the presence of fluorophores. Luminescence microscopy proves to be a versatile tool for studying the dynamics of growth active hillocks. In the aggregate, this work speaks to the need for molecular mechanisms of dislocation nucleation.
The Long and Short of Strategic Planning

ROI forces a corporation to measure its performance based on a short‐term horizon. What is needed is a way to blend both short‐term and long‐term plans to achieve corporate objectives.
Network visualization system for computational chemistry.

Network Visualization System for Computational Chemistry (NVSCC) is a molecular graphics program designed for the visualization of molecular assemblies. NVSCC accepts the output files from the most popular ab initio quantum chemical programs, GAUSSIAN and GAMESS, and provides visualization of molecular structures based on atomic coordinates. The main differences between NVSCC and other programs are: Network support due to built-in FTP and telnet clients, which allows for the processing of output from and the sending of input to different computer systems and operating systems. The possibility of working with output files in real time mode. The possibility of animation from an output file during all steps of optimization. The quick processing of huge volumes of data. The development of custom interfaces.
Diffusion of hydrogen and deuterium in ZrVFe

Abstract We have examined the desorption and pumping behavior of a ZrVFe alloy bulk getter. From these data, the diffusivity was calculated to be D H = exp [13.6(0.9) − 18,700 (600)/T] cm 2 s −1 for hydrogen and D D = exp [8.7(2.1) − 14,600(1400)/T] cm 2 s −1 for deuterium. Using this value of D H , the regime where the hydrogen pumping speed becomes pressure dependent was calculated.
Comparison of ice cloud properties simulated by the Community Atmosphere Model (CAM5) with in-situ observations

Abstract. Detailed measurements of ice crystals in cirrus clouds were used to compare with results from the Community Atmospheric Model Version 5 (CAM5) global climate model. The observations are from two different field campaigns with contrasting conditions: Atmospheric Radiation Measurements Spring Cloud Intensive Operational Period in 2000 (ARM-IOP), which was characterized primarily by midlatitude frontal clouds and cirrus, and Tropical Composition, Cloud and Climate Coupling (TC4), which was dominated by anvil cirrus. Results show that the model typically overestimates the slope parameter of the exponential size distributions of cloud ice and snow, while the variation with temperature (height) is comparable. The model also overestimates the ice/snow number concentration (0th moment of the size distribution) and underestimates higher moments (2nd through 5th), but compares well with observations for the 1st moment. Overall the model shows better agreement with observations for TC4 than for ARM-IOP in regards to the moments. The mass-weighted terminal fall speed is lower in the model compared to observations for both ARM-IOP and TC4, which is partly due to the overestimation of the size distribution slope parameter. Sensitivity tests with modification of the threshold size for cloud ice to snow autoconversion (Dcs) do not show noticeable improvement in modeled moments, slope parameter and mass weighed fall speed compared to observations. Further, there is considerable sensitivity of the cloud radiative forcing to Dcs, consistent with previous studies, but no value of Dcs improves modeled cloud radiative forcing compared to measurements. Since the autoconversion of cloud ice to snow using the threshold size Dcs has little physical basis, future improvement to combine cloud ice and snow into a single category, eliminating the need for autoconversion, is suggested.
Perspectives on communication issues among transplant and procurement professionals, transplant recipients, and donor families

Communication among professionals, donor families, and transplant recipients is a controversial topic. Traditionally, transplant and procurement professionals have made the decision about the type and frequency of information that a donor family and transplant recipient receive regarding one another, and relationships that might develop as a result. Information obtained through questionnaires demonstrated inconsistency in addressing donor family and transplant recipient needs for initial and follow-up information and communication-not only between clinical transplant and procurement donation coordinators, but within organizations involved in the care and support of these people. This wide variance regarding communication among all disciplines demonstrated a need for standardization of practice guidelines. Guidelines are being developed through collaboration of the major organizations involved in the care of donor families and transplant recipients to standardize communication practices throughout the United States.
Clinical interventions for severe mental illness and co-occurring substance use disorder.

In order to more effectively treat substance use disorders in persons with severe mental illness, integrated treatment models have been developed for these ‘co-occurring disorders.’ The nature of clinical services provided in these programs is described in this article, with brief attention to research on these programs. Clinical services are generally guided by a stage model of change, in which the client's motivation to change (or stage of treatment: engagement, persuasion, active treatment, relapse prevention) informs the optimal selection of appropriate interventions. Psychotherapeutic services for co-occurring disorders include a range of individual (motivational interviewing, cognitive-behavioral counseling), group (stage-wise groups, social skills training, self-help), and family (single family, multifamily formats) interventions. Supplementary interventions are also commonly provided, including psychopharmacological, residential, coerced and involuntary, and vocational rehabilitation. Access to a range of different interventions for co-occurring disorders may improve the ability of clinicians to engage and tailor treatment to meet clients' unique needs. The research base supporting integrated treatment for co-occurring disorders is limited at this time owing to the small number of methodologically rigorous studies from which to draw conclusions. Nevertheless, the available evidence suggests that integrated treatment programs improve outcomes compared with nonintegrated approaches, and that more research is needed to evaluate the benefits of these programs.
Rapid hydrogen sulfide consumption by Tetrahymena pyriformis and its implications for the origin of mitochondria

Although sulfide is typically regarded as toxic to eukaryotic cells, it is avidly consumed by Tetrahymena pyriformis. That was observed only when the sulfide concentration was kept below 1 microM. Previously concentrations that were too high had been tested. A new device (Sulfidostat) was used to measure sulfide consumption in steady-state concentrations as low as 10(-12)M. The technique was validated non-biologically by slowly injecting AgNO(3) into buffer and using Ag(2)S precipitation to mimic sulfide consumption, confirming that rates of sulfide consumption could be measured independently of sulfide concentrations. With T. pyriformis, sulfide consumption was 0.25 micromol (gprotein)(-1)s(-1) in 0.5 microM sulfide. Sulfide consumption required O(2) and was inhibited by HCN or by too much sulfide. When cells were separated into fractions, sulfide consumption occurred in the particulate (mitochondrial) fraction. Unexpectedly, the soluble cytosolic fraction slowly produced sulfide even when aerated. The observations are consistent with the conjecture that mitochondria evolved from sulfidotrophic symbionts in a sulfidogenic host cell.
Three-Dimensional Microscopy: Image Processing For High Resolution Subcellular Imaging

Recent technological advances now make it practical to record three-dimensional data from biological specimens using fluorescence light microscopy. When three-dimensional images are collected using a conventional microscope, each observed section contains in-focus information from the parts of the sample at the focal plane and out-of-focus information from the remainder of the sample. The imaging process can be characterized as a convolution of the sample with the point spread function (PSF) of the microscope. We have experimentally determined the PSF for an epifluorescence microscope using high numerical aperture oil and water immersion lenses. Several methods for the processing of the observed data are discussed, with the best results obtained by constrainediterative deconvolution methods.
Why does so much FDI from Hong Kong and Taiwan go to Mainland China

Abstract While the European Union, the US, and Japan (the Triad) supply 90% of global foreign direct investment (FDI) and China is the second largest FDI recipient in the world, most FDI into China did not come from the Triad but from Hong Kong and Taiwan (HKT). Evidence presented in the paper reveals that the unusually large amount of Hong Kong–Taiwan direct investment (HKTDI) cannot be fully appreciated without understanding China's location characteristics and differences between HKTDI and the Triad FDI. Four determinants of the dominant HKTDI in China are identified: China's export-promotion FDI strategy, its large pool of cheap labor, HKT's specific advantages in export-oriented FDI, and their unique links with China (the Chinese connections). Empirical results suggest that HKTDI was primarily motivated by low labor costs while FDI from the Triad was market-oriented. As China's domestic markets become more open to foreign investors, the share of HKTDI may shrink and the importance of FDI from the Triad may rise.
Structure of isocitrate dehydrogenase with isocitrate, nicotinamide adenine dinucleotide phosphate, and calcium at 2.5-A resolution: a pseudo-Michaelis ternary complex

The structure of isocitrate dehydrogenase (IDH) with a bound complex of isocitrate, NADP+, and Ca2+ was solved at 2.5-A resolution and compared by difference mapping against previously determined enzymatic complexes. Calcium replaces magnesium in the binding of metal-substrate chelate complex, resulting in a substantially reduced turnover rate. The structure shows the following: (i) A complete, structurally ordered ternary complex (enzyme, isocitrate, NADP+, and Ca2+) is observed in the active site, with the nicotinamide ring of NADP+ exhibiting a specific salt bridge with isocitrate. The binding of the cofactor nicotinamide ring is dependent on this interaction. (ii) Isocitrate is bound by the enzyme with the same interactions as those found for the magnesium/substrate binary complex, but the entire molecule is shifted in the active site by approximately 1 A in order to accommodate the larger metal species and to interact with the nicotinamide ring. The distances from isocitrate to the bound calcium are substantially longer than those previously found with magnesium. (iii) NADP in the Escherichia coli IDH has a novel binding site and conformation as compared to previously solved dehydrogenases. (iv) The orientation and interactions of the nicotinamide ring with the substrate are consistent with the stereospecificity of the enzyme-catalyzed reaction.
C5b-9-induced Endothelial Cell Proliferation and Migration Are Dependent on Akt Inactivation of Forkhead Transcription Factor FOXO1

Migration and proliferation of aortic endothelial cells (AEC) are critical processes involved in angiogenesis, atherosclerosis, and postangioplasty restenosis. Activation of complement and assembly of the C5b-9 complement complex have been implicated in the pre-lesional stage of atherogenesis and progression of the atherosclerotic lesion. We have shown that C5b-9 induces proliferation and activates phosphatidylinositol 3-kinase (PI3K), but it is unknown whether this can lead to activation of Akt in AEC, a major downstream target of PI3K, or if C5b-9 can induce the migration of AEC, a critical step in angiogenesis. In this study, we show that C5b-9 induces AEC proliferation and migration and also activates the PI3K/Akt pathway. C5b-9 activates Akt as shown by in vitro kinase assay and phosphorylation of Ser-473. C5b-9-induced cell cycle activation was inhibited by pretreatment with LY294002 (PI3K inhibitor), SH-5 (Akt inhibitor), or transfection with Akt siRNA. These data suggests that the PI3K/Akt pathway is required for C5b-9-induced cell cycle activation. FOXO1, a member of forkhead transcription factor family, was phosphorylated at Ser-256 and inactivated after C5b-9 stimulation as shown by a decrease in DNA binding and cytoplasmic relocalization. Cytoplasmic relocalization was significantly reduced after pretreatment with LY294002, SH-5, or transfection with Akt siRNA. Silencing FOXO1 expression using siRNA stimulated AEC proliferation and regulated angiogenic factor release. Our data indicate that C5b-9 regulation of the cell cycle activation in AEC through Akt pathway is dependent on inactivation of FOXO1.
Tyr-179 and Lys-183 are essential for enzymatic activity of 11β-hydroxysteroid dehydrogenase

Abstract Tyr-179 and Lys-183 are likely to be functionally important residues in 11β-hydroxysteroid dehydrogenase, as thease amino acids are absolutely conserved in all members of the “short chain dehydrogenase” family. We modified these residues by site-directed mutagenesis of rat cDNA and transfected these constructs into CHO cells. A highly but not absolutely conserved residue, Asp-110, was also studied. Mutation of Tyr-179 to Phe or Ser completely abolished enzymatic activity (interconversion of corticosterone and 11-dehydrocorticosterone), as did Lys-183→Arg. Asp-110→Asn affected activity only mildly. Tyr-179 and Lys-183 may be directly involved in the catalytic function of this class of enzymes.
Regularized regression method for genome-wide association studies

We use a novel penalized approach for genome-wide association study that accounts for the linkage disequilibrium between adjacent markers. This method uses a penalty on the difference of the genetic effect at adjacent single-nucleotide polymorphisms and combines it with the minimax concave penalty, which has been shown to be superior to the least absolute shrinkage and selection operator (LASSO) in terms of estimator bias and selection consistency. Our method is implemented using a coordinate descent algorithm. The value of the tuning parameters is determined by extended Bayesian information criteria. The leave-one-out method is used to compute p-values of selected single-nucleotide polymorphisms. Its applicability to a simulated data from Genetic Analysis Workshop 17 replication one is illustrated. Our method selects three SNPs (C13S522, C13S523, and C13S524), whereas the LASSO method selects two SNPs (C13S522 and C13S523).
HIV-Associated Hodgkin's Lymphoma: Prognosis and Therapy in the Era of cART.

Patients with human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) are at increased risk for developing Hodgkin's lymphoma (HL), a risk that has not decreased despite the success of combination antiretroviral therapy (cART) in the modern era. HIV-associated HL (HIV-HL) differs from HL in non-HIV-infected patients in that it is nearly always associated with Epstein-Barr virus (EBV) and more often presents with high-risk features of advanced disease, systemic “B” symptoms, and extranodal involvement. Before the introduction of cART, patients with HIV-HL had lower response rates and worse outcomes than non-HIV-infected HL patients treated with conventional chemotherapy. The introduction of cART, however, has allowed for the delivery of full-dose and dose-intensive chemotherapy regimens with improved outcomes that approach those seen in non-HIV infected patients. Despite these significant advances, HIV-HL patients remain at increased risk for treatment-related toxicities and drug-drug interactions which require careful attention and supportive care to insure the safe administration of therapy. This paper will address the modern diagnosis, risk stratification, and therapy of HIV-associated HL.
Comparison of the expression of a mutant dihydrofolate reductase under control of different internal promoters in retroviral vectors.

ABSTRACT To determine the effect of different promoters on the expression of an altered dihydrofolate reductase (DHFR) gene conferring methotrexate (MTX) resistance in different cell types, double-...
Millisecond measurement of transport during and after an electroporation pulse

Electroporation involves the application of an electric field pulse that creates transient aqueous pathways in lipid bilayer membranes. Transport through these pathways can occur by different mechanisms during and after a pulse. To determine the time scale of transport and the mechanism(s) by which it occurs, efflux of a fluorescent molecule, calcein, across erythrocyte ghost membranes was measured with a fluorescence microscope photometer with millisecond time resolution during and after electroporation pulses several milliseconds in duration. One of four outcomes was typically observed. Ghosts were: (1) partially emptied of calcein, involving efflux primarily after the pulse; (2) completely emptied of calcein, involving efflux primarily after the pulse; (3) completely emptied of calcein, involving efflux both during and after the pulse; or (4) completely emptied of calcein, involving efflux primarily during the pulse. Partial emptying, involving significant efflux during the pulse, was generally not observed. We conclude that under some conditions transport caused by electroporation occurs predominantly by electrophoresis and/or electroosmosis during a pulse, although under other conditions transport occurs in part or almost completely by diffusion within milliseconds to seconds after a pulse.
Fermi-level unpinning on GaAs (111)A surface with direct ALD Al 2 O 3

Although high-performance inversion-mode InGaAs NMOSFETs are demonstrated1–6, highperformance GaAs MOSFETs with directly deposited high-k dielectrics remain a big challenge. Some researchers believe that Fermi-level of GaAs is intrinsically pinned at the mid-gap with directly deposited ALD Al 2 O 3 . In this paper, we systematically study the electrical properties of ALD Al 2 O 3 NMOSCAPs, PMOSCAPs, NMOSFETs and PMOSFETs on GaAs (111)A and use (100) as a reference. (111)A is a pure Ga polar surface instead of (100) Ga-As unpolar surface. The results obtained on GaAs (111)A surface are astonishingly different from those on GaAs (100) surface. Multi-probe investigations confirm that Fermi-level of GaAs is unpinned with direct ALD Al 2 O 3 .
Two-component regulator of Enterococcus faecalis cytolysin responds to quorum-sensing autoinduction

Bacteria of the genus Enterococcus are the main causes of highly antibiotic-resistant infections that are acquired in hospitals. Many clinical isolates of Enterococcus faecalis produce an exotoxin called cytolysin that contributes to bacterial virulence. In addition to its toxin activity, the cytolysin is bactericidal for nearly all Gram-positive organisms. An understanding of conditions that regulate cytolysin expression has advanced little since its initial description. Here we show that the products of two genes, cylR1 and cylR2, which lack homologues of known function, work together to repress transcription of cytolysin genes. Derepression occurs at a specific cell density when one of the cytolysin subunits reaches an extracellular threshold concentration. These observations form the basis of a model for the autoinduction of the cytolysin by a quorum-sensing mechanism involving a two-component regulatory system.
Generalized paired-echo analysis for bandpass systems

A generalized form of paired-echo analysis suitable for application to bandpass systems has been developed. This method is suitable for digital-computer application and provides an efficient technique for wave-form computation.
Genetics of smoking behavior

More than one in five American adults still smokes despite the availability of effective smoking cessation medication. Genetic predisposition to treatment response, termed pharmacogenetics, offers a potential (if partial) solution to this widespread public health problem. Recent genomewide association studies have identified a group of “quit-success genes” that are specific for predicting response to bupropion versus nicotine replacement therapy. However, additional research is needed to replicate and refine these exciting discoveries; their medical practice and policy implications are vast. A public health infrastructure is not yet in place to translate the knowledge of quit-success genes into primary care practice, where most smoking cessation treatment takes place.
Position-Dependent Ventricular Tachycardia Related to a Peripherally Inserted Central Catheter

Recently, peripherally inserted central venous catheters (PICCs) have been widely used for venous access. Advantages of a PICC over centrally inserted central catheters include the virtual elimination of the risk of pneumothorax, hemothorax, and arterial puncture, along with a reduced risk of bleeding. However, the PICC has associated risks. We present 2 cases of body position-dependent ventricular tachycardia related to PICCs. These events occurred in patients with no prior history of cardiac arrhythmia and were corrected by repositioning of the PICC. They serve to identify a potentially serious cardiac complication of the PICC that, to our knowledge, has not been described previously.
Characterization of high-finesse mirrors: Loss, phase shifts, and mode structure in an optical cavity

An extensive characterization of high-finesse optical cavities used in cavity QED experiments is described. Different techniques in the measurement of the loss and phase shifts associated with the mirror coatings are discussed and their agreement shown. Issues of cavity-field mode structure supported by the dielectric coatings are related to our effort to achieve the strongest possible coupling between an atom and the cavity.
Phase I‐II trial of percutaneous intra‐arterial Cis‐diamminedichloro platinum (II) for regionally confined malignancy

Forty-nine patients with regionally confined recurrent malignancy were treated with intra-arterial cis-diamminedichloro platinum II in a Phase I-II trial. A safe starting dose of 120 mg/m2 was established. An overall response rate of 45% was noted with significant responses observed among patients with melanoma, sarcoma, breast carcinoma, and neuroblastoma. Side effects included transient renal and bone marrow toxicity as well as neurotoxicity and ototoxicity (6%), the latter usually with residual damage. The rational basis and advantages of treatment with intra-arterial cis-platinum are discussed.
Motifs for molecular recognition exploiting hydrophobic enclosure in protein–ligand binding

The thermodynamic properties and phase behavior of water in confined regions can vary significantly from that observed in the bulk. This is particularly true for systems in which the confinement is on the molecular-length scale. In this study, we use molecular dynamics simulations and a powerful solvent analysis technique based on inhomogenous solvation theory to investigate the properties of water molecules that solvate the confined regions of protein active sites. Our simulations and analysis indicate that the solvation of protein active sites that are characterized by hydrophobic enclosure and correlated hydrogen bonds induce atypical entropic and enthalpic penalties of hydration. These penalties apparently stabilize the protein-ligand complex with respect to the independently solvated ligand and protein, which leads to enhanced binding affinities. Our analysis elucidates several challenging cases, including the super affinity of the streptavidin-biotin system.
The cardiorespiratory effects of perfluorochemicals on acute carbon monoxide poisoning in the pregnant ewe

Studies in nonpregnant animal models of carbon monoxide poisoning have demonstrated the protective effect of perfluorochemicals. Anesthetized pregnant ewes were exposed to carbon monoxide. After symptoms of toxicity were demonstrated, group 1 animals were respired with room air. Group 2 animals respired room air and were given intravenous perfluorochemicals. Group 3 animals were administered 100% oxygen. Group 4 animals were given intravenous perfluorochemicals and respired 100% oxygen. In all ewes exposure to carbon monoxide resulted in increased cardiac output, heart rate, and carboxyhemoglobin level without a significant change in arterial oxygen tension. After carbon monoxide exposure, there was no significant difference in the carboxyhemoglobin to oxyhemoglobin conversion between groups 1 and 2 although the conversion rates were more rapid in groups 3 and 4. Fetal oxygenation was improved in groups 3 and 4. All fetal lambs exhibited a progressive increase in carboxyhemoglobin and a decrease in venous pH regardless of the maternal postexposure treatment. There was no significant increase in the fetal venous oxygen content of group 4 as compared with that of group 3, suggesting that the adjunctive administration of limited quantities of perfluorochemicals to the mother offers no apparent advantage over 100% oxygen alone for acute fetal resuscitation.
The role of primary tumour resection in patients with stage IV colorectal cancer.

Objective The management of stage IV colorectal cancer is controversial. Resection of the primary tumour to prevent obstruction, bleeding or perforation is the traditional approach, although survival benefit is undetermined. Management consisting of diverting ostomy, enteric bypass, laser recanalization or endoscopic stenting is an alternative to radical resection. The purpose of this study was to determine the role of resection of the primary tumour in patients with stage IV colorectal cancer, with specific attention paid to survival benefit and safety. Method This was a retrospective review of all stage IV colon and rectal cancer patients in our tumour registry between 1991 and 2002. Data collected included patient demographics, presenting symptoms, detail from the hospital course including diagnostic data and operative management, complications and survival time (days). Survival analysis was performed to assess the effect of primary tumour resection on long-term survival. Results 109 patients were studied. Sixty-two (57%) patients (group I) underwent resection of the primary tumour, whereas 47 (43%) patients (group II) were managed without resection. Median survival times for groups I and II were 375 (IQR: 179–759) and 138 (IQR: 35–262) days respectively (P < 0.0001). After controlling for age, sex, tumour location and level of liver involvement as well as liver function, patients who underwent resection still survived longer (HR = 0.34, 95% CI: 0.21–0.55). Conclusion Palliative resection of the primary tumour plays an essential role in the management of stage IV colorectal cancer. Resection can offer increased survival and is indicated in certain patients with incurable disease. Limited metastatic tumour burden of the liver was associated with better survival in such patients.
Pitfalls in the echographic evaluation of pancreatic disease.

Ultrasound has gained widespread acceptance in the evaluation of pancreatic disease. Echographic criteria for the diagnosis of pancreatitis, pseudocyst, and pancreatic carcinoma are presented. Additionally, three important areas of difficulty in the echographic evaluation of pancreatic disease are described.
DECIPHERING THE HIPPOCAMPAL POLYGLOT: THE HIPPOCAMPUS AS A PATH INTEGRATION SYSTEM

Hippocampal 'place' cells and the head-direction cells of the dorsal presubiculum and related neocortical and thalamic areas appear to be part of a preconfigured network that generates an abstract internal representation of two-dimensional space whose metric is self-motion. It appears that viewpoint-specific visual information (e.g. landmarks) becomes secondarily bound to this structure by associative learning. These associations between landmarks and the preconfigured path integrator serve to set the origin for path integration and to correct for cumulative error. In the absence of familiar landmarks, or in darkness without a prior spatial reference, the system appears to adopt an initial reference for path integration independently of external cues. A hypothesis of how the path integration system may operate at the neuronal level is proposed.
No Small Thing: School District Central Office Bureaucracies and the Implementation of New Small Autonomous Schools Initiatives

New small autonomous schools initiatives are relatively recent educational change strategies that in some urban districts aim to remake how district central offices function as institutions. In this article, the author draws on theories of organizational innovation and learning to reveal how central office administrators participate in these change processes, what outcomes are associated with their efforts, and the conditions that help or hinder their work. The data came from a 3-year qualitative investigation of these dynamics in two districts. The results show that particular bridging and buffering activities by certain central office administrators were consistent with policy goals and linked to increasing district supports for implementation. Particular dimensions of the institutional environments of central offices shaped central office administrators’ choices and actions.
Differential role of the orbital frontal lobe in emotional versus cognitive perspective-taking

Lesions of the orbital frontal lobe, particularly its medial sectors, are known to cause deficits in empathic ability, whereas the role of this region in theory of mind processing is the subject of some controversy. In a functional magnetic resonance imaging study with healthy participants, emotional perspective-taking was contrasted with cognitive perspective-taking in order to examine the role of the orbital frontal lobe in subcomponents of theory of mind processing. Subjects responded to a series of scenarios presented visually in three conditions: emotional perspective-taking, cognitive perspective-taking and a control condition that required inferential reasoning, but not perspectivetaking. Group results demonstrated that the medial orbitofrontal lobe, defined as Brodmann’s areas 11 and 25, was preferentially involved in emotional as compared to cognitive perspective-taking. This finding is both consistent with the lesion literature, and resolves the inconsistency of orbital frontal findings in the theory of mind literature. © 2005 Elsevier Ltd. All rights reserved.
Stochastic calculation of interaction energies

A Monte Carlo method by which the properties of a collection of interacting nuclei and electrons might be accurately calculated is briefly outlined. This method allows quantitative determination of the pairwise intermolecular potential and potential surfaces but eliminates the use of these constructs for dense systems. Preliminary results on the electron gas, hydrogen solid, and the molecules He/sub 2/, LiH, Li/sub 2/, and H/sub 2/O are at least as accurate as the best previous work.
Evidence for a stable interaction of gp41 with Pr55(Gag) in immature human immunodeficiency virus type 1 particles.

Assembly of infectious human immunodeficiency virus type 1 (HIV-1) virions requires incorporation of the viral envelope glycoproteins gp41 and gp120. Several lines of evidence have suggested that the cytoplasmic tail of the transmembrane glycoprotein, gp41, associates with Pr55Gag in infected cells to facilitate the incorporation of HIV-1 envelope proteins into budding virions. However, direct evidence for an interaction between gp41 and Pr55Gag in HIV-1 particles has not been reported. To determine whether gp41 is associated with Pr55Gag in HIV-1 particles, viral cores were isolated from immature HIV-1 virions by sedimentation through detergent. The cores contained a major fraction of the gp41 that was present on untreated virions. Association of gp41 with cores required the presence of the gp41 cytoplasmic tail. In HIV-1 particles containing a functional protease, a mutation that prevents cleavage of Pr55Gag at the matrix-capsid junction was sufficient for the detergent-resistant association of gp41 with the isolated cores. In addition to gp41, a major fraction of virion-associated gp120 was also detected on immature HIV-1 cores. Isolation of cores under conditions known to disrupt lipid rafts resulted in the removal of a raft-associated protein incorporated into virions but not the HIV-1 envelope proteins. These results provide biochemical evidence for a stable interaction between Pr55Gag and the cytoplasmic tail of gp41 in immature HIV-1 particles. Moreover, findings in this study suggest that the interaction of Pr55Gag with gp41 may regulate the function of the envelope proteins during HIV-1 maturation.
Political leanings vary with facial expression processing and psychosocial functioning

Conservative, Republican sympathizers show heightened threat reactivity, but greater felt happiness than liberal, Democrat sympathizers. Recent evolutionary models interpret these findings in the context of broader perceptual and expressive proclivities for advertising cues of competency (Republicans) and trustworthiness (Democrats) to others, and in ways that facilitate the formation of distinct social networks, in coordination with individuals’ life histories. Consistent with this perspective, I found that Republican sympathizers were more likely to report larger social networks and interpret ambiguous facial stimuli as expressing more threatening emotions as compared to Democrat sympathizers, who also reported greater emotional distress, relationship dissatisfaction, and experiential hardships. The findings are discussed in the context of proximate and ultimate explanations of social cognition, relationship formation, and societal cohesion.
Methoxylation enhances stilbene bioactivity in Caenorhabditis elegans

Background Stilbenes are 1,2-diphenylethylene congeners produced by plants in response to stress. Many stilbenes also exhibit xenobiotic activities in animal cells, such as inhibition of cancer cell growth, neuroprotection, and immune modulation. In vivo, hydroxylated stilbenes are metabolized by glucuronidation to facilitate excretion. Methoxylated stilbenes are metabolized more slowly, which may have a positive effect on in vivo bioactivity. Here, we have directly compared in vivo bioactivities of methoxylated and hydroxylated stilbenes in a whole organism using the roundworm Caenorhabditis elegans, an advantageous experimental system for such studies due to its rapid lifecycle, genetic amenability and relatively low-cost.
When the Medial Prefrontal Cortex Fails: Implications for Extinction and Posttraumatic Stress Disorder Treatment

Anxiety disorders such as posttraumatic stress disorder (PTSD) are characterized by a failure to inhibit maladaptive affective and visceral responses associated with environmental stimuli. One of the best-studied examples of this adaptive learning is fear extinction. In extinction, reexposure to a
Hadron production from quark coalescence and jet fragmentation

Transverse momentum spectra of pions, protons, and antiprotons in $\mathrm{Au}+\mathrm{Au}$ collisions at intermediate RHIC energy $\sqrt{{s}_{\mathit{NN}}}=62\phantom{\rule{0.3em}{0ex}}\mathrm{GeV}$ are studied in a model that includes both quark coalescence from the dense partonic matter and fragmentation of the quenched perturbative minijet partons. The resulting baryon to meson ratio at intermediate transverse momenta is predicted to be larger than that seen in experiments at higher center of mass energies.
A laboratory exercise to illustrate increased salivary cortisol in response to three stressful conditions using competitive ELISA

Perceived stress activates the hypothalamus-pituitary-adrenal axis, resulting in the release of glucocorticoids into the systemic circulation. Glucocorticoids cause the elevation of blood glucose, providing the necessary energy for the organism to cope with stress. Here, we outline a laboratory exercise that uses a competitive ELISA kit to illustrate the response of salivary cortisol concentrations to three stressful conditions. Twelve undergraduate students in the General and Comparative Endocrinology course at Iowa State University were subjected to presentation stress, fasting stress, and competition stress to determine their effect on salivary cortisol concentrations. Students had elevated salivary cortisol in response to each of these stresses compared with basal conditions. These results reiterate the importance of glucocorticoids as mediators of the stress response. This study also incorporates the use of the ELISA technique, a modern laboratory tool used to determine the amount of endogenous antigens in plasma or saliva. This laboratory exercise can easily be adapted to fit into already existing physiology and endocrinology curriculums.
The division of parent care between spouses

Research on the division of family work has focused on household work and child-care to the exclusion of other domains, whereas studies on care-giving for older people typically ignore spouses' support to care-givers. In this paper we apply an approach that is typical of research on spouses' division of family work in caring for parents, in that the theoretical model focuses on the ‘cultural mandates’ that guide spouses' division of care, namely gender ideologies about appropriate roles, kinship obligations, and taboos against cross-gender personal care. Other predictors of the spousal division of care drawn from economic and health-care utilisation models are also examined. The analyses use pooled data on 1,449 care occasions from the first five waves of the US Health and Retirement Study. It was found that most couples to some extent share parent care, and that the involvement of husbands depended on a complex interplay of cultural mandates and contexts. Husbands participated most in personal care for parents if the care was mandated by kinship obligations (they cared more for their own than their wife's parents), and by cross-gender care taboos (they cared more for fathers than mothers). Other cultural contexts (such as race), a spouse's other commitments, health-related ability, resources (including support from the parents' other children), and care-burden also played a role. The findings demonstrate that decisions to care for parents emerge from complex negotiations among spouses and their children and siblings or, in other words, that parental care is a family endeavour.