cssi/SciSciGPT-SciSciNet huggingface dataset:
Differences between membranoproliferative glomerulonephritis types I and III in long-term response to an alternate-day prednisone regimen

Membranoproliferative glomerulonephritis (MPGN) is classified as type I, II, or III based on ultrastructural alterations in the glomerular basement membrane. Whereas type II has long been recognized as clinically and pathologically unique, types I and III are often difficult to distinguish and have not been separated in most clinical studies. We compared the course and long-term outcome of patients with types I and III MPGN followed up at this institution since 1960. During this period, 21 patients with type I and 25 patients with type III were followed up for a minimum of 5 years. Patients with types I and III MPGN did not differ in age at apparent onset, age at diagnosis, or interval from apparent onset of symptoms to diagnosis (biopsy). They had similar initial serum C3 and serum albumin levels. Patients with type I had a significantly lower initial mean estimated glomerular filtration rate (GFR(est)) compared with those with type III (99.1 +/- 35.9 versus 131.6 +/- 36. 1 mL/min/1.73 m(2); P < 0.01). Type and duration of therapy, length of follow-up, and frequency of complications of therapy did not differ between groups. There was, however, a significant difference in duration of hypocomplementemia. After 1 year of an alternate-day prednisone regimen, 90% of the type I patients normalized their serum C3 levels compared with less than 50% of type III patients (P < 0.01). After 3 years of therapy, only 5% of type I patients were hypocomplementemic compared with 33% of type III patients (P < 0.02). In addition, disease relapse occurred in six type III patients (24%) compared with no type I patients. At last follow-up, type I patients had a slight improvement in mean GFR(est) (+6.3 +/- 48.4 mL/min/1.73 m(2)), whereas type III patients had a 25% decrease in mean GFR(est) (-34.8 +/- 47.6 mL/min/1.73 m(2); P < 0.01). Residual urinary abnormalities were significantly more frequent in patients with type III than type I MPGN. Hematuria persisted in 72% versus 38% (P < 0.05) and proteinuria in 28% versus 0% (P < 0.01) of those with types III and I, respectively. These results give clear evidence of significant differences in the clinical progression of the two types and their response to the alternate-day prednisone regimen. Whereas the outcome of patients with type I MPGN treated with alternate-day prednisone was generally good, similarly treated patients with type III experienced significant reductions in renal function, slower improvement in serum C3 levels, more persistent urinary abnormalities, and more frequent relapses.
On the geometric quantization of contact manifolds

Abstract Suppose that ( M , E ) is a compact contact manifold, and that a compact Lie group G acts on M transverse to the contact distribution E . In an earlier paper, we defined a G -transversally elliptic Dirac operator ⁄ D b , constructed using a Hermitian metric h and connection ∇ on the symplectic vector bundle E → M , whose equivariant index is well-defined as a generalized function on G , and gave a formula for its index. By analogy with the geometric quantization of symplectic manifolds, the virtual G -representation Q ( M ) = [ ker ⁄ D b ] − [ ker ⁄ D b ∗ ] can be interpreted as the “quantization” of the contact manifold ( M , E ) ; the character of this representation is then given by the equivariant index of ⁄ D b . By defining contact analogues of the algebra of observables, prequantum line bundle and polarization, we further extend the analogy by giving a contact version of the Kostant–Souriau approach to quantization, and discussing the extent to which this approach is reproduced by the index-theoretic method.
Application of microwave fixation techniques in pathology to neuroscience studies: a review

The introduction of microwave energy into the scientist's repertoire of fixation modalities offers for the first time in relatively large specimens the potential for 'instantaneous' preservation of cellular structure for light and electron microscopy with minimal alteration of cellular biochemistry and antigenicity. Because of the rapid evolution of this new technology, we provide a classification system of newly generated microwave methods as applied to specimen preservation for microscopic analysis. With emphasis on neuronal tissue, we review qualitative and quantitative microscopy data of specimens fixed by two microwave methods in common use: (1) microwave stabilization and (2) fast and ultrafast, primary microwave-chemical fixation. In addition, we provide a table of neuropeptides or proteins in neuronal tissues that are preserved by various microwave fixation methods for histochemistry, immunohistochemistry, and immuno-electron microscopy studies. Commercial microwave ovens have limitations which can result in irreproducible fixation results. Therefore, we present a calibration protocol that is used to identify the best locations for fixation within large cavity (i.e., household) microwave ovens. We also provide a standardization protocol to improve the reproducibility of microwave fixation in calibrated, large-cavity microwave ovens.
Enhanced synthesis and reduced metabolism of endothelin-1 (ET-1) by hepatocytes--an important mechanism of increased endogenous levels of ET-1 in liver cirrhosis.

Abstract Background/Aims: Hepatic concentration of endothelin-1 (ET-1) is increased in human and experimental liver cirrhosis. Because of its potent actions in the liver, ET-1 has been suggested to play an important role in the pathophysiology of cirrhosis. Since hepatocytes are the major cell type to metabolize ET-1, we investigated whether their reduced capacity to degrade ET-1 is a mechanism of its elevated levels in cirrhosis. Methods: The expression of ET-1 receptors, ET-1 and endothelin converting enzyme (ECE), and metabolism of ET-1 and ECE activity were compared in hepatocytes isolated from control and carbon tetrachloride-induced cirrhotic rats. Results: ET-1 receptor density and receptor-mediated internalization of ET-1 were significantly increased in cirrhotic hepatocytes relative to the control cells. However, compared to control hepatocytes, metabolism of ET-1 by the cirrhotic cells was reduced significantly. Interestingly, hepatocytes were found to contain preproET-1 mRNA, ECE-1 mRNA and ET-1. PreproET-1 mRNA and ET-1 levels were increased in cirrhotic hepatocytes but their ECE mRNA and ECE activity were not altered. Conclusions: These results provide the first evidence that hepatocytes have the ability to synthesize ET-1 and demonstrate that decreased metabolism and enhanced synthesis of ET-1 in hepatocytes are an important mechanism of its elevated levels in cirrhosis.
Oral feeding outcomes in neonates with congenital cardiac disease undergoing cardiac surgery.

BackgroundAchievement of adequate oral nutrition is a challenging task after early neonatal cardiac surgery. This study aims to describe predictors of oral feeding outcomes for neonates after early surgical interventions.Materials and methodsA retrospective review of neonates admitted with congenital cardiac disease over a period of 1 year. We analysed predictors of the need for a feeding tube at discharge and the amount taken at each feeding. Multilevel modelling was used to look at individual change over time predicting oral amount at each feeding.ResultsWe identified 56 neonates. Diagnoses were heterogeneous; 23% of the infants had associated genetic syndromes and 45% required pre-operative mechanical ventilation. The median time from birth to surgery was 8.4 days, with 29 infants fed orally before surgery. The mean time from surgery to first oral feeding attempt was 12 hours. Time from surgery to oral feeding, the amount taken with first feeding, and cross-clamp times were significant predictors of oral feeding success, whereas the presence of a comorbidity – genetic abnormality – and longer ventilator dependency predicted failure. Almost half of the neonates required a feeding tube upon discharge, and no infant discharged was solely breastfed. Discharge with a feeding tube was associated with greater weight gain at that time.ConclusionsNeonates with congenital cardiac disease face significant barriers to successfully achieving oral feeding on hospital discharge. Enteral feeding guidelines focus on physiological stabilisation and do not always address the developmental milestones necessary to support oral feeding. Future prospective studies are necessary to identify multimodal strategies to optimise early feeding.
Fabrication of Dense Zirconia Electrolyte Films for Tubular Solid Oxide Fuel Cells by Electrophoretic Deposition

Electrophoretic deposition (EPD) is used to produce zirconia electrolyte films for tubular solid oxide fuel cells. A simple suspension chemistry (8-mol%-yttria-stabilized zirconia particles in acetic acid) yields films of similar quality to those from conventional approaches (such as electrochemical vapor deposition), but at potentially much less expense. A key factor in obtaining high-density, adherent films via the EPD approach is the application of a thin fugitive phase (carbon in this study) on the porous, doped lanthanum manganite cathode tubes prior to zirconia deposition.
Coordination Environment and Vibrational Spectroscopy of Cr(VI) Sites Supported on Amorphous Silica

Chromium(VI) sites homogeneously dispersed in a transparent silica xerogel matrix have been investigated to determine the coordination environment and rationalize the Raman spectra. X-ray absorption fine structure (EXAFS) analysis gives a structure that is consistent with Cr containing two terminal oxygens and is bound to the silica by two Cr−O−Si linkages. The structure was refined to an R factor of 1.28%. The terminal CrO bonds were found to have a bond length of 1.60 A and bridging Cr−O bonds of 1.80 A. The Raman spectrum, collected with 785 nm excitation above the absorption edge of the chromium, shows a strong band at 986 cm-1 and a resolved shoulder at 1001 cm-1. Isotopic labeling and polarization studies of low concentrations of Cr (0.5 mol %) indicate that the strong 986 cm-1 band is the totally symmetric Cr(O)2 mode; however, the isotopic shift and strong polarization of the 1001 cm-1 mode preclude it from being the antisymmetric component of the terminal dioxo stretch. At higher concentrations (...
Compositionality and sandbag semantics

It is a common view that radical contextualism about linguistic meaning is incompatible with a compositional explanation of linguistic comprehension. Recently, some philosophers of language have proposed theories of ‘pragmatic’ compositionality challenging this assumption. This paper takes a close look at a prominent proposal of this kind due to Francois Recanati. The objective is to give a plausible formulation of the view. The major results are threefold. First, a basic distinction that contextualists make between mandatory and optional pragmatic processes needs to be revised. Second, the pragmatic theory can with stand a Davidsonian objection only by rejecting the importance of a distinction between primitive and non-primitive semantic items. Thirdly, however, the theory is now open to a worry about how it should be understood: either the theory consists in a very broad functionalist generalization about communication, which makes it explanatorily inert, or it boils down to a highly particularist view about linguistic meaning. Finally, I argue that Recanati’s notion of ‘occasion meaning’ is problematic and suggest replacing it with the notion of speaker meaning, which is explanatorily more basic.
Vortex reconnection in superfluid helium.

A useful physical model for superfluid turbulence considers the flow to consist of a dense tangle of vortex lines which evolve and interact. It has been suggested that these vortex lines can dynamically reconnect upon close approach. Here, we consider the nonlinear Schr\"odinger equation model of superfluid quantum mechanics, and use numerical simulation to study this topology changing core-scale process. Our results support the idea that vortex reconnection will occur whenever filaments come within a few core lengths of one another.
Papillary cystic neoplasm of the pancreas: a report of three pediatric cases and literature review.

Abstract Background/Purpose: Papillary cystic neoplasms are rare pancreatic tumors that typically present in women in their third decade of life. Few cases have been reported in children. Methods/Results: The authors report on three pediatri patients: a 10-year-old boy, an 11-year-old girl, and a 14-year-old girl. The authors have reviewed the existing literature on papillary cystic neoplasms of the pancreas and suggest that these tumors probably arise early in life, grow slowly, and metastasize infrequently. Conclusion: Even when these tumors metastasize, patients seldom die as a result of the malignancy.
Alcohol, wine, and health

Abstract Background: For the past 20 years numerous epidemiological studies have correlated the consumption of alcohol and a variety of disease states: overall mortality, arteriosclerotic vascular diseases, hypertension, cancers, peptic ulcer, respiratory infections, gall stones, kidney stones, age-related macular degeneration, bone density, and cognitive function. Methods: A review of these articles reveals that each of these studies has compared the outcome of individuals at various levels of alcohol consumption with that of abstainers. Results: Each analysis has identified a U-shaped or J-shaped curve of reduced relative risk for a given disease state compared with abstainers. A clear definition of consumption in moderation becomes evident: for men it should not exceed 2 to 4 drinks per day, and for women it should not exceed 1 to 2 drinks per day. Conclusions: Alcohol by itself has favorable effects on the level of high-density lipoprotein cholesterol, and inhibition of platelet aggregation. Wine, particularly red wine, has high levels of phenolic compounds that favorably influence multiple biochemical systems, such as increased high-density lipoprotein cholesterol, antioxidant activity, decreased platelet aggregation and endothelial adhesion, suppression of cancer cell growth, and promotion of nitric oxide production.
Lack of Demonstrable Autocrine Hedgehog Signaling in Human Prostate Cancer Cell Lines

Purpose: Several recent reports highlighted the role of hedgehog signaling in prostate cancer. However, the relative contributions of autocrine and paracrine hedgehog signaling to tumor growth and progression are unclear. Efforts to model autocrine signaling for drug development have been hampered by conflicting reports of the presence or absence of autocrine signaling in established human prostate cancer cell lines.Materials and Methods: We comprehensively characterized the expression of hedgehog pathway genes in the 3 prostate cancer cell lines LNCaP, PC3 and 22RV1 (American Type Culture Collection, Manassas, Virginia). We also examined their response to Shh ligand and to the hedgehog pathway inhibitor cyclopamine (Toronto Research Chemicals, Toronto, Ontario, Canada).Results: Expression of hedgehog ligand, patched and Gli1 in all 3 cell lines was lower than the expression level in normal human prostate tissue. All 3 cell lines showed hedgehog target gene activation when transfected with an activated fo...
Impact of Retrograde Cerebral Perfusion on Ascending Aortic and Arch Aneurysm Repair

Abstract Purpose . The effect of retrograde cerebral perfusion on the incidence of stroke and death among patients undergoing repair of aneurysms of the ascending aorta and transverse arch was determined. Material and Methods . Between January 1991 and March 1995, 161 patients were operated on for aneurysms of the ascending aorta and transverse arch. Thirty-three of the patients (20%) had an aneurysm of the ascending aorta only and 128 (80%) had aneurysms of both the ascending aorta and the transverse arch. All the patients underwent cardiopulmonary bypass, profound hypothermia, and circulatory arrest, and 120 (74%) also underwent retrograde cerebral perfusion. Median pump time was 143 minutes (range, 21 to 461 minutes). Median circulatory arrest time was 42 minutes (range, 8 to 111 minutes), and median myocardial ischemic time was 71 minutes (range, 14 to 306 minutes). Results . The overall 30-day mortality rate was 6% (9 patients) and the incidence of stroke was 4% (7 patients). The use of retrograde cerebral perfusion demonstrated a protective effect against stroke (3 of 120 patients, or 3%) compared with no retrograde cerebral perfusion (4 of 41 patients, or 9%; odds ratio, 0.24; confidence interval, 0.06 to 0.99; p p p p Conclusion . Retrograde cerebral perfusion decreased the incidence of stroke in patients undergoing repair of aneurysms of the ascending aorta and transverse arch. (Ann Thorac Surg 1997;63:1601–7)
Homeobox gene expression induces a pro-angiogenic state following hindlimb ischemia

Introduction: Homeobox genes are a large family of transcriptional mediators that are essential in the process of angiogenesis. The role of Hox gene expression after hindlimb ischemia is not known. The purpose of this study is to characterize the expression of pro-angiogenic (HoxD3) and anti-angiogenic (HoxD10) genes in a murine model of hindlimb ischemia. Methods: Femoral artery resection was performed in the left hindlimb of C57Bl/6 mice, with the right limb serving as control (n = 20). Hindlimb perfusion was determined using laser Doppler technique. Animals were sacrificed at 4, 7, 14, 28 days after surgery. Gastrocnemius samples were harvested for RNA isolation. RT-PCR was performed for HoxD3, HoxD10, B3-integrin and Col1A1. In situ hybridization was performed on histological sections of calf muscle to determine tissue expression of HoxD3. Results: Hindlimb ischemia was maximal at 4d (L/R ratio = 0.3), with recovery by 28d (L/R ratio = 0.8). No limb loss was observed. HoxD3 expression was significantly increased at 4d and 7d after the induction of ischemia, with decreased expression at 14d and 28d. Downstream genes, B3-integrin and Col1A1, show a similar timecourse of increased expression. HoxD10 shows a reciprocal decrease in expression after hindlimb ischemia. In situ hybridization confirmed the tissue expression of HoxD3, primarily localized to areas of new blood vessel formation. Table 1. PCR relative expression (left/right ratio) 4 days 7 days 14 days 28 days HoxD3 1.55∗ 1.76∗ 1.01 1.02 B3-integrin 2.24∗ 2.56∗ 1.01 1.07 Col1A1 2.00∗ 1.89∗ 0.98 1.01 HoxD10 0.35∗ 0.61∗ 0.84 0.86 ∗ p < 0.05 using student’s t-test (n = 4 per group). Conclusions: These findings support the hypothesis that Hox gene expression is important in the creation of a pro-angiogenic state following hindlimb ischemia.
Ecology of understory kelp environments. II, Effects of kelps on recruitment of benthic invertebrates

Abstract Previous studies demonstrated that understory kelps altered rates of mass and particulate transport beneath kelp canopies. This study examined the implications of these physical effects, plus shading by canopies, on the recruitment of four taxa of benthic invertebrates. Using field manipulations of understory kelp density and substratum orientation, we examined the effect of kelps on invertebrate recruitment and assessed the mechanisms involved. These mechanisms included reduced flow, increased sedimentation, reduced light intensity and reduced microalgal cover. All effects were significant to recruitment, but their relative importance varied among taxa. Two species examined, the serpulid polychaete Pseudochitinopoma occidental (Bush) and the cheilostome bryozoan Membranipora membranacea (Linnaeus) have long-lived planktonic larvae. Kelp canopies significantly affected recruitment of these two species, but in different ways. Pseudochitinopoma recruitment was reduced by sedimentation and light but was unaffected by ambient flow directly. Recruitment of Membranipora exhibited patterns consistent with that of passive transport of larvae with higher recruitment in high flow, no-kelp environments. Its recruitment was reduced by higher sedimentation beneath canopies, but showed no response to changes in light intensity. Spirorbid polychaetes have short planktonic phases of unknown durations. Kelps significantly affected their recruitment but difference in recruitment rates between kelp-covered and exposed substrata varied in direction with season. Spirorbid recruitment was reduced by light and high levels of sedimentation, but their recruitment patterns were unaffected by ambient flow directly. The cyclostome bryozoan Tubulipora sp. has a very short planktonic period (seconds to minutes) and factors affecting its recruitment were consequently difficult to decipher. It apparently responded negatively to higher light intensity and increased sedimentation. The effects of kelp canopies on recruitment depend on the complex interaction of these variables.
Enhanced Gene and siRNA Delivery by Polycation-Modified Mesoporous Silica Nanoparticles Loaded with Chloroquine

Purpose To prepare mesoporous silica-based delivery systems capable of simultaneous delivery of drugs and nucleic acids.
China’s Economic Reforms in a Comparative Perspective

The paper makes recommendations for simultaneously establishing macroeconomic equilibrium and extending the reform effort in China. As to the latter, recommendations are made (a) for increasing the decision-making power of enterprises which are to respond to profit incentives; (b) establishing the conditions for competition; (c) reforming prices; and (d) linking bonuses to work performance. The paper notes the desirability of taking simultaneous action in all these respects.
Engineering Biological Systems with Synthetic RNA Molecules

RNA molecules play diverse functional roles in natural biological systems. There has been growing interest in designing synthetic RNA counterparts for programming biological function. The design of synthetic RNA molecules that exhibit diverse activities, including sensing, regulatory, information processing, and scaffolding activities, has highlighted the advantages of RNA as a programmable design substrate. Recent advances in implementing these engineered RNA molecules as key control elements in synthetic genetic networks are highlighting the functional relevance of this class of synthetic elements in programming cellular behaviors.
Second harmonic generation and crystalline structure of corona poled BaTiO3 thin films

Abstract Second harmonic generation from a 1.064 μm fundamental was measured on BaTiO 3 thin films derived from metalorganic chemical vapor deposition. Significant enhancement of the second harmonic generation was observed upon poling of the film using corona discharge. The second harmonic intensity of the poled film was studied as a function of the incident fundamental polarization, showing that there was no in-plane symmetry in the poled films. The measured macroscopic second-order nonlinear optical coefficient of the poled film, d film 33 , is ∼ 7.5 pm/V. This value is comparable to that of the bulk BaTiO 3 along c -axis, d BaTiO 3 33 , suggesting that the majority of the crystalline c -axis of the poled film was aligned to the film normal.
Phase-Field Crystal Model for Fe Connected to MEAM Molecular Dynamics Simulations

A recently developed phase-field crystal (PFC) model incorporates elasticity and plasticity in the microstructural evolution of materials naturally by representing the density field for the crystalline state by periodic functions and by using a constant density for liquid state. PFC is of great interest in nano- and micro-structural modeling of materials because it is a model with atomistic scale details but is applicable to diffusive time scales. However, determining model parameters for specific materials is one of the less developed aspects of PFC modeling. In this article, molecular dynamics (MD) simulations of solid–liquid structures for Fe were performed using the modified embedded-atom method to determine the melting point, latent heat, expansion in melting, density profile, and liquid structure factor. The influence of simulation cell size on the results of MD simulations was also investigated. The melting temperature, density profile, and liquid structure factor were used as inputs to find model parameters required by the PFC model for Fe. The spatial derivative order of the PFC time-evolution equation was reduced from four to two, and the resultant system of partial differential equations was solved numerically using the finite element method. The required simulation domain and element size for the convergence of the PFC simulations were determined, and the expansion in melting, latent heat and solid–liquid surface free energy were calculated. The PFC results were compared with the results of other computational and experimental works in the literature.
Immobilized and solid-state reagent systems for luminol chemiluminescence in flow systems

To facilitate the application of luminol chemiluminescence in analysis, several approaches are investigated to provide the reagents in immobilized or solid-state format. The approaches are demonstrated with flow injection systems. Luminol is covalently bound or adsorbed to the surface of small support particles and packed into flow-through reactor/detector cells. The catalyst can be either covalently immobilized heme-containing species or a positively-biased electrode in an electrochemical cell. Peroxide can be obtained electrochemically at a negatively-biased electrode. These immobilized reagent systems can be combined to yield single-channel flow systems for determination of hydrogen peroxide (0.15μM detection limit) or luminol (0.1 nM detection limit).
Dynamics of the urban zoning structure: An empirical investigation of zoning change

Abstract This study empirically examines the role of land prices in the decision to rezone vacant land from one land use to another. Although the study of zoning and related issues is well documented, this is one of only a handful of studies that directly examines zoning changes. Unlike previous studies that treat zoning as static, acknowledging only that the current allocation of land differs from the market allocation, this study examines if the allocation of land will be reallocated (rezoned) toward a market allocation. The study is unique in that it analyzes zoning changes on an individual property basis and is based on transactions of vacant parcels. The data are drawn from a single municipality, Chicago—Illinois, allowing a uniform definition of zoning classification rather than trying to combine data under multiple zoning authorities.
Quantum effects on hydrogen adsorption in internal nanospaces of single-wall carbon nanohorns

Hydrogen adsorption isotherms in single-wall carbon nanohorns (SWNHs) have been measured at 20 K. The pore volume from hydrogen adsorption is compared with that from nitrogen adsorption at 77 K to determine the density of confined hydrogen in the internal space of SWNHs; it indicates that the average density of confined hydrogen inside SWNHs at 20 K is higher than that of liquid hydrogen in the bulk and nearly approaches the density of solid hydrogen at the triple point. The surface area from hydrogen adsorption using the BET theory is anomalously large compared with that for nitrogen; however, an alternative method (modified BET theory), in which an assumption is made that the energy of a molecule in the second layer is larger than that in the liquid, gives a reasonable surface area, especially when the adsorbed hydrogen in the first layer is assumed to be in a solid state. In the modified BET model, a packing constraint of the second layer due to the cylindrical geometry of SWNH is also taken into accou...
Risk factors for very preterm delivery and delivery of very-small-for-gestational-age infants among HIV-exposed and HIV-unexposed infants in Botswana.

Abstract Objective To evaluate risk factors for very preterm delivery (VPTD) and very-small-for-gestational-age (VSGA) births in a country with a high HIV prevalence. Methods Obstetric records at 6 hospitals across Botswana were reviewed at delivery; VPTD was defined as birth before 32 weeks of pregnancy and VSGA as birth weight below the 3rd percentile for Botswana-specific norms. Results Of 16 219 live births born after 26 weeks of pregnancy, 701 (4.3%) were delivered very preterm and 607 (3.7%) were VSGA; 4347 (28.4%) were documented as HIV-exposed. In a multivariable analysis, HIV infection and hypertension during pregnancy were associated with a VPTD (adjusted odds ratio [AOR]: HIV 1.65, hypertension 1.75) and a VSGA birth (AOR: HIV infection 1.90, hypertension 3.44). Among HIV-infected women, the continuation of highly active antiretroviral therapy (HAART) from before conception was associated with a VSGA birth (AOR 1.75) but not with a VPTD (AOR 0.78). In a secondary analysis, HAART continuation was associated with hypertension during pregnancy (AOR 1.34). Conclusion Hypertension and HIV infection were risk factors for a VPTD and a VSGA birth. Continuation of HAART from before conception was associated with a VSGA birth but not with a VPTD.
Self-assembly of rod–coil block copolymers

Abstract Rod–coil block copolymers are an increasingly important class of molecules for the self-assembly of functional polymer systems, many of which have rodlike chain conformations due to rigid secondary structures, extended π-conjugation, or aromatic groups along the polymer backbone. Examples of these polymers are helical proteins, polyisocyanates, main-chain semiconducting polymers, and aromatic polyesters, polyamides, or polyimines. Many hindered or liquid crystalline systems self-assembled from block copolymers, including dendronized polymers and mesogen-jacketed liquid crystalline polymers, also form rod–coil block copolymers. In these cases, steric crowding of the bulky or mesogenic side chains causes the polymer backbone to become quasi-linear. The incorporation of rigid rod polymers into the block copolymers results in extremely rich self-assembly behavior that differs markedly from that of traditional block copolymers due to the interplay between microphase separation of the rod and coil components and liquid crystalline alignment. The combination of these effects results in novel structures both in solution and melts. This review discusses in detail the self-assembly and thermodynamics of rod–coil diblock and triblock copolymers. After summarizing the applications of these materials, their aggregation and gelation in solution is discussed. Our knowledge of their bulk phase behavior is thoroughly reviewed both from the experimental and theoretical perspectives, and the self-assembly of these materials in thin film geometries that are critical to many applications in organic electronics and functional surface patterning is treated. Finally, the outlook for the future of these systems is summarized along with current knowledge gaps and exciting areas for the advancement of the field.
Runoff and sediment yield relationships with soil aggregate stability for a state-and-transition model in southeastern Arizona

Abstract Soil erosion has been identified as the primary abiotic driver of site degradation on many semiarid rangelands. A key indicator of erosion potential that is being increasingly implemented in rangeland evaluations is soil aggregate stability (AS) as measured by a field soil slake test. However, there have been few studies that test if decreasing AS is an indication of increasing soil erosion. A rainfall simulator experiment was conducted in southeastern Arizona to measure runoff and erosion, aggregate stability, and cover attributes on three vegetation states of the state-and-transition model (STM) of the Loamy Upland ecological site (R041XC313AZ). The states included the reference state (RS), a site encroached by mesquite (MN), and a site invaded by Eragrostis lehmanniana (ML). Within the context of the STM, runoff was only different between very high and low cover states. Erosion and AS values differentiated among states, particularly between the RS and MN states. Relationships between runoff and erosion with canopy cover and interspace bare soil suggest that certain cover levels exist where runoff and erosion have the potential to increase. The results also indicated that for this ecological site, AS
The multiphoton dissociation spectrum of bis(perfluoroisopropyl) ketone

Abstract Multiphoton absorption and dissociation of bis(perfluoroisopropyl) ketone induced by a transversely excited atmospheric pressure CO 2 laser was studied as a function of the wavelength λ and the fluence F of the IR field. The molecule is almost uniquely suited to this type of study: its chemistry is simple allowing unambiguous actinometry and its adsorption spectrum is located at the centre of the 10P branch of the 13 CO 2 laser allowing the investigation of the full action spectrum. Both the probability P d (λ, F ) of dissociation and the average number 〈 n 〉(λ, F ) of photons absorbed per molecule were measured at constant pressure (0.5 Torr). The spectral dependence of P d at constant fluence is a single lorentzian function of halfwidth 5.8 cm −1 red shifted 6.0 cm −1 from the small signal IR absorption band. The peak for 〈 n 〉 is broader (full width at half-maximum of about 14 cm −1 ), asymmetric and red shifted by only 2.2 cm −1 .
Defective secretory-protein mRNAs take the RAPP

Secretory proteins destined for the lumen of the endoplasmic reticulum are key regulators of cellular functions and are thus subject to several levels of quality control. A recent study finds that the earliest step in secretory protein biogenesis – binding of the signal recognition particle to the signal sequence of the nascent peptide – is subject to a quality control process termed RAPP for ‘regulation of aberrant protein production’. This process involves AGO2 and mRNA degradation.
Bone-derived CAD library for assembly of scaffolds in computer-aided tissue engineering

To aid in the development of scaffolds for tissue engineering, we propose a library of architectures (unit primitives) that may be strategically merged according to various characteristics. In particular, for bone, mechanical characteristics such as the regional stiffness, micro-architectural levels of mechanical surface strain, void fraction amount and orientation, as well as permeability and other parameters will be critical both individually and in concert. As relationships between the aforementioned parameters are elucidated, the potential to successfully engineer scaffolds improves. Here we expound upon previous research of creating assembled scaffolds from derived analytical shapes, extending it to encompass native human trabecular bone architecture, derived from repeated patterns witnessed in the interior portion of human vertebrae. Several results are reported; namely, the description of numerous tissue primitives and interfaces with commentary on their morphological characteristics, the integrati...
Cumulative effects of wild ungulate and livestock herbivory on riparian willows

We examined the effects of wild ungulates (deer and elk) and domestic sheep browsing on the growth, structure, and reproductive effort of two common willow species, Salix boothii and S. geyeriana, in a montane northeast Oregon riparian zone. With the use of exclosures, large herbivore effects on willows were studied in an area browsed by native mammals only and an adjacent area in which domestic sheep also lightly grazed during summer months. Growth variables were repeatedly measured on individual plants over a 5-year period to understand physiognomic and flowering responses of native willows to different levels of browsing pressure. At the beginning of the study, all willows were intensely browsed but were significantly taller in the area browsed only by native mammals than in the area also grazed by sheep (69 versus 51 cm, respectively). Willows inside exclosures responded with pronounced increases in height, crown area, and basal stem diameters while the stature of browsed plants outside exclosures stayed constant or declined. In the area browsed by both sheep and wild herbivores, the size of browsed plants remained at pre-treatment levels (<60 cm in height) for the duration of the study. There was no significant difference in growth rates of enclosed willows, indicating that current herbivory was the primary cause of growth retardation in the study area. Foliar area was strongly correlated with basal stem numbers for enclosed plants but much less so for browsed plants. Willows inside exclosures had more than twice as much foliar area per stem. Stem diameters were a positive function of crown area: stem-number ratios, suggesting lower photosynthetic potential was correlated with diminished radial growth among browsed plants. No flowering was observed until 2 years after exclusion when plants inside all exclosures and browsed willows in the wild ungulate area responded with a large pulse in flowering. Browsed plants in the sheep + wild ungulate area did not flower. The number of catkins produced per plant was significantly associated with willow height and plants <70 cm in height did not flower, thus suggesting a size threshold for reproduction in these species. Our results suggest that even relatively light levels of domestic livestock grazing, when coupled with intense wild ungulate browsing, can strongly affect plant structure and limit reproduction of riparian willows.
Scaling behavior for dynamic permeability in porous media

Abstract We present theoretical and experimental evidences that show the frequency-dependent permeability κ(ω) for a porous medium is a scaling function with only two parameters; i.e. κ ( ω )/ κ 0 = κ ~( ω / ω c ), where κ 0 is the static permeability, ω c is a characteristic frequency particular to the sample, and κ~ is a function dominated by the geometry of the throat regions in a medium. If the pore cross sectional area varies slowly near the throat, the κ~ is an approximate universal function independent of porous microstructures. We advance arguments that delineate the physical origin for the scaling behavior as well as the condition for its validity.
Correlations in binary liquid and glassy metals

Abstract It is shown, starting from a nearly-free electron approximation, how correlations can occur in the atomic positions of binary liquid and glassy alloys. In particular, it follows from energy considerations that for an alloy of a transition metal with a metalloid there is a concentration region where there should be no metalloid-metalloid nearest neighbors. This concentration region is just the same as that where glass formation is often observed in these systems.
Hard switching speed improvements in GaN-based synchronous buck converters

In designing high efficiency, large step down buck converters, the power semiconductors contribute a significant loss mechanism through switching losses. Minimizing these losses can be achieved by running at lower frequencies, decreasing the actual switching time, or performing soft switching. However, soft switching converters introduce extra components, which can impact reliability, cost, and size of the final converters. Therefore, extremely rapid hard switching is preferable to soft switching converters. This paper proposes a new layout technique for low parasitic inductance paths using commercially standard PCB specifications for very fast switching speeds of GaN power devices in flip-chip packages resulting in a highly efficient (>94%) hard switching 12-1 V synchronous buck converter. The proposed technique is experimentally verified at output loads from 4 - 20 A and achieves less than 5 ns switching times.
Exploring Themes of Resiliency in Children after the Death of a Parent

The purpose of the phenomenological and grounded qualitative study in this article was to explore resilient traits of children, aged 9 to 12, who experienced the death of a parent within the past 36 months. The researcher assisted the children in narrating and writing their stories about parental loss and adaptation by posing questions guided by a review of literature framed in an ecological context. Data were coded and analyzed, uncovering themes of resilience. Implications for school counselors working with students who have parental grief experiences are discussed.
“Nadie Me Dijó [Nobody Told Me]” Language Policy Negotiation and Implications for Teacher Education

Nationwide and statewide shifts and ambiguity in language education policy have created substantial instability for teachers. Through a cross-case study and analysis of bilingual teachers in two states, this article shows how these teachers participate in responding to and making decisions regarding language policy. This article shows how and why an understanding of language policy and the decision making involved with it is a crucial dimension of the professional roles of teachers who have second-language learners in their classrooms. Thus, the authors broaden the discussion on the teacher preparation for the instruction of English-language-learner students, which has narrowly focused on an awareness of language and methods, to include the dimension of policy making.
Nonsteroidal antiinflammatory drugs and acute myocardial infarction in patients with no major risk factors.

Study Objective. To assess the risk of long-term use of five nonsteroidal antiinflammatory drugs (NSAIDs)—rofecoxib, celecoxib, ibuprofen, naproxen, and diclofenac—in relation to acute myocardial infarction. Design. Five separate nested case-control studies, one for each NSAID, designed to minimize important biases present in other observational studies. Setting. University-affiliated research program. Data Source. The United Kingdom General Practice Research Database (GPRD). Measurements and Main Results. We identified all people in the GPRD aged 30–79 years who had a first recorded prescription for rofecoxib, celecoxib, ibuprofen, naproxen, or diclofenac after January 1, 1999. Cases of newly diagnosed, first-time acute myocardial infarction were then identified from the study population, along with matched control subjects. Relative risk estimates for acute myocardial infarction in patients with no recorded major clinical risk factors for acute myocardial infarction were determined for each NSAID according to receipt of 2–4, 5–9, 10–19, or 20 or more prescriptions compared with receipt of only 1 prescription. Results were adjusted for relevant variables possibly related to the risk for acute myocardial infarction. No material elevation of risk according to the number of prescriptions received for ibuprofen or naproxen was noted. However, a substantial increased risk similar to that found in clinical trials was noted in patients who received 10 or more prescriptions for rofecoxib, celecoxib, or diclofenac. Conclusion. Extensive use of rofecoxib, celecoxib, and diclofenac increases the risk of acute myocardial infarction, but similar use of ibuprofen and naproxen does not.
Nucleic acids as growth rate indicators for early developmental stages of Calanus pacificus Brodsky

Abstract Relationships among RNA and DNA contents, dry weight, and growth rate were investigated for the copepod Calanus pacificus Brodsky cultured under different temperature and food conditions. For a given culture condition, RNA/mg dry wt, RNA/DNA, and RNA/ animal tended to be positively, although weakly, correlated with growth rate. Copepods cultured at low temperature (8 °C), however, had higher RNA contents than faster growing animals from higher temperature (15 °C). Moreover, animals from low-temperature, high-food and high-temperature, low-food cultures had similar growth rates but markedly different levels of RNA. We conclude that the underlying relationships among nucleic acid contents and ratios, food, temperature, organism size, and developmental stage are too complex and contradictory for nucleic acids to be useful indicators or predictors of Zooplankton growth rates under field conditions.
Characterization of a defective phage system for the analysis of bacteriophage T4 DNA replication origins.

Abstract We have developed a defective phage system for the isolation and analysis of phage T4 replication origins based on the T4-mediated transduction of plasmid pBR322. During the initial infection of a plasmid-containing cell, recombinant plasmids with T4 DNA inserts are converted into fully modified linear DNA concatamers that are packaged into T4 phage particles, to create defective phage (transducing particles). In order to select T4 replication origins from genomic libraries of T4 sequences cloned into the plasmid pBR322, we searched for recombinant plasmids that transduce with an unusually high efficiency, reasoning that this should select for T4 sequences that function as origins on plasmid DNA after phage infection. We also selected for defective phage that can propagate efficiently with the aid of a coinfecting helper phage during subsequent rounds of phage infection. which should select for T4 sequences that can function as origins on the linear DNA present in the defective phage. Several T4 inserts were isolated repeatedly in one or both of these selective procedures, and these were mapped to particular locations on the T4 genome. When plasmids were selected in this way from genomic libraries constructed using different restriction nucleases, they contained overlapping segments of the T4 genome, indicating that the same T4 sequences were selected. The inserts in two of the selected plasmids permit a very high frequency of transduction from circular plasmids: these have been shown to contain a special type of T4 replication origin.
Strain Tensors at the Atomic Scale

Almansi and Green strain tensors are developed for use in large deformation molecular dynamics/statics simulations that employ Embedded Atom Method (EAM) potentials for metals. The strain tensors are formulated with respect to the deformation gradient. A scalar potential function is used with a weighting function that is dependent upon a cutoff radius for the deformation gradient. For a homogeneous or inhomogeneous deformation, a cutoff distance of one lattice parameter can be used to approximate local strain level. Inhomogeneous deformation reveals different results for Almansi and Green strain tensors indicating that the small strain assumption cannot be used to determine large atomic strains.
Seasonal Variations in Vertical Redox Stratification and Potential Influence on Trace Metal Speciation in Minerotrophic Peat Sediments

Seasonal variations in pore water and solid phase geochemistry were investigated in urbanized minerotrophic peat sediments located in southwestern Michigan, USA. Sediment pore waters were collected anaerobically, using pore water equilibrators with dialysis membranes (“peepers”) and analyzed for pH, alkalinity, dissolved ΣPO4 −3, ΣNH4 +, ΣS−2, SO4 −2, Fe+3, Fe+2, and Mn+2 at 1-2 cm intervals to a depth of 50 cm. Cores collected adjacent to the peepers during all four seasons were analyzed for reactive solid phase Fe according to extraction methods proposed by Kostka and Luther (1994). The association of Fe and trace metals (Mn, Pb, Zn, Cu, Cr, Co, Cd, U) with operationally defined solid phase fractions (carbonates, iron and manganese oxides, sulfides/organics and residual) was assessed for cores extracted during winter and spring using extraction methods proposed by Tessier et al. (1979, 1982). Pore water Fe and S data demonstrate a clear seasonal variation in redox stratification of these sediments. The redox stratification becomes more compressed in spring and summer, with relatively more reducing conditions closer to the sediment water interface (SWI), and less reducing conditions near the SWI in fall and winter. In the upper 10–15 cm of sediment, the pool of ascorbate extractable Fe, thought to be indicative of reactive Fe(III) oxides, diminishes during spring and summer, in agreement with seasonal changes in redox stratification indicated by the pore water data. Tessier extractions indicate that the total extractable quantity of all metals analyzed in this study decrease with depth, and that the majority of the non-residual Fe, Pb, Zn, Cu, Cr, Co, Cd, and U is typically associated with the sulfide/organic fraction of the sediments at all depths. Non-residual Mn, in contrast, is significantly associated with carbonates in the upper 15–25 cm of the sediment, and predominantly associated with the sulfide/organic fraction only in deeper sediments.