Number Of Beads Research Articles

Validation of a Pictorial Survey Tool to Measure Time Use in an African Urban Setting

Background: Disease often depends on how a host interacts with his or her environment. This interaction is important for respiratory infectious diseases, where built environments may promote transmission. To learn about time use, or the amount of time people spend in a day doing various activities, in sub-Saharan Africa may be difficult because of low literacy and different cultural perceptions of time. We developed a culturally appropriate survey tool to measure time use called the mweso game. Method: Three cross-sectional studies were performed among adults in Kampala, Uganda, to evaluate criterion and construct validity and to assess reliability of the mweso game. The mweso game was compared to actual elapsed time, a detailed 24-hr recall survey, and between three different recall periods. In all analyses, the mean number of beads, or hours, was calculated; Pearson correlation coefficients and Cronbach’s α were estimated. Results: Criterion validity for the use of beads to measure time was fair; mean values tended to be accurate, but there was variability in estimates of time across participants. When comparing the mweso game to the 24-hr recall survey, construct validity was very good. For most of the settings, the difference between measurements was less than one hour; there was good to excellent correlation for most settings. Reliability and internal consistency were best for time use at home and work. Conclusions: We have developed the mweso game as an instrument to measure time use in the context of low literacy and different cultural perceptions of time. The mweso game was valid and reliable, especially for measuring time use at home and work. With further validation, it may prove useful in measuring time use and in studying its relation to transmission of respiratory infectious diseases.

Standard of proof and intolerance of uncertainty in obsessive-compulsive disorder and social anxiety disorder

Background and objectivesResearchers have identified intolerance of uncertainty (IU) as a dysfunctional thought that contributes to OCD. Case examples of OCD suggest that uncertainty and anxiety persist despite low likelihoods of feared outcomes. In this study we examined how people with OCD react to minimal amounts of uncertainty relative to non-anxious individuals and a clinical comparison group of people with social anxiety disorder (SAD). MethodsWe created a questionnaire to measure the distress people feel when there is only minimal uncertainty regarding a given outcome and if they prefer situations with the certainty of negative outcomes in the present versus living with uncertainty. Part two of our study tested whether IU is related to performance on neutral and idiographic versions of the Beads Task. ResultsOCD and SAD subjects reacted to hypothetical scenarios involving minimal risk with greater negative affect than did non-anxious subjects; however, after repeating analyses to account for comorbid disorders, OCD subjects’ scores did not differ from those of non-anxious subjects. Only SAD subjects showed a preference for negative information in the present versus the uncertainty of a future outcome. Part two of our study revealed that self-reported IU was only marginally associated with performance on the neutral Beads Task. LimitationsHigh rates of comorbidity made it difficult to identify the specific relationship of IU with other anxiety disorders. ConclusionsIU for general, non-OCD specific scenarios may not figure prominently in all individuals with OCD, but rather may play a larger, more consistent role in anxiety disorders such as SAD. Additionally, the number of beads or words viewed on Beads Task may be an inadequate behavioral measure of IU.

Simulation of the Motion of Arbitrarily Shaped Protein Molecules in Nanopores using Clusters of Rigid Spherical Particles

Ionic current measurement through nanopores can be an effective tool to analyze individual proteins. So far, the shape of non-spherical proteins moving through nanopores has been modelled as ellipsoids. To provide a more realistic description, we modelled anisotropic protein shapes as a cluster of unequally-sized and charged spheres. We rigorously solved Stokes equations of motion coupled to Laplace equation to compute the hydrodynamic and electrophoretic tensors of these clusters, which made it possible to treat the cluster as one single rigid body. Once computed, these tensors can be used to simulate the dynamics and corresponding current blockage inside the nanopore. While the computational time of the cluster's tensors is strongly dependent on the number of beads in the cluster, the simulation of the motion and current blockage is independent of it. To provide a realistic bead model for the proteins, we started from a downloaded Protein Data Bank (PDB) file, which contains the coordinates of all atoms in a protein. While using one bead per atom, we performed a progressive coarse-graining, thus reducing the number of beads used to describe the structure of the protein, to obtain the minimum level of description necessary to capture the behavior of the protein. This is achieved by using the previously discussed model to obtain its hydrodynamic and electrophoretic mobility tensors. The minimal model is obtained when the additional of beads will not substantially change the simulated motion and current blockage. The use of coarse-grained protein models makes it possible to carry out the simulations with a standard computer. We anticipate that this model will be an enabling tool to correlate experimental nanopores results from protein translocations with simulations in order to recover structural information of proteins.

Dopamine manipulations drive changes in information sampling in healthy volunteers.

Information sampling is the cognitive process of accumulating information before committing to a decision. Patients across numerous disorders show decreased information sampling relative to controls. Here, we used the Beads and the Best Choice Tasks to study the role of dopamine signaling in information sampling. Participants were given placebo, amisulpride, or ropinirole in each session, in a double-blind cross-over design. We found that ropinirole (agonist) increased the number of beads drawn in the Beads Task specifically when participants faced a loss, and decreased the rank of the chosen option in the Best Choice Task. These effects are likely driven by a combination of effects at presynaptic D2 receptors, which affect dopamine release, and post-synaptic D2 receptors. Increased D2 relative to D1 receptor activation in the striatum leads to increased sampling in the loss condition in the Beads Task. It also leads to choice of a poorer ranked option in the Best Choice Task. Decreased D2 relative to D1 receptor activation leads to decreased sampling in the Beads Task in the loss condition.

Effective production of keratinase by gellan gum-immobilised Alcaligenes sp. AQ05-001 using heavy metal-free and polluted feather wastes as substrates.

The ability of gellan gum-immobilised cells of the heavy metal-tolerant bacterium Alcaligenes sp. AQ05-001 to utilise both heavy metal-free and heavy metal-polluted feathers (HMPFs) as substrates to produce keratinase enzyme was studied. Optimisation of the media pH, incubation temperature and immobilisation parameters (bead size, bead number, gellan gum concentration) was determined for the best possible production of keratinase using the one-factor-at-a-time technique. The results showed that the immobilised cells could tolerate a broader range of heavy metal concentrations and produced higher keratinase activity at a gellan gum concentration of 0.8% (w/v), a bead size of 3mm, bead number of 250, pH of 8 and temperature of 30°C. The entrapped bacterium was used repeatedly for ten cycles to produce keratinase using feathers polluted with 25ppm of Co, Cu and Ag as substrates without the need for desorption. However, its inability to tolerate/utilise feathers polluted with Hg, Pb, and Zn above 5ppm, and Ag and Cd above 10ppm resulted in a considerable decrease in keratinase production. Furthermore, the immobilised cells could retain approximately 95% of their keratinase production capacity when 5ppm of Co, Cu, and Ag, and 10ppm of As and Cd were used to pollute feathers. When the feathers containing a mixture of Ag, Co, and Cu at 25ppm each and Hg, Ni, Pb, and Zn at 5ppm each were used as substrates, the immobilised cells maintained their operational stability and biological activity (keratinase production) at the end of 3rd and 4th cycles, respectively. The study indicates that HMPF can be effectively utilised as a substrate by the immobilised-cell system of Alcaligenes sp. AQ05-001 for the semi-continuous production of keratinase enzyme.

High macrophage activities are associated with advanced periductal fibrosis in chronic Opisthorchis viverrini infection

Liver fluke infection caused by Opisthorchis viverrini induces several hepatobiliary conditions including advanced periductal fibrosis (APF) and cholangiocarcinoma (CCA), but >25% of the infected population develops APF and 1% develop CCA. The innate immune response is the first line of defence, and macrophages are critical regulators of fibrosis. We hypothesized that macrophages from infected individuals have different capacities to either promote or suppress periductal fibrosis. We compared phagocytic activities of macrophages of healthy individuals and Oviverrini-infected individuals±APF, and found that macrophages from infected individuals with APF ingested significantly higher numbers of beads compared with healthy controls and Oviverrini-infected individuals without APF. To further investigate proteolytic activity, we monitored real-time phagosomal proteolysis of beads conjugated to DQ-BODIPY-BSA using live cell imaging. We show that macrophages from Oviverrini-infected individuals with APF also have elevated phagosomal proteolysis activity, which is consistent with their increased phagocytic activity. Additionally, stimulated ROS production by blood monocytes was higher in individuals with APF compared with healthy controls and infected individuals without APF. These results suggest that during Oviverrini infection, macrophages with high phagocytic and proteolytic activities together with elevated ROS production are the phenotypes that can promote tissue damage, which results in periductal fibrosis.

Application of In Vivo Confocal Microscopy in Dry Eye Disease.

Confocal microscopy is a new, emerging, noninvasive technology that can aid in the in vivo assessment of structural changes in several ocular surface diseases at the cellular level. In the dry eye field, in vivo confocal microscopy has been applied to the examination of the cornea, bulbar and palpebral conjunctiva, Meibomian gland, and lacrimal gland. The device can assess the morphology, including superficial/wing/basal epithelial cell density, stromal keratocyte density, endothelial cell density, nerve fiber density, the number of beadings, nerve tortuosity, nerve reflectivity, and inflammatory cell density in the cornea. Furthermore, the device can not only assess epithelial cell density and area, goblet cell, microcyst, and inflammatory cell density but also the cellular architecture, including nucleocytoplasmic ratio in conjunctiva. The device also can disclose acinar unit density, acinar unit longest diameter, acinar unit shortest diameter, and inflammatory cell density in the Meibomian gland and lacrimal gland by other potential applications. Relevant research in Europe and the United States focused on the morphologic changes in the cornea in the dry eye field, while Japanese research focused on the conjunctival, Meibomian gland, and lacrimal gland alterations. The application of in vivo confocal microscopy in dry eye disease will be a powerful method to evaluate the morphologic change of the ocular surface around the world in the future.

2079. The Relation Between Panel Reactive Antibody Assay and Cytomegalovirus Reactivation in Seropositive Solid Organ Transplantation Recipients

BackgroundCytomegalovirus (CMV) can lead to severe morbidities and mortalities including pneumonia in particular as well as graft dysfunction through indirect immunomodulation in solid-organ transplantation recipients. High degree of HLA mismatch is a well-known risk factor of post-transplant (Tx) CMV reactivation. Recent laboratory advances for evaluating HLA mismatch can measure existence of donor-specific antibodies for single HLA allele; however, there was little evidence whether single panel reactive Ab (PRA) assay could predict CMV reactivation in SOT recipients.MethodsWe retrospectively analyzed pre-Tx HLA mismatch tests in total 300 of SOT recipients. All of them were CMV seropositive in donor and recipients and received regular blood CMV VL monitoring during ≥6 months after SOT. Lung (N = 83) and heart (N = 76) recipients received universal prophylaxis for 3 months, and kidney (N = 63) and liver (N = 78) received pre-emptive CMV therapy. The single PRA test for HLA class I/II was performed by bead-based immunoassay. The percentage of PRA was calculated by following formula: (the number of positive bead reaction/the number of beads in the assay) × 100. We categorized HLA-Ab specificity into two groups according to median fluorescent intensity (MFI) of bead; (1) strong with ≥10,000 of MFI, (2) not strong with <10,000. The calculated PRA was obtained from the frequency of HLA alleles in normal Korean population according to formula from U.S. Organ Procurement and Transplantation Network.ResultsThe reactivator with ever ≥500 IU/mL of CMV had significantly higher positive percentage of HLA Class I screening test compared than nonreactivator (33.8% vs. 11.6%, P = 0.004) but not class II (P = 0.085). The PRA and cPRA values only for HLA class I were significantly lower in nonreactivator (PRA, 0 [0–0] % vs. 0 [0–15] %, P = 0.005; cPRA, 0.5 [0–15.5] % vs. 4.5 [0–41.5] %, P = 0.030), but not class II (PRA, P = 0.393, cPRA, P = 0.446). The percentage of strong MFI group for class I in nonreactivator was significantly lower than those in reactivator (7.1% vs. 28.8%, P = 0.028), but not class II (11.6% vs. 15.8%, P = 0.512). The maximal levels of CMV VL did not have any significant correlation to MFI values of Class I nor II.ConclusionSeropositive SOT recipients with strong PRA or cPRA values for HLA Class I in pre-Tx single PRA test had higher risk of CMV replication.Disclosures All authors: No reported disclosures.

Relations between the sub-molecula and the cooperative scales in the molecular dynamics of the glass-forming liquids

The molecules of the supercooled liquids in the cooperative molecular dynamics are partitioning to specific dynamic units, known as “beads”. The beads have been defined as the smallest units, forming the heat capacity of the supercooled liquids. The beads appear as a sub-molecular scale in the dynamics of the glass-forming liquids. In the Adam-Gibbs theory the number of molecules, rearranging simultaneously, has been defined as the size of the cooperative rearranging region and these regions form the second larger molecular scale in molecular dynamics. Due to a noticeable discrepancy in estimating the number of beads in the molecules by the empirical rules as well as by theoretical models the relations between these two scales are not well known. Recently, a new thermodynamic method for estimating the number of the beads in the molecules and a rule for the examination of their temperature dependence have been suggested. By these methods 48 low-molecular supercooled liquids are investigated and the relations between these two molecular scales and the structure of the molecules have been found. The estimated number of configuration beads is compared with the number of the structural units (the chemical groups, the ions and the atoms), with the assigned number by the empirical rules and with the ones calculated, based on a Lennar-Jones model of the random first order transition theory. A constant and two kinds of temperature dependence of the number of the beads in the molecules of different liquids have been revealed. A molecular basis, forming the fragility of the supercooled liquids, has been found. From the results obtained, the investigated liquids are classified in several groups following the logical line in the formation of the beads.

Maintained thymic output of conventional and regulatory T cells during human pregnancy

Maintained thymic output of conventional and regulatory T cells during human pregnancy

Gastric motor and sensory function in health assessed by magnetic resonance imaging: Establishment of reference intervals for the Nottingham test meal in healthy subjects.

Current investigations of gastric emptying rarely identify the cause of symptoms or provide a definitive diagnosis in patients with dyspepsia. This study assessed gastric function by magnetic resonance imaging (MRI) using the modular "Nottingham test meal" (NTM) in healthy volunteers (HVs). The NTM comprises (a) 400mL liquid nutrient (0.75kcal/mL) labeled with Gadolinium-DOTA and (b) an optional solid component (12 agar-beads [0kcal]). Filling sensations were documented. MRI measurements of gastric volume, emptying, contraction wave frequency, and secretion were obtained using validated methods. Gastric function was measured in a population of 73 HVs stratified for age and sex. NTM induced moderate satiety and fullness. Labeled fluid was observed in the small bowel in all subjects after meal ingestion ("early-phase" GE). Secretion was rapid such that postprandial gastric content volume was often greater than meal volume (GCV0>400mL), and there was increasing dilution of the meal during the study (P<0.001). Gastric half-time was median 66-minutes (95% reference interval 35 to 161-minutes ["late-phase" GE]). The number of intact agar beads in the stomach was 7/12 (58%) at 60-minutes and 1/12 (8%) at 120-minutes. Age, bodyweight and sex had measurable effects on gastric function; however, these were small compared to inter-individual variation for most metrics. Reference intervals are presented for MRI measurements of gastric function assessed for the mixed liquid/solid NTM. Studies in patients will determine which metrics are of clinical value and also whether the reference intervals presented here offer optimal diagnostic sensitivity and specificity.

Dissipative particle dynamics modeling of hydrogel swelling by osmotic ensemble method.

An osmotic ensemble method for dissipative particle dynamics (DPD) is developed for simulating the swelling behavior of polymer networks in aqueous solvent under constant solvent chemical potential, number of polymer beads, pressure, and temperature conditions. We apply a Langevin piston method to control the pressure of the polymer-solvent mixture. Chemical potential equilibrium is achieved via Monte Carlo insertions and deletions of solvent beads based on the total free energy change of the gel. The osmotic ensemble simulation produces swelling kinetics of hydrogels in excellent agreement with that obtained by previous methods but significantly reduces computational costs. The results show gel swelling as a result of the mechanical balance between osmotic pressure induced by the mixing of the polymer and solvent and elastic force originated from the network deformation. The simulations also elucidate the influence of solvent conditions and network topology on the degree of swelling. The bulk modulus of the model gel is probed at different solvency and its behavior is consistent with the prediction of Flory-Rehner theory. The osmotic ensemble DPD will permit the study of mechanical properties of hydrogels in mesoscale simulations and can be extended to model other complex fluid systems in chemical equilibrium under isothermal-isobaric conditions.

Suspensions of supracolloidal magnetic polymers: Self-assembly properties from computer simulations

We study self-assembly in suspensions of supracolloidal polymer-like structures made of crosslinked magnetic particles. Inspired by self-assembly motifs observed for dipolar hard spheres, we focus on four different topologies of the polymer-like structures: linear chains, rings, Y-shaped and X-shaped polymers. We show how the presence of the crosslinkers, the number of beads in the polymer and the magnetic interparticle interaction affect the structure of the suspension. It turns out that for the same set of parameters, the rings are the least active in assembling larger structures, whereas the system of Y- and especially X-like magnetic polymers tends to form very large loose aggregates.

Which part of a chain breaks?

This work investigates the dynamics of a one-dimensional homogeneous harmonic chain on a horizontal table. One end is anchored to a wall; the other (free) end is pulled by an external force. A Green's function is derived to calculate the response to a generic pulling force. As an example, I assume that the magnitude of the pulling force increases with time at a uniform rate β. If the number of beads and springs used to model the chain is large, the extension of each spring takes a simple closed form, which is a piecewise-linear function of time. Under an additional assumption that a spring breaks when its extension exceeds a certain threshold, results show that for large β the spring breaks near the pulling end, whereas the breaking point can be located close to the wall by choosing small β. More precisely, the breaking point moves back and forth along the chain as β decreases, which has been called “anomalous” breaking in the context of the pull-or-jerk experiment. Although the experiment has been explained in terms of inertia, its meaning can be fully captured by discussing the competition between intrinsic and extrinsic time scales of forced oscillation.

P158 Selective antibody reactivity against HLA-DQA1 in transplant candidates is rare

Aim Single antigen bead (SAB) assay is used to test the presence of antibodies against HLA antigens including HLA-DQ. Each SAB DQ bead is comprised of an alpha and a beta chain representative of an HLA-DQ antigen. A positive result represents reactivity to either or both chains. The aim of this report is to evaluate the frequency of HLA-DQ alpha antibodies in transplant candidates known to have Class II antibody. Methods Class II SAB data (One Lambda Inc.) was collected from 2346 transplant candidates at Brigham and Women’s Hospital from 6/9/2012 to 1/15/2014. The reactivity to HLA-DQ alpha was considered positive (MFI >3000) if all the beads containing a specific HLA-DQ alpha were reactive but the beads with corresponding HLA-DQ beta chain were negative. For example, the sera which were considered positive for HLA DQA1*03:02, had positive reaction with two beads containing DQA1*03:02, [DQA1*03:02, DQB1*03:02] and [DQA1*03:02, DQB1*03:03], but negative reaction with five beads positive for either DQB1*03:02 or DQB1*03:03 combined with DQA1 chains other than DQA1*03:02. Results Of the 29 HLA-DQ assay beads, 12 different HLA-DQ alpha chains were combined with different HLA-DQ beta chains. Sixteen (16/2346, 0.69%) sera reacted with beads specific for DQA1*03:02. These sera reacted with the alpha chain in combination with either DQB1*03:02 or DQB1*03:03. A similar pattern could be observed with sera (17/2346, 0.72%) that had specific reactivity to DQA1*02:01. Interestingly, none of the sera appeared to react selectively with DQA1*01:01, DQA1*01:02, DQA1*03:01, or DQA1*05:01. Although reactions with beads coated with DQA1*01:03, DQA1*03:03, DQA1*04:01, DQA1*05:03, DQA1*05:05, or DQA1*06:01 were present, they could not be attributed to DQA1 as the number of reactions or beads were not sufficient to rule out reactivity to DQB1. Out of the 33 patients who showed reactivity to either DQA1*03:02 or DQA1*02:01, only three (9.1%) had reactivity exclusively to the HLA-DQ alpha chain with no reactivity to any other HLA class II antigen. Conclusions The frequency of antibodies which appear to have HLA-DQ alpha specificity in transplant candidates is low (1.4%). Our results imply that a large number of sensitized patients will have to be studied in order to determine the clinical significance of antibodies to DQAlpha.

Two-dimensional scattering patterns and stress-strain relation of elongated clay nano composite gels: Molecular dynamics simulation analysis

To verify the structure-properties relation of elongated clay nanocomposite (NC) gels through two-dimensional scattering patterns (2DSPs), we performed coarse-grained molecular dynamics (CGMD) simulations of a bead-spring model of NC gels. In order to reproduce the 2DSP behavior, we modeled a clay particle as a disk-like aggregation of a large number of beads. In our model of polymer networks filled with the clays, we maintained the structural relations of the clays such as shape, size, and concentration, and emulated gelation processes through CGMD simulations. As results, the model with a scale map with 1 σ = 2 nm, where σ is the scale unit of CGMD simulations, succeeded in reproducing behaviors of stress-strain relations and 2DSPs. After our pseudo reaction processes with bonding between the ends of the polymers and between polymer ends and clays, uniaxial stretching CGMD simulations were performed. It is found that rapid increases in the estimated stress-strain relation for large stretching ratio were caused by the percolated network of the NC gel model with high NC concentration. We confirmed that the dependences of clay concentration and stretching ratio on 2DSP and stress were consistent with the small-angle neutron scattering experiments and tensile experiments, respectively.

Optical vortices in the Ginzburg–Landau equation with cubic–quintic nonlinearity

In a dissipative system with cubic–quintic nonlinearity, the curious evolution of optical vortex beams characterized by different topological charges (TCs) is simulated numerically and presented their evolution profiles. We find that new vortices will be induced during propagation, and the behavior of vortices, as affected by the TC and the number of beads of the incident beam, as well as its size, is also discussed. Common rules associated with the initial conditions coming from various incident beams are developed to determine the number of induced vortices and the corresponding rotation direction. Attributed to the nonlinearity, during propagation we see the beams slowly expand to induce new vortices, which commonly appear in oppositely charged pairs, while the net topological charge of the vortex is conserved. Our results not only deepen the understanding of optical vortices, but also widen their potential applications.

From shell to glass: how beads reflect the changing cultural landscape of the seventeenth-century lower Potomac River valley

ABSTRACTThis article examines over 7,500 beads from eight Native archaeological sites located in the lower Potomac River valley in order to understand how changes in bead assemblages between AD 1300 and 1712 expressed an ever-evolving Chesapeake cultural landscape. This analysis demonstrates clear differences in the types and distributions of beads from mortuary and domestic/nonmortuary contexts. Ossuary contexts contained the highest frequency of beads with the number of beads increasing over time. Following the arrival of English settlers in the 1620s, glass beads begin to appear in ossuary contexts. Beads from domestic or nonmortuary contexts are fewer in number, and those present were manufactured using local materials, including bone and clay, as well as shell. However, after 1680, there is a shift from shell beads being predominate on Native sites, to sites containing exclusively glass beads, red and black glass beads in particular. Post-1680 sites appear to reflect Piscataway displacement and the disruption of indigenous trade routes, leading Natives to obtain beads from colonial vendors. The distribution of bead color, an important attribute for communicating Native states of being, also shifts after 1680, with assemblages once dominated by white shell beads now dominated by black and red glass beads.

The necklace process: A generating function approach

The “necklace process”, a procedure constructing necklaces of black and white beads by randomly choosing positions to insert new beads (whose color is uniquely determined based on the chosen location), is revisited. This article illustrates how, after deriving the corresponding bivariate probability generating function, the characterization of the asymptotic limiting distribution of the number of beads of a given color follows as a straightforward consequence within the analytic combinatorics framework.

The effect of task difficulty on decision-making

The aim was to determine whether there are differences between groups in jumping to conclusions and the number of beads required to make a decision based on task difficulty. An assessment was made of 19 patients with non-affective psychosis, 19 with obsessive–compulsive disorder (OCD), and 19 healthy controls. The Beads Task scale was used in its two versions. Patients with non-affective psychosis jumped to conclusions. There was significant interaction between group and task difficulty. Increased difficulty of the task did not affect the number of beads patients with non-affective psychosis or OCD needed to make their decision. However, healthy controls needed to see more beads before they could make a decision in the hard test than in the easy one. Patients with non-affective psychosis jump to conclusions, but neither this group nor the OCD patients benefit from the changes in task difficulty when making their decisions.