cssi/SciSciGPT-SciSciNet huggingface dataset:
β(1–3)Glucan synthase of Neurospora crassa : Reaction sequence based on kinetic evidence

On the basis of the kinetic effects of substrate, activator, and inhibitors on β(1–3) glucan synthase activity ofNeurospora crassa, we propose the following reaction sequence for glucan synthesis. First, enzyme binds laminaribiose (activator), forming an enzyme-laminaribiose complex. Substrate (UDP-Glc) binding follows. UDP-Glc is hydrolyzed, releasing UDP, while the glucose residue remains associated with glucan synthase. The resulting enzyme-activator-glucose complex binds another UDP-Glc. It is likely that linear competitive inhibitors act at this step. Initial polymerization occurs, forming a disaccharide (which remains bound to glucan synthase) and UDP, which is released. The resulting enzyme-activator-disaccharide binds another UDP-Glc, and Glc is covalently added; further polymerization occurs by addition of Glc (from UDP-Glc) to the growing glucan chain, which remains associated with glucan synthase. Uncompetitive inhibitors are likely to affect enzyme activity at this step.
Emergent renal dysfunction with colistin pharmacotherapy.

Study Objective To evaluate the association between the administration of intravenous (IV) colistin and the emergence of renal dysfunction. Design A retrospective medical record review. Setting A tertiary care academic medical center. Patients A total of 174 critically ill patients who received at least one dose of IV colistin between 2004 and 2007. Measurements and Main Results The primary outcome was development of renal dysfunction, defined as an increase in serum creatinine of 50% or more during therapy or the initiation of renal replacement therapy (RRT), in patients who received at least one dose of colistin and were not already on RRT. The severity of renal dysfunction was further categorized by the RIFLE criteria. Demographic and clinical characteristics were analyzed by logistic regression for association with new renal dysfunction. A total of 174 patients were evaluated for renal dysfunction. Of these patients, 84 (48%) experienced renal dysfunction on colistin. On multivariate analysis, age in years (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01–1.05) and receipt of concurrent nephrotoxin(s) (OR 3.35, 95% CI 1.34–8.36) significantly increased the risk of developing renal dysfunction. Conclusion In this critically ill population, renal dysfunction occurred frequently and was associated with older age and receipt of nephrotoxins.
An experimental determination of transition limits in a vertical natural convection flow adjacent to a surface

This paper reports the results of an experimental investigation to determine transition mechanisms and limits in gases at high pressure levels. We sought also to refine further the parameters for transition, in particular the role of kinematic viscosity. In flow adjacent to a vertical uniform-flux surface in nitrogen, pressures to 16 atm were used. Both mean and disturbance quantities for the temperature and velocity fields were measured for various values of the heat flux, downstream location and ambient pressure level. Hot-wire and fine thermocouple probes were used. We found that the velocity and thermal fields remain closely coupled. Velocity, or fluid-dynamic, transition is immediately followed by thermal transition. Each was detected as a decrease in the rate of increase of both the maximum velocity and the overall temperature difference, respectively, from the laminar downstream trends. Also, the ends of transition for the velocity and the thermal fields, respectively, signalled by no further appreciable change in the intermittency distributions, were simultaneous. These results re-affirm the finding that the events of transition are not correlated by the Grashof number alone. An additional dependence on both downstream location and pressure level arises. A fixed value of the parameter , where Q is the fifth root of the local non-dimensional total heat convected in the boundary region. A re-examination of other transition studies, in both gases and liquids, supports these correlations, although many such data were not determined with fast response to local sensors. There remains a small level of uncertainty in establishing exact limits for transition, since the apparently proper standards for determining them are very difficult to apply precisely in experiments. However, such limits are very important in separating regimes of different transport mechanisms.
Wetting of Al 2 O 3 by molten aluminum: the influence of BaSO 4 additions

The effects of BaSO4 additions on the wetting of alumina by molten aluminum were studied by the sessile drop technique. To study the effect of BaSO4 decomposition (1100-1150°C), the additions were treated at two temperatures 700°C (973 K) and 1450°C (1723 K), respectively. BaSO4 additions at low and high temperatures did not improve the nonwetting character of these compositions. However, at higher firing temperature, the formation of BA6 (BaO•6Al2O3) has a nonwetting trend with increasing its content. To address the BA6 specifically a pure BaO•6Al2O3 was produced and tested. It was more nonwetting than the pure alumina. After the analysis of the contact angles for the BaSO4 and the BA6 (BaO•6Al2O3), it was concluded that these additions to alumina do not inhibit wetting by molten aluminum. In fact, at the addition levels common for refractories, the wetting tendency of molten aluminum is enhanced. Alternative explanations for the effectiveness of BaSO4 additions to alumina refractories are discussed.
Directed desorption as a probe of the structure of the desorption site

Abstract This paper attempts to assess the effects of surface structure on the angular variation of the desorption flux. Quantum calculations are done which show that if the gas-surface interaction potential is sufficiently corrugated in the neighborhood of the desorption site, and the adsorbate molecules desorb without going through a mobile precursor state, then they desorb preferentially in the direction of the surface normal. An activation barrier for adsorption need not be invoked. The predictions of the model agree with recent experiments. More theoretical and experimental verification of the model is needed, but it appears that it should be possible to use a directed desorption experiment to probe the forces on a molecule when it is about to desorb from a surface.
Dysregulation of the angiopoietin–Tie-2 axis in sepsis and ARDS

Dynamic changes in microvascular endothelial structure and function are pivotal in the acute inflammatory response, the body's rapid, coordinated effort to localize, sequester, and eliminate microbial invaders at their portal of entry. To achieve this, the endothelium becomes leaky and inflamed, providing innate immune cells and humoral effector molecules access to the site of infection. During sepsis this locally adaptive response becomes manifest throughout the body, leading to dangerous host consequences. Increased leakiness in the pulmonary circulation contributes to acute respiratory distress syndrome (ARDS), a complication of sepsis associated with 40% mortality. Understanding the molecular governance of vascular leak and inflammation has major diagnostic, prognostic, and potentially therapeutic implications for this common and pernicious disease. This review summarizes results from cell-based experiments, animal models, and observational human studies; together, these studies suggest that an endothelial receptor called Tie2 and its ligands, called angiopoietins, form a signaling axis key to the vascular dyshomeostasis that underlies sepsis.
Leadership Constraints: Leading Global Virtual Teams Through Environmental Complexity

This research focused on the question: What leadership constraints contribute to the complexity of the working environment faced by global virtual team leaders and how do those leadership constraints impact the behavior of leaders when they are trying to meet team member expectations? This qualitative study of a high performing team within a multinational corporation MNC identified four constraints facing leaders: virtuality, globalization, the domestic workplace, and the matrix organizational structure. These constraints and their interactions contributed to the complexity that leaders faced when attempting to influence followers. While work/life roles have changed dramatically for leaders, team member expectations remain rooted in the past.
TRH and Dopamine Interactions Affecting Pituitary Hormone Secretion

Dopamine infusion consistently elevated baseline serum growth hormone values in normal males in contrast to a suppression of baseline serum prolactin and perhaps TSH values. The mean peak serum TSH concentration in response to 100 fjig TRH was 14 ± 2 μU/ml in normal males and fell to 7 ± 2 μU/ml when a dopamine infusion was begun 5 min before the TRH bolus and continued for 120 minutes. Under similar conditions, the mean peak serum prolactin response (36 ± 3 ng/ml) was obliterated and was markedly attenuated when the dopamine infusion was begun 5 min after the TRH bolus (17 ± 2 ng/ml) (P < .01). Administration of 100 μg of T3 4 h previously resulted in a mean peak serum prolactin concentration of 46 ± 6 ng/ml in response to TRH ad ministered 5 min before a 60 min dopamine infusion, compared to 17 ± 2 ng/ml without triiodothyronine (P < .01). Serum growth hormone rose to a mean peak value of 13 ± 2 ng/ml at 60 min in response to dopamine from a mean baseline value of 1 ±0.1 ng/ml (P < .001). When 100 μg of...
Metal−Metal Multiply-Bonded Complexes of Technetium. 4.1 Photodissociation of the Tc≡Tc Triple Bond in [Tc2(CH3CN)10][BF4]4

Efficient (i.e., essentially quantitative) photolysis of multiple bonds, including metal-metal multiple bonds, neither is to be generally expected nor has been observed, with the sole exception of photocleavage of the quadruple bond in [Re{sub 2}Cl{sub 8}]{sup 2-}, which occurs in acetonitrile and affords ReCl{sub 3}(CH{sub 3}CN){sub 3} as the final product. We report here a striking example of such a process, wherein the [(CH{sub 3}CN){sub 5}Tc=Tc(CH{sub 3}CN){sub 5}]{sup 4+} ion is photolyzed in CH{sub 3}CN to give two [Tc(CH{sub 3}CN){sub 6}]{sup 2+} ions in nearly quantitative isolated yield. A plausible idea (admittedly not yet supported experimentally) is that photoexcitation produces a mixed-valent, charge-separated Tc(I)-Tc(III) complex that undergoes metal-metal bond cleavage to produce mononuclear Tc(I) and Tc(III) nitrile complexes. These mononuclear species could then undergo a comproportionation reaction to yield 2 consistent with the observed electrochemical potentials of the Tc(I)/Tc(II) and Tc(II)/Tc(III) redox couples. 17 refs., 2 figs.
Systematic Distorted-Wave Born-Approximation Predictions for Two-Nucleon Transfers: Applications to (d,α) Experiments

In the case of angular-momentum-mismatch conventional distorted-wave Born-approximation (DWBA) calculations tend to give results which are strongly dependent on the opticalmodel parameters chosen and, to a lesser degree, on finite-range and nonlocality effects. We discuss reasons for this sensitivity and present systematic calculations for ($d,\ensuremath{\alpha}$) reactions on nondeformed targets ranging from $^{48}\mathrm{Ti}$ to $^{208}\mathrm{Pb}$. Satisfactory DWBA results could be obtained for the entire range of targets, provided that all potentials for the generation of scattered and bound wave functions were restrained to have nearly identical physically meaningful real well geometries and real depths of $V\ensuremath{\approx}n{V}_{0}$, where ${V}_{0}$ is the proton scattering potential and $n$ is the number of nucleons in the projectile. The use of well geometries with ${r}_{0}=1.2$ fm, $a=0.75$ fm, and retention of the basic DWBA requirement that the optical potentials should also correctly fit elastic scattering removes the familiar ambiguities for deuteron and $\ensuremath{\alpha}$ potentials. It is shown that with these parameter restrictions finite range effects are expected to be small so that a first-order correction procedure is adequate. Explicit calculations are compared with over 30 ($d,\ensuremath{\alpha}$) angular distributions of known angular momentum transfer for experimental bombarding energies ranging from 12 to 17 MeV. Consistent agreement with experiment was obtained.
Robotic Surgery for Oropharynx Cancer: Promise, Challenges, and Future Directions

Epidemiologic studies have shown a rise in the incidence of oropharyngeal cancer without a corresponding increase in oral cavity cancers. These diverging trends are explained by human papilloma virus, which preferentially affects the oropharynx. Cancers resulting from this viral infection bear a better prognosis than those that are smoking-related. Treatment of oropharyngeal cancers has typically involved the use of radiation and chemotherapy to avoid the morbidity of mandibular splitting surgery. The use of transoral robotic surgery (TORS) has obviated the need for large-scale open approaches but still provides the pathologic staging data that is unavailable from non-surgical approaches. Although TORS is in its infancy, early functional and oncologic outcome data are promising. The complex management of oropharyngeal cancers should utilize the available treatment modalities to optimize outcomes and stratify patients to different treatment based on risk status.
Carbon decomposition kinetics and nitrogen mineralization from corn, soybean, and wheat residues

Abstract An incubation study was conducted for 30 days in Taloka (fine, mixed, thermic mollic Albaqualf) and Leadvale (fine, silty, siliceous, thermic typic Fragiudult) silt loam soils to evaluate carbon (C) and nitrogen (N) mineralization from soybean [Glycine max (L.) Merr.], corn (Zea mays L.), and wheat (Triticum aestivum L.) residues. Corn and soybean residues were collected at the tasseling and late vegetative stages, respectively. Wheat straw was collected after harvest. Carbon dioxide (CO2) evolution and inorganic N accumulation were measured. Carbon mineralization was described by a sequential decomposition model with a rapid and slow phase, each described by first‐order kinetics. Rapid and slow fraction rate constants and percent rapid were determined. Decomposition ranged from 39% for wheat to 67% for soybean. Carbon dioxide evolution peaked on the third day, and 30 to 50% of residue C was decomposed during the first six days of incubation. Decomposition and N mineralization were higher in the ...
Reproductive biology of the rare orchid, Spiranthes diluvialis: Breeding system, pollination, and implications for conservation

We examined the breeding system and pollination of Ute lady’s tresses, Spiranthes diluvialis Sheviak, a rare orchid from Colorado and Utah. S. diluvialis exhibits a mixed-mating system: the degree of selfing depends in part upon the abundance of pollinators visiting the flowers. Outcrossing is promoted by protandrous flowers and by acropetal movement of long-tongued bees on inflorescences. Male and female phases overlap, however, and flowers are fully self-compatible. No autogamous or agamospermous fruit set was observed, indicating that a pollen vector is required for reproduction. Observations indicate that bumblebees (Bombus spp.) are the most important pollinators of S. diluvialis. Land managers must include pollinators and pollen-producing plants in their plans to preserve this rare orchid. The effects of pest management programs on bumblebees and the availability of suitable bee nesting habitat should be considered. Management should strive to maintain floral diversity because other flowering species may facilitate S. diluvialis pollination. En el presente trabajo examinamos el sistema reproductivo y la polinizacion de Spiranthes diluvialis Sheviak, una orquidea rara de Colorado y Utah. S. diluvialis exhibe un sistema reproductivo mixto: el grado de autopolinizacion depende en parte de la abundancia de los polinizadores que visitan las flores. La exocria es promovida por flores protandricas y por movimientos acropetalos de abejas en las inflorecencias. Sin embargo, las fases femenina y masculina se superponen y las flores son totalmente autocompatibles. No se observaron frutos autogamos o agamospermos, lo que indica que se requiere un vector de polen para la reproduccion. Las observaciones indican que los abejorros (Bombus spp.) son los polinizadores mas importantes de S. diluvialis. Los encargados del manejo de tierras, deben incluir a los polinizadores y plantas productoras de polen en sus planes para preserva esta rara orquidea. Se deberian considera los efectos de los programas de manejo de pestes sobre los abejorros y la disponibilidad de habitat apropiado para el anidamiento de abejas. El manejo deberia centrar sus esfuerzos para mantener la diversidad floristica, ya que otras especies con flores podrian facilitar la pollinizacion de S. diluvialis.
Lexical representation and development in a second language

A psycholinguistic model of vocabulary acquisition in a second language (L2) in instructional settings is outlined in this paper. Considered in light of how the lexical entries in the L2 lexicon evolve, L2 vocabulary acquisition is seen as consisting of three stages: the formal stage when a lexical entry with formal specifications is established, the first language (Ll) lemma mediation stage when the lemma information of the LI counterpart is copied into the L2 lexical entry and mediates L2 word use, and the L2 integration stage when semantic, syntactic, morphological specifications are integrated into the lexical entry. It is argued that due to the practical constraints imposed on L2 learning, a majority of L2 words fossilize at the second stage. Thus, lexical representation in L2 in general has three unique features: (a) a lexical entry consists of L2 lexeme and L1 lemma; (b) little morphological specifications are integrated within the entry; (c) the links between L2 words and concepts are weak. The processing consequences of these features, relevant research evidence in support of this model, and its implications for L2 vocabulary acquisition research are discussed
Endothelial progenitor populations in differentiating embryonic stem cells I: Identification and differentiation kinetics.

Embryonic stem cells (ESCs) have enormous potential in tissue engineering and cell therapies. However, the therapeutic use of ESCs has been restricted because of the presence of undifferentiated cells or cells with undesired phenotypes. We have explored identifying and selecting endothelial cells (ECs) using green fluorescent protein (GFP) under the control of different endothelial promoters. This method can result in progenitor populations that differ based on promoter activity; however, there have not been rigorous studies comparing differentiation kinetics and selection using these promoters as well as the resulting phenotype. In this study, we examined differentiation profiles of ESCs selected using three different endothelial promoters (Flk1, PECAM, and Tie1) that correspond to endothelial proteins expressed at different time points (early, middle, and late) in ESC differentiation. All three promoters yielded cells with EC-specific protein expression and DiI-Ac-LDL uptake when sorted for GFP+ populat...
The relationship of graphite/AsF5 intercalation compounds to Cx+AsF6− salts

Abstract Graphite intercalated by AsF 5 has been reported to give compounds of formula C 8n AsF 5 where n is the stage. It is doubtful however if materials of exact composition C 8n AsF 5 have ever been obtained. The intercalation of graphite by AsF 5 is associated with electron oxidation of the graphite according to the equation: 3AsF 5 + 2e − → 2AsF 6 − + AsF 3 . Because of the easy removal or displacement of AsF 3 the As:F ratio is readily increased beyond 5. By treating graphite with excess AsF 5 , removing volatiles under vacuum and repeating the cycle seven times a first stage salt C 10 + AsF 6 − (C o = 7.96 Ā) is made. Interaction of graphite with AsFs in the molar ratio 8:1, within a small volume reactor, yields a material of approximate composition C 8 AsF 5 . The major component of the volatiles at the onset of their removal is AsF 5 ,, but, at a composition close to C 10 AsF 5 , is AsF 3 . ‘Graphite AsF 5 ’ can be prepared by adding AsF 3 to C x AsF 6 salts. The electrical conductivities of ‘AsF 5 ’ and AsF 6 relatives will be compared and discussed.
The clinical application of dynamic shielding and imaging in moving table total body irradiation

The moving table technique for total body irradiation (MTT TBI) has some advantages in regard to dose homogeneity, patient positioning and comfort. However, divergence of the radiation field coupled with patient motion necessitates corresponding motion of the shielding blocks and verification film so that penumbra is minimized. MTT TBI system is presented, together with dose calculations, incorporating moving trays for shields and film to ensure dose delivery with minimal penumbra of the blocked field.
Stepwise translocation of Dpo4 polymerase during error-free bypass of an oxoG lesion

7,8-dihydro-8-oxoguanine (oxoG), the predominant lesion formed following oxidative damage of DNA by reactive oxygen species, is processed differently by replicative and bypass polymerases. Our kinetic primer extension studies demonstrate that the bypass polymerase Dpo4 preferentially inserts C opposite oxoG, and also preferentially extends from the oxoG•C base pair, thus achieving error-free bypass of this lesion. We have determined the crystal structures of preinsertion binary, insertion ternary, and postinsertion binary complexes of oxoG-modified template-primer DNA and Dpo4. These structures provide insights into the translocation mechanics of the bypass polymerase during a complete cycle of nucleotide incorporation. Specifically, during noncovalent dCTP insertion opposite oxoG (or G), the little-finger domain–DNA phosphate contacts translocate by one nucleotide step, while the thumb domain–DNA phosphate contacts remain fixed. By contrast, during the nucleotidyl transfer reaction that covalently incorporates C opposite oxoG, the thumb-domain–phosphate contacts are translocated by one nucleotide step, while the little-finger contacts with phosphate groups remain fixed. These stepwise conformational transitions accompanying nucleoside triphosphate binding and covalent nucleobase incorporation during a full replication cycle of Dpo4-catalyzed bypass of the oxoG lesion are distinct from the translocation events in replicative polymerases.
Electromechanical behavior of [001]-textured Pb(Mg1/3Nb2/3)O3-PbTiO3 ceramics

[001]-textured Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) ceramics were synthesized by using templated grain growth method. Significantly high [001] texture degree corresponding to 0.98 Lotgering factor was achieved at 1 vol. % BaTiO3 template. Electromechanical properties for [001]-textured PMN-PT ceramics with 1 vol. % BaTiO3 were found to be d33 = 1000 pC/N, d31 = 371 pC/N, ɛr = 2591, and tanδ = ∼0.6%. Elastoelectric composite based modeling results showed that higher volume fraction of template reduces the overall dielectric constant and thus has adverse effect on the piezoelectric response. Clamping effect was modeled by deriving the changes in free energy as a function of applied electric field and microstructural boundary condition.
Information processing speed deficits may be better correlated with the extent of white matter sclerotic lesions in multiple sclerosis than previously suspected.

Despite frequent use of the Paced Auditory Serial Addition Test (PASAT; Gronwall, 1977) for examining information processing speed (IPS) deficits in multiple sclerosis (MS), prior literature on the relationship between PASAT performance and severity of brain disease has been contradictory. In the present study, we found that PASAT performance is moderately well correlated with the total area of sclerotic brain lesions in MS patients only if a modified scoring method (mean “dyad” score; Snyder et al., 1993), but not the standard scoring method, is applied. We conclude that the PASAT remains a useful measure of IPS in MS, if a flaw in the typical scoring technique for this test is corrected. In our sample of 41 MS patients, for every one point decrease in mean dyad score, total lesion area increased by 364.08 mm= on average, after controlling for age, sex, and education. IPS deficits are more severe for patients with greater brain disease, due to increased disruption of the white matter pathways that likely support the parallel distributed processing of complex information by geographically distant brain regions.
Enhanced Sensitivity to Slow Motions Using 15N-Nitroxide Spin Labels

Abstract The rotational motion of an 15N nitroxide in diisobutylphthalate solutions at varied temperatures has been studied for correlation times from 10−8 to > 10−3 sec. Data from both conventional (first-harmonic, in-phase) and saturation-transfer (second-harmonic, out-of-phase) EPR are reported. For many spectral parameters, including linewidth, position of outer extrema, and ratios of spectral amplitudes in saturation transfer spectra, the 15N-nitroxide signals are sensitive to the same range of motions as are 14N-nitroxide spectra, but the 15N data offer the convenience of enhanced signal amplitude. In addition, the peak-to-peak separation of the low-field signal of 15N nitroxides in the conventional V1 display has a smooth dependence on rates of motion from 107 to 104 sec and is measured in the most intense regions of the spectrum.
On the Impact of HDLC Zero Insertion and Deletion on Link Utilization and Reliability

In HDLC, a zero is inserted after every five consecutive "ones" in order to resolve ambiguity about the location of delimiters. In this paper, we generalize the number "five" as an arbitrary positive integer n and study the impacts of n on the link utilization for a noiseless channel and on the reliability for a noisy channel. The entropy of the sequence after this generalized zero insertion is found for a noiseless channel. An expression for the optimal n that maximizes a quantity called the delimiter efficiency is also found in terms of the frame size. It is shown that n = 5 achieves a delimiter efficiency close (within 2 percent) to that achievable by the optimal n . For a noisy channel, the reliability of HDLC is derived. It is shown that the probability of an undetectable error in HDLC is dominated by the errors that propagate through a created flag or incorrect zero deletion, and is in the neighborhood of 10-7for typical parameters. Increasing n by 8 is shown to improve the reliability by two orders of magnitude. It is proposed to use a two byte flag and a four byte frame check sequence to improve the reliability by seven orders of magnitude.
Comment on 'Modeling and analysis of a bimorph piezoelectric cantilever beam for voltage generation'

In a recent paper, Ajitsaria et al (2007 Smart Mater. Struct. 16 447–54) presented a mathematical formulation for the modeling and analysis of a bimorph piezoelectric cantilever beam for voltage generation. Their motivation was the recent increasing trend in using the piezoelectric effect to harvest electrical energy from ambient vibrations. This comment addresses the modeling errors and numerous undefined and missing terms in the mentioned work.
Lineshape of magnetization transfer via cross relaxation

Magnetization transfer, a well-known technique in NMR ( 1) , has recently become of interest in magnetic resonance imaging. This is largely due to the discovery by Wolf and Balaban that a new form of tissue-specific contrast, which they refer to as magnetization-transfer contrast (MTC), can be generated with the technique (2). While the detailed mechanism for MTC is an area of active research, current consensus is that the contrast is generated through cross relaxation between protons in the mobile water and immobile protons in macromolecules (3). Magnetization transfer is usually observed by RF irradiation at an offset frequency which results in the partial saturation of immobile protons in macromolecules and minimal energy absorption by the mobile water. Subsequently, the cross relaxation between the mobile and immobile protons results in a reduction of the longitudinal magnetization 44, on the mobile water protons. Although For&n and Hofhnan (I ) and Mann (4) derived formulas relating the mobile water M, reduction to the crossrelaxation rate constant in the 1960s and 1970s respectively, their formulas do not describe the functional dependence of magnetization transfer on offset frequency and RF irradiation power. Experimental results indicate that the magnitude of the magnetization-transfer effect can be controlled by these factors (2). A theoretical understanding of the problem is of fundamental importance to applications of the technique and should be especially useful in MRI applications. Recently, Grad and Bryant derived an expression for the cross-relaxation spectroscopy lineshape, from which one can determine the effect of offset frequency and RF irradiation power on magnetization transfer (5). However, they employed a truncated set of the coupled Bloch equations, and their results are valid only if the transverse magnetization of mobile water spins is negligible. This assumption may not be met in MRI experiments where the offset frequency is relatively small or where the RF irradiation power is large. In these cases Grad and Bryant’s lineshape expression will overestimate the degree of magnetization transfer. In the present work, a complete set of coupled Bloch equations is used to obtain the cross-relaxation spectroscopy lineshape. The result is more general than Grad and Bryant’s and reduces to their expression when the transverse magnetization of mobile water spins is negligible. The coupled Bloch equations for two cross-relaxed spins (e.g., via the dipole-dipole coupling) are
Rehabilitation Following Turf Toe Injury and Plantar Plate Repair

The evaluation and diagnosis of turf toe injuries is improving as it becomes a more recognized pattern of injury to the hallux metatarsophalangeal joint. With an understanding of the anatomy of the injury and the ability to focus on important diagnostic and radiographic clues, turf toe can be diagnosed, assessed, and treated accurately, with surgical repair when indicated. Regardless of the grade of injury, rehabilitation of the athlete under the guidance of a physical therapist or athletic trainer is critical to complete recovery. With appropriate care, athletes can successfully return to play and efficiently reach their preinjury level of participation.
Preliminary paleomagnetic poles and correlation of the Proterozoic Uinta Mountain Group, Utah and Colorado

Abstract Stable paleomagnetic directions have been obtained from seven sites spanning much of the 7-km-thick middle Proterozoic Uinta Mountain Group. The characteristic magnetization is carried partly by detrital(?) and secondary specularite and partly by hematite pigment. Preliminary paleomagnetic poles for six of the seven sites are closely grouped and their mean pole is 0.6°N, 157.2°E (N = 6, α95 = 5.4°). The pole for the seventh and stratigraphically highest site lies to the west, 4.6°N, 140.1°E, and (n = 8, α95= 15.9°). On the basis of the poles, revisions to correlations of the Uinta Mountain Group with other sequences are proposed. The Uinta Mountain Group appears to correlate with the Chuar Group and perhaps the upper member of the underlying Nankoweap Formation, and post-dates the Unkar Group of the Grand Canyon Supergroup. In addition, the upper part of the Uinta Mountain Group appears to correlate with the Little Dal Group of the Northwest Territories, Canada. The Uinta Mountain Group appears to entirely post-date the Belt Supergroup of Montana and Idaho. Correlation of the Uinta Mountain Group with the Chuar and Little Dal Groups is supported by the presence of the fossil Chuaria and by apparently overlapping isotopic ages. A maximum age range for the Uinta Mountain Group, extrapolated from the Grand Canyon Supergroup and the Little Dal Group, extends from 770 m.y.
Li–Yorke sensitivity for semigroup actions

We introduce and study the concept of Li–Yorke sensitivity for semigroup actions (dynamical systems of the form (X, G), where X is a metric space and G is a semigroup of continuous mappings of this space onto itself). A system (X, G) is called Li–Yorke sensitive if there exists positive e such that, for any point x ∈ X and any open neighborhood U of this point, one can find a point y ∈ U for which the following conditions are satisfied: (i) d(g(x), g(y)) > e for infinitely many g ∈ G, (ii) for any δ > 0; there exists h ∈ G satisfying the condition d(h(x), h(y)) < δ. In particular, it is shown that a nontrivial topologically weakly mixing system (X, G) with a compact set X and an Abelian semigroup G is Li–Yorke sensitive.
Diel trend in plant sensitivity to ozone: Implications for exposure- and flux-based ozone metrics

Abstract Plant sensitivity to ozone (O 3 ) is critical to modeling impacts of air pollution on vegetation. A diel timecourse of sensitivity ( S ) was recently determined in Pima cotton (Grantz et al., 2013). The sensitivity parameter serves as a weighting factor for stomatal uptake (ozone flux, F ), or cumulative F (dose, D ). Previous approaches used various weighting schemes to modify ozone concentration ([O 3 ]) or cumulative [O 3 ] (exposure, E ). Use of the S parameter allows calculation of effective flux ( F eff ) and effective dose ( D eff ). Though theoretically sound, the practical significance of S has not been evaluated due to the previous lack of available data. Here, the newly available S parameter is used to explore the relationships between exposure- and flux-based O 3 metrics in response to scenarios of contrasting stomatal conductance ( g s ) and ambient [O 3 ]. The O 3 scenarios were similar but differed in timing of peak [O 3 ]. E varied by up to 13.7%, D by up to 15.4%, and D eff , which factors in sensitivity, by up to 19.0%. The g s scenarios differed in midday magnitude and nocturnal closure. Cumulative g s varied by 65.2%, which was attenuated in D to 49.2% and in D eff to 51.1%. A simulation of hourly [O 3 ], F , and F eff was run using Monte Carlo techniques with a full month of ambient [O 3 ] data. Resulting diel timecourses of [O 3 ], F , and F eff were realistic, with the principal sources of uncertainty in the physiological parameters, g s and S . Analysis of hourly values from the scenarios and the simulation output demonstrated significant correlation among the O 3 metrics. However, the uncertainty in both F and F eff predicted from [O 3 ] was large and proportional to [O 3 ], yielding greatest uncertainty under conditions of high [O 3 ] and potential phytotoxicity. In contrast, F eff was significantly correlated with F , with low variability that was not proportional to F . As a result, uncertainty was low and prediction potentially useful under conditions of likely injury. These results suggest that F, which incorporates g s , represents a substantial improvement over ambient [O 3 ], which does not. F eff , which incorporates S, was closely related to F , which does not use S. The substantial effort required to measure or model S and F eff may not be justified under some conditions. Further research to obtain additional timecourses of S and to explore additional [O 3 ] and g s scenarios is urgently required.
Lysis of enucleated tumor cells with allogeneic and syngeneic cytotoxic thymus-derived lymphocytes.

These studies were initiated to understand the minimal requirements for lysis of target cells by cytotoxic thymus-derived lymphocytes (CTL). In particular, the significance of the nucleus to the susceptibility of the target cell to be lysed by CTL have been studied. P815 mastocytoma cells and EL4 lymphoma cells were enucleated by cen- trifugation through a discontinuous Ficoll gradient containing 10 μg/ml of cytochalasin B. The resultant vesicles were then analyzed for susceptibility to lysis by different CTL specific for the H-2K and H-2D gene products, minor histocompatibility antigens, trinitrophenyl groups, and Sendai virus-specific antigens. The results indicate that enucleated vesicles obtained from both EL 4 and P 815 cells are susceptible to lysis by these CTL. The lysis of EL 4-enucleated vesicles (unlike P 815-enucleated vesicles), however, required 2–4 times more effector cells than were required for equivalent lysis of intact EL 4 cells. This reduced susceptibility to lysis of enucleated EL 4 vesicles was not the result of an inability of the CTL to recognize and bind the vesicles. This conclusion was suggested by the fact that both enucleated EL 4 vesicles and intact cells inhibited equally well the lysis of 51Cr-labeled concanavalin A-stimulated BALB. B spleen cells by anti-H-2b CTL. Although enucleated vesicles obtained from both P 815 and EL 4 cells were susceptible to lysis by CTL, they exhibited a reduced capacity to “cap” their serologically defined H-2 antigens. Lysis of these enucleated vesicles by CTL has the same requirements as lysis of intact cells. This conclusion was based upon the requirement for Ca++ and Mg++ and also because lysis of the modified vesicles (trinitrophenyl or viral antigens) occurred in an H-2-restricted fashion. Moreover, the enucleated vesicles were susceptible to antibody and complement-mediated lysis and also lectin-dependent cell-mediated cytotoxicity.
Residential segregation in new Hispanic destinations: Cities, suburbs, and rural communities compared

Abstract This paper provides new estimates of Hispanic–white residential segregation in new destinations and established Hispanic places. New Hispanic destinations are defined broadly to include metropolitan cities, suburban places, and rural communities with unusually rapid Hispanic growth rates. The analysis is framed with the spatial assimilation and place stratification perspectives and is based on block data from the 1990 and 2000 decennial censuses. The analysis confirms our basic hypothesis – that Hispanics are highly segregated in new Hispanic destinations, often at levels greatly exceeding those in established places. Hispanic suburbanization or exurbanization into new destinations is no marker of spatial assimilation. Consistent with the place stratification perspective, differences in Hispanic–white segregation between new destinations and established Hispanic areas cannot be explained by place-to-place differences in ecological location, population composition, economic growth, employment, or Hispanic–white income inequality. Hispanic segregation in new destinations is especially sensitive to the size of the foreign-born population and to preexisting “minority threats” in communities with large black populations. Segregation levels in new destinations also are less responsive to income disparities between Hispanics and whites; economic assimilation does not insure Hispanic spatial assimilation. Understanding how newcomers are spatially incorporated in new destinations will be a continuing challenge for scholars concerned about the spatial diffusion and apparent geographic balkanization of America’s growing Hispanic population.
Sequence and phylogenetic analyses of 4 TMS junctional proteins of animals: Connexins, innexins, claudins and occludins

Connexins and probably innexins are the principal constituents of gap junctions, while claudins and occludins are principal tight junctional constituents. All have similar topologies with four α-helical transmembrane segments (TMSs), and all exhibit well-conserved extracytoplasmic cysteines that either are known to or potentially can form disulfide bridges. We have conducted sequence, topological and phylogenetic analyses of the proteins that comprise the connexin, innexin, claudin and occludin families. A multiple alignment of the sequences of each family was used to derive average hydropathy and similarity plots as well as phylogenetic trees. Analyses of the data generated led to the following evolutionary and functional suggestions: (1) In all four families, the most conserved regions of the proteins from each family are the four TMSs although the extracytoplasmic loops between TMSs 1 and 2, and TMSs 3 and 4 are usually well conserved. (2) The phylogenetic trees revealed sets of orthologues except for the innexins where phylogeny primarily reflects organismal source, probably due to a lack of relevant organismal sequence data. (3) The two halves of the connexins exhibit similarities suggesting that they were derived from a common origin by an internal gene duplication event. (4) Conserved cysteyl residues in the connexins and innexins may point to a similar extracellular structure involved in the docking of hemichannels to create intercellular communication channels. (5) We suggest a similar role in homomeric interactions for conserved extracellular residues in the claudins and occludins. The lack of sequence or motif similarity between the four different families indicates that, if they did evolve from a common ancestral gene, they have diverged considerably to fulfill separate, novel functions. We suggest that internal duplication was a general evolutionary strategy used to generate new families of channels and junctions with unique functions. These findings and suggestions should serve as guides for future studies concerning the structures, functions and evolutionary origins of junctional proteins.
Plastic deformation of high-purity α-titanium: Model development and validation using the Taylor cylinder impact test

Abstract In this paper, results of an experimental study on the quasi-static and high-rate plastic deformation due to impact of a high-purity, polycrystalline, α-titanium material are presented. It was found that the material is transversely isotropic and displays strong strength differential effects. Split Hopkinson Pressure Bar tests in tension and compression and Taylor impact tests were conducted. For an impact velocity of 196 m/s, plastic deformation extended to 64% of the length of the deformed specimen, with little radial spreading. A three-dimensional constitutive model was developed. Key in the formulation was the use of a macroscopic yield function that incorporates the specificities of the plastic flow, namely the combined effects of anisotropy and tension–compression asymmetry. Comparison between model predictions and data show the capabilities of the model to describe with accuracy the plastic behavior of the α-titanium material for both quasi-static and high-rate loadings. In particular, the three-dimensional simulations of the Taylor impact test show a very good agreement with data, both the post-test major and minor side profiles and impact interface footprints are very well described.
Trichinella spiralis: nonspecific resistance and immunity to newborn larvae in inbred mice.

The implantation and development of intravenously injected Trichinella spiralis newborn larvae were examined in different strains of inbred mice by determining muscle larvae burden. This was compared to the numbers of muscle larvae that established after a natural infection during which a quantitative assessment of intestinal newborn larvae production was made. In most inbred strains of mice, newborn larvae do not all successfully implant in muscle. Mice of the DBA/1 strain are the most resistant to successful implantation, and C3H mice are the most permissive. This pattern is evident in the strains studied whether newborn larvae are injected intravenously or are produced by intestinal adults. Thus, after a natural infection, 100% of intestinally produced newborn larvae implanted in C3H mice, whereas in NFR 68% and DBA/1 mice 62% successfully matured in muscle. Immunity to newborn larvae could be demonstrated as early as 10 days after exposure to this stage of the life cycle. This immunity was protective against a complete challenge infection given 9 days after newborn larvae had been injected intravenously. Protection against newborn larvae was identical in male and female mice or in mice from 1 to 9 months of age. We conclude that there are two mechanisms by which mice impair newborn larvae establishment or development in muscle. The first appears to be nonimmunological (non-specific resistance), and the second is immunological. Genetically determined variation in strain-specific expression is apparent with both mechanisms. In strains displaying high intrinsic "resistance" (DBA/1), this process is likely to account for most of the 38% reduction in newborn larvae establishment in a primary infection. However, immunity against newborn larvae develops quickly enough to have a significant effect on migratory larvae in primary infections where adults persist in the intestine (e.g., the B10 congenic mice), or when high adult worm burdens delay adult worm rejection. Muscle larvae burden, therefore, reflects systemic nonspecific resistance to newborn larvae as well as immunological processes that occur in the intestine and systemically.
Mammalian target of rapamycin complex 1 (mTORC1) plays a role in Pasteurella multocida toxin (PMT)-induced protein synthesis and proliferation in Swiss 3T3 cells.

Pasteurella multocida toxin (PMT) is a potent mitogen known to activate several signaling pathways via deamidation of a conserved glutamine residue in the α subunit of heterotrimeric G-proteins. However, the detailed mechanism behind mitogenic properties of PMT is unknown. Herein, we show that PMT induces protein synthesis, cell migration, and proliferation in serum-starved Swiss 3T3 cells. Concomitantly PMT induces phosphorylation of ribosomal S6 kinase (S6K1) and its substrate, ribosomal S6 protein (rpS6), in quiescent 3T3 cells. The extent of the phosphorylation is time and PMT concentration dependent, and is inhibited by rapamycin and Torin1, the two specific inhibitors of the mammalian target of rapamycin complex 1 (mTORC1). Interestingly, PMT-mediated mTOR signaling activation was observed in MEF WT but not in Gαq/11 knock-out cells. These observations are consistent with the data indicating that PMT-induced mTORC1 activation proceeds via the deamidation of Gαq/11, which leads to the activation of PLCβ to generate diacylglycerol and inositol trisphosphate, two known activators of the PKC pathway. Exogenously added diacylglycerol or phorbol 12-myristate 13-acetate, known activators of PKC, leads to rpS6 phosphorylation in a rapamycin-dependent manner. Furthermore, PMT-induced rpS6 phosphorylation is inhibited by PKC inhibitor, Go6976. Although PMT induces epidermal growth factor receptor activation, it exerts no effect on PMT-induced rpS6 phosphorylation. Together, our findings reveal for the first time that PMT activates mTORC1 through the Gαq/11/PLCβ/PKC pathway. The fact that PMT-induced protein synthesis and cell migration is partially inhibited by rapamycin indicates that these processes are in part mediated by the mTORC1 pathway. Background: Pasteurella multocida toxin (PMT) is a highly mitogenic bacterial protein whose detailed mechanism is not well understood. Results: PMT deamidates and activates Gαq/11 leading to mTORC1 activation. Conclusion: Gαq/11/PLCβ/PKC-mediated mTORC1 activation is at least partially responsible for PMT-induced cell growth, migration, and proliferation in Swiss 3T3 cells. Significance: Understanding PMT-induced mTORC1 activation could help elucidate mechanisms of oncogene regulation.
Harnessing calcineurin as a novel anti-infective agent against invasive fungal infections

The number of immunocompromised patients with invasive fungal infections continues to increase and new antifungal therapies are not keeping pace with the growing incidence of these infections and their associated mortality. Calcineurin inhibition is currently used to exert effective immunosuppression following organ transplantation and in treating various other conditions. However, the calcineurin pathway is also intricately involved in the growth and pathogenesis of the three major fungal pathogens of humans, Cryptococcus neoformans, Candida albicans and Aspergillus fumigatus, and the exploitation of fungal calcineurin pathways holds great promise for the future development of novel antifungal agents. This Review summarizes our current understanding of calcineurin biology in these fungal species, and its exciting potential role in treating invasive fungal infections.