Mechanically driven particles as simple models for silo discharge, collective behavior of animate beings, and human egress dynamics

Cavity parameter deviations from their nominal values affect phase-locking in vertical-cavity surface-emitting lasers (VCSEL) arrays. The phase-locking tolerance is studied analytically and numerically for both random as well as systematic parameter variations. Parameter-induced deviations among the cavity eigenfrequencies cause the dominant effect. For small externally imposed variations, self-regulated nonlinear frequency pulling among cavities overcomes original detuning and permits phase-locking. The root mean square (rms) tolerance threshold is derived by solving a quasi-random matrix eigenvalue under simplifying assumptions. Tolerance increases with intercavity coupling strength and decreases with the array size M. Systematic variations, such as thermal drifts, exhibit a lower tolerance decreasing as /spl prop/1/M or faster, compared to random variations /spl prop/1//spl radic/M. Theory results qualitatively agree with large size array simulations employing actively coupled rate equations.

EP 57. Biological motion perception in Parkinson‘s disease

A network evaluation of human and animal movement data across multiple swine farm systems in North America

Dynamical downscaling with high-resolution regional climate models may offer the possibility of realistically reproducing precipitation and weather events in climate simulations. As resolutions fall to order kilometers, the use of explicit rather than parametrized convection may offer even greater fidelity. However, these increased model resolutions both allow and require increasingly complex diagnostics for evaluating model fidelity. In this study we use a suite of dynamically downscaled simulations of the summertime U.S. (WRF driven by NCEP) with systematic variations in parameters and treatment of convection as a test case for evaluation of model precipitation. In particular, we use a novel rainstorm identification and tracking algorithm that allocates essentially all rainfall to individual precipitation events (Chang et al. 2016). This approach allows multiple insights, including that, at least in these runs, model wet bias is driven by excessive areal extent of precipitating events. Biases are time-dependent, producing excessive diurnal cycle amplitude. We show that this effect is produced not by new production of events but by excessive enlargement of long-lived precipitation events during daytime, and that in the domain average, precipitation biases appear best represented as additive offsets. Of all model configurations evaluated, convection-permitting simulations most consistently reduced biases in precipitation event characteristics.

Poultry production has significantly increased worldwide, along with the number of avian influenza (AI) outbreaks and the potential threat for human pandemic emergence. The role of wild bird movements in this global spread has been extensively studied while the role of animal, human and fomite movement within commercial poultry production and trade networks remains poorly understood. The aim of this work is to better understand these roles in relation to the different routes of AI spread. A scoping literature review was conducted according to the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) using a search algorithm combining twelve domains linked to AI spread and animal/human movements within poultry production and trade networks. Only 28 out of 3,978 articles retrieved dealt especially with the role of animal, human and fomite movements in AI spread within the international trade network (4 articles), the national trade network (8 articles) and the production network (16 articles). While the role of animal movements in AI spread within national trade networks has been largely identified, human and fomite movements have been considered more at risk for AI spread within national production networks. However, the role of these movements has never been demonstrated with field data, and production networks have only been partially studied and never at international level. The complexity of poultry production networks and the limited access to production and trade data are important barriers to this knowledge. There is a need to study the role of animal and human movements within poultry production and trade networks in the global spread of AI in partnership with both public and private actors to fill this gap.

Poultry production has significantly increased worldwide, along with the number of avian influenza (AI) outbreaks and the potential threat for human pandemic emergence. The role of wild bird movements in this global spread has been extensively studied while the role of animal, human and fomite movement within commercial poultry production and trade networks remains poorly understood. The aim of this work is to better understand these roles in relation to the different routes of AI spread. A scoping literature review was conducted according to the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) using a search algorithm combining twelve domains linked to AI spread and animal/human movements within poultry production and trade networks. Only 28 out of 3,978 articles retrieved dealt especially with the role of animal, human and fomite movements in AI spread within the international trade network (4 articles), the national trade network (8 articles) and the production network (16 articles). While the role of animal movements in AI spread within national trade networks has been largely identified, human and fomite movements have been considered more at risk for AI spread within national production networks. However, the role of these movements has never been demonstrated with field data, and production networks have only been partially studied and never at international level. The complexity of poultry production networks and the limited access to production and trade data are important barriers to this knowledge. There is a need to study the role of animal and human movements within poultry production and trade networks in the global spread of AI in partnership with both public and private actors to fill this gap.

The shufflon of plasmid R64 consists of four DNA segments separated and flanked by seven sfx recombination sites. Rci-mediated recombination between any inverted sfx sequences causes inversion of the DNA segments independently or in groups. The R64 shufflon selects one of seven pilV genes encoding type IV pilus adhesins, in which the N-terminal region is constant, while the C-terminal regions are variable. The R64 sfx sequences are asymmetric. The sfx central region and right arm sequences are conserved, but left arm sequences are not. Here we constructed a symmetric sfx sequence, in which the sfx left arm sequence was changed to the inverted repeat of the right arm sequence and made artificial shufflon segments carrying symmetric sfx sequences in inverted or direct orientations. The symmetric sfx sequence exhibited the highest inversion frequency in a shufflon segment flanked by two inverted sfx sequences. Rci-dependent deletion of a shufflon segment flanked by two direct symmetric sfx sequences was observed, suggesting that asymmetry of R64 sfx sequences inhibits recombination between direct sfx sequences. In addition, intermolecular recombination between symmetric sfx sequences was also observed. The extra C-terminal domain of Rci was shown to be essential for inversion of the R64 shufflon using asymmetric sfx sequences but not essential for recombination using symmetric sfx sequences, suggesting that the Rci C-terminal segment helps the binding of Rci to asymmetric sfx sequences. Rci protein lacking the C-terminal domain bound to both arms of symmetric sfx sequence but only to the right arm of asymmetric sfx sequence.

In human lateral temporal cortex, some regions show specific sensitivity to human motion. Here we examine whether such effects reflect a general biological-nonbiological organizational principle or a process specific to human-agent processing by comparing processing of human, animal, and tool motion in a functional magnetic resonance imaging (fMRI) experiment with healthy participants and a voxel-based lesion-symptom mapping (VLSM) study of patients with brain damage (77 stroke patients). The fMRI experiment revealed that in the lateral temporal cortex, the posterior superior temporal sulcus shows a preference for human and animal motion, whereas the middle part of the right superior temporal sulcus/gyrus (mSTS/STG) shows a preference for human and functional tool motion. VLSM analyses also revealed that damage to this right mSTS/STG region led to more severe impairment in the recognition of human and functional tool motion relative to animal motion, indicating the causal role of this brain area in human-agent motion processing. The findings for the right mSTS/STG cannot be reduced to a preference for articulated motion or processing of social variables since neither factor is involved in functional tool motion recognition. We conclude that a unidimensional biological-nonbiological distinction cannot fully explain the visual motion effects in lateral temporal cortex. Instead, the results suggest the existence of distinct components in right posterior temporal cortex and mSTS/STG that are associated, respectively, with biological motion and human-agent motion processing.

Spatial heterogeneity is the presence of structural instability over space, producing systematic parameter variation or differential response functions as we move through the spatial sample of data observations. Past econometric approaches to this problem have involved random coefficient models, spatial adaptive filtering, spatial expansion, and switching regression methods (Anselin). Despite the fact that agricultural production takes place in the spatial plane, the spatial dimension of agricultural economic models has not been subjected to formal spatial econometric methods. A fair amount of attention has been paid to spatial orientation issues in agricultural studies of crop yields, where spatial statistical tools have been used to facilitate experimental design of crop yield studies (see, for example, Brewer and Mead). Econometric methods that deal with spatial heterogeneity would seem to have a great deal of intuitive appeal in econometric analysis of agricultural economic relationships. The present study examines the structural stability over time and space of simple economic relations between spatial output of tobacco, acreage harvested, past season prices, and climatic variables, finding evidence of systematic parameter variation over time and space. This type of variation should come as no surprise, given the inherently spatial nature of agricultural production and forces such as weather, regional market influences, regional production similarities, and soil conditions, which are all likely to produce spatial variation. In order to model such spatial variation, a Bayesian multiprocess mixture approach is used to 'mix' parameter distributions from spatially related areas. The intuition behind this is that

Ground truth construction and parameter tuning for the detection of sleep spindle timing in rodents

New look at foot and mouth epidemic

We study the passage of active and passive granular particles through a bottleneck under gravitational bias. The grains are pharmaceutical capsules with spherocylindrical shapes on a vibrating table. The vibrating ground plate is slightly tilted in order to break the in-plane symmetry and to give particles a motivation to move in a preferential direction. The passage through a narrow gate with openings comparable to the grain length is studied using video imaging. Particle positions and velocities are extracted from the recorded frames. We find striking differences between the behaviour of asymmetric, active capsules and symmetric, passive ones. The active grains show an astonishingly strong dependence of the passage rates on the gate width, while for passive grains, this dependence is linear as expected. The cumulative distributions of delays between subsequent particles passing the outlet, a key parameter in egress studies, also differ substantially between active and passive grains. Tilt angle and excitation parameters have only little influence on the observed dynamic features, they merely rescale time.

The crystal and molecular structures of five compounds of the general formula R2Sn(S2CNR′2)Cl have been determined at room temperature. The colorless crystals of [Me2Sn(S2CNEt2)Cl] are monoclinic, space group P21/c with unit cell dimensions a = 10.896(2) Å, b = 9.869(4) Å, c = 12.722(2) Å, β = 105.08(1)°, Z = 4 and D x = 1.672 Mg m−3. The colorless crystals of [Me2Sn(S2CNCy2)Cl] are monoclinic, space group P21/c with unit cell dimensions a = 6.758(6) Å, b = 19.046(3) Å, c = 15.190(5) Å, β = 98.09(4)°, Z = 4 and D x = 1.512 Mg m−3. Crystals of colorless [tBu2Sn(S2CN(Et)Cy)Cl] are monoclinic, space group P21/n with unit cell dimensions a = 13.481(5) Å, b = 11.466(5) Å, c = 15.351(8) Å, β = 107.51(4)°, Z = 4 and D x = 1.382 Mg m−3. The colorless crystals of [Cy2Sn(S2CNEt2)Cl] are monoclinic, space group P21/c with unit cell dimensions a = 17.107(6) Å, b = 11.134(2) Å, c = 11.953(6) Å, β = 104.00(3)°, Z = 4 and D x = 1.409 Mg m−3. The colorless crystals of [Cy2Sn(S2CNCy2)Cl] are monoclinic, space group P21/n with unit cell dimensions a = 11.411(7) Å, b = 16.942(5) Å, c = 14.712(5) Å, β = 100.45(3)°, Z = 4 and D x = 1.370 Mg m−3. The structures were solved by direct methods and each refined by a full-matrix least-squares procedure to final R = 0.039 using 1367 reflections for [Me2Sn(S2CNEt2)Cl]; to R = 0.038 using 1881 reflections for [Me2Sn(S2CNCy2)Cl]; to R = 0.049 using 2707 reflections for [tBu2Sn(S2CN(Et)Cy)Cl]; to final R = 0.042 for 1914 reflections for [Cy2Sn(S2CNEt2)Cl]; and to final R = 0.045 for 2550 reflections for [Cy2Sn(S2CNCy2)Cl]. The crystallographic study shows that the tin atom in the R2Sn(S2CNR′2)Cl compounds exists in a distorted trigonal bipyramidal geometry in which the equatorial plane is defined by the two carbon atoms of the tin-bound organic substituents as well as more tightly held sulfur atom derived from an asymmetrically chelating dithiocarbamate ligand; the axial positions are defined by the less tightly held sulfur atom as well as the chloride atom. Attempts to correlate the Sn-ligand parameters with systematic variations in the Lewis acidity of the tin center (i.e. by moderating R) and the Lewis basicity of the dithiocarbamate ligand (i.e. by moderating R′) were unsuccessful across the series. The compounds have been subjected to geometry optimisation calculations which revealed that more symmetric structures exist in the gas phase. Systematic variations in the Sn-ligand parameters for the gas phase structures could be correlated with the Lewis basicity of the dithiocarbamate ligands in contrast to the solid state structures. Also, trends were found as the Lewis acidity of the tin center was varied. These trends could not, however, be correlated with the electronic structures of the tin-bound substituents alone, indicating that the steric profiles of the substituents also play an important role in moderating the Lewis acidity of the tin center. The results of the combined crystallographic/theoretical investigation of the R2Sn(S2CNR′2)Cl structures indicate that intermolecular forces, i.e. crystal packing effects, do exert a significant influence on the molecular geometry in these systems.

Radiomic descriptors from magnetic resonance imaging (MRI) are promising for disease diagnosis and characterization but may be sensitive to differences in imaging parameters. To evaluate the repeatability and robustness of radiomic descriptors within healthy brain tissue regions on prospectively acquired MRI scans; in a test-retest setting, under controlled systematic variations of MRI acquisition parameters, and after postprocessing. Prospective. Fifteen healthy participants. A 3.0 T, axial T2 -weighted 2D turbo spin-echo pulse sequence, 181 scans acquired (2 test/retest reference scans and 12 with systematic variations in contrast weighting, resolution, and acceleration per participant; removing scans with artifacts). One hundred and forty-six radiomic descriptors were extracted from a contiguous 2D region of white matter in each scan, before and after postprocessing. Repeatability was assessed in a test/retest setting and between manual and automated annotations for the reference scan. Robustness was evaluated between the reference scan and each group of variant scans (contrast weighting, resolution, and acceleration). Both repeatability and robustness were quantified as the proportion of radiomic descriptors that fell into distinct ranges of the concordance correlation coefficient (CCC): excellent (CCC > 0.85), good (0.7 ≤ CCC ≤ 0.85), moderate (0.5 ≤ CCC < 0.7), and poor (CCC < 0.5); for unprocessed and postprocessed scans separately. Good to excellent repeatability was observed for 52% of radiomic descriptors between test/retest scans and 48% of descriptors between automated vs. manual annotations, respectively. Contrast weighting (TR/TE) changes were associated with the largest proportion of highly robust radiomic descriptors (21%, after processing). Image resolution changes resulted in the largest proportion of poorly robust radiomic descriptors (97%, before postprocessing). Postprocessing of images with only resolution/acceleration differences resulted in 73% of radiomic descriptors showing poor robustness. Many radiomic descriptors appear to be nonrobust across variations in MR contrast weighting, resolution, and acceleration, as well in test-retest settings, depending on feature formulation and postprocessing. 2 TECHNICAL EFFICACY: Stage 2.

The magnetic properties of ${\mathrm{Co}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}{\mathrm{Cl}}_{2}{\mathrm{\ensuremath{\cdot}}\mathrm{H}}_{2}\mathrm{O}$ are examined by dc magnetization and susceptibility measurements, for $x=0.05,$ 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, and 0.95 between 1.8 and 300 K. The pure components are a quasi-one-dimensional Heisenberg antiferromagnet (Mn) and an antiferromagnetic reentrant spin glass (Co) with some low-dimensional character. The Curie and Weiss constants, in ${\ensuremath{\chi}}_{M}=C/(T\ensuremath{-}\ensuremath{\theta}),$ show regular composition dependence, with $\ensuremath{\theta}(x)$ varying nonlinearly from positive to negative values as x increases. Antiferromagnetic maxima often occur, and transition temperatures are estimated for most mixtures. The $T\ensuremath{-}x$ diagram shows two descending boundaries from either composition extreme; any transition temperatures for $x=0.5--0.8$ are lower than we can measure. Magnetization isotherms evolve with composition, and associated hysteretic effects weaken with increasing x. The nonlinear susceptibility for $x=0.30$ shows structure, but does not diverge. The thermoremanent magnetization (TRM) is examined in detail for $x=0.30,$ 0.40, and 0.50. Its temperature dependence shows characteristic features, but does not follow any simple form. Systematic variation in the TRM with cooling field and composition is apparent. The time dependence of the TRM is fit using a stretched exponential decay form. Systematic variations in the fit parameters with temperature, cooling field, and composition emerge. For low to moderate temperatures, the TRM is found to scale according to $T{\mathrm{log}}_{10}(t/{\ensuremath{\tau}}_{0}),$ with ${\ensuremath{\tau}}_{0}\ensuremath{\approx}{10}^{\ensuremath{-}12}--{10}^{\ensuremath{-}13}\mathrm{s}.$ For $x=0.30$ and 0.50, strong and weak irreversibility lines are determined. The former conform better to a recent prediction for the short-range three-dimensional Ising spin glass, ${\ensuremath{\tau}}_{g}\ensuremath{\propto}{h}^{0.53},$ than to the DeAlmeida-Thouless mean-field form ${\ensuremath{\tau}}_{g}\ensuremath{\propto}{h}^{2/3};$ best-fit exponents are slightly less than 0.53. For the weak irreversibility lines, the dependence of ${\ensuremath{\tau}}_{g}$ on field is much weaker than the Gabay-Toulouse form ${\ensuremath{\tau}}_{g}\ensuremath{\propto}{h}^{2}.$ The presence of strong random anisotropy is a possible explanation. A monotonic decrease of ${T}_{s}$ with increasing x is found. A reentrant spin glass state still occurs for $x=0.30;$ for $x=0.40$ and 0.50, the spin glass transition is not reentrant. Irreversible effects are maximized in the $x=0.3--0.4$ region; they are absent for mixtures richer in manganese than cobalt.