cssi/SciSciGPT-SciSciNet huggingface dataset:
Isolation and complementation of nitrogen fixation mutants of the cyanobacterium Anabaena sp. strain PCC 7120.

Abstract Approximately 140 mutants of Anabaena sp. strain PCC 7120 unable to grow aerobically on media lacking fixed nitrogen (Fix-) were isolated after mutagenesis with diethyl sulfate and penicillin enrichment. A large cosmid library of wild-type Anabaena sp. strain PCC 7120 DNA was constructed in a mini-RK-2 shuttle vector, and seven mutants representing several morphologically abnormal heterocyst phenotypes were complemented. One of these mutants, 216, failed to differentiate heterocysts. All of these mutants except 216 reduced acetylene under anaerobic conditions, indicating that they are not defective in nitrogen fixation per se. Several cosmids were isolated from each complemented mutant and in most cases showed similar restriction patterns. Comparisons of the complementing cosmids from mutant 216 and two other phenotypically distinct mutants by restriction enzyme analysis identified a common region. This region, when present in either a cosmid or a 9.5-kb NheI subclone, is capable of efficiently complementing all three mutants. A 2.4-kb subclone of this region complements mutant 216 only.
Development of mesoporous silica-based nanoparticles with controlled release capability for cancer therapy

Nanoparticles that respond to internal and external stimuli to carry out controlled release of anticancer drugs have been developed. In this review, we focus on the development of mesoporous silica based nanoparticles, as this type of materials provides a relatively stable material that is amenable to various chemical modifications. We first provide an overview of various designs employed to construct MSN-based controlled release systems. These systems respond to internal stimuli such as pH, redox state and the presence of biomolecules as well as to external stimuli such as light and magnetic field. They are at a different stage of development; depending on the system, their operation has been demonstrated in aqueous solution, in cancer cells or in animal models. Efforts to develop MSNs with multi-functionality will be discussed. Safety and biodegradation of MSNs, issues that need to be overcome for clinical development of MSNs, will be discussed. Advances in the synthesis of mechanized theranostic nanoparticles open up the possibility to start envisioning future needs for medical equipment.
Editorial overview for this special issue on understanding cognitive development: Approaches from mind and brain

The concept for this special issue emerged in the summer of 2010, when a small group of cognitive scientists—including some authors of papers in this volume—assembled for an informal thought sessio...
Estimates on the vorticity of solutions to the Navier-Stokes equations

We estimate the vorticity of the flow of an incompressible, viscous, three dimensional fluid near the boundary of its container. We obtain a bound that is valid outside a small subset of space-time with special properties.
ARES I Aerodynamic Testing at the NASA Langley Unitary Plan Wind Tunnel

Small-scale force and moment and pressure models based on the outer mold lines of the Ares I design analysis cycle crew launch vehicle were tested in the NASA Langley Research Center Unitary Plan Wind Tunnel from May 2006 to September 2009. The test objectives were to establish supersonic ascent aerodynamic databases and to obtain force and moment, surface pressure, and longitudinal line-load distributions for comparison to computational predictions. Test data were obtained at low through high supersonic Mach numbers for ranges of the Reynolds number, angle of attack, and roll angle. This paper focuses on (1) the sensitivity of the supersonic aerodynamic characteristics to selected protuberances, outer mold line changes, and wind tunnel boundary layer transition techniques, (2) comparisons of experimental data to computational predictions, and (3) data reproducibility. The experimental data obtained in the Unitary Plan Wind Tunnel captured the effects of evolutionary changes to the Ares I crew launch vehicle, exhibited good agreement with predictions, and displayed satisfactory within-test and tunnel-to-tunnel data reproducibility.
Between-word speech errors in conduction aphasia

Abstract Comparisons have been made between the segmental speech errors of conduction aphasics and normal speakers, despite the fact that the aphasic data have involved single-word production and the normal data have involved multi-word production. To provide a more appropriate aphasic database, the sentence repetition of a conduction aphasic (CM) is presented. Errors that resulted from an interaction between the phonemes of two words were examined and compared with past reports of such errors in normal speakers. Comparisons between the errors of CM and normal speakers revealed similarities, as well as differences. The similarities support the notion that, as with normal speakers, CM's word-interaction errors reflect disruption at the stage of phonemic string construction. For example, the errors of both CM and normal speakers usually involve the interaction of single segments of words from major lexical categories. However, differences exist in the way that such errors are constrained. For example, CM's ...
Growth inhibition in amphibian larvae by 4-amino pteroyl-glutamic acid (aminopterin).

A NUMBER of workers have demonstrated the inhibition of growth in the rat and mouse1,2, bacteria3–5, and in the chick6–8 by means of folic acid antagonists. Seeger et al.5 have shown that 4-amino pteroyl glutamic acid is a powerful antagonist of folic acid by the Streptococcus faecalis R. test, and its toxicity in mammals has been well established. Karnofsky et al.7 demonstrated quite conclusively that 4-amino pteroyl glutamic acid, as an analogue of folic acid, has the ability to inhibit growth in the chick, and the question arose as to whether this reaction could be found in a cold-blooded vertebrate as well. In this preliminary report, the growth inhibition of amphibian larvae by 4-amino pteroyl glutamic acid is indicated, particularly in the growth phases in the middle and late larvae. Studies on inhibition in early development, effects on embryo-genesis, and possible reversal effects are to be presented elsewhere at a later date.
Autonomic restoration of electrical conductivity using polymer-stabilized carbon nanotube and graphene microcapsules

We report the use of microcapsules containing suspensions of polymer-stabilized carbon nanotubes and/or graphene flakes for the autonomic restoration of conductivity in fractured gold lines. Multilayered samples were prepared in which microcapsules were embedded in layers of epoxy above and below a glass slide patterned with gold lines. Upon sample fracture, conductivity was lost as a crack formed in the gold line. Simultaneous release of carbon nanotubes and/or graphene suspensions from capsule cores restored conductivity in minutes. We suggest a healing mechanism in which the released carbon nanomaterials bridge gaps in the gold lines.
Influence of Adsorption Site and Wavelength on the Photodesorption of NO from the (Fe,Cr)3O4(111) Mixed Oxide Surface

The photochemical properties of nitric oxide on a mixed oxide single crystal surface was examined in ultrahigh vacuum (UHV) using temperature programmed desorption (TPD), photon stimulated desorption (PSD) and low energy electron diffraction (LEED). The mixed oxide was a 75% Fe and 25% Cr corundum (0001) oxide film prepared on an α-Al2O3(0001) crystal, however its surface became terminated with a magnetite-like (111) structure after sputter/anneal cleaning, leading to a surface designated of (Fe,Cr)3O4(111). TPD of NO from the (Fe,Cr)3O4(111) surface revealed three chemisorbed states at 220, ~315 and 370 K assigned to NO binding at Fe3+, Cr3+ and Fe2+ sites, respectively. No significant thermal chemistry of NO was detected. NO photodesorption, the primary photochemical pathway in UHV, was sensitive to the adsorption site, with rates at the three adsorption sites following the trend: Fe3+ > Fe2+ > Cr3+. Multiexponential rate behavior seen in the overall NO PSD spectra was linked directly to site heterogeneity being manifested as a convolution of the individual NO photodesorption rates at the three types of surface sites. The photodesorption rate with UV light (365 nm) was ~10 times greater than that in the visible, but the per-photon rates across the visible spectrum (from 460 tomore » 630 nm) were independent of the wavelength, which is suggestive of localized photon absorption at the adsorption site. Results in this study demonstrate that the adsorption site plays a critical role in determining photochemical rates on complex oxide surfaces. This work was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multi-program national laboratory operated for DOE by Battelle. The research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.« less
Production of 30-fs pulses tunable throughout the visible spectral region by a new technique in optical parametric amplification.

A multipass optical parametric amplifier is pumped by a 250-kHz microjoule-level Ti:sapphire regenerative amplifier system. Tuning each pass of the amplifier to provide gain for slightly different spectral regions of a white-light continuum source produces broadband pulses that may be compressed to less than 30 fs.
Hypotensive hemorrhage elevates corticotropin-releasing hormone messenger ribonucleic acid (mRNA) but not vasopressin mRNA in the rat hypothalamus.

We examined the effect of acute hypotensive hemorrhage on corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) messenger RNAs (mRNAs) in neurons of the rat hypothalamus. Sprague-Dawley male rats were cannulated (femoral artery and vein) and received a 15 ml/kg.3 min hemorrhage on the morning of the fourth day. Time controls received no hemorrhage. After light halothane anesthesia, the rats were decapitated at 1 or 4 h (six to nine rats per group). The hypothalami were removed, frozen, and sectioned at 12 microns. In situ hybridization was performed using two 48-base oligodeoxynucleotide probes for CRH and AVP message, respectively. Hemorrhage led to a fall in arterial blood pressure and heart rate that recovered by 1 h. Plasma ACTH, corticosterone, and AVP were elevated 20, 60, and 90 min after hemorrhage, but returned to near control levels by 4 h. CRH mRNA was significantly elevated 1 and 4 h after hemorrhage, as compared to time controls, in parvocellular neurons of the paraventricular ...
Wideband chelate lasers in the visible

Abstract Broadband visible lasing has been demonstrated in several metal chelate compounds. Results which have been obtained suggest that these compounds are worthy of further investigation as to their applications as liquid lasers.
Paediatric labelling requirements. Implications for pharmacokinetic studies.

The US Food and Drug Administration (FDA) has proposed new labelling regulations that describe alternative approaches for providing additional information to support labelling a drug, already approved for use in adults, for use in children. Therefore, the study of drugs in paediatric populations may now be encouraged. Paediatric pharmacokinetic studies are an important part of these trials. This action by the FDA may help resolve the ethical and technological concerns about the performance of clinical trials in children, and may render paediatric clinical trials more feasible. Most investigations in children are opportunistic in nature and their design is often constrained by a requisite noninvasive approach. Appropriately applied population-based techniques for both pharmacokinetic and pharmacodynamic data analysis may represent the most robust approach for generating a sufficiently large and accurate database for the use of new or old drugs in paediatric patients. Accordingly, this information, which is crucial for paediatric labelling of any drug product, must be obtained in infants and children if we are to truly individualise therapy for paediatric patients. The funding of 6 Pediatric Pharmacology Research Units by the US National Institutes of Health, and guidelines for application of pharmacokinetic methods to children may further contribute to the performance of paediatric clinical trials.
CONVULSIVE INTERACTIONS OF PROMETHAZINE, MEPERIDINE AND LIDOCAINE.

Abstract Reports occurring relative to the convulsive toxic reactions in humans of promethazine, meperidine and lidocaine prompted this study of the convulsant relationships of these agents, alone or as combinations, injected intraperitoneally in mice. The doses were converted from mg/kg to millimoles/kg (mM/kg) and log-dose response curves were plotted to determine the CD50. Promethazine and meperidine were equipotent in producing convulsions with the CD50 of each being 0.37 mM/kg; lidocaine was significantly different with the CD50 being 0.28 mM/kg. When promethazine and meperidine were combined, the CD50 resulted at a combined dose of 0.28 mM suggesting a synergistic action. When promethazine or meperidine, or both, at doses totalling 0.15 mM/kg were combined with lidocaine, the CD50 occurred at 0.20 mM/kg of lidocaine, suggesting a potentiation of the action of lidocaine. The drugs in combination also resulted in a significant change in the slopes of the doseresponse curves when compared to the drugs alone. Since the toxic effects of the agents in mice appear similar to those effects found in the humans, the study suggested a critical re-evaluation of this drug combination.
Local Inhibition of Tissue Factor Reduces the Thrombogenicity of Disrupted Human Atherosclerotic Plaques Effects of Tissue Factor Pathway Inhibitor on Plaque Thrombogenicity Under Flow Conditions

Background—Plaque disruption and subsequent thrombus formation lead to acute coronary syndromes and progression of atherosclerotic disease. Tissue factor (TF) appears to mediate plaque thrombogenicity. Tissue factor pathway inhibitor (TFPI) is the major physiological inhibitor of TF. This study analyzes the role of TF on thrombogenicity of disrupted human atherosclerotic plaques and the therapeutic possibilities of its specific inhibition. Methods and Results—Human atherosclerotic and normal arterial segments were exposed to heparinized blood at flow conditions modeling medium-grade coronary stenosis in the Badimon perfusion chamber. The antithrombotic effects of the specific inhibition of plaque TF was assessed by reduction in the deposition of radiolabeled platelets and fibrin(ogen) and immunohistochemical analysis of perfused arteries. TF activity was inhibited by both recombinant TFPI and a polyclonal antibody against human TF. Human lipid-rich plaques were more thrombogenic than less advanced atheros...
Host immune responses to rhinovirus: Mechanisms in asthma

Viral respiratory infections can have a profound effect on many aspects of asthma including its inception, exacerbations, and, possibly, severity. Of the many viral respiratory infections that influence asthma, the common cold virus, rhinovirus, has emerged as the most frequent illness associated with exacerbations and other aspects of asthma. The mechanisms by which rhinovirus influences asthma are not fully established, but current evidence indicates that the immune response to this virus is critical in this process. Many airway cell types are involved in the immune response to rhinovirus, but most important are respiratory epithelial cells and possibly macrophages. Infection of epithelial cells generates a variety of proinflammatory mediators to attract inflammatory cells to the airway with a subsequent worsening of underlying disease. Furthermore, there is evidence that the epithelial airway antiviral response to rhinovirus may be defective in asthma. Therefore, understanding the immune response to rhinovirus is a key step in defining mechanisms of asthma, exacerbations, and, perhaps most importantly, improved treatment.
Current perspectives in Alzheimer's Disease

Alzheimer's disease (AD) is a growing public health crisis. It is an age-related disorder, with prevalence increasing in older populations. This is a particularly urgent problem in light of the fact that the elderly population of the United States and the world is growing rapidly. By the year 2030, one person in every five will be over the age of 65, and there will be 8.4 million individuals aged 85 or older. The frequency of dementia, of which AD is the most common form, doubles every 5 years after the age of 60, rising from a prevalence …
Anion symmetry and the separability of structural parameters for tetramethyltetraselenafulvalenium salts, (TMTSF)2X

Abstract Empirical correlations of various structural parameters for a series of (TMTSF)2X salts have been explored utilizing a van der Waals-like estimate for the radius of the counterion X. Included amongst the parameters studied are: (a) the lengths of the transverse cell constants c and b; (b) the interdonor Se .. Se contact distances; (c) the alternate separation between molecular centers of mass along the columnar stack of donors (a); and (d) the symmetry and strength of the anion coupling to its donor-dominated structural cavity. The notable result is that independent correlations are found for salts containing centrosymmetric and non-centrosymmetric anions.
Osteoarthritis: Is viscosupplementation really so unsafe for knee OA?

The latest in a series of meta-analyses of trials assessing viscosupplementation for knee osteoarthritis is the first to raise concerns about its safety. Questions remain, however, regarding the methodological rigour with which the serious adverse events were analyzed, and the biological plausibility of the events reported.
The pathogenesis of Dupuytren's contracture: Contractile mechanisms of the myofibroblasts

The role of myofibroblasts in the pathogenesis of Dupuytren's contracture was investigated by light and electron microscopic histochemical methods. Dupuytren's myofibroblasts contain an intracellular contractile mechanism that is driven by the dephosphorylation of adenosine triphosphate. Our study of calcium adenosinetriphosphatase (ATPase) activities verifies that the site of this energy system is on the myofilaments of the myofibroblasts. The degree of ATPase activity, as determined by cell counts, appeared to correlate with the residual contracture as predicted by the Legge and McFarlane Outcome Standard Formula. Further, alcian blue staining on the ultrastructural level indicates that the myofibroblasts are associated with each other and with surrounding collagen by a glycosaminoglycan matrix 300 to 1000 A thick. Collagen fibrils are attached by a similar matrix comprised of 100 A thick fibrils. The dynamic cellular architecture of the multiple adjacent myofibroblasts with their connections to surrounding collagen may be partially responsible for the residual clinical deformities seen in this disease.
Measuring association populations using the Encyclopedia of Associations: Evidence from the field of labor unions ☆

Abstract Identifying populations of organizations has been a significant methodological challenge for scholars interested in examining various organizational dynamics. A common solution has been to rely upon a prior list or database of organizations. One such database on voluntary national organizations is the Encyclopedia of Associations (EA), a standard tool for sociologists and political scientists interested in associations. This paper compares coverage of labor unions as listed in the EA with information on the same universe of organizations taken from the US Department of Labor’s Office of Labor-Management Standards (OLMS). Results indicate that 103 of 135 (76%) of unions listed in the DOL were also listed in the EA. Among unions with more than 5000 members, EA coverage was 91%. Coverage rose to 95% among those unions with more than 10,000 members. Finally, two measures of financial size show the vast majority of unions with either receipts or net assets greater than $1,000,000 are included in the EA. The EA is therefore quite complete in coverage overall and appears to be nearly universal in its coverage of unions above even quite modest thresholds of organizational size and resources.
Effect of reinforcement size and matrix microstructure on the fracture properties of an aluminum metal matrix composite

Abstract The effects of systematic changes in reinforcement size and matrix microstructure on the crack initiation and growth toughness of a 7091 aluminum alloy reinforced with SiC particulates were studied. It is shown that changes in matrix microstructure have a significant effect on both initiation and growth toughness. The effect of reinforcement size on these properties is far less marked. These observations have been related to local microstructural parameters and the nature of the distribution of the reinforcement.
Targeting the hypoxia-adenosinergic signaling pathway to improve the adoptive immunotherapy of cancer.

The recent approval by the FDA of cancer vaccines and drugs that blockade immunological negative regulators has further enhanced interest in promising approaches of the immunotherapy of cancer. However, the disappointingly short life extension has also underscored the need to better understand the mechanisms that prevent tumor rejection and survival even after the blockade of immunological negative regulators. Here, we describe the implications of the “metabolism-based” immunosuppressive mechanism, where the local tissue hypoxia-driven accumulation of extracellular adenosine triggers suppression via A2 adenosine receptors on the surface of activated immune cells. This molecular pathway is of critical importance in mechanisms of immunosuppression in inflamed and cancerous tissue microenvironments. The protection of tumors by tumor-generated extracellular adenosine and A2 adenosine receptors could be the misguided application of the normal tissue-protecting mechanism that limits excessive collateral damage to vital organs during the anti-pathogen immune response. The overview of the current state of the art regarding the immunosuppressive effects of extracellular adenosine is followed by a historical perspective of studies focused on the elucidation of the physiological negative regulators that protect tissues of vital organs from excessive collateral damage, but, as a trade-off, may also weaken the anti-pathogen effector functions and negate the attempts of anti-tumor immune cells to destroy cancerous cells.
Characteristics of medicated and unmedicated microglobules recovered from complex coacervates of gelatin-acacia.

Abstract Medicated and unmedicated microglobules prepared from complex coacervates of Type A gelatin and acacia were recovered as water-insoluble powders consisting of discrete units, which were spontaneously revertible to highly disperse systems when suspended in water or physiological electrolyte solutions. Spherical microglobules containing up to 15% (w/w) sulfamerazine had a nominal diameter of 30 pm in aqueous suspension. Larger but irregularly shaped products containing up to 45% (w/w) sulfamerazine were also recovered. The relationships of the weight of sulfamerazine added per coacervate batch to weight yield and percent (w/w) included sulfamerazine of the microglobules were both linear.
Vocal Fold Epithelial Barrier in Health and Injury: A Research Review

Purpose Vocal fold epithelium is composed of layers of individual epithelial cells joined by junctional complexes constituting a unique interface with the external environment. This barrier provide...
Magnetic resonance imaging of bone and soft tissue tumors: early experience in 31 patients compared with computed tomography

In 31 patients with 21 soft tissue and 10 bone tumors, magnetic resonance imaging (MRI) and computed tomography (CT) were equally effective in delineating the margins of most soft tissue tumors, and the margins of bone tumors from fat and adjacent normal bone. However, MRI was superior to CT in delineating bone tumors from adjacent muscle, and in showing the relationships to bone of the deep margins of some soft tissue tumors. This was true because the quality of CT images around thick cortical bone often was severely degraded by streak artifact, which does not occur in MRI. Excellent anatomic detail was achieved on MRI by spin echo pulse sequences with short repetition times. Bone tumors were delineated best by spin echo 1000/30 images, and soft tissue tumors by spin echo 1000/30 or inversion recovery images.
PROTON-PROTON SCATTERING PHASE SHIFTS AT 150 Mev

The results of a phase shift analysis of proton-proton scattering data at 150 Mev are reported. The Harvard cross section, polarization, and depolarization data were used in fitting with phase shifts up to Fwaves. (B.O.G.)
An improved synthesis of 2,4,8,10-tetroxaspiro /5.5/ undecane /pentaerythritol diformal/

It is found that high yields of pentaerythritol diformal can be prepared in less than 10 minutes by heating a stirred mixture of pentaerythritol with a slight excess of paraformaldehyde up to about 120 C in the presence of catalic amounts of acid, but without any solvents or with only a small amount of water. The reaction was carried out in two stages: first by preparing the monoformal with a molar equivalent of paraformaldehyde in about five minutes, and then, after cooling to about 70 C, adding the remainder of paraformaldehyde in 1% excess, and heating to about 120 C for a total heating time of 10 minutes
Simulating the vapour phase air/water exchange of p,p′-DDE, p,p′-DDT, lindane, and 2,3,7,8-tetrachlorodibenzodioxin

AbstractUncertainties in our understanding of gaseous air/water exchange have emerged as major sources of concern in efforts to construct global and regional mass balances of both the green house gas carbon dioxide and semi-volatile persistent, bioaccumulative and toxic chemicals. Hoff et al. (1996) suggested that these uncertainties result from a lack of understanding of the overall gaseous air/water mass transport process as well as imprecision in our ability to perform the necessary physicochemical property measurements of the gaseous species of interest. In this work, nine low to intermediate wind speed-dependent mass transport models were evaluated as to their suitability for simulating air/water gaseous exchange of 2,3,7,8-TCDD, p,p′-DDT, p,p′-DDE and lindane. In addition, two physicochemical property estimation procedures were examined over an environmental temperature range of 0 to 40°C and compared with observations reported elsewhere in the literature. Findings from the work included: (1) the ga...
The hunt for mechanisms of circadian timing in the eye of Aplysia.

The goals of our research are to understand how circadian oscillations in the eye of Aplysia califomica are generated and how entraining agents regulate these oscillations. These goals require identification of the molecular components of the oscillator and entrainment pathways as well as elucidation of the biochemical processes by which these components interact with one another. Our experimental strategy entails tracing environmental information along an entrainment pathway until the last component of the pathway is reached. The isolated eye of Aplysia exhibits a circadian rhythm of optic nerve impulses. This rhythm is regulated by at least two entrainment pathways. A photic pathway entrains the rhythm to light-dark cycles and an efferent serotonergic pathway relays neural information from the CNS to the oscillator. Phase shifting by light appears to involve an increase in the levels of cGMP, depolarization, and protein synthesis. Phase shifting by serotonin appears to involve an increase in the levels ...
Deposition of metallic colloids under sub-cooled nucleate boiling

Abstract Heterogeneous nucleate boiling causes the deposition of colloidal particles and governs the growth rate of porous deposit layers on heating surfaces when dilute metallic colloidal suspensions are present in aqueous medium. Post-experimental analysis reveals that these deposits are found in the form of spots of variable thickness around the bubble nucleation site. It is shown here that thickness of these spots and deposit amount is directly related to evaporation rate which is dependent on heating wall temperature and fluid temperature. The experimental observations suggest that the deposition occurs around the contact line of bubble and extends underneath area of bubble micro-layer. Rate of transportation of particles to the wall is directly related to frequency of bubble nucleation and departure diameter of departing bubbles. These transported particles deposit onto the heating surface with an attachment probability, which is modeled here as a function of colloid–surface interaction potential. A model of deposition rate has been developed on the basis of evaporative flux E q ″, attachment probability p att and bulk concentration of colloidal particles C 0 . This model provides qualitative explanation for experimental results and suggests that deposition flux has linear dependence on the quantity p att C 0 E q ″.
Condensational growth of a spherical droplet: Free molecular limit

Abstract Previously reported variational results on the problem of condensation onto a spherical droplet are studied in the free molecular limit. The Mellin transform is used to evaluate certain integrals, and it is noted that the derivative of the variational expression for the condensation rate is quite erroneous. The need for improved trial functions is pointed out.
Growth factors and beta cell replication

Recent studies have demonstrated that human islet allograft transplantation can be a successful therapeutic option in the treatment of patients with Type I diabetes. However, this impressive recent advance is accompanied by a very important constraint. There is a critical paucity of pancreatic islets or pancreatic beta cells for islet transplantation to become a large-scale therapeutic option in patients with diabetes. This has prompted many laboratories around the world to invigorate their efforts in finding ways for increasing the availability of beta cells or beta cell surrogates that potentially could be transplanted into patients with diabetes. The number of studies analyzing the mechanisms that govern beta cell proliferation and growth in physiological and pathological conditions has increased exponentially during the last decade. These studies exploring the role of growth factors, intracellular signaling molecules and cell cycle regulators constitute the substrate for future strategies aimed at expanding human beta cells in vitro and/or in vivo after transplantation. In this review, we describe the current knowledge on the effects of several beta cell growth factors that have been shown to increase beta cell proliferation and expand beta cell mass in vitro and/or in vivo and that they could be potentially deployed in an effort to increase the number of patients transplanted with islets. Furthermore, we also analyze in this review recent studies deciphering the relevance of these specific islet growth factors as physiological and pathophysiological regulators of beta cell proliferation and islet growth.
We Want Yer, McKinley’: Epideictic Rhetoric in Songs from the 1896 Presidential Campaign

Abstract The 1896 presidential campaign included, among many other campaign techniques, a large number of songs that praised and condemned the opposing candidates, William McKinley and William Jennings Bryan. The campaign songs, whose likely purpose was to inspire the candidates’ followers, were epideictic in tone and spirit. By presenting a rhetoric that paralleled epideictic speeches, the songs enabled the opposing candidates themselves to uphold a sense of their own decorum. The songs used values as rhetorical devices; however, the songs ‘purpose was to gain a practical political end rather than to uphold moral principles.
Proton pump inhibitors in the treatment of gastro-oesophageal reflux disease.

Gastro-oesophageal reflux disease (GERD) is the most common peptic acid disease in the western world and is the commonest indication for acid suppression therapy. Major advances have been made over...
Phase-dependent stimulation effects on bursting activity in a neural network cortical simulation

Summary Purpose A neural network simulation with realistic cortical architecture has been used to study synchronized bursting as a seizure representation. This model has the property that bursting epochs arise and cease spontaneously, and bursting epochs can be induced by external stimulation. We have used this simulation to study the time–frequency properties of the evolving bursting activity, as well as effects due to network stimulation. Methods The model represents a cortical region of 1.6mm×1.6mm, and includes seven neuron classes organized by cortical layer, inhibitory or excitatory properties, and electrophysiological characteristics. There are a total of 65,536 modeled single compartment neurons that operate according to a version of Hodgkin–Huxley dynamics. The intercellular wiring is based on histological studies and our previous modeling efforts. Results The bursting phase is characterized by a flat frequency spectrum. Stimulation pulses are applied to this modeled network, with an electric field provided by a 1mm radius circular electrode represented mathematically in the simulation. A phase dependence to the post-stimulation quiescence is demonstrated, with local relative maxima in efficacy occurring before or during the network depolarization phase in the underlying activity. Brief periods of network insensitivity to stimulation are also demonstrated. The phase dependence was irregular and did not reach statistical significance when averaged over the full 2.5s of simulated bursting investigated. This result provides comparison with previous in vivo studies which have also demonstrated increased efficacy of stimulation when pulses are applied at the peak of the local field potential during cortical after discharges. The network bursting is synchronous when comparing the different neuron classes represented up to an uncertainty of 10ms. Studies performed with an excitatory chandelier cell component demonstrated increased synchronous bursting in the model, as predicted from experimental work. Conclusions This large-scale multi-neuron neural network simulation reproduces many aspects of evolving cortical bursting behavior as well as the timing-dependent effects of electrical stimulation on that bursting.
Flexible Controller Design and Its Application for Concurrent Execution of Buffer Centric Dataflows

This paper presents a flexible controller structure for concurrent processing of memory centric coarse grain data flows. We propose a design flow based on block level pipelining where concurrency among processing blocks is fully maintained. The controller is dynamically reconfigurable to support dynamic data-flow structure changes by localizing control signals. The proposed control design method isolates controllers and processing logics such that system integration is simplified while controllers are locally configured from orthogonal global information. The controller also supports interfacing with external processors for asynchronous processing. The controller for heterogeneous processing blocks is synthesized and verified using Verilog and SystemC on FPGA. We present an example demonstrating the effectiveness of the controllers where dynamic reconfiguration of the execution is feasible.
Efficient in vitro regeneration of Leucaena leucocephala using immature zygotic embryos as explants

A method for efficient in vitro regeneration of Leucaena leucocephala cv. K636 was developed using immature zygotic embryos as the explant. Multiple shoot induction was achieved by culturing the explants on half-strength Murashige and Skoog (MS) medium supplemented with thidiazuron (TDZ) (0.03 to 1.5 μM). The maximum number of shoots per explants was achieved in 0.26 μM TDZ-supplemented media. TDZ concentration significantly influenced the induction of multiple shoots as well as the shoot-length. TDZ at 0.35 μM or higher concentrations resulted in abnormal stunted shoots. Full-strength MS media devoid of any plant growth regulator were used for shoot elongation. In vitro root induction was achieved in half-strength MS media supplemented either with 0.54 μM 1-naphthaleneacetic acid (NAA) or with 14.76 μM indole-3-butyric acid (IBA) in combination with 0.23 μM kinetin (Kn). Media supplemented with 14.76 μM IBA in combination with 0.23 μM Kn induced twofold–threefold more roots than media supplemented with 0.54 μM NAA. However, the average root length was lower in 14.76 μM IBA in combination with 0.23 μM Kn than in 0.54 μM NAA. Regenerated plants were maintained under normal condition after hardening. Plants, which were rooted on media supplemented with 14.76 μM IBA in combination with 0.23 μM Kn showed higher survival rate during hardening than those rooted on 0.54 μM NAA supplemented media.
Notes on the wire: ballads, biases, and borders of performance journalism

Performance plays a lead role in the story of journalism. From the speeches of town criers to the spectacles of television comedians, the news has always relied on performers. Media scholars, howev...
Thermodynamics of the helix-coil transition in polypeptides in mixed organic solvents: the influence of inert solvent and side chain.

The thermally induced coil–helix transition of poly(γ-benzyl-L-glutamate) (PBLG) and poly(γ-methyl-L-glutamate) (PMLG) in binary solvent mixtures was investigated by calorimetric and optical rotatory dispersion (ORD) measurements. Dichloroacetic acid was the common active solvent, and the inert solvent was one of the chlorinated hydrocarbons, such as chloroform, 1,3-dichloropropane, 1-chlorobutane, or 1-chlorooctane. The thermodynamic parameters characterizing the intramolecular polypeptide and polypeptide–solvent interactions were calculated using the Karasz and Gajnos theoretical model [(1973) J. Phys. Chem.77, 1139–1145]. It was found that the enthalpy (ΔH1) and entropy (ΔS1) of helix stabilization in the absence of the active solvent depend on the inert solvent, but only in the case of PBLG. This is explained by the additional helix stabilization achieved by the stacking of the benzyl groups. The stacking is more pronounced in less polar chlorinated hydrocarbons with longer aliphatic chains. The results obtained indicate that the maximum helix stability is reached in chlorinated hydrocarbons with 12 C atoms. In the case PMLG, with an aliphatic ester side group, ΔH1 and ΔS1 are independent of the inert solvent. The ORD measurements were used to determine the maximum fraction of helicity attained at constant solvent composition and the transition temperature, Tc, at the point where fH = 0.5. It was found that, for the same solvent composition, Tc was higher than the temperature of the midpoint of the calorimetric peak. This is explained by the fact that the maximum fraction of helicity is less than unity. The finite transition width was taken into account by calculating the phase boundaries for different fractions of helicity using the value of σ estimated from the calorimetric and van't Hoff enthalpies in the usual manner.
Pulsatile Flow in a Straight Circular Pipe with Reabsorption across the Wall

Velocity-, stress- und pressure distribution has been investigated for the flow of a Newtonian liquid in a circular cylindrical tube with reabsorption across the wall. For constant reabsorption the nonlinear steady flow case has been treated for small cross flow Reynoldsnumbers, while for pulsatile flow the flow behavior is presented for constant and exponentially decaying reabsorption across the wall.
Marketing extends beyond humans

Abstract This comment seeks to answer the following question. Is marketing – as most marketing textbooks define the term – something that is limited to humans, or do other non-human species also engage in marketing? To answer this question this comment reviews literature on animal behavior which suggests that at least some non-human animals do engage in exchange processes in order to mutually satisfy needs and wants. This comment therefore concludes that marketing is an activity that extends beyond humans to other members of the animal kingdom.
A large-volume detector capable of charged-particle tracking

We discuss a new scheme to measure charged particle tracks in a large-volume detector. Such detectors are needed for the study of neutrino-induced reactions. The proposed detector consists of arrays of fluorescent fibers submersed in a tank of liquid scintillator. Analysis of the distribution of the light collected by fibers near a charged-particle track can be used to reconstruct the parameters of the track. We show that the results obtained with a simple prototype detector demonstrate that the proposed scheme is feasible.
Common Variable Hypogammaglobulinemia Complicated by an Unusual T-Suppressor/Cytotoxic Cell Lymphoma

A patient with common variable hypogammaglobulinemia (CVH) who presented with recurrent sinopulmonary infections, nodular lymphoid hyperplasia of the small bowel, and intestinal giardiasis was studied. A diffuse lymphocytic lymphoma with small bowel, skin, and hepatic involvement subsequently developed in the patient. Light microscopy of the tumor revealed tissue infiltration with mononuclear cells having the morphologic features of T-lymphocytes. The malignant lymphocytes had characteristics of T-suppressor/cytotoxic cells as established by the absence of surface immunoglobulin and Leu 3 surface markers, and the presence of OKT3 and OKT8 surface markers. Peripheral blood lymphocyte studies revealed an increased number of T-suppressor cells, a reversal of the helper-suppressor ratio, and a generalized state of hyporesponsiveness to mitogen and antigen stimulation. No evidence of retroviral reverse transcriptase activity was detected in cultures of peripheral blood lymphocytes. The association between CVH and a lymphoma composed of cells with T-suppressor/cytotoxic surface markers has not been previously reported. The postulated role of T-suppressor cells in the failure of immunoglobulin synthesis in some forms of CVH suggests that the finding of a T-suppressor/cytotoxic cell lymphoma complicating CVH may be more than fortuitous.
Update on pediatric extracranial vascular anomalies of the head and neck.

Purpose Vascular anomalies most frequently present at birth or in early childhood, and the craniofacial region is the most common site of involvement. A long history of misleading nomenclature born of confusion about the presentation and natural history of various vascular anomalies has made appropriate diagnosis difficult. The present article emphasizes the importance of clarity of nomenclature for proper diagnosis, both clinically and radiographically, to guide appropriate therapy. In addition, updates on clinical concepts, imaging, and treatment strategies will be discussed. Pediatric vascular anomalies can be divided into two broad categories: vascular tumors and vascular malformations. This biologic classification is based on differences in natural history, cellular turnover, and histology. An updated classification was introduced in 1996 by the International Society for the Study of Vascular Anomalies (ISSVA) to include infantile hemangioma variants, other benign vascular tumors, and combined lesions. Widespread confusion propagated throughout the literature and in clinical practice stems from the continued improper use of many of the terms used to describe vascular tumors and malformations ignoring their pathophysiology. This leads to errors in diagnosis and the dissemination of misinformation to patients and clinicians. Certain terms should be abandoned for more appropriate terms. The clinical presentation usually identifies what general type of vascular anomaly is present, either vascular tumor or vascular malformation. Imaging provides crucial information about the initial diagnosis and aids in follow-up.
TIMELINESWikipedia: the happy accident

Joseph Reagle's work on Wikipedia and its predecessors opened my eyes to a fascinating history. I'm delighted he has provided this account of the origin of the most interesting digital object since the Web itself. ---Jonathan Grudin
Enhancement of apparent contrast in flashed sinusoidal gratings.

Abstract The apparent contrast of suprathreshold grating targets was measured as a function of their spatial frequency and exposure duration. For targets of low spatial frequency, apparent contrast reaches a maximum at exposure durations of 80–100 msec relative to its value at shorter and longer durations. Contrast-duration curves thus resemble brightness-duration curves when the Broca-Sulzer effect is present. For gratings of higher spatial frequency, apparent contrast increases monotonically with duration. Thus, temporal contrast enhancement occurs only for low spatial frequency targets. The enhancement effect occurs foveally as well as for peripherally viewed targets, but it is abolished by decreasing the vertical extent of the grating.
Developing and validating a framework for integrating systems and software engineering

As illustrated in the harmonization of ISO 15288 and ISO 12207, the disciplines of systems engineering and software engineering share many processes, methods, and concerns. In most systems of interest, software now provides a significant majority of functionality and increasingly is a significant component in determining non-functional attributes. Failures in system acquisition and implementation are often attributed to systems and/or software engineering shortfalls. The need to apply systems engineering to software design and development, as well as the need to incorporate software engineering concepts into systems engineering decisions, implies that a closer relationship between the two disciplines is appropriate. This paper states a clear rationale for integrating the two disciplines, defines a framework that establishes a vocabulary for discussing integration, and presents initial findings in using that framework to describe systems and software integration in ongoing defence programs.
Nested Miller compensation using current buffers for multi-stage amplifiers

Firstly, a literature review of existing nested Miller compensation (NMC) schemes for low-voltage multi-stage amplifiers is made. Secondly, a novel nested Miller compensation using two current buffers (NMCCB) in the feedback network is introduced. As opposed to previous NMC schemes, this scheme uses a non-inverting gain stage for the first stage and inverting gain stages for both the second and third stages. An inverting current buffer is utilized for the first time whereas previous NMC feedback networks utilized a positive current buffer. In conventional NMC, the major limitation is bandwidth since inner compensation capacitance loads the output node. In the proposed scheme, the two current buffers in the feedback network create two LHP zeros, cancelling one of the non-dominant poles and extending the bandwidth. Detailed small-signal modeling and analysis of the NMCCB compensation network is presented, demonstrating the effectiveness of this strategy.