cssi/SciSciGPT-SciSciNet huggingface dataset:
Hydrogen Bonding, Solvent Exchange, and Coupled Proton and Electron Transfer in the Oxidation and Reduction of Redox-Active Tyrosine YZ in Mn-Depleted Core Complexes of Photosystem II

The redox-active tyrosines, YZ and YD, of Photosystem II are oxidized by P680+ to the neutral tyrosyl radical. This oxidation thus involves the transfer of the phenolic proton as well as an electron. It has recently been proposed that tyrosine YZ might replace the lost proton by abstraction of a hydrogen atom or a proton from a water molecule bound to the manganese cluster, thereby increasing the driving force for water oxidation. To compare and contrast with the intact system, we examine here, in a simplified Mn-depleted PSII core complex, isolated from a site-directed mutant of Synechocystis PCC 6803 lacking YD, the role of proton transfer in the oxidation and reduction of YZ. We show how the oxidation and reduction rates for YZ, the deuterium isotope effect on these rates, and the YZ• − YZ difference spectra all depend on pH (from 5.5 to 9.5). This simplified system allows examination of electron-transfer processes over a broader range of pH than is possible with the intact system and with more tractab...
Meniscectomies in children Report of long-term results (mean, 8.3 years) of 26 children

Controversy exists over the management of the pediatric patient with a suspected tear of the meniscus. Twenty-six patients who underwent uncomplicated meniscectomy during a period of open epiphyseal plates were reviewed by personal followup. The average followup of these 26 patients was 8.3 years. Ligamentous laxity, early degenerative arthritis, and symptomatic knee pain were found; only 42% demonstrated an excellent or good result. Intensive preoperative evaluation and conservative management of selected meniscal lesions in children are recommended.
Interaction of hydrogen sulfide with Zr0.92Y0.08O2−δ/40% Ni cermet

Abstract The interaction of hydrogen sulfide with a cermet composed of zirconium oxide and yttrium oxide doped with metallic nickel (Ni) in the stoichiometric form Zr 0.92 Y 0.08 O 2− δ /40 vol% Ni and a pure nickel metal was studied at 500 and 650 °C utilizing high temperature X-ray photoelectron spectroscopy and high-temperature scanning electron microscopy. The hydrogen sulfide (H 2 S) did not appear to interact with the cermet at 500 °C with H 2 S exposures of 6 × 10 −5 Torr for 1 h, but interaction of H 2 S with the cermet was observed at 650 °C at similar H 2 S exposures. The amount and the rate of reaction of H 2 S were significantly lower with the cermet than with the pure nickel metal at 650 °C with similar H 2 S exposures. The dispersion of nickel in the zirconium and yttrium oxide matrix decreased the reaction of H 2 S with nickel in the cermet.
Extending matchings in claw-free graphs

Abstract Let G be a graph with a perfect matching and let n be an integer, 1⩽ n V ( G )|⧸2. Graph G is n - extendable if every matching of size n in G is a subset of a perfect matching. Graph G is bicritical if G — u — v has a perfect matching for every pair of points u and v in V ( G ). It is proved that every 3-connected claw-free graph is bicritical and for n ⩾2, every (2 n +1)-connected claw-free graph is n -extendable. Matching extension in planar and toroidal claw-free graphs is then considered.
Homogenization techniques for thermoviscoelastic solids containing cracks

Abstract In this paper mathematical techniques are developed for obtaining locally averaged (homogenized) constitutive equations for heterogeneous linear thermoviscoelastic solids. Homogenization principles will be developed for the cases wherein no internal boundaries are present, and also where internal boundaries in the form of sharp cracks are present, thus resulting in damage dependent macroscopic constitutive equations. The microthermomechanics problem will first be formulated, followed by the construction of the locally averaged equations resulting from the homogenization process. It will be shown that homogenized conservation laws and constitutive equations take the same form as do the local equations when locally linear thermoviscoelastic media are considered. However, the resulting homogenized constitutive equations will be nonlinear in the case wherein time dependent damage occurs. In addition, for materials of convolution type at the local scale, the homogenized equations will be shown to contain a term that depends on the time derivative of the strain localization tensor. Example problems will be discussed and the homogenized results will be given for these examples in order to demonstrate the technique.
Simulation of Mixed-mode I/III Stable Tearing Crack Growth Events Using the Cohesive Zone Model Approach

A cohesive zone model (CZM) approach is applied to simulate mixed-mode I/III stable tearing crack growth events in specimens made of 6061-T6 aluminum alloy and GM 6208 steel. The materials are treated as elastic–plastic following the \(J_{2}\) flow theory of plasticity, and the triangular cohesive law is employed to describe the traction-separation relation in the cohesive zone ahead of crack front. A hybrid numerical/experimental approach is employed in simulations using 3D finite element method. For each material, CZM parameter values are chosen by matching simulation prediction with experimental measurement (Yan et al. in Int J Fract 144:297–321, 2009), of the crack extension-time curve for the \(30^{\circ }\) mixed-mode I/III stable tearing crack growth test. With the same sets of CZM parameter values, simulations are performed for the \(60^{\circ }\) loading cases. Good agreements are reached between simulation predictions of the crack extension-time curve and experimental results. The variations of CTOD with crack extension are calculated from CZM simulations under both \(30^{\circ }\) and \(60^{\circ }\) mixed-mode I/III conditions for the aluminum alloy and steel respectively. The predictions agree well with experimental measurements (Yan et al. in Int J Fract 144:297–321, 2009). The findings of the current study demonstrate the applicability of the CZM approach in mixed-mode I/III stable tearing simulations and reaffirm the connection between CTOD and CZM based simulation approaches shown previously for mixed-mode I/II crack growth events.
Influence of pyridoxal phosphate on the binding of GABA to its transporter

Abstract Pyridoxal phosphate inhibited both the sodium-dependent binding of ( 3 H) GABA to its synaptic membranes and the uptake of ( 3 H) GABA into synaptosomes from the cat cerebral cortex. Further analysis of the inhibition of binding revealed this to be competitive in nature. If the membranes were preincubated with pyridoxal phosphate and treated with sodium borohydride, and then thoroughly washed, subsequent ( 3 H) GABA binding was reduced. This inhibition was both concentration and time dependent. The presence of GABA during the preincubation with pyridoxal phosphate protected against the inhibition. Thus it is apparent that the reversible and irreversible inhibition of GABA binding to its transporter is the result of an interference with the GABA binding process prior to uptake. Pyridoxal phosphate is known to inactivate certain enzymes by reacting with essential lysine residues, therefore the present results indicate that a lysine residue is at the GABA binding site of the carrier molecule and that this residue is essential for the binding of GABA.
Blockbusters and controlled substances: Miltown, Quaalude, and consumer demand for drugs in postwar America.

Abstract In 1955 Carter Products launched its new tranquilizer Miltown with a huge marketing blitz; Miltown soon became one of America’s earliest “blockbuster” celebrity drugs. In 1981, federal agents shut down a network of “stress clinics” and arrested the owners, medical staff, and other personnel for illegally trafficking in the sedative Quaalude; Quaalude soon became a “Schedule I Controlled Substance.” Both of these stories are familiar, indeed archetypal, moments from America’s postwar medical system. As the Miltown example reminds us, this fundamentally commercial system was built on the creation and courting of consumer demand for medical products and services, particularly drugs. As the Quaalude example shows, however, this system also incorporated tools for reining in excessive consumer demand. Together the two episodes affirm an enduring irony of the American medical system: the need for regulatory campaigns to tame lively markets for drugs that had become popular, in part, because of advertising campaigns. This article uses the Miltown and Quaalude sagas to explore the issue of consumer demand for prescription medicines, arguing that efforts to stoke or quash that demand have shaped (and linked) America’s medical system and its drug control regimes.
The Frequency of High-Impact Convective Weather Events in the Twin Cities Metropolitan Area, Minnesota

Abstract Thunderstorms frequently produce brief flooding or minor damage, though far fewer lead to major flooding and widespread or significant damage. Outbreaks of such storms exact large tolls on their victims and can compromise, or completely overwhelm, the emergency response infrastructure. This paper derives empirical frequencies and recurrence intervals of “high end” convective weather events in the Minneapolis–St. Paul, Minnesota, metropolitan area from archived tornado, hail, damaging-wind, and high-density daily rainfall data, as well as historical records and accounts. Two classes of high-impact events are analyzed: those with the potential to produce widespread damage or disruption and those virtually certain to do so. Storms in this first class recur within the area, on average, 3 times per year, while the more extreme storms recur every 2–2.5 yr on average. Owing to well-established spatial and temporal inhomogeneities in observed severe weather data, true recurrence intervals are probably so...
Phosphatidyl-2′,3′-dideoxy-3′-thiacytidine: synthesis and antiviral activity in hepatitis B- and HIV-1-infected cells

We recently found that phosphatidyl-2',3'-dideoxycytidine (phosphatidyl-ddC) had substantial anti-hepatitis B virus (HBV) activity in vitro compared to 2',3'-dideoxycytidine (ddC) (Hostetler et al. (1994) Antiviral Res. 24, 59-67). Upon administration of liposomal phosphatidyl-ddC to mice, a 40-fold higher drug area under curve was observed in the liver. To evaluate the possibility of using liver-targeted anti-HBV nucleosides to treat woodchuck hepatitis virus, we wanted to find the most potent and selective lipid conjugates. It has been shown that 2',3'-dideoxy-3'-thiacytidine as a racemic mixture of the cis-isomer (cis-(+/-)-BCH-189) has much greater activity against HBV viruses than ddC in vitro. Recently, it was shown that the (-)-beta-L-enantiomer (3TC) is more active and less toxic than the (+)-beta-D-form ((+)-BCH-189). To determine whether phospholipid conjugates of 3TC retain antiviral activity in 2.2.15 cells as demonstrated previously with ddC, we synthesized the 1,2-dipalmitoyl-sn-glycerol-3-phosphate conjugates of (+/-)-BCH-189 and 3TC and assessed their anti-HBV and anti-HIV activities, in vitro. Phosphatidyl-3TC and phosphatidyl-BCH-189 had antiviral activity comparable to the respective free drugs in 2.2.15 cells which chronically produce HBV. In HIV-1-infected human peripheral blood mononuclear cells and HT4-6C cells, phosphatidyl-3TC and phosphatidyl-(+/-)-BCH-189 exhibited significantly lower activity than the corresponding free nucleosides. In view of the documented ability of phosphatidyl-ddC to target drug to the liver, it seems reasonable to expect that phosphatidyl-3TC or phosphatidyl-(+/-)-BCH-189 could be employed to provide greatly enhanced hepatic antiviral activity in HBV infection in vivo.
Why are there so many loop formulas

A theorem by Lin and Zhao shows how to turn any nondisjunctive logic program, understood in accordance with the answer set semantics, into an equivalent set of propositional formulas. The set of formulas generated by this process can be significantly larger than the original program. In this article we show (assuming P n NC1 s poly, a conjecture from the theory of computational complexity that is widely believed to be true) that this is inevitable: any equivalent translation from logic programs to propositional formulas involves a significant increase in size.
DEVELOPMENTAL LOCALIZATION OF 2.1 PROTEIN IN MOUSE FETAL LUNG SUGGESTS A ROLE IN DETERMINATION OF CELL FATE

Hox genes are regulatory genes in mice containing a highly conserved homeobox region which are thought to control embryonic and fetal development. We have previously reported that hox 2.1 mRNA levels in fetal mouse lung are maximum on day 16, decreasing thereafter. Here we report the developmental localization of hox 2.1 protein in mouse fetal lung. Mice (fetal days 14 to 18; adult) were sacrificed and lungs frozen in liquid N2, cryosectioned and incubated with hox 2.1 polyclonal antibody (courtesy of N. Wall at Vanderbilt U.) followed by alkaline phosphatase immunostaining. Staining increased with gestation, was rare in adult specimens and was not seen in the absence of primary antibody. Nuclear staining was localized to subepithelial mesenchyme on day 14 and to both subepithelial mesenchyme and adjacent epithelial cells on day 15. As gestation progressed, staining localized to terminal bronchiolar columnar epithelium, abruptly decreasing or disappearing at branch points with transition to flattened epithelium. In conclusion, the change in localizatin of hox 2.1 protein from subepithelial mesenchyme to regionally restricted epithelia suggests a role in tho determination of epithelial cell fate and differentiation. The discordance between changes in mRNA levels and protein immunostaining suggests that hox 2.1 is complexly regulated during lung development.
Passage-Dependency Data in the Selection of Reading Comprehension Test Items

The reading comprehension items for a revision of a widely used standardized reading test were administered to several hundred fourth and sixth-grade pupils in order to determine the passage dependency of each item. All of the field-tested reading comprehension items were divided into nine booklets, which contained one normal reading comprehension subtest and one subtest with questions about passages that had been deleted. An index of passage dependency was computed for each item, and the index was used to help the authors locate items that were weak. The index also indicated the effect of passage dependency on skill categories.
Fast gas chromatography-differential mobility spectrometry of explosives from TATP to Tetryl without gas atmosphere modifiers

Explosives in solution were determined as mixtures containing highly volatile improvised explosives such as peroxides and conventional military grade explosives such as PETN, RDX, and Tetryl using a high speed gas chromatograph with differential mobility detector in a single measurement. Instrument parameters were evaluated and adjusted to permit detection of nanogram amounts of explosives with this broad range of vapor pressures in times under 3 min for HMTD to TNT or under 16 min for HMTD to Tetryl. As in prior studies of response to explosives with mobility spectrometers, pre-separation of sample by gas chromatography improved response in the differential mobility detector; however, unlike prior configurations, the supporting gas atmosphere did not contain modifiers to adjust selectivity in mobility and selectivity was provided only by characteristic stability of product ions in negative and positive polarities. Field dependence of product ions in purified air was determined for each explosive and patterns were sufficiently distinct to suggest the addition of selectivity through the use of several differential mobility detectors operated in parallel or series with characteristic separation voltages.
Relationship of blood pressure to cardiovascular death: the effects of pulse pressure in the elderly.

Abstract PURPOSE: To investigate the relationship of systolic and diastolic blood pressure to fatal myocardial infarction, fatal stroke and other death related to cardiovascular diseases (CVD). METHODS: The study was based on a prospective longitudinal study conducted by the Veterans Administration at the Boston Outpatient Clinic. Participants are male volunteers from the greater Boston area. Main outcome measures are fatal myocardial infarction, fatal stroke and other deaths related to cardiovascular diseases. The method of pooled logistic regression was used for statistical analysis. RESULTS: For younger men (age 21–59), after adjusting for effects of other risk factors, when systolic and diastolic blood pressure were considered separately, SBP was predictive of cardiovascular death (SBP: RR = 1.23; 95% CI = 1.05, 1.45 per 10 mmHg of increase ), and DBP showed a nonsignificant positive trend in relation to cardiovascular death (DBP: RR = 1.27; 95% CI = 0.95, 1.69 per 10 mmHg of increase ). For older men (age 60–85), when SBP and DBP were considered separately, SBP (RR = 1.26; 95% CI = 1.02, 1.55 per 15 mmHg of increase ) was directly related, but DBP (RR = 1.05; 95% CI = 0.83, 1.32 per 8 mmHg of increase ) was not related to cardiovascular death. However, for the elderly group, when SBP and DBP were considered jointly in the regression model, then the regression coefficient of DBP (β = −0.018, p = 0.30) was of approximately the same absolute magnitude as that of SBP (β = 0.021, p = 0.02) but opposite in sign. For younger men, when SBP and DBP were considered jointly, SBP (β = 0.021, p = 0.049) but not DBP (β = −0.001, p = 0.953) was positively related to cardiovascular death. CONCLUSIONS: We found that, for the elderly, pulse pressure (SBP-DBP) may be a more accurate predictor of cardiovascular death than either SBP or DBP alone. The relative risk per 35 mmHg of increase of pulse pressure, which equals the approximate interval from the 10th to the 90th percentile in the elderly group, is 2.1 with 95% CI = 1.1, 3.8 . In younger subjects, SBP, but not DBP, is an independent predictor of fatal CVD.
Convex solutions of certain elliptic equations have constant rank hessians

In this note we first consider solutions u of (1.1) Au = f ( u , Au) > 0 in a region ~2 of Euclidean n space (R"). Here Vu and Au denote the gradient and Laplaeian of u. We assume that f has H61der continuous second partial derivatives on some open set containing the range of the function x ~ (u(x), Vu(x)), x E ~ . We also assume that f is strictly positive, with 0.2) 2 ( L y (., Vu) f ( . , 7u)f , , ( . , Vu) > 0, that is, 1If(., 7u) is convex in u. Let H denote the Hessian matrix of u. Our main result is
HYDROTHERMAL TRANSPORT AND DEPOSITION OF RHENIUM UNDER SUBCRITICAL CONDITIONS REVISITED

Data on the solubility of Re metal in subcritical hydrothermal solutions presented in Xiong and Wood (2001) have been reinterpreted assuming that the following reaction controlled dissolved Re concentrations: ReO2( s ) + 2H2O( l ) ↔ Re(OH)4( aq ). The formation of ReO2( s ) on the surface of Re metal at the conditions of the previous experiments was demonstrated conclusively in a new experiment using X-ray photoelectron spectroscopy (XPS). The temperature dependence (200°–25°C) of the equilibrium constant for the above reaction at − 4700 ± 760 infinite dilution can be expressed as \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathit{K}\ =\ \frac{{-}4700\ {\pm}\ 760}{\mathit{T}}\ +\ 6.2\ {\pm}\ 2.0(2{\sigma})\) \end{document}. These new equilibrium constants predict that metallic rhenium, ReO2( s ), and ReS2( s ) have much lower solubilities than those implied in Xiong and Wood (2001). Based upon the new equilibrium constants, the free energy of formation, the enthalpy of formation, and entropy at the reference state (298.15 K and 1 bar) for the neutral rhenium species, Re(OH)4( aq ) (also alternatively formulated as ReO(OH)2( aq )), are derived in this study. Based on derived equilibrium constants at 25°C for dissolution of ReS2( s ) as Re(OH)4( aq ), we predict that rhenium can be enriched in the reduced zone in supergene environments in porphyry copper-molybdenum deposits.
Early Increased MT1-MMP Expression and Late MMP-2 and MMP-9 Activity during Angiotensin II Induced Aneurysm Formation

Background Angiotensin II (Ang II) is associated with a variety of cardiovascular diseases including aneurysm formation. The aim of this study was to evaluate the temporal changes in MT1-matrix metalloproteinase (MMP) and MMP-2 and -9 expression and activity during the course of Ang II induced experimental aneurysm formation. Methods Apolipoprotein E knockout mice (ApoE null) were infused with either 1000 ng/kg/min of Ang II (n = 20) or saline (n = 20) and then sacrificed at 7, 14, 21, and 28 days of infusion (n = 5/group/strain). Aortic diameters were measured by digital microscopy. Systolic blood pressure (SBP) was measured in the rodent tail. Suprarenal abdominal aortas had MT1-MMP mRNA levels and MMP-2 and MMP-9 mRNA levels and activity quantitated using reverse transcriptase–polymerase chain reaction (rt-PCR) and gelatin zymography, respectively. Statistical analyses included nonpaired t-test, Fisher’s exact test, and analysis of variance (ANOVA). Results Aneurysms occurred in 40, 40, 20, and 80% of ApoE null-Ang II mice at 7, 14, 21, and 28 days, respectively. An early and significant rise in MT1-MMP mRNA occurred in ApoE null mice infused with Ang II mice, while there was no significant change in MMP-2 or MMP-9 mRNA levels. Total MMP-2 and MMP-9 activity increased over time in ApoE null mice infused with Ang II, peaking at 28 days (ANOVA, P Conclusions Angiotensin II induces an early increase in aortic MT1-MMP expression with a subsequent increase in MMP-2 and MMP-9 activity. The process by which these changes cause aneurysm formation warrants further investigation.
Adult Mice Maintained on a High-Fat Diet Exhibit Object Location Memory Deficits and Reduced Hippocampal SIRT1 Gene Expression

Mounting evidence has established that diet-induced obesity (DIO) is associated with deficits in hippocampus-dependent memory. The bulk of research studies dealing with this topic have utilized rats fed a high-fat diet as an experimental model. To date, there has been a paucity of research studies that have established whether the memory deficits exhibited in DIO rats can be recapitulated in mice. Moreover, the majority of experiments that have evaluated memory performance in rodent models of DIO have utilized memory tests that are essentially aversive in nature (i.e., Morris water maze). The current study sought to fill an empirical void by determining if mice maintained on a high-fat diet exhibit deficits in two non-aversive memory paradigms: novel object recognition (NOR) and object location memory (OLM). Here we report that mice fed a high-fat diet over 23 weeks exhibit intact NOR, albeit a marked impairment in hippocampus-dependent OLM. We also determined the existence of corresponding aberrations in gene expression within the hippocampus of DIO mice. DIO mice exhibited significant reductions in both SIRT1 and PP1 mRNA within the hippocampus. Our data suggest that mice maintained on a high-fat diet present with impaired hippocampus-dependent spatial memory and a corresponding alteration in the expression of genes that have been implicated in memory consolidation.
Sintering of Fine Oxide Powders: II, Sintering Mechanisms

Conventional and new sintering mechanisms have been investigated using fine powders of CeO 2 and Y 2 O 3 of excellent sinterability. We have verified the validity of Herring's scaling law for 60%-84% relative density and found that it is consistent with grain-boundary-diffusion control. At lower densities, we have found that pores larger than the critical size, in the sense of Kingery and Francois, can still be sintered readily. This is rationalized by a new sintering mechanism based on particle repacking concurrent with particle coarsening, resulting in a higher packing factor. Very fine, surface-active powders that coarsen rapidly are uniquely capable of taking advantage of this new sintering mechanism, which along with their propensity to homogenization, accounts for their remarkable sinterability even at very low green densities.
Comparison of ab initio and density functional theory for alkali peroxynitrite: A highly correlated system with Hartree-Fock instability

Ab initio methods including density functional theory are used to study alkali peroxynitrite (ONOOM, M = Li, Na, and K). The energy, optimized geometries, and vibration frequencies are presented for different conformations of alkali peroxynitrite. The cis−cis (a pseudo-five-membered ring) and trans−cis conformers are minima from a search over the dihedral angles ONOO and NOOM, respectively. Other minima that appear on the potential surfaces depend on the level of theory and the alkali atom studied. All levels of theory predict the cis−cis structures to have the lowest energy, and the stability relative to the trans−cis structures decreases from Li to Na to K. The rotational barrier of cis−cis to trans−cis isomerization is about 20 kcal/mol in ONOOLi, 27 kcal/mol in ONOONa, and 22 kcal/mol in ONOOK. The barriers for the reverse process are 12, 17, and 13 kcal/mol, respectively. Singlet−triplet UHF Hartree−Fock wave function instabilities are found in some of the ONOOM molecules, which lead to poor values f...
Recruitment of a hedgehog Regulatory Circuit in Butterfly Eyespot Evolution

The origin of new morphological characters is a long-standing problem in evolutionary biology. Novelties arise through changes in development, but the nature of these changes is largely unknown. In butterflies, eyespots have evolved as new pattern elements that develop from special organizers called foci. Formation of these foci is associated with novel expression patterns of the Hedgehog signaling protein, its receptor Patched, the transcription factor Cubitus interruptus, and the engrailed target gene that break the conserved compartmental restrictions on this regulatory circuit in insect wings. Redeployment of preexisting regulatory circuits may be a general mechanism underlying the evolution of novelties.
Teaching Note---Learning Outcome Assessment Using an Integrative Assignment on Location Decision Making

Driven by the need to develop an integrative tool to assess learning outcomes for an Association to Advance Collegiate Schools of Business AACSB accredited MBA program, this teaching note presents a unique assignment that requires students to identify appropriate decision modeling tools for the multi-step analysis to support a location decision. The specific value of this assignment is that although the business scenario is simple but nevertheless realistic, developing the supporting analysis requires application and integration of several decision making models. Students need to exhibit the capability to choose appropriate models, to apply them correctly, and to link the results together to support the final, integrative decision. The assignment therefore allows instructors to evaluate two aspects: 1 proficiency with individual modeling tools and 2 the ability to combine such tools for a comprehensive analysis of a realistic business scenario. The assignment is applicable to learning outcomes assessment for learning objectives such as technological and quantitative skills or critical thinking.
Oncogene Expression and Genetic Background Influence the Frequency of DNA Copy Number Abnormalities in Mouse Pancreatic Islet Cell Carcinomas

Quantitative measurements of tumor genome composition show remarkable heterogeneity in tumors arising from the same anatomical location and/or histopathological class and stage. The factors that contribute to genomic heterogeneity are not clear, but germ-line allelic variation and timing of initiating oncogenic events are likely candidates. We investigated these factors by using array comparative genomic hybridization to measure genomic aberrations in genetically engineered mouse models of pancreatic islet cell carcinoma, in which oncogenic transformation is elicited by the SV40 T antigens expressed under the control of the rat insulin promoter (RIP-Tag). Two distinct transgenic RIP-Tag lines, and three polymorphic sublines of one, enabled us to investigate the effects of genetic background and differing age of oncogene induction. Both parameters were found to bias the spectrum of genomic copy number abnormalities. Specifically, the frequency of losing portions of chromosomes 9 and 16 was significantly modulated by genetic background, with the former being lost at highest rates in the FVB/N background and the latter being lost to greatest extent in both FVB/N and C57Bl/6 tumors compared with C3HeB/Fe tumors. The frequency of losing a region of chromosome 6 varied according to the age when tumorigenesis was initiated; loss of chromosome 6 was significantly higher when oncogene expression was first activated in adulthood. These studies illustrate the utility of transgenic animal models for investigation of factors influencing genomic heterogeneity despite the commonalty of target cell type and initiating oncogene.
Energy Use and Greenhouse Gas Emissions from Crop Production Using the Farm Energy Analysis Tool

Using the Farm Energy Analysis Tool (FEAT), we compare energy use and greenhouse gas (GHG) emissions from the cultivation of different crops, highlight the role of sustainable management practices, and discuss the impact of soil nitrous oxide (N2O) emissions and the uncertainty associated with denitrification estimates in the northeastern United States. FEAT is a transparent, open-source model that allows users to choose parameter estimates from an evolving database. The results show that nitrogen fertilizer and N 2 O emissions accounted for the majority of differences between crop energy use and GHG emissions, respectively. Integrating sustainable practices such as no tillage and a legume cover crop reduced energy use and GHG emissions from corn production by 37% and 42%, respectively. Our comparisons of diverse crops and management practices illustrate important trade-offs and can inform decisions about agriculture. We also compared methods of estimating N2O emissions and suggest additional research on this potent GHG.
Distinct neural and neuromuscular strategies underlie independent evolution of simplified advertisement calls.

Independent or convergent evolution can underlie phenotypic similarity of derived behavioural characters. Determining the underlying neural and neuromuscular mechanisms sheds light on how these cha...
5-acyl-2,4-dicyanopyridines from free radical acylation of 2,4-dicyanopyridine

Abstract Free radical acylation of 2,4-dicyanopyridine ( 3 ) in aqueous sulfuric acid furnishes the corresponding C(5) ketones 4 in 60–80% yield, accompanied by trace amounts of the isomeric C(6) ketones 2 .
Synthetic aperture imaging with a virtual source element

Currently ultrasonic imaging is performed in one of two modes: conventional B-scan imaging with a focused transducer or array imaging using beamforming processing to achieve the focus. Conventional B-mode imaging suffers from a limited depth of focus while synthetic aperture imaging is limited by a low signal to noise ratio (SNR). A new technique has been proposed that combines these two techniques to overcome the limited depth of focus. The new technique involves focusing the region beyond the focus of the transducer by considering the focus a virtual element. In this paper, the use of the focus as a virtual element is examined, considering the model for the focus as an element, the use of apodization weights to lower sidelobes, and the SNR of the processed image. Using data collected with tungsten wires in a waterbath, it was found that resolution comparable to the resolution at the focus could be achieved while obtaining an acceptable SNR. Apodization was found to lower the sidelobes, but only at the expense of lateral resolution. With these experiments, the virtual source has been shown to exhibit the same behavior as an actual transducer element in response to synthetic aperture processing techniques.
A flexible protocol for the induction of recipient endometrial cycles in an oocyte donation programme

Synchronization of the availability of good quality oocytes from donors and adequate endometrial maturation of recipients are very important for the success of an oocyte donation programme. A flexible protocol for the endometrial preparation of recipients is important in timing embryo transfer between days 17 and 19 of the cycle ('window of receptivity'). The purpose of this study was to evaluate the effect of the length of oestradiol administration to recipients on pregnancy outcome. Oestrogen administration was 8 mg/day, but its length varied prospectively from 6 to 27 days, followed by the addition of progesterone (100 mg daily i.m.) for 2-4 days according to the availability of good quality oocytes. Pregnancy outcome was evaluated regardless of age, indication for oocyte donation or number of embryos transferred per patient. The pregnancy rate per cycle was comparable when oestradiol was administered from 6 to 11 days before progesterone addition, while it dropped significantly thereafter. The variation in progesterone administration did not affect pregnancy outcome. These findings provide us with a greater flexibility by allowing us to vary oestradiol administration to recipients from 6 to 11 days prior to progesterone, reducing considerably, therefore, the need to cancel embryo transfer because of oocyte unavailability. Thus we can arrange to transfer embryos between days 17 and 19 of the recipient's cycle so as to obtain the best possible clinical outcome.
Projective Controls for 2-DOF Quarter-Car Suspension

Two control schemes for a two-Degree-Of-Freedom quarter-car suspension are studied here. Both schemes use projective controls to approximate a reference state-feedback control law. The first control scheme assumes a reactive suspension-force input generated by nondynamic control components. Since no actuator dynamics are included, the suspension model is 4th order. Static projective controls are utilized to yield both passive and active suspension controls, depending on the measurement structure assumed. The second control scheme assumes two reactive force inputs. The first input is generated by (nondynamic) passive components, the second by an actuator which includes its own first-Order dynamics. In this case, the suspension model is 5th order, since it includes the actuator dynamics. The separation of passive and active components in this control scheme leads to a decentralized control structure. For the example considered, fist-order dynamic projective controllers are introduced in order to stabilize the system.
Adhesiveness of human ligament fibroblasts to laminin.

The adhesiveness of fibroblasts from the human anterior cruciate and medial collateral ligaments to the laminin molecule was studied, with particular emphasis on the intrinsic differences between fibroblasts from the two ligaments. Cellular adhesion strength, adhesion area, laminin concentration, and seeding time were examined. Cell adhesion to laminin anchored with poly-D-lysine to a cleaned cover glass was measured with a micropipette micromanipulation system after seeding. The adhesion strength of fibroblasts from the anterior cruciate ligament to laminin was greater than and significantly different from that of fibroblasts from the medial collateral ligament, depending on the laminin concentration. Fibroblasts from the anterior cruciate ligament also exhibited an increase in adhesion strength, dependent on laminin concentration of as much as 30 μg/ml, at which the laminin receptors were thought to be saturated. Fibroblasts from the medial collateral ligament did not show such an increase except at laminin concentrations of 5–10 μg/ml. There was no significant difference in adhesion area between fibroblasts from the two ligaments except after 45 minutes at a laminin concentration of 40 μg/ml. For both, the adhesion to laminin showed little correlation to seeding time during periods of as long as 60 minutes. Measurements of adhesion area also failed to show a significant correlation to seeding time for fibroblasts from either ligament at laminin concentrations of 20 and 40 μg/ml. Adhesion strength normalized by adhesion area had no correlation to seeding time. With all times taken into account, however, normalized adhesion strength for fibroblasts from the anterior cruciate ligament was approximately two times greater than and significantly different from that for fibroblasts from the medial collateral ligament at laminin concentrations of 20 and 40 μg/ml. Fibroblasts from the anterior cruciate ligament adhere more strongly to laminin than do those from the medial collateral ligament. This study may prove useful in the understanding of fibroblast adhesion to the basal lamina within the extracellular matrix and may provide insight into the natural healing processes of the anterior cruciate and medial collateral ligaments.
Nanocomposite Counter Electrode Materials for Electrochromic Windows

In this paper, we describe our development of a counter electrode material that shows promise in terms of both durability and performance and is grown using common vacuum deposition methods and materials. The counter electrode films are formed by sputter deposition from a composite ceramic lithium, nickel, and tungsten oxide target. Consistent with previous reports, NiO nanocrystallites are observed to form. 12,13 Secondary phases from the other elements present in the sample are not observed, which implies that they act as substitutional or interstitial dopants or segregate to the grain boundaries and form an amorphous layer between the NiO crystallites. Experimental
Royal Art of Benin: The Perls Collection in The Metropolitan Museum of Art

Royal Art of Benin: The Perls Collection in The Metropolitan Museum of Art. Kate Ezra. New York: The Metropolitan Museum of Art and Harry N. Abrams, Inc., 1992. 344pp. 250 illustrations, 84 in full color, glossary, bibliography, index. $60.00 (cloth).
The Theological Anthropology of Young Adult Catholics in Postmodern America

The metaphors and images that the individual holds for God have been neglected in theological anthropology, even though they offer important insights into how the individual builds a foundation of faith, engages in the world spiritually, and participates in religious institutions. The author interviewed young adult Roman Catholics for this study, guided by the following question: What metaphors and images do individuals hold for God, and how do these metaphors and images contribute to an understanding of theological anthropology?
Walkable new urban LEED_Neighborhood-Development (LEED-ND) community design and children's physical activity: selection, environmental, or catalyst effects?

Background Interest is growing in physical activity-friendly community designs, but few tests exist of communities explicitly designed to be walkable. We test whether students living in a new urbanist community that is also a pilot LEED_ND (Leadership in Energy and Environmental Design-Neighborhood Development) community have greater accelerometer-measured moderate-to-vigorous physical activity (MVPA) across particular time periods compared to students from other communities. We test various time/place periods to see if the data best conform to one of three explanations for MVPA. Environmental effects suggest that MVPA occurs when individuals are exposed to activity-friendly settings; selection effects suggest that walkable community residents prefer MVPA, which leads to both their choice of a walkable community and their high levels of MVPA; catalyst effects occur when walking to school creates more MVPA, beyond the school commute, on schooldays but not weekends.
A novel FIR filter design method based on windowing

A simple extension to the window design method is proposed that provides the flexibility to specify independently the passband ripple and stopband ripple. The modification to the routine is based on creating an additive component which, when applied to the filter, can redistribute the concentration of z-plane zeros in the passband and stopband regions of the z-plane. Some examples and comparisons are also presented. >
An antisense approach to phenotype-based gene cloning in Tetrahymena

We report a pioneering approach using Tetrahymena thermophila that permits rapid identification of genes based on their null or hypomorphic phenotypes. This technique involves cell transformation with a library of plasmids that encode 26S ribosomal subunits containing short insertions. The insertions correspond to antisense sequences for a large number of genes. The majority of cells each acquires a single antisense sequence, which silences a single genomic locus. Because the insertion site within the ribosomal sequence is known, the silenced gene is easily amplified. We demonstrate that this approach can be used to identify genes required for dense core granule exocytosis.
umuDC-dnaQ Interaction and Its Implications for Cell Cycle Regulation and SOS Mutagenesis in Escherichia coli

The Escherichia coli SOS-regulated umuDC gene products participate in a DNA damage checkpoint control and in translesion DNA synthesis. Specific interactions involving the UmuD and UmuD' proteins, both encoded by the umuD gene, and components of the replicative DNA polymerase, Pol III, appear to be important for regulating these two biological activities of the umuDC gene products. Here we show that overproduction of the epsilon proofreading subunit of Pol III suppresses the cold sensitivity normally associated with overexpression of the umuDC gene products. Our results suggest that this suppression is attributable to specific interactions between UmuD or UmuD' and the C-terminal domain of epsilon.
On the Dynamical Law of the Ginzburg-Landau Vortices on the Plane

We study the Ginzburg-Landau equation on the plane with initial data being the product of n well-separated +1 vortices and spatially decaying perturbations. If the separation distances are O(e 1 ), e 1, we prove that the n vortices do not move on the time scale O(e 2 λe), λe = o(log 1 e ); instead, they move on the time scale O(e 2 log 1 ) according to the law ˙ x j = ∇x jW, W = ∑l6 j logjxl x jj, x j =( ξ j; η j) 2 R 2 , the location of the j th vortex. The main ingredients of our proof consist of estimating the large space behavior of solutions, a monotonicity inequality for the energy density of solutions, and energy comparisons. Combining these, we overcome the infinite energy difficulty of the planar vortices to establish the dynamical law. c 1999 John Wiley & Sons, Inc.
Trust in virtual teams: towards an integrative model of trust formation

Traditional models of trust have seen trust as being created as a result of a long history of interaction, but recent studies of trust in virtual teams have shown the existence of high initial trust among team members. This paper proposes an integrated model of trust that encompasses both the traditional view of trust and the swift trust found in virtual teams. Based on the dual process theories of cognition, we argue that individuals form trust attitudes via three distinct routes at different stages of a relationship: the peripheral route, the central route, and the habitual route, irrespective. In the initial stages of a relationship when individuals lack information about each other, they rely on peripheral cues (e.g., third party information, social categories, roles, and rules) to form trust. Once individuals have shared history and knowledge of the other party, they use the central route, which involves the assessment of the other party's ability, integrity, and benevolence. Finally, after long periods of shared history in which the individuals develop a habitual pattern of trust, along with possible emotional bonds, they are no longer motivated to deliberately assess trust, and instead simply enact prior trust attitudes via the habitual route. The mediated communication environment predominantly used by virtual teams slows down the progression among the three routes, and increases perceived risk.
Equational inference, canonical proofs, and proof orderings

We describe the application of proof orderings—a technique for reasoning about inference systems-to various rewrite-based theorem-proving methods, including refinements of the standard Knuth-Bendix completion procedure based on critical pair criteria; Huet's procedure for rewriting modulo a congruence; ordered completion (a refutationally complete extension of standard completion); and a proof by consistency procedure for proving inductive theorems.
Nutritional exchange in a tropical tripartite symbiosis II: direct evidence for the transfer of nutrients from host anemone and zooxanthellae to anemonefish

The anemone–anemonefish association is the quintessential symbol of a symbiotic mutualism from the Indo-Pacific waters. Both historical field documentation and extant scientific research advocate that these interactions are fundamental at the level of nutrient exchanges and evolutionary driving forces (natural selection) to facilitate this mutualism. Through the use of 15N and 13C stable isotope tracers, complementary laboratory- and field-based experiments were implemented in the Philippines to investigate the possibility of nutrient transmission from the host anemone, Heteractis crispa and/or endosymbiotic zooxanthellae, to two species of exosymbiotic anemonefishes (Amphiprion clarkii and A. perideraion). Mass spectrometry analyses suggest that 15N and 13C concentrations were significantly higher in tissues of the anemonefishes (intestines, liver, gills, and gonads), anemone host, and zooxanthellae compared with controls. We interpret the presence of 15N and 13C in the anemonefish tissues as direct empirical evidence for the transmission of nitrogen and/or carbon from host anemone and endosymbiotic zooxanthellae to resident anemonefish. These “translocations” and resultant recycling of elements within this classical tripartite relationship highlight the fundamental role of nutrient dynamics in this synergistic symbiosis.
Tailored delivery of active keratinocyte growth factor from biodegradable polymer formulations.

We report the results of a high throughput screening campaign that is aimed to develop a biodegradable polymer-based formulation to deliver active keratinocyte growth factor (KGF) and provide a means to tune the KGF delivery rate. A statistical design strategy was used to prepare and screen a series of polymer blends that were composed of poly(lactic acid) (PLA), poly(glycolic acid) (PGA), and the surfactant sodium bis(ethylhexyl)sulfosuccinate (Aerosol-OT, AOT). Chloroform was the solvent. Our high throughput screening method used a two-tiered assessment strategy. At Level 1, we identified "lead" KFG-loaded formulations that exhibited KGF emission spectra that were the most similar to the native KGF spectrum recorded in buffer. At Level 2, we used steady-state emission and a homogeneous polarization immunoassay strategy to determine the concentration of total and active KGF, respectively, liberated from the lead formulations during biodegradation. After preparing and screening 2500 formulations, we identified several viable, lead formulations. An analysis of the data showed that the combination of PLA, PGA, and AOT were important to yield a high fraction of active KGF upon release from the formulation; no combination of any two together produced an effect as good as the ternary formulation. The optimum formulations that yielded the highest fraction of active KGF upon release had the following general features: PLA/PGA (w/w) near unity, AOT loading of 100-200 mM, water/AOT mole ratio of 10-20, and a pH between 6 and 8. PLA alone cast from chloroform delivered KGF, but that KGF did not bind to anti-KGF antibodies (i.e., it was inactive). We can tune the KGF release kinetics by more than two orders of magnitude while maintaining the KGF activity upon liberation from the formulation by adjusting the PLA molecular weight.