cssi/SciSciGPT-SciSciNet huggingface dataset:
Salicylate, A New Plant Hormone

Centuries ago,theAmerican Indians andancient Greeks independently discovered thattheleaves andbarkofthe willow tree cured aches andfevers. Itwasnotuntil 1828that Johann Buchner, working inMunich, successfully isolated a tiny amountofsalicin, theglucoside ofsalicyl alcohol, which wasthemajorsalicylate inwillow bark(for review seeref. 23). ThenameSA2, fromtheLatin wordSalix forwillow tree, wasgiven tothis active ingredient ofwillow barkbyRaffaele Piria in1838. Thefirst commercial production ofsynthetic SAbeganinGermany in1874.Aspirin, atrade namefor acetylsalicylic acid, wasintroduced bytheBayerCompany in1898andrapidly became oneofworld's best-selling drugs. Inspite ofthefact thatthemodeofmedicinal action of salicylates isasubject ofcontinual debate, theyarebeing usedtotreat humandiseases ranging fromthecommoncold toheart attacks. Because eveninaqueous solutions aspirin undergoes spontaneous hydrolysis toSA,thetwocompounds havesimilar effects inplants andwill betreated together in this review. Salicylic orortho-hydroxybenzoic acid belongs toadiverse
Rectal bleeding in a woman with a thyroid mass

CLINICAL PRESENTATION: (Dr. D. Wiley) A 32-yearold Caucasian woman presented with an enlarging right neck mass. The mass had been present for 2 years and was associated with dysphagia. She has had no hoarseness or symptoms of respiratory compression. She had been clinically euthyroid. She had no history of radiation exposure or therapy. Medical history was significant for a newly diagnosed irondeficient anemia. The patient was adopted after the death of her mother in her mid-thirties. The patient’s adoptive mother stated that her natural mother had a colostomy. There was no known family history of thyroid disease. Review of systems was remarkable for oligomenorrhea, dyspareunia, and hematochezia. On physical examination, the patient had a marfanoid body habitus with a height of 6 0 and a weight of 122#. There were multiple nodules consistent with fibromas located primarily on her face. Her thyroid was nodular with a dominant 6-cm mass in the right lobe. No cervical lymphadenopathy was palpable. Her heart was regular, lungs were clear to auscultation, breasts were without masses, and her abdominal examination benign. Rectal examination was significant for guaiac-positive stool, and no masses were palpable. Laboratory findings at this time included a normal thyroidstimulating hormone level of 0.6 uIU/ml and a hemoglobin level of 13.0 g/dl. A fine-needle aspiration of the right thyroid mass was suspicious for papillary thyroid carcinoma. Colonoscopy identified pancolonic polyposis, consistent with familial adenomatous polyposis. Multiple biopsies throughout the colon and rectum identified tubulovillous and adenomatous polyps on histopathology. An upper endoscopic evaluation identified multiple adenomatous duodenal polyps measuring 1 to 2 mm in size. A computed tomography (CT) of the abdomen and pelvis at this time was unremarkable. Bilateral mammography was negative for malignancy. The patient underwent a total thyroidectomy without complication. Final pathology confirmed a bilateral multifocal papillary carcinoma with the largest lesion measuring 6 cm. There were 4 separate foci, 2 in each lobe. Two of these were classic papillary and the other 2, including the 6-cm lesion, had atypical patterns. These lesions were more solid with less differentiation and the presence of “squamous morules” (Fig. 1). There was no evidence of lymph node metastases.
Specificity in formation of triple-stranded nucleic acid helical complexes: studies with agarose-linked polyribonucleotide affinity columns.

The binding of a variety of deoxyribo and ribo homo- and copolynucleotide complementary duplexes to agarose-linked homopolynucleotide affinity columns has been studied. The results provide information concerning the specificity of recognition of complementary base pairs of nucleic acids through a mechanism that involves triple-helix formation under physiological conditions of ionic strength, pH, and temperature. The method employed made it possible, for the first time, to survey the full range of base triplets conceivable from the canonical nucleic acid bases and, in addition, hypoxanthine and thereby to differentiate between those triplets which can and cannot form. Certain previously observed features of the stereochemistry of double-helical targets for third-strand binding are confirmed, and some unrecognized features are elaborated. These include a general requirement for clusters of purine residues in one strand, protonation of third-strand C residues, the ability of natural third-strand residues to distinguish between A.T/U and G.C base pairs, and a capacity of third-strand (unnatural) I residues to recognize all base pairs within such clusters. Thus, the basis for a third-strand binding code is demonstrated.
Collisionless transport in a stochastic magnetic field

Collisionless transport in stochastic magnetic field configuration is investigated numerically. Results are in reasonable agreement with analytic expressions valid well above stochastic threshold.
Spatial distribution of putative water related features in Southern Acidalia/Cydonia Mensae, Mars

Abstract Many putative water-related features exist in the northern lowlands of Mars. These features may provide clues to the abundance and timing of water or ice that existed there in the past. The Cydonia Mensae and Southern Acidalia area was chosen as the study area owing to the abundance of two of these features: giant polygons and pitted cones. In addition a section of the Deuteronilus shoreline is located there. The abundance and close proximity of the features makes this area an excellent place to study the spatial relationships between these landforms, as well as the morphological characteristics of pitted cones. The features were mapped into a GIS for spatial analyses. The highest densities of pitted cones and giant polygons are adjacent but distinctly separated by a knobby ridge that is surrounded by the Deuteronilus putative shoreline. Pitted cones were measured and examined to determine if a classification by morphology is possible, but the results were inconclusive. Statistical tests on pit-to-cone diameter ratios and tests of surface temperatures of cone material suggest, but do not verify, a single cone origin. The various shapes, sizes, and putative ages of pitted cones may be attributed to temporal variation in emplacement and spatial variation in material properties. Among the possible scenarios put forth for pitted cone genesis on Mars two are likely candidates in Cydonia Mensae: (1) the sublimation of a cold-based glacier, and (2) a buried lens of methane and/or CO2 clathrates.
Micron-Resolution Particle Image Velocimetry

During the past five years, significant progress has been made in the development and application of micron-resolution Particle Image Velocimetry (µPIV). Developments of the technique have extended typical spatial resolutions of PIV from order 1-mm to order 1-µm. These advances have been obtained as a result of novel improvements in instrument hardware and post processing software.
Acyl phosphatase activity of NO-inhibited glyceraldehyde-3-phosphate dehydrogenase (GAPDH): a potential mechanism for uncoupling glycolysis from ATP generation in NO-producing cells

Treatment of glyceraldehyde-3-phosphate - dehydrogenase (GA (GAPDH) with the NO donors S-nitrosoglutathione, 3-morpholinosydnonimine or diethylamine NONOate (diethylamine diazeniumdiolate) in vitro, inhibited its dehydrogenase activity and induced its acyl phosphatase activity. NO-producing cells, in turn, exhibited reduced GAPDH activity, increased glycolysis, and decreased ATP content, synthesis and turnover. These cellular alterations could be explained by the uncoupling of glycolytic flux from substrate level phosphorylation by the acyl phosphatase activity of NO-modified GAPDH.
GYKI 52466 has positive modulatory effects on AMPA receptors.

The 2,3-benzodiazepine derivative GYKI 52466 has been well characterized as a negative modulator of AMPA-type glutamate receptors. The present study re-examined the effects of GYKI 52466 on AMPA receptor-mediated currents in patches excised from pyramidal neurons in the hippocampal CA1 field and found that this drug has positive modulatory effects in addition to its receptor blocking action. A low concentration of GYKI 52466 (10 μM) reliably increased the steady-state current by about three-fold, while the peak current was reduced by 30% only. Higher drug concentrations produced parallel reductions in both the steady-state and peak currents. The increase in the steady-state current was not accompanied by a change in the deactivation time constant and thus, is more likely to result from a change in desensitization than a slowing of channel closing. The results indicate that GYKI 52466 modulates AMPA receptor-mediated currents in a complex manner, perhaps by acting through more than one binding site.
Voxel sensitivity function description of flow-induced signal loss in MR imaging: implications for black-blood MR angiography with turbo spin-echo sequences.

The conditions in which the image intensity of vessels transporting laminar flow is attenuated in black-blood MR angiography (BB-MRA) with turbo spin-echo (TSE) and conventional spin-echo (CSE) pulse sequences are investigated experimentally with a flow phantom, studied theoretically by means of a Bloch equation-voxel sensitivity function (VSF) formalism, and computer modeled. The experiments studied the effects of: a) flow velocity, b) imaging axes orientation relative to the flow direction, and c) phase encoding order of the TSE train. The formulated Bloch equation-VSF theory describes flow effects in two-dimensional (2D)- and 3D-Fourier transform magnetic resonance imaging. In this theoretical framework, the main attenuation mechanism instrumental to BB-MRA, i.e., transverse magnetization dephasing caused by flow in the presence of the imaging gradients, is described in terms of flow-induced distortions of the individual voxel sensitivity functions. The computer simulations predict that the intraluminal homogeneity and extent of flow-induced image intensity attenuation increase as a function of decreasing vessel diameter, in support of the superior image quality achieved with TSE-based BB-MRA in the brain.
Endovascular Rescue of a Thoracoabdominal Fenestrated Endograft Presenting With Combined Type 1 and Type 3 Endoleaks From Aortic Graft Migration and Visceral Stent Separation

Background To describe successful endovascular rescue of a prior fenestrated endograft repair of a thoracoabdominal aneurysm that presented with combined type I and type III endoleaks due to aortic stent migration and subsequent visceral stent dislodgement. Method A 67 year old male with significant cardiac dysfunction and chronic renal insufficiency underwent fenestrated endograft repair of a 7 cm type IV thoracoabdominal aneurysm with 4 fenestrations in 2008. He presented with acute onset abdominal pain. CT scan revealed type I and III endoleaks with aneurysm enlargement to 10 cm. Angiography revealed the superior mesenteric and renal artery stents within their target vessels, but separation from their respective fenestrations in the aortic graft with significant gaps (>15 mm) and resultant type 3 endoleaks. The celiac artery stent was fractured; part of it remained within the celiac artery and part within the celiac fenestration and a 30 mm craniocaudal gap between the two pieces. All 4 visceral stents were patent with intact distal flow. A large proximal type 1 endoleak was also seen. All fenestrations were successfully catheterized via percutaneous approach and gaps were successfully bridged with covered stents eliminating the type III endoleaks. A thoracic endograft was placed proximally to repair the type I endoleak. Results Completion angiography demonstrated successful resolution of the type I and type III endoleaks with flow through all 4 branches and tertiary vessels. Conclusion Endovascular rescue of prior branched endografts is a feasible solution in patients at prohibitive risk for open surgery.
Petrology of Martian meteorite Northwest Africa 998

Nakhlite Northwest Africa (NWA) 998 is an augite-rich cumulate igneous rock with mineral compositions and oxygen isotopic composition consistent with an origin on Mars. This 456- gram, partially fusion-crusted meteorite consists of (by volume) ~75% augite (core composition Wo39En39Fs22), ~9% olivine (Fo35), ~7% plagioclase (Ab61An35) as anhedra among augite and olivine, ~3.5% low-calcium pyroxenes (pigeonite and orthopyroxene) replacing or forming overgrowths on olivine and augite, ~1% titanomagnetite, and other phases including potassium feldspar, apatite, pyrrhotite, chalcopyrite, ilmenite, and fine-grained mesostasis material. Minor secondary alteration materials include iddingsite associated with olivine (probably Martian), calcite crack fillings, and iron oxide/hydroxide staining (both probably terrestrial). Shock effects are limited to minor cataclasis and twinning in augite. In comparison to other nakhlites, NWA 998 contains more low-calcium pyroxenes and its plagioclase crystals are blockier. The large size of the intercumulus feldspars and the chemical homogeneity of the olivine imply relatively slow cooling and chemical equilibration in the late- and post-igneous history of this specimen, and mineral thermometers give subsolidus temperatures near 730 °C. Oxidation state was near that of the QFM buffer, from about QFM-2 in earliest crystallization to near QFM in late crystallization, and to about QFM + 1.5 in some magmatic inclusions. The replacement or overgrowth of olivine by pigeonite and orthopyroxene (with or without titanomagnetite), and the marginal replacement of augite by pigeonite, are interpreted to result from late-stage reactions with residual melts (consistent with experimental phase equilibrium relationships). Apatite is concentrated in planar zones separating apatite-free domains, which suggests that residual magma (rich in P and REE) was concentrated in planar (fracture?) zones and possibly migrated through them. Loss of late magma through these zones is consistent with the low bulk REE content of NWA 998 compared with the calculated REE content of its parent magma.
Individual Differences in Emotionality in Infancy

In this multimethod investigation of early emotionality, we observed 112 8- to 10-month-olds' responses to standard procedures consisting of multiple brief episodes that elicited joy, fear, anger, and discomfort to aversive stimulation. We obtained parental reports about the infants' temperament and observed their emotional tone during naturalistic interactions with their mothers. Parameters of emotional response to the standard procedures (latency, discrete behaviors, and average and peak intensity across facial, vocal, and bodily channels) cohered strongly within each episode. To a lesser extent and with the exception of anger, they also cohered across episodes targeting the same emotion. The four emotions appeared orthogonal, except for the peak intensity of response, which cohered modestly across the 3 negative emotions. The emotionality measures converged to some extent: responses to the standard procedures and father-reported temperament related meaningfully to the infant's emotional tone in mother-child interactions. As predicted, infants' capacity for focused or effortful attention was modestly associated with better modulated negative emotionality.
Capsaicin treatment differentially affects feeding suppression by bombesin-like peptides

Peripheral administration of bombesin (BN) and the related mammalian peptides, gastrin-releasing peptide (GRP) and neuromedin B (NMB), suppress food intake in rats. To examine whether all BN-like peptides utilize the same neural pathways to reduce feeding, rats were treated on postnatal day 2 with the injection vehicle or capsaicin, a neurotoxin that damages a subset of visceral afferent fibers. When rats reached adulthood, we compared the ability of a dose range of systemically administered BN, GRP18-27 and NMB to reduce intake of a 0.5 kcal/ml glucose solution in a short-term feeding test. Our results demonstrate that capsaicin treatment abolished or attenuated the suppression of glucose intake produced by BN and NMB but had no effect on the ability of GRP to reduce feeding. These results suggest that different neural substrates underlie the anorexic effects of peripherally administered BN-like peptides.
Oxidative-stress induced protein glutathione mixed-disulfide formation in the ocular lens

Abstract The biochemistry of protein-glutathione mixed disulfide formation in the ocular lens was examined by 13 C-NMR spectroscopic measurements of glutathione oxidative metabolism in intact rabbit lenses maintained in organ culture. Lenticular amino acid uptake and glutathione biosynthetic mechanisms were employed to facilitate the incorporation of L-[3- 13 C]cysteine from the incubation medium into the cysteinyl residue of glutathione. Subsequent exposure to increasing levels of oxidative stress induced by tert -butylhydroperoxide resulted in decreased levels of ([3- 13 C]cysteinyl)-glutathione and a loss of 13 C NMR resonance intensity, a reflection of protein-glutathione mixed disulfide formation. The rate of ([3- 13 C]cysteinyl)-glutathione loss depended on the concentration of tert -butylhydroperoxide; 13 C-labeled oxidized glutathione was observed only at the highest concentration (2 mM) of oxidant tested. Removal of the oxidative stress led to a partial recovery of ([3- 13 C]cysteinyl)-glutathione levels and 13 C resonance intensity. Recovery was significantly enhanced by the addition of 2-mercaptoethanol. The mechanism of protein-glutathione adduct formation was further characterized by the in vitro monitoring of the reaction of oxidized glutathione with bovine lens γ-II crystallin protein using proton NMR spectroscopy. These experiments provided insight into the role of the cellular glutathione redox-couple, [GSH]/[GSSG], in maintaining reduced protein thiol groups, and suggested that protein-glutathione adduct formation may function as a mechanism for modulating the glutathione redox buffer under conditions of oxidative stress in ocular tissue. In addition, the results demonstrate the feasibility of direct chemical reduction of protein-glutathione disulfide bonds in vivo which may reflect a mechanism for the inhibition of disulfide-linked light scattering protein aggregate formation.
The microbial community at Laguna Figueroa, Baja California Mexico - From miles to microns

The changes in the composition of the stratified microbial community in the sediments at Laguna Figeroa following floods are studied. The laguna which is located on the Pacific coast of the Baja California peninsula 200 km south of the Mexican-U.S. border is comprised of an evaporite flat and a salt marsh. Data collected from 1979-1983 using Landsat imagery, Skylab photographs, and light and transmission electron microscopy are presented. The flood conditions, which included 1-3 m of meteoric water covering the area and a remanent of 5-10 cm of siliciclastic and clay sediment, are described. The composition of the community prior to the flooding consisted of Microcoleus, Phormidium sp., a coccoid cynanobacteria, Phloroflexus, Ectothiorhodospira, Chloroflexus, Thiocapsa sp., and Chromatium. Following the floods Thiocapsa, Chromatium, Oscillatora sp., Spirulina sp., and Microcoleus are observed in the sediments.
Brief clinical report: dysgerminoma in a patient with the syndrome of gonadal dysgenesis with a 45,X karyotype.

A 19-year-old woman with the Ullrich-Turner syndrome presented with a mass filling her entire pelvis. The tumor was a dysgerminoma. Only one other patient with a 45,X chromosome constitution has been reported with this form of malignancy.
Beam: a mobile application to improve happiness and mental health

In this paper, we present beam, a mobile application that uses random acts of kindness to analyze and improve the mental health of its users. The concept was developed using an iterative, user-centered design process that included contextual inquiry, surveys, low and high-fidelity prototypes, and usability testing. Based on our initial research findings, we found that users tend to be pessimistic and focus on stress and negativity. We designed a mobile application that focuses on positive action and self-reflection to improve individual mental health. We used a combination of theory, design, and user research to influence users to become more optimistic -- linking the use of the application with mental health and mood improvements.
On the law of fatigue crack layer propagation in polymers

A generalized theory of fatigue crack propagation in polymers is presented. The theory accounts for crack propagation through root craze extension accompanied by the dissemination of micro defects around the main crack thereby describing a crack layer (CL) system. In addition to the conventional crack length(l), the CL width(w) is introduced as another kinematic parameter. Applying the principle of minimum thermodynamic forces, evolution of l and w is formulated in terms of reciprocal thermodynamic forces. Accordingly the law of Fatigue Crack Layer Propagation (FCLP) is derived in the following dimensionless form where N is the number of cycles, λ ≈ l(N)/l*; l* being the critical CL length, ω = w(l)/w*; w* being the value of w corresponding to l*, β′ and Q′ are energy dissipation and heat evolution functions, respectively. A version of this law provides good description of growth rates from published data.
Education for Technical Services Librarians: Courses Taught at Accredited Library and Information Science Degree Programs

Library science education is explored through an investigation of program websites, an instructor survey, and review of course syllabi. The purpose of this study was to acquire a representation of technical services education offered through ALA accredited programs in the United States, Canada, and Puerto Rico. This study reviewed program websites for courses associated with technical services responsibilities, such as cataloging, acquisitions, serials, collection management, preservation, and systems. A survey was sent to library and information science instructors to closely investigate institution curricula and the prevalence of technical services courses, their means of delivery, subject coverage, and faculty member status.
The significance of U–Pb zircon dates in lower crustal xenoliths from the southwestern margin of the Kaapvaal craton, southern Africa

The combination of high precision ID-TIMS U–Pb geochronology with cathodoluminescence (CL) imaging and spatially resolved microsampling of zircon provides a high fidelity record of the temporal evolution of samples of the middle and lower crust. A suite of xenoliths exhumed in Cretaceous kimberlites at the southwestern margin of the Kaapvaal craton, including eclogite, granulite, amphibolite, and greenschist-facies plutonic rocks, are the subject of these detailed zircon studies. CL imaging demonstrates the complexity of chemical and growth structure in single zircons, and highlights the importance of sampling on an intragrain scale to extract end-member ages for zircon growth events. For these diverse metamorphic rocks, linking the zircon chronology to geologic events and processes requires an understanding of the kinetics and thermodynamics of zircon stability during metamorphism. Using an empirical approach, we attempt to relate zircon crystallization, dissolution, and regrowth to metamorphic conditions through a detailed analysis of zircon chemical zonation patterns, mineral inclusions, and petrography. These lines of evidence indicate the crystallization of zircon under P–T conditions ranging from eclogite through greenschist facies. We discuss four examples of this approach: (1) At the lowest grade of metamorphism examined, primary igneous zircon (1900 Ma) in a syenite xenolith from the Klipfontein-08 kimberlite underwent two episodes (1015 and 964 Ma) of probable fluid-mediated resorption and reprecipitation in the greenschist facies. (2) An upper amphibolite facies xenolith from the Markt kimberlite contains two distinct populations of blocky and fir-tree sector-zoned zircon which are suggested to date prograde hornblende breakdown reactions (∼1107 Ma) and melt infiltration under retrograde metamorphic conditions (∼1092 Ma), respectively. (3) At granulite-facies, metamorphic zircon crystallized at ∼1114 Ma during prograde reactions involving hornblende breakdown in a granulite xenolith also from the Markt kimberlite. Later (∼960 Ma) zircon resorption followed by minor secondary crystallization occurred in both the amphibolite and granulite xenoliths during retrograde greenschist facies reactions, possibly enhanced by fluids. (4) In a much older episode of eclogite facies metamorphism recorded in a xenolith from the Lovedale kimberlite, zircon crystallized with the peak metamorphic mineral assemblage, or possibly early on the cooling path, in the Late Archean (∼2630 Ma). Each of these examples provides unique information regarding the evolution of the Kaapvaal craton, while the links to metamorphic reactions and P–T conditions clarify the interpretation of zircon dates obtained from these samples of the middle to lower crust.
Enhanced Heat Transfer for Boiling of a Refrigerant on a Micro-Structured Cylindrical Surface and Effect of Saturation Temperature

Boiling on the outside surface of cylindrical tubes is an important heat transfer process widely used in industry applications. It is known that boiling heat transfer coefficient increases with increasing saturation temperature. However, a quantitative measure of saturation temperature effect on boiling heat transfer is not readily available, especially for boiling on surfaces of microstructures. This work was motivated by the need to predict evaporator performance in a chiller while taking into account the effect of saturation temperature on boiling heat transfer coefficient. Experiments of boiling of refrigerant R123 on the micro-structured outside surface of an evaporator tube have been performed at three saturation temperatures in the range of 4.4 to 17.8°C. Water flows inside the test tubes and provides heat to the refrigerant for boiling. In addition, experiments of R123 boiling on smooth cylindrical tubes have been performed at the saturation temperature 4.4°C to provide a baseline to quantify the enhancement in boiling heat transfer due to microstructures on the test tubes. For boiling on the micro-structured surface, the boiling heat transfer coefficient increases by nearly 15% for the temperature range considered in this work. Measurements also showed that heat transfer coefficient for boiling on the test tubes of micro-structures is 12.3 times higher than boiling on the smooth surface. The Cooper correlation over-predicted by 40% the boiling heat transfer coefficient on the smooth cylindrical surface, but significantly under-predicted the performance for boiling on the tubes of micro-structures. It is found that the prediction of Cooper correlation multiplied by an enhancement factor 7.9 has a good agreement with measured heat transfer coefficient for boiling on the tubes of micro-structures at all the three saturation temperatures. Visual observations indicated that bubble departure characteristics on the micro-structured surface are different from those on the smooth surface. In addition to promoted bubble nucleation by re-entrant cavities on the micro-structured surface, the different bubble departure characteristics also contribute to the enhancement of boiling performance.Copyright © 2010 by ASME
Hall number in YbRh 2 Si 2

Recent experimental studies have revealed an abrupt change in the Hall number at a field tuned quantum critical point in the heavy fermion magnet YbRh2Si2. We investigate this by calculating the local density band structure for this metal and the appropriate transport integrals. We find the Fermi surface to be multi-sheeted with the two largest sheets having opposite sign contributions to the Hall number. Small changes in the f electron occupation are sufficient to reproduce the observed large change in the Hall number. This suggests that YbRh2Si2 may be the first example of a quantum critical valence fluctuator.
Efficiency and fairness: Compensation for takings

Abstract Fairness as well as efficiency is an important aspect of compensation if land is condemned for public use. Much of the economics literature focuses on the efficiency aspect of compensation while equity considerations are given far smaller space. For a limited set of public projects, those for which the entire benefit is captured in land values, compensation at the market value of non-taken land is shown to induce efficient choices by both the bureau that makes the taking choice and the landowners whose property is affected by those choices. The compensation rule is self-financing if the bureau’s expenditures are financed entirely by an ad valorem property tax. The generality of the conclusion is limited by the motives of the bureau and the order in which the decisions are made.
Rapid Exploration of the Design Space During Automatic Generation of Kalman Filter Code

State estimation is a core capability for autonomous systems such as satellites and planetary rovers. Kalman filters provide a computationally efficient way to determine the values of state variables (e.g. position, velocity) from noisy measurements. The Automated Software Engineering group at NASA Ames Research Center has previously developed a number of systems for generating program code in NASA-relevant domains, including AMPHION/NAIF (Whittle et al., 2001) for generating code for mission planning and AUTOBAYES (Fischer and Schumann, 2003) for generating data analysis code. In this paper, we outline a program generation system, AUTOFILTER (Whittle and Schumann, 2005), which has been developed at NASA Ames Research Center. AUTOFILTER synthesizes (i.e. generates) Kalman filter code. It takes as input a textual specification - a description of the mathematical model underlying the Kalman filter - and automatically generates code suitable for compilation using MATLAB libraries (for prototyping and testing the filter) or standalone C code (for deploying the filter). We describe how AUTOFILTER assists the iterative development of Kalman filters in various ways: permitting changes in the mathematical model underlying the filter to be rapidly realized as code and tested, different Kalman filters to be synthesized from the same model, code automatically assessed for computational performance, and approximating assumptions applied to the code in order to improve efficiency. AUTOFILTER provides assistance for ensuring that the generated code is correct by generating program documentation and correctness certificates in addition to the code itself
The effect of platinum on Al diffusion kinetics in β-NiAl: Implications for thermal barrier coating lifetime

First-principles density functional theory calculations are used to study Al diffusion in β-NiAl. The activation energy and diffusion constant pre-exponential factors are calculated for five previously postulated Al diffusion mechanisms: next-nearest-neighbor Al jumps, the triple defect mechanism and three variants of the six-jump cycle mechanism beginning with an Al vacancy. We predict that the triple defect mechanism has the lowest activation energy and is the mechanism by which Al diffusion occurs in NiAl. In order to elucidate why Pt has a beneficial effect on thermal barrier coating lifetime, the effect of Pt on each of these mechanisms is also examined. In all cases, Pt decreases the diffusion activation energy, which should enhance Al diffusion in the coatings.
Global structural optimization of Si magic clusters on the Si(1 1 1) 7 × 7 surface

Abstract We performed global structural optimization using a genetic algorithm in combination with tight-binding and first-principles calculations to study the structures of the magic clusters on the Si(1 1 1) 7 × 7 surface. Our calculations show that the magic cluster observed in scanning tunneling microscopy (STM) experiment [I.S. Hwang, M.S. Ho, T.T. Tsong, Phys. Rev. Lett. 83 (1999) 120] consists of eight Si atoms on the faulted half of the Si(1 1 1) 7 × 7 surface. Simulated STM images of our Si magic cluster exhibit a ring-like feature similar to STM experiments.
The Crystal Structure of Synechocystis Hemoglobin with a Covalent Heme Linkage

The x-ray crystal structure of Synechocystis hemoglobin has been solved to a resolution of 1.8 A. The conformation of this structure is surprisingly different from that of the previously reported solution structure, probably due in part to a covalent linkage between the heme 2-vinyl and His117 that is present in the crystal structure but not in the structure solved by NMR. Synechocystis hemoglobin is a hexacoordinate hemoglobin in which the heme iron is coordinated by both the proximal and distal histidines. It is also a member of the "truncated hemoglobin" family that is much shorter in primary structure than vertebrate and plant hemoglobins. In contrast to other truncated hemoglobins, the crystal structure of Synechocystis hemoglobin displays no "ligand tunnel" and shows that several important amino acid side chains extrude into the solvent instead of residing inside the heme pocket. The stereochemistry of hexacoordination is compared with other hexacoordinate hemoglobins and cytochromes in an effort to illuminate factors contributing to ligand affinity in hexacoordinate hemoglobins.
Multiscale Impacts of Variable Heating in Climate

Abstract While it is obvious that the mean diabatic forcing of the atmosphere is crucial for maintaining the mean climate, the importance of diabatic forcing fluctuations is less evident in this regard. Such fluctuations do not appear directly in the equations of the mean climate but affect the mean indirectly through their effects on the time-mean transient-eddy fluxes of heat, momentum, and moisture. How large are these effects? What are the effects of tropical phenomena associated with substantial heating variations such as ENSO and the MJO? To what extent do variations of the extratropical surface heat fluxes and precipitation affect the mean climate? What are the effects of the rapid “stochastic” components of the heating fluctuations? Most current climate models misrepresent ENSO and the MJO and ignore stochastic forcing; they therefore also misrepresent their mean effects. To what extent does this contribute to climate model biases and to projections of climate change? This paper provides an assess...
Experimental studies of atmosphere-surface interactions on Venus

Abstract We review the sulfur cycle, oxidation state of the surface and near-surface atmosphere, and the decomposition rate of fossil hydrous minerals on the surface of Venus. For each of these chemical weathering processes we discuss what has been learned and what key questions remain unanswered. We focus on these three types of atmosphere-surface interactions because they appear to play major roles in determining the composition of the atmosphere, clouds, and the surface, e.g. by serving as a sink for SO 2 , by controlling the extent and rate of basalt oxidation, or by acting as a sink/source for atmospheric water. Unfortunately, no direct mineralogical data exist for the Venusian surface. Currently, the only way to study atmospheric-surface chemistry on Venus is through laboratory experiments. The results from these experiments will help guide the design of future spacecraft experiments that could make direct mineralogical observations by using techniques such as XRB and/or imaging infrared reflectance spectroscopy. These experimental results along with direct mineralogical data could prove or invalidate models proposed over the years.
Ultrafast solid–liquid–vapor phase change in a thin gold film irradiated by multiple femtosecond laser pulses

Phase change processes including melting, vaporization and resolidification during the multiple femtosecond laser pulses irradiations on a thin gold film are investigated numerically. A two-temperature model is coupled with the phase interface track methods to describe the temperature variation and the solid–liquid and liquid–vapor interface evolutions. The relationship between the maximum vaporization temperature and melting depth, ablation depth are analyzed and compared with that of the single pulse irradiation. It is found that for two pulses irradiation, if deeper melting depth is desirable, the second pulse should be launched as soon as the melting depth induced by the first pulse reaches to the maximum. In comparison to a single pulse irradiation resulting in the same lattice temperature, this two-pulse approach leads to a greater melting depth. For laser irradiation with more than two consecutive pulses, if the total laser fluence remains a constant, larger pulse number and longer separation times between pulses leads to a smaller melting depth. However, the melting depth is much deeper compared to that by induced by a single pulse that causes the same lattice temperature.
Middle Pleistocene Climate Change in the Colorado Rocky Mountains Indicated by Fossil Mammals from Porcupine Cave

Fossiliferous sediments from The Pit Locality in Porcupine Cave, Park County, Colorado, span multiple glacial and interglacial cycles between ca. 800,000 and 400,000 yr B.P. at 2900 m elevation. The uppermost cycle probably represents oxygenisotope glacial Stage 12 (stratigraphic Levels 4 and 3) and interglacial Stage 11 (Levels 3, 2, and 1) as determined by arvicoline biostratigraphic data that place the sequence between 487,000 and 365,000 yr B.P. A no-analog assemblage comprising the bog lemming Mictomys meltoni (of the M. borealis lineage) and the sagebrush vole Lemmiscus curtatus (=Lagurus curtatus) characterizes both the glacial and the interglacial deposits. Climatographs for these two species suggest that, compared to present conditions, the following local climatic limits can be imposed on oxygenisotope Stages 12 and 11: (1) January effective moisture was greater, resulting from average temperatures of at least 5°C cooler and/or at least 15 mm more precipitation; (2) January solar radiation was lower by at least 75 Langleys; (3) effective July solar radiation might have been lower by at least 50 Langleys. Seasonal temperature extremes were not necessarily different from those of the present, but seasonal precipitation was more equable. Relative abundance of mammal taxa and sedimentological data indicate that aridity increased at the onset of the interglacial.
Role of the siderophore azotobactin in the bacterial acquisition of nitrogenase metal cofactors.

Fixation of dinitrogen by soil bacteria is catalyzed by the enzyme nitrogenase which requires iron, molybdenum, and/or vanadium as metal cofactors. Under conditions of iron deficiency, the ubiquitous N2-fixing bacterium Azotobacter vinelandii produces azotobactin, a fluorescent pyoverdine-like compound which serves as a siderophore. Azotobatin’s hydroxamate, catechol, and α-hydroxy-acid moieties endow it with a very high affinity for FeIII, and the Fe complex is taken up by the bacterium. Here we show that azotobactin also serves for the uptake of Mo and V. Azotobactin forms strong complexes with molybdate and vanadate and the complexes are taken up by regulated transport systems. The kinetics of complexation of molybdate and vanadate by azotobactin are faster than the complexation of FeIII, which is either precipitated or bound to strong complexing agents. As a result of this kinetic advantage, the Mo and V complexes of azotobactin form despite the higher affinity of the compound for Fe, which is present...
Ammonia, oxidation leaching of chalcopyrite —reaction kinetics

The reaction for the ammonia, oxidation leaching of chalcopyrite, CuFeS2 + 4NH3 + 17/4 O2 + 2 OH- ⇌ Cu(NH3)+2 42 + l/2Fe2O3 + 2 SO4 + H2O was studied using monosize particles in an intensely stirred reactor under moderate pressures to determine the important chemical factors which govern the kinetic response of the system. The reaction kinetics were studied at dilute solid phase concentration so that oxygen transport at the gas/liquid interface would not limit the rate. A catalytic electrochemical surface reaction was shown to control the reaction kinetics with the reaction rate determined by the following equation derived from electrochemical considerations: dα/dl=127 f/do (OH- 1/2 (k1PO1/1+k2PO1 (k1+k2(Cu+2)o+k’2α)(1-α)2/3 (K P 1/2 Excellent agreement between theory and experiment was obtained both with regard to apparent reaction orders for oxygen, cupric, and hydroxyl, and with regard to geometric factors that influence the reaction rate. Further support for the reaction mechanism included an activation energy of approximately 10 kcal/mole obtained under a variety of experimental conditions and the fact that the initial reaction rate constant was several orders of magnitude less than predicted mass transfer coefficients.
Tomato juice, chocolate drink, and other fluids suppress volitional drinking of alcohol in the female Syrian golden hamster.

Abstract Although the hamster generally prefers alcohol at a level similar to that of the rat or mouse selectively bred to consume alcohol, the drinking hamster demonstrates neither physical dependence on alcohol nor elevated blood levels of alcohol, which are two typical criteria characterizing an animal model of alcoholism. The present investigation was designed to determine whether a third criterion of an animal model (i.e., consumption of high levels of alcohol in the presence of a palatable fluid, fulfilled by the P rat) would be met by the female Syrian golden hamster ( Mesocricetus auratus ). A standard 3-bottle preference test was undertaken in 6 female hamsters over an 11 day period, in which water was presented in one tube and, in a second tube, a v/v solution of alcohol which was increased in concentration from 3% to 50% on each day as follows: 3%, 5%, 7%, 9%, 12%, 15%, 20%, 25%, 30%, 40%, and 50%. Then each hamster was offered its individually determined, maximally preferred concentration of alcohol for 4–8 days, which was 20%, 25%, or 30% alcohol. The mean absolute intake of alcohol during this period was 17.9 ± 1.1 g/kg per day, whereas the mean proportion of alcohol to total fluid was 0.68 ± 0.05. Then over a 4-day interval, a solution of tomato juice, peach juice, mango juice, dextrose and a chocolate beverage (Ensure Plus), all made isocaloric to the alcohol solutions with dextrose, was placed in the third tube simultaneously with water and the individually preferred concentration of alcohol. The results showed that each of the palatable fluids reduced significantly the intake of alcohol of the hamsters below that of the preferred concentration selected during each test sequence. The chocolate drink reduced the intake of alcohol most potently, with the mean intake falling by more than 50% to 8.0 ± 0.4 g/kg per day. Interestingly, this suppression of alcohol intake did not differ significantly from that reported in hamsters administered pharmacological agents including kudzu derivatives. Since a palatable and/or nutritious fluid acts to attenuate drinking, the hamster may not represent a valid animal model for exploring the therapeutic utility of drugs for alcohol abuse or alcoholism.
Genetic polymorphisms in host antiviral genes: associations with humoral and cellular immunity to measles vaccine.

Abstract Host antiviral genes are important regulators of antiviral immunity and plausible genetic determinants of immune response heterogeneity after vaccination. We genotyped and analyzed 307 common candidate tagSNPs from 12 antiviral genes in a cohort of 745 schoolchildren immunized with two doses of measles–mumps–rubella (MMR) vaccine. Associations between SNPs/haplotypes and measles virus-specific immune outcomes were assessed using linear regression methodologies in Caucasians and African-Americans. Genetic variants within the DDX58 /RIG-I gene, including a coding polymorphism (rs3205166/Val800Val), were associated as single-SNPs ( p ≤ 0.017; although these SNPs did not remain significant after correction for false discovery rate/FDR) and in haplotype-level analysis, with measles-specific antibody variations in Caucasians (haplotype allele p -value = 0.021; haplotype global p -value = 0.076). Four DDX58 polymorphisms, in high LD, demonstrated also associations (after correction for FDR) with variations in both measles-specific IFN-γ and IL-2 secretion in Caucasians ( p ≤ 0.001, q = 0.193). Two intronic OAS1 polymorphisms, including the functional OAS1 SNP rs10774671 ( p = 0.003), demonstrated evidence of association with a significant allele-dose-related increase in neutralizing antibody levels in African-Americans. Genotype and haplotype-level associations demonstrated the role of ADAR genetic variants, including a non-synonymous SNP (rs2229857/Arg384Lys; p = 0.01), in regulating measles virus-specific IFN-γ Elispot responses in Caucasians (haplotype global p -value = 0.017). After correction for FDR, 15 single-SNP associations (11 SNPs in Caucasians and 4 SNPs in African-Americans) still remained significant at the q -value In conclusion, our findings strongly point to genetic variants/genes, involved in antiviral sensing and antiviral control, as critical determinants, differentially modulating the adaptive immune responses to live attenuated measles vaccine in Caucasians and African-Americans.
Recapitulation of the hairless mouse phenotype using catalytic oligonucleotides: implications for permanent hair removal.

Ribozyme technology is widely used to target mRNA in a sequence-specific fashion and thus change the expression pattern of cells or tissues. While the goal of mRNA targeting is usually the cleavage of mutant mRNAs with the prospect of gene therapy for inherited diseases, in certain instances, targeting of wild-type genes can be used therapeutically. Lack of expression of the mouse hairless gene due to inherited mutations leads to the complete and irreversible loss of hair known as atrichia. We designed this study to recapitulate the hairless phenotype in a restricted manner by topical application of deoxyribozyme-targeting molecules to specifically cleave the mouse hairless mRNA. Histological samples taken from treated skin at different times demonstrated a decreased number of hair follicles, an involution of the remaining follicles, a separation of the dermal papillae, and the presence of dermal cysts, all characteristics of the hairless phenotype, but not normally present in the skin of C57B1/6 J mice. In this study, we successfully recapitulated the hairless phenotype using topically applied target-specific catalytic oligonucleotides designed to cleave the mouse hairless mRNA. Our results demonstrate the feasibility of using ribozyme technology to alter the gene expression in the skin via topical application and provide proof of principle for the development of this strategy for permanent hair removal.