cssi/SciSciGPT-SciSciNet huggingface dataset:
Structural Organization of FtsB, a Transmembrane Protein of the Bacterial Divisome.

We report the first structural analysis of an integral membrane protein of the bacterial divisome. FtsB is a single-pass membrane protein with a periplasmic coiled coil. Its heterologous association with its partner FtsL represents an essential event for the recruitment of the late components to the division site. Using a combination of mutagenesis, computational modeling, and X-ray crystallography, we determined that FtsB self-associates, and we investigated its structural organization. We found that the transmembrane domain of FtsB homo-oligomerizes through an evolutionarily conserved interaction interface where a polar residue (Gln 16) plays a critical role through the formation of an interhelical hydrogen bond. The crystal structure of the periplasmic domain, solved as a fusion with Gp7, shows that 30 juxta-membrane amino acids of FtsB form a canonical coiled coil. The presence of conserved Gly residue in the linker region suggests that flexibility between the transmembrane and coiled coil domains is functionally important. We hypothesize that the transmembrane helices of FtsB form a stable dimeric core for its association with FtsL into a higher-order oligomer and that FtsL is required to stabilize the periplasmic domain of FtsB, leading to the formation of a complex that is competent for binding to FtsQ, and to their consequent recruitment to the divisome. The study provides an experimentally validated structural model and identifies point mutations that disrupt association, thereby establishing important groundwork for the functional characterization of FtsB in vivo.
The prospects for gene therapy.

Gene therapy will probably not be inordinately complex. Although extremely hightech in its design and manufacture, it is likely to be easy to administer in most practice settings. It will be widely used for classic genetic and common diseases alike.
A methodology for the real world

Register allocation may be viewed as a graph coloring problem. Each node in the graph stands for a computed quantity that resides in a machine register, and two nodes are connected by an edge if the quantities interfere with each other, that is, if they are simultaneously live at some point in the object program. This approach, though mentioned in the literature, was never implemented before. Preliminary results of an experimental implementation in a PL/I optimizing compiler suggest that global register allocation approaching that of hand-coded assembly language may be attainable.
RecFOR Proteins Load RecA Protein onto Gapped DNA to Accelerate DNA Strand Exchange: A Universal Step of Recombinational Repair

Genetic evidence suggests that the RecF, RecO, and RecR (RecFOR) proteins participate in a common step of DNA recombination and repair, yet the biochemical event requiring collaboration of all three proteins is unknown. Here, we show that the concerted action of the RecFOR complex directs the loading of RecA protein specifically onto gapped DNA that is coated with single-stranded DNA binding (SSB) protein, thereby accelerating DNA strand exchange. The RecFOR complex recognizes the junction between the ssDNA and dsDNA regions and requires a base-paired 5' terminus at the junction. Thus, the RecFOR complex is a structure-specific mediator that targets recombinational repair to ssDNA-dsDNA junctions. This reaction reconstitutes the initial steps of recombinational gapped DNA repair and uncovers an event also common to the repair of ssDNA-tailed intermediates of dsDNA-break repair. We propose that the behavior of the RecFOR proteins is mimicked by functional counterparts that exist in all organisms.
End-functionalized ROMP polymers for Biomedical Applications.

We present two novel allyl-based terminating agents that can be used to end-functionalize living polymer chains obtained by ring-opening metathesis polymerization (ROMP) using Grubbs’ third generation catalyst. Both terminating agents can be easily synthesized and yield ROMP polymers with stable, storable activated ester groups at the chain-end. These end-functionalized ROMP polymers are attractive building blocks for advanced polymeric materials, especially in the biomedical field. Dye-labeling and surface-coupling of antimicrobially active polymers using these end-groups were demonstrated.
A steep radioiodine dose response scalable to humans in sodium-iodide symporter (NIS)-mediated radiovirotherapy for prostate cancer.

The sodium-iodide symporter (NIS) directs the uptake and concentration of iodide in thyroid cells. We have extended the use of NIS-mediated radioiodine therapy to prostate cancer. We have developed a prostate tumor specific conditionally replicating adenovirus that expresses hNIS (Ad5PB_RSV-NIS). For radiovirotherapy to be effective in humans, the radioiodine dose administered in the pre-clinical animal model should scale to the range of acceptable doses in humans. We performed 131I dose-response experiments aiming to determine the dose required in mice to achieve efficient radiovirotherapy. Efficacy was determined by measuring tumor growth and survival times. We observed that individual tumors display disparate growth rates that preclude averaging within a treatment modality indicating heterogeneity of growth rate. We further show that a statistic and stochastic approach must be used when comparing the effect of an anti-cancer therapy on a cohort of tumors. Radiovirotherapy improves therapeutic value over virotherapy alone by slowing the rate of tumor growth in a more substantial manner leading to an increase in survival time. We also show that the radioiodine doses needed to achieve this increase scaled well within the current doses used for treatment of thyroid cancer in humans.
Distributed task migration for thermal management in many-core systems

In the deep submicron era, thermal hot spots and large temperature gradients significantly impact system reliability, performance, cost and leakage power. As the system complexity increases, it is more and more difficult to perform thermal management in a centralized manner because of state explosion and the overhead of monitoring the entire chip. In this paper, we propose a framework for distributed thermal management for many-core systems where balanced thermal profile can be achieved by proactive task migration among neighboring cores. The framework has a low cost agent residing in each core that observes the local workload and temperature and communicates with its nearest neighbor for task migration/exchange. By choosing only those migration requests that will result balanced workload without generating thermal emergency, the proposed framework maintains workload balance across the system and avoids unnecessary migration. Experimental results show that, compared with existing proactive task migration technique, our approach generates less hotspots and smoother thermal gradient with less migration overhead and higher processing throughput.
Existence and nonexistence of positive solutions for quasilinear systems

The paper deals with the existence and nonexistence of positive solutions for a class of -Laplacian systems. We investigate the effect of the size of the domain on the existence of positive solution for the problem in sublinear cases. We will use fixed point theorems in a cone.
Gating charge interactions with the S1 segment during activation of a Na+ channel voltage sensor.

Voltage-gated Na+ channels initiate action potentials during electrical signaling in excitable cells. Opening and closing of the pore of voltage-gated ion channels are mechanically linked to voltage-driven outward movement of the positively charged S4 transmembrane segment in their voltage sensors. Disulfide locking of cysteine residues substituted for the outermost T0 and R1 gating-charge positions and a conserved negative charge (E43) at the extracellular end of the S1 segment of the bacterial Na+ channel NaChBac detects molecular interactions that stabilize the resting state of the voltage sensor and define its conformation. Upon depolarization, the more inward gating charges R2 and R3 engage in these molecular interactions as the S4 segment moves outward to its intermediate and activated states. The R4 gating charge does not disulfide-lock with E43, suggesting an outer limit to its transmembrane movement. These molecular interactions reveal how the S4 gating charges are stabilized in the resting state and how their outward movement is catalyzed by interaction with negatively charged residues to effect pore opening and initiate electrical signaling.
Unpacking the thinking and making behind a user enactments project

We have developed User Enactments to help support design teams in more successfully investigating radical alterations to technologies' roles, forms and behaviors in uncharted design spaces. To date, no work exists that explicitly unpacks the practical development of a cohesive set of user enactments. Interest is growing in the method with its recent inclusion in a popular design method handbook for practitioners and also as it becomes integrated into graduate-level university curriculum in interaction design. The contribution of this Pictorial is to unpack the thinking and making behind a set of user enactments through visual documentation and annotations.
And along came a spider: An attentional bias for the detection of spiders in young children and adults

Spiders are among the most common targets of fears and phobias in the world. In visual search tasks, adults detect their presence more rapidly than other kinds of stimuli. Reported here is an investigation of whether young children share this attentional bias for the detection of spiders. In a series of experiments, preschoolers and adults were asked to find the single spider picture among an array of eight mushrooms or cockroaches or the reverse. Both children and adults detected the presence of spiders more rapidly than both categories of distracter stimuli. Furthermore, there was no difference between the detection of two neutral stimuli (cockroaches vs. mushrooms). These results provide the first evidence of enhanced visual detection of spiders in young children.
Systematics of Low Energy Collective States in neutron-rich Cd Isotopes

It has been shown that there are significant deviations from the expected U(5) dynamical symmetry for 110,112,114,116Cd. However, there is very significant mixing with intruder states in this region. In this paper, we investigated states in the heavier 120,124,126Cd populated via beta decay. These nuclei exhibit similar patterns to the lighter Cd isotopes even though the intruder states are much higher in energy.
Particles exhibiting oxidative enzyme activity in yeast

Abstract 1. 1. Cytochrome oxidase activity in a cell-free preparation from yeast is associated with flattened spherical vesicles ranging from 0.2 μ to over 1 μ and sedimenting between 5000 × g and 26,000 × g . 2. 2. The 26,000 × g supernatant contains minute particles approximately 30 mμ in diameter, and the fatty layer at the top of the centrifuge tube contains fat droplets and lipid granules about 0.3 μ in diameter. Neither of these particles exhibit cytochrome oxidase activity. 3. 3. The structures found in ultrathin sections of the particle preparation are compared with those observed in whole yeast cells and in the exudate of broken cells with the phase contrast microscope. They are also compared with the known structures of cell-free preparations from liver. The enzymatically inactive lipid granules found in the fatty layer are identical with the refractile granules visible in the whole cell which have often been described as mitochondria on the basis of their staining reactions. Some of the vesicles appear to be derived from swollen mitochondria and others from other cytoplasmic elements. 4. 4. Variation in these cellular structures with growth conditions has been studied, particularly the reduction in lipid granules in yeast grown under anaerobic conditions, and the marked increase in these granules with aeration of such anaerobic cells.
Applicability of the Weibull distribution function to atmospheric radioactivity data

Abstract The Weibull distribution function is applied empirically to assemblages of atmospheric radioactivity data. Applications are presented in an exemplary fashion so as to acquaint the reader with the broad versatility of the treatment. The Weibull function is applicable to the temporal and spatial distributions of homogeneous atmospheric tritium oxide data, and to the temporal distributions of nonhomogeneous gross-beta and plutonium-239 atmospheric radioactivity data. Weibull distribution parameters are used to interpret different data sets in terms of physical mechanisms responsible for the observed distributions. Furthermore, the Weibull treatment provides an estimate of the minimum possible value of the quantity under investigation.
Congenital ventriculo-atrial communication with anomalous tricuspid valve.

Abstract A case of left ventricular-right atrial communication associated with a saccular aneurysm of the septal leaflet of the tricuspid valve is presented, with inclusion of cardiac catheterization, operative, and postmortem findings. The anatomic defect involved a communication between right atrium and left ventricle at a level just below the right coronary cusp of the aortic valve through the membranous portion of the interventricular septum. Perhaps the most unusual feature of the anomaly was the presence of the deep saccular aneurysm of the septal leaflet of the tricuspid valve at the site of the defect, projecting upward into the outflow tract of the right ventricle. The preoperative differentiation of this lesion from interatrial septal defect is difficult and the individual differences observed in this case are not specific. However, the combined findings of a loud harsh systolic murmur to the left of the sternum maximal over the lower precordium, and a prominent “c” wave in the atrial pulse pressure tracing are suggestive of a ventriculo-atrial type communication when a left to right shunt exists at the atrial level. The operative demonstration of a systolic jet of oxygenated blood from a defect in the right atrial wall in the region of the tricuspid annulus is presumptive evidence of such a communication. Since the lesion has proved to be surgically correctible, the importance of its recognition is stressed.
Custom Bifurcated Stent-Graft for Abdominal Aortic Aneurysms: Initial Experience

Purpose To describe a custom bifurcated stent-graft for possible treatment of abdominal aortic aneurysm (AAA). Materials and Methods Five male patients (mean age, 76 ± 6 years), who had AAA (mean diameter, 4.7 ± 0.4 cm) and who were considered to be at high risk for conventional surgery, were treated with a custom modular bifurcated stent-graft constructed with bifurcated 24-mm x 12-mm (upper body diameter x iliac limb diameter) Cooley Veri-Soft Woven polyester grafts and Gianturco-Rosch Z stents. The stent-graft body was delivered through 20-22-F sheaths, and the contralateral iliac limb was delivered through a 16-F sheath by means of surgical exposure of the common femoral arteries. A flared distal limb extender (12 mm to 14 mm) was created for one patient to accommodate a large common iliac artery. Results Stent-grafts were successfully deployed without complications in all five patients. There were no proximal or distal leaks. A lumbar-to-inferior mesenteric artery leak was seen in one patient at 24 hours. At 6-month follow-up, all devices were intact, with complete exclusion and shrinkage of the aneurysm in four of five patients. Aneurysm size remained stable in the one patient with a lumbar-to-inferior mesenteric artery leak. Conclusion A custom, bifurcated stent-graft was utilized for endovascular treatment of AAA. Long-term follow-up is necessary for the device.
Selection of nest‐site habitat by interior least terns in relation to sandbar construction

Federally endangered interior least terns (Sternula antillarum) nest on bare or sparsely vegetated sandbars on midcontinent river systems. Loss of nesting habitat has been implicated as a cause of population declines, and managing these habitats is a major initiative in population recovery. One such initiative involves construction of mid-channel sandbars on the Missouri River, where natural sandbar habitat has declined in quantity and quality since the late 1990s. We evaluated nest-site habitat selection by least terns on constructed and natural sandbars by comparing vegetation, substrate, and debris variables at nest sites (n = 798) and random points (n = 1,113) in bare or sparsely vegetated habitats. Our logistic regression models revealed that a broader suite of habitat features was important in nest-site selection on constructed than on natural sandbars. Odds ratios for habitat variables indicated that avoidance of habitat features was the dominant nest-site selection process on both sandbar types, with nesting terns being attracted to nest-site habitat features (gravel and debris) and avoiding vegetation only on constructed sandbars, and avoiding silt and leaf litter on both sandbar types. Despite the seemingly uniform nature of these habitats, our results suggest that a complex suite of habitat features influences nest-site choice by least terns. However, nest-site selection in this social, colonially nesting species may be influenced by other factors, including spatial arrangement of bare sand habitat, proximity to other least terns, and prior habitat occupancy by piping plovers (Charadrius melodus). We found that nest-site selection was sensitive to subtle variation in habitat features, suggesting that rigor in maintaining habitat condition will be necessary in managing sandbars for the benefit of least terns. Further, management strategies that reduce habitat features that are avoided by least terns may be the most beneficial to nesting least terns. © 2011 The Wildlife Society.
Eigenvalue degeneracy of the eight-vertex transfer matrix

Abstract We show for finite or infinite volume that the degeneracy of the maximum eigenvalue of the eight-vertex transfer matrix is the same above and below the critical temperature. A degeneracy of the maximum eigenvalue and a symmetry change in the eigenvectors of the transfer matrix provide the “mathematical mechanism” for the phase transition.
Study of the effects of concomitant elements in inductively coupled plasmamass spectrometry

Abstract The effect of 0.01 M concentrations of several concomitant elements (Li, Na, K, Cs, Mg, Ca, B, Al and U) on the signal of 100 μg l concentrations of several test analytes (V, Cr, Mn, Ni, Co, Cu, Zn, Cd and Pb) has been studied at a single set of operating conditions used for multielement ICP-MS analysis. It appears that some concomitant elements (Na, K, Cs, Mg, Ca) induce an enhancement of the analyte signals while another (Li) does not have any significant effect and others (B, Al, U) cause a suppression. Since in all cases, the change of signal is in the same direction for all the analytes, internal standardization using some background lines was used to try to compensate for these effects. An accurate correction is realized in most cases, with the exception of the heavier elements Cd and Pb which need a separate, heavier internal standard. Overall, the data suggest that a key factor linked to the effects may be the rate of atom-electron collisions: when it increases substantially (as with easily ionized elements), the ionization of the analytes is favored more than their recombination with electrons; but if the concomitant elements form refractory oxides (B, Al and U) that can deposit on the interface, then the collisional rate is lower and the recombination is favored. When no effect is seen, the ionization induced by collisions is balanced by the recombination.
Line loads moving on the surface of an inhomogeneous elastic half space

Treated are line loads travelling with constant speed on the surface of an inhomogeneous elastic half space, the materials considered being such that uncoupled motions can arise. Assuming a quasi static state, solutions are presented for (i) a line force in the plane of the surface, acting in a direction perpendicular to that of its motion (called SH line load), and (ii) a normal line force moving in a direction perpendicular to its length.
Variation in diagnosis and treatment of chronic low back pain by traditional Chinese medicine acupuncturists.

Abstract Objectives: To assess interrater reliability of Traditional Chinese Medicine (TCM) diagnosis and treatment of chronic low back pain. Design: Under a Latin square design, six TCM acupuncturists evaluated the same six patients on the same day. Setting: Northwest Institute of Acupuncture and Oriental Medicine, Seattle, Washington. Interventions: Assessment only. Outcome measures: TCM diagnosis, acupoint prescriptions, auxiliary treatment recommendations. Results: Twenty diagnoses and 65 acupoints were used at least once. The diagnosis of Qi/Blood Stagnation with Kidney Deficiency and the acupoint UB23 were used for every patient by most acupuncturists. However, consistency across acupuncturists regarding diagnostic details and other acupoints was poor. No diagnoses, and only one acupoint, were used preferentially for a subgroup of patients. Some diagnoses and treatment recommendations were dependent more on the practitioner than on the patient. Fine-grained diagnoses and most acupoints were unrelated to either patient or practitioner. Conclusions: TCM diagnoses and treatment recommendations for specific patients with chronic low back pain vary widely across practitioners. Acupuncture clinical trials using an individualized treatment arm may be difficult to replicate or evaluate because of low concordance among acupuncturists. Comparison of individualized treatment with a thoughtfully developed standardized approach is warranted to determine which, if either, is superior.
Inhibition of human parainfluenza virus type 3 infection by novel small molecules

Human parainfluenza virus type 3 (HPIV3) is an important respiratory tract pathogen of infants and children. There are no vaccines or antivirals currently approved for prevention or treatment of HPIV3 infection. Towards developing an antiviral therapy to combat HPIV3 infection, we have established a green fluorescent protein (GFP)-tagged HPIV3 infected-cell assay and used it for screening of a small molecule library obtained from ChemBridge Diver. Two novel small molecules (C5 and C7) which shared structural similarities were identified and their inhibitory effects on HPIV3 were confirmed in CV-1 and human lung epithelium A549 cells by plaque assay, Western blot and Northern blot analyses. C5 and C7 effectively prevented the cytopathic effect in cells infected with HPIV3, achieving IC(50) values of 2.36 microM and 0.08 microM, respectively, for infectious virus production. The inhibition appears to be at the primary transcriptional level of HPIV3 life cycle based on sequential time course test, binding and internalization assays, and finally by a minigenome transcription assay in cells as well as measuring viral transcripts in cells in the presence of anisomycin. Interestingly, vesicular stomatitis virus (VSV), another member of mononegavirales order, was also inhibited by these compounds, whereas poliovirus-a picornavirus was not. Use of these inhibitors has a strong potential to develop novel antiviral agents against this important human pathogen.
A method to overcome computational difficulties in the exterior acoustics problem

When the boundary integral equation method is applied to exterior acoustics problems, singularities occur in the resulting algebraic equations at various frequencies associated with the eigenvalues of an interior problem. These frequencies are referred to as ‘‘forbidden,’’ and various methods have been devised to overcome the computational difficulties presented at these frequencies. The work presented here is an extension to the CHIEF method in that higher derivatives, in addition to the function itself, are constrained to be zero at selected points in the interior domain. Whereas the relative success of either method depends on the quantity and selection of interior points, the SuperCHIEF method requires fewer interior points and is less sensitive to point selection, resulting in improved robustness without a significant increase in computational complexity.
Accident assessment of vehicles on long-span bridges in windy environments

Abstract Currently, there are very few systematic analyses of vehicle performance on bridges in windy environments. There are thus no scientific data to support bridge management in this regard, such as when to close traffic on bridges. This paper presents a framework of vehicle accident analysis model on long-span bridges in windy environments. In the accompanying paper, a three-dimensional analysis of the coupled bridge–vehicle–wind system is developed. Each vehicle is modeled as a combination of several rigid bodies, axle mass blocks, springs, and dampers. Dynamic interaction analysis is then conducted on the vehicle–bridge system to predict the “global” bridge and vehicle dynamic responses without considering accident occurrences. The results of the global bridge–vehicle vibrations serve as the basis for the present accident analysis of the “local” vehicle vibrations. With the global vibrations as inputs of the accident model, the lateral response, yaw response of the vehicle, and the reaction forces of each individual wheel are obtained and the stability condition of the vehicles are analyzed. The vehicle accidents on long-span bridges are then identified with given accident criteria. The developed framework can be used in not only analyzing the vehicle performance on highways and on bridges, but also in predicting useful information for emergency preparedness agencies in developing evacuation plans.
Plastic microchip electrophoresis with analyte velocity modulation. Application to fluorescence background rejection.

Fluorescence background interference from the device is inherent in plastic microchips, particularly with blue or UV excitation. Conventionally, microchip background has been reduced with confocal optics or circumvented with specialized long-wavelength fluorophores. We show that microchip background can be rejected with analyte velocity modulation. In this scheme, the driving voltage is modulated at low frequency, typically in the range of 7−20 Hz. Consequently, migration velocities and analyte signals are modulated at the same frequency. Microchip fluorescence is unmodulated, so that lock-in detection (synchronous demodulation) easily separates the analyte signal from background. The technique does not require a laser source. In our implementation, a blue (485 nm) LED is the light source. Simple optics are used to shape the source and focus it to a spot ∼50 μm in diameter inside a microchip. Photomultiplier detection is employed, and a lock-in amplifier is used to demodulate the signal. Apertures in the ...
Electroconformational coupling for ion transport in an oscillating electric field rectification versus active pumping

Abstract To explain the activation of membrane ATPases by an oscillating electric field, an electroconformational coupling (ECC) model has previously been proposed [T.Y. Tsong and R.D. Astumian, Bioelectrochem. Bioenerg., 15 (1986) 457]. In this model, the ability of a membrane transport system to interact with an electric field is attributed solely to the ATPase: a concomitant charge displacement of the transporter during the ligand translocation step. To emphasize this point, the simulations of the electric field induced cation pumping by Na,K-ATPase have been done by assuming the transported ligand to be a neutral species. However, if the transported ligand is an ion, the effects of rectification must also be taken into account. Here we examine the properties of rectification and active pumping of the ECC model. Any electrically active membrane transport system may be classified into one of the following five categories (Table 1 below): (1) a transporter with gating charge and a neutral ligand, (2) a transporter without gating charge and charged ligand, (3) protein—ligand complexes without gating charge, i.e. the gating charge of the transporter being neutralized by the charge of the ligand, (4) a transporter and a protein—ligand complexes with gating charges of opposite signs, and (5) a transporter with a gating charge and a charged ligand of the same sign. Analysis indicates that in all these cases, there is an active transport and energy can be transduced from an oscillating field to a concentration gradient. In cases (1) and (5), energy can be transduced in both directions, with a theoretical maximum efficiency of 100%. In cases (2), (3), and (4), reverse energy transduction, i.e. conversion of chemical potential energy into electric energy, cannot be achieved. The maximum efficiency of direct energy transduction is 8.7% in cases (2) and (3) and 50% in case (4). The active transport in cases (2), (3) and (4) is mainly due to rectification. In all cases, the active flux depends strongly on the frequency of the field and on the concentration of the ligand, and it displays windows both on the frequency and the concentration axes. The maximum concentration gradient, (A″/A′)max, which can be supported by this mechanism, i.e. the static head, has been calculated. When a four-state transporter is considered, the rate constants and the equilibrium constants can be determined by measuring the position of the windows, fluxes, and static head point by varying the experimental conditions.
Thermal stability of SU-8 fabricated microstructures as a function of photo initiator and exposure doses

SU-8 has been used directly as structural material for MEMS/BioMEMS components as well as optical MEMS components. Although the applications of SU-8 photoresist have widely been presented, the material properties and behavior at elevated temperature have rarely been reported. In this paper, the thermal stability of the SU-8 structures as the function of exposure doses and photo initiator concentration changes has been studied. Differential Scanning Calorimeter (DSC), Thermogravimetric Analyzer (TGA) and Dynamic mechanical analysis (DMA) are employed to study the thermal stabilities of exposed SU-8 microstructures. Mass loss as the function of exposure doses and post-baking time were studied by TGA. The results show that the relative mass loss is inversely proportional to the exposure dose as well as the post-baking time, which also directly affect the thermal stability of SU-8 components. The DSC results reveal that there is a phase change reaction occurs around the temperature of 150°C and is directly related to the photo initiator. The effects of this phase change on the tensile strength and creep behavior of SU-8 fabricated microstructures were also explored using DMA. These results will provide the MEMS researchers and engineers with the usable information in SU-8 applications. At the end, how to optimize SU-8 processing parameters to increase its thermal stability is discussed.
Multiphase materials with lignin: 7. Block copolymers from hydroxypropyl lignin and cellulose triacetate

Abstract Several block copolymers were prepared from hydroxypropyl lignin (HPL) by crosslinking with NCO-terminated cellulose triacetate (CTA) of low degree of polymerization ( DP ). Copolymer films were obtained by solution casting of the uncured mixture, followed by curing. The parameters of investigation were HPL and CTA weight fractions and CTA block size. Morphological and thermal characteristics showed that all films were brittle materials with single T g values and crystallinity even for cellulose blocks of DP 10. Network structure was not found to influence material properties, but crystallinity did in all compositions.
What's Wrong, What's Right with Social Work Supervision

A questionnaire was sent to 1500 social work supervisors and 1500 direct-service supervisees identified from the National Association of Social Workers membership list. Two open-ended questions asked for supervisor's self-perception of their "strengths" and "shortcomings" in supervision. Supervisees were asked to identify similar attributes in their supervisors. Respondents generated 2746 comments on supervisor "strengths and shortcomings." Categorization of responses indicated that practice expertise and relationship skills manifested in the supervisory relationship were among the principal "strengths." Reluctance to exercise managerial authority, hesitancy to advocate for staff with administration and inadequate time devoted to supervision were among the principal "shortcomings."
Batch discovery of recurring rare classes toward identifying anomalous samples

We present a clustering algorithm for discovering rare yet significant recurring classes across a batch of samples in the presence of random effects. We model each sample data by an infinite mixture of Dirichlet-process Gaussian-mixture models (DPMs) with each DPM representing the noisy realization of its corresponding class distribution in a given sample. We introduce dependencies across multiple samples by placing a global Dirichlet process prior over individual DPMs. This hierarchical prior introduces a sharing mechanism across samples and allows for identifying local realizations of classes across samples. We use collapsed Gibbs sampler for inference to recover local DPMs and identify their class associations. We demonstrate the utility of the proposed algorithm, processing a flow cytometry data set containing two extremely rare cell populations, and report results that significantly outperform competing techniques. The source code of the proposed algorithm is available on the web via the link:http://cs.iupui.edu/~dundar/aspire.htm.
Novel enzymatic cyclizations of pyridine nucleotide analogs: Cyclic-GDP-ribose and cyclic-HDP-ribose

Summary The cyclase of Aplysia californica catalyzed an alternative mode of cyclization of nicotinamide guanine dinucleotide (NGD) and nicotinamide hypoxanthine dinucleotide (NHD) to form cyclic-GDP-ribose (cGDPR) and cyclic-HDP-ribose (cHDPR) respectively. In these cyclic nucleotides, the newly formed glycosyl bonds are attached onto the N-7 nitrogen of the purine rings instead of the N-1 nitrogen as in cyclic ADP-ribose (cADPR).
Selenium compound analysis by particle beam/hollow cathode optical emission spectroscopy (PB/HC-OES): monitoring of carbon and hydrogen emission from organoselenium compounds

By virtue of the underlying fundamental process, speciation via atomic spectroscopy methods is only accomplished by inference from empirical formulae. The coupling of particle beam sample introduction and hollow cathode optical emission spectroscopy (PB/HC-OES) is applied here for empirical formula determinations of a group of organoselenium compounds. In this application, the carbon and hydrogen optical emission from the organoselenium compounds was monitored and the analyte element response (C (I) and H (I)) to glow discharge operation conditions was studied. Analytical response curves for integrated C and H emission intensities, as a function of both single analyte (selenomethionine) concentration and the empirical formula of the model compounds, were obtained. In all cases, a variability of less than 10% RSD for triplicate injections of 200 µL samples is observed. The detection limits of 0.16 ppm of selenomethionine (0.05 ppm of elemental C) and 0.034 ppm of selenomethionine (0.0019 ppm of elemental H) were obtained over the concentration range of 0.01–1000 ppm. Within the 100 µL injections, these values equate to absolute masses of 16 ng of selenomethionine (i.e. 5 ng of elemental carbon) and 3.4 ng of selenomethionine (i.e. 0.2 ng of elemental hydrogen). The corresponding detection limits for the selenium content in Se-(methyl)selenocysteine were determined to be 11 ng of elemental Se. The correlation of H (I)/C (I) emission intensity values to the atomic H/C values in different organoselenium compounds demonstrates that the PB/HC-OES system is capable of selenium speciation by means of the determination of empirical formulae.
The International Journal of Emergency Medicine: successes of the first year

When the first call for papers for the International Journal of Emergency Medicine (IJEM) went out in January 2008, all of us believed in the journal, few of us knew how the EM fraternity would respond, and none of us could predict its status one year later. Ayear has now passed, 4 issues down the road, and we are privileged to report on its successes. These have been multi-factorial: a dedicated cadre of peer reviewers, a loyal editorial board, a supportive publishing team, and, perhaps most importantly, a real need for such a journal to exist. We all have been through the anguish as the author of an article awaiting journal reviews. IJEM has striven to ensure a quick turnaround time for the manuscripts received. The journal turnaround time includes several components. The average number of days between the date the manuscript
Consomic rat model systems for physiological genomics

A consomic rat strain is one in which an entire chromosome is introgressed into the isogenic background of another inbred strain using marker-assisted selection. The development and physiological screening of two inbred consomic rat panels on two genetic backgrounds (44 strains) is well underway. Consomic strains enable one to assign traits and quantitative trait loci (QTL) to chromosomes by surveying the panel of strains with substituted chromosomes. They enable the rapid development of congenic strains over a narrow region and enable one to perform F2 linkage studies to positionally locate QTL on a single chromosome with a fixed genetic background. These rodent model systems overcome many of the problems encountered with segregating crosses where even if linkage is found, each individual in the cross is genetically unique and the combination of genes cannot be reproduced or studied in detail. For physiologists, consomics enable studies to be performed in a replicative or longitudinal manner to elucidate in greater detail the sequential expression of genes responsible for the observed phenotypes of these animals. They often provide the best available inbred control strains for physiological comparisons with the parental strains and they enable one to assess the impact of a causal gene region in a genome by allowing comparisons of the effect of replacement of a specific chromosome on a disease susceptible or a resistant genomic background. Consomic rat strains are proving to be a unique scientific resource that can greatly extend our understanding of genes and their role in the regulation of complex function and disease.
Increased sphingosine-1-phosphate improves muscle regeneration in acutely injured mdx mice

Presently, there is no effective treatment for the lethal muscle wasting disease Duchenne muscular dystrophy (DMD). Here we show that increased sphingosine-1-phoshate (S1P) through direct injection or via the administration of the small molecule 2-acetyl-4(5)-tetrahydroxybutyl imidazole (THI), an S1P lyase inhibitor, has beneficial effects in acutely injured dystrophic muscles of mdx mice. We treated mdx mice with and without acute injury and characterized the histopathological and functional effects of increasing S1P levels. We also tested exogenous and direct administration of S1P on mdx muscles to examine the molecular pathways under which S1P promotes regeneration in dystrophic muscles. Short-term treatment with THI significantly increased muscle fiber size and extensor digitorum longus (EDL) muscle specific force in acutely injured mdx limb muscles. In addition, the accumulation of fibrosis and fat deposition, hallmarks of DMD pathology and impaired muscle regeneration, were lower in the injured muscles of THI-treated mdx mice. Furthermore, increased muscle force was observed in uninjured EDL muscles with a longer-term treatment of THI. Such regenerative effects were linked to the response of myogenic cells, since intramuscular injection of S1P increased the number of Myf5 nlacz/+ positive myogenic cells and newly regenerated myofibers in injured mdx muscles. Intramuscular injection of biotinylated-S1P localized to muscle fibers, including newly regenerated fibers, which also stained positive for S1P receptor 1 (S1PR1). Importantly, plasma membrane and perinuclear localization of phosphorylated S1PR1 was observed in regenerating muscle fibers of mdx muscles. Intramuscular increases of S1P levels, S1PR1 and phosphorylated ribosomal protein S6 (P-rpS6), and elevated EDL muscle specific force, suggest S1P promoted the upregulation of anabolic pathways that mediate skeletal muscle mass and function. These data show that S1P is beneficial for muscle regeneration and functional gain in dystrophic mice, and that THI, or other pharmacological agents that raise S1P levels systemically, may be developed into an effective treatment for improving muscle function and reducing the pathology of DMD.
p-Chloroamphetamine formation responsible for long-term depletion of brain serotonin after N-cyclopropyl-p-chloroamphetamine injection in rats.

Abstract After the injection of N-cyclopropyl-p-chloroamphetamine (N-cyclopropyl-PCA) into rats, p-chloroamphetamine (PCA) was identified in brain by high performance liquid chromatography with UV detection and was quantitated by that method and by spectroflurometric analysis involving reaction with fluorescamine. The identity of PCA in brains of rats treated with N-cyclopropyl-PCA was confirmed by mass spectrometry. The peak concentrations of PCA in brain occurred 4 hrs after N-cyclopropyl-PCA injection. Brain concentrations of PCA and of N-cyclopropyl-PCA were measured at 1 or 4 hrs, respectively, after the injection of various doses of PCA or of N-cyclopropyl-PCA into rats. The depletion of brain serotonin and 5-hydroxyindoleacetic acid (5-HIAA) was measured 1 week after injection of those same doses of PCA or N-cyclopropyl-PCA. Comparing peak concentrations of PCA with the degree of depletion of brain serotonin supported the interpretation that PCA formed metabolically accounted for the long-term depletion of brain 5-hydroxyindoles after injection of N-cyclopropyl-PCA in rats.
Strategy for the Use of Affinity Grids to Prepare Non-His-Tagged Macromolecular Complexes for Single-Particle Electron Microscopy

Affinity Grids are electron microscopy (EM) grids with a pre-deposited lipid monolayer containing functionalized nickel-nitrilotriacetic acid lipids. Affinity Grids can be used to prepare His-tagged proteins for single-particle EM from impure solutions or even directly from cell extracts. Here, we introduce the concept of His-tagged adaptor molecules, which eliminate the need for the target protein or complex to be His-tagged. The use of His-tagged protein A as adaptor molecule allows Affinity Grids to be used for the preparation of virtually any protein or complex provided that a specific antibody is available or can be raised against the target protein. The principle is that the Affinity Grid is coated with a specific antibody that is recruited to the grid by His-tagged protein A. The antibody-decorated Affinity Grid can then be used to isolate the target protein directly from a cell extract. We first established this approach by preparing negatively stained specimens of both native ribosomal complexes and ribosomal complexes carrying different purification tags directly from HEK-293T cell extract. We then used the His-tagged protein A/antibody strategy to isolate RNA polymerase II, still bound to native DNA, from HEK-293T cell extract, allowing us to calculate a 25-A-resolution density map by single-particle cryo-EM.
Adaptive compressed sensing — A new class of self-organizing coding models for neuroscience

Sparse coding networks, which utilize unsupervised learning to maximize coding efficiency, have successfully reproduced response properties found in primary visual cortex [1]. However, conventional sparse coding models require that the coding circuit can fully sample the sensory data in a one-to-one fashion, a requirement not supported by experimental data from the thalamo-cortical projection. To relieve these strict wiring requirements, we propose a sparse coding network constructed by introducing synaptic learning in the framework of compressed sensing. We demonstrate a new model that evolves biologically realistic, spatially smooth receptive fields despite the fact that the feedforward connectivity subsamples the input and thus the learning must rely on an impoverished and distorted account of the original visual data. Further, we demonstrate that the model could form a general scheme of cortical communication: it can form meaningful representations in a secondary sensory area, which receives input from the primary sensory area through a “compressing” cortico-cortical projection. Finally, we prove that our model belongs to a new class of sparse coding algorithms in which recurrent connections are essential in forming the spatial receptive fields.
Dynamical breaking of weak interaction symmetries

Abstract A realistic theory of dynamically broken weak interactions not only requires fermions with a new strong interaction at 1 TeV, but also additional gauge couplings which explicitly break quark and lepton chiral symmetries. This “sideways” gauge interaction connects light fermions to the 1 TeV fermions and, very likely, to themselves as well. It is dynamically broken near 100 TeV to a subgroup containing the 1 TeV interactions. This dynamical scheme is subject to definite low- energy tests: (1) Charged and neutral spinless pseudo-Goldstone bosons with mass expected between 10 and 40 GeV; the charged ones are readily detectible in e+e− annihilation. (2) Flavor-changing neutral-current interactions which mediate rare decays at rates not far below present upper limits.
A structural view of the Cedar programming environment

This paper presents an overview of the Cedar programming environment, focusing on its overall structure—that is, the major components of Cedar and the way they are organized. Cedar supports the development of programs written in a single programming language, also called Cedar. Its primary purpose is to increase the productivity of programmers whose activities include experimental programming and the development of prototype software systems for a high-performance personal computer. The paper emphasizes the extent to which the Cedar language, with run-time support, has influenced the organization, flexibility, usefulness, and stability of the Cedar environment. It highlights the novel system features of Cedar, including automatic storage management of dynamically allocated typed values, a run-time type system that provides run-time access to Cedar data type definitions and allows interpretive manipulation of typed values, and a powerful device-independent imaging model that supports the user interface facilities. Using these discussions to set the context, the paper addresses the language and system features and the methodologies used to facilitate the integration of Cedar applications. A comparison of Cedar with other programming environments further identifies areas where Cedar excels and areas where work remains to be done.