cssi/SciSciGPT-SciSciNet huggingface dataset:
Tracking and Object Classification for Automated Surveillance

In this paper we discuss the issues that need to be resolved before fully automated outdoor surveillance systems can be developed, and present solutions to some of these problems. Any outdoor surveillance system must be able to track objects moving in its field of view, classify these objects and detect some of their activities. We have developed a method to track and classify these objects in realistic scenarios. Object tracking in a single camera is performed using background subtraction, followed by region correspondence. This takes into account multiple cues including velocities, sizes and distances of bounding boxes. Objects can be classified based on the type of their motion. This property may be used to label objects as a single person, vehicle or group of persons. Our proposed method to classify objects is based upon detecting recurrent motion for each tracked object. We develop a specific feature vector called a 'Recurrent Motion Image' (RMI) to calculate repeated motion of objects. Different types of objects yield very different RMI's and therefore can easily be classified into different categories on the basis of their RMI. The proposed approach is very efficient both in terms of computational and space criteria. RMI's are further used to detect carried objects. We present results on a large number of real world sequences including the PETS 2001 sequences. Our surveillance system works in real time at approximately 15Hz for 320?240 resolution color images on a 1.7 GHz pentium-4 PC.
Development of a bioartificial liver employing xenogeneic hepatocytes

Liver failure is a major cause of mortality. A bioartificial liver (BAL) employing isolated hepatocytes can potentially provide temporary support for liver failure patients. We have developed a bioartificial liver by entrapping hepatocytes in collagen loaded in the luminal side of a hollow fiber bioreactor. In the first phase of development, liver-specific metabolic activities of biosynthesis, biotransformation and conjugation were demonstrated. Subsequently anhepatic rabbits were used to show that rat hepatocytes continued to function after the BAL was linked to the test animal. For scale-up studies, a canine liver failure model was developed using D-galactosamine overdose. In order to secure a sufficient number of hepatocytes for large animal treatment, a collagenase perfusion protocol was established for harvesting porcine hepatocytes at high yield and viability. An instrumented bioreactor system, which included dissolved oxygen measurement, pH control, flow rate control, an oxygenator and two hollow fiber bioreactors in series, was used for these studies. An improved survival of dogs treated with the BAL was shown over the controls. In anticipated clinical applications, it is desirable to have the liver-specific activities in the BAL as high as possible. To that end, the possibility of employing hepatocyte spheroids was explored. These self-assembled spheroids formed from monolayer culture exhibited higher liver-specific functions and remained viable longer than hepatocytes in a monolayer. To ease the surface requirement for large-scale preparation of hepatocyte spheroids, we succeeded in inducing spheroid formation in stirred tank bioreactors for both rat and porcine hepatocytes. These spheroids formed in stirred tanks were shown to be morphologically and functionally indistinguishable from those formed from a monolayer. Collagen entrapment of these spheroids resulted in sustaining their liver-specific functions at higher levels even longer than those of spheroids maintained in suspension. For use in the BAL, a mixture of spheroids and dispersed hepatocytes was used to ensure a proper degree of collagen gel contraction. This mixture of spheroids and dispersed cells entrapped in the BAL was shown to sustain the high level of liver-specific functions. The possibility of employing such a BAL for improved clinical performance warrants further investigations.
Design and Fabrication of Large CCDs for the Keck Observatory Deimos Spectrograph

The Keck II Deep Imaging Multi-Object Spectrograph (DEIMOS) is a general purpose, faint object, multi-slit, double-beam spectrograph which offers wide spectral coverage, high spectral resolution, high throughput, and long slit length on the sky. This powerful instrument will be the principal optical spectrograph on the Keck II telescope. DEIMOS is optimized for faint-object spectroscopy of individual point sources, low-surface-brightness extended objects, or widely distributed samples of faint objects on the sky. To obtain high resolution (∼1 A) and wide spectral coverage (up to 5000 A) the spectrograph uses wide angle cameras and large CCD detectors with many pixels.
Repression of Drosophila Photoreceptor Cell Fate through Cooperative Action of Two Transcriptional Repressors Yan and Tramtrack

The Drosophila yan gene encodes an E twenty-six (ETS) domain nuclear protein with a transcription repressor activity that can be downregulated through phosphorylation by mitogen-activated protein kinase (MAPK). Before photoreceptor precursor cells commit to a particular cell fate, Yan is required to maintain them in an undifferentiated state. We report here identification of tramtrack (ttk) mutations that act as dominant enhancers of yan. We show that ttk synergistically interacts with yan to inhibit the R7 photoreceptor cell fate. Since ttk products are nuclear proteins with zinc-finger DNA-binding motifs, yan and ttk represent two nuclear regulators essential for the control of cellular competence for neural differentiation. Reduction of either yan or ttk activity suppresses eye phenotypes of the kinase suppressor of ras (ksr) gene mutation, which is consistent with the involvement of yan and ttk in the Ras/MAPK pathway.
Simple Experimental Methods for Determining the Apparent Focal Shift in a Microscope System

Three-dimensional optical microscopy is often complicated by a refractive index mismatch between the sample and objective lens. This mismatch causes focal shift, a difference between sample motion and focal-plane motion, that hinders the accuracy of 3D reconstructions. We present two methods for measuring focal shift using fluorescent beads of different sizes and ring-stained fluorescent beads. These simple methods are applicable to most situations, including total internal reflection objectives and samples very close to the interface. For distances 0–1.5 μm into an aqueous environment, our 1.49-NA objective has a relative focal shift of 0.57 ± 0.02, significantly smaller than the simple n2/n1 approximation of 0.88. We also expand on a previous sub-critical angle theory by means of a simple polynomial extrapolation. We test the validity of this extrapolation by measuring the apparent focal shift in samples where the refractive index is between 1.33 and 1.45 and with objectives with numerical apertures between 1.25 and 1.49.
Phospholipide metabolism in cell fractions of regenerating liver

Abstract The P 32 uptake in a number of phosphorus-containing fractions of the nuclei, mitochondria, microsomes, and supernatant of liver cells was investigated in normal rat liver and during the premitotic and mitotic phases of liver “regeneration” following partial hepatectomy. The cephalins of all the cell fractions of the normal livers incorporated P 32 much faster than the lecithins, while the sphingomyelins incorporated it relatively slowly. The increased P32 uptake of the phospholipides observed earlier to be associated with mitotic activity can be accounted for by an increased P 32 uptake by the cephalins of the nucleus, by the lecithins of the mitochondria, microsomes, supernatant, and possibly the nuclei, and by the sphingomyelins of the supernatant. The data, viewed in the light of observations made in earlier studies, suggest that P 32 turnover in lecithin occurs in all parts of the cell during interphase; that of nuclear cephalins and of supernatant sphingomyelins occurs following preprophase and prior to or during metaphase processes.
Radiosynthesis and mouse brain distribution studies of [11C] CP-126,998: a PET ligand for in vivo study of acetylcholinesterase

Abstract The selective, reversible acetylcholinesterase inhibitor 5,7-Dihydro-7-methyl-3- [2-[1-(phenylmethyl]-4-piperidinyl]ethyl]-6 H -pyrrolo[3,2- f ]-1,2-benzisoxazol3–6-one (CP-126,998) was labeled with C-11 iodomethane via base-promoted alkylation of the lactam nitrogen. [ 11 C] CP-126,998 was synthesized in good radiochemical yield (13–29% non-decay corrected) and high specific radioactivity (177–418 GBq/μmol). In vivo mouse biodistribution studies reveal [ 11 C] CP-126,998 to localize preferentially in striatal tissue, a region known to be rich in acetylcholinesterase. Competitive blocking studies using a variety of acetylcholinesterase inhibitors (diisopropylfluorophosphate, tacrine, CP-118,954) verified the specificity of the PET radiotracer for brain acetylcholinesterase.
Electrocatalytic reduction of molecular oxygen at electrodes coated with a new cobalt(II)–platinum(II) bimetallic porphyrin

Cobalt(II) inserts into 5-(4-pyridyl)-10,15,20-(3,4-dimethoxyphenyl)porphyrin (1) by reaction of the porphyrin with the cobalt(II) acetate salt in refluxing N,N′-dimethylformamide solutions. When the porphyrin and the cobalt porphyrin are reacted with PtCl2(DMSO)2 in dichloromethane at ambient temperatures the platinum complex coordinates to the peripheral pyridyl group of the porphyrin. Roughened EPG electrodes coated with the cobalt(II)–platinum(II) bimetallic porphyrin, complex (4), show a 500 mV shift in the reduction of molecular oxygen in acidic media when compared to the bare electrode. Oxidation of the bimetallic porphyrin coated electrodes at 1.20 V versus saturated calomel electrode (SCE) results in an additional shift of ca 100 mV for the reduction of molecular oxygen when compared to the bimetallic porphyrin coated electrode prior to oxidation. In addition the oxidized surface shows the ability to reduce approximately 50% of the oxygen to water and the other 50% to hydrogen peroxide according ...
Determining the optimal block margin on the planning target volume for extracranial stereotactic radiotherapy

Abstract Purpose: To determine the block margin that minimizes normal tissue irradiation outside of the planning target volume (PTV) for body stereotactic radiotherapy (Body-SRT) of lung and liver tumors. Methods and Materials: Representative patient cases of lung and liver tumors were chosen for analysis. A PTV was constructed for each case and plans were generated which employed an array of block margins ranging from −2.5 mm to 10 mm at isocenter. Plans were generated for cerrobend blocks and for a multileaf collimator. The prescription isodose coverage was renormalized for each case and dose–volume histograms (DVH) and normal tissue complication probabilities (NTCP) were determined for each plan. Results and Conclusion: For the cases studied, the optimal block margin was in the 0.0 mm range. The ranking of plans was identical for both dose–volume based and biological based criteria. The method of blocking had no significant effect on treatment plans. The use of narrow margins for Body-SRT results in normal tissue sparing and creates significant target dose inhomogeneity which may be beneficial for tumor control.
Reexamination of ionospheric chemistry: high temperature kinetics, internal energy dependences, unusual isomers, and corrections

A number of aspects of ionospheric chemistry are revisited. The review discusses in detail only work performed at AFRL, but other work is mentioned. A large portion of the paper discusses measurements of the kinetics of upper ionospheric reactions at very high temperatures, i.e. the upper temperature range has been extended to at least 1400 K and in some cases to 1800 K. These temperatures are high enough to excite vibrations in O2, N2, and NO and comparing them to drift tube data allows information on the rotational temperature and vibrational level dependences to be derived. Rotational and translational energy are equivalent in controlling the kinetics in most reactions. Vibrational energy in O2 and N2 is often found to promote reactivity which is shown to cause ionospheric density depletions. NO vibrations do not significantly affect the reactivity. In a number of cases, detailed calculations accompanied the experimental studies and elucidated details of the mechanisms. Kinetics of two peroxide isomers important in the lower ionospheric have been measured for the first time, i.e. NOO+ and ONOO−. Finally, two examples are shown where errors in previous data are corrected.
A wavelet packet model of evoked potentials.

Abstract The standard methods for decomposition and analysis of evoked potentials are bandpass filtering, identification of peak amplitudes and latencies, and principal component analysis (PCA). We discuss the limitations of these and other approaches and introduce wavelet packet analysis. Then we propose the “single-channel wavelet packet model,” a new approach in which a unique decomposition is achieved using prior time–frequency information and differences in the responses of the components to changes in experimental conditions. Orthogonal sets of wavelet packets allow a parsimonious time–frequency representation of the components. The method allows energy in some wavelet packets to be shared among two or more components, so the components are not necessarily orthogonal. The single-channel wavelet packet model and PCA both require constraints to achieve a unique decomposition. In PCA, however, the constraints are defined by mathematical convenience and may be unrealistic. In the single-channel wavelet packet model, the constraints are based on prior scientific knowledge. We give an application of the method to auditory evoked potentials recorded from cats. The good frequency resolution of wavelet packets allows us to separate superimposed components in these data. Our present approach yields estimates of component waveforms and the effects of experiment conditions on the amplitude of the components. We discuss future extensions that will provide confidence intervals and p values, allow for latency changes, and represent multichannel data.
Role of the Per/Arnt/Sim domains in ligand-dependent transformation of the aryl hydrocarbon receptor

The aryl hydrocarbon receptor (AhR) mediates the toxic and biological effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin and related compounds. In a process termed transformation, ligand binding converts the AhR into its high affinity DNA binding form that represents a dimer of the AhR and Arnt, a closely related nuclear protein. During transformation, protein chaperone Hsp90 is thought to be replaced by Arnt in overlapping binding sites in the basic helix loop helix and PASB domains of the AhR. Here, analysis of AhR variants containing a modified PASB domain and AhR PASA-PASB fragments of various lengths revealed (i) an inhibitory effect on transformation concomitant with Hsp90 binding in the PASB domain, (ii) an ability of the PASA-PASB fragment of the AhR to reproduce key steps in the transformation process, and (iii) a ligand-dependent conformational change in the PASA domain consistent with increased PASA exposure during AhR transformation. Based on these results, we propose a new mechanism of AhR transformation through initiation of Arnt dimerization and Hsp90 displacement in AhR PASA/B domains. This study provides insights into mechanisms of AhR transformation, dimerization of PAS domain proteins, and Hsp90 dissociation in activation of its client proteins.
Interplay between cell cycle regulation and plant development

The regulation of cell cycle transitions is one of the most widely studied phenomena in biology, and studies in several model systems have revealed the basic machinery that drives these transitions. Although the core cell cycle machinery is conserved across evolution, its regulation has to be
Phylogeny of Orbirhynchia Pettitt, 1954 (Brachiopoda: Rhynchonellida)

A computer-based parsimony analysis of the brachiopod genus Orbirhynchia (Late Albian–Middle Campanian) is described. The resulting cladogram indicates that the genus divided into two distinct lineages soon after its appearance in the Late Albian. One group is known only from marly and sandy facies of Cenomanian age, while the second, more diverse, group appeared later in the Cenomanian but persisted into the Campanian. These two groups exhibit distinct morphological trends which may be related to different ecological niches, perhaps with respect to local sedimentary environment. Key words: brachiopod, Orbirhynchia, Cretaceous, phylogeny, palaeoecology.
Taste thresholds for sodium chloride in longitudinal experiments

Sumnzary.-A rapid ascending method of limits without standards was reliable for determining taste thresholds for NaCl in longirudinal experiments. Three experienced Ss made two judgments-tentative-uncertain and certain (absolure threshold) in each of five series of taste judgments daily for 120 consecutive days. To provide a means of studying functional relationships between taste and other variables, the total variance in all the judgments was partialled into several orthogonal components by means of linear components analysis. Factor scores computed from these components were correlated with a series of values derived direcrly from the judgments. The first component for each S consolidared the variance that arose from the average day-to-day differences in judgments, and the others isolated the variance that was due to within-day linear trends. The relation of the unrotated and rotated components was shown, and the reasons for our preference for the former were explained. The factor scores from these several components of variance may be viewed as new variables rhat measure these structural pools of variance and, as such, they may be correlated with any other pertinent variables such as constiruents of saliva, motivation, environmental temperature, and the like. Furthermore, the estimation of the "subliminal" threshold not only was reliable, but it expands the possibility for clarification of the nature of taste percepts.
Thrombose aortique due à une thrombocytose essentielle : stratégies de traitement médical et chirurgical

La thrombocytose essentielle (TE) reste une cause rare de maladie thrombo-embolique de l'aorte. Les options therapeutiques varient suivant la presentation clinique et vont de l'observation sous traitement medical a l'intervention chirurgicale immediate. Nous rapportons un cas de TE entrainant des microembolies distales a partir d'un thrombus aortique. Le malade eut un traitement cytoreducteur approprie puis une resection-greffe aortique. Nous discutons les diverses strategies therapeutiques possibles.
Monodisperse face-centred tetragonal FePt nanoparticles with giant coercivity

Monodisperse face-centred tetragonal (fct) FePt nanoparticles with high magnetic anisotropy and, therefore, high coercivity have been prepared via a new heat treatment route. The as-synthesized face-centred cubic FePt nanoparticles were mixed with salt powders and annealed at 700uC. The salts were then removed from the particles by washing the samples in water. Monodisperse fct FePt particles were recovered with the particle size and shape being retained. Coercivity of the isolated particles up to 30 kOe at room temperature has been obtained. (Some figures in this article are in colour only in the electronic version)
The Bubbling Universe

The scenario of an expanding universe envisioned in the early part of the 20th century has been replaced by one where we live in a chaotic, eternally bubbling universe. Every bubble has the potential for developing into a new habitable universe. In this essay I describe how large-scale quantum effects could be driving the chaotic bubbling universe.
Absence of mutations in the p53 tumor suppressor gene in woodchuck hepatocellular carcinomas associated with hepadnavirus infection and intake of aflatoxin B1

Infection with hepadnaviruses and exposure to aflatoxin B 1 (AFB 1 ) are considered major risk factors in the development of hepatocellular carcinoma (HCC) in humans and in animals. A high rate of mutations in the p53 tumor suppressor gene in hepatocellular carcinomas of predominantly hepatitis B virus (HBV) carrier patients has been recently related to dietary aflatoxin. Another member of the hepadnavirus family, the woodchuck hepatitis virus (WHV), infects woodchucks in a manner similar to that of HBV in humans. Therefore, it was of particular interest to determine whether the p53 gene in woodchuck HCCs associated with hepadnavirus infection and with exposure to AFB 1 is affected in the same manner as in human HCCs. By direct PCR-sequencing, we analyzed exons 4-9 of the p53 gene in 13 HCCs from 12 woodchucks (two uninfected, ten WHV carriers). Six WHV carrier and two uninfected woodchucks were treated with AFB 1 . None of the analyzed HCC samples exhibited mutations, either in p53 gene exons 4-9, or in splicing donor-acceptor sites. The present data are consistent with our previous study that indicated a low rate of p53 mutations in HCCs of AFB 1 -treated ground squirrels, either infected or not infected with ground squirrel hepatitis virus, and in WHV carrier woodchucks not exposed to AFB 1 . Overall, our findings indicate that in woodchucks and in ground squirrels exposure to aflatoxin may affect the development of p53 mutations less than in humans.
BMI, life-style and psychological conditions in a sample of elderly Italian men and women.

To identify the relationship among cognitive status, psychological conditions, anthropometric measurements and life-style in a sample of elderly Italian men and women. Three hundred and six volunteers for ZINCAGE Project recruited. The sample was made up of healthy older adults living in the Marche Region aged 65 and over. All elderly were given a complete medical, anthropometric assessment, and psycho-social evaluation. Overall, the participants perceived themselves to be in very good or good (22%) or fair (69%) health; only 9% reported a poor health status. The 46% of the sample fell within the normal body mass index (BMI) range, though 38% were overweight, 12% were obese, and only 4% were underweight. In both sexes, BMI significantly decreased with age (p<0.001). BMI was positively associated with performing sedentary activities (r = 0.188; p < 0.001). Levels of both sedentary (r = 0.221; p < 0.001) and non-sedentary (r = 0.258; p < 0.001) leisure activities were positively associated with education level (p<0.05). It was found that lower scores of physical activity were associated to higher scores of Geriatric Depression Scale (r=−0.425; p<0.01), lower scores of Mini Mental State Examination (r=0.266; p<0.001) and higher score of Perceived Stress Scale (r=−0.131; p<0.05). Men and women lead different lifestyles and have a different psychological status, with advancing age consequently stressing the need for healthy lifestyle programmes particularly in the case of overweight and obese elderly people.
Should i stay or should i go: two features to help people stop an exploratory search wisely

In today's "overloaded" information environment, deciding a stopping point for an exploratory search is not an easy decision. In this paper, we present the design and implementation of two search techniques: Result Preview (RP) and History Review (HR), to help people assess whether the information gained is enough and decide if he/she should quit or continue. Both RP and HR are utilizing visual presentations to release people from the demanding cognitive requirements needed for an exploratory search. A formal user experiment with 24 participants is proposed to evaluate the benefits and limitations, and also inform the future RP and HR design.
A client-side web application for interactive environmental simulation modeling

Recent developments in web technologies including evolution of web standards, improvements in browser performance, and the emergence of free and open-source software (FOSS) libraries are driving a general shift from server-side to client-side web applications where a greater share of the computational load is transferred to the browser. Modern client-side approaches allow for improved user interfaces that rival traditional desktop software, as well as the ability to perform simulations and visualizations within the browser. We demonstrate the use of client-side technologies to create an interactive web application for a simulation model of biochemical oxygen demand and dissolved oxygen in rivers called the Web-based Interactive River Model (WIRM). We discuss the benefits, limitations and potential uses of client-side web applications, and provide suggestions for future research using new and upcoming web technologies such as offline access and local data storage to create more advanced client-side web applications for environmental simulation modeling. A client-side web application of an environmental simulation model is presented.Client-side computation and visualization support high interactivity and usability.URL-based model access and a commenting system promote user collaboration.Web-based simulation models are more accessible to non-technical users.
Demonstration of sub-femtomole sensitivity for small molecules with microsphere ring resonator sensors

Optical microsphere resonators can function as highly sensitive bio/chemical sensors due to the large Q-factor, which leads to high light-matter interaction. The whispering gallery modes (WGM) arise at the surface of the microsphere, creating a highly enhanced optical field that interacts with matter on or near the microsphere surface. As a result, the spectral position of the WGM is extremely sensitive to refractive index changes near the surface, such as when bio/chemical molecules bind to the sphere. We show the potential feasibility of a microsphere ring resonator as a sensor for small molecules by demonstrating detection of sub-femtomole changes in SiO2 molecules at the surface of the microsphere. In this experiment, the silica molecules act as an excellent model for small molecule analytes because of their 60 Dalton molecular weight, and because we know nearly the exact quantity of molecules at the surface, which enables a sensitivity characterization. We measure the spectral shifts in the WGMs when low concentrations of hydrofluoric acid (HF) are added to a solution that is being probed by the microsphere. As the HF molecules break apart the SiO2 molecules at the sphere surface, the WGMs shift due to the sub-nano-scale decrease in the size of the microsphere. These calculations show that the sensitivity of this microsphere resonator is on the order of 500 attomoles. Our results will lead to the utilization of optical microspheres for detection of trace quantities of small molecules for such applications as drug discovery, environmental monitoring, and enzyme detection using peptide cleavage.
Sex differences in dendritic patterns in hamster preoptic area.

Sexual dimorphism is described in the dendritic field pattern of Golgi-stained neurons from the dorsomedial preoptic area of adult golden hamsters (Mesocricetus auratus). Data were obtained through a mathematical reconstruction of dendritic densities of neurons sampled from this area in males and females. Males tended to have a central concentration, while females showed an irregular dendritic density distribution with concentrations dorsolateral, ventral and medial to the area of highest dendritic density in the males. These results suggest sex differences in the afferent inputs to neurons in the dorsomedial preoptic area which may be related to functional sexual dimorphism in physiology and behavior.
Numerical evaluation of pumping well transmissivity estimates in laterally heterogeneous formations

Transmissivity estimates derived from non-steady-state, single well, constant discharge, aquifer tests in laterally heterogeneous environments generally are questioned relative to their representativeness of aquifer conditions. Drawdown in pumping wells reflects the removal of water from storage in the aquifer and transient refraction of groundwater path-lines during the evolution of a non-symmetrical cone of depression. Simulations of single-well aquifer tests in aquifers with simple, arbitrary distributions of block heterogeneities suggest that transmissivity (T) values derived by the Cooper–Jacob (1946) method generally reflect volumetric, weighted mean T values of all of the heterogeneities contacted by the cone of depression at a particular time. This finding suggests that early-time drawdown data for single well aquifer tests reflect rapidly changing, volumetric, weighted mean T values proximal to the pumping well while late-time drawdown data reflect stabilized conditions and spatially averaged, volumetric weighted mean T out to a considerable distance from the pumping well.
An electrostatic model for the dielectric effects, the adsorption of multivalent ions, and the bending of B-DNA

We have studied electrostatic properties of DNA with a discrete charge model consisting of a cylindrical dielectric core with a radius of 8 A and a dielectric constant Di = 4, surrounded by two helical strings of phosphate point charges at 10 A from the axis, immersed in an aqueous medium with dielectric constant Dw = 78.54. Eliminating the dielectric core makes potentials in the phosphate surface less negative by about 0.5 kT/e. Salt effects are evaluated for the model without a dielectric core, using the shielded Coulomb potential. Smearing the phosphate charges increases their potential by about 2.5 kT/e, due mostly to the self-potential of the smeared charge. Potentials in the center of the minor and major grooves vary less than 0.02 kT/e along their helical path. The potential in the center of the minor groove is from 1.0 to 1.7 kT/e, more negative than in the center of the major groove, depending on dielectric core and salt concentration. So multivalent cations and also larger cationic ligands, such as some antibiotics, are likely to adsorb in the minor groove, in agreement with earlier computations by A. and B. Pullman. Dielectric effects on the surface potential and the local potential variations are found to be relatively small. Bending of DNA is studied by placing a multivalent cation, MZ+, in the center of the minor or major groove, curving DNA around it for a certain length, and calculating the free energy difference between the bent and the straight configuration. Boltzmann averaged bending angles, 〈β〉, are found to be maximal in 0.03M monovalent salt, for a length of about 50 or 25 A of curved DNA when an MZ+ ion is adsorbed in the minor or the major groove, respectively. When the dielectric constant of water is used throughout the calculation, we find maximal bends of 〈β〉 = 11° for M2+ and 〈β〉 = 16° for M3+ in the minor groove, 〈β〉 = 13° for M3+ in the major groove. The absence of bends in DNA adsorbed to mica in the presence of Mg salts supports the role of Mg2+ in “ion bridging” between DNA and mica. The treatment of the effective dielectric constant between two points outside a dielectric cylinder in water is appended. © 1998 John Wiley & Sons, Inc. Biopoly 46: 503–516, 1998
Challenges of designing hepatic encephalopathy treatment trials.

Background/Aims: The efficacy and safety of rifaximin in comparison with lactitol in the treatment of hepatic encephalopathy was assessed in a prospective randomized, double-blind, double-dummy, controlled trial. Methods: A total of 103 patients with grade I-III acute hepatic encephalopathy were randomized to receive rifaximin (50 patients, 1200 mg/day) or lactitol (53 patients, 60 g/day) for 5-10 days. Changes in portal-systemic encephalopathy (PSE) index on entry and at the end of the study were used to evaluate the efficacy of the two therapies. Results: Both groups were comparable before treatment with regard to demographic data and characteristics of the hepatic encephalopathy episode. The global efficacy of both therapies was similar: 81.6% in the rifaximin group and 80.4% in the lactitol group showed improvement or total regression of the episode. A significantly better evolution of the PSE index was observed in the rifaximin group, due to a greater effect of rifaximin in two components of the index: EEG abnormalities and ammonia levels. No serious events related to either treatment were found during the study. Conclusions: Rifaximin may be considered a useful and safe alternative therapy to lactitol in the treatment of acute hepatic encephalopathy in cirrhosis.
Extracellular Matrix Oxidation Modulates Survival, NF-κB Translocation, and MAPK Activity in Mesangial Cells

Abstract Inflammatory injury to the kidney may oxidize extracellular matrix proteins. These changes appear to impair adhesion of glomerular mesangial cells and might impact signaling mechanisms in these cells. In this study we evaluated how extracellular matrix oxidation could modulate the development of apoptosis as well as the activity of the transcription factor NF-κB and that of the MAPK family members ERK-1,2 and JNK. Exposure of mesangial cells to oxidized matrix enhanced the percentage of apoptotic cells. Western blot analysis revealed diminished levels of the phosphorylated form of ERK-1,2 in cells on oxidized matrix, while levels of phosphorylated JNK were increased. Cells on unmodified matrix were found to have rapid translocation of the p65 subunit of NF-κB, which was attenuated in cells on oxidized matrix. These findings suggest that extracellular matrix oxidation may impair survival of mesangial cells in association with decreased levels of pERK-1,2, increased levels of pJNK, and diminished nuclear translocation of the transcription factor NF-κB.
Plankton community structure and export of C, N, P and Si in the Antarctic Circumpolar Current

Abstract We analyzed the relationship between the estimated export (ei) of carbon, nitrogen, silica and phosphorus from the surface ∼90 m in the Antarctic Circumpolar Current (ACC) region along 170 °W and the seasonal development of the epipelagic community. Export was based on nutrient budgets from repeat sections during the 1997–1998 austral summer to estimate nutrient specific, net community production (NCPi; Green and Sambrotto, 2006). We adjusted NCPi for changes in surface-water particulate material and dissolved organic matter to isolate ei on an approximately monthly basis in four meridional regimes. Estimates of eC, eN and eSi from October to March ranged from 1.9–2.7, 0.11–0.34 and 1.0–2.7 moles m−2 season−1. Although the meridional trends in our export estimates were similar to previously published trends that suggest an increase in carbon export south of the front, our estimates north of the front were about 30% higher than prior estimates in the region. Typically, the peak of eN (and eP) was 4–6 weeks before that for eSi and eC. The lag between eN and eC was similar to the lag between new production and 234Th-based eC in the region as well as similar lags found in upwelling water of the equatorial Pacific and the Arabian Sea. We suggest that this lag is characteristic of physically perturbed regions and reflects the temporal development of the grazing community, a time scale that appears to vary little, despite a 20 °C difference in temperature. Based on pigment markers and direct microscopic analyses, the growth of heavily silicified Fragilariopsis spp. south of the Antarctic Polar Front (APF) was associated with a rapid increase in eSi in December as the ice retreated. However, elevated eC continued at high levels as the diatom community disappeared (particularly in the north). Later successional forms such as Chaetoceros spp. and Corethron spp. appeared to enhance eC by facilitating aggregation. Thus, the seasonal pattern of eC in the ACC was impacted by the nature of the diatom community and was not a simple function of total opal concentration. This aggregator community promoted elevated eC even at relatively low concentrations of diatoms north of the APF. The pigment markers also reflected other important environmental associations including dinoflagellates with the APF and Phaeocystis with the melt water from the retreating ice. Export ratios deviate from Redfield and suggest a combination of environmental and taxonomic influences. Diatom growth early in the season was associated with low eN/eP ratios and the depletion of iron in January was associated with elevated eSi/eN ratios.
Emergency department triage strategies for acute chest pain using creatine kinase-MB and troponin I assays: A cost-effectiveness analysis

Measurement of creatine kinase–MB mass plus early exercise testing is a cost-effective initial strategy for younger patients and those with a low to moderate probability of myocardial infarction. T...
Uncovering New Functions for microRNAs in Caenorhabditis elegans

In the nematode Caenorhabditis elegans, microRNA (miRNA) regulation of development was first observed in the striking abnormalities of lin-4 and let-7 loss of function mutants. However, after these first two miRNA mutant phenotypes were described, progress on the identification of miRNA functions in worms slowed considerably. Recent advances reveal new functions for miRNAs in embryonic and larval development as well as in the regulation of lifespan and stress response. Results from a combination of computational, biochemical, and genetic approaches have deepened our understanding of miRNA regulation of target mRNAs and support the hypothesis that miRNAs have an important role in ensuring the robustness of developmental and physiological pathways.
Theoretical studies on farnesyl cation cyclization: pathways to pentalenene

In this article, we describe studies, using quantum chemical computations, on possible polycyclization pathways of the farnesyl cation leading to the complex sesquiterpene pentalenene. Two distinct pathways to pentalenene with similar activation barriers are described, each differing from previous mechanistic proposals, and each involving unusual and unexpected intermediates. Direct deprotonation of intermediates on these pathways leads to sesquiterpene byproducts, such as humulene, protoilludene, and asteriscadiene, supporting the notion that a key function of pentalenene synthase, the enzyme that produces pentalenene in Nature, is to regulate the timing and location of proton removal. The implications of the computational results for experimental studies on pentalenene synthase are discussed.
Intravenous heroin self‐administration decreases GABA efflux in the ventral pallidum: an in vivo microdialysis study in rats

Several lines of evidence suggest that opiate-induced disinhibition of the ventral pallidum participates in the mediation of opiate reward, though direct in vivo evidence to support this hypothesis has been lacking. The present experiment tested this hypothesis by investigating alterations in ventral pallidal amino acid efflux using in vivo microdialysis during ongoing intravenous heroin self-administration in rats. Concentrations of the inhibitory amino acid GABA in ventral pallidal dialysates were significantly reduced within the first 10 min of heroin self-administration (0.02 mg per infusion; FR-1), and remained approximately 65% of presession baseline levels for the remainder of the 3-h self-administration session. Dialysate glutamate levels were unaltered during the first hour of heroin intake but significantly increased to a stable level of approximately 120% presession values during the subsequent 2 h of self-administration. Thus, heroin self-administration is associated with both decreased GABA efflux and a late phase increase in glutamate efflux in the ventral pallidum. These observations are consistent with the hypothesis that heroin self-administration results in a disinhibition and/or excitation of the ventral pallidum.
The Rhetoric Revision Log A Technique for Teaching Rhetorical Features in ESL Writing

The current study reports on the “rhetoric revision log,” which was developed to help second language writing students track their progress in improving rhetoric-related issues in their writing (such as organization and topic development). Sixty-six English as a second language (ESL) students were divided into one control and two treatment groups. Students in the two treatment groups used the rhetoric revision log to keep a record of teacher written feedback in several rhetoric-related areas throughout the course of one semester. The two treatment groups differed in that in one the students used only the log (log-only), while in the other (log + conference) students also participated in structured writing conferences in which the teacher discussed the rhetoric revision log with the students. Results revealed that both treatment groups improved more in their overall writing ability than the control group. Moreover, students in the log + conference group were more likely than the other two groups to improve in rhetoric-related writing features over the course of the semester. These findings suggest that using the rhetoric revision log helped students improve not only rhetoric-related aspects of their writing, but also their overall writing ability.
HUMAN FIXED-INTERVAL PERFORMANCE WITH CONCURRENTLY PROGRAMMED SCHEDULES: A PARAMETRIC ANALYSIS

Young adults pressed a lever for points, exchangeable for money, programmed on concurrent schedules in which one component was a fixed-interval and the other component either a fixed-ratio (Experiment 1) or a differential-reinforcement-of-low-rate (Experiment 2). Two general patterns of fixed-interval responding, postreinforcement pause or constant rate, occurred in both experiments as a function of the parameter values of each component. Also patterns of interaction between the component schedules developed, in which responding or point delivery on one component appeared to be discriminative for responding on the other component. Once a pattern of responding was established, it tended to persist when the parameter values of the schedule were changed. On many schedules, subjects with an experimental history responded differently than did naive subjects, although certain schedule values were resistant to the history effects. The role of verbal strategies in mediating history effects was discussed.
Watershed nitrogen input and riverine export on the west coast of the US

This study evaluated the sources, sinks, and factors controlling net export of nitrogen (N) from watersheds on the west coast of the US. We calculated input of new N to 22 watersheds for 1992 and 2002. 1992 inputs ranged from 541 to 11,644 kg N km−2 year−1, with an overall area-weighted average of 1,870 kg N km−2 year−1. In 2002, the range of inputs was 490–10,875 kg N km−2 year−1, averaging 2,158 kg N km−2 year−1. Fertilizer was the most important source of new N, averaging 956 (1992) and 1,073 kg N km−2 year−1 (2002). Atmospheric deposition was the next most important input, averaging 833 (1992) and 717 kg N km−2 year−1 (2002), followed by biological N fixation in agricultural lands. Riverine N export, calculated based on measurements taken at the furthest downstream USGS water quality monitoring station, averaged 165 (1992) and 196 kg N km−2 year−1 (2002), although data were available for only 7 watersheds at the latter time point. Downstream riverine N export was correlated with variations in streamflow (export = 0.94 × streamflow − 5.65, R 2 = 0.66), with N inputs explaining an additional 16% of the variance (export = 1.06 × streamflow + 0.06 × input − 227.78, R 2 = 0.82). The percentage of N input that is exported averaged 12%. Percent export was also related to streamflow (%export = 0.05 × streamflow − 2.61, R 2 = 0.60). The correlations with streamflow are likely a result of its large dynamic range in these systems. However, the processes that control watershed N export are not yet completely understood.
Photoconduction of rapidly quenched films in the PbOTiO2 system

The PbOTiO2 films were prepared by a rapid quenching technique using a twin-roller type equipment. The quenched films containing from 10 to 30 mol% TiO2 precipitated tetragonal PbO solid solution as single phase. The PbTiO3 crystal precipitated from the melt of equimolar composition of PbO and TiO2 had a denser structure and a lower tetragonality compared to that obtained by solid phase reaction. In the films containing 60 mol% TiO2 or above, the formation of amorphous phase was predominant. Crystalline films, as well as PbTiO3 film, showed photoconductivity.
Embedded video coding using invertible motion compensated 3-D subband/wavelet filter bank

Abstract In this paper, we present a new embedded video coding system with local motion compensation. An invertible motion compensated 3-D subband filter bank is utilized for video analysis/synthesis. The efficient embedded image coding scheme EZBC is extended to 3-D coding of video subbands. The coded bitstream is rate scalable and fully embedded thus meeting the increasing need for fine granular scalability in video streaming applications. Our experimental results show the new algorithm outperforms nonscalable standard MPEG-2 by 0.8– 3.3 dB (luminance component) over a broad range of bitrates, while providing an embedded video bitstream. Unlike conventional SNR hybrid coders, this multirate property is achieved without a loss in compression efficiency. Comparisons are also made to two other competing embedded video coders, LZC and 3D-SPIHT, both based on 3-D subband coding as well. The new coder demonstrates a significant advantage for encoding video with high local motion content, thanks to the efficient inclusion of local motion information in the temporal filter bank of our proposed system.