Linear Extent Research Articles

Demonstrating Invariant Encoding of Shapes Using A Matching Judgment Protocol

Many theories have been offered to explain how the visual system registers, encodes, and recognizes the shape of an object. Some of the most influential assume that border lines and edges activate neurons in primary visual cortex, and these neurons encode the orientation, curvature, and linear extent of the shape as elemental cues. The present work challenges that assumption by showing that well-spaced dots can serve as effective shape cues. The experimental tasks drew on an inventory of unknown two-dimensional shapes, each being constructed as dots that marked the outer boundary, like an outline contour. A given shape was randomly picked from the inventory and was displayed only once as a target. The target shape was quickly followed by a low-density comparison shape that was derived from the target (matching) or from a different shape (non-matching). The respondent’s task was to provide a matching judgment, i.e. , deciding whether the comparison shape was the “same” or “different.” Clear evidence of non-chance decisions was found even when the matching shapes displayed only 5% of the number of dots in the target shapes. Visual encoding mechanisms allow a shape to be identified when it is displayed at various locations on the retina, or with rotation or changes in size. A number of hierarchical network (connectionist) models have been developed to accomplish this encoding step, and these models appear especially credible because they are inspired by the anatomy and physiology of the visual system. The present work demonstrates above-chance translation, rotation, and size invariance for unknown shapes that were seen only once. This is clearly at odds with connectionist models that require extensive training before a shape can be identified irrespective of location, rotation, or size.

Comparative evaluation of sealing ability of light cure glass ionomer cement and light cure composite as coronal sealing material: An in vitro study

Aim: To compare and evaluate the sealing ability of light cure composite and light cure GIC as coronal sealing materials. Materials and Methods: 30 extracted human teeth were divided into three experimental groups of 10 teeth each. The teeth in group I are obturated without coronal seal, teeth in group II are obturated with light cure GIC (3M ESPE VITREMER) as coronal seal and teeth in group III are obturated with light cure composite(3M ESPE filtek z250) as coronal seal, after removing 2mm of coronal gutta percha. These teeth (crown portion) are then suspended in methylene blue, sealed and kept for 72 hours, to observe the amount of dye penetration. After 72 hours teeth were removed, washed under running water, dried and sectioned longitudinally, separating buccal and lingual halves. The linear extent of dye penetration was measured from cavosurface margin of the access cavity to the most apical extent of dye penetration point. The length from the cavosurface margin to the apex of the tooth was also measured and percentage linear micro leakage was estimated. Statistical Analysis: Data was statistically analyzed using one-way ANOVA followed by Post-Hoc Multiple comparison (Bonferroni). Results: In the present study specimens in group I showed the maximum percentage of linear microleakage of 31.51 percent. The specimens in group II showed the minimal amount of linear micro leakage of 6.49 percent. Conclusion: It can be concluded coronal seal reduces the micro leakage, and light cure GIC has better coronal sealing ability.

Analyses between Reproductive Behavior, Genetic Diversity and Pythium Responsiveness in Zingiber spp. Reveal an Adaptive Significance for Hemiclonality.

Mode of reproduction is generally considered to have long-range evolutionary implications on population survival. Because sexual reproduction produces genetically diverse genotypes, this mode of reproduction is predicted to positively influence the success potential of offspring in evolutionary arms race with parasites (Red queen) whereas, without segregation and recombination, the obligate asexual multiplication may push a species into extinction due to the steady accumulation of deleterious mutations (Muller’s ratchet). However, the extent of linearity between reproductive strategies, genetic diversity and population fitness, and the contributions of different breeding strategies to population fitness are yet to be understood clearly. Genus Zingiber belonging to the pan-tropic family Zingiberaceae represents a good system to study contributions of different breeding behavior on genetic diversity and population fitness, as this genus comprises species with contrasting breeding systems. In this study, we analyzed breeding behavior, amplified fragment length polymorphism diversity and response to the soft-rot pathogen Pythium aphanidermatum in 18 natural populations of three wild Zingiber spp.: Z. neesanum, Z. nimmonii, and Z. zerumbet, together with the obligately asexual cultivated congener, ginger (Z. officinale). Ginger showed an exceptionally narrow genetic base, and adding to this, all the tested cultivars were uniformly susceptible to soft-rot. Concordant with the postulates of Muller’s ratchet, the background selection may be continuously pushing ginger into the ancestral state, rendering it inefficient in host-pathogen coevolution. Z. neesanum and Z. nimmonii populations were sexual and genetically diverse; however, contrary to Red Queen expectations, the populations were highly susceptible to soft-rot. Z. zerumbet showed a hemiclonal breeding behavior. The populations inhabiting forest understory were large and continuous, sexual and genetically diverse, but were susceptible, whereas populations inhabiting the revenue land were fragmented and monoclonal, but were resistant. It may be possible that, when genetic recombination becomes at a premium due to the genetic constraints imparted by habitat fragmentation or pathogen pressure, Z. zerumbet

Discovery of a fourth arc in Abell 2626 at 610 MHz with the GMRT: spectral properties and possibilities for the origin

Abstract We report the discovery of a fourth eastern arc (Arc E) towards the cool-core cluster Abell 2626 using 610 MHz Giant Metrewave Radio Telescope observations. Three arcs towards north, west and south were known from earlier works at 1400 MHz and proposed to have originated in precessing radio jets of the central active galactic nucleus. The 610–1400 MHz integrated spectral indices of the arcs are in the range 3.2–3.6 and the spectral index map shows uniform distribution along the lengths of the arcs. If associated with A2626, the arcs have linear extents in the range 79–152 kpc. The detection of Arc E favours the scenario in which a pair of bipolar precessing jets were active and halted to produce the arc system. Based on the morphological symmetry and spectral similarity, we indicate a possible role of gravitational lensing. Further, high-resolution low-frequency observations and measurements of the mass of the system are needed to disentangle the mystery of this source.

Porosity of maxillofacial silicone elastomers and microleakage pattern of the commercially pure Ti-silicone elastomer interface after hydrothermal cycling

Statement of problemDelamination of the maxillofacial silicone elastomer away from the commercially pure titanium (cpTi)-encapsulated magnets affects the long-term performance of the facial restoration. PurposeThe purposes of this in vitro study were to investigate the interfacial microleakage patterns of 2 maxillofacial silicone elastomers with cpTi when 3 different primers were used and to evaluate the porosity of the 2 elastomers tested. Material and methodsTo test the interfacial microleakage patterns of the 2 elastomers MDX4-4210 (EL1) and A-2006 (EL2) with cpTi when 3 metal primers, A-304 (PR1), A-320 bonding enhancer (PR2), Super-Bond C&B monomer (PR3), and ethyl-cyanoacrylate (Super Glue) were used, the bonded interfaces were observed using reflected light microscopy, and the percentage of the linear extent of leakage along the interface (%microleakage) was measured. High-resolution x-ray computed microtomography scanning was used to investigate the percentage of void volume fraction (%VF) for both silicone EL1 and EL2. The data were analyzed with 2-way ANOVA and post hoc tests (α=.05). ResultsNo statistically significant differences were found among the percentages of PR1, PR2, and PR3 microleakage, whereas ethyl-cyanoacrylate showed a statistically significant higher percentage of microleakage than either of the silicone elastomers (P<.001). EL1 medical grade elastomer groups have always had a statistically significantly higher percentage of microleakage than the EL2 platinum silicone elastomer groups (P<.001). For both elastomers, no statistically significant differences were found in %VF (P=.056). ConclusionsDifferences in mechanical properties, chemical composition, and manipulations during handling of the maxillofacial silicone elastomers can affect the linear microleakage along the cpTi-silicone elastomer bonding interface and the porosity of the silicone elastomer.

A STUDY OF BROADBAND FARADAY ROTATION AND POLARIZATION BEHAVIOR OVER 1.3–10 GHz IN 36 DISCRETE RADIO SOURCES

ABSTRACT We present a broadband polarization analysis of 36 discrete polarized radio sources over a very broad, densely sampled frequency band. Our sample was selected on the basis of polarization behavior apparent in narrowband archival data at 1.4 GHz: half the sample shows complicated frequency-dependent polarization behavior (i.e., Faraday complexity) at these frequencies, while half shows comparatively simple behavior (i.e., they appear Faraday simple). We re-observed the sample using the Australia Telescope Compact Array in full polarization, with 6 GHz of densely sampled frequency coverage spanning 1.3–10 GHz. We have devised a general polarization modeling technique that allows us to identify multiple polarized emission components in a source, and to characterize their properties. We detect Faraday complex behavior in almost every source in our sample. Several sources exhibit particularly remarkable polarization behavior. By comparing our new and archival data, we have identified temporal variability in the broadband integrated polarization spectra of some sources. In a number of cases, the characteristics of the polarized emission components, including the range of Faraday depths over which they emit, their temporal variability, spectral index, and the linear extent of the source, allow us to argue that the spectropolarimetric data encode information about the magneto-ionic environment of active galactic nuclei themselves. Furthermore, the data place direct constraints on the geometry and magneto-ionic structure of this material. We discuss the consequences of restricted frequency bands on the detection and interpretation of polarization structures, and the implications for upcoming spectropolarimetric surveys.

Control of the size of the coherence area in entangled twin beams

We study the effect of a change in size and spatial profile of the pump beam in an atomic-based four-wave mixing process on the size of the coherence area of the generated entangled twin beams. We perform experiments and develop a theoretical model to obtain a measure of the linear extent or ``radius'' of the coherence area from noise measurements of the twin beams as a function of transmission through a variable size slit. Our results show that an increase in the size of the pump reduces the size of the coherence area. More interestingly, we find that the use of a flat-top pump beam of the same size as a Gaussian pump beam leads to a reduction by a factor of more than 2 in the linear extent of the coherence area. This in turn leads to an increase by a factor of more than 4 in the number of spatial modes that make up the twin beams and a resolution enhancement of the entangled images that can be generated with the four-wave mixing process.

Threshold expansion of the three-particle quantization condition

We recently derived a quantization condition for the energy of three relativistic particles in a cubic box. Here we use this condition to study the energy level closest to the three-particle threshold when the total three-momentum vanishes. We expand this energy in powers of $1/L$, where $L$ is the linear extent of the finite volume. The expansion begins at ${\cal O}(1/L^3)$, and we determine the coefficients of the terms through ${\cal O}(1/L^6)$. As is also the case for the two-particle threshold energy, the $1/L^3$, $1/L^4$ and $1/L^5$ coefficients depend only on the two-particle scattering length $a$. These can be compared to previous results obtained using nonrelativistic quantum mechanics and we find complete agreement. The $1/L^6$ coefficients depend additionally on the two-particle effective range $r$ (just as in the two-particle case) and on a suitably defined threshold three-particle scattering amplitude (a new feature for three particles). A second new feature in the three-particle case is that logarithmic dependence on $L$ appears at $\mathcal O(1/L^6)$. Relativistic effects enter at this order, and the only comparison possible with the nonrelativistic result is for the coefficient of the logarithm, where we again find agreement. For a more thorough check of the $1/L^6$ result, and thus of the quantization condition, we also compare to a perturbative calculation of the threshold energy in relativistic $\lambda \phi^4$ theory, which we have recently presented. Here all terms can be compared and we find full agreement.

The extreme relativity of perception: A new contextual effect modulates human resolving power.

The authors report the discovery of a new effect of context that modulates human resolving power with respect to an individual stimulus. They show that the size of the difference threshold or the just noticeable difference around a standard stimulus depends on the range of the other standards tested simultaneously for resolution within the same experimental session. The larger this range, the poorer the resolving power for a given standard. The authors term this effect the range of standards effect (RSE). They establish this result both in the visual domain for the perception of linear extent, and in the somatosensory domain for the perception of weight. They discuss the contingent nature of stimulus resolution in perception and psychophysics and contrast it with the immunity to contextual influences of visually guided action.

ρandK*resonances on the lattice at nearly physical quark masses andNf=2

Working with a pion mass $m_\pi \approx 150$ MeV, we study $\pi\pi$ and $K\pi$ scattering using two flavours of non-perturbatively improved Wilson fermions at a lattice spacing $a\approx 0.071$ fm. Employing two lattice volumes with linear spatial extents of $N_s=48$ and $N_s=64$ points and moving frames, we extract the phase shifts for p-wave $\pi\pi$ and $K\pi$ scattering near the $\rho$ and $K^*$ resonances.Comparing our results to those of previous lattice studies, that used pion masses ranging from about 200 MeV up to 470 MeV, we find that the coupling $g_{\rho\pi\pi}$ appears to be remarkably constant as a function of $m_{\pi}$.

Aggregation dynamics of rigid polyelectrolytes.

Similarly charged polyelectrolytes are known to attract each other and aggregate into bundles when the charge density of the polymers exceeds a critical value that depends on the valency of the counterions. The dynamics of aggregation of such rigid polyelectrolytes are studied using large scale molecular dynamics simulations. We find that the morphology of the aggregates depends on the value of the charge density of the polymers. For values close to the critical value, the shape of the aggregates is cylindrical with height equal to the length of a single polyelectrolyte chain. However, for larger values of charge, the linear extent of the aggregates increases as more and more polymers aggregate. In both the cases, we show that the number of aggregates decrease with time as power laws with exponents that are not numerically distinguishable from each other and are independent of charge density of the polymers, valency of the counterions, density, and length of the polyelectrolyte chain. We model the aggregation dynamics using the Smoluchowski coagulation equation with kernels determined from the molecular dynamics simulations and justify the numerically obtained value of the exponent. Our results suggest that once counterions condense, effective interactions between polyelectrolyte chains short-ranged and the aggregation of polyelectrolytes are diffusion-limited.

Mapping kiloparsec-scale structures in the extended H i disc of the galaxy UGC 000439 by H i 21-cm absorption

We study the properties of HI gas in the outer regions (~2r_25) of a spiral galaxy, UGC 00439 (z = 0.01769), using HI 21-cm absorption towards different components of an extended background radio source, J0041$-$0043 (z = 1.679). The radio source exhibits a compact core coincident with the optical quasar and two lobes separated by ~7 kpc, all at an impact parameter ~25 kpc. The HI 21-cm absorption detected towards the southern lobe is found to extend over ~2 kpc^2. The absorbing gas shows sub-kpc-scale structures with the line-of-sight velocities dominated by turbulent motions. Much larger optical depth variations over 4-7 kpc-scale are revealed by the non-detection of HI 21-cm absorption towards the radio core and the northern lobe, and the detection of NaI and CaII absorption towards the quasar. This could reflect a patchy distribution of cold gas in the extended HI disc. We also detect HI 21-cm emission from UGC 00439 and two other galaxies within ~150 kpc to it, that probably form an interacting group. However, no HI 21-cm emission from the absorbing gas is detected. Assuming a linear extent of ~4 kpc, as required to cover both the core and the southern lobe, we constrain the spin temperature <~300 K for the absorbing gas. The kinematics of the gas and the lack of signatures of any ongoing in situ star formation are consistent with the absorbing gas being at the kinematical minor axis and corotating with the galaxy. Deeper HI 21-cm observations would help to map in greater detail both the large- and small-scale structures in the HI gas associated with UGC 00439.

Reporting the greatest linear extent of ductal carcinoma in situ on needle core biopsy

Ductal carcinoma in situ (DCIS) of the breast is staged as pTis regardless of size; however, extent of DCIS correlates with local recurrence rates and likelihood of close or positive margins. As a result, DCIS extent influences patient management and is an important element in the College of American Pathologists tumor summary checklist for excision specimens. There are no recommendations regarding routine reporting of DCIS extent on needle core biopsy material, and to our knowledge, no systematic studies have evaluated the impact of reporting this in biopsy material. Consecutive cases of DCIS performed or reviewed at our institution were identified by pathology report search over a 7-year period. The greatest linear extent of DCIS on core biopsy was compared with the estimated extent in the excision. Of 241 total cases, there were 157 (65%) cases in which the DCIS extent on biopsy was smaller, 13 (5%) cases in which the sizes were equal, and 70 (29%) cases in which the biopsy size was greater, including 30 (12%) with no residual tumor on excision. Mean extent was greater on excision than on core biopsy (16.0 versus 5.7 mm; P < .0001); however, the opposite was seen when only small tumors (≤ 10 mm final size) were considered (4.5 versus. 3.6 mm; P = .0161). There was strong linear correlation (r = 0.9761; P < .0001) between the size change (excision size minus biopsy size) and final pathologic size. For accurate tumor summary checklist completion, DCIS extent should be reported for needle biopsy material, particularly in the setting of small tumors.

Curvature of the critical line on the plane of quark chemical potential and pseudoscalar meson mass for three-flavor QCD

We investigate the phase structure of three-flavor QCD in the presence of finite quark chemical potential $\mu/T\lesssim1.2$ by using the non-perturbatively $O(a)$ improved Wilson fermion action on lattices with a fixed temporal extent $N_{\rm t}=6$ and varied spatial linear extents $N_{\rm s}=8,10,12$. Especially, we focus on locating the critical end point that characterizes the phase structure, and extracting the curvature of the critical line on the $\mu$-$m_{\pi}$ plane. For Wilson-type fermions, the correspondence between bare parameters and physical parameters is indirect. Hence we present a strategy to transfer the bare parameter phase structure to the physical one, in order to obtain the curvature. Our conclusion is that the curvature is positive. This implies that, if one starts from a quark mass in the region of crossover at zero chemical potential, one would encounter a first-order phase transition when one raises the chemical potential.

Observation of geometry-dependent conductivity in two-dimensional electron systems

We report electrical conductivity $\ensuremath{\sigma}$ measurements on a range of two-dimensional electron gases (2DEGs) of varying linear extent. Intriguingly, at low temperatures ($T$) and low carrier density (${n}_{\mathrm{s}}$) we find the behavior to be consistent with $\ensuremath{\sigma}\ensuremath{\sim}{L}^{\ensuremath{\alpha}}$, where $L$ is the length of the 2DEG along the direction of transport. Importantly, such scale-dependent behavior is precisely in accordance with the scaling hypothesis of localization [Abrahams et al., Phys. Rev. Lett. 42, 673 (1979)] which dictates that in systems where the electronic wave function $\ensuremath{\xi}$ is localized, $\ensuremath{\sigma}$ is not a material-specific parameter but depends on the system dimensions. From our data we are able to construct the ``$\ensuremath{\beta}$ function'' $\ensuremath{\equiv}(h/{e}^{2})dln\ensuremath{\sigma}/dlnL$ and show this to be strongly consistent with theoretically predicted limiting values. These results suggest, remarkably, that the electrons in the studied 2DEGs preserve phase coherence over lengths $\ensuremath{\sim}10\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{m}$. This suggests the utility of the 2DEGs studied towards applications in quantum information as well as towards fundamental investigations into many-body localized phases.

Инновационный подход к построению опорных геодезических сетей линейных объектов

Abstract: An innovative concept of constructing geodetic control networks at the stage of engineering surveys for the design and construction of linear facilities large extent on the widespread use of continuously operating reference base stations is outlined. The coordinates of them are defined in the same for the whole linear object of the coordinate space. To minimize the distortion of angles and distances in the depiction of the earth’s surface on topographic plans rectangular coordinate system on a plane oblique cylindrical Mercator projection in the version by Khotin is offered. The Central line of the projection is proposed to set so that the distortion of the scale along the route was presented in small quantities which in practice can be neglected. The heights of the points are requested to be obtained from the conversion of the spatial geodetic coordinates based on local models of exactly quasigeoid heights. The technique of constructing a local model of the anomalies of the altitudes along the route of the object was shown.

Cytologic findings in stratified mucin-producing intraepithelial lesion of the cervix: A report of 34 cases.

Stratified mucin-producing intraepithelial lesion (SMILE) is an uncommon variant of in situ carcinoma of the cervix. This study aimed to identify the cytologic features of SMILE since these have not been well documented previously. The study group comprised 34 consecutive cases of SMILE encountered at a single institution in which a corresponding Papanicolaou smear, taken up to 12 months before histologic diagnosis, was available for review. The presence of associated cervical neoplastic lesions including cervical intraepithelial neoplasia (CIN), adenocarcinoma in situ (AIS), and invasive carcinoma was recorded. The linear extent and distribution of the SMILEs was also noted. Most Pap smears had been reported to show possible or definite high-grade CIN although 3 cases reported the presence of a high-grade glandular abnormality. No case had a prospective cytologic diagnosis of SMILE. Histology revealed concurrent CIN and/or AIS in all cases, and 1 specimen (3%) showed invasive adenocarcinoma. Following smear review, 23 of the 31 cases that included endocervical material showed recurrent cytologic features that appeared consistent with SMILE. These included three dimensional cell clusters with nuclear stratification and crowding, mild nuclear atypia, cytoplasmic vacuoles, mitotic figures, and apoptosis. SMILE is almost always associated with additional HPV-related neoplastic lesions although only one patient (3%) had invasive carcinoma, a lower rate than recorded in other studies. Consistent cytologic features associated with SMILE were identified but these were relatively subtle. However, increased awareness of these features may permit prospective diagnosis and this could influence patient management.

Charmed baryon spectroscopy and light flavor symmetry from lattice QCD

We determine the ground state and first excited state masses of singly and doubly charmed spin 1/2 and 3/2 baryons with positive and negative parity. Configurations with $N_f=2+1$ non-perturbatively improved Wilson-clover fermions were employed, with the same quark action also being used for the valence quarks, including the charm. The spectrum is calculated for pion masses in the range $M_\pi \sim 259-460$ MeV at a lattice spacing $a\sim 0.075$ fm. Finite volume effects are studied comparing lattices with two different linear spatial extents ($1.8\,{\rm fm}$ and $2.4\,{\rm fm}$). The physical point is approached from the SU(3) limit keeping the flavour averaged light quark mass fixed. The baryon masses are extrapolated using expansions in the strange-light quark mass difference. Most particles fall into the expected SU(3) multiplets with well constrained extrapolations, the exceptions having a possibly more complex internal structure. Overall agreement is found with experiment for the masses and splittings of the singly charmed baryons. As part of the calculation an analysis of the lower lying charmonium, $D$ and $D_s$ spectra was performed in order to assess discretisation errors. The gross spectra are reproduced, including the $D^*_{s0}$, $D_{s1}$ and $D_1$ mesons, while at this single lattice spacing hyperfine splittings come out $10-20$ MeV too low.

Impregnation with Microcrystalline Wax to Improve Rosewood Dimensional Stability and Surface Hardness

Air-dried rosewood (Aniba rosaeodora) samples with sizes of 50 mm (length) by 50 mm (width) by 20 mm (thickness) were pretreated with NaOH to increase their permeability. The specimens were then impregnated with microcrystalline wax at a temperature of 100 °C to obtain various weight gains at four treatment durations. After impregnation, the swelling and shrinkage extents and surface hardness of the rosewood were measured. The results showed that, compared with untreated specimens, the linear swelling extent, volumetric swelling extent, and linear shrinkage extent of the impregnated specimens decreased by 75.23%, 59.85%, and 80.70%, respectively, and the surface hardness of the treated specimens increased by 43.36%. The impregnation with wax significantly increased the dimensional stability and surface hardness of the rosewood.

An analysis of the halo and relic radio emission from Abell 3376 from Murchison Widefield Array observations

We have carried out multiwavelength observations of the near-by ($z=0.046$) rich, merging galaxy cluster Abell 3376 with the Murchison Widefield Array (MWA). As a part of the GaLactic and Extragalactic All-sky MWA survey (GLEAM), this cluster was observed at 88, 118, 154, 188 and 215 MHz. The known radio relics, towards the eastern and western peripheries of the cluster, were detected at all the frequencies. The relics, with a linear extent of $\sim$ 1 Mpc each, are separated by $\sim$ 2 Mpc. Combining the current observations with those in the literature, we have obtained the spectra of these relics over the frequency range 80 -- 1400 MHz. The spectra follow power laws, with $\alpha$ = $-1.17\pm0.06$ and $-1.37\pm0.08$ for the west and east relics, respectively ($S \propto \nu^{\alpha}$). Assuming the break frequency to be near the lower end of the spectrum we estimate the age of the relics to be $\sim$ 0.4 Gyr. No diffuse radio emission from the central regions of the cluster (halo) was detected. The upper limit on the radio power of any possible halo that might be present in the cluster is a factor of 35 lower than that expected from the radio power and X-ray luminosity correlation for cluster halos. From this we conclude that the cluster halo is very extended ($>$ 500 kpc) and/or most of the radio emission from the halo has decayed. The current limit on the halo radio power is a factor of ten lower than the existing upper limits with possible implications for models of halo formation.