cssi/SciSciGPT-SciSciNet huggingface dataset:
Reconstructing public diplomacy in the context of policy, communication, and technology: An examination of U.S. ‐ Mexico border relations

Abstract As the United States implements more stringent measures to secure its border with Mexico, the perception of the United States in Mexico has turned negative. Despite Mexico's strategic importance, public diplomacy has not been well utilized in the United States, specifically as it pertains to the U.S.‐Mexico border. Moreover, policy efforts have not effectively addressed this issue. The United States ought utilize technological resources to encourage communication facilitating public diplomacy with Mexico. In this way, the United States could lessen the negative public opinion of it throughout Mexico.
Low-cycle fatigue in Ni3Al-based alloys

The low-cycle fatigue properties of hot-extruded powders of a Ni3Al-based alloy, IC 218, with nominal composition Ni-16.5Al-8.0Cr-0.4Zr-0.1B (at %) have been evaluated at room temperature. Tests were conducted under total strain conditions in a laboratory air environment. Results indicate that the low-cycle fatigue performance of the PM processed IC 218 nickel aluminide is superior to other structural alloys especially at higher strain amplitudes. These results are explained in terms of the high ductility of the fine-grain material and good crack growth propagation resistance in these alloys. Stress response curves for annealed IC 218 alloys indicate considerable cyclic hardening followed by cyclic softening. The onset of cyclic softening is found to occur at a constant cumulative plastic strain. The critical cumulative plastic strain criteria are verified for step-loaded IC 218 nickel aluminide coupons.
Comparative measurement of stem flow and transpiration in cotton

Whole-plant transpiration (T) measurements have many applications, but appropriate methods have remained somewhat elusive. A new method using a constant power heat balance gauge, wherein the xylem mass flow rate is calculated from a balance of heat into and out of a stem, has been shown to provide accurate stem flow measurements. To evaluate the applicability of this promising method to field experiments, cotton (Gossypium hirsutum L. “GP 3774”) stem flow measurements were compared withT measured from a weighing lysimeter. Initially to confirm method accuracy, stem flow values were compared in the glasshouse withT values determined by mass measurements of a potted plant. The root mean square error (RMSE) between the daylight losses from both (n = 16) was 8.6% of the mean measuredT values. In the field, hourly stem flow and lysimeterT values were also similar, but there was a large variation in stem flow values among the different plants. To account for differences in plant size between the plants with gauges and all lysimeter plants, stem flow values were adjusted using a stem area ratio factor, which adjusted values, on the average for the season, by 25%. Before adjustment, daylight stem flow totals were consistently greater than lysimeterT values. After adjustment, the means differed by only 9%, and theRMSE was reduced from 129 to 69 g plant−1 d−1. The coefficient of variation of daylight stem flow totals increased throughout the season. In the glasshouse, method accuracy was comparable (errors < ± 10%) to what has been previously determined. In the field, determining method accuracy was confounded by plant-to-plant variability and, possibly, by errors, unique to the gauge design used in this study, at high flow rates. Thus, this method can provide accurate flow measurements from individual herbaceous plants and is a valuable technique for many applications.
Constitutive activation of opsin by mutation of methionine 257 on transmembrane helix 6.

Rhodopsin is a member of the large family of G protein-coupled receptors (GPCR's). Constitutive activity of GPCR's, defined as ligand-independent signaling, has been recognized as an important feature of receptor function and has also been implicated in the molecular pathophysiology of a number of human diseases. Rhodopsin has evolved a unique mechanism to minimize receptor basal activity. The chromophore 11-cis-retinal, which acts as an inverse agonist in rhodopsin, is covalently bound to the receptor to ensure extremely low receptor signaling in the dark. In this study, we replaced Met257 in TM helix 6 of opsin with each of the remaining 19 amino acids. Only mutant opsin M257R failed to be expressed in COS-cell membranes. Each of the remaining 18 mutant opsins, with the exception of M257L, was significantly constitutively active. Two mutants in particular, M257Y and M257N, displayed very high levels of constitutive activity. In addition, the double-site mutants with substitutions of both Met257 and Glu1...
Hypertension targets: a focus on the artery, the kidney and the heart

2012 Annual Scientific Meeting and Exposition of the American Society of HypertensionNew York, NY, USA, 19–22 May 2012For the last several years, the annual American Society of Hypertension meeting has held a segment called ‘Hypertension Highlights’ featuring state-of-the art talks by leaders in the field who share current research, and clinical management, organized around themes in hypertension. This year there were nine lectures grouped into three domains: the artery, the kidney and the heart.
Surgical management of the neck in oral cancer.

History of neck dissections for oral cancer Surgical removal of the cervical lymph nodes plays an important role in the comprehensive management of squamous cell carcinoma of the oral cavity. Two of the most important aspects of the assessment of patients with these cancers include the clinical evaluation of the lymph nodes of the neck and the prediction of occult neck disease in the case of a clinically negative neck. Occult neck disease is defined as disease that is present microscopically but cannot be palpated clinically and may defy identification by special imaging studies. As such, patients deemed to have occult neck disease were staged as N0 clinically and underwent elective surgical dissection of their cervical lymph nodes with the histopathologic identification of positive nodes (pNþ). It is the philosophy of these authors, and that of most, that elective surgical removal of the cervical lymph nodes that are clinically negative (N0) should be executed liberally with curative intent. Oral cancer is most commonly treated surgically, so it is most appropriate that the neck also be treated surgically, with radiotherapy being added postoperatively when pathologic evidence so dictates [1]. Observing the N0 neck, only to operate on the neck in the case of future, clinically apparent nodal disease is oncologically unsafe in most cases of oral squamous cell cancer. This statement is based on the realization that salvage rates for these patients are unfavorable. To this end, Warren in 1839 recommended removal of lymph nodes in the submandibular triangle associated with tongue cancer in the best
Evaluation of Left Ventricular Filling Pressures by Doppler Echocardiography in Patients With Hypertrophic Cardiomyopathy Correlation With Direct Left Atrial Pressure Measurement at Cardiac Catheterization

Background— Diastolic dysfunction is a major pathophysiological abnormality in hypertrophic cardiomyopathy (HCM). Doppler echocardiographic parameters correlate with left ventricular (LV) filling pressures in other diseases, but it is unclear whether these findings apply to patients with HCM, who have multiple complex interrelated events leading to diastolic dysfunction. This study compares Doppler echocardiographic estimates of filling pressures to direct measurements of left atrial pressure (LAP) via catheterization in 100 patients with HCM. Methods and Results— One hundred patients who were symptomatic with HCM (New York Heart Association class III/IV, 82%) underwent measurement of early diastolic transmitral flow velocity (E) and mitral annular velocities (e′) with the use of transthoracic echocardiography within 48 hours of cardiac catheterization with direct measurement of LAP. In a subset of 42 patients, echocardiographic and catheterization measurements were performed simultaneously. Mean LAP dire...
CAPS: A language for modeling highly skilled knowledge-intensive behavior

CAPS is a computer language specialized for modeling highly skilled and knowledge-intensive human activities such as reading (Thibadeau, Just, & Carpenter, 1982). The present paper provides a critical analysis of the particular style of psychological modeling of which CAPS is an example. Suggestions are presented for modeling environments for psychologists.
Mercury sources and cycling in the Connecticut River and Long Island Sound

Long Island Sound (LIS) is one of the “Great Waters” of the United States, and one of the world's most productive and utilized water bodies. It is a classic “urban sea” with about 16 million people living and working near its shores. Commercial, industrial, and recreational uses of LIS abound, as do current and historic pollution from heavy metals, nutrients, and organic chemicals. Mercury cycling in such anthropogenically impacted near shore and fisheries-rich systems is poorly understood. Here, we are presenting a well-constrained assessment of the status and impact from contamination on the behavior and fate of Hg in LIS. Mercury (Hg), as with many substances in the Sound, is affected by localized discharges (e.g., rivers, water pollution control facilities [WPCFs]), and direct and indirect (i.e., watershed leaching) inputs from airborne transport and deposition of Hg. Agreement in total Hg (14–21 pM) and monomethylmercury (MMHg; 0.5–0.9 pM) levels (1995–1997) among the major rivers (Connecticut [CTR], Housatonic, and Thames) entering LIS suggests that deposition and subsequent leaching of atmospherically derived Hg from the respective watersheds accounts for much of the river fluxes. Although CT WPCF effluents contain varying amounts of HgT and MMHg, effluent from major CT WPCFs discharging to the CTR (Hartford and Mattabassett-Cromwell) contain similar amounts of total Hg (60–92 pM) and MMHg (1.5–2.1 pM), which are elevated compared to river concentrations. However, only a minor portion (2% of HgT flux) of Hg in the CTR is derived from CT WPCFs. Similarity in the atmospheric Hg flux (wet+dry deposition; 40±10 nmol HgT m−2 year−1) among sampling sites (Groton, Madison, Milford, CT; Rye, NY) points to the importance of long-range transport and deposition of Hg to this coastal region. The principal sources of total Hg (1160 mol year−1) to LIS are rivers entering from CT (∼680 mol year−1; 59% of total inputs), the East River (∼290 mol year−1; 25%; 110 mol year−1 from New York City WPCFs), WPCFs (∼60 mol year−1; 5%), and direct atmospheric deposition (∼130 mol year−1; 11%). Although direct atmospheric Hg deposition to LIS is small, modest leaching (25–30% watershed delivery; 410–490 mol Hg year−1) of the Sound-wide atmospheric deposition normalized to its watershed could account for 60–75% of river Hg inputs. Principal external sources of MMHg to LIS (28 mol year−1) include rivers entering from CT (∼15 mol year−1), the East River (∼6.0 mol year−1), and direct atmospheric deposition (∼3.5 mol year−1); MMHg concentrations are typically only 2% of HgT. In situ sedimentary production is predicted to be the major source of MMHg in LIS, with an estimated sediment–water flux of 55±20 mol MMHg year−1 (70% of total inputs).
Neither Relative nor Universal: A Response to Donnelly

This response raises questions about Jack Donnelly’s argument for the “relative universality” of human rights. It shows that Donnelly’s reliance on the terms relative and universal dulls many of his sharp analytic points and in some instances leads to inconsistencies in his account. This response also contends that in defending the relative universality of human rights Donnelly obscures or mischaracterizes the bases of their legitimacy. It concludes by arguing that human rights are neither relative nor universal and shows how abandoning this vocabulary would improve our theoretical understanding of them.
A Noninvasive Approach to Quantitative Functional Brain Mapping with H215O and Positron Emission Tomography

Positron emission tomographic (PET) measurements of regional cerebral blood flow (rCBF) with intravenously administered 15O-labeled water and an adaptation of the Kety autoradiographic model are well suited to the study of functional-anatomical correlations within the human brain. This model requires arterial blood sampling to determine rCBF from the regional tissue radiotracer concentration (Cr) recorded by the tomograph. Based upon the well-defined, nearly linear relation between Cr and rCBF inherent in the model, we have developed a method for estimating changes in rCBF from changes in Cr without calculating true rCBF and thus without arterial sampling. This study demonstrates that quantitative functional brain mapping does not require the determination of rCBF from Cr when regional neuronal activation is expressed as the change in rCBF from an initial, resting-state measurement. Patterned-flash visual stimulation was used to produce a wide range of increases in rCBF within the striate cortex. Changes in occipital rCBF were found to be accurately estimated directly from Cr over a series of 56 measurements on eight subjects. This adaptation of the PET/autoradiographic method serves to simplify its application and to make it more acceptable to the subject.
Dose-dependent response of mature cerebrovascular axons in vivo following intracranial infusion of nerve growth factor.

The perivascular axons associated with the intradural segment of the internal carotid artery undergo a sprouting response following intracerebroventricular infusion of nerve growth factor (NGF). The objective of the present study was to determine whether a relationship exists between the number of sprouted axons and the amount of NGF infused into the ventricular system. Using regression analysis, we observed a significant log-log relationship between the dose of NGF and number of axons. No significant relationship was observed for the control (VEH) group. A significant increase in axonal number was observed following infusion of 3.0 μg NGF and higher when compared with VEH treatment of similar concentration. Results of this analysis suggest that a maximal response to NGF is approximated at doses of 15 μg or higher. These findings suggest a dose-dependent relationship between the response of mature sympathetic cerebrovascular axons in vivo and the dose of exogenous NGF.
DNA double-strand breaks and hairpins in V(D)J recombination

Abstract Several lines of evidence have suggested the existence of broken DNA molecules as intermediates in V(D)J recombination. These include sequence alterations at the recombined junctions and the presence of aberrant recombinants. More recently, broken DNA molecules have been directly detected in recombinationally active cells. The signal sequence ends have normal blunt-ended DNA breaks, but the coding ends have a hairpin (self-joined) structure that provides an explanation for the self-complementary P nucleotide insertions often found after V(D)Joining in the antigen receptor genes.
Incorporation of purines and purine precursors into the nucleotide pool of isolated bone cells.

1. 1. A heterogeneous population of bone cells, isolated from neonatal rat calvaria. did not incorporate [14C]formate or [14C]glycine into adcnine and guanine of either the acid-soluble (nucleotide) or acid-insoluble (RNA)fractions. 2. 2. Cells supplemented with l-ribosyl-4-carboxamide-5-aminoimidazole did incorporate [14C]formate into the two purines of both fractions. These results indicate that bone cells have a limited capacity for purine biosynthesis de novo. 3. 3. Isolated bone cells did incorporate [14C]adenine. [14C]guanine and [14C]hypoxanthine into their nuclcotide pools indicating the presence in these cells of the purine phosphoribosyltransferases. 4. 4. The presence of various other enzymes of purine metabolism was implied from the observed interconversions of [14C]compounds formed from these free bases. 5. 5. [14C]Adenosine was extensively degraded by the isolated bone cells although it did contribute to the adenine nucleotide pool implying the presence in the cells of adenosine kinase. 6. 6. [14C]Hypoxanthine formed from this substrate was not converted to IMP. possibly because of the decreased availability of phosphoribosylpyrophosphate in the presence of adenosine. 7. 7. Preliminary experiments with calcitonin indicated that the conversion of hypoxanthinc formed from adenosine to IMP takes place in the presence of this hormone, due. presumably, to increased cellular Pi levels and therefore, the availability of phosphoribosylpyrophosphate.
When to drill? Trigger prices for the Arctic National Wildlife Refuge

Abstract The social net benefit of drilling for oil in the Arctic National Wildlife Refuge (ANWR) has been a contentious policy issue since 1998. This paper applies real option theory to the issue and asks “What price for crude oil would justify the investment in field development and the loss of an amenity (wilderness) dividend?” Trigger prices are identified for two stochastic processes; when crude oil prices evolve according to geometric Brownian motion (GBM) and when crude oil prices are mean-reverting (M-R).
Evidence for an early G1 ionic event necessary for cell cycle progression and survival in the MCF-7 human breast carcinoma cell line.

The mechanism of the G0/G1 arrest and inhibition of proliferation by quinidine, a potassium channel blocker, was investigated in a tissue culture cell line, MCF-7, derived from a human breast carcinoma. The earliest measurable effect of quinidine on the cell cycle was a decrease in the fraction of cells in S phase at 12 hr, followed by the accumulation of cells in G1/G0 phases at 30 hr. Arrest and release of the cell cycle established quinidine as a cell synchronization agent, with a site of arrest in early G1 preceding the lovastatin G1 arrest site by 5–6 hr. There was a close correspondence among the concentration-dependent arrest by quinidine in G1, depolarization of the membrane potential, and the inhibition of ATP-sensitive potassium currents, supporting a model in which hyperpolarization of the membrane potential and progression through G1 are functionally linked. Furthermore, the G1 arrest by quinidine was overcome by valinomycin, a potassium ionophore that hyperpolarized the membrane potential in the presence of quinidine. With sustained exposure of MCF-7 cells to quinidine, expression of the Ki67 antigen, a marker for cells in cycle, decreased, and apoptotic and necrotic cell death ensued. We conclude that MCF-7 cells that fail to progress through the quinidine-arrest site in G1 die. J. Cell. Physiol. 176:456-464, 1998. © 1998 Wiley-Liss, Inc.
A combination chemical and enzymatic approach for the preparation of azole carboxamide nucleoside triphosphate.

Alternative substrates for DNA and RNA polymerases offer an important set of biochemical tools. Many of the standard methods for nucleoside triphosphate synthesis fail in the cases of nonpurine and nonpyrimidine nucleosides. An efficient preparation of the 5‘-O-tosylates for both the deoxy- and ribonucleosides enabled preparation of the diphosphate esters by displacement with tris(tetra-n-butylammonium) pyrophosphate. Enzymatic synthesis of the azole carboxamide deoxyribonucleoside triphosphate was based on ATP as the phosphate donor, nucleoside diphosphate kinase as the catalyst, coupled with phosphoenol pyruvate (PEP) and pyruvate kinase as an ATP regeneration system. Ribonucleoside triphosphate synthesis required PEP as the phosphate donor and pyruvate kinase as the catalyst. An optimized purification procedure based upon boronate affinity gel was developed to yield highly purified nucleoside triphosphates. The strategy outlined here provides a new and efficient method for preparation of nucleoside 5‘-...
Sialyltransferase inhibitors: consideration of molecular shape and charge/hydrophobic interactions

In order to evaluate the importance of molecular shape of inhibitor molecules and the charge/H-bond and hydrophobic interactions, we synthesized three types of molecules and tested them against a sialyltransferase. The first type of compounds were designed as substrate mimics in which the phosphate in CMP-Neu5NAc was replaced by a non-hydrolysable, uncharged 1,2,3-triazole moiety. The second type of compound contained a 2-deoxy-2,3-dehydro-acetylneuraminic moiety which was linked to cytidine through its carboxylic acid and amide linkers. In the third type of compound the sialyl phosphate was substituted by an aryl sulfonamide which was then linked to cytidine. Inhibition study of these cytidine conjugates against Campylobacter jejuni sialyltransferase Cst 06 showed that the first type of molecules are competitive inhibitors, whereas the other two could only inhibit the enzyme non-competitively. The results indicate that although the binding specificity may be guided by molecular shape and H-bond interaction, the charge and hydrophobic interactions contributed most to the binding affinity.
Development and Expression of Hormonal Systems Regulating Aggression

There are multiple pathways involved in the regulation of male typical aggression by T, and the functional pathway is determined by genotype. Target-tissue sensitivity to the aggression-promoting properties of T and its estrogenic and androgenic metabolites is determined by a complex sequence of events in which steroid receptors play a critical role. To date, it appears that the relative density of AR may be an important factor in the biobehavioral effects of androgens. Regarding sensitivity to estrogens, characterization of ER-NM interactions, and understanding of the contribution of the two activating functions within ER, appears to be necessary to comprehensively describe the cellular basis for responsiveness to the aggression-promoting effect of this T metabolite. In broader terms, these observations indicate that understanding the relationship between T and the expression of aggression in humans will require models that incorporate cellular aspects of steroid hormone action, including metabolism, receptor function, and gene regulation. Language: en
Weighted Feature Subset Non-negative Matrix Factorization and Its Applications to Document Understanding

Keyword (Feature) selection enhances and improves many Information Retrieval (IR) tasks such as document categorization, automatic topic discovery, etc. The problem of keyword selection is usually solved using supervised algorithms. In this paper, we propose an unsupervised approach that combines keyword selection and document clustering (topic discovery) together. The proposed approach extends non-negative matrix factorization (NMF) by incorporating a weight matrix to indicate the importance of the keywords. The proposed approach is further extended to a weighted version in which each document is also assigned a weight to assess its importance in the cluster. This work considers both theoretical and empirical weighted feature subset selection for NMF and draws the connection between unsupervised feature selection and data clustering. We apply our proposed approaches to various document understanding tasks including document clustering, summarization, and visualization. Experimental results demonstrate the effectiveness of our approach for these tasks.
Nuclear orientation and nuclear structure

The present generation of on-line nuclear orientation facilities promises to revolutionize the gathering of nuclear structure information, especially for the hitherto poorly known and understood nuclei far from stability. Following a brief review of the technological developments that have facilitated these experiments, the nuclear spectroscopic information that can be obtained is summarized. Applications to understanding nuclear structure are reviewed, and challenges for future studies are discussed.
What do seniors remember from freshman physics

We have given a group of 56 Massachusetts Institute of Technology (MIT) seniors who took mechanics as freshmen a written test similar to the final exam they took in their freshman course as well as the Mechanics Baseline Test (MBT) and the Colorado Learning Attitudes about Science Survey (CLASS). Students in majors unrelated to physics scored 60% lower on the written analytic part of the final than they would have as freshmen. The mean score of all participants on the MBT was insignificantly changed from their average on the posttest they took as freshmen. However, the students' performance on 9 of the 26 MBT items (with 6 of the 9 involving graphical kinematics) represents a gain over their freshman posttest score (a normalized gain of about 70%), while their performance on the remaining 17 questions is best characterized as a loss of approximately 50% of the material learned in the freshman course. On multiple-choice questions covering advanced physics concepts, the mean score of the participants was about 50% lower than the average performance of freshmen. Although attitudinal survey results indicate that almost half the seniors feel the specific mechanics course content is unlikely to be useful to them, a significant majority (75%--85%) feel that physics does teach valuable problem solving skills, and an overwhelming majority believe that mechanics should remain a required course at MIT.
The First Experimental Test of the Hypothesis that Enzymes Have Evolved To Enhance Hydrogen Tunneling

The literature hypothesis that "the optimization of enzyme catalysis may entail the evolutionary implementation of chemical strategies that increase the probability of quantum-mechanical tunneling" is experimentally tested herein for the first time. The system employed is the key to being able to provide this first experimental test of the "enhanced hydrogen tunneling" hypothesis, one that requires a comparison of the three criteria diagnostic of tunneling (vide infra) for the same, or nearly the same, reaction with and without the enzyme. Specifically, studied herein are the adenosylcobalamin (AdoCbl, also known as coenzyme B(12))-dependent diol dehydratase model reactions of (i). H(D)(*) atom abstraction from ethylene glycol-d(0) and ethylene glycol-d(4) solvent by 5'-deoxyadenosyl radical (Ado(*)) and (ii.) the same H(*) abstraction reactions by the 8-methoxy-5'-deoxyadenosyl radical (8-MeOAdo(*)). The Ado(*) and 8-MeOAdo(*) radicals are generated by Co-C thermolysis of their respective precursors, AdoCbl and 8-MeOAdoCbl. Deuterium kinetic isotope effects (KIEs) of the H(*)(D(*)) abstraction reactions from ethylene glycol have been measured over a temperature range of 80-120 degrees C: KIE = 12.4 +/- 1.1 at 80 degrees C for Ado(*) and KIE = 12.5 +/- 0.9 at 80 degrees C for 8-MeOAdo(*) (values ca. 2-fold that of the predicted maximum primary times secondary ground-state zero-point energy (GS-ZPE) KIE of 6.4 at 80 degrees C). From the temperature dependence of the KIEs, zero-point activation energy differences ([E(D) - E(H)]) of 3.0 +/- 0.3 kcal mol(-)(1) for Ado(*) and 2.1 +/- 0.6 kcal mol(-)(1) for 8-MeOAdo(*) have been obtained, both of which are significantly larger than the nontunneling, zero-point energy only maximum of 1.2 kcal mol(-)(1). Pre-exponential factor ratios (A(H)/A(D)) of 0.16 +/- 0.07 for Ado(*) and 0.5 +/- 0.4 for 8-MeOAdo(*) are observed, both of which are significantly less than the 0.7 minimum for nontunneling behavior. The data provide strong evidence for the expected quantum mechanical tunneling in the Ado(*) and 8-MeOAdo(*)-mediated H(*) abstraction reactions from ethylene glycol. More importantly, a comparison of these enzyme-free tunneling data to the same KIE, (E(D) - E(H)) and A(H)/A(D) data for a closely related, Ado(*)-mediated H(*) abstraction reaction from a primary CH(3)- group in AdoCbl-dependent methylmalonyl-CoA mutase shows the enzymic and enzyme-free data sets are identical within experimental error. The Occam's Razor conclusion is that at least this adenosylcobalamin-dependent enzyme has not evolved to enhance quantum mechanical tunneling, at least within the present error bars. Instead, this B(12)-dependent enzyme simply exploits the identical level of quantum mechanical tunneling that is available in the enzyme-free, solution-based H(*) abstraction reaction. The results also require a similar, if not identical, barrier width and height within experimental error for the H(*) abstraction both within, and outside of, the enzyme.
Effect of dinitrophenol on bladder metabolism and contraction

Urinary bladder function is dependent on the utilization of intracellular metabolic energy. Although preformed ATP is generally regarded to be the major source of metabolic energy for smooth muscle contraction, recent evidence suggests that other sources of metabolic energy may be involved in bladder function. In order to study the relationship between bladder contraction and intracellular ATP, we characterized the effect of 2,4 dinitrophenol (DNP) on rabbit urinary bladder adenine nucleotide metabolsim, intracellular ATP concentration, and isolated bladder strip contraction. DNP specifically inhibits mitochondrial formation of ATP by “uncoupling” mitochondrial oxidation from the phosphorylation of adenine nucleotides. The results can be summarized as follows: (1) DNP produced a dose-dependent inhibition of ATP synthesis. (2) DNP (250 μM) produced a similar gradual decrease (with respect to time) in both contractile response to field stimulation and intracellular ATP concentration. (3) DNP (30-2,000 μM) produced a similar graded dose-dependent decrease in both contractile response to field stimulation and intracellular concentration of ATP. The effect of DNP on bethanechol stimulation of bladder strip contraction was similar to its effect on field stimulation. The inhibitory effect of DNP on the contractile response to both electrical stimulation and bethanechol appears to be directly related to the progressive decline in the contraction of intercellular adenine nucleotides and the decline of adenine nucleotide synthesis.
Crystallization of corticosteroid binding globulin (CBG) and α1acid glycoprotein (AAG)

Abstract The crystallization of two steroid binding proteins CBG and AAG is described as a prelude to three dimensional structure analysis by X-ray diffraction techniques.
Memory-efficient decoding of LDPC codes

We present a low-complexity quantization scheme for the implementation of regular (3,6) LDPC codes. The quantization parameters are optimized to maximize the mutual information between the source and the quantized messages. Using this non-uniform quantized belief propagation algorithm, we have simulated that an optimized 3-bit quantizer operates with 0.2 dB implementation loss relative to a floating point decoder, and an optimized 4-bit quantizer operates less than 0.1 dB quantization loss
Improvement of wood properties by impregnation with multifunctional monomers

Southern pine samples with different dimensions and bulk densities were impregnated with the multifunctional monomer ethyl α-hydroxymethylacrylate (EHMA) and 5 mol % of fluorinated or nonfluorinated crosslinking agent. The maximum impregnation yield (105% by weight) was achieved under vacuum with good improvement of water repellency. Impregnation with EHMA plus another multifunctional monomer 2-vinyl-4,4-dimethyl-2-oxazolin-5-one (vinyl azlactone) was carried out to improve the mechanical properties of wood samples. Water repellency was also improved depending on the amount of vinyl azlactone in the monomer solution. A maximum of 41% antiswell efficiency (ASE) was obtained by impregnation with a 9 : 1 w/w mixture of EHMA and vinyl azlactone. Improvements of 38–54% in impact strength and 27–44% in compression modulus were achieved depending on the relative amount of vinyl azlactone incorporated. FT-IR and solution or solid-state NMR spectroscopy were used for chemical characterization of the polymers themselves and the wood-polymer composites.
The pressure dependence of the austenite start temperature in iron-nickel base alloys

Abstract The effect of hydrostatic pressure up to 20 kbar on the austenite start temperature, As of an Fe-30.3 wt.% Ni alloy has been measured in detail. An exceptionally large pressure coefficient of ≥ 30°C/kbar is observed up to 2.3 kbar; from 2.3 to 6 kbar As is observed to increase with pressure, while from C to 20 kbar As is observed to decrease at a rate of −1.9°C/kbar. A model based on the difference in compressibilities of the martensite and austenite phases is proposed to explain these results. Cold working by rolling prior to the application of hydrostatic pressure shifts the general features of the non-cold worked As vs pressure curve to higher pressure and to higher temperature. It is argued that these observations give very strong evidence that martensite reversal initiates at the martensite-austenite interface. Similar studies were also made on Fe-29.1 wt.% Ni-1 wt.% Co and Fe-30.4 wt.% Xi-2 wt.°% Mn ternary alloys. These results indicate that the character of the martensite reversal (athermal vs. isothermal) may affect the dependence of As on hydrostatic pressure.
Radius of the Vela pulsar

Lasker (1976) has proposed to identify a B roughly equals 23.7 mag star as thermal radiation from the hot neutron star associated with the Vela pulsar. It is shown that this identification, if correct, together with existing X-ray surveys of the Vela supernova remnant, requires that the radius of this pulsar certainly exceed 45 km, and probably 95 km.
RESIDUAL GAS VOLUME EFFECT ON QUALITY OF RETORT POUCH WET-PACK PEARS

Wet pack pears in retort pouches were studied for six months. Four selected residual gas volumes [10, 15, 20 and 30 cubic centimeters (cc)] were used to determine the influence of residual gas volume on physicochemical and sensory attributes. Three storage temperatures (4.4, 26. 7and 37. 8C) were used to carry out an accelerated shew-life study. Residual gas of 30 cc promoted faster darkening and higher ascorbic acid degradation than the rest of the volumes studied (a ≤ 0.01). No significant effect of residual gas volume was found on any other attribute analyzed. Temperature accelerated the consumption of remaining oxygen in the pouches, degradation of ascorbic acid, formation of 5-hydroxymethyl-2-furaldehyde (HMF) and 2-furaldehyde, and softening of pears. Calculated activation energies (EJ for HMF and 2-furaldehyde formation, ascorbic acid, and color degradation were 35, 31.1, 29.8, and 10.4 kcal/mol, respectively. Residual gas volume of 20 cc was the maximum volume studied that accomplished the desired shelf-life for this product.
Soret Spectral and Bioinformatic Approaches Provide Evidence for a Critical Role of the α -Subunit in Assembly of Tetrameric Hemoglobin

Soret spectral contributions of the α-subunit heme pocket have been evaluated by performing static titrations of apohemoglobin A with CNProtohemin under varied experimental conditions. Increasing the temperature from 5 to 30°C in 0.05 M potassium phosphate buffer, pH 7, resulted in a decreasingly prominent hypsochromic shifts reflecting altered the vinyl–globin interactions. Studies at 10°C in over pH range of 6.7–8.0 revealed a profile for the spectral shifts approximating the side chain pK value (7.4) a histidyl residue. These overall spectral changes correspond to ΔE of ≤7 kJ/mol indicative of electrostatic noncovalent interactions. Further our current molecular modeling studies indicate that the spatial arrangement and critical noncovalent interactions of tyrosine 42 and histidine 45 (aromatic residues unique to the α-subunit) make significant contribution to the Soret spectra. Most interestingly, phylogenetic analyses have revealed the presence of a histidyl triad in the α-chain of all vertebrates that form heterotetramers.
Multitarget Tracking With An Optical Neural Net Using A Quadratic Energy Function

Multitarget tracking over consecutive pairs of time frames is accomplished with a neural net. This involves position and velocity measurements of the targets and a quadratic neural energy function. Simulation data are presented, and an optical implementation is discussed.
Adaptation to oak and other fibrous, phenolic-rich foliage by a small mammal, Neotoma fuscipes

Neotoma fuscipes, a small mammalian herbivore with apparently generalized food habits, was laboratory tested to determine its degree of dietary specialization. Woodrats from both oak woodland and coastal sage communities preferred Quercus agrifolia leaves (containing 40% phenolics and about 16% condensed tannin) over foliage from other dominant species. Approximately one-third of the oak phenolics and less than 10% of the oak condensed tannin remained in the feces. Their performance on pure oak leaves was comparable to that on a mixed diet of Quercus, Salvia, Eriogonum, and Rhus, with respect to weight maintenance, digestive efficiency and total amount ingested. Digestive efficiency was low on the oak diet (55%) relative to Salvia (77%), and to achieve similar weight levels, approximately twice as much oak as Salvia was ingested. Woodrats retained more nitrogen as oak consumption increased. Intake of oak and other foods increased with each experimental day. A sympatric species, N. lepida, was unable to maintain weight on oak leaves, although its digestive and polyphenolic-degrading capabilities, and nitrogen retention efficiency were equivalent to those of N. fuscipes. On a weight-adjusted basis, N. lepida ate about half as much oak per day as N. fuscipes. Oak intake may have been reduced by an inability to rapidly degrade fiber, which constitutes about 30% of the oak diet. In natural populations, N. fuscipes selectively feeds on evergreen sclerophyll vegetation high in fiber, tannins and related polyphenolics. Individuals ingest 2–3 plant types at a time, with a single species (oak when available) constituting most of the material consumed. Neotoma lepida diets are also dominated by a single species. The diversity of plant types eaten by different populations of N. lepida suggests that local dietary specializations may be developmentally acquired.
Flow field in a shrinking-bed reactor for pretreatment of cellulosic biomass.

A shrinking-bed reactor was designed by the National Renewable Energy Laboratory to maintain a constant bulk packing density of cellulosic biomass. The high solid-to-liquid ratio in the pretreatment process allows a high sugar yield and avoids the need to flush large volumes of solution through the reactor. The shrinking-bed reactor is a promising pretreatment reactor with the potential for scale-up for commercial applications. To scale up the shrinking-bed reactor, it is necessary to understand the flow pattern in the reactor. In this study, flow field is simulated with computational fluid dynamics using a porous medium model. Different discrete “snapshots” and multiple steady states are utilized. The bulk flow pattern, velocity distribution, and pressure drop are determined from the simulation and can be used to guide reactor design and scale-up.
The role of video game playing in adolescent life: Is there reason to be concerned?

One hundred fifty-one subjects from 10 to 20 years old were surveyed to determine their attitudes toward video game playing and its role in their lives. Concerns have been expressed in the public media that video game playing is addictive for youngsters and leads to excessive expenditures of time and money, poorer school performance, reduced involvement in sports, and less opportunity to develop social skills. The survey data did not support these contentions. Although approximately 10% of the subjects appeared to show some compulsive aspects in their play, no identifiable problems were correlated with the amount of time spent playing. For the great majority, video game playing was an enjoyable activity held in perspective with other aspects of their lives.
12(R)-hydroxyeicosatrienoic acid, a potent chemotactic and angiogenic factor produced by the cornea

Human and bovine corneal epithelial cytochrome P450 convert arachidonic acid to compound D [12(R)-hydroxy-5,8,14(Z,Z,Z)-eicosatrienoic acid], a metabolite with inflammatory properties including vasodilatation and breakdown of the blood-aqueous barrier. Angiogenic properties of the endogenous compound D and the synthetic enantiomers DR and DS were examined using the corneal micropocket technique. The synthetic compound DR was as active as the endogenously formed compound D. Neovascularization of the cornea was found in all the implants containing as little as 0.5 micrograms of compound DR. In contrast, the stereoisomer DS at the same concentration (0.5 micrograms) was inactive. Since angiogenesis can be secondary to a local inflammatory response, we evaluated the effects of compound DR and its stereoisomer DS on human neutrophil chemotaxis by using a modified Boyden chamber technique. DR, but not DS, was found to be a potent chemotactic factor, exhibiting dose-dependent neutrophil chemotaxis with significant responses observed at doses as low as 10(-11) M, a concentration at which leukotriene B4 does not exhibit significant chemotactic activity. Therefore, compound D produced by the cornea may qualify as an intrinsic corneal angiogenic factor which, in association with other inflammatory mechanisms, account for the growth of new vessels in the cornea that appear in chronic inflammation or in the reparative stages of an acute process.
Low-dimensional electron gas at semiconductor surfaces

In recent years, it has become possible to create well-ordered semiconductor surfaces with metallic surface states by using self-assembly of metal atoms. Since these states lie in the band gap of the semiconductor, they completely decouple from the substrate. In addition to two-dimensional structures it is possible to obtain arrays of one-dimensional atomic chains, which may be viewed as the ultimate nanowires. The dimensionality can be varied systematically by using vicinal surfaces with variable step spacing. Angle-resolved photoemission and scanning tunnelling spectroscopy reveal surprising features, such as a fractional band filling, nanoscale phase separation into doped and undoped chain segments, and a spin-splitting at a non-magnetic surface. Prospects for one-dimensional electron gas physics in atomic chains are discussed.
Uranus' Apparent Seasonal Variability in 25 HST Filters☆

Abstract Hubble Space Telescope (HST) images of Uranus taken in 1997 reveal that Voyager's view of the southern hemisphere was not representative of the rest of the planet. The banded structure with hemispherical asymmetry, presented in 25 filters between 0.27 and 2.03 μm wavelength, caused Uranus' full disk to darken by as much as 35% between 1985 and 2001, and probably much more over a full uranian season. The amplitude is strongly wavelength dependent. Hemispherical albedo asymmetries are as large as a factor of two over low latitudes and could be larger when they include higher latitudes that will be observable soon. Previous models of Uranus' atmosphere do not apply to northern latitudes. Some observed brightness variations of Uranus, explained as physical variations in previous studies, can now be fully explained by the geometry of changing subsolar latitudes. HST images taken between 1994 and 2000 show the latitudinal albedo structure and the number of discrete clouds in both hemispheres remaining roughly constant, although a slight darkening of high southern latitudes at some filters probing the methane haze indicates a slow decrease in its optical depth. A similar conclusion applies when including Voyager images of 1986. Physical changes in Uranus' atmosphere were many times faster before 1982 than since, and a similar rapid change can be expected in the near future.
Frequency characteristics of acoustic priming of audiogenic seizures in mice.

Abstract Mice of C57BL 6J strain were acoustically primed at 16 days of age and tested for audiogenic seizures 5 days later. Priming and testing stimuli consisted of 60 sec exposure to one of several pure tones at an intensity of 110 db. Priming at 5 and 7.5 kHz was found to be ineffective. In general, priming increased in effectiveness as a direct function of frequency. The same trend was evident for testing with higher frequencies resulting in more severe audiogenic seizures. In addition, some evidence was presented for both frequency specificity and generalization of acoustic priming.
The origin of relative intensity fluctuations in single-molecule tip-enhanced Raman spectroscopy.

An explanation of the relative intensity fluctuations observed in single-molecule Raman experiments is described utilizing both single-molecule tip-enhanced Raman spectroscopy and time-dependent density functional theory calculations. No correlation is observed in mode to mode intensity fluctuations indicating that the changes in mode intensities are completely independent. Theoretical calculations provide convincing evidence that the fluctuations are not the result of diffusion, orientation, or local electromagnetic field gradients but rather are the result of subtle variations of the excited-state lifetime, energy, and geometry of the molecule. These variations in the excited-state properties will provide information on adsorbate–adsorbate and adsorbate–substrate interactions and may allow for inversion of experimental results to obtain these excited-state properties.
ESTABLISHMENT AND CHARACTERIZATION OF ADENOSINE DEAMINASE (ADA)-DEFICIENT T CELL LINES

Congenital deficiency of the purine metabolic enzyme ADA causes severe combined immunodeficiency (SCID). The profound T lymphopenia characteristic of this disease has limited direct investigation of the cell most affected by deficiency of ADA. We have been successful in establishing both IL-2-dependent, non-transformed and HTLV-1 transformed T cell lines from eight consecutive ADA-deficient SCID patients. The lines obtained by either method are mature T cells by surface phenotype. These lines all display hypersensitivity to deoxyadenosine, characteristic of ADA deficiency, which is not reversed by deoxycytidine. Clones obtained by limiting dilution of one line show multiple unique rearrangeents of the T cell receptor beta gene suggesting clonal diversity among the circulating T cells of this patient, despite lymphopenia and SCID. Lines from 5 patients, all under three years old, have less than 1% normal ADA activity. Pharmacologic inhibitor studies suggest that this remaining activity is attributable to a non-specific aminohydrolase. In contrast, cells from two children ages 11 and 13 years are partially deficient with up to 10% normal ADA activity. An eighth SCID patient, previously found to totally lack erythrocyte ADA has approximately 50% normal ADA in a line derived from thymocytes. Analysis of the molecular basis for ADA deficiency in these lines shows that the majority have a grossly intact ADA gene, contain normal size ADA mRNA (1.6kb) and produce an ADA protein that is catalytically defective.
A novel biliverdin with an inverted pyrrole subunit

Abstract The synthesis and spectroscopic properties of a novel biliverdin 4 with one inverted pyrrole ring are described; the dipyrromethane 8 and a,c-biladiene 6 were the key intermediates in the synthesis of 4 .
Shareholder Wealth Effects of CEO Succession

Companies often dismiss their chief executive officers (CEOs) when financial performance falters. This study examines why, despite the positive stock market effects, the replacement of the CEO often does little to change a company’s financial performance. Thanks to the agency arrangements in some companies, new CEOs are able to negotiate favorable contracts which benefit the CEO rather than the shareholders. In a sample of 140 publicly-traded firms, we found that compensation systems for new CEOs differed as a function of institutional ownership, with total executive compensation higher and compensation risk lower in firms with lower levels of institutional ownership. Financial performance was also weaker in firms with less institutional ownership.