cssi/SciSciGPT-SciSciNet huggingface dataset:
The Role of Dominant Rhodopsin Mutations in Drosophila Retinal Degeneration

Mutations within the human rod opsin gene are responsible for approximately 25% of the autosomal dominant forms of retinitis pigmentosa (ADRP) afflicting human populations (l).There are over 60 different mutations known in the rhodopsin gene that cause ADRP. To account for the mechanisms by which these mutations can cause retinal degeneration, three general types of models have been considered. First, improper folding mutant protein may prevent its proper maturation (2). A second model is that the mutated forms may produce rhodopsins that are constitutively active, leading to increased metabolic activity (3). A third possibility is that the mutant proteins show improper cellular localization (4). All three views are consistent with a scenario by which the dominant rhodopsin mutation reduces the health of the photoreceptor, eventually causing the cell to degenerate. Understanding the molecular basis of rhodopsin-based forms of ADRP represents a major advance, but it is likely that successful strategies for alleviating the disease will require additional knowledge on the mechanisms by which these rhodopsin mutants trigger retinal degeneration.
Diagnosis of Cirrhosis: Imaging

Liver biopsy is an essential tool for the hepatologist in the diagnosis and management of patients with cirrhosis. However, a pathological diagnosis is not always necessary to diagnose cirrhosis. Often clinical assessment with a complete history and physical examination, analysis of patterns of abnormalities in serum markers, and examination of common diagnostic radiologic modalities in totality allow for the diagnosis of cirrhosis. Abdominal imaging, namely computed tomography, ultrasound (US) with Doppler evaluation, and magnetic resonance imaging (MRI), serves as a useful crutch in this regard for both diagnostic and prognostic purposes. This chapter reviews the strengths and weaknesses of each of the modalities as it pertains to diagnosis of cirrhosis. Further, novel applications of elastography (both US and MRI-based) as another noninvasive tool to diagnose cirrhosis are discussed.
Anaerobic biosynthesis of the manganese-containing superoxide dismutase in Escherichia coli : effects of diazenedicarboxylic acid bis(N,N'-dimethylamide) (diamide)

Anaerobically grown Escherichia coli accumulate active manganese-containing superoxide dismutase (MnSOD) upon exposure to diamide. This induction requires de novo biosynthesis of MnSOD. Catalase, glutathione disulfide reductase, and glucose-6-phosphate dehydrogenase were also induced by diamide in anaerobic E. coli. A GSH-negative strain of E. coli did not produce MnSOD under anaerobic conditions and was as responsive to diamide as was the wild type strain. Diamide which had been prereduced, by incubation with GSH, was ineffective. NO3- plus paraquat, which elicits increased anaerobic biosynthesis of the MnSOD polypeptide, but not of active MnSOD, synergized with diamide in the induction of active MnSOD. A similar increase in the ability of diamide to cause anaerobic biosynthesis of active MnSOD was seen when the production of the MnSOD polypeptide was increased by isopropyl-beta-D-thiogalactopyranoside, in a strain bearing the MnSOD gene under the control of the tac promoter. These results are explained in terms of a dual action of diamide, i.e. at both the transcriptional and the maturational levels of biosynthesis of MnSOD. Oxidative inactivation of an Fe(II)-containing repressor and oxidative facilitation of insertion of manganese, in place of iron, into the nascent MnSOD polypeptide, are the postulated bases of this dual action.
Proper Orthogonal Decomposition of Pressure Field in Sloshing Impact

AbstractTo evaluate the predictive capability of the proper orthogonal decomposition (POD) in approximating dynamics of wave impact, the method is applied to the special case of sloshing problems that are widely found in engineering applications and actively pursued using numerical simulations. Because pressure is of major concern in hydrodynamic impact on structures, the POD is applied to pressure data obtained from short--duration numerical simulations of the sloshing phenomena. It is found that the number of POD modes necessary for accurate impact pressure prediction varies from ∼101 to ∼102, depending on the fill level, sloshing period, and amplitude. The POD predictions with the first few (<10) modes are sufficient for “mild” sloshing scenarios but tend to underestimate the jet-induced impact pressure at the top of the tank. It is also found that the first few modes exhibit a highly symmetric pattern. This pattern is quickly lost in the higher modes in violent sloshing scenarios, whereas it persists ...
Genetic polymorphisms in bovine ferroportin are associated with beef iron content

Iron is an essential element for almost all living organisms. Tissue iron concentration shows natural variations among individuals, because of the influence of both environmental and genetic factors. Body iron, though essential, is also toxic in excess by generating reactive oxygen species. Iron homeostasis, thus, must be maintained systemically by the rate of iron absorption, iron utilization, iron storage and the rate of iron recycling. It is possible that mutations in any of the genes that encode proteins involved in maintaining iron homeostasis have the potential to alter iron load. The effect of single nucleotide polymorphisms (SNPs), a major genetic factor, on beef iron content were investigated in the current study. The first objective of this study was to determine the variation of iron content in bovine longissimus dorsi (LD) muscle. The second objective was to identify single nucleotide polymorphisms (SNPs) in the exons and their flanking regions of the bovine ferroportin gene (Fpn) and to evaluate the association between the identified SNPs and bovine muscle iron content. LD muscle samples were collected from 1086 Angus cattle for iron quantification and genomic DNA extraction. Nine exons and their flanking regions of Fpn were amplified and sequenced with 6 selected DNA samples. Genotyping was carried out for 1086 cattle. Nine novel SNPs, NC007300: g.1780 A>G, g.1872 A>G, g.7169 C>T, g.7477 C>G, g.19208 C>T, g.19263 A>G, g.19427 A>G, g.19569 C>T and g.20480 C>T, were identified. Statistical analysis showed that three of the nine SNPs, g.19208 C>T, g.19263 A>G, and g.20480 C>T, were significantly (P < 0.007) associated
Isolation and Properties of a Testicular Ribonucleic Acid Polymerase

Abstract A procedure is described for isolation in a soluble form of a ribonucleic acid polymerase from rat testes. Evidence is presented that this enzyme catalyzes three distinct reactions: (a) deoxyribonucleic acid-directed synthesis of RNA in the presence of all four major ribonucleoside triphosphates; (b) DNA-primed formation of polyadenylic acid and other ribohomopolymers in the presence of single ribonucleoside triphosphate substrates; (c) synthesis of complementary polyribonucleotides in the presence of various ribohomopolymer primers. The properties of these reactions are discussed with respect to metal ion requirements, affinities for ribonucleoside triphosphates and primer polynucleotides, heat denaturation of DNA primers, and the effects of ionic strength, β-mercaptoethanol, polyamines, temperature, and inhibitors on the rates and extent of the reactions. The testicular ribonucleic acid polymerase is a very unstable enzyme that can be stabilized by high concentrations of glycerol.
The odds of losing at genetic roulette.

The number of harmful mutations that arise in each generation has been measured, and it is surprisingly high. This supports one theory of why evolution favours sexual reproduction, but the consequences for human health are unclear.
Porous Inorganic Materials

Porous inorganic materials cover a range of solids, both oxides and nonoxides, crystalline and amorphous, that have a pore size extending from about 3 A to over 500 A. Crystalline microporous materials such as zeolites have been known for over 200 years, and the research in the past decade has extended types of microporous materials from traditional oxides to chalcogenides and metal–organic frameworks. Efforts aimed toward developing new microporous materials that integrate uniform microporosity with other functionality have also led to promising results. Periodically ordered mesoporous materials are a recent addition to the family of ordered inorganic porous materials. They can be made in the presence of organized assemblies of organic molecules (e.g. amines, cationic, anionic, or nonionic surfactants) or polymers (e.g. amphiphilic block copolymers). Micellar solutions, lyotropic liquid crystals, and microemulsions can all serve as structure-directing agents during the cocondensation of inorganic precursors with organic species. A number of synthetic pathways have been developed for the preparation of mesoporous solids in a variety of chemical compositions including silica, organosilica, transition metal oxides, chalcogenides, and even elemental forms such as carbon and platinum. Much progress has also been made in the control of macroscopic morphologies (e.g. films, fibers, monoliths, and spheres). The pore geometry is closely related to the nature of the organic assemblies and other synthetic parameters and can be controlled to a certain degree to allow the synthesis of mesoporous materials with the desirable architecture and properties. The past decade has also witnessed a rapid development in the synthesis of ordered macroporous materials and porous materials that are ordered at multiple-length scales. Commonly used templates for the control of the macroscopic ordering include colloidal crystals such as latex or silica spheres and emulsion droplets. With the availability of a variety of inorganic porous materials, numerous applications are awaiting the exploration of materials researchers. Keywords: zeolites; molecular sieves; porous materials; microporous; mesoporous; macroporous; porous silica; porous titania; surfactants; block copolymers; liquid crystals; microemulsion
Sugar Sensing and Signaling in Plants

In addition to their essential roles as substrates in carbon and energy metabolism and in polymer biosynthesis, sugars have important hormone-like functions as primary messengers in signal transduction. The pivotal role of sugars as signaling molecules is well illustrated by the variety of sugar
China’s Foreign Trade: Perspectives From the Past 150 Years: CHINA’S FOREIGN TRADE

This paper studies the trade of China in the past 150 years, starting from the first opening of China after the Opium War. The main purpose of the paper is to identify what is (and was) China’s ‘normal’ level of foreign trade, and how these levels changed under different trade regimes, from 1840 to the present. We present new evidence on China’s foreign trade during the treaty port era (1842–1948), drawn from disaggregated trade data collected by the Chinese Maritime Customs Service, that yields important findings for current research. First, although the volume of foreign trade remained limited initially, there was a notable expansion in the diversity of products, with many new goods being imported into China. Second, the regional diffusion of foreign goods through China was greatly facilitated by the expansions of the port system. Third, the importance of Hong Kong as an intermediary in China’s trade has undergone long‐term fluctuations suggestive of learning effects. China’s recent wave of liberalization has led by the early 1990s to a trade level comparable to the high of the 1920s. While much of China’s recent growth in world trade is in line with her income growth, there is no doubt that China’s trade openness today, comparable by some measures to Denmark’s, is a stunning reversal relative to the pre‐1978 and also the pre‐1840 period. The paper emphasises the roles that history and institutional change have played in this.
In vivo measurement of rat gastric surface cell intracellular pH

Intracellular pH (pHi) of the surface mucous cells of the rat stomach was measured in vivo using a fluorescent microscopic technique. Gastric surface mucous cells were loaded with fluorescein by superfusion with 5(6)-carboxy-fluorescein diacetate, and the ratio of the intensity of emitted fluorescence at 495 and 450 nm excitation was determined by image analysis of videotapes. An in vivo calibration curve was constructed using 10(-5) M nigericin to equilibrate pHi and extracellular pH, and intra- and extracellular potassium concentrations. The pHi of the gastric surface cells was 7.22 +/- 0.06, and pHi was stable over 45 min. A pulse of 20 mM NH4Cl in Krebs solution rapidly alkalinized the cells to pH 7.7, followed by a slow return of pHi to baseline pH 7.2. After withdrawal of NH4Cl, pHi dropped to 6.7 with gradual recovery to baseline. pHi increased when the mucosa was superfused, in the presence of nigericin, with 150 mM KCl solutions and decreased when superfused with 2.6 mM KCl solutions. Perfusing with pH 3 Krebs buffers transiently decreased pHi, whereas superfusion with pH 1.2 Krebs irreversibly decreased pHi. These findings confirm that the measured fluorescence was intracellular and that the cells responded to changes in luminal pH.
Comparison of photomixotrophic and heterotrophic callus and suspension cultures of Pinus elliottii. 1. Photosynthetic properties and ultrastructural evidence for coexistence of starch granules and secondary metabolites

Photomixotrophic callus and suspension cultures of salsh pine (Pinus elliottii var. elliottii Engelm.) have been established. Callus tissues contained up to 2.76 μg chlorophyll mg-1 dry wt and suspensions 2.98 μg chlorophyll mg-1 dry wt. Maximum photosynthetic oxygen evolution was 25–32 μmol O2 h-1 mg-1 chlorophyll for callus and 35–39 μmol O2h-1 mg-1 chlorophyll for suspension, respectively. Photomixotrophic callus was friable with a high moisture content during early and exponential growth, but evolved into a compact and dense tissue during the latter stage of growth. Compact photomixotrophic callus accumulated and deposited secondary metabolites in the central vacuole and developed large starch granules in the chloroplasts. Secondary metabolites were not observed in photomixotrophic suspensions or in heterotrophic calli and suspensions. Photomixotrophic callus contained numerous mitochondria closely associated with well-developed chloroplasts containing 2–6 thylakoids per granum. Heterotrophic callus was characterized by a poorly developed cytoplasm and cup-shaped mitochondria.
IgG subclass response to immunization with Haemophilus influenzae type b polysaccharide-outer membrane protein conjugate vaccine.

ABSTRACT: We immunized 117 children with either Haemophilus influenzae type b polysaccharide vaccine or type b polysaccharide coupled to an outer membrane protein of group B Neisseria meningitidis (conjugate vaccine), and measured the IgG, IgGl, and IgG2 subclass composition of antibody to type b polysaccharide in postimmunization sera by ELISA. The IgG responses of 51 children, 24–83 months of age, immunized for the first time with the conventional type b vaccine consisted of both IgGl and IgG2 antibody (respective geometric means of 2.24 and 0.77 μg/ml). In contrast, the IgG responses of 28 infants, 2–17 months of age, immunized with conjugate vaccine were predominantly or exclusively IgGl (geometric mean IgGl and IgG2 antibody concentrations of 1.92 and 0.19 μg/ml). A total of 38 children was primed with conjugate vaccine between 2 and 17 months of age and boosted approximately 1 yr later. The 28 children boosted with type b polysaccharide vaccine showed memory antibody responses consisting of both IgGl and IgG2 (respective geometric means of 12.7 and 4.8 μg/ml); the 10 children boosted with conjugate vaccine showed a similar pattern of IgG subclass responses (respective geometric means of 20.8 and 5.1 μg/ml, p > 0.4 compared to the respective geometric mean IgGl and IgG2 values of the group boosted with polysaccharide). Thus, in children 24–83 months of age, immunization with conventional type b polysaccharide vaccine generally elicits both IgGl and IgG2 responses, with a slight predominance of IgGl. In contrast, in infants 2–17 months of age, immunization with conjugate vaccine evokes a restricted IgGl antibody response to the polysaccharide but primes for both IgGl and IgG2 responses to a booster immunization with conventional polysaccharide or conjugate vaccine.
A general approach to moment calculation for polygons and line segments

Abstract The calculation of moments from the boundary of a solid digital area is a quite useful technique used in pattern recognition. A straightforward way of doing the calculation that does not have any numerical instabilities is presented. All the symmetries available in moment calculations are preserved, and it is shown how different moment formulas are related to each other. This includes relations between different moments and the relationships among different methods for calculating moments. Finally a direct relation between the moment expansion of a polygonal area and a stick figure made from one-dimensional lines embedded in a two-dimensional plane is derived.
SU(3) for constituent and current quarks: how different are they.

Algebraic properties of thr transformation between constituent- and current-quark bases are discussed in the case when SU(3) is broken for the current quarks. In a simple model, it is shown that SU(4)w may still be an exact symmetry in the constituent-quark basis. Still within the context of the model, the question of whether the transformation actually does distinguish two SU(3) algebras in nature, one for current and one for constituent quarks, is investigated. It is shown that the so-called sigma terms of meson-baryon scattering provide a means of determiming if there is such a distinction. (auth)
RESULTS OF A PROSPECTIVE PROTOCOL OF COMPUTED TOMOGRAPHIC ANGIOGRAPHY IN PLACE OF CATHETER ANGIOGRAPHY AS THE ONLY DIAGNOSTIC AND PRETREATMENT PLANNING STUDY FOR CEREBRAL ANEURYSMS BY A COMBINED NEUROVASCULAR TEAM

Objective At many centers, patients undergo both computed tomographic angiography (CTA) and digital subtraction angiography (DSA). This practice negates most of the advantages of CTA, and it renders the risks and disadvantages of the two techniques additive. Previous reports in the literature have assessed the sensitivity and specificity of CTA compared with DSA; however, these investigations have not analyzed the clinical implications of a protocol that replaces DSA with CTA as the only diagnostic and pretreatment planning study for patients with cerebral aneurysms. Methods Since late 2001/early 2002, the combined neurovascular unit of the Massachusetts General Hospital has adopted a prospective protocol of CTA in place of DSA as the only diagnostic and pretreatment planning study for patients with cerebral aneurysms (ruptured and unruptured). We report the results obtained during the 12-month period from January 2002 to January 2003. Results During the study period, 223 patients with cerebral aneurysms underwent initial diagnostic evaluation for cerebral aneurysm by the combined neurovascular team of Massachusetts General Hospital. Of the 223 patients, 109 patients had confirmed subarachnoid hemorrhage (Group A) and 114 patients did not have SAH (Group B). All of these patients were included in the prospective CTA protocol. Cerebral aneurysm treatment was initiated on the basis of CTA alone in 93 Group A patients (86%), in 89 Group B patients (78%), and in 182 patients (82%) overall. Treatment consisted of surgical clipping in 152 patients (68%), endovascular coiling in 56 patients (25%), endovascular parent artery balloon occlusion in 4 patients (2%), and external carotid artery to internal carotid artery bypass and carotid artery surgical occlusion in 2 patients (1%). Nine patients (4%) did not undergo treatment. The cerebral aneurysm detection rate by CTA was 100% for the presenting aneurysm (ruptured aneurysm in Group A or symptomatic/presenting aneurysm in Group B) in both groups. The detection rate by CTA for total cerebral aneurysms, including incidental multiple aneurysms, was 95.3% in Group A, 98.3% in Group B, and 97% overall. The overall morbidity associated with DSA (pretreatment or as intraoperative or postoperative clip evaluation) was one patient (1.3%) with a minor nonneurological complication, one patient (1.3%) with a minor neurological complication, and no patients (0%) with a major neurological complication. Conclusion We have demonstrated promising results with a prospective protocol of CTA in place of DSA as the only diagnostic and pretreatment planning study for patients with ruptured and unruptured cerebral aneurysms. It seems safe and effective to make decisions regarding treatment on the basis of CTA, without performing DSA, in the majority of patients with ruptured and unruptured cerebral aneurysms.
Human Echo Perception

It has been shown that human test subjects have the ability, under controlled laboratory conditions, to use echoes to detect the presence or absence of targets placed before them. In addition, blind and sighted persons have been able to detect a target monaurally, to make simple shape discriminations, and to locate a target in space. Signal, environmental, and individual variability affect performance in a measurable fashion. This research is an initial step in measuring the limits of a human being9s ability to use echoes as a source of information about his physical surroundings. At this point it seems unlikely that the unaided human ear can rival the bat9s auditory system for echo perception. It may be, however, that modern technology can partially bridge the evolutionary gap and bring more useful echoes to man9s ear than those it now receives. Such an accomplishment would allow us to examine the extent to which man might benefit from this means of sensing his environment.
The impact of top performers on project teams

Management and scholars have been searching for the determinants of project team performance for many years. Individual characteristics and intra‐team processes are most often hypothesized to influence team performance. To date, though, we still do not really understand why some teams perform better than other teams. Studies have provided mixed findings and inconclusive results. The study described in this article continues the search for variables that influence project team performance. The findings provide support for an increasingly, albeit controversial, discussion occurring within human resource circles, concerning the impact of top performers on team performance.
Novel Class Detection and Feature via a Tiered Ensemble Approach for Stream Mining

Static data mining assumptions with regard to features and labels often fail the streaming context. Features evolve, concepts drift, and novel classes are introduced. Therefore, any classification algorithm that intends to operate on streaming data must have mechanisms to mitigate the obsolescence of classifiers trained early in the stream. This is typically accomplished by either continually updating a monolithic model, or incrementally updating an ensemble. Traditional static data mining algorithms futile in a streaming context (and often in a distributed sensor network) due to their need to iterate over the entire data set locally. Our approach -- named HSMiner (Hierarchical Stream Miner) -- takes a hierarchical decomposition approach to the ensemble classifier concept. By breaking the classification problem into tiers, we can better prune the irrelevant features and counter individual classification error through weighted voting and boosting. In addition, the atomic decomposition of feature inputs enables straightforward mapping to distributing the ensemble among resources in the network. The implementation proves to be fast and very memory conservative, and we emulate a distributed environment via signal-linked threads. We examine the theoretical and empirical analysis of our approach, specifically examining trade-offs of three different novel class detection variations, and compare these results to a similar method using benchmark data sets.
Spin stability of dual-spin spacecrafts.

The spin-axis attitude stability in torque-free environment of dual-spin spacecrafts with energy losses in both bodies is studied by analytical means. A new mathematical model, which assumes the high speed rotor to be symmetrical, is introduced and analyzed. The linearized variational system of equations for the model with periodic coefficients is transformed to a kinematically similar autonomous system (according to Floquet and Liapunov) which can be analyzed routinely using established procedure. As an example, this technique is used on a recent mathematical model of the SAS-A spacecraft to establish steady state stability over a wide range of speeds.
Release of propranolol HCl from a tablet coated with a macroporous membrane

Abstract The release of propranolol HCl from core tablets coated by compression with ethyl cellulose (EC) or cellulose acetate butyrate (CAB 381 or CAB 500) was studied. The release profile was typically sigmoidal, with a constant release segment. The zero-order release rate constant (k0) for EC was 6.63 ± 0.45 mg/h compared to 1.98 ± 0.16 mg/h for CAB 381 and 2.56 ± 0.27 mg/h for CAB 500. The media transfer coefficient into the EC disks also was much faster (64.50 ± 4.94 × 10−5 cm2/h) than that for CAB 381 (7.57 ± 0.39 × 10−5 cm2/h) or CAB 500 (8.09 ± 1.31 × 10−5 cm2/h). The propranolol HCl dissolution rate constant at 25 rpm was not significantly affected by the pressure used to make the core tablet (p = 0.712). The decline in K0 with increasing amounts of polymer used in the coat was accurately modelled by an exponential function (r2 = 0.971). The extrapolated value for the intrinsic dissolution rate with no polymer coating (206.10 mg/cm2 per h) was close to the determined intrinsic dissolution rate (210.47 mg/cm2 per h). Increasing the compression pressure resulted in an initial decline in the normalized mass transfer coefficient, Kn, followed by an increase in Kn; the influence of pressure on Kn diminished with increasing polymer amount. Since Kn incorporates the reduction in coat thickness and the radial expansion of the core tablet (due to the applied pressure), the increase in Kn is probably due to microscopic stress fractures in the coat.
New tight-binding parameters for covalent solids obtained using Louie peripheral states

Excited $s$ states are added to the minimal-basis tight-binding theory of covalent solids using Louie's perturbation approach. This brings the conduction bands into better accord with experiment without appreciably complicating the calculation of properties in the bond-orbital approximation. Universal interatomic matrix elements are obtained by fitting the free-electron bands, and then adjusted to accord with the bands of germanium. Bands based upon these interatomic matrix elements, and upon Hartree-Fock term values, are then compared with pseudopotential bands for Si, Ge, Sn, GaAs, InSb, ZnSe, and CdTe. A single set of metallic, covalent, and polar energies for $s{p}^{3}$ hybrids obtained from the new matrix elements are found to predict good values for both the dielectric and elastic properties; in contrast, two different sets were required for the two classes of properties in the earlier theory.
Hydrodynamic Transport of Drifting Macroalgae Through a Tidal Cut

Drifting macroalgae are unattached seaweeds that are commonly found in many South Florida and Gulf of Mexico shallow-water seagrass habitats. They are primarily comprised of species of red algae (Rhodophyta) and some brown algae (Phaeophyta). Because of the unattached nature of these species, drift algae have the ability to be moved around the landscape primarily by tidal, as well as wind-driven and alongshore currents. Numerous invertebrates and some fish species are typically found associated with drift algal clumps and aggregations. Transport of drift algae is an important dispersal mechanism for both the plants and their associated fauna. Dispersal distances have been studied in numerous locations over a range of spatial scales. However, little is known about quantities of algal material that are involved. In this study I report on composition and biomass of drifting algae that are transported through a tidal inlet in Biscayne Bay, Florida. Sargassum (a brown alga) and about 12 genera of red algae were found in three seasonal collections (Aug., Dec., May). Total biomass collected varied among seasons, with larger average amounts of drift algae collected in May than the other two months sampled. From this data, I calculate the approximate quantities of drift algae that are potentially moving in, or out of, Biscayne Bay, about a half to one ton of biomass per day.
Chemoenzymatic Synthesis and Fcγ Receptor Binding of Homogeneous Glycoforms of Antibody Fc Domain. Presence of a Bisecting Sugar Moiety Enhances the Affinity of Fc to FcγIIIa Receptor

Structurally well-defined IgG-Fc glycoforms are highly demanded for understanding the effects of glycosylation on an antibody’s effector functions. We report in this paper chemoenzymatic synthesis and Fcγ receptor binding of an array of homogeneous IgG-Fc glycoforms. The chemoenzymatic approach consists of the chemical synthesis of defined N-glycan oxazolines as donor substrates, the expression of the Fc domain in a CHO cell line in the presence of an α-mannosidase inhibitor kifunensine, and an endoglycosidase-catalyzed glycosylation of the deglycosylated Fc domain (GlcNAc-Fc homodimer) with the synthetic glycan oxazolines. The enzyme from Arthrobacter protophormiae (Endo-A) was found to be remarkably efficient to take various modified N-glycan core oxazolines, including the bisecting sugar-containing derivatives, for Fc glycosylation remodeling, resulting in the formation of the corresponding homogeneous Fc glycoforms. Nevertheless, neither Endo-A nor the Mucor hiemalis endoglycosidase mutants (EndoM-N17...
Modelling cholera in periodic environments

We propose a deterministic compartmental model for cholera dynamics in periodic environments. The model incorporates seasonal variation into a general formulation for the incidence (or, force of infection) and the pathogen concentration. The basic reproduction number of the periodic model is derived, based on which a careful analysis is conducted on the epidemic and endemic dynamics of cholera. Several specific examples are presented to demonstrate this general model, and numerical simulation results are used to validate the analytical prediction.
Cardinal functions for $k$-spaces

JAMES R. BOONE, SHELDON W. DAVIS AND GARY GRUENHAGEAbstract. In this paper, four cardinal functions are defined on the class offc-spaces. Some of the relationships between these cardinal functions arestudied. Characterizations of various ?-spaces are presented in terms of theexistence of these cardinal functions. A bound for the ordinal invariant k ofArhangelskii and Franklin is established in terms of the tightness of thespace. Examples are presented which exhibit the interaction between thesecardinal invariants and the ordinal invariants of Arhangelskii and Franklin.
Longitudinal effects of pregnancy on the pharmacokinetics of theophylline

The effects of pregnancy on the disposition of theophylline were assessed in 10 patients throughout pregnancy and post-partum. The clearance relative to total theophylline concentrations was only slightly affected during the first two trimesters (2.61 +/- 0.63 l/h and 2.85 +/- 1.05 l/h), while a statistically significant reduction was evident late in pregnancy (2.05 +/- 0.49 l/h). Post-partum clearance values (2.16 +/- 2.81 l/h) suggest an ongoing suppression relative to pre-pregnancy levels. A similar pattern was evident with clearance values based on free theophylline plasma concentrations (p = 0.12). Absolute volume of distribution increased in concert with gestation, suggesting that theophylline partitions into the enlarged tissue spaces. In addition, theophylline binding to plasma proteins decreased, albeit insignificantly, during the second (fraction bound = 29%) and third (32%) trimesters compared to post-partum values (41%). Increases in half-life during the third trimester (13.00 +/- 2.31 h vs 9.53 +/- 3.53 h post-partum) were highly significant. This change reflects the net effect of reduced clearance and increased distribution. Breast feeding had no effect on the disposition of theophylline, although the transfer of this compound into breast milk was confirmed.
A rapid FTIR method for screening methyl sulfide and hexanal in modified atmosphere meal, ready-to-eat entrees

Abstract Two of the major degradation products in thermally processed meal, ready-to-eat (MRE) products are hexanal and methyl sulfide. A rapid and reliable Fourier Transform infrared (FTIR) spectroscopic method was developed to screen hexanal and methyl sulfide levels in retorted MRE products. The S–CH 3 group of methyl sulfide and C=O of hexanal showed characteristic bending vibrations at 1317 and 1745 cm −1 , respectively. Performing a comparative gas chromatography analysis validated the FTIR method. The method was then applied to determine changes in the levels of hexanal and methyl sulfide in four MRE products packed under air and three modified atmosphere headspaces and stored under ambient and elevated temperatures. The increase in methyl sulfide level with time and temperature was statistically significant ( P
ON THE SIZE DEPENDENCE OF THE INCLINATION DISTRIBUTION OF THE MAIN KUIPER BELT

We present a new analysis of the currently available orbital elements for the known Kuiper belt objects. In the nonresonant, main Kuiper belt, we find a statistically significant relationship between an object's absolute magnitude (H) and its inclination (i). Objects with H 6.5 (radii 170 km). We have shown that this relationship is not caused by any obvious observational bias. We argue that the main Kuiper belt consists of the superposition of two distinct distributions. One is dynamically hot, with inclinations as large as ~35° and absolute magnitudes as bright as 4.5; the other is dynamically cold, with i 5° and H > 6.5. The dynamically cold population is most likely dynamically primordial. We speculate on the potential causes of this relationship.
Presence of the same types of nonhistone chromosomal proteins in different tissues.

Die Analyse mit Polyacrylamide-Gel-Electrophorese von Chromatinproteinen an Huhner-Embryonen, Ratten Ascites Hepatoma, Rattenleber und verschiedenen Teilen des Rattengehirns hat ergeben, dass dieselben Hauptfraktionen der sauren Chromosomenproteine in allen untersuchten Geweben vorhanden sind.
Slot-based formulation for the short-term scheduling of multistage, multiproduct batch plants with sequence-dependent changeovers

In this paper, we address the short-term scheduling of multiproduct batch plants with parallel identical/nonidentical reactors, a challenging problem that has been motivated by a real-world applica...
Fiber-optic Cherenkov radiation excited by few-cycle pulses

Fiber-optic Cherenkov radiation has emerged as a wavelength conversion technique to achieve isolated spectrum in the visible wavelength range. Most published results have reinforced the impression that CR forms a narrowband spectrum with poor efficiency. We both theoretically and experimentally investigate fiber-optic Cherenkov radiation excited by few-cycle pulses. We introduce the coherence length to quantify the Cherenkov-radiation bandwidth and its dependence on propagation distance. Detailed numerical simulations verified by experimental results reveal three unique features that are absent when pumped with often-used, long pulses; that is, continuum generation (may span one octave in connection with the pump spectrum), high conversion efficiency (up to 40%), and broad bandwidth (70 nm experimentally obtained) for the isolated Cherenkov radiation spectrum. These merits allow achieving broadband visible-wavelength spectra from low-energy ultrafast sources which opens up new applications.
Analysis of coastal protection under rising flood risk

Infrastructure located along the U.S. Atlantic and Gulf coasts is exposed to rising risk of flooding from sea level rise, increasing storm surge, and subsidence. In these circumstances coastal management commonly based on 100-year flood maps assuming current climatology is no longer adequate. A dynamic programming cost–benefit analysis is applied to the adaptation decision, illustrated by application to an energy facility in Galveston Bay. Projections of several global climate models provide inputs to estimates of the change in hurricane and storm surge activity as well as the increase in sea level. The projected rise in physical flood risk is combined with estimates of flood damage and protection costs in an analysis of the multi-period nature of adaptation choice. The result is a planning method, using dynamic programming, which is appropriate for investment and abandonment decisions under rising coastal risk.
Comparison of virtual fluoroscopy to conventional fluoroscopy for C1–C2 transarticular screw fixation

Purpose of study: To compare virtual fluoroscopy to conventional fluoroscopy for transarticular screw fixation in a cadaveric model. Methods used: Twenty-two C1–C2 transarticular screws were placed in 11 cadavers using either virtual fluoroscopy or conventional fluoroscopy. One side of each cadaver was treated using virtual fluoroscopy, and the other side was treated using conventional fluoroscopy; the order of techniques was alternated between consecutive cadavers. Procedure time and fluoroscopy time were recorded. After the procedure, the spines were harvested and analyzed to determine the accuracy of screw placement and length using a standard technique. Measurement of anatomic vertebral parameters was also performed allowing new recommendations for safe screw placement. of findings: Significantly less fluoroscopy time (p=.046) was required in the virtual fluoroscopy group (3.2 vs. 5.7 seconds), although the fluoroscopy time was small in both groups. No significant differences (p<.05) in procedure time were found. In the conventional fluoroscopy group, two screws were found to be partially malpositioned without endangering vital or neurovascular structures. In the virtual fluoroscopy group, there were five malpositioned screws with one screw demonstrating contact with the vertebral artery. Three of the 11 cadavers were found to have unsatisfactory anatomy for C1–C2 screw placement in that the bony corridor for screw placement was small than the diameter of the screw. Relationship between findings and existing knowledge: Virtual fluoroscopy is gaining acceptance in many areas of musculoskeletal surgery. However, there are no reports of the use of virtual fluoroscopy to guide the placement of C1–C2 transarticular screws. Overall significance of findings: Although C1–C2 transarticular screws are known to provide rigid fixation of the atlantoaxial complex, the operative setup and surgical technique remain a challenge. Traditionally, a combination of anatomic and fluoroscopy landmarks are used to guide implant placement. Virtual fluoroscopy has the potential to simplify the setup and procedure, but screw accuracy remains a concern. The results of this study suggest virtual fluoroscopy may lead to decreased accuracy, and therefore further refinement of the technique should be undertaken before it can be recommended for clinical applications. Disclosures: Device or drug: screw. Status: not approved. Conflict of interest: No conflicts.
Onset of the molecular quasicontinuum in SF6

Abstract We present a new model of V-V relaxation in SF 6 based upon an actual expansion of the molecular potential energy surface. The model predicts both a strict upper bound on the number of vibrational levels coupled at any given level and an onset of the molecular quasicontinuum at 8 v 3 .
Impact of expanding syringe access in New York on sources of syringes for injection drug users in Harlem and the Bronx, NYC, USA

Abstract Beginning in January 2001, it became legal for pharmacies, health care facilities and certain health care providers in New York State (NYS) to sell or provide syringes (10 maximum) without prescription. Cross-sectional survey data from three research projects recruiting active injection drug users (IDUs) in Harlem and the South Bronx ( n =682) were analysed by calendar quarter, from January 2001 through September 2002, to assist in an evaluation of the impact of the program, the Expanded Syringe Access Demonstration Program (ESAP). The outcome variable examined was having used a pharmacy as the source of the last injection syringe. The percent of IDUs who knew that it was legal to buy a syringe from a pharmacy increased over time (25–54%, P
Spatial and Temporal Changes in the Offshore Larval Fish Assemblage in Southeastern Lake Michigan

The larval fish assemblage in southeastern Lake Michigan was sampled monthly (May to September 1983) between 1.7 and 23.9 km offshore. Larval densities were calculated for the neuston, epilimnion, metalimnion, and hypolimnion strata of the water column. Larval densities were generally less than 0.4 m−3 with the exception of bloater (Coregonus hoyi) which reached 15 m−3 in the offshore neuston in August. The abundance of larvae was estimated for a 1-km-wide (N–S) by 26.2-km-long (E–W) strip of the lake and discussed with respect to inshore (0.7–7.1 km), intermediate (7.1–11.1 km), and offshore (11.1–26.9 km) zones. The inshore was dominated by larval rainbow smelt (Osmerus mordax) and alewife (Alosa pseudoharengus), and the offshore zone was dominated by bloater and deepwater sculpin (Myoxocephalus thompsoni). The changes in abundance and distribution of larvae reflected differences in spawning and hatching seasons and behavior of the different species. Species richness (number of species) increased and subsequently decreased in a progression from inshore to offshore. Maximum species richess occurred in June and July. Abundance was always higher in offshore waters. Maximum larval abundance occurred early in the season (June) and declined steadily through to September. Deepwater sculpin was the most abundant larval species in the areas sampled. Together, deepwater sculpin and bloater constituted 70–99% of the total abundance of larvae. In general, there was little overlap in the distributions of the various species over temporal and depth scales. Bloater and deepwater sculpin were separated from each other by their depth distributions; alewives were separated temporally from all other species.
Supramolecular Allosteric Cofacial Porphyrin Complexes

Nature routinely uses cooperative interactions to regulate cellular activity. For years, chemists have designed synthetic systems that aim toward harnessing the reactivity common to natural biological systems. By learning how to control these interactions in situ, one begins to allow for the preparation of man-made biomimetic systems that can efficiently mimic the interactions found in Nature. To this end, we have designed a synthetic protocol for the preparation of flexible metal-directed supramolecular cofacial porphyrin complexes which are readily obtained in greater than 90% yield through the use of new hemilabile porphyrin ligands with bifunctional ether-phosphine or thioether-phosphine substituents at the 5 and 15 positions on the porphyrin ring. The resulting architectures contain two hemilabile ligand-metal domains (RhI or CuI sites) and two cofacially aligned porphyrins (ZnII sites), offering orthogonal functionalities and allowing these multimetallic complexes to exist in two states, "condensed" or "open". Combining the ether-phosphine ligand with the appropriate RhI or CuI transition-metal precursors results in "open" macrocyclic products. In contrast, reacting the thioether-phosphine ligand with RhI or CuI precursors yields condensed structures that can be converted into their "open" macrocyclic forms via introduction of additional ancillary ligands. The change in cavity size that occurs allows these structures to function as allosteric catalysts for the acyl transfer reaction between X-pyridylcarbinol (where X = 2, 3, or 4) and 1-acetylimidazole. For 3- and 4-pyridylcarbinol, the "open" macrocycle accelerates the acyl transfer reaction more than the condensed analogue and significantly more than the porphyrin monomer. In contrast, an allosteric effect was not observed for 2-pyridylcarbinol, which is expected to be a weaker binder and is unfavorably constrained inside the macrocyclic cavity.
Modulations in Respiratory and Laryngeal Activity Associated With Changes in Vocal Intensity During Speech

We tested the hypothesis that different strategies are used to alter tracheal pressure (Pt) during sustained and transient increases in intensity. It has been suggested that the respiratory system ...
A branch and bound algorithm for the maximum clique problem

Abstract A method to solve the maximum clique problem based on an unconstrained quadratic zero-one programming formulation is presented. A branch and bound algorithm for unconstrained quadratic zero-one programming is given that uses a technique to dynamically select variables for the ordering of the branching tree. Dynamic variable selection is equivalent to vertex selection in a similar branch and bound algorithm for the maximum clique problem. In this paper we compare two different rules for selecting a vertex. The first rule selects a variable corresponding to a vertex with high connectivity (a greedy approach) and the second rule selects a variable corresponding to a vertex with low connectivity (a nongreedy approach). We demonstrate that the first rule discovers a maximum clique sooner but it takes significantly longer to verify optimality. Computational results for an efficient vectorizable implementation on an IBM 3090 are provided for randomly generated graphs with up to 1000 vertices and 150,000 edges.
Enhanced abdominal aortic aneurysm (AAA) formation in timp-1-deficient (timp-1-/-) mice after local elastase perfusion

Abstract Background: Matrix metalloproteinases (MMPs) are known elastolytic mediators of abdominal aortic aneurysm (AAA) degeneration, and their activity is tightly regulated by the presence of tissue inhibitors of MMPs (TIMPs). TIMPs act as a negative regulator of MMPs. Imbalances in this system may be instrumental in compromising arterial wall integrity. The aim of this study is to show that, in an elastase-induced murine model of aneurysm formation, TIMP-1 has a protective effect. Methods: 24 wild-type (TIMP-1 +/+ ) and 22 knockout (TIMP-1 −/− ) mice underwent laparotomy and isolation of the infrarenal aorta. A polyethylene catheter was inserted into the aorta and dilute pancreatic elastase (0.39 Units/ml) was infused over 5 minutes using a perfusion pump. Pre- and postperfusion maximal aortic diameters were obtained in triplicate for each animal using NIH Image. Final aortic measurements were obtained 14 days later, prior to perfusion fixation with 10% buffered-formalin. Aortic specimens were sectioned and stained with Verhoeff-van Giessen and HE data are presented as mean ± SEM. Results: Mean aortic diameter change was not significantly different between groups immediately following perfusion: 84 ± 4% (TIMP-1 +/+ ) vs. 92 ± 5% (TIMP-1 −/− ). However, 14 days later, TIMP-1 −/− mice showed a two-fold increase in maximal aortic diameter relative to postperfusion measurements, as compared to TIMP-1 +/+ mice (108 ± 13% vs. 54 ± 9%, p = 0.001). A significant difference in mean aortic diameter between TIMP-1 +/+ and TIMP-1 −/− mice was also observed when comparing size change from preperfusion to time of sacrifice (p = 0.001). Histologically, TIMP-1 −/− mice had a pronounced inflammatory infiltrate and extensive elastin fragmentation, whereas TIMP-1 +/+ mice maintained an intact elastic lamellar structure and absence of inflammatory cells. Conclusions: TIMP-1 −/− mice developed significantly larger aneurysms compared to TIMP-1 +/+ mice. This study demonstrates the protective effects of TIMP-1 by inhibiting the effects of MMPs in an experimental AAA model and may provide a means for pharmacologically controlling the progressive growth in aneurysms.