cssi/SciSciGPT-SciSciNet huggingface dataset:
Mergers of Black Holes in the Galactic Center

We present the results of three-body simulations focused on understanding the fates of intermediate-mass black holes (IBHs) that drift within the central 0.5 pc of the Galaxy. In particular, we modeled the interactions between pairs of 4000 M☉ black holes as they orbit a central black hole (CBH) of mass 4 × 106 M☉. The simulations performed assume a Schwarzschild geometry and account for Chandrasekhar dynamical friction as well as acceleration resulting from energy lost due to gravitational radiation. We found the branching ratio for one of the orbiting IBHs to merge with the CBH was 0.95 and is independent of the inner IBH's initial eccentricity as well as the rate of sinking. This, coupled with an infall rate of ~107 yr for an IBH to drift into the Galactic center, results in an IBH-CBH merger every 11 Myr. Lastly, we found that the IBH-IBH-CBH triple-body system "resets" itself, in the sense that a system with an inner IBH with an initially circular orbit generally left behind an IBH with a large eccentricity, whereas a system in which the inner IBH had a high eccentricity (e0 ~ 0.9) usually left a remnant with low eccentricity. Branching ratios for different outcomes are also similar in the two cases.
Investigation of impurities and laser-induced damage in the growth sectors of rapidly grown KDP crystals

We report the experimental results of impurity contamination and laser-induced damage investigations on rapidly grown potassium dihydrogen phosphate (KDP) crystals. Using absorption spectroscopy and chemical analysis, we determined the impurity distribution in the different growing sectors of KDP single crystals. The level of impurity was dependent on the starting materials and growth rate. We also studied the influence of impurities on the laser-induced damage in fast grown KDP. The laser damage threshold in the impurity- rich prismatic sector is same as in the high purity pyramidal sector within the experimental error. Meanwhile, the laser damage threshold (LDT) at the boundary of the prismatic and pyramidal sectors is less than half of that in the bulk. Furthermore, we found that the thermal annealing of the crystal eliminated the weakness of this sector boundary and increased its LDT to the same level as in the bulk of the crystal. Our result suggests that laser damage occurred in the vicinity of a high, localized strain field.
Biochemical and physiological studies of soybean β-amylase.

Abstract Soybean ( Glycine max L. Merr.) seed β-amylase has been identified among the ethanol-soluble proteins, purified and several cDNA clones isolated [Ren et al. (1993) Phytochemistry 33, 535]. Both soybean and barley ( Hordeum vulgare L.) β-amylases were soluble in ethanol solutions up to 60%. The solubility of the enzyme decreased with increasing ethanol concentration and dropped sharply between 50 and 60% ethanol. The results showed that β-amylase is an enzyme which can tolerate extensive ethanol treatment at room temperature without losing activity. In soybean seeds, β-amylase appeared to be located neither in protein bodies nor in a membrane fraction. The β-amylase accumulated in the developing seed and disappeared from the germinating cotyledons at a rate similar to that of the total seed protein. Soybean β-amylase was resistant to digestion by some proteases, such as trypsin, chymotrypsin and a protease from Staphylococcus aureus V8. Very little of the total amylase activity in soybean leaves and roots was ethanol soluble. In eight other legume seeds tested, amylase activity was very low compared to the activity present in soybean seeds.
Quantum Chemical Study of the Electron-Transfer-Catalyzed Splitting of Oxetane and Azetidine Intermediates Proposed in the Photoenzymatic Repair of (6−4) Photoproducts of DNA

Semiempirical AM1 and PM3 calculations were used to study the electron-transfer-catalyzed splitting of oxetanes and azetidines that have been proposed as intermediates in the photoenzymatic repair of the (6−4) photoproducts of dipyrimidine sites in DNA by (6−4) photolyase. The calculations show that the gas-phase splitting of an anion radical to a product complex is more exothermic than that of a cation radical, and that both are more exothermic than the neutral pathway. Low-energy pathways for splitting were found to occur by nonconcerted, two-step mechanisms for both anion and cation radical pathways, but only the anion radicals had lower rate-determining barriers for splitting than did the neutral species. In the anion radical pathway, which is thought to be followed by the enzymatic reaction, cleavage of the C5−O4‘ or C5−N4‘ bond followed by cleavage of the C6−C4‘ bond is more favorable kinetically than cleavage in the reverse order. Though the barrier for cleaving the C5−N4‘ bond first is significant...
Pion form factor in improved holographic QCD backgrounds

We extend a recent numerical calculation of the pion electromagnetic form factor ${F}_{\ensuremath{\pi}}({Q}^{2})$ in holographic QCD to study two important issues regarding the behavior of fields in the bulk. First, we show that using a chiral symmetry-breaking field formally satisfying the boundary conditions of the ``soft-wall'' model changes numerical results very little from the earlier calculation that ignores these constraints. Second, we use a background field that interpolates between ``hard-wall'' and soft-wall models to obtain an improved model that reproduces the desirable phenomenological features of both. In all cases, ${F}_{\ensuremath{\pi}}$ for large ${Q}^{2}$ is shallower than data, an effect that can be cured by relaxing the fit to one of the static observables, particularly the decay constant ${f}_{\ensuremath{\pi}}$.
Physiology and Endocrinology Symposium: maternal immunological adjustments to pregnancy and parturition in ruminants and possible implications for postpartum uterine health: is there a prepartum-postpartum nexus?

Establishment of microbial infections in the reproductive tract can have negative consequences for reproductive function of the postpartum female. Most periparturient cows experience bacterial contami- nation of the uterus after parturition, but only a fraction of these develop subclinical or clinical disease. It is not well understood why one female resolves uterine infec- tions after parturition while another develops disease. Perhaps those that develop metritis or endometritis are exposed to a greater bacterial load at parturition than those that successfully restore the uterus to a healthy condition. A second possibility is that females that develop bacterial disease have compromised immune function, either systemically or in the reproductive tract and associated lymph nodes. Here, the possibil- ity is raised that maternal immunological adjustments to the presence of the allogeneic conceptus may predis- pose some females to metritis or endometritis. Several regulatory processes ensure that adaptive immune responses against paternal antigens on the conceptus are downregulated during pregnancy. Among these are immunosuppressive effects of progesterone, local accu- mulation of immune cells that can inhibit infl ammation and T cell responses, including M2 macrophages and γδ T cells, and differentiation of regulatory T cells to inhibit alloreactive lymphocytes. Some immunologi- cal adjustments to the conceptus also make the uterus more susceptible to bacterial infection. For example, progesterone not only depresses skin graft rejection but also reduces uterine capacity to eliminate bacterial infections. Macrophages of M2 phenotype can inhibit infl ammation and facilitate persistence of some micro- bial infections. At parturition, immune defenses in the uterus may be further weakened by loss of the lumi- nal epithelium of the endometrium, which is part of the innate immune system, as well as by disappearance of intraepithelial γδ T cells that produce the antibacte- rial proteins granulysin and perforin. It is currently not known whether molecules and cells that inhibit immune responses during pregnancy persist after parturition but, if so, they could contribute to compromised immune function in the uterus. It is hypothesized that indi- vidual variation in immune adjustments to pregnancy and parturition and the reversal of these changes in the postpartum period are important determinants of sus- ceptibility of the uterus to infection.
Toward Teacher Development for the Urban in Urban Teaching

This article examines the potential of critical teacher inquiry groups to promote urban teacher retention, professional support and development. While much has been written in recent years about teacher inquiry, generally, little attention has been paid to professional development programs that highlight a critical analysis of urban schooling. Drawing on analysis of videos of group meetings, Email conversations with participants and informal interviews, this article concerns itself with a group of seven South Central Los Angeles elementary teachers that use critical inquiry to support each other in tackling multiple forms of inequality and oppression manifest in their classrooms, school and community. Brought together by a commitment to social justice, these teachers engage a set of shared readings in social and educational theory as the foundation for bi‐monthly meetings. The article concludes with recommendations for on‐going critical professional development models that support teachers as they confron...
Liver test alterations with total parenteral nutrition and nutritional status.

Liver test abnormalities are a well-recognized complication in the parenterally fed population. Numerous etiologies for the development of elevated liver tests have been suggested. However, the etiology and clinical significance remain unclear. The aim of this retrospective study was to determine the extent of liver-associated test (LAT) abnormalities in patients receiving total parenteral nutrition (TPN) and to investigate whether the composition of TPN solutions and the magnitude of malnutrition could be used to predict subsequent LAT abnormalities. Medical records of 78 adult patients who received TPN for at least 2 weeks were reviewed. All subjects had normal LAT results before TPN, were not receiving hepatotoxic drugs, and had no underlying liver disease. Aspartate aminotransferase peaked transiently during week 2 and returned to normal during week 4. Alkaline phosphatase and total bilirubin peaked during weeks 4 and 3, respectively. The average nonprotein kilocalorie distribution was approximately 80% dextrose and 20% lipid. Caloric intake ranged from 7% to 23% above estimated needs. The mean nutritional status score was 22 +/- 15, with a possible range of 0 to 75 (0 indicates no malnutrition). The composition of TPN solutions was not significantly associated with the changes in the three LATs during any week of the 4-week study. The nutritional status score was significantly associated (p less than .05) with the change in alkaline phosphatase during week 1. This study confirms that LAT abnormalities occur during TPN, but the composition of the solution has no significant ability to predict subsequent LAT abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)
New perspectives on autobiographical memory: The integration of narrative processing and autobiographical reasoning.

Researchers from diverse psychological subdisciplines have increasingly turned their attention to the storied aspect of human thought. Narrative processing and autobiographical reasoning are 2 form...
A Circadian Loop asSIRTs Itself

Daily time keeping in many organisms depends on internal circadian clocks that temporally organize biological functions relative to each other as well as the environment. These clocks generate rhythms in physiology and behavior by using circuits of gene expression that are organized in negative-feedback loops ( 1 ). Two studies in this issue, by Nakahata et al. ( 2 ) on page 654 and Ramsey et al. ( 3 ) on page [651][1], propose the addition of a new negative-feedback loop to this circuitry that involves the metabolite nicotinamide adenine dinucleotide (NAD+) and the protein SIRTUIN1 (SIRT1). The new loop suggests connections between the circadian clock and SIRT1-dependent functions associated with cell survival, development, inflammation, and metabolism. [1]: /lookup/doi/10.1126/science.1171641
Tryptophan-mediated substrate inhibition of anthranilate-5-phosphoribosylpyrophosphate phosphoribosyltransferase

Abstract A previously unrecognized type of endproduct inhibition is described. Anthranilate-5-phosphoribosylpyrophosphate phosphoribosyltransferase (PR transferase) activity from Salmonella typhimurium when aggregated to active or inactive anthranilate synthetase, is subject to endproduct-mediated substrate inhibition. Inhibition of PR transferase activity by the substrates, 5-phosphoribosyl-l-pyrophosphate (PRPP) and anthranilate, is observed in the presence of tryptophan. Substrates for the aggregated anthranilate synthetase enzyme antagonize the tryptophan-mediated substrate inhibition of PR transferase activity.
SIRTF telescope test facility: the first year

The SIRTF Telescope Test Facility (STTF) consists of an optical dewar for testing mirrors of up to 1m diameter and f < 6 at temperatures from 300K to 5K and a phase shift interferometer for optical characterization. The STTF was brought on-line in early 1995. The STTF was initially used to cool a 50cm diameter beryllium mirror that had been previously tested at NASA Ames Research Center. The initial tests validated the performance of the STTF by proving that the STTF could cool a mirror to 5K and achieve high quality optical data on the mirror, consistent with the previous results achieved at NASA Ames. The STTF has also been used to provide cryogenic optical testing of the ultra- lightweight 85cm diameter beryllium primary mirror assembly for the Infrared Telescope Technology Testbed (ITTT). Currently the facility is preparing for testing the complete ITTT. Also, the long wavelength photon background in the facility will be measured and characterized in 1996.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A Resonant Air-Standard Heat Engine

A resonant heat engine in which the piston assembly is replaced by a sealed elastic cavity is modeled and analyzed. A linearized nondimensional lumped-parameter model is derived and used to investigate the factors that control the performance of the engine. The results show that operation at resonance is beneficial. Local maxima in efficiency are encountered at odd multiples of the resonance frequency. Efficiency is enhanced by small damping.Copyright © 2010 by ASME
Kinetic parameters of phosphatase: A quantitative synthesis

Phosphatases play an important role in mineralization of organic phosphorus, soil phosphorus availability and global phosphorus cycling. Release of phosphorus in different ecosystems is important for plant growth and microbial function, and may be simulated by modeling organic phosphate mineralization. The half-saturation constant (Km) and the maximum enzyme activity (Vmax) in the Michaelis–Menten equation are the two important kinetic parameters in these models, but their values have not been systematically investigated. In this study, we compiled a database of kinetic parameters of phosphatase from 139 publications, estimated the means, variations and distributions of the kinetic parameters, and tested the differences in kinetic parameters of phosphatases of different types, origins and under different incubation conditions. We also analyzed the activation energy (Ea), temperature sensitivity (Q10), optimum pH (pHopt) and sensitivity of pH (pHsen) of phosphatase activity. Our results indicated that: 1) Both Vmax and Km were log-normal distributed with large variations; 2) There was no significant difference in Km between the acid or alkaline phosphatases, but a significantly higher Vmax for acid phosphatases was found compared with alkaline phosphatases; 3) Km and Vmax varied with the origins of enzymes and under different incubation conditions. Plant originated enzymes had the highest Vmax while soil originated enzymes had the lowest Vmax. Larger variation in Vmax was found among the incubation times than among the incubation temperatures; 4) The mean values of Ea for acid and alkaline phosphatases were 36.30 and 23.61 kJ mol−1, respectively, with an overall mean of 34.40 kJ mol−1. The mean value of estimated pHopt for acid phosphatase was 5.2 while that for alkaline phosphatase was 9.5. The information generated in this study will be useful for phosphorus mineralization modeling and uncertainty analysis.
Structures of coenzyme F420 in Mycobacterium species

The structure of coenzyme F420 in Mycobacterium smegmatis was examined using proton NMR, amino acid analysis, and HPLC. The two major F420 structures were shown to be composed of a chromophore identical to that of F420 from Methanobacterium thermoautotrophicum, with a side chain of a ribityl residue, a lactyl residue and five or six glutamate groups (F420–5 and F420–6). Peptidase treatment studies suggested that L-glutamate groups are linked by γ-glutamyl bonds in the side chain. HPLC analysis indicated that Mycobacterium tuberculosis, Mycobacterium bovis BCG, and Mycobacterium fortuitum have F420–5 and F420–6 as the predominant structures, whereas Mycobacterium avium contains F420–5, F420–6 and F420–7 in significant amounts. 7,8-Didemethyl 8-hydroxy 5-deazariboflavin (FO), an intermediate in F420 biosynthesis, accounted for about 1–7% of the total deazaflavin in cells. Peptidase treatment of F420 created F420 derivatives that may be useful for the assay of enzymes involved in F420 biosynthesis.
Cyclotron resonance of polarons in a nonparabolic band

A generalized Fr\"ohlich Hamiltonian is introduced via k\ensuremath{\cdot}p theory for the polaron problem in the InSb-type conduction band. We find that to a good approximation the polaron correction to the n=0\ensuremath{\rightarrow}n=1 cyclotron energy in the weak-coupling limit has the form \ensuremath{\alpha}S([${\mathrm{E}}_{\mathrm{\ensuremath{\uparrow}},\mathrm{\ensuremath{\downarrow}}}^{(0)}$(1)-${\mathrm{E}}_{\mathrm{\ensuremath{\uparrow}},\mathrm{\ensuremath{\downarrow}}}^{(0)}$(0)]/\ensuremath{\Elzxh}${\mathrm{\ensuremath{\omega}}}_{\mathrm{LO}}$) where ${E}_{\ensuremath{\uparrow}}$,${\mathit{\ensuremath{\downarrow}}}^{(0)}$(n) is the unperturbed nonparabolic energy of the nth Landau level (for spin up, spin down), \ensuremath{\Elzxh}${\ensuremath{\omega}}_{\mathrm{LO}}$ is the LO-phonon energy, and \ensuremath{\alpha}S(${\ensuremath{\omega}}_{c}$/${\ensuremath{\omega}}_{\mathrm{LO})}$ is the long-known weak-coupling polaron correction to the cyclotron-resonance energy in a parabolic band with unperturbed cyclotron frequency ${\ensuremath{\omega}}_{c}$. Polaron corrections to the g factor are also computed.
High throughput microscopy: from raw images to discoveries.

Technological advances in automated microscopy now allow rapid acquisition of many images without human intervention, images that can be used for large-scale screens. The main challenge in such screens is the conversion of the raw images into interpretable information and hence discoveries. This post-acquisition component of image-based screens requires computational steps to identify cells, choose the cells of interest, assess their phenotype, and identify statistically significant `hits9. Designing such an analysis pipeline requires careful consideration of the necessary hardware and software components, image analysis, statistical analysis and data presentation tools. Given the increasing availability of such hardware and software, these types of experiments have come within the reach of individual labs, heralding many interesting new ways of acquiring biological knowledge.
E-042 Case Based Review of the Pathophysiology of Internal Carotid Artery Pseudoaneurysm Coil Migration

Learning Objectives Review the pathophysiology and risk factors of internal carotid artery (ICA) pseudoaneurysm formation. Evaluate imaging of coil migration following endovascular treatment of internal carotid artery pseudoaneurysm. Discuss treatment options of coil migration. Background Pseudoaneurysm results from disruption of one or more layers of the arterial wall, which results in blood dissecting into the surrounding tissues. The formation of ICA pseudoaneurysm is a known complication related to radiation therapy and arterial injury during surgery. Endovascular coil embolisation has been proven an effective treatment for ICA pseudoaneurysm, however one of the rare complications is coil migration. Clinical Findings/Procedure Details Two patients with history of iatrogenic ICA injury during tumour resection subsequently developed pseudoaneurysms. Both were initially treated with endovascular coil embolisation and both went on to suffer migration and prolapse of the coil into the pharynx. In both cases the coil mass demonstrated migration with erosion through the pseudoaneurysm wall. The first patient underwent coil embolisation 20 years prior to presenting with globus sensation and epistaxis. The second patient, who had previously been treated with radiation, developed transmucosal coil migration 1 month after embolisation. In both cases the complications associated with coil migration were fatal. Conclusion and/or Teaching Points When treating ICA pseudoaneurysm with coil embolisation there are multiple factors which can increase the risk of coil migration. While it is rare coil migration is a known complication of endovascular embolisation which can occur months to decades after the initial procedure. Disclosures R. Morgan: None. S. Best: None. C. Connor: None. J. Madarang: None. P. Johnson: None.
Energy dissipation in shear driven turbulence.

The Navier-Stokes equations are utilized to derive upper bounds on the turbulent energy dissipation rate for an incompressible Newtonian fluid confined between parallel comoving plates. These estimates provide a rigorous foundation for one of the basic scaling ideas of turbulence theory, namely, the independence of the dissipation rate and the viscosity at high Reynolds number. The bounds are compared to experiments on turbulence in the Couette-Taylor system.
FoxM1 Regulates Growth Factor-induced Expression of Kinase-interacting Stathmin (KIS) to Promote Cell Cycle Progression

The Forkhead box M1 (FoxM1) transcription factor is essential for cell cycle progression and mitosis. FoxM1 regulates expression of Skp2 and Cks1, subunits of the SCF ubiquitin ligase complex, which ubiquitinates p27Kip1 and targets it for degradation. Kinase-interacting stathmin (KIS) is a growth factor-dependent nuclear kinase that regulates cell cycle progression by phosphorylating p27Kip1 to promote its nuclear export. Here we present an additional mechanism of FoxM1-mediated regulation of p27Kip1 and provide evidence that FoxM1 regulates growth factor-induced expression of KIS. In cells harboring FoxM1 deletion or expressing FoxM1-short interfering RNA, the expression of KIS is impaired, leading to an accumulation of p27Kip1 in the nucleus. Furthermore, we show that KIS is a direct transcriptional target of FoxM1. Thus FoxM1 promotes cell cycle progression by down-regulating p27Kip1 through multiple mechanisms.
Invited Article: The coherent optical laser beam recombination technique (COLBERT) spectrometer: Coherent multidimensional spectroscopy made easier

We have developed an efficient spectrometer capable of performing a wide variety of coherent multidimensional measurements at optical wavelengths. The two major components of the largely automated device are a spatial beam shaper which controls the beam geometry and a spatiotemporal pulse shaper which controls the temporal waveform of the femtosecond pulse in each beam. We describe how to construct, calibrate, and operate the device, and we discuss its limitations. We use the exciton states of a semiconductor nanostructure as a working example. A series of complex multidimensional spectra—displayed in amplitude and real parts—reveals increasingly intricate correlations among the excitons.
Synergistic levels of NOx emissions from soybean leaves caused by a combination of salicylic acid and photosynthetic inhibitor herbicides

Abstract Short-term experiments using soybean ( Glycine max [L.] Merr. var. “Hobbit”) leaves were conducted in the laboratory to measure the effect of salicylic acid on nitrate metabolism and to determine whether salicylic acid would act as a synergist in combination with photosynthetic inhibitor herbicides. The effects of the different treatments were measured by analysis of NO x emissions from the leaves. The NO x gases, primarily nitric oxide (NO), were formed from nitrite accumulations within the leaf caused by salicylate and herbicide treatments. Salicylate alone apparently stimulated nitrate reduction rates and caused NO x evolution in darkness but not in light. Photosynthetic inhibitor herbicides (e.g., prometryn) alone did not cause NO x evolution in light or in darkness even though nitrite reduction was inhibited. The combination of salicylic acid and prometryn produced high levels of NO x emission in either light or darkness. Salicylic acid alone and eight different photosynthetic inhibitors used alone under light, aerobic conditions did not cause NO x evolution. The combination of salicylic acid with each of these herbicides produced synergistic levels of NO x emission in every case. A diagram is presented which describes the action of salicylate causing the formation of toxic nitrate reduction intermediates within the leaf which were not present when the photosynthetic inhibitor herbicides were used alone.
The Movement of Wealth

Paper details the reasons why relationship managers move between firms, bringing with them valuable money relationships. Based upon a survey of 43 money managers, we found that the reasons for leaving are complex and that managers who change often bring the largest number of accounts but not the largest asset balances with them, as compared with managers that change infrequently. Paper studies the general problem of managing relationship managers so that they stay with the the firm rather than moving.
Functional Anatomy of the Pallidal Base in Parkinson's Disease

OBJECTIVE : The purpose of this study is to define the morphology of the boundary between the globus pallidus and the ansa lenticularis (i.e., pallidal base) in humans. This information is important for surgeons who perform pallidotomy. METHODS : Thirty-eight patients with Parkinson's disease underwent pallidotomy using microrecording techniques. The pallidal base was identified by the loss of neuronal single unit activity and by the change in background noise, as analyzed on the audio monitor and by fast Fourier transformation. RESULTS : Three quarters of the patients had an abrupt transition of the background noise from neuronal to axonal activity. One quarter of the patients had multiple successive transitions of the background activity, over a distance of 0.4 to 2 mm (median, 1 mm). CONCLUSION : We conclude that the pallidal base is not a smooth, sharp boundary between the globus pallidus and the ansa lenticularis. We propose two models that define the morphology of the pallidal base. One model depicts the pallidal base as a multifolded boundary that distinctly separates pallidal neurons from ansa lenticularis axons. Another model depicts the pallidal base as an indistinct transitional boundary between the globus pallidus and the ansa lenticularis, which contains axonal fibers intermixed with small clusters of pallidal neurons. We discuss the clinical relevance of these findings.
Electrophysiological recording in the Drosophila embryo.

Drosophila is a premier genetic model for the study of both embryonic development and functional neuroscience. Traditionally, these fields are quite isolated from each other, with largely independent histories and scientific communities. However, the interface between these usually disparate fields is the developmental programs underlying acquisition of functional electrical signaling properties and differentiation of functional chemical synapses during the final phases of neural circuit formation. This interface is a critically important area for investigation. In Drosophila, these phases of functional development occur during a period of <8 hours (at 25°C) during the last third of embryogenesis. This late developmental period was long considered intractable to investigation owing to the deposition of a tough, impermeable epidermal cuticle. A breakthrough advance was the application of water-polymerizing surgical glue that can be locally applied to the cuticle to enable controlled dissection of late-stage embryos. With a dorsal longitudinal incision, the embryo can be laid flat, exposing the ventral nerve cord and body wall musculature to experimental investigation. Whole-cell patch-clamp techniques can then be employed to record from individually-identifiable neurons and somatic muscles. These recording configurations have been used to track the appearance and maturation of ionic currents and action potential propagation in both neurons and muscles. Genetic mutants affecting these electrical properties have been characterized to reveal the molecular composition of ion channels and associated signaling complexes, and to begin exploration of the molecular mechanisms of functional differentiation. A particular focus has been the assembly of synaptic connections, both in the central nervous system and periphery. The glutamatergic neuromuscular junction (NMJ) is most accessible to a combination of optical imaging and electrophysiological recording. A glass suction electrode is used to stimulate the peripheral nerve, with excitatory junction current (EJC) recordings made in the voltage-clamped muscle. This recording configuration has been used to chart the functional differentiation of the synapse, and track the appearance and maturation of presynaptic glutamate release properties. In addition, postsynaptic properties can be assayed independently via iontophoretic or pressure application of glutamate directly to the muscle surface, to measure the appearance and maturation of the glutamate receptor fields. Thus, both pre- and postsynaptic elements can be monitored separately or in combination during embryonic synaptogenesis. This system has been heavily used to isolate and characterize genetic mutants that impair embryonic synapse formation, and thus reveal the molecular mechanisms governing the specification and differentiation of synapse connections and functional synaptic signaling properties.
Development of a database filter based on optoelectronic smart pixel arrays

We presented here the design and initial demonstration of three optoelectronic database filters. Each of these systems is intended to serve as an interface between a page oriented optical storage devices and an electronic host computer. In addition to providing optical/electrical data conversion, each filter is capable of reducing the high data rate optical input to low data rate electronic signals compatible with conventional database management systems. For each filter, the system objectives and associated design trade offs are presented. Finally, an overall trend towards increasing pixel logic complexity while reducing optical system complexity is discussed.
Flex-grid compatible ultra wide frequency comb source for 31.8 Tb/s coherent transmission of 1520 UDWDM channels

A 75 nm wide parametric frequency comb with 6.25 GHz frequency grid is used for 31.8 Tb/s coherent transmission of 1520 Nyquist UDWDM channels, offering up to 30 Gb/s per user over a 50 km of regular single mode fiber.
Metal and metalloid concentrations in the eggs of threatened Florida scrub-jays in suburban habitat from south-central Florida

Monitoring and assessing changes in contaminants in urban and suburban environments is essential to assessing ecosystem well-being in human-influenced landscapes. We analyzed metal and metalloid levels in the eggs of the threatened Florida scrub-jay (Aphelocoma coerulescens), an extremely sedentary and modestly long-lived passerine bird that is federally threatened and endemic only in Florida. Eggs that failed to hatch were collected in a suburban environment to compare with the long-term study of this species at the Archbold Biological Station, located 8 km south in a more rural part of south-central Florida. Florida scrub-jays remain in a permanent territory in scrub oak habitat where they feed mainly on insects and acorns, but in suburban habitats human-provided foods comprise 30% of their diet. From the data previously collected at Archbold, and their low position on the food chain, we expected levels of contaminants to be comparatively low and remain relatively constant over time. Except for the low mercury value, all means were within the range of mean values reported for a wide range of non-passerine species (including those at higher tropic levels), are lower than concentrations associated with abnormalities in birds, and are lower than those previously reported for scrub-jays from Archbold Biological Station. A significant increase in selenium occurred from 1996 to 2001, but did not appear associated with changes in human density.
ON QUASI-FACTORIAL DOMAINS

Abstract Basic properties of quasi-factorial domains are studied. For a locally quasi-unmixed N−1 Noetherian domain having only finitely many non-equimultiple prime ideals of height one, it is shown that these finitely many primes are associated primes of the conductor ideal. Using this result, birational integral extensions of quasi-factorial domains are studied. Some sufficient conditions are given for a quasi-factorial local domain in order that every birational integral extension of it is quasi-factorial. Descent of quasi-factoriality is studied under certain faithfully flat extensions.
A Generalization of an SPRT for the Correlation Coefficient

Abstract The sequential probability ratio tests (SPRT's) for the correlation coefficient, ρ, of a bivariate normal distribution proposed by Kowalski [3] and Pradhan and Sathe [4] reduce to SPRT's of a binomial parameter. These tests, respectively, require the sampling of one and two pairs of observations at each step of the sequential procedure. This article generalizes their SPRT's to that of sampling K (K = 1, 2, 3, …) pairs of observations at each step and compares the tests thereby generated.
Polymorphisms in IL-1β, vitamin D receptor Fok1, and Toll-like receptor 2 are associated with extrapulmonary tuberculosis

Human genetic variants may affect tuberculosis susceptibility, but the immunologic correlates of the genetic variants identified are often unclear. We conducted a pilot case-control study to identify genetic variants associated with extrapulmonary tuberculosis in patients with previously characterized immune defects: low CD4+ lymphocytes and low unstimulated cytokine production. Two genetic association approaches were used: 1) variants previously associated with tuberculosis risk; 2) single nucleotide polymorphisms (SNPs) in candidate genes involved in tuberculosis pathogenesis. Single locus association tests and multifactor dimensionality reduction (MDR) assessed main effects and multi-locus interactions. There were 24 extrapulmonary tuberculosis cases (18 black), 24 pulmonary tuberculosis controls (19 black) and 57 PPD+ controls (49 black). In approach 1, 22 SNPs and 3 microsatellites were assessed. In single locus association tests, interleukin (IL)-1β +3953 C/T was associated with extrapulmonary tuberculosis compared to PPD+ controls (P = 0.049). Among the sub-set of patients who were black, genotype frequencies of the vitamin D receptor (VDR) Fok1 A/G SNP were significantly different in extrapulmonary vs. pulmonary TB patients (P = 0.018). In MDR analysis, the toll-like receptor (TLR) 2 microsatellite had 76% prediction accuracy for extrapulmonary tuberculosis in blacks (P = 0.002). In approach 2, 613 SNPs in 26 genes were assessed. None were associated with extrapulmonary tuberculosis. In this pilot study among extrapulmonary tuberculosis patients with well-characterized immune defects, genetic variants in IL-1β, VDR Fok1, and TLR2 were associated with an increased risk of extrapulmonary disease. Additional studies of the underlying mechanism of these genetic variants are warranted.
Human frataxin activates Fe-S cluster biosynthesis by facilitating sulfur transfer chemistry.

Iron–sulfur clusters are ubiquitous protein cofactors with critical cellular functions. The mitochondrial Fe–S assembly complex, which consists of the cysteine desulfurase NFS1 and its accessory protein (ISD11), the Fe–S assembly protein (ISCU2), and frataxin (FXN), converts substrates l-cysteine, ferrous iron, and electrons into Fe–S clusters. The physiological function of FXN has received a tremendous amount of attention since the discovery that its loss is directly linked to the neurodegenerative disease Friedreich’s ataxia. Previous in vitro results revealed a role for human FXN in activating the cysteine desulfurase and Fe–S cluster biosynthesis activities of the Fe–S assembly complex. Here we present radiolabeling experiments that indicate FXN accelerates the accumulation of sulfur on ISCU2 and that the resulting persulfide species is viable in the subsequent synthesis of Fe–S clusters. Additional mutagenesis, enzyme kinetic, UV–visible, and circular dichroism spectroscopic studies suggest conserved ISCU2 residue C104 is critical for FXN activation, whereas C35, C61, and C104 are all essential for Fe–S cluster formation on the assembly complex. These results cannot be fully explained by the hypothesis that FXN functions as an iron donor for Fe–S cluster biosynthesis, and further support an allosteric regulator role for FXN. Together, these results lead to an activation model in which FXN accelerates persulfide formation on NFS1 and favors a helix-to-coil interconversion on ISCU2 that facilitates the transfer of sulfur from NFS1 to ISCU2 as an initial step in Fe–S cluster biosynthesis.
Control of phosphonic acid and phosphonolipid synthesis in Tetrahymena.

Abstract The phosphonolipid content of the protozoan Tetrahymena pyriformis was increased by growing the organism on a medium containing increasing amounts of 2-aminoethylphosphonic acid. With levels of 0, 1, 5 and 10 mM 2-aminoethylphosphonic acid, the phosphonolipid content was 23, 25, 31 and 37% of the total cellular phospholipids, respectively. This increase was accompanied by a reciprocal decrease in phosphatidylethanolamine. With 32Pi in the growth medium along with the 2-aminoethylphosphonic acid, the incorporation of the radioactivity into new molecules of 2-aminoethylphos phonic acid was almost totally inhibited, indicating a feedback control on phosphonic acid synthesis.
Rapid N2 fixation in pines? Results of a Maine field study

A recent study of the nitrogen budgets of pitch pines (Pinus rigida Mill.) and red pines (P. resinosa Ait.) growing in model ecosystems in New Hampshire (USA) reported very high nitrogen gains. Thus N2 fixation associated with the rhizosphere of pines may contribute to their success in nitrogen-limited ecosystems. We used the acetylene-reduction assay with carbon monoxide controls to determine whether high rates of N2 fixation are associated with pine forests in Maine. We measured nitrogenase activity in cores of the forest floor and the mineral soil beneath for five pitch pine, seven red pine, and six eastern white pine (P. strobus L.) stands. The stands represented 8 of the 15 biophysical regions of Maine (USA) and included a variety of age classes. We found only very low rates of nitrogenase activity, which varied seasonally with the highest values during the warmer months. The highest mean nitrogenase activity observed was 449 nmol C2H4·m−2·h−1. We estimated that <6 mg N/m2 was fixed annually by non-symbiotic diazotrophs in the soil horizons sampled. These rates are much smaller than atmospheric N inputs in Maine (300–450 mg N·m−2·yr−1) and consequently have little impact on the N budgets of the pines. Based on our results and the literature, it is likely that only low rates of N2 fixation are associated with pines.
Influence of interfacial delamination on channel cracking of elastic thin films

Channeling cracks in brittle thin films have been observed to be a key reliability issue for advanced interconnects and other integrated structures. Most theoretical studies to date have assumed no delamination at the interface, while experiments have observed channel cracks both with and without interfacial delamination. This paper analyzes the effect of interfacial delamination on the fracture condition of brittle thin films on elastic substrates. It is found that, depending on the elastic mismatch and interface toughness, a channel crack may grow with no delamination, with a stable delamination, or with unstable delamination. For a film on a relatively compliant substrate, a critical interface toughness is predicted, which separates stable and unstable delamination. For a film on a relatively stiff substrate, however, a channel crack grows with no delamination when the interface toughness is greater than a critical value, while stable delamination along with the channel crack is possible only in a small range of interface toughness for a specific elastic mismatch. An effective energy release rate for the steady-state growth of a channel crack is defined to account for the influence of interfacial delamination on both the fracture driving force and the resistance, which can be significantly higher than the energy release rate assuming no delamination.
The Cabinet Member as a Representative of the President: The Case of James Watt.

A comparison of the environmental rhetoric of former Interior Secretary Watt and President Reagan explains the political value the Cabinet member had for the President which outweighed his political liability. Cabinet members extend a President's influence by reaching issue‐specific audiences while maintaining philososphical consistency with the President and serve as surrogates on controversial issues who can keep the President free from contamination. Although subdued in official presentations, the Cabinet member's personal style will still be evident in symbolic choices, especially in addresses to partisan audiences.
Emission minimisation dispatch constrained by cost and wind power

It is important to quantitatively assess the effectiveness of reducing emissions by increasing the penetration of wind power (WP). In this study, an emission minimisation model is proposed for a sample system consisting of both thermal generators and wind turbines. In this model, the probability of stochastic WP is included in the constraint set. This approach avoids the probabilistic infeasibility caused by using the average of random variables. The proposed model is implemented and the impact of WP on emission reduction is numerically evaluated. It is found that the impact can be readily characterised by a parameter called the penetration factor of WP.
Designing microarray phantoms for hyperspectral imaging validation

The design and fabrication of custom-tailored microarrays for use as phantoms in the characterization of hyperspectral imaging systems is described. Corresponding analysis methods for biologically relevant samples are also discussed. An image-based phantom design was used to program a microarrayer robot to print prescribed mixtures of dyes onto microscope slides. The resulting arrays were imaged by a hyperspectral imaging microscope. The shape of the spots results in significant scattering signals, which can be used to test image analysis algorithms. Separation of the scattering signals allowed elucidation of individual dye spectra. In addition, spectral fitting of the absorbance spectra of complex dye mixtures was performed in order to determine local dye concentrations. Such microarray phantoms provide a robust testing platform for comparisons of hyperspectral imaging acquisition and analysis methods.
A Control-Based Approach to Accurate Nanoindentation Quantification in Broadband Nanomechanical Measurement Using Scanning Probe Microscope

This paper presents a control-based approach to accurately quantify the indentation in broadband nanomechanical property measurements using scanning probe microscope (SPM). Accurate indentation measurement is essential to probe-based material property characterization as the force exerted and the indentation generated are the two most important physical variables measured in the process. Large measurement errors, however, occur when the measurement frequency range becomes large (i.e., broadband). Such errors result from the inability of the conventional method to account for the difference between the SPM z-axis piezo actuator displacement and the vertical displacement of the cantilever at its fixed end, and the lateral-vertical coupling-caused cantilever motion when the measurement frequency range increases. A control-based approach is presented to address these limits of the conventional method. The proposed approach is demonstrated through experiments to measure the viscoelastic properties of a Polydimethylsiloxane (PDMS) sample over a broad-frequency range.
Rayleigh backscattering in optical fiber recirculating delay lines

We derive the backscattering impulse response of a recirculating fiber delay line. The response consists of periodic discontinuities that occur at multiples of the loop transit time. The magnitude of each discontinuity is found to depend only on the coupling coefficient and the number of recirculations and is independent of both propagation loss and loop length. A graphical aid for describing the response of the system is also presented.
Minor histone 2A variants and ubiquinated forms in the native H2A:H2B dimer.

Histone octamers from calf thymus were separated into (H3:H4)2 tetramers and H2A:H2B dimers by chromatography through Sephadex G100. The tetramers and dimers were analyzed for variants, ubiquitin adducts, and proteolyzed forms. The minor histone variants H2A.X and H2A.Z were found to be associated with histone H2B as H2A.X:H2B and H2A.Z:H2B dimers, respectively. Ubiquitin adducts of the H2A's and H2B were also present in H2A:H2B dimers.