2,150 research outputs found
Evidence That Luminant and Equiluminant Motion Signals Are Integrated by Directionally Selective Mechanisms
Three experiments tested whether motion information for nonequiluminant (luminant) and equiluminant dots affects direction judgments when both types of stimuli are moving simultaneously in the same display. The motion directions for the two sets of dots were manipulated to produce four direction differences (0Β°, 30Β°, 60Β°, and 90Β°). The equiluminant dots were moved in a perfectly correlated fashion, but the percentage of correlated motion for the luminant dots was varied. When subjects judged whether the directions of the equiluminant and luminant dots were the same or different, performance for the conditions with 0Β°, 60Β°, and 90Β° difference improved as the percentage of correlated luminant motion increased. The same result occurred for a control display that contained two sets of luminant dots. However, for the 30Β° difference, performance was at chance level for the control display, but dropped below chance for the equiluminant - luminant display. When subjects indicated just the direction of the luminant dots, judgments were not affected by equiluminant motion. Judgments for the equiluminant dots also were accurate, except for the conditions with 30Β° difference; these responses were biased by the luminant motion, indicating some form of motion capture. The interactive effects are discussed in terms of a directionally selective mechanism that combines equiluminant and luminant motion signals
Non-linear rheology of active particle suspensions: Insights from an analytical approach
We consider active suspensions in the isotropic phase subjected to a shear
flow. Using a set of extended hydrodynamic equations we derive a variety of
{\em analytical} expressions for rheological quantities such as shear viscosity
and normal stress differences. In agreement to full-blown numerical
calculations and experiments we find a shear thickening or -thinning behaviour
depending on whether the particles are contractile or extensile. Moreover, our
analytical approach predicts that the normal stress differences can change
their sign in contrast to passive suspensions.Comment: 11 pages, 10 figures, appear in PR
50 Years of Activist Scholarship Selected Proceedings of the 2022 Meeting of the National Association for Chicana and Chicano Studies
Hydrodynamic length-scale selection in microswimmer suspensions
A universal characteristic of mesoscale turbulence in active suspensions is the emergence of a typical vortex length scale, distinctly different from the scale invariance of turbulent high-Reynolds number flows. Collective length-scale selection has been observed in bacterial fluids, endothelial tissue, and active colloids, yet the physical origins of this phenomenon remain elusive. Here, we systematically derive an effective fourth-order field theory from a generic microscopic model that allows us to predict the typical vortex size in microswimmer suspensions. Building on a self-consistent closure condition, the derivation shows that the vortex length scale is determined by the competition between local alignment forces, rotational diffusion, and intermediate-range hydrodynamic interactions. Vortex structures found in simulations of the theory agree with recent measurements in Bacillus subtilis suspensions. Moreover, our approach yields an effective viscosity enhancement (reduction), as reported experimentally for puller (pusher) microorganisms
Ising-like critical behavior of vortex lattices in an active fluid
Turbulent vortex structures emerging in bacterial active fluids can be
organized into regular vortex lattices by weak geometrical constraints such as
obstacles. Here we show, using a continuum-theoretical approach, that the
formation and destruction of these patterns exhibit features of a continuous
second-order equilibrium phase transition, including long-range correlations,
divergent susceptibility, and critical slowing down. The emerging vorticity
field can be mapped onto a two-dimensional (2D) Ising model with
antiferromagnetic nearest-neighbor interactions by coarse-graining. The
resulting effective temperature is found to be proportional to the strength of
the nonlinear advection in the continuum model
Disruption of a Yeast ADE6 Gene Homolog in Ustilago maydis
A putative homolog of the Sacharromyces cereviseae ADE6 and Escherichia coli purL genes is identified near a multigenic complex, which contains two genes, sid1 and sid2, involved in a siderophore biosynthetic pathway inUstilago maydis. The putative ADE6 homolog was mutated by targeted gene disruption. The resulting mutant strains demonstrated a requirement for exogenous adenine, indicating that the U. maydis ade6 homolog is required for purine biosynthesis
Clinical impact of MDR1-expression in testicular germ cell cancer
Aim: The multidrug resistance protein 1 (MDR1, P-gp, p-170) is a membrane glycoprotein that acts as an energy-dependent drug efflux pump. In various malignancies its expression is associated with resistance to diverse cytostatic drugs, and therefore predicts resistance to systemic treatment. The aim of this study was to investigate the prognostic value of MDR1 expression in primary tumor tissue to predict necrosis or viable cancer in residual tumor masses after systemic chemotherapy for advanced testicular germ cell cancer. Materials and Methods: Out of 77 patients, histopathological characteristics of primary testicular cancer specimens and retroperitoneal lymph node dissection (RPLND) samples following chemotherapy were available from 72 and all 77 patients, respectively. Moreover, MDR1 expression was determined by immunohistochemistry in 47 primary tumors and corresponding 73 RPLND sections. Results: After chemotherapy and subsequent RPLND, the examination of residual tumor masses revealed that mature teratoma and active viable tumor were predominantly found in patients with non-seminoma (NSGCT; p = 0.048), especially in those with containing mature teratoma (p = 0.001). Moreover, using univariate analysis the expression of MDR1 in the primary testicular tumor predicted viable tumor/teratoma residues in RPLND sections (p = 0.003). However, in multivariate analysis including the tumorsβ histological subtype, MDR1 expression alone failed to reach statistical significance as an independent prognostic marker for residual vital tumor (p β₯ 0.16). Conclusions: With the limited number of patients given, the correlation between MDR1 expression in primary testis cancer and active residual retroperitoneal disease after chemotherapy failed to reach statistical significance as in independent marker. Therefore, up to now routine MDR1 staining of testicular germ cell cancer samples should not be performed in clinical practice. However, as there was a clear trend, a larger number of patients suffering from metastatic non-seminomas should be studied, as MDR1 expression might have significant prognostic value in this particular subgroup of patients.ΠΠ΅Π»ΠΎΠΊ 1 ΠΌΠ½ΠΎΠΆΠ΅ΡΡΠ²Π΅Π½Π½ΠΎΠΉ Π»Π΅ΠΊΠ°ΡΡΡΠ² Π΅Π½Π½ΠΎΠΉ ΡΡΡΠΎΠΉΡΠΈΠ² ΠΎΡΡΠΈ (MDR1, P-gp, p-170) β ΡΡΠΎ ΠΌΠ΅ΠΌΠ±ΡΠ°Π½Π½ΡΠΉ Π³Π»ΠΈΠΊΠΎΠΏΡΠΎΡΠ΅ΠΈΠ½, ΡΡΠ½ΠΊΡΠΈΠΎΠ½ΠΈΡΡΡΡΠΈΠΉ ΠΊΠ°ΠΊ ΡΠ½Π΅ΡΠ³ΠΎΠ·Π°Π²ΠΈΡΠΈΠΌΡΠΉ Π½Π°ΡΠΎΡ. ΠΡΠΈ ΡΠ°Π·Π» ΠΈΡΠ½ΡΡ
ΡΠΎ ΡΠΌΠ°Ρ
ΠΎΠΏΡΡ
ΠΎΠ»Π΅ΠΉ Π΅Π³ΠΎ ΡΠΊΡΠΏΡ Π΅ ΡΡΠΈΡ ΡΠ²ΡΠ·Π°Π½Π° Ρ ΡΡΡΠΎΠΉΡΠΈΠ² ΠΎ ΡΡΡΡ ΠΎΠΏΡΡ
ΠΎΠ»ΠΈ ΠΊ
ΡΠ°Π·Π»ΠΈΡΠ½ΡΠΌ ΡΠΈΡΠΎΡΡΠ°ΡΠΈΠΊΠ°ΠΌ, ΡΡΠΎ ΠΌΠΎΠΆΠ΅Ρ Π±ΡΡΡ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΎ Π΄Π»Ρ Π²ΡΠ±ΠΎΡΠ° ΡΠΈΠΏΠ° ΡΠ΅ΡΠ°ΠΏΠΈΠΈ. Π¦Π΅Π»Ρ ΡΠ°Π±ΠΎΡΡ β ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ ΠΏΡΠΎΠ³Π½ΠΎΡΡΠΈ-
ΡΠ΅ΡΠΊΠΎΠΉ Π·Π½Π°ΡΠΈΠΌΠΎΡΡΠΈ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ MDR1 Π² ΡΠΊΠ°Π½ΠΈ ΠΏΠ΅ ΡΠ²ΠΈΡΠ½ΠΎΠΉ ΠΎΠΏΡΡ
ΠΎΠ»ΠΈ Π΄Π»Ρ ΠΎΡΠ΅Π½ΠΊΠΈ Π²ΠΎΠ·ΠΌΠΎ ΠΆΠ½ΠΎΡΡΠΈ ΡΠ°Π· Π²ΠΈΡΠΈΡ Π½Π΅ΠΊΡΠΎΠ·Π° ΠΈΠ»ΠΈ ΡΠΎΡ
ΡΠ°Π½ Π΅ Π½ΠΈΡ
ΠΆΠΈΠ²ΡΡ
ΠΊΠ»Π΅ΡΠΎΠΊ Π² ΠΎΡΡΠ°ΡΠΎΡΠ½ΠΎΠΉ ΡΠΊΠ°Π½ΠΈ ΠΎΠΏΡΡ
ΠΎΠ»ΠΈ ΠΏΠΎΡΠ»Π΅ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΡ ΡΠΈΡΡΠ΅ΠΌΠ½ΠΎΠΉ Ρ
ΠΈΠΌΠΈΠΎΡΠ΅ΡΠ°ΠΏΠΈΠΈ Π½Π° ΠΏΠΎΠ·Π΄Π½ΠΈΡ
ΡΡΠ°Π΄ΠΈΡΡ
Π³Π΅ΡΠΌΠΈΠ½Π°ΡΠΈΠ²Π½ΡΡ
ΠΎΠΏΡΡ
ΠΎΠ»Π΅ΠΉ ΡΠΈΡΠΊΠ°. ΠΠ°ΡΠ΅ΡΠΈΠ°Π»Ρ ΠΈ ΠΌΠ΅ΡΠΎΠ΄Ρ: ΠΏΡΠΎ Π°Π½Π°Π»ΠΈΠ·ΠΈΡΠΎ Π²Π°Π½Ρ Π³ΠΈΡΡΠΎ ΠΏΠ°ΡΠΎΠ»ΠΎ Π³ΠΈΡΠ΅ΡΠΊΠΈΠ΅ Ρ
Π°ΡΠ°ΠΊΡ Π΅ ΡΠΈΡΡΠΈΠΊΠΈ ΠΏΠ΅ ΡΠ²ΠΈΡΠ½ΠΎ ΠΉ ΡΠ΅ ΡΡΠΈΠΊΡΠ»ΡΡΠ½ΠΎΠΉ
ΠΎΠΏΡΡ
ΠΎΠ»ΠΈ ΠΈ ΠΎΠ±ΡΠ°Π·ΡΠΎΠ², ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΡ
ΠΏΡΠΈ ΠΈΡΡΠ΅ΡΠ΅Π½ΠΈΠΈ ΡΠ΅ΡΡΠΎΠΏΠ΅ΡΠΈΡΠΎΠ½Π΅Π°Π»ΡΠ½ΡΡ
Π»ΠΈΠΌΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ·Π»ΠΎΠ² (RPLND) ΠΏΠΎΡΠ»Π΅ Ρ
ΠΈΠΌΠΈ ΠΎΡΠ΅ΡΠ°ΠΏΠΈΠΈ
72 ΠΈ 77 Π±ΠΎΠ» ΡΠ½ΡΡ
ΡΠΎΠΎΡΠ²Π΅ ΡΡΡΠ²Π΅Π½Π½ΠΎ. ΠΠΊΡΠΏΡ Π΅ΡΡΠΈΡ MDR1 ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΠ»ΠΈ ΠΈΠΌΠΌΡΠ½ ΠΎΠ³ΠΈΡΡ ΠΎΡ
ΠΈΠΌΠΈΡ Π΅ΡΠΊΠΈΠΌ ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ Π² 47 ΠΎΠ±ΡΠ°Π·ΡΠ°Ρ
ΠΏΠ΅ΡΠ²ΠΈΡΠ½ ΠΎΠΉ
ΠΎΠΏΡΡ
ΠΎΠ»ΠΈ ΠΈ ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΡΡΡΠΈΡ
73 ΡΡ RPLND. Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ: ΠΏΠΎΡΠ»Π΅ Ρ
ΠΈΠΌΠΈ ΠΎΡΠ΅ΡΠ°ΠΏΠΈΠΈ ΠΈ ΠΏΠΎΡΠ»Π΅Π΄ΡΡΡΠ΅ΠΉ RPLNDΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈ Π΅ ΠΎΡΡΠ°-
ΡΠΎΡΠ½ΡΡ
ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΡ
ΡΠΊΠ°Π½Π΅ΠΉ ΠΏΠΎΠΊΠ°Π·Π°Π»ΠΎ, ΡΡΠΎΠ·ΡΠ΅Π»Π°Ρ ΡΠ΅ΡΠ°ΡΠΎΠΌΠ° ΠΈ ΠΆΠΈΠ·Π½Π΅ΡΠΏΠΎΡΠΎΠ±Π½ΡΠ΅ ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΠ΅ ΠΊΠ»Π΅ΡΠΊΠΈ Π²ΡΡΠ² Π»ΡΡΡ ΠΏΡΠ΅ΠΈΠΌΡΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΎ
Ρ Π±ΠΎΠ»ΡΠ½ΡΡ
, Ρ ΠΊΠΎΡΠΎΡΡΡ
Π½Π΅ Π±ΡΠ»Π° ΠΎΠ±Π½Π°ΡΡΠΆΠ΅Π½Π° ΡΠ΅ΠΌΠΈΠ½ΠΎΠΌΠ° (NSGCT; p = 0,048), ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎ Ρ ΡΠ°ΠΊ ΠΎΠ²ΡΡ
, Ρ ΠΊΠΎΡΠΎΡΡΡ
Π±ΡΠ»Π° ΡΠ΅ΡΠ°ΡΠΎΠΌΠ° (p =
0,001). ΠΠΎΠ»Π΅Π΅ ΡΠΎΠ³ΠΎ, Π΄ Π°Π½Π½ΡΠ΅ ΠΎΠ΄Π½ΠΎ ΡΠ°ΠΊΡΠΎΡΠ½ΠΎΠ³ΠΎ Π°Π½Π°Π»ΠΈΠ·Π° ΠΏΠΎΠΊΠ°Π·Π°Π»ΠΈ, ΡΡΠΎ ΡΠΊΡΠΏΡ Π΅ ΡΡΠΈΡ MDR1 Π² ΡΠΊΠ°Π½ΠΈ ΠΏΠ΅ ΡΠ²ΠΈΡΠ½ΠΎ ΠΉ ΡΠ΅ ΡΡΠΈΠΊΡ Π»ΡΡΠ½ΠΎΠΉ ΠΎΠΏΡ-
Ρ
ΠΎΠ»ΠΈ ΠΌΠΎΠΆΠ΅Ρ ΡΠ»ΡΠΆΠΈΡΡ ΠΏΡΠΎΠ³Π½ΠΎΡΡΠΈΡ Π΅ΡΠΊΠΈΠΌ ΡΠ°ΠΊΡ ΠΎΡΠΎΠΌ ΡΠΎΡ
ΡΠ°Π½ Π΅Π½ΠΈΡ ΠΆΠΈΠ²ΡΡ
ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΡ
ΠΊΠ»Π΅ΡΠΎΠΊ ΡΡΠ΅Π·Π°Ρ
RPLND (p = 0,003). Π Π½Π°ΠΊ ΠΎ
ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ ΠΌΡΠ»ΡΡΠΈΡΠ°ΠΊΡΠΎΡΠ½ΠΎΠ³ΠΎ Π°Π½Π°Π»ΠΈΠ·Π°, Π² ΡΠΎΠΌ ΡΠΈΡΠ»Π΅ Ρ ΡΡΠ΅ΡΠΎΠΌ Π³ΠΈΡΡΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΏΠΎΠ΄ΡΠΈΠΏΠ° ΠΎΠΏΡΡ
ΠΎΠ»ΠΈ, ΠΏΠΎΠΊΠ°Π·Π°Π»ΠΎ, ΡΡΠΎ ΡΠΊΡΠΏΡ Π΅ ΡΡΠΈΡ
MDR1 Π½Π΅ ΠΈΠΌΠ΅Π΅Ρ ΡΠ°ΠΌΠΎΡΡΠΎΡΡΠ΅Π»ΡΠ½ΠΎΠΉ ΠΏΡΠΎΠ³Π½ΠΎΡΡΠΈΡΠ΅ΡΠΊΠΎΠΉ Π·Π½Π°ΡΠΈΠΌΠΎΡΡΠΈ Π΄Π»Ρ Π²ΡΡΠ²Π»Π΅Π½ΠΈΡ ΠΆΠΈΠ²ΡΡ
ΠΎΡΡΠ°ΡΠΎΡΠ½ΡΡ
ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΡ
ΠΊΠ»Π΅ΡΠΎΠΊ (p
0,16). ΠΡΠ²ΠΎΠ΄Ρ: Π²Π²ΠΈΠ΄Ρ Π½Π΅Π±ΠΎΠ»ΡΡΠΎ ΠΉΠ²ΡΠ±ΠΎΡΠΊΠΈΠ±ΠΎΠ»ΡΠ½ΡΡ
Π½Π΅ Π²ΡΡΠ² Π»Π΅Π½ΠΎ ΡΡΠ°ΡΠΈΡΡΠΈΡΠ΅ΡΠΊΠΈ Π·Π½Π°ΡΠΈΠΌΠΎΠΉΠΊΠΎΡΡΠ΅Π»ΡΡΠΈΠΈ ΠΌΠ΅ΠΆΠ΄Ρ ΡΠΊΡΠΏΡ Π΅ΡΡΠΈΠ΅ΠΉ MDR1
Π² ΠΏΠ΅ΡΠ²ΠΈΡΠ½ΠΎΠΉ ΠΎΠΏΡΡ
ΠΎΠ»ΠΈ ΡΠΈΡΠΊΠ° ΠΈ Π½Π°Π»ΠΈΡΠΈΠ΅ΠΌ Π°ΠΊΡΠΈΠ²Π½ΡΡ
ΡΠ΅Π·ΠΈΠ΄ΡΠ°Π»ΡΠ½ΡΡ
ΠΎΡΠ°Π³ΠΎΠ² ΠΏΠΎΡΠ°ΠΆΠ΅Π½ΠΈΡ Π² ΡΠ΅ΡΡΠΎΠΏΠ΅ΡΠΈΡΠΎΠ½Π΅Π°Π»ΡΠ½ΠΎΠΌ ΠΏΡΠΎΡΡΡΠ°Π½ΡΡΠ²Π΅. Π Ρ ΠΎ
ΠΆΠ΅ Π²ΡΠ΅ΠΌΡ, ΡΡΠΈΡΡΠ²Π°Ρ Π²ΡΡΠ²Π»Π΅Π½Π½ΡΡ ΡΠ΅Π½Π΄Π΅Π½ΡΠΈΡ, ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΡ MDR1, Π² ΠΊΠ°ΡΠ΅ΡΡΠ²Π΅ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΠ³ΠΎ ΠΏΡΠΎΠ³Π½ΠΎΡΡΠΈΡ Π΅ΡΠΊΠΎΠ³ΠΎ ΠΌΠ°ΡΠΊ Π΅ΡΠ°, ΠΈΠΌΠ΅Π΅Ρ
ΡΠΌΡΡΠ» ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°ΡΡ ΠΈΠΌΠ΅Π½Π½ΠΎ Ρ Π±ΠΎΠ»ΡΠ½ΡΡ
Ρ ΠΌΠ΅ΡΠ°ΡΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΠΌΠΈ ΠΎΠΏΡΡ
ΠΎΠ»ΡΠΌΠΈ, Π½Π΅ ΡΠ²Π»ΡΡΡΠΈΠΌΠΈΡΡ ΡΠ΅ΠΌΠΈΠ½ΠΎΠΌΠΎΠΉ
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