cssi/SciSciGPT-SciSciNet huggingface dataset:
Majorana zero modes in one-dimensional quantum wires without long-ranged superconducting order

We show that long-ranged superconducting order is not necessary to guarantee the existence of Majorana fermion zero modes at the ends of a quantum wire. We formulate a concrete model, which applies, for instance, to a semiconducting quantum wire with strong spin-orbit coupling and Zeeman splitting coupled to a wire with algebraically decaying superconducting fluctuations. We solve this model by bosonization and show that it supports Majorana fermion zero modes. We show that electron backscattering in the superconducting wire, which is caused by potential variations at the Fermi wave vector, generates quantum phase slips that cause a splitting of the topological degeneracy, which decays as a power law of the length of the superconducting wire. The power is proportional to the number of channels in the superconducting wire. Other perturbations give contributions to the splitting that decay exponentially with the length of either the superconducting or semiconducting wires. We argue that our results are generic and apply to a large class of models. We discuss the implications for experiments on spin-orbit coupled nanowires coated with superconducting film and for LaAlO${}_{3}$/SrTiO${}_{3}$ interfaces.
The protein synthetic machinery: ribosomes and cell-free systems.

Publisher Summary This chapter discusses several approaches that can be used in analyzing protein synthesis machinery. In vivo, the kinetics of reactions can be monitored; the polyribosome sizes and distribution can be measured; and the cells can be perturbed by changing internal ion concentration with external treatments such as ammonia or acetate that change internal pH, or calcium ionophores that change internal calcium concentrations. This method gives insight into the ionic events responsible for the activation of protein synthesis in fertilized eggs. Advantages of using in vitro systems are that individual components can be tested, and specific responses to a large variety of inhibitors of protein synthesis that are not membrane soluble can be measured. A goal of in vitro studies is to mimic both the repression of protein synthesis in eggs, and the derepression of the inhibited components by using only the discrete molecules and ions involved in the repression and activation processes.
THE BEHAVIOR OF THE NUCLEIC ACIDS DURING THE EARLY DEVELOPMENT OF THE SEA URCHIN EGG (ARBACIA)

1. The unfertilized Arbacia egg contains an average of 20γ x 10–3 ribonucleic acid and 0.7 to 1γ x 10–3 desoxyribonucleic acid. 2. During the first 24 hours of development, the amount of ribonucleic acid per embryo remains practically unchanged whereas that of desoxyribonucleic acid steadily increases. At the end of this period, the amount of desoxyribonucleic acid per embryo is 10 to 15 times larger than that of the unfertilized egg.
Degradation of Avalanche Ruggedness of Power Diodes by Thermally Induced Local Breakdown

The investigations into the failure mechanism of the power diode during the undamped inductive load switching (UIS) are presented using experiments and numerical simulations. During the avalanche event, the temperature rise due to the localized avalanche current increases breakdown voltage and as a result, the location of the peak impact ionization moves around in the device. This behavior alters the current distribution under the UIS condition, depending on the initial location of breakdown. When the avalanche event starts at the edge termination, the avalanche current redistribution into the active area is limited, resulting in weak avalanche capability. Therefore, for high avalanche ruggedness, the diode should have the uniformly distributed avalanche current, which can be observed when the breakdown starts at the bottom of anode junction. In this work, it is shown that the avalanche capability of the power diodes during the UIS conditions is strongly dependent on the location of the initial breakdown and the mismatch of the termination design and starting material can significantly degrade the avalanche capability. Therefore, the power diode with high avalanche capability should be designed by elaborately controlling the location of initial breakdown.
Ca²+ signaling in B cells

An increase in intracellular Ca²+ concentration is one of the major initial steps in B-cell activation that occurs within minutes after antigen receptor (BCR) engagement. In recent years, significant advances have been made in characterizing molecular mechanisms of Ca²+ signaling in lymphocytes, although the majority of work was done on T cells. This mini-review discusses several underexplored areas of Ca²+ signaling in B cells: (1) Ca²+ signaling in immune synapse and multifaceted Ca²+ responses within a single cell, (2) source of Ca²+ involved in Ca²+-dependent protein phosphorylation events and the role of store-operated influx, (3) role of BCR coreceptors in Ca²+ signaling, and (4) Ca²+ signaling and maintenance of B-cell tolerance and clinical significance of Ca²+ signaling alterations.
Blood lactate and metabolic responses to controlled frequency breathing during graded swimming.

Controlled frequency breathing (CFB) is a training technique used by swimmers in an effort to simulate high-intensity workloads by limiting oxygen availability to the body and stimulating anaerobic metabolism. During CFB, a swimmer voluntarily restricts breathing, which, theoretically, limits oxygen availability and stimulates anaerobic metabolism. The purpose of this study was to determine the influence of CFB on blood lactate and metabolic responses during graded increases in swimming intensity. A free swimming (FS) protocol was used to determine blood lactate and heart rate (HR) responses to CFB, while a tethered swimming (TS) protocol was used to determine blood lactate, HR, and ventilatory responses to CFB. The subjects swam four 3-minute trials at workloads of 55, 65, 75, and 85% of peak intensity during both protocols. A total of 46 competitive collegiate swimmers participated in the study. Thirty-four subjects (14 men and 20 women) completed the FS protocol, and 12 subjects (7 men and 5 women) completed the TS protocol. CFB reduced ventilation and Vo(2) (p 0.05). Our findings demonstrate that although CFB does not alter the blood lactate response to graded increases in swimming intensity, it appears to reduce the ventilatory and HR responses to exercise. Thus, swim coaches can use CFB at moderate intensities to simulate high-intensity training but should consider adjusting HR training zones to reflect the reduction in HR associated with reduced ventilation.
The late pubertal cascade in perimenarchial monkeys: onset of asymmetrical ovarian estradiol secretion and bioassayable luteinizing hormone release.

Changes in ovarian function and pituitary gonadotropin secretion were studied in perimenarchial rhesus monkeys. Even in the premenarchial interval, a modest degree of asymmetrical ovarian estradiol secretion was evident. A progression toward marked asymmetry of ovarian function continued after menarche, culminating in ovulatory menstrual cycles with intermenstrual intervals of approximately 28 days. Among postmenarchial monkeys manifesting five or fewer episodes of overt uterine bleeding, no ovulations were detected despite estradiol elevations similar to those of adults in the midfollicular phase. Soon thereafter, among individuals usually having more than 10 menses, the first ovulations were likely to be achieved. The initiation of estrogen-positive feedback, driving the surge modes of gonadotropin secretion, was accompanied by the onset of a striking disparity between bioassayable vs.immunoassayable LH in the circulation. In this report we describe a cascade of late pubertal events including: 1) the gr...
SU(2)×U(1) vectorlike model: New leptons, quarks, and the axion question

We present a detailed study of an SU(2) x U(1) gauge theory of the weak and electromagnetic interactions in which parity is broken spontaneously. A global, chiral U(1) symmetry is incorporated in order to avoid a zeroth-order neutrino mass. We investigate an eight-quark scheme and two different lepton assignments, each of which produces almost pure vector coupling of the electron to the weak neutral current. One lepton assignment leads to a calculable neutrino mass, while the other one leads to calculable electron and neutrino masses. There are heavy leptons in the models whose masses are mildly constrained by the bound on the electron-neutrino mass. The neutrino-mass limit and the interpretation of the UPSILON as a bound state of a heavy right-handed quark require that the expectation value of a ''left'' Higgs doublet be small compared to that of a ''right'' Higgs doublet. Because of the global U(1) symmetry, if one or more extra Higgs particles and/or quark singlets are added then an axion can be present. The conditions under which an axion appears are sketched, and its couplings and mass are less restricted than those discussed by other authors. Alternatively, a soft breaking of the U(1) symmetry can be introducedmore » to avoid a Goldstone boson and to insure that both Higgs doublets have nonzero vacuum expectation values. Suppression of strong CP violation can be naturally achieved in this case, and the axion is not present. Both the axion and the soft-breaking possibilities are discussed.« less
Transport of cadmium and other metals in the blood of the bivalve mollusc Mercenaria mercenaria

The distribution of metals (Ba, Cr, Cu, Fe, Mn, Ni and Zn) in the blood plasma and the circulating hemocytes was determined for a eulamellibranch bivalve, the quahog Mercenaria mercenaria (L.), collected from a relatively clean site at Falmouth, Massachusetts, USA. Whole blood volume was an exponential function of quahog length (Y=5.71×10-5 X3.0678; Y=ml of whole blood; X=mm length). Of this volume, 1.2±0.3% (\((\bar X \pm {\rm{SD)}}\)) was attributable to blood cells. Total metal content (μg metal, or μg metal normalized per g of whole blood) was much higher in blood plasma than in hemocytes. In quahogs exposed in the laboratory to 100 ppb 109Cd, 93.0% of the total accumulated blood Cd was in the plasma rather than in the circulating hemocytes (7.0%), irrespective of the length of exposure (1 h to 31 d). Less than 5% of the plasma Cd was either Cd2+, small inorganic Cd complexes or bound to organic molecules with a molecular weight smaller than 1 000. Cadmium was primarily bound to high molecular weight protein(s) (>60 000 daltons) within the plasma. This plasma protein-Cd complex has a low affinity constant (approximately 104M-1), indicating non-specific Cd binding, although the capacity for Cd-binding in the plasma is great (as high as 200 μg Cd per ml of plasma). Blood plasma may be far more important in metal transport than has previously been realized.
Fixed points and domain growth for the Potts model

We present a Monte Carlo renormalization-group analysis of the dynamics of the eight-state Potts model with nearest- and next-nearest-neighbor interactions after a quench below its phase-transition point. Our results sugest the existence of at least two distinct fixed points at zero temperature. One is associated with a freezing behavior while the second is associated with equilibration. Our conclusion is that the freezing fixed point is only attractive for quenches to zero temperature, while the equilibration fixed point is attractive for quenches to finite temperature.
The design of multiproduct batch plants under uncertainty with staged expansion

Abstract Flexibility is of particular relevance for contemporary multiproduct batch operations. This paper presents a conceptual formulation for solving the multiproduct batch design problem under uncertainty. The constraints are separated into hard and soft categories and feasibility criteria are developed for both types. Penalty terms are included in the objective functions to reflect the expected profit loss due to unfilled orders, thereby associating a cost with violation of the soft constraints. Short- and long-term variations are allowed, with staged expansion introduced to accommodate the long-term uncertainties. The solution approach is illustrated using an application involving a step change in the demand levels.
Time course of thyroid response to rising and to falling blood levels of thyroxine.

SummaryIn a study of the relationship between blood thyroxine concentration and thyrotrophin (TSH) secretion, the time course of thyroid response to thyroxine injection has been examined. As measured by thyroid I131 release curves pituitary-thyroid inhibition occurred immediately following sudden increase in blood thyroxine concentration in 2 rabbits and within 3 hours in a third. Groups of rats were pre-treated with radioiodine and thyroid inhibition produced by injection of thyroxine. Protein bound iodine (PBI) levels in the blood were followed serially as the inhibitory effects of the injected material gradually decreased. Pituitary-thyroid activation (as measured by sharp increase in PBI131) was observed as PBI levels fell from 5.2 to 4.0 μg% (control PBI 4.0 μg%) over a 6-hour period.
Neonatal ischemic brain injury: what every radiologist needs to know

We present a pictorial review of neonatal ischemic brain injury and look at its pathophysiology, imaging features and differential diagnoses from a radiologist’s perspective. The concept of perinatal stroke is defined and its distinction from hypoxic-ischemic injury is emphasized. A brief review of recent imaging advances is included and a diagnostic approach to neonatal ischemic brain injury is suggested.
Safety baseballs and chest protectors: a systematic review on the prevention of commotio cordis.

AbstractObjective: To determine whether chest protectors and/or safety baseballs reduce the incidence of commotio cordis during sport through a review of the best available evidence. Data sources: PubMed, Ovid Medline, and Embase databases from 1950 to 2009. We selected articles according to “death, sudden, cardiac,” “commotio cordis,” “sports equipment,” and “protective devices.” We identified 17 articles in the systematic literature search. Of these, 7 articles met inclusion criteria. Three independent reviewers reviewed the articles. The study results and generated conclusions were extracted and agreed on. Results: The softest safety baseball shows statistically significant reductions in the incidence of ventricular fibrillation (VF) at all velocities compared with standard baseballs in the 3 studies that evaluated their use. Different degrees of softness did not show statistically significant reductions in VF. In the 3 studies that evaluated the use of chest protectors against controls, there was an i...
Platelet glycoproteins IIb and IIIa associated with blood monocytes are derived from platelets

Platelet glycoprotein IIb/IIIa (GP IIb/IIIa), the receptor complex for fibrinogen, has been regarded as a megakaryocyte/platelet lineage-restricted antigen. Recently, however, it has been reported that GP IIb/IIIa is expressed in blood monocytes. Studies were performed to establish the origin and immunological characteristics of monocyte-associated glycoproteins IIb and IIIa (GPs IIb and IIIa). Preparations of blood monocytes containing varying platelet-monocyte ratios were metabolically labeled with [35S]methionine with the expectation that any newly synthesized GPs IIb and IIIa would be monocyte-derived, since platelets have only rudimentary protein synthetic apparatuses. Analyses of sodium dodecyl sulfate (SDS) gels of homogenates of cell preparations containing from 200 to 5:1 platelet-monocyte ratios revealed that unlabeled GPs IIb and IIIa were readily immunoisolated using protein A-Sepharose immunobeads. However, fluorographic analyses of the same cell preparations pulse-labeled with [35S]methionine failed to demonstrate synthesis of GP IIb or IIIa. Additionally, no GP IIb or IIIa was detected when immunoisolation was carried out in pure preparations of monocytes containing less than 1:100 platelet-monocyte ratios and SDS acrylamide gels were stained by the sensitive silver stain method. Furthermore, heterologous polyspecific antisera and two monoclonal antibody preparations against GPs IIb and IIIa, which bound to platelets, failed to bind to monocyte membranes. Thus, evidence was presented that indicated that monocytes do not synthesize platelet GPs IIb and IIIa and that detection of these molecules in blood monocyte preparations reflects platelet contamination.
The therapeutic potential of regulatory T cells for the treatment of autoimmune disease

Introduction: Immune tolerance remains the holy grail of therapeutic immunology in the fields of organ and tissue transplant rejection, autoimmune diseases, and allergy and asthma. We have learned that FoxP3+CD4+ regulatory T cells play a vital role in both the induction and maintenance of self-tolerance.Areas covered: In this opinion piece, we highlight regulatory T cells (Treg) cell biology and novel immune treatments to take advantage of these cells as potent therapeutics. We discuss the potential to utilize Treg and Treg-friendly therapies to replace current general immunosuppressives and induce tolerance as a path towards a drug-free existence without associated toxicities.Expert opinion: Finally, we opine on the fact that biomedicine sits on the cusp of a new revolution: the use of human cells as versatile therapeutic engines. We highlight the challenges and opportunities associated with the development of a foundational cellular engineering science that provides a systematic framework for safely an...
A Novel Assessment of Braking Reaction Time Following THA Using a New Fully Interactive Driving Simulator

Background After total hip replacement surgery, patients are eager to resume the activities of daily life, particularly driving. Most surgeons recommend waiting 6 weeks after surgery to resume driving; however, there is no evidence to indicate that patients cannot resume driving earlier.
Nitric-oxide synthase and neurodegeneration/neuroprotection

Glaucoma is an optic neuropathy in which the retinal ganglion cells and their axons, which package and transmit visual impulses from the photoreceptors and associated retinal interneurons to the brain, die individually or in small groups, typically over many years (Figs. 1 and 2) (1). The resulting functional deficit is the second leading cause of irreversible visual loss in the U.S., and the most common cause among African-Americans. In its most prevalent form, the condition is strongly dependent upon age, race, and family history. Approximately 3–5% of White Americans, 10% of African-Americans, and 20% of Afro-Caribbeans over the age of 70 years have the disease (2–5). As lifespan and the proportion of the population comprising the aged increase, so will the number and proportion afflicted.
Centrifugal fibres synapse on dopaminergic interplexiform cells in the teleost retina

In teleost fish, centrifugal fibres originating in the olfactory bulb and containing FMRFamide-like and luteinizing hormone releasing hormone (LHRH)-like peptides project to the retina and terminate along the border of the inner nuclear and inner plexif orm layers1–3. Using a novel simultaneous two-colour immunolabelling technique, we have found that these centrifugal fibres are often closely apposed to the dopaminergic interplexiform cells. Contacts between centrifugal fibres and dopaminergic interplexiform cells were observed by electron microscopy to be conventional type synaptic junctions. Since the dopaminergic interplexiform cells make synapses on horizontal and bipolar cells, providing an intraretinal centrifugal pathway for information flow from the inner to the outer plexiform layers4–6, we conclude that every neuron in the teleost retina is potentially susceptible to central influences via these centrifugal fibres and dopaminergic interplexiform cells.
CT-guided adrenal biopsy: comparison of ipsilateral decubitus versus prone patient positioning for biopsy approach

To compare ipsilateral decubitus and prone patient positioning for performing computed tomography guided adrenal biopsy using the requirements for out-of-plane approach (OOP) and the needle insertion time (NIT) as a surrogate for procedure complexity. The study included 106 adrenal biopsies performed in 104 patients with lesions measuring ≤4 cm that were divided into two groups: Ipsilateral decubitus (Group I) and prone (Group II) positions. The frequency of use of an OOP biopsy path and the NIT were recorded as well as diagnostic yield, adverse events and transgression of organs to approach the target lesion. Groups I and II comprised 54 and 50 patients, respectively. The use of the OOP approach was significantly less frequent (P < 0.01) in Group I (n = 4) compared to Group II (n = 38). NIT was statistically shorter (P < 0.01) in Group I (9 min and 43 s) compared to Group II (19 min and 7 s). There were fewer organs traversed in Group I versus Group II. Diagnostic yield and post-biopsy complications were equal in both groups. Ipsilateral adrenal biopsy approach is a less complex, equally reliable and safe compared to the prone approach based on the less frequent use of the OOP approach and the shorter NIT. • Ipsilateral adrenal biopsy decubitus positioning provides a direct, non-transpulmonary path for sampling • Ipsilateral decubitus positioning reduces the need for potentially dangerous out-of-plane approaches (OOP) • Ipsilateral decubitus and prone positioning are equally reliable and safe techniques
Construct validity of a simulator for myringotomy with ventilation tube insertion

OBJECTIVES: To establish construct validity of an anatomic model as a simulator for myringotomy with ventilation tube insertion and to assess its subjective appeal. STUDY DESIGN: Cross-sectional, repeated-measures comparative evaluation of simulator. SETTING: University academic otolaryngology residency program. SUBJECTS AND METHODS: Using an anatomic model of the human auricle, ear canal, eardrum, and middle ear space, 18 otolaryngologists of various levels of training performed 10 timed procedures: myringotomy with ventilation tube insertion. Errors were recorded, and participants reported the quality of their experience. RESULTS: Both time-to-completion and errors per trial discriminated novices from non-novice participants; novices (02:23, 95% confidence interval [CI], 01:42-03:04) were 3.6 times slower than non-novices (00:39, 95% CI, 00:35-00:43) and 6.5 times more error prone (novices 2.16 errors/trial, 95% CI, 1.68-2.64; non-novices 0.33 errors/trial, 95% CI, 0.21-0.45). Errors were strongly correlated with prior surgical experience. All participants required more time to complete the first trial, and their performance stabilized thereafter. Overall, the simulation was perceived as a valuable experience. CONCLUSION: Our model is a valid platform for simulating myringotomy with ventilation tube insertion. The model discriminates novices from non-novices, has a learning curve, and is perceived to be a valuable and realistic teaching tool by users.
γ-AApeptides bind to RNA by mimicking RNA-binding proteins

The interactions between proteins and RNAs are of vital importance for many cellular processes, including transcription and processing of RNA, translation, and viral infections. Here we report an γ-AApeptide that can mimic HIV-1 Tat protein and bind to TAR RNAs of HIV and BIV with nanomolar affinity, comparable to that of the RNA-binding fragment of Tat (amino acids 49–58). The interaction is resistant to the presence of a large excess of tRNA. With resistance to proteolytic hydrolysis and limitless potential for diversification, γ-AApeptides may emerge as a new class of peptidomimetics to modulate RNA-protein interactions.
A narrowband MIMO channel model with 3-D scattering

This paper presents a channel model for multiple input multiple output (MIMO) systems in the presence of three-dimensional (3-D) scattering. The model combines improved sum-of-sinusoids simulation models proposed for Rayleigh fading channels, and the two-dimensional (2-D) models proposed for MIMO systems, in a 3-D scattering environment. The distribution of 3-D scattering is assumed to be uniform in horizontal plane and Gaussian in the elevated plane. Simulation results showed that the new model satisfies the desired statistics with less Doppler spread, and hence can be used to generate independent fading channels for MIMO systems. The generated channels can be further processed to obtain correlated MIMO channels through the exploitation of correlation matrices at the transmit and receive sides. The resultant channel can then he used to simulate MIMO systems for a better system performance prediction.
Mechanical Behavior of an Intercritically Annealed and Isothermally Transformed Low C Alloy Steel with Ferrite-Bainite- Austenite Microstructures

A low C steel containing 1.5% Mn, 1.2% Si, and 0.1% Mo was inter-critically annealed at 760 and 820° C, and either quenched in oil to room temperature, or isothermally held at 400° C and then oil quenched to room temperature. The specimens were subjected to tensile testing at temperatures between − 80° C and 120° C, and the microstructures were evaluated by light and scanning electron microscopy and x-ray diffraction. The austenite formed during intercritical annealing transformed to martensite with negligible retained austenite as a result of the direct oil quenching, while it transformed to bainite with significant amounts of retained austenite, up to 7.5%, during isothermal transformation. The retained austenite improved ductility at strength levels between 700 and 800 MPa by strain induced transformation of austenite to martensite. The benefit of the retained austenite peaked at testing temperatures between −30 and 70° C.
Building Organizational Capabilities for Managing Economic Crisis: The Role of Market Orientation and Strategic Flexibility:

Abstract Firms around the world often must manage and survive economic crises. Recent cases in Asia, Eastern Europe, and South America bear testimony to this point. As economic weak spots are integrated into the global economy, it is timely to develop an understanding of organizational capabilities that can help firms manage their way through such crises. The authors investigate the role of market orientation and strategic flexibility in helping Thai firms manage the recent Asian crisis. The results demonstrate the contingent nature of the influence of market orientation and strategic flexibility on firm performance after a crisis has occurred. As hypothesized, market orientation has an adverse effect on firm performance after a crisis. This effect is moderated by demand and technological uncertainty and is enhanced by competitive intensity. In contrast, strategic flexibility has a positive influence on firm performance after a crisis, which is enhanced by competitive intensity and moderated by demand and...
Chaotic Responses of a Two-Degree-of-Freedom Elastic-Plastic Beam Model to Short Pulse Loading

The paper discusses chaotic response behavior of a beam model whose ends are fixed, so that shallow arch action prevails after moderate plastic straining has occurred due to a short pulse of transverse loading. Examples of anomalous displacement-time histories of a uniform beam are first shown. These motivated the present study of a two-degree-of-freedom model of Shanley type. Calculations confirm these behaviors as symptoms of chaotic unpredictability . Evidence of chaos is seen in displacement-time histories, in phase plane and power spectral diagrams, and especially in extreme sensitivity to parameters. The exponential nature of the latter is confirmed by calculations of conventional Lyapunov exponents and also by a direct method. The two-degree-of-freedom model allows use of the energy approach found helpful for the single-degree-of-freedom model (Borino et al., 1989). The strain energy is plotted as a surface over the displacement coordinate plane, which depends on the plastic strains. Contrasting with the single-degree-of-freedom case, the energy diagram illuminates the possibility of chaotic vibrations in an initial phase, and the eventual transition to a smaller amplitude nonchaotic vibration which is finally damped out. Properties of the response are further illustrated by samples of solution trajectories in a fixed total energy plane and by related Poincare section plots.
Rotaviruses preferentially bind O-linked sialylglycoconjugates and sialomucins

Rotaviruses are the most common cause of severe gastroenteritis in infants and children worldwide. Early events of virus binding and entry are the critical determinants of cellular permissiveness to rotavirus replication. The only known ligands for rotaviruses are sialic acids. We now report that simian rotaviruses bind preferentially to a subset of sialylated glycoconjugates, i.e. glycoproteins containing O-linked sialic acid moieties. Rotaviruses are able to distinguish between sialylated trisaccharide ligands presented as neoglycolipids. Higher avidity binding by rotaviruses is explained by multivalent binding to clustered sialic acid moieties. Our in vitro data are extended to explain the protective effect of mucins in the murine model of rotavirus disease and the specific binding by rotavirus to a high molecular weight sialomucin in the infant mouse intestine. Rotavirus binding to a sialomucin may be analogous to selectin-mediated mechanisms of cellular adhesion, and may be advantageous to the virus in the dynamic environment of the intestine.
Characterization of three new chlorophyll-protein complexes

Abstract Three new chlorophyll-proteins with electrophoretic mobilities intermediate between those of the P700 chl a-protein and the light-harvesting chl a,b-protein complexes are reported and their absorption spectra and polypeptide composition are characterized. Two of these chlorophyll-proteins, bands IIb and IIa, contain approximately equal amounts of chl a and b, have polypeptide compositions similar to that of the light-harvesting chl a,b-protein and probably represent oligomers of the latter complex. The third new chlorophyll-protein contains only chl a and its major polypeptide(s) is in the 42 kd region. Indirect evidence indicates this chlorophyll-protein is associated with the reaction-center of photosystem II.
Fuzzy Logic Control of a Laboratory Magnetic Levitation System

This paper deals with the Fuzzy Logic control of a Magnetic Levitation system [1] available in the Robotics and Control Laboratory at Duke University. The laboratory Magnetic Levitation system primarily consists of a metallic ball, an electromagnet and an infrared optical sensor. The objective of the control experiment is to balance the metallic ball in a magnetic field at a desired position against gravity. The dynamics and control complexity of the system makes it an ideal control laboratory experiment. The student can design their own control schemes and/or change the parameters on the existing control modes supplied with the Magnetic Levitation system, and evaluate and compare their performances. In the process, they overcome challenges such as designing various control techniques, choose which specific control strategy to use, and learn how to optimize it. A Fuzzy Logic control scheme was designed and implemented to control the Magnetic Levitation system. Position and rate of change of position were the inputs to Fuzzy Logic Controller. Experiments were performed on the existing Magnetic Levitation system. Results from these experiments and digital simulation are presented in the paper.© 2003 ASME
Integrated resource allocation in heterogeneous SAN data centers

Modern data centers are complex distributed environments with application workloads requiring multiple resources like processing (CPU), storage and network. Allocation of these resources to workloads needs to be handled in an integrated manner to adequately capture the relationships between different resource nodes like connectivity between an application server and storage controller in the storage area network (SAN). As data centers grow over time, heterogeneous resources coexist at the same time and this heterogeneity adds further complexity to manual resource allocation.In this work, we describe various challenges and key insights in performing fast, automatic integrated resource allocation. We briefly introduce our novel framework called SPARK (Stable-Proposals-And-Resource Knapsacks) that uses server virtualization to address combined placement of application data and CPU in SAN data centers. SPARK is based on two well-studied problems -- Stable Marriage and Knapsacks -- and is simple, fast, versatile and highly scalable. Our initial experiments show promise of our approach, consistently outperforming natural candidate algorithms by 30-40% and being within 4% of the LP-based optimal values for a wide range of experiments.
Concrete model theory for a class of operators

The operator Lƒ(t, λ) = e−iλ(t, λ) − 2e−iλ ∝t2π ∝Tƒ(s, x) e(s, t) dvs(x) dm(s) acting on H=∝02π⊕L2(vt), where m and vt, 0 ⩽ t ⩽ 2π are measures on [0, 2π] with m smooth and e(s, t) = exp[−∝ts∝Tdvλ(θ) dm(λ)], satisfies rank(I − LL∗) = rank(I − L∗L) = 1. It is, therefore, unitarily equivalent to a scalar Sz.-Nagy-Foias canonical model. The purpose of this paper is to determine the model explicitly and to give a formula for the unitary equivalence.
Improved graft mesenchymal stem cell survival in ischemic heart with a hypoxia-regulated heme oxygenase-1 vector.

Objectives The goal of this study was to modify mesenchymal stem cells (MSCs) cells with a hypoxia-regulated heme oxygenase-1 (HO-1) plasmid to enhance the survival of MSCs in acute myocardial infarction (MI) heart. Background Although stem cells are being tested clinically for cardiac repair, graft cells die in the ischemic heart because of the effects of hypoxia/reoxygenation, inflammatory cytokines, and proapoptotic factors. Heme oxygenase-1 is a key component in inhibiting most of these factors. Methods Mesenchymal stem cells from bone marrow were transfected with either HO-1 or LacZ plasmids. Cell apoptosis was assayed in vitro after hypoxia-reoxygen treatment. In vivo, 1 × 10 6 of male MSC HO-1 , MSC LacZ , MSCs, or medium was injected into mouse hearts 1 h after MI (n = 16/group). Cell survival was assessed in a gender-mismatched transplantation model. Apoptosis, left ventricular remodeling, and cardiac function were tested in a gender-matched model. Results In the ischemic myocardium, the MSC HO-1 group had greater expression of HO-1 and a 2-fold reduction in the number of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate in situ nick end labeling-positive cells compared with the MSC LacZ group. At seven days after implantation, the survival MSC HO-1 was five-fold greater than the MSC LacZ group; MSC HO-1 also attenuated left ventricular remodeling and enhanced the functional recovery of infarcted hearts two weeks after MI. Conclusions A hypoxia-regulated HO-1 vector modification of MSCs enhances the tolerance of engrafted MSCs to hypoxia-reoxygen injury in vitro and improves their viability in ischemic hearts. This demonstration is the first showing that a physiologically inducible vector expressing of HO-1 genes improves the survival of stem cells in myocardial ischemia.
Solid-phase synthesis of bleomycin A5 and three monosaccharide analogues: Exploring the role of the carbohydrate moiety in RNA cleavage

The solid-phase synthesis of bleomycin A5 (BLM A5) and three monosaccharide analogues is presented. The monosaccharide analogues incorporated α-d-mannose, α-l-gulose, and α-l-rhamnose moieties in lieu of the disaccharide normally present in BLM A5. Also explored were the abilities of each of the monosaccharide congeners to cleave a 53-nt RNA. The elaboration of these carbohydrate-modified bleomycin analogues helps to define the role of the disaccharide moiety during the RNA cleavage event. The relatively facile solid-phase synthesis of bleomycin A5 and each of the carbohydrate analogues constitutes an important advance in the continuing mechanistic studies of bleomycin.
Vertical water mass circulation and the distribution of radiolaria in surface sediments of the Gulf of California

Abstract Quantitative analysis of microfossils from sediment cores taken in the Gulf of California shows that the distribution of radiolaria is controlled by both surface ocean conditions and vertical circulation patterns in this marginal sea. Fifty-four surface sediment samples from intermediate water depths were used in this study. Samples were taken from surface scrapings of box cores or large diameter gravity cores to insure that the samples represented recent deposition. Q -mode factor analysis was used to divide the radiolarian population found in the Gulf of California into three assemblages. The first is made up of species typical of the Gulf. These species are, in general, not a major part of the open ocean radiolarian fauna. The general geographic distribution of this assemblage shows a maximum abundance in the north-central part of the Gulf where warmer high salinity water is found. This assemblage is also important in areas of upwelling. The second fauna is dominated by radiolaria typical of the subtropical Pacific Ocean. This assemblage dominates in the southern part of the Gulf. The last assemblage is dominated by species commonly found in the eastern boundary of the North Pacific and is found in areas of upwelling within the Gulf of California. Analysis shows that the first two assemblages are strongly influenced by the vertical structure of the southern part of the Gulf of California. The Gulf assemblage shows a maximum in samples taken between 600 and 800 m water depth. The Subtropical assemblage shows high values in shallow sites and in samples taken in water depths greater than 800 m, and a distinct minimum at intermediate depths. The fauna typical of the North Pacific eastern boundary current shows no depth preference. The maximum in the Gulf assemblage coincides with the depth of strong southerly flow of warmer higher salinity water out of the Gulf of California. This suggests that the abundance of the Gulf assemblage in the southern end of the Gulf of California is in part controlled by advection and thus vertical circulation has an important part in controlling the distribution of radiolaria in the sediments of the Gulf of California.
Modeling the severe acute respiratory syndrome (SARS) outbreak in Beijing: an agent-based approach

The spread of Severe Acute Respiratory Syndrome (SARS) is an intrinsic spatial and temporal process. This paper reports the use of an agent-based approach to model the spread of SARS in Beijing and to examine the effectiveness of intervention strategies. A case study of simulation of SARS epidemic in Beijing, China in 2003 has been conducted by tracing close contacts of cases. Based on comparison of the simulation results with the actual cases, it was found that the agent-based approach can capture the SARS transmission from individual to individual and can demonstrate the public-health efforts in the control of SARS.
Simultaneous echo refocusing in EPI

A method to encode multiple two-dimensional Fourier transform (2D FT) images within a single echo train is presented. This new method, simultaneous echo refocusing (SER), is a departure from prior echo planar image (EPI) sequences which use repeated single-shot echo trains for multislice imaging. SER simultaneously acquires multiple slices in a single-shot echo train utilizing a shared refocusing process. The SER technique acquires data faster than conventional multislice EPI since it uses fewer gradient switchings and fewer preparation pulses such as diffusion gradients. SER introduces a new capability to simultaneously record multiple spatially separated sources of physiologic information in subsecond image acquisitions, which enables several applications that are dependent on temporal coherence in MRI data including velocity vector field mapping and brain activation mapping.
Conversion of industrial paper sludge to ethanol: fractionation of sludge and its impact.

Paper sludge is an attractive biomass source for the conversion to ethanol due to its low cost and the lack of severe pretreatment required. Four sludges from pulp and paper operations including both virgin kraft (VK) and recycled and deinking (RD) paper mills were analyzed. A fractionation process using a laboratory screen was utilized to produce a fiber-rich stream for enzymatic hydrolysis. This process removed 82–98 % of the ash with fiber yields from 39 to 69 %. Even though sludges in both non-fractionated and fractionated scenarios were pH-adjusted, total sugar conversion was still improved by 12–27 % by fractionation with 4.5 times less acid required for pH adjustment. Fermentation of the fractionated sludges showed very high ethanol yields. Acid insoluble clay adsorbs 3–5 mg enzyme per gram of clay depending on enzyme dosage. Acid soluble CaCO3 adsorbs about half of the enzyme compared to clay. Fractionation efficiency was also evaluated by testing different size mesh screen openings (100 to 500 mesh). The 400-mesh screen presented the best fiber yield, ash removal and ash fractionation ratio for both VK and RD sludges. The ash-rich streams have a lower C/N ratio than the original sludge which improves its suitability as soil amendment.
THE VALUE OF A REGULATORY SEAL OF APPROVAL

I investigate whether obtaining a regulatory seal of approval adds to firm value. For a sample of thirty-four firms that acquired the insured deposits of failed banks, I find a significantly greater price response for firms that could benefit from obtaining a regulatory seal of approval than for firms that had recently obtained a similar form of approval. Further, abnormal returns to winning bidders are significantly larger when a regulatory seal of approval is likely to be more valuable, i.e., when the industry faces severe economic problems. In addition, bidder gains are significant only in markets where regulatory certification of a firm's health is important—markets that have recently experienced several bank failures. Finally, wealth transfers from the FDIC insurance fund may contribute to bidder gains. The evidence suggests that obtaining a regulatory seal of approval can positively affect firm value.
EVALUATION OF SELECTED IN-FURROW AND SEED APPLIED INSECTICIDES FOR CONTROL OF THRIPS, 2004

Selected insecticides applied onto seed or into the seed furrow at planting were evaluated for control of thrips . ‘Delta Pine 444 B/R’ cotton was planted 28 Apr at the Virginia Tech Tidewater Agric. Res. & Ext. Ctr., Suffolk, VA, using 36-inch row spacing. In-furrow (IF) treatments were applied into the seed furrow at the time of planting using tractor-mounted inverted jars with lid holes calibrated to deliver exact amounts via gravity. Valent prepared seed treatments/slurries on 14 Apr. A RCB design was used with 4 replicates; plots were 4 rows by 40 ft. Thrips injury to plants was determined by visually rating injury using a 0 to 5 scale, where 0 = no thrips induced plant injury, 1 = 10% injured leaves, no bud injury; 2 = 25% injured leaves, no bud injury; 3 = 75% injured leaves, and 0 to 25% buds injured; 4 = 90% injured leaves, and greater than 25% buds injured; and 5 = dead plants. Yield was determined by harvesting the two center rows of each plot (80 row ft) using a commercial 2-row John Deere cotton picker. Sub-samples were ginned to determine lint versus seed and trash weight (42% lint, 58% seed and trash). Data were analyzed using ANOVA and means were separated using LSD (P ≤ 0.10).
Advances in pharmacogenomic research and development

Technological achievements in the last 5 to 10 yr and their application to sequencing and polymorphism discovery in the human genome have fostered a renewed interest in the genetic basis of drug response. Consequently, the field of pharmacogenetics/pharmacogenomics has been gaining momentum, fueled not only on technology but also on results of empirical studies of the human genome and on genetic epidemiology studies of real drugs in patient populations. This review discusses some of the recent advances in pharmacogenomic research and development over the last few years that include understanding the architecture of the human genome, the creation of population deoxyribonucleic acid (DNA)/data banks, assessment of the clinical validity of genetic markers, and experience with regulatory aspects of pharmacogenomics.
Constant pH Molecular Dynamics Simulations of Nucleic Acids in Explicit Solvent.

The nucleosides of adenine and cytosine have pKa values of 3.50 and 4.08, respectively, and are assumed to be unprotonated under physiological conditions. However, evidence from recent NMR and X-ray crystallography studies has revealed the prevalence of protonated adenine and cytosine in RNA macromolecules. Such nucleotides with elevated pKa values may play a role in stabilizing RNA structure and participate in the mechanism of ribozyme catalysis. With the work presented here, we establish the framework and demonstrate the first constant pH MD simulations (CPHMD) for nucleic acids in explicit solvent, in which the protonation state is coupled to the dynamical evolution of the RNA system via λ-dynamics. We adopt the new functional form λNexp for λ that was recently developed for multisite λ-dynamics (MSλD) and demonstrate good sampling characteristics in which rapid and frequent transitions between the protonated and unprotonated states at pH = pKa are achieved. Our calculated pKa values of simple nucleoti...
The Experimental Alzheimer's Disease Drug Posiphen [(+)-Phenserine] Lowers Amyloid-β Peptide Levels in Cell Culture and Mice

Major characteristics of Alzheimer's disease (AD) are synaptic loss, cholinergic dysfunction, and abnormal protein depositions in the brain. The amyloid beta-peptide (Abeta), a proteolytic fragment of amyloid beta precursor protein (APP), aggregates to form neuritic plaques and has a causative role in AD. A present focus of AD research is to develop safe Abeta-lowering drugs. A selective acetylcholinesterase inhibitor, phenserine, in current human trials lowers both APP and Abeta. Phenserine is dose-limited in animals by its cholinergic actions; its cholinergically inactive enantiomer, posiphen (+)-[phenserine], was assessed. In cultured human neuroblastoma cells, posiphen, like phenserine, dose- and time-dependently lowered APP and Abeta levels by reducing the APP synthesis rate. This action translated to an in vivo system. Posiphen administration to mice (7.5-75 mg/kg daily, 21 consecutive days) significantly decreased levels of total APP (tissue mass-adjusted) in a dose-dependent manner. Abeta40 and Abeta42 levels were significantly lowered by posiphen (> or =15 mg/kg) compared with controls. The activities of alpha-, beta-, and gamma-secretases were assessed in the same brain samples, and beta-secretase activity was significantly reduced. Posiphen, like phenserine, can lower Abeta via multiple mechanisms and represents an interesting drug candidate for AD treatment.
Simulating market effects on boundedly rational agents in control of the dynamic dispatching of actors in network-based operations

This work investigates the effect of market structure on the performance of actors who dispatch resources in network-based organizations. As digital tracking of these actors increases in scope and specificity, it is becoming feasible to extract computational models of dispatcher decision making which can be used to simulate market influences on these decisions. This work presents (1) a method for extracting computational decision models from transaction data and (2) a sensitivity analysis of the effect of market design (i.e., payment structure) and predictability of dispatcher decisions on system performance. The approach is illustrated for the case of a recent debris removal mission following extensive tornadoes in Alabama in 2011 which involved daily dispatching of an average of 28 hauling vehicles to an average of 6 work locations in the region of interest. Results of model validation against these historical tracking data are presented, along with implications for future work.