cssi/SciSciGPT-SciSciNet huggingface dataset:
Novel tetranuclear copper(II) complex of dicarboxyamine ligand: Syntheses, crystal structures and redox properties

Abstract The reaction between a new amino dicarboxylic ligand N-(2-carboxybenzomethyl)-β-alanine (H2cbal) obtained by reducing the Schiff base N-(2-carboxybenzoimine)-β-alanine and copper(II) perchlorate afforded a novel tetracopper(II) complex. This tetracopper(II) complex shows unusual structure and novel core topology. The electrochemical study of the complex using cyclic voltammetrry in acetonitrile indicated the presence of a reversible one-electron reduction and two irreversible reductions at higher potentials. The EPR studies of the complex and one electron reduce form of the complex in acetonitrile at 115 K showed an axial signal with g∥ > g⊥ > 2.0 and an isotropic signal, respectively.
Evaluating velocity measurement techniques in shallow streams

Accurate flow field measurements in shallow rivers are necessary for many applications including biological investigations and numerical model development. Unfortunately, river velocity data is difficult to obtain due to the limitations of traditional velocity meters. Acoustic Doppler Current Profilers (ADCP) provide a potential alternative to traditional point-velocity measurements. However, these instruments have not been thoroughly tested against accepted techniques in natural streams. The objectives of this research were to evaluate the adequacy of ADCP instruments for conducting velocity measurements in quasi-wadeable streams and to provide instrument selection guidance for similar flow environments. These objectives were met by conducting ADCP, Acoustic Doppler Velocimeter (ADV), and Price current meter measurements at nine coinciding verticals in two rivers. The performance of each instrument was evaluated with regards to data accuracy, desired parameters, and required sampling time. ADCP measureme...
Does e − aq +H 3 O + aq give H Atoms Directly?

FOUR discussions1–4 may leave the reader in some doubt as to the direct reaction product P of the aqueous reaction Open image in new window which is commonly believed to give H atoms (P=H).
Condensed-matter physics: The conducting face of an insulator

Stacking two oxide insulators together is known to yield a conducting system at the interface between the oxides. But the discovery that simply cleaving such an insulator yields the same outcome is unexpected. See Letter p.189 At surfaces or interfaces of materials, electronic states can form that have novel properties that are different from the bulk. Tailoring such properties in thin film oxide devices has led to a new field of research — known as oxide electronics — in which the material strontium titanate (SrTiO3) takes a central role. In particular, an exotic two-dimensional electron gas (2DEG) forms at oxide interfaces based on SrTiO3, but the precise nature of the 2DEG has remained elusive. Santander-Syro et al. carry out a systematic study using angle-resolved photoemission spectroscopy (ARPES), and obtain new insights into the electronic bandstructure of the 2DEG. Their findings shed light on previous observations in SrTiO3-based heterostructures and suggest that different forms of electron confinement at the surface of SrTiO3 lead to essentially the same 2DEG.
Light leptoquarks as possible signature of strong-electroweak unification.

In strong-electroweak unification, based on SU(15), with baryon number (B) and lepton number (L) conserved, bosons with B=±2/3, L=0 (diquarks), B=0, L=±2 (dileptons) and B=±1/3, L=±1 (leptoquarks) can occur at “light” (≤ TeV) scales. The discovery of light leptoquarks would be evidence as compelling as proton decay for grand unification.
Production of Radioisotopes in the ORNL 86-Inch Cyclotron

The radioisotope production facilities and programs of the 86-Inch Cyclotron are reviewed in this presentation. The 86-Inch Cyclotron is designed to accelerate protons to a maximum energy of 22 MeV for internal targets. These protons are used to bombard metals that are electroplated, potted or soldered to water-cooled plates. Additionally, metals and inorganic compounds are bombarded in water-cooled tube targets. High radioisotope production rates are obtained by beam currents as large as 3 mA. Production rates for llC, 57Co, 67Ga, 68Ge, 109Cd, and other isotopes are presented. The production of 11C for the carboxyl labeling of amino acids in cooperation with Oak Ridge Associated Universities is discussed. The 86-Inch Cyclotron is used for those programs requiring a larger beam current than is available from commercial cyclotrons.
Regulation of the external mycoflora of the giant Madagascar hissing-cockroach, gromphadorhina portentosa , by its mite associate, gromphadorholaelaps schaeferi , and its implications on human health

The giant Madagascar hissing-cockroach,Gromphadorhina portentosa, and its mite associate,Gromphadorholaelaps schaeferi, constitute an intimate commensalistic symbiosis. While the mite’s very survival is dependent by feeding on cockroach saliva and associated organic debris, the degree that the cockroach benefits from this association is unclear. We investigated the mite’s potential role at regulating surface fungi on the exoskeletons of this insect. Numbers of fungal isolates that resulted were compared between captive-bred cockroaches with and without mites. The mycoflora of both groups consisted of common molds (Alternaria sp.,Aspergillus sp.,Cladosporium sp.,Geotrichum sp.,Mucor sp.,Penicillium sp.,Rhizopus sp.,Trichoderma sp.). The presence of mites reduced the number of isolates by 1/2 in mature females, 1/3 in males, and 1/4 in sixth (final) instar nymphs. Fungus levels continued to drop when mite-free cockroaches were artificially supplemented with mites. A direct correlation was detected between mites and the reduction in the quantity of surface molds up to 20 mites per cockroach. The addition of more mites above 20 per cockroach, even 4x more, had a minimal, but still reducing, effect. Mites regulated all types of fungi, not just a select few taxa. We propose that mites reduce the mycoflora not because they consume fungi, but because mites and molds compete for the same resources in an ecological niche, saliva and organic debris that accumulate in between cockroach’s legs. Cockroaches reared in captivity do not apparently benefit by the removal of surface molds by mites, lending support for a commensalistic symbiosis. This cockroach species has been linked to severe allergic reactions in children, in part, because it harbors antagonistic molds. GivenG. schaeferi’s regulatory role at suppressing fungi, these mites could conceivably impose a small indirect, albeit beneficial role to humans by reducing the amount of fungal inoculum (conidia) that might otherwise be inhaled.
Cognitive Demands of Semi-Natural Virtual Locomotion

Abstract There is currently no fully natural, general-purpose locomotion interface. Instead, interfaces such as gamepads or treadmills are required to explore large virtual environments (VEs). Furthermore, sensory feedback that would normally be used in real-world movement is often restricted in VR due to constraints such as reduced field of view (FOV). Accommodating these limitations with locomotion interfaces afforded by most virtual reality (VR) systems may induce cognitive demands on the user that are unrelated to the primary task to be performed in the VE. Users of VR systems often have many competing task demands, and additional cognitive demands during locomotion must compete for finite resources. Two studies were previously reported investigating the working memory demands imposed by semi-natural locomotion interfaces (Study 1) and reduced sensory feedback (Study 2). This paper expands on the previously reported results and adds discussion linking the two studies. The results indicated that locomo...
A Bias Toward Short-Term Thinking in Threat-Related Negative Emotional States

Some decisions must be made repeatedly and have consequences that change depending on how often each alternative is chosen. Such temporally extended decisions are pervasive and important, and often involve short-term/long-term tradeoffs. Can unrelated emotion and stress influence such decisions? In negative emotional states involving threats, people should favor what is better at the time regardless of possible long-term consequences. Supporting this hypothesis, in Experiment 1, college students randomly assigned to see aversive images repeatedly made choices that had better short-term but poorer long-term effects, and so earned less money than students shown neutral images, effect size r = .71. In Experiment 2, students reporting stress about impending exams showed a similar bias, r=.53.Thehypothesis and results are relevant to decision making, delay of gratification, distributed choice, and self-control.
Patient risk-taking attitude and the use of complementary and alternative medical services.

Objectives: Study users and nonusers of complementary and alternative medicine (CAM) with respect to their attitude toward risk. Settings and subjects: National household telephone survey fielded i...
Recrystallization and solubility of 1,3,5-triamino-2,4,6-trinitrobenzene in dimethyl sulfoxide

The insensitive explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) has been recrystallized from dimethylsulfoxide (DMSO) with particle sizes ranging up to 2 mm diameter. Crystal growth was controlled by varying the heating and cooling rates and the solution agitation speed. The role of additives and “green” u.v. radiation-induced impurity in affecting crystal morphology, size, and colour was also studied. To provide the thermal concentration data needed for the crystallization study, the solubility curve of TATB in DMSO was determined gravimetrically. The solubility data spans the range of 0.47±0.23 gl−1 at 21.2 °C to 6.80±1.13 gl−1 at 145.5 °C.
Diversity during training enhances detection of novel stimuli

This research demonstrates that when individuals are expected to detect novel targets, they will be best prepared when trained with diverse categories. Participants were trained in a simulated luggage screening task in one of three conditions of diversity: high (participants searched for dangerous objects belonging to five different categories); low (participants searched for targets belonging to one of the five categories); and no training (control condition). After training, all participants were asked to look for the same novel dangerous objects in the bags. Results show that, during training, the low diversity condition resulted in highest hit rates and fastest response times. In contrast, after training, results were reversed: participants that trained in a high diversity condition were most effective at detecting novel targets. Those with no training at all were equally poor at detecting novel targets as those that trained in a low diversity condition.
Thermal decay of the V-band in MgO quenched from high temperature

Experimental studies of the effects of quenching and annealing in the range 650 to 1250 K on the so called V-band absorption in MgO single crystals have been carried out. Optical absorption in the visible and infrared spectral range of irradiated and unirradiated crystals, together with density changes attendant upon heat treatment, were used to gain insight into the nature of the centers and the kinetic processes involved. It is shown that the enhancement by prior quenching of the radiation induced 2.3 eV V-band absorption is reversible with quench temperature; at any annealing temperature it approaches a limiting value which differs from specimen to specimen. This behavior is similar to that observed earlier for the 3296 cm−1 V−OH band which suggests a connection between the V-band enhancement and the concentration of V−OH complexes present, namely, that the enhancement is due to an increase in VOH concentration in the quenched and irradiated crystals. Isothermal annealing of the V-band enhancement in the range 650 to 850 K reveals that the decay process is bimolecular with an activation energy of 1.5 eV. The similarity of this behavior to the decay of V−OH along with the results of bulk density measurements during annealing lend strong support to the model suggested by Henderson and Sibley that the V-band enhancement results from the increased solubility of Mg(OH)2 in the form of cation vacancy OH− complexes with increasing temperature. Experimentelle Untersuchungen uber die Auswirkungen von Abschrecken und Tempern im Bereich von 650 bis 1250 K auf die sogenannte V-Banden-Absorption in MgO-Einkristallen wurden durchgefuhrt. Die optische Absorption im sichtbaren und infraroten Bereich von bestrahlten und unbestrahlten Einkristallen, zusammen mit Dichteanderungen durch Warmebehandlung, werden benutzt, um Einsicht in die Art der Zentren und die kinetischen Vorgange zu erhalten. Es wird gezeigt, das die durch vorheriges Abschrecken hervorgerufene Verstarkung der strahlungsinduzierten 2,3 eV V-Banden-Absorption reversibel mit der Abschrecktemperatur ist; bei jeder Temperungstcmperatur erreicht sie einen Grenzwert, der von Probe zu Probe anders ist. Dies ahnelt dem schon fruher fur die 3296 cm−1 V−OH- Bande beobachteten Verhalten und weist auf eine Verbindung zwischen der V-Banden-Verstarkung und der Konzentration von V−OH Komplexen hin, namlich, das die Verstarkung von einer Zunahme der VOH-Konzentration in den abgeschreckten und den bestrahlten Kristallen stammt. Isothermes Tempern der V-Banden-Verstarkung im Bereich von 650 bis 850 K zeigt, das der Zerfallsprozes bimolekular ist, mit einer Aktivierungsenergie von 1,5 eV. Die Ahnlichkeit zwischen diesem Verhalten und dem Zerfall von V-OH, zusammen mit den Ergebnissen von Dichtemessungen wahrend des Temperns, unterstutzen das von Henderson und Sibley vorgeschlagene Modell, das die V-Banden-Verstarkung von der erhohten Loslichkeit von Mg(OH)2 in der Form von Kationleerstellen-OH−-Komplexen bei erhohten Temperaturen herruhrt.
Rat Olfactory Bulb Mitral Cells Receive Sparse Glomerular Inputs

Center-surround receptive fields are a fundamental unit of brain organization. It has been proposed that olfactory bulb mitral cells exhibit this functional circuitry, with excitation from one glomerulus and inhibition from a broad field of glomeruli within reach of the lateral dendrites. We investigated this hypothesis using a combination of in vivo intrinsic imaging, single-unit recording, and a large panel of odors. Assuming a broad inhibitory field, a mitral cell would be influenced by >100 contiguous glomeruli and should respond to many odors. Instead, the observed response rate was an order of magnitude lower. A quantitative model indicates that mitral cell responses can be explained by just a handful of glomeruli. These glomeruli are spatially dispersed on the bulb and represent a broad range of odor sensitivities. We conclude that mitral cells do not have center-surround receptive fields. Instead, each mitral cell performs a specific computation combining a small and diverse set of glomerular inputs.
The Pelham gneiss dome, Massachusetts

The Pelham gneiss dome in central-northern Massachusetts, east of the Connecticut Valley, measures about 27 by 7 miles. Its axis strikes north-south, and the northern end is three miles south of the New Hampshire Border. Gneissic foliation is remarkably well developed throughout the dome. The planes lie subhorizontal along the axis, and on the symmetric western and eastern slopes the dip rarely exceeds 45°.
Division Algebras Not Embeddable in Crossed Products

Abstract We show that division algebras do not always embed in crossed product division algebras, so the latter do not serve as “Galois closures” for division algebras. We construct decomposable noncrossed product division algebras of prime-power index over rational function fields and Laurent series fields over number fields. We discover a rigid nonabelian group of order p 4 .
Probing friction and adhesion properties of poly(vinyl methylether) homopolymer and blend films under nano-confinement using atomic-force microscopy

Abstract The surface properties of poly(vinyl methylether) (PVME) homopolymer and blend films are characterized by atomic force microscopy (AFM) with the film thickness ranging from 5 nm to 400 nm. When the film thickness is less than 200 nm, lateral force of the PVME films decreases with the decreasing film thickness and has less dependence on the scanning rate. The local adhesion measurements indicate the adhesion force per unit area increases with the decreasing film thickness. These results are consistent to each other showing the increased polymer stiffness and decreased polymer chain mobility due to the confinement in the ultra-thin films. The effects of blending PVME with semicrystalline isotactic polypropylene (i-PP) on the lateral force of the film have also been investigated. Upon blending, both the scale of the lateral forces and their scanning rate dependences exhibit great changes. The lateral force of the blend film has a maximum when the fraction of PVME is around 0.8, similar to that when a polymer goes through the glass-transition. To cite this article: D. Wang, H. Ishida, C. R. Chimie 9 (2006).
Polarimetric pulse propagation through discrete random media

In this paper, we examine numerical solutions of the two- frequency radiative transfer equation to study pulse propagation through discrete random media. Specifically, we examine the plane-parallel problem using the Henyey- Greenstein phase function for scalar problems and Mie scattering for polarimetric problems. Since standard methods such as the discrete ordinate method and the finite element method are not numerically stable for polarimetric problems at large optical depths, we introduce a Chebyshev spectral method to solve these problems. Then, we examine a few examples of optical pulses in fog layers and millimeter wave pluses in rain layers, and compare our results to first- order scattering and diffusion approximations.
A method for the study of interstimulus similarity

A generalized method for collecting data on interstimulus similarity is presented and its special cases evaluated by use of information theory. A method of analyzing the data by the Unfolding Technique is presented which permits the study of the latent attribute structure underlying the similarity of stimuli for a single individual.
Coupling of underground objects to antennas and transmission lines at antiresonance

The changes in input impedance for a simple antenna or transmission line located over a soil containing a conducting object are examined near antiresonance. The near-field coupling of the underground object to the antenna or transmission line is investigated using the complex Poynting vector in order to identify the contribution of traveling and/or standing waves.
The Endothelium as a Target in Pediatric OSA

Pediatric sleep disordered breathing has emerged in the last few decades as a highly prevalent condition by virtue of its major morbidities encompassing the central nervous, cardiovascular, and metabolic systems. In this context, improved understanding of the pathophysiological mechanisms underlying the cellular and organ injury and repair mechanisms, and the variance of the phenotype at any level of disease severity is all the more critical if appropriate personalized therapies are to be developed in the future. In this paper, the current evidence and hypothetical framework pointing to the endothelium as a primary cellular target for many of the morbidities of pediatric sleep apnea is reviewed, and particular emphasis on the recruitment of the endothelial cell lineage will be explored. It is hoped that this perspective will foster both expansion and acceleration of discovery efforts aiming to ultimately prevent the potentially lifelong consequences of sleep apnea during childhood.
Towards Optimal Cooperative Caching in Social Wireless Networks

This paper introduces an optimal cooperative caching policy for minimizing electronic content provisioning cost in Social Wireless Networks (SWNETs). The SWNETs are typically formed by a collection of mobile devices, such as data enabled phones, net-books, electronic book readers etc., sharing common interests in electronic content, and physically gathering in settings such as University campuses, work places, malls, airports, train stations and other public places. Electronic object caching in such SWNETs are shown to be able to reduce the content provisioning cost which depends heavily on the service and pricing dependencies among various stakeholders including the content provider, the network service provider, and the end consumers. Drawing motivation from Amazon''s Kindle electronic book delivery business, this paper develops a practical network, service, and pricing model which are then used for creating the proposed optimal caching strategy. In addition to proving the optimality of the mechanism, the paper constructs extensive analytical and simulation models for analyzing the proposed caching strategy and its optimal operating points for the mobile ecosystem stakeholders.
The Aleutian Low, storm tracks, and winter climate variability in the Bering Sea

Previous studies have found inconsistent results regarding how wintertime conditions in the Bering Sea relate to variations in the North Pacific climate system. This problem is addressed through analysis of data from the NCEP/NCAR Reanalysis for the period 1950–2003. Composite patterns of sea-level pressure, 500 hPa geopotential heights, storm tracks and surface air temperature are presented for four situations: periods of strong Aleutian Low, weak Aleutian Low, warm Bering Sea air temperatures, and cold Bering Sea air temperatures. Winter temperatures in the Bering Sea are only marginally related to the strength of the Aleutian Low, and are much more sensitive to the position of the Aleutian Low and to variations in storm tracks. In particular, relatively warm temperatures are associated with either an enhanced storm track off the coast of Siberia, and hence anomalous southerly low-level flow, or an enhanced storm track entering the eastern Bering Sea from the southeast. These latter storms do not systematically affect the mean meridional winds, but rather serve to transport mild air of maritime origin over the Bering Sea. The leading indices for the North Pacific, such as the NP and PNA, are more representative of the patterns of tropospheric circulation and storm track anomalies associated with the strength of the Aleutian Low than patterns associated with warm and cold wintertime conditions in the Bering Sea.
Redo infrainguinal bypass: Factors predicting patency and limb salvage

The increased complexity of redo infrainguinal bypass procedures can result in prolonged operative time and increased morbidity. This review was undertaken to compare outcomes from primary and redo bypass procedures and to identify factors predictive of graft failure and limb loss after redo bypass. All infrainguinal bypasses (n = 468) from 1995 to 1999 were reviewed. A total of 367 primary bypasses in 317 patients were compared to 101 redo grafts in 84 patients with previously failed bypasses. Risk factors and types of procedures were compared using Student’s t-test and the χ2 test. Patency and limb salvage were compared using life-table analysis. Patients requiring redo bypasses were less likely to have diabetes and end-stage renal disease. Two-year patency (66 ± 4% primary vs. 55 ± 7% redo, p = 0.13) and limb salvage (75 ± 3% primary vs. 72 ± 6% secondary, p = 0.43) were comparable between primary and redo bypass groups. Female gender was predictive of redo graft failure (2-year patency 73 ± 8% male vs. 39 ± 9% female, p = 0.01). Clinical indications that predicted failure of a redo bypass included thrombosis of an autologous graft (1-year patency 71 ± 7% previous prosthetic vs. 49 ± 10% previous autologous, p = 0.004), thrombosis of an infrageniculate bypass (2-year patency 65 ± 10% suprageniculate vs. 46 ± 9% infrageniculate, p = 0.044), and a limb salvage indication for the primary operation (2-year patency 86 ± 9% claudication vs. 44 ± 8% limb salvage, p = 0.008). When a primary bypass fails despite the use of optimal conduit (autologous vein) and an infrageniculate target vessel, the redo bypass has a higher risk of failure, particularly in female patients. Nonetheless, patency and limb salvage rates justify an attempt at revascularization after failed primary bypass.
Fillers in insulation for rotating electrical machines

Salient considerations of insulation behavior when fillers are utilized are reviewed. The authors seek to clarify the current supporting science for engineering filled polymeric systems specifically for rotating electric machines. Included is a brief discussion of possible property improvements with the use of fillers. An expanded micro-mechanical approach to describing insulation behavior would be useful for pursuing further improvements in reduced insulation aging and insulation lifetime prediction.
Characterizing Consent: Race, Citizenship, and the New Restrictionists:

Birthright citizenship provides a key to more racially equalitarian policy. This article explores the use of consensual citizenship to challenge the tradition of birthright citizenship in the Unite...
Circulating C-Type Natriuretic Peptide and Its Relationship to Cardiovascular Disease in the General Population

C-type natriuretic peptide (CNP) is an endothelium-derived peptide that is released as a protective mechanism in response cardiovascular injury or disease. However, no studies have investigated circulating CNP, identifying clinical factors that may influence CNP and its relationship to cardiovascular disease in the general population. We studied 1841 randomly selected subjects from Olmsted County, MN (mean age, 63±11 years; 48% men). Plasma CNP was measured by a well-established radioimmunoassay and echocardiography, clinical characterization, and detailed medical record review were performed. We report that CNP circulates at various concentrations (median, 13 pg/mL), was unaffected by sex, was weakly associated by age, and that highest quartile of CNP identified a high-risk phenotype. Subjects with CNP in the highest quartile were associated with increased risk of myocardial infarction (multivariable-adjusted hazard ratio, 1.51; 95% confidence interval, 1.09-2.09; P=0.01) but not heart failure, cerebrovascular accidents, or death during a follow-up of 12 years. Addition of the highest quartile of CNP to clinical variables led to a modest increase in the integrated discrimination improvement for risk of myocardial infarction. In a large community-based cohort, elevated circulating CNP identified a high-risk phenotype that included cardiovascular comorbidities and left ventricular dysfunction, and provided evidence that highest concentrations of CNP potentially has prognostic value in predicting future risk of myocardial infarction. Together, these data from the general population highlight the potential value of CNP and support the need for additional studies to evaluate whether mechanisms regulating CNP could improve outcomes.
One dose of cyclosporine A is protective at initiation of folic acid-induced acute kidney injury in mice

Background. In most patients, acute kidney injury (AKI) represents the combined effects of ischemic, toxic and inflammatory insults. No effective pharmacologic interventions have been developed to prevent AKI or to improve outcomes to date. Cyclosporine A (CsA) is a calcineurin inhibitor that mediates T-cell receptor signaling, suppresses inflammatory cytokine expression and inhibits leukocyte migration. It is also a potent inhibitor of mitochondrial permeability, protecting cells from death. These properties make it a potentially valuable drug to prevent or treat AKI. It does, however, carry a significant risk of nephrotoxicity, especially with chronic use. By contrast, a single dose of CsA may be protective while limiting the risk of nephrotoxicity. Methods. We conducted a controlled animal experiment in male CD-1 mice. Specifically, mice were subjected to folic acid (FA)-induced AKI and then randomly assigned to sham operation or one of three dosage of CsA treatment groups. Results. Intraperitoneal injection of FA consistently induced AKI. Serum interleukin (IL)-6 and urinary neutrophil gelatinase-associated lipocalin (NGAL) rose 1 day after FA injection. Compared to sham treatment, one dose (1 and 5 mg/kg body weight) of CsA significantly reduced kidney tubular cell apoptosis, serum creatinine, blood urea, serum IL-6 and urinary NGAL 2 days after FA injection. It was also shown to block the inflammatory mediator tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) expression, nuclear factor kappa-B (NFκB) activation, inflammatory cell infiltration and interstitial fibrosis 14 days after treatment in a dose-dependent fashion. By contrast, a dose of 10 mg/kg body weight CsA resulted in nephrotoxicity in the setting of FA-induced AKI. Conclusions. A single dose of CsA, currently used for organ transplant, significantly protects mice from FA-induced AKI, presumably through inhibition of cell death, inflammatory reaction, interstitial cell infiltration and fibrosis. The protective effects have the potential to open a completely new line of investigation in the prevention and treatment of AKI.
African and European Bound Labor in the British New World: The Biological Consequences of Economic Choices

This article offers an explanation for the regional differences in the use of African and European bound labor in colonial America. The migrations of Africans and Europeans to the Americas set in motion an evolutionary process that caused regional changes in the disease ecology of the New World. Biological and epidemiological differences among populations explain the different regional labor supply choices. This article emphasizes the interactions between changing populations and disease environments. Diseases are intermediaries through which populations interact by causing illness and death. Not all populations are equally afflicted by specific diseases. Therein lies the story.
Holophrases, Speech Acts and Language Universals.

The arguments both for and against viewing the child's initial one-word utterances as HOLOPHRASES are reviewed. Some theoretical problems – concerning the innateness of language, the acquisition of syntax, the status of prosody and the child's comprehension of language during the one-word stage – with the holophrase controversy are pointed out. We suggest that an unresolvable theoretical stalemate exists because proponents on both sides of the controversy mistakenly assume the centrality of the notion sentence in discussing holophrases. An alternative view of early language development, which takes the SPEECH ACT as the basic unit of linguistic communication, is offered as a solution to the problems with the holophrase controversy as it now stands. We propose a more integrated description of the relations between functional and grammatical aspects of early communicative competence than is currently provided by sentence-oriented theories. In particular, we suggest that the child's PRAGMATIC INTENTIONS gradually become GRAMMATICALIZED as semantic and syntactic structures. Finally, three entities – communicative functions, referring expressions and predicating expressions – are proposed as LANGUAGE UNIVERSALS, as distinct from grammatical universals.
The hydrogen bond strength of the phenol–phenolate anionic complex: a computational and photoelectron spectroscopic study

The phenol–phenolate anionic complex was studied in vacuo by negative ion photoelectron spectroscopy using 193 nm photons and by density functional theory (DFT) computations at the ωB97XD/6-311+G(2d,p) level. We characterize the phenol–phenolate anionic complex as a proton-coupled phenolate pair, i.e., as a low-barrier hydrogen bond system. Since the phenol–phenolate anionic complex was studied in the gas phase, its measured hydrogen bond strength is its maximal ionic hydrogen bond strength. The D(PhO−⋯HOPh) interaction energy (26–30 kcal mol−1), i.e., the hydrogen bond strength in the PhO−⋯HOPh complex, is quite substantial. Block-localized wavefunction (BLW) computations reveal that hydrogen bonded phenol rings exhibit increased ring π-electron delocalization energies compared to the free phenol monomer. This additional stabilization may explain the stronger than expected proton donating ability of phenol.
Characterization and adsorptive properties of pharmaceutical grade clays

The adsorption of tetracycline by clays commonly used in pharmacy can be predicted if the identity and character of the commercial clay sample are established. X-ray diffraction, IR spectroscopy, and chemical analysis were used to identify the clay component and any nonclay diluents present in a series of commercial pharmaceutical grade clays. The major clay components were montmorillonite, hectorite, attapulgite, saponite, and kaolinite. The clay structure, the nature of the exchangeable cation, and the presence of nonclay components are important factors affecting the tetracycline–clay interaction. In general, clay structures with a high surface charge lead to a greater interaction with the protonated form of tetracycline, while interaction with the zwitterionic form of tetracycline occurs in clay structures with minimal surface charge. The presence of multivalent, exchangeable cations on the clay surface diminishes interaction with the protonated form of tetracycline. Nonclay components such as calcite and dolomite increase the interactions of the zwitterionic and anionic forms of tetracycline with the clay.
Ontogeny of macrophage resistance to mouse hepatitis in vivo and in vitro.

Adult or weanling C3H mice were found to be genetically resistant to a strain of mouse hepatitis virus. Infant C3H mice, however, developed infection and died from mouse hepatitis virus when minimal infectious doses of virus were given to them. There was a delay in the time of death compared to that of the genetically susceptible strain, and the virus recovered from these mice had increased pathogenicity for C3H mice. The ontogeny of resistance to hepatitis in the C3H mice thus progresses from delayed susceptibility to complete resistance as the age of the host increases. It is reflected in increased resistance of macrophages derived in vitro from liver cultures of infant mice of different ages. This increase in resistance with age was reduced by maintaining the cultures for a longer period of time before inoculation, or by increasing the number of explants in a given culture. Resistant cells were uniformly furnished by mice age 16 days, or more. It is concluded that a process of maturation of resistance of the cells takes place after the mice are born, but that this does not continue under in vitro conditions, and that it may be modified by the environment of the cells.
The Three-Phase Terrain of Heart Failure Readmissions

Hospitalization for management of heart failure is a sentinel event with important prognostic implications.1 Despite considerable advances in medical therapy, rates of mortality and readmission after heart failure hospitalization remain high.2 More than half of patients with heart failure are readmitted within 6 months of discharge,3,4 and one in 5 are dead by 1 year.5 The Medicare tab for the roughly one million heart failure hospitalizations annually in the United States alone exceeds $17 billion.6 Readmission rates vary widely among hospitals4 and some have projected that up to three fourths of readmissions may be preventable.7 Policymakers have increasingly targeted reduction in measured readmission rates as a means to simultaneously improve quality of care and reduce costs. Article see p 414 Recent legislation and evolving pay-for-performance initiatives have placed particular emphasis on reducing readmissions in the 30-day interval after discharge on the assumption that outcomes in this window can be influenced by greater attention to improving in-hospital heart failure treatment and care transitions. Although easily tracked and intuitively appealing, however, the 30-day metric may be shortsighted. Discharge from a heart failure hospitalization is followed by early readmission in approximately 24% of cases,3 but a minority of rehospitalizations in this window may be truly preventable.7 As well, these early readmissions may be driven more by patient- and community-level factors than care processes under hospital or provider control.4 The apparent inverse relationship between 30-day hospital readmission and mortality rates8 underscores that early readmissions may occasionally reflect enhanced access to hospital care for those with urgent needs rather than poor-quality care.9 Excessive …
Mediascapes: Context-Aware Multimedia Experiences

Here we describe research addressing the next generation of mobility technology, which will deliver "the right experience in the right moment." The maturing field of pervasive computing yields the technology and the challenges described here. We focus on rich interactive mobile experiences triggered by context information available from the users, their environment, and a wealth of context-enabled content. We call such applications mediascapes.
Using Section 111 of the Clean Air Act for Cap-and-Trade of Greenhouse Gas Emissions: Obstacles and Solutions

EPA is moving forward with section 111 regulation of greenhouse gases. The next step could be creating a cap and trade system for the electrical utility industry, using “standard of performance” as the statutory foundation. Past litigation on EPA’s proposed mercury cap-and-trade program provides insights about potential challenges to a carbon trading program. This paper describes those insights and discusses how EPA could define a standard of performance for greenhouse gas emissions in terms of a national cap and then allow regulated facilities to use allowances to cover their greenhouse gas emissions. This paper also looks to the specifics of the proposed California cap-and-trade program, in order to demonstrate how EPA could allow states to use their participation in regional cap-and-trade programs to comply with section 111(d) requirements for existing sources.
Increases in excitability of neurons of the motor cortex of cats after rapid acquisition of eye blink conditioning.

Measurements were made of resting potentials, input resistance, and excitability to intracellularly applied, depolarizing current pulses in neurons of the pericruciate cortex of conscious cats before and after acquisition of a rapidly conditioned eye blink reflex (CR). Neuronal excitability increased after conditioning, and an increased input resistance was found to be correlated with the increased level of excitability. No associated changes were found in resting potentials as a consequence of conditioning. When cells were divided into groups according to the latency of spike activity elicited by a click conditioned stimulus (CS) in relation to four separate excitatory EMG components of the compound blink CR, excitability increases were found in cells with increased spike activity at alpha 1 (8–40 msec), alpha 2 (40–72 msec), beta (72–112 msec), and gamma (112–160 msec) latencies after delivery of the CS. Also, the proportion of cells with high excitability (less than 0.7 nA required for spike elicitation) was increased at each latency period after conditioning. Increases in later components of spike discharge could also be found in the cells with increases in earlier components of discharge and increased excitability. The findings suggested that excitability increases facilitated a responsiveness to the CS that supported production of long- as well as short-latency components of the blink CR. Many of the changes in neuronal properties found after rapid eye blink conditioning, such as the increases in excitability and resistance and in the proportion of CS-excitable cells, resembled changes found earlier after acquisition of a slowly developing Pavlovian blink CR, using the same click CS and tap unconditioned stimulus without addition of a hypothalamic stimulus. The possibility should be considered that the (10–100 times) more rapidly acquired form of eye blink conditioning does not represent a different form of conditioning, but instead a change in the rate of conditioning supported by the more rapid production of increases in neural excitability.
Asymmetric hybridization and gene flow between Joshua trees (Agavaceae: Yucca) reflect differences in pollinator host specificity

The angiosperms are by far the largest group of terrestrial plants. Their spectacular diversity is often attributed to specialized pollination. Obligate pollination mutualisms where both a plant and its pollinator are dependent upon one another for reproduction are thought to be prone to rapid diversification through co-evolution and pollinator isolation. However, few studies have evaluated the degree to which pollinators actually mediate reproductive isolation in these systems. Here, we examine evidence for hybridization and gene flow between two subspecies of Joshua tree (Yucca brevifolia brevifolia and Yucca brevifolia jaegeriana) pollinated by two sister species of yucca moth. Previous work indicated that the pollinators differ in host specificity, and DNA sequence data suggested asymmetric introgression between the tree subspecies. Through intensive sampling in a zone of sympatry, a large number of morphologically intermediate trees were identified. These included trees with floral characters typical of Y. b. jaegeriana, but vegetative features typical of Y. b. brevifolia. The opposite combination-Y. b. brevifolia flowers with Y. b. jaegeriana vegetative morphology-never occurred. Microsatellite genotyping revealed a high frequency of genetically admixed, hybrid trees. Coalescent-based estimates of migration indicated significant gene flow between the subspecies and that the direction of gene flow matches differences in pollinator host fidelity. The data suggest that pollinator behaviour determines the magnitude and direction of gene flow between the two subspecies, but that specialized pollination alone is not sufficient to maintain species boundaries. Natural selection may be required to maintain phenotypic differences in the face of ongoing gene flow.
Short-term and midterm results of an all-autogenous tissue policy for infrainguinal reconstruction.

Abstract Saphenous vein is the optimal conduit for infrainguinal vascular reconstruction. In instances in which this vein is unavailable or of "poor quality," reliance has been placed on a variety of prosthetic materials for bypass grafting. However, long-term patency with these prosthetic grafts has been disappointing. In January 1985 we instituted a policy of using exclusively autogenous tissue for infrainguinal arterial reconstruction. During the ensuing 3-year period, 203 patients underwent 266 arterial operations below the inguinal ligament, with a prosthetic graft used in only 11 instances (4%). No patient was denied surgery for limb salvage because of a lack of available autogenous vein. Thirty-three percent of procedures were performed for failure of prior revascularization and 73% for limb salvage. The 3-year cumulative primary patency rate for all autogenous procedures was 72%. Procedures were divided into those that used greater saphenous vein (patency 77%) vs autogenous alternatives such as bypass with arm vein or lesser saphenous vein, vein patch angioplasty, and endarterectomy (patency 64%). The operative mortality rate was 1.4% and the 3-year limb salvage rate was 89%. Autogenous infrainguinal reconstruction can be performed in almost every instance with acceptable results, suggesting that the need for prosthetic bypass grafts in the lower extremity is less than has been previously reported. (J Vasc Surg 1989;9:107–14.)
Error floors in digital mobile radio systems due to delay distortion

The authors analyze the performance degradation of digital mobile communication systems due to delay distortions caused by filter imperfections and/or propagation anomalies of the channel. The analysis makes use of the error floor, which is defined as the lowest bit error rate (BER) the system can achieve in a very high C/N operated system. In addition to the conventional raised cosine filters, the performance of 'cube' and 'double jump' transfer function filters is studied. The results show that in the presence of delay distortion, the cube and double jump filters cause less BER degradation than the raised cosine filter. It is demonstrated that the 'linear rolloff' filter, a special case of cube and double jump filters, has the best performance. Computer simulations of channels with group delay distortion confirm these results. >
Curriculum development in microelectromechanical systems in mechanical engineering

Curriculum development in microelectromechanical systems (MEMS) in the Mechanical Engineering and Applied Mechanics (MEAM) Department at the University of Michigan is presented. A course curriculum structure that integrates both mechanical and electrical engineering courses is proposed for mechanical engineering students. The proposed curriculum starts from undergraduate study and finishes at the Ph.D. level. Two new graduate-level MEMS courses are proposed: "Introduction to MEMS" for senior undergraduate students and entry-level graduate students and "Advanced MEMS" for graduate students. The first course has been experimentally taught at the University of Michigan for three years and the class assessments are summarized and analyzed in this paper. It is clear from the student responses that they are interested in taking courses in emerging technologies such as MEMS and more courses in the MEMS area should be offered. Future MEMS curriculum development and a new MEMS course for undergraduate-level students in the college of engineering are discussed.
Assessing Spatial Equity: An Evaluation of Measures of Accessibility to Public Playgrounds:

Geographical and political research on urban service delivery—who benefits and why—has proliferated during the past two decades. Overall, this literature is not characterized by a particular attention to the importance of method in drawing conclusions about spatial equity based on empirical studies. Specifically, there has been scant interest in the effect of geographic methodology on assessing the relationship between access and socioeconomic characteristics that are spatially defined. In this paper we take a spatial analytical perspective to evaluate the importance of methodology in assessing whether or not, or to what degree the distribution of urban public services is equitable. We approach this issue by means of an empirical case study of the spatial distribution of playgrounds in Tulsa, Oklahoma, relative to that of the targeted constituencies (children) and other socioeconomic indicators. In addition to the ‘traditional’ measure (count of facilities in an areal unit), we consider a potential measur...
An L-RNA Aptamer that Binds and Inhibits RNase

L-RNA aptamers were developed that bind to barnase RNase and thereby inhibit the function of the enzyme. These aptamers were obtained by first carrying out in vitro selection of D-RNAs that bind to the full-length synthetic D-enantiomer of barnase, then reversing the mirror and preparing L-RNAs of identical sequence that similarly bind to natural L-barnase. The resulting L-aptamers bind L-barnase with an affinity of ∼100 nM and function as competitive inhibitors of enzyme cleavage of D-RNA substrates. L-RNA aptamers are resistant to degradation by ribonucleases, thus enabling them to function in biological samples, most notably for applications in molecular diagnostics and therapeutics. In addition to the irony of using RNA to inhibit RNase, L-RNA aptamers such as those described here could be used to measure the concentration or inhibit the function of RNase in the laboratory or in biological systems.