cssi/SciSciGPT-SciSciNet huggingface dataset:
Upper Gastrointestinal Hemorrhage (and Portal Hypertension)

During my residency in the 1980s, not a week passed without a few operations for bleeding duodenal (DU) or gastric (GU) ulcers. Emergency gastrectomies, antrectomies, truncal vagotomies, and highly selective vagotomies were our daily bread and butter. But, gradually things started to change. First appeared the H2 antagonists, followed by proton pump inhibitors (PPIs), and then anti-Helicobacter therapy. In addition, novel methods of achieving transendoscopic hemostasis of bleeding ulcers emerged. As a result, at least where we practice, operations for upper gastrointestinal hemorrhage (UGI-H) have become a rarity, and our approach to them has been modified. However, if you work somewhere in the so-called developing world, where modern antiulcer medications are not freely available, you may be exposed still to the old pattern of peptic ulcer disease and the traditional methods of dealing with it.
Out of the House of Bondage: The Transformation of the Plantation Household

1. The gender of violence 2. 'Beyond the limits of decency': women in slavery 3. Making 'better girls': Southern women and the claims of domesticity 4. 'Nothing but deception in them': the war within 5. Out of the house of bondage: a sundering of ties, 1865-6 6. 'A makeshift kind of life': free women and free homes 7. 'Wild notions of right and wrong': from home to the streets.
Further analysis of the lens of ephrin-A5−/− mice: development of postnatal defects

Purpose The cells of the mammalian lens must be carefully organized and regulated to maintain clarity. Recent studies have identified the Eph receptor ligand ephrin-A5 as a major contributor to lens development, as mice lacking ephrin-A5 develop abnormal lenses, resulting in cataracts. As a follow-up to our previous study on the cataracts observed in ephrin-A5−/− animals, we have further examined the morphological and molecular changes in the ephrin-A5−/− lens.
Die cracking in flip-chip-on-board assembly

The die cracking in a flip-chip-on-board (FCOB) assembly occurs very often during the solder reflow process and the fracture path follows a straight downward crack extension and then kinks at a certain depth. Such a fracture path selection in FCOB structures is determined here based on a mode-I domination criterion. This is done by solving the corresponding problem of a kinked crack in a FCOB structure for a series of kinking angles. The numerical results indicate that the energy release rate maximum assumes initially at a zero-degree angle, which points to the straight downward extension in the thickness direction, and then shifts to a large angle, which corresponds to kinking. The kinking angle and the depth at which the kink starts have been predicted and compared agreeably with cross sectioning of failed samples from a manufacturing floor. The maximum allowable manufacturing defect size, below which the die cracking can be prevented, is then determined by a beam theory. The analysis suggests that in a typical FCOB structure a defect size of more than 35 micron will result in die cracking failure after solder reflow. The numerical results also reveal that a good tolerance of defects can be achieved by limiting the board thickness to be less than twice of the die.
Proteomics: Analysis of Spectral Data

The goal of disease-related proteogenomic research is a complete description of the unfolding of the disease process from its origin to its cure. With a properly selected patient cohort and correctly collected, processed, analyzed data, large scale proteomic spectra may be able to provide much of the information necessary for achieving this goal. Protein spectra, which are one way of representing protein expression, can be extremely useful clinically since they can be generated from blood rather than from diseased tissue. At the same time, the analysis of circulating proteins in blood presents unique challenges because of their heterogeneity, blood contains a large number of different abundance proteins generated by tissues throughout the body. Another challenge is that protein spectra are massively parallel information. One can choose to perform top-down analysis, where the entire spectra is examined and candidate peaks are selected for further assessment. Or one can choose a bottom-up analysis, where, via hypothesis testing, individual proteins are identified in the spectra and related to the disease process. Each approach has advantages and disadvantages that must be understood if protein spectral data are to be properly analyzed. With either approach, several levels of information must be integrated into a predictive model. This model will allow us to detect disease and it will allow us to discover therapeutic interventions that reduce the risk of disease in at-risk individuals and effectively treat newly diagnosed disease.
Bis(N‐propylsalicylideneaminato)copper(II)

[14077-15-7] C20H24CuN2O2 (MW 387.97) InChI = 1S/2C10H13NO.Cu/c2*1-2-7-11-8-9-5-3-4-6-10(9)12;/h2*3-6,8,12H,2,7H2,1H3;/q;;+2/p-2/b2*11-8+; InChIKey = GZGCPTHCHJCERY-VEAPMNRTSA-L (catalyzes decomposition of diazo ketones to carbenoids;2 promotes electron transfer reactions4) Alternate Name: bis[2-(N-propylformimidoyl)phenolato]copper. Physical Data: green or greenish-brown needles; mp 127–128 °C. Solubility: sol alcohol, dioxane, chloroform, and benzene; insol water, pet ether. Preparative Method: by one-pot reaction of n-propylamine with the bis(salicylaldehato)copper complex prepared from copper(II) acetate and salicylaldehyde.1 Purification: recrystallization from cyclohexane or chloroform–ethanol.1 Handling, Storage, and Precautions: irritant. The copper chelate can be stored at rt in the absence of moisture.
The Effect of Material A's Cytotoxity to A549, 293T, HEP3B Cells

There are many materials around us that we don't know what this would do for us. We selected material A(Oligosaccaride) from the nature and planed the experiment that we can know how it affects the cells. For this study, we cultured two cancer cell lines(HEP3B, A549) and one immortalized cell line(293T) and planted the cells on a plate of 96 wells. After making the material A diluted in 2%, 1% and 0.5% by adding RPMI 1640, we incubated the cells with diluted material A solutions for 24 hours and conducted MTT assay for detecting cell viability. In case of HEP3B cell, the viabilities in 2%, 1%, and 0.5% solutions were 106%, 95%, 59%. The viabilities of A549 in 2%, 1%, 0.5% solutions were 106%, 86% and 57%. The survival rates of 293T in 2%, 1%, 0.5% solutions were 30%, 40%, 45%. In this result, we could find that the viabilities of two cancer cells decrease as the concentration of diluted material A gets higher but these of 293T are very low and alike regardless of concentrations of material A. we concluded that 293T is much more susceptible to the cytotoxicity of material A than two cancer cells.
Medical Students Pursuing Surgical Fields Have No Greater Innate Motor Dexterity than Those Pursuing Nonsurgical Fields

Introduction Medical students pursue different career paths based on a variety of factors. We sought to examine the impact of innate manual dexterity, both perceived and objective, on the career interests of medical students. Methods Third-year medical students from the University of California, Irvine were recruited for this study. Subjects completed a pretest questionnaire followed by assessment of gross and fine motor dexterity using the Purdue Pegboard test. A total of 6 independent trials were performed, 3 for each hand. The scores were recorded as an integer value between 0 and 25. A statistical analysis was performed using student t tests, the Fischer exact test, or the χ2 test, where appropriate. Results A total of 100 students completed the questionnaire while 58 completed the dexterity testing. Students interested in a surgical field (SF) were similar in handedness, gender, video game exposure, and learning style as those interested in a nonsurgical field (NSF). In the SF group, “personal skill set” was reported as the most common factor influencing career selection, and “interest in disease process/patient population” was reported most commonly by NSF students (p = 0.015). Although a perceived innate manual dexterity was higher among SF students compared with NSF students (p = 0.032), no significant objective differences were found in right hand, left hand, or combined dexterity scores. Conclusions Perceived “personal skill set” may influence strongly a medical student's career choice. Despite greater perceived manual dexterity, students interested in an SF do not have greater objective innate manual dexterity than those interested in an NSF.
Real-Time Analysis of Individual Atmospheric Aerosol Particles: Design and Performance of a Portable ATOFMS

Two portable aerosol time-of-flight mass spectrometers (ATOFMS) of identical design are described. These instruments are powerful new tools for providing temporal and spatial information on the origin, reactivity, and fate of atmospheric aerosols. Each is capable of analyzing the size and composition of individual particles from a polydisperse aerosol in real-time. Particles are introduced into the instrument through a particle beam interface, sized by measuring the delay time between two scattering lasers, and compositionally analyzed using a dual-polarity laser desorption/ionization time-of-flight mass spectrometer. These are the first dual-ion TOFMS instruments to utilize a dual reflectron design. The instruments measure 72 in. long × 28 in. wide × 60 in. high and weigh ∼500 lb. Pneumatic tires allow them to be transported through standard doorways, elevators, and handicap ramps, granting access to virtually any location. Furthermore, because of rugged construction they will be able to operate during t...
Mechanisms of Zr(IV) and La (III) catalysis of the reduction of nitrate at mercury

Cyclic voltammetry, phase selective ac polarography, and conductance measurements were used to demonstrate that Zr(IV) catalysis of the reduction of nitrate at mercury electrodes occur because of electrostatic interaction of the nitrate with adsorbed Zr(IV). The overall process is an 8-electron reduction to ammonia. That the adsorption of Zr(IV) is required mechanistic step causes breaks in voltammetric mole ratio plots which are related to the surface excess of the catalyst rather than the stoichiometry of a complex in the bulk solution. The surface excess and, therefore, the mole ratio plot inflection points are dependent upon pH. Addition of proton increases the range over which the current is proportional to nitrate concentration. La(III) was found to catalyze the nitrate reduction by the same general mechanism.
Selective expression of clusterin (SGP-2) and complement C1qB and C4 during responses to neurotoxinsin vivo andin vitro

Abstract This study concerns expression of the genes encoding three multifunctional proteins: clusterin and two complement cascade components, C1q and C4. Previous work from this and other laboratories has established that clusterin, Clq and C4 messenger RNAs are elevated during Alzheimer's disease, and in response to deafferenting and excitotoxic brain lesions. This study addresses hippocampal clusterin, ClqB and C4 expression in response to neurotoxins that caused selective neuron death. Kainate, which preferentially kills hippocampal CA3 pyramidal neurons but not dentate gyrus granule neurons induced clusterin immunoreactivity in CA1 and CA3 pyramidal neurons and adjacent astrocytes, but not in dentate gyrus granule neurons. In contrast, colchicine, which preferentially kills the dentate gyrus granule neurons, induced clusterin immunoreactivity in the local neuropil as punctate deposits, but not in the surviving or degenerating dentate gyrus granule neurons. Clusterin messenger RNA was increased in astrocytes. C1qB and C4 messenger RNAs increased within 48 h after kainate injections, particularly in the CA3 pyramidal layer, less in the dentate gyrus-CA4, and less in CA1. C1q immunoreactivity was detected in CA1 pyramidal neurons and also as small punctate deposits in the CA1 region at eight and 14 days after kainate. The increase of both clusterin and C1qB messenger RNAs after kainate injections was blocked by barbiturates that prevented seizures and neurodegeneration. In primary hippocampal neuronal cultures treated with glutamate, a subpopulation of cultured neurons that survived glutamate toxicity also had parallel elevations of clusterin and C1qB messenger RNA. In conclusion, cytotoxins that target selective hippocampal neurons increase the expression of both clusterin and C1qB in vivo and in vitro . These results show that elevations of clusterin messenger RNA or protein can be dissociated from each other and from cell death. These increased messenger RNAs were associated with immunoreactive deposits that differed by cell type and intra- versus extracellular locations. These results suggest that the complement system is involved in brain responses to injury.
Spectra and structure of silicon containing compounds. XLI. Infrared and Raman spectra, conformational stability, vibrational assignment and ab initio calculations of cyclopropylbromosilane☆

Abstract The infrared (3100–40 cm −1 ) spectra of gaseous and solid and Raman (3200–100 cm −1 ) spectra of liquid cyclopropylbromosilane, c -C 3 H 5 SiH 2 Br, have been recorded. Both the cis and gauche conformers have been identified in the fluid phases but only the gauche conformer remains in the solid. Variable temperature (−105 to −150 °C) studies of the infrared spectra of the sample dissolved in liquid krypton have been recorded and the enthalpy difference has been determined to be 126±25 cm −1 (1.50±0.30 kJ/mol) but with the cis conformer the more stable form in the rare gas solution. At ambient temperature it is estimated that there is 52±2% of the gauche conformer present. Relatively complete vibrational assignments are proposed for both conformers based on the relative infrared and Raman spectral intensities, infrared band contours, and ab initio predicted frequencies. The geometrical parameters, harmonic force constants, vibrational frequencies, infrared intensities, Raman activities, depolarization ratios, and energy differences have been obtained for the cis and gauche conformers from ab initio MP2/631G(d) calculations. Structural parameters and energy differences have also been obtained utilizing the larger 6-311+G(d,p) and 6-311+G(2d,2p) basis sets as well as these bases sets without diffuse functions. The predicted conformer stability and energy differences from these calculations agree with the experimentally determined stability and enthalpy difference except for the calculations at the Hartree–Fock level. Similar calculations by density functional theory (DFT) by the B3LYP method with eight different basis sets up to 6-311+G(2d,2p) gave incorrect conformer stabilities with the gauche conformer more stable by approximately 130 cm −1 from all calculations. Similar DFT calculations for cyclopropylchlorosilane also give incorrect predicted conformational stabilities. The results are discussed and compared to those obtained for some similar molecules.
Protein structural modularity and robustness are associated with evolvability

Theory suggests that biological modularity and robustness allow for maintenance of fitness under mutational change, and when this change is adaptive, for evolvability. Empirical demonstrations that these traits promote evolvability in nature remain scant however. This is in part because modularity, robustness, and evolvability are difficult to define and measure in real biological systems. Here, we address whether structural modularity and/or robustness confer evolvability at the level of proteins by looking for associations between indices of protein structural modularity, structural robustness, and evolvability. We propose a novel index for protein structural modularity: the number of regular secondary structure elements (helices and strands) divided by the number of residues in the structure. We index protein evolvability as the proportion of sites with evidence of being under positive selection multiplied by the average rate of adaptive evolution at these sites, and we measure this as an average over a phylogeny of 25 mammalian species. We use contact density as an index of protein designability, and thus, structural robustness. We find that protein evolvability is positively associated with structural modularity as well as structural robustness and that the effect of structural modularity on evolvability is independent of the structural robustness index. We interpret these associations to be the result of reduced constraints on amino acid substitutions in highly modular and robust protein structures, which results in faster adaptation through natural selection.
STATs and cytokine specificity

Several STATs transduce signals and activate genes only in response to select cytokines—will all STATs prove so specific?
The End of Hospital Cost Shifting and the Quest for Hospital Productivity

Although perennially relevant, investigation of the effect of Medicare hospital payment changes on hospital and health system performance has heightened salience today. The 2010 Patient Protection and Affordable Care Act (Public Law 111–148; hereafter, ACA) will permanently reduce the Medicare payments hospitals would otherwise receive. Its “productivity adjustment” will scale payments downward by the average rate at which private nonfarm businesses’ productivity increases. That rate has been estimated to be 1.1 percentage points per year (Shatto and Clemens 2011), larger than historical, annual hospital productivity gains (Cylus and Dickensheets 2007–2008). Unless hospitals become more productive, they will have to find other ways to handle lower growth in Medicare payments. How will the industry respond?
An inventory model with partial backordering and unit backorder cost linearly increasing with the waiting time

As the implementation of JIT practice becomes increasingly popular, each echelon in a supply chain tends to carry fewer inventories, and thus the whole supply chain is made more vulnerable to lost sales and/or backorders. The purpose of this paper is to recast the inventory model to be more relevant to current situations, where the penalty cost for a shortage occurrence at a downstream stage in a supply chain is continually transmitted to the upstream stages. The supplier, in this case, at the upstream of the supply chain is responsible for all the downstream shortages due to the chain reaction of its backlog. The current paper proposes a model in which the backorder cost per unit time is a linearly increasing function of shortage time, and it claims that the optimal policy for the supplier is setting the optimal shortage time per inventory cycle to minimize its total relevant cost in a JIT environment.
Phosphorylation of CAP-G is required for its chromosomal DNA localization during mitosis

Condensin is a 5 subunit complex that plays an important role in the structure of chromosomes during mitosis. It is known that phosphorylation of condensin subunits by cdc2/cyclin B at the beginning of mitosis is important for condensin activity, but the sites of these phosphorylation events have not been identified nor has their role in regulating condensin function. Here we identify two threonine residues in the CAP-G subunit of condensin, threonines 308 and 332, that are targets of cdc2/cyclin B phosphorylation. Mutation of these threonines to alanines results in defects in CAP-G localization with chromosomes during mitosis. These results are the first to identify phosphorylation sites within the condensin complex that regulate condensin localization with chromosomal DNA.
The Impact of Providing Web-Based Powerpoint Slides as Study Guides in Undergraduate Business Classes

This study examines undergraduate business students' use of PowerPoint slides provided as a supplement to class attendance, textbook reading, and other traditional course resources. We survey students in 4 diverse (accounting, marketing, management, and information systems) lower-level undergraduate courses in which the instructor provided PowerPoint slides in addition to traditional course lectures and materials for student use. The effects of students' learning strategies were measured against class attendance, test performance, and overall course performance. Results indicate that there is little relationship between use of these resources and grades on exams or overall course grades, consistent with several prior studies. Further, we find that students do not view these supplemental on-line resources as a substitute for class attendance.
Improving detection by pediatric residents of endotracheal tube dislodgement with capnography: a randomized controlled trial.

Objective The authors sought to determine if capnography could improve time to correction of a simulated endotracheal tube (ETT) dislodgement by pediatric residents. Study design Pediatric residents attended a didactic session that included interpretation of capnography. A randomized controlled study was then performed using patient simulators. Residents were randomized to standard monitoring (control group) or standard monitoring plus capnography (intervention group). The primary outcome was time to correction of ETT dislodgement. Correction of dislodgement prior to decline in pulse oximetry was our secondary outcome. Results Twenty-seven subjects completed the simulation. Subjects in the intervention group corrected the ETT dislodgement faster than those in the control group (2.38 minutes vs 3.92 minutes, P = .02). There were no differences in time to correction based on postgraduate year, clinical experiences, or comfort with capnography. Two subjects corrected the dislodgement prior to changes in pulse oximetry, both from the intervention group. Fifty-nine percent of subjects had seen capnography used in the past and 82% felt very or somewhat comfortable with capnography. Conclusion Capnography decreased time to correction of ETT dislodgement by pediatric residents. Capnography should be considered as an essential monitoring device for intubated patients to enhance patient safety.
Four naturally occurring mutations in the human GnRH receptor affect ligand binding and receptor function

Abstract In the present study, we performed functional analyses of four mutations in the human GnRH receptor (GnRHR) gene, identified in patients with idiopathic hypogonadotropic hypogonadism. These mutations result in amino acid substitutions in the extracellular N-terminal domain (Thr32Ile), second extracellular loop (Cys200Tyr), third intracellular loop (Leu266Arg) and sixth transmembrane helix (Cys279Tyr). Immunocytochemical analysis of cells transfected with HA-tagged GnRHR constructs revealed that all four mutant receptors were present on the cell surface. However, all four mutant receptors failed to exhibit measurable specific GnRH binding and, except for Thr32Ile, any significant inositol phosphate accumulation after GnRH stimulation. In addition, Leu266Arg and Cys279Tyr receptors were unable to stimulate gonadotropin subunit or GnRHR gene promoter activity in response to GnRH. Interestingly, the Cys200Tyr mutant was able to stimulate gonadotropin subunit and GnRHR promoter activity, albeit with a higher EC50 and a markedly reduced maximal response compared to wild type receptor. The Thr32Ile mutant was also able to stimulate gonadotropin subunit and GnRHR promoters, but with a further significant increase in EC50. Similarly, this mutant partially retained the ability to activate extracellular signal-regulated kinase 1 and stimulate CRE-luciferase activity with an identical shift in EC50. Taken together, the studies suggest that the Thr32Ile mutation reduces hGnRHR function primarily by reducing ligand binding affinity, and the Cys200Tyr mutation reduces cell surface receptor expression. All four amino acid substitutions interfered with ligand binding, and affected signal transduction and stimulation of gonadotropin and GnRHR gene expression in response to GnRH.
Use of Mechanistic-Empirical Pavement Design Principles to Assign Asphalt Pavement Pay Factor Adjustments

AbstractThis paper promotes the quality analysis of flexible pavements by exploring the role of analysis programs as laboratory support tools to assess the quality of constructed pavements. Specifically, the research explored the significance of laboratory dynamic modulus testing on assigning pay factor adjustments in these tools. In the United States, the current methods of pavement acceptance are based more on construction craftsmanship (i.e., density and smoothness, percent within limits) as opposed to how the pavement will actually perform once constructed. The use of performance-based specification models would enable a state transportation agency to quantify the impacts of varying as-built mixture quality in terms of (1) a projection of pavement service life, and (2) presenting life-cycle costs in a way that both agencies and contractors can understand. Two publicly available performance-related specification (PRS) quality assurance (QA) analysis tools have been developed based on mechanistic-empiri...
Diagnosing Strep Throat in the Adult Patient: Do Clinical Criteria Really Suffice?

In this issue, Neuner and colleagues report a cost-effectiveness analysis of the diagnosis and treatment of adults with pharyngitis caused by group A -hemolytic streptococcus. Contrary to a recent ...
Pectic and cellulolytic enzymes in soybeans

Abstract The dominant cell wall degrading enzymes detected in extracts from 6-day-old, dark grown, Lee soybean seedlings carried out random (endo) and hydrolytic cleavages of pectic acid, pectin and methylcellulose. The pH optima of these activities were 6·0, 6·5 and 5·7 respectively. Monogalacturonic acid and another unidentified product accumulated during the degradation of polygalacturonic acid.
On the relationship between the cut-tree and the fundamental cut set of multi-terminal flow networks

We are concerned with undirected flow networks in which any two nodes, generically designated by s and t, can serve as source and terminal, respectively. Let G be any linear network of N notes and A arcs with every arc aEA possessing a finite capacity c(a). Let R be the cut-tree of G obtained by the Gomory-Hu construction (1), and denote its links (which are, in fact, cut sets of G) by ra, r2, • . . , r~l . Let arc a = (i , j)eA be the are joining the two nodes i and j in G. Then we have
The sperm penetration assay: Can it discriminate between s fertile and infertile men?

The sperm penetration assay with zona-free hamster ova is widely used to evaluate male infertility. Despite a growing body of literature about this assay, its results remain difficult to interpret. To evaluate the clinical usefulness of this test, we reviewed the world's literature about this assay and analyzed the test's performance. Its sensitivity ranges from 0.00 to 1.00 and specificity ranges from 0.95 to 1.00 for diagnosing male infertility. For predicting in vitro fertilization failures, its sensitivity varies from 0.00 to 0.78 and specificity ranges from 0.51 to 1.00. The reproducibility of this assay is not clear, and there is little standardization of methods between laboratories. Until the validity and reproducibility of the sperm penetration assay have been established, this expensive test should probably not be used to evaluate infertile couples.
A developmentally regulated neuraminidase activity in Trypanosoma cruzi

The human pathogen Trypanosoma cruzi (Y strain) contains a neuraminidase activity that varies widely in the different developmental stages of the parasite. The specific neuraminidase activity of infective trypomastigotes obtained from tissue culture and from the bloodstream of infected mice is 7 to 15 times higher than that of the acellular culture forms. Amastigotes were devoid of enzyme activity. The enzyme has a pH optimum of 6.0 to 6.5. Live trypanosomes released sialic acid from human erythrocytes and plasma glycoproteins. Several sialyl compounds were hydrolyzed by the parasite, but the best substrate was the protein orosomucoid. Erythrocytes from infected mice with T. cruzi parasitemia were agglutinated by peanut lectin and the hemagglutination titer was correlated with the degree of parasitemia.
Characterizing coarse-resolution watershed soil moisture heterogeneity using fine-scale simulations

Abstract. Watershed-scale hydrological and biogeochemical models are usually discretized at resolutions coarser than where significant heterogeneities in topography, abiotic factors (e.g., soil properties), and biotic (e.g., vegetation) factors exist. Here we report on a method to use fine-scale (220 m grid cells) hydrological model predictions to build reduced-order models of the statistical properties of near-surface soil moisture at coarse resolution (25 times coarser, ~7 km). We applied a watershed-scale hydrological model (PAWS-CLM4) that has been previously tested in several watersheds. Using these simulations, we developed simple, relatively accurate (R2 ~0.7–0.8), reduced-order models for the relationship between mean and higher-order moments of near-surface soil moisture during the nonfrozen periods over five years. When applied to transient predictions, soil moisture variance and skewness were relatively accurately predicted (R2 0.7–0.8), while the kurtosis was less accurately predicted (R2 ~0.5). We also tested 16 system attributes hypothesized to explain the negative relationship between soil moisture mean and variance toward the wetter end of the distribution and found that, in the model, 59% of the variance of this relationship can be explained by the elevation gradient convolved with mean evapotranspiration. We did not find significant relationships between the time rate of change of soil moisture variance and covariances between mean moisture and evapotranspiration, drainage, or soil properties, as has been reported in other modeling studies. As seen in previous observational studies, the predicted soil moisture skewness was predominantly positive and negative in drier and wetter regions, respectively. In individual coarse-resolution grid cells, the transition between positive and negative skewness occurred at a mean soil moisture of ~0.25–0.3. The type of numerical modeling experiments presented here can improve understanding of the causes of soil moisture heterogeneity across scales, and inform the types of observations required to more accurately represent what is often unresolved spatial heterogeneity in regional and global hydrological models.
Phototransduction: Inactivation in Cones

Rapid inactivation of light-induced signaling in rod photoreceptors is crucial for their single-photon sensitivity and sub-second temporal resolution. Every step in the signaling pathway has a dedicated inactivation mechanism. Light-activated rhodopsin is quenched via phosphorylation by rhodopsin kinase, followed by arrestin binding. Transducin is inactivated by its intrinsic GTPase activity, which is greatly accelerated by its effector PDE and RGS9-1. The decrease in cytoplasmic cGMP closes cGMP-gated Na + /Ca 2+ channels, hyper-polarizing the cell. By doing so, it reduces intracellular Ca 2+ . The replacement of Ca 2+ with Mg 2+ on GCAPs activates RetGC, which promptly replenishes cGMP, opening the channels and restoring membrane potential.
Formation of atomic point contacts and molecular junctions with a combined mechanical break junction and electrodeposition method

A method to create atomic point contacts and molecular junctions by combining mechanically controlled break junction and electrochemical deposition/etching techniques is described. This approach provides both stability and flexibility, and is suitable for studying electron transport properties of single molecule junctions or atomic point contacts in aqueous solutions and under potential control. Using the approach, the electron transport properties of 4,4′-bipyridine as a function of electrochemical gate and Ni point contacts have been studied.
Structure of Substrate-free Human Insulin-degrading Enzyme (IDE) and Biophysical Analysis of ATP-induced Conformational Switch of IDE

Insulin-degrading enzyme (IDE) is a zinc metalloprotease that hydrolyzes amyloid-β (Aβ) and insulin, which are peptides associated with Alzheimer disease (AD) and diabetes, respectively. Our previous structural analysis of substrate-bound human 113-kDa IDE reveals that the N- and C-terminal domains of IDE, IDE-N and IDE-C, make substantial contact to form an enclosed catalytic chamber to entrap its substrates. Furthermore, IDE undergoes a switch between the closed and open conformations for catalysis. Here we report a substrate-free IDE structure in its closed conformation, revealing the molecular details of the active conformation of the catalytic site of IDE and new insights as to how the closed conformation of IDE may be kept in its resting, inactive conformation. We also show that Aβ is degraded more efficiently by IDE carrying destabilizing mutations at the interface of IDE-N and IDE-C (D426C and K899C), resulting in an increase in Vmax with only minimal changes to Km. Because ATP is known to activate the ability of IDE to degrade short peptides, we investigated the interaction between ATP and activating mutations. We found that these mutations rendered IDE less sensitive to ATP activation, suggesting that ATP might facilitate the transition from the closed state to the open conformation. Consistent with this notion, we found that ATP induced an increase in hydrodynamic radius, a shift in electrophoretic mobility, and changes in secondary structure. Together, our results highlight the importance of the closed conformation for regulating the activity of IDE and provide new molecular details that will facilitate the development of activators and inhibitors of IDE.
Aluminum and phosphorus separation: application to preparation of target from brain tissue for 26Al determination by accelerator mass spectrometry

Abstract Acid digested brain containing 4 mg added 27 Al was ashed at 1000°C to prepare an Al 2 O 3 target for accelerator mass spectrometry (AMS) analysis of 26 Al. A glass-like material usually resulted which was thought to be aluminum (Al) oxyphosphate. The separation of Al and phosphate was investigated. Al, but not phosphate, was bound by a cation exchange resin (AG 50-X8). Hydrofluoric acid eluted the Al from the resin. Removal of phosphate from acid digested brain by this method produced an amorphous material after ashing that was easier to recover from the porcelain crucible and had a higher AMS beam current. This procedure to separate Al from phosphate may have utility in other applications.
Hole superconductivity and the high-Tc oxides.

We discuss predictions of the hole-pairing mechanism of superconductivity for various experimentally measurable properties of the high-${\mathit{T}}_{\mathit{c}}$ oxides. The model considered describes conduction by holes through the oxygen anion network in the high-${\mathit{T}}_{\mathit{c}}$ oxides, and pairing originates in a term in the Hamiltonian describing an enhanced hopping amplitude for a hole in the presence of other holes. The model includes on-site and nearest-neighbor Coulomb repulsions and different hopping amplitudes within and between planes. We use information from experiments to determine suitable ranges of parameters in the model and examine various properties of the superconducting state within this model using BCS theory. Among the most notable predictions of the model for the high-${\mathit{T}}_{\mathit{c}}$ oxides are: (1) the superconducting state is nearly isotropic despite the anisotropic band structure; (2) the pressure dependence of ${\mathit{T}}_{\mathit{c}}$ is very different for pressure applied perpendicular and parallel to the planes; and (3) the upper critical field and effective mass decrease rapidly and monotonically with hole doping, as a crossover occurs between strong- and weak-coupling regimes.
Competition in private commons: price war or market sharing?

This paper characterizes the outcomes of secondary spectrum markets when multiple providers compete for secondary demand. We study a competition model in which each provider aims to enhance its revenue by opportunistically serving a price-dependent secondary demand, while also serving dedicated primary demand. We consider two methodologies for sharing spectrum between primary and secondary demand: In coordinated access, spectrum providers have the option to decline a secondary access request if that helps enhance their revenue. We explicitly characterize a break-even price such that profitability of secondary access provision is guaranteed if secondary access is priced above the break-even price, regardless of the volume of secondary demand. Consequently, we establish that competition among providers that employ optimal coordinated access leads to a price war, as a result of which the provider with the lowest break-even price captures the entire market. This result holds for arbitrary secondary demand functions. In uncoordinated access, primary and secondary users share spectrum on equal basis, akin to ISM bands. Under this policy, we characterize a market sharing price that determines a provider's willingness to share the market. We show an instance where the market sharing price is strictly greater than the breakeven price, indicating that market equilibrium in an uncoordinated access setting can be fundamentally different as it opens up the possibility of providers sharing the market at higher prices.
The number of extremal components of a rigid measure

The Littlewood-Richardson rule can be expressed in terms of measures, and the fact that the Littlewood-Richardson coefficient is one amounts to a rigidity property of some measure. We show that the number of extremal components of such a rigid measure can be related to easily calculated geometric data. We recover, in particular, a characterization of those extremal measures whose (appropriately defined) duals are extremal as well. This result is instrumental in writing explicit solutions of Schubert intersection problems in the rigid case.
Optical Spectrum of MoS 2 : Many-Body Effects and Diversity of Exciton States

We present first-principles calculations of the optical response of monolayer molybdenum disulfide employing the GW-Bethe-Salpeter equation (GW-BSE) approach including self-energy, excitonic, and electron-phonon effects. We show that monolayer MoS2 possesses a large and diverse number of strongly bound excitonic states with novel k-space characteristics that were not previously seen experimentally or theoretically. The absorption spectrum is shown to be dominated by excitonic states with a binding energy close to 1 eV and by strong electron-phonon broadening in the visible to ultraviolet range. Our results explain recent experimental measurements and resolve inconsistencies between previous GW-BSE calculations.
The role of symmetry in representing reduced density operators and reduced transition density operators: General formulation with specific application to atomic systems

The p-particle reduced transition (density) matrix between a properly chosen given member of one degenerate manifold and a properly chosen given member of a (possibly) different manifold of eigenstates of a nonrelativistic atomic Hamiltonian contains sufficient information to construct the p-particle reduced transition (density) matrix between any member of the first manifold and any member of the second manifold. A synthetic procedure for this construction is presented in this article and is completely spelled out for p = 1. Application of these ideas to the more general symmetries of a molecular system or of an atom in a crystal field is outlined. This procedure is particularly useful when one has made a calculation of the reduced density matrix of the state belonging to one symmetry species within a degenerate manifold and desires the reduced density matrix of another state [or the reduced transition (density) matrix between two states] within the same manifold.
Aplastic anemia terminating in hairy cell leukemia. A report of two cases.

Aplastic anemia and hairy cell leukemia (HCL) characteristically present with a pancytopenia, and several reports have described HCL as mimicking aplastic anemia. Usually the bone marrow core biopsy will easily differentiate these entities, as aplastic anemia is hypocellular, and HCL has a mononuclear cellular infiltrate with increased reticulin. In the experience of the author with 67 cases of HCL, two cases have been encountered that clinically and morphologically appeared to be aplastic anemia before terminating in HCL 23 months and 15 months later, respectively. The clinical courses are described for these two individuals. Hairy cell leukemia may not only mimic aplastic anemia, but on rare occasions, aplastic anemia may actually precede hairy cell leukemia. Cancer 53: 1533- 1537, 1984. AIRY CELL LEUKEMIA (HCL) typically presents with H a cytopenia, and in approximately 50% of the cases with pancytopenia.'-* Pancytopenia is, likewise, the most common peripheral blood manifestation of aplastic anemia. Whereas, aplastic anemia is characterized by bone marrow hypocellularity, HCL is usually associated with effacement of bone marrow architecture by a diffuse mononuclear cellular infiltrate. Occasional reports have described HCL mimicking aplastic anemia.','" Although the marrow was hypoplastic in one case,' an infiltrate of HCL cells could still be found. From a practical view point, it was suggested that HCL be added to the differential list of diseases that must be considered when aplastic anemia is entertained. Two cases of HCL with a preceding clinical and morphologic picture of aplastic anemia have been encountered by the author in the last 8 years. These cases are described in detail.
Dicey’s Ghost and Administrative Law:

Albert Venn Dicey, the great British constitutional scholar of the 19th century, is best known in the field of administrative law for his denial of even the possibility of administrative law in common-law countries. This article puts Dicey’s famous denial in a context that establishes the relevance of his constitutional scholarship for contemporary administrative law. Examples are drawn from the United Kingdom and the United States to support this position.
NEW URBANISM AND THE CULTURE OF CRITICISM

Opinions about new urbanism have polarized. From the academy, analysts have generally nurtured a vigorous contempt for new urbanism, while planning practitioners view it simply as the most recent articulation of a reoccurring planning theme: simple clusters of housing, retail space, and offices within a quarter-mile walking radius of a transit system. In this paper, I argue that while there is much to discredit in current applications of new urbanism, there is a need to recast the debate in such a way that the principles of new urbanism can be upheld and specific applications can be continually revised. A recast debate would focus on either: (1) the underlying conceptual framework required for proper discussion of any normative planning; (2) the specific normative principles of new urbanism; (3) the descriptive assumptions used by new urbanists; or (4) the specific experiences of, to date, applied new urbanism. To articulate the specifics of this recast debate, I argue the following: (1) that there are tw...
Bone Mineral Density in Adults Disabled Through Acquired Neurological Conditions: A Review

Abstract This article is a review of the changes in bone mineral density (BMD), which occur in a number of acquired neurological conditions resulting in disability. For each of spinal cord injury, stroke, multiple sclerosis, Parkinson's disease, and traumatic brain injury, the following aspects are discussed, where information is available: prevalence of low BMD according to World Health Organization diagnostic categories and recommended diagnostic method, prevalence based on other diagnostic tools, comparison of BMD with a control population, rate of decline of BMD following onset of the neurological condition, factors influencing decline; mechanism of bone loss, and fracture rates. The common risk factors of immobilization and vitamin D deficiency would appear to cross all disability groups, with the most rapid phase of bone loss occurring in the acute and subacute phases of each condition.
A Note on Parametric Network Flows

In their paper [Doulliez, P. J., M. R. Rao. 1971. Maximal flow in a multi-terminal network with any one are subject to failure. Management Sci.18 1, September 48--58.], Doulliez and Rao present algorithms that solve two flow problems for a single source, multi-terminal network. The first problem that they solve is the construction of a flow that maximizes the value of t, where the demand at each sink is a nondecreasing, linear function of t. Given such a flow, the second problem that they solve is the construction of a flow that maximizes the value of t when the capacity of an arc is reduced. This paper supplies a finiteness proof for the first algorithm and sketches a finiteness proof for the second algorithm. The proofs are based on the well-known fact that a network possesses only a finite number of different spanning trees.
The decomposition of chemically activated n–butane, isopentane, neohexane, and n–pentane and the correlation of their decomposition rates with radical recombination rates.†‡

The total decomposition rates of the chemically activated alkanes n-butane, n-pentane, isopentane, and neohexane were measured using an internal comparison technique. Chemical activation was by the CH insertion reaction of excited singlet-state methylene radicals. A total of ten rate constants ranging from 4.6 × 105 to 2.3 × 107 sec−1 were measured for these alkanes at different excitation energies. These rates correlate via RRKM theory calculations with thermal A-factors in the range of 1016.1 to 1017.1 sec−1 for free rotoractivated complex models and in the range of 1016.4 to 1017.8 sec−1 for vibrator-activated complex models. It was found that high critical energies for decomposition, “tight” radical models, and activated complex models with free internal rotations were required to correlate the decomposition rates of these alkanes with estimated alkyl radical recombination rates. The correlation is just barely possible even for these favorable extremes, indicating that there may be a basic discrepancy between the recombination rate and decomposition rate data for alkanes.
University undergraduate students and library-related privacy issues

New technologies increase the ability to capture and retrieve data about library usage patterns and users. Collecting, analyzing, and using patron data, however, may raise concerns among library users about their online privacy and how the data collected might be used to their advantage or disadvantage. This article examines undergraduate students' knowledge and perceptions of online privacy issues, their opinions regarding who should collect and retain information about them, for what purposes, and under what circumstances.
Growth, Trade, and Deindustrialization

This paper shows that deindustrialization is explained primarily by trends internal to the advanced economies. These include the combined effects on manufacturing employment of a relatively faster growth of productivity in manufacturing, the associated relative price changes, and shifts in the structure of demand between manufactures and services. North-South trade explains less than one fifth of deindustrialization in the advanced economies. Moreover, the contribution of North-South trade to deindustrialization has been mainly through its effects in stimulating labor productivity in Northern manufacturing. It has had little enduring effect on total manufacturing output in the advanced economies.