80 research outputs found
(2R)-4-[(9H-Fluoren-9-ylmethoxy)carbonyl]-2-methylpiperazin-1-ium chloride
The synthesis of the title salt, C20H23N2O2
+·Cl−, was carried out with a precursor of known absolute configuration (R) and the X-ray analysis confirmed that the product retained the absolute configuration. In the crystal, the dominant packing motif is a chain running along [010] generated by N—H⋯Cl hydrogen bonding. C—H⋯O and C—H⋯Cl interactions are also observed
Self versus Environment Motion in Postural Control
To stabilize our position in space we use visual information as well as non-visual physical motion cues. However, visual cues can be ambiguous: visually perceived motion may be caused by self-movement, movement of the environment, or both. The nervous system must combine the ambiguous visual cues with noisy physical motion cues to resolve this ambiguity and control our body posture. Here we have developed a Bayesian model that formalizes how the nervous system could solve this problem. In this model, the nervous system combines the sensory cues to estimate the movement of the body. We analytically demonstrate that, as long as visual stimulation is fast in comparison to the uncertainty in our perception of body movement, the optimal strategy is to weight visually perceived movement velocities proportional to a power law. We find that this model accounts for the nonlinear influence of experimentally induced visual motion on human postural behavior both in our data and in previously published results
Recommended from our members
Cue properties change timing strategies in group movement synchronisation
To maintain synchrony in group activities, each individual within the group must continuously correct their movements to remain in time with the temporal cues available. Cues might originate from one or more members of the group. Current research suggests that when synchronising movements, individuals optimise their performance in terms of minimising variability of timing errors (asynchronies) between external cues and their own movements. However, the cost of this is an increase in the timing variability of their own movements. Here we investigate whether an individual’s timing strategy changes according to the task, in a group scenario. To investigate this, we employed a novel paradigm that positioned six individuals to form two chains with common origin and termination on the circumference of a circle. We found that participants with access to timing cues from only one other member used a strategy to minimise their asynchrony variance. In contrast, the participant at the common termination of the two chains, who was required to integrate timing cues from two members, used a strategy that minimised movement variability. We conclude that humans are able to flexibly switch timekeeping strategies to maintain task demands and thus optimise the temporal performance of their movements
The role of pro- and anti-inflammatory responses in silica-induced lung fibrosis
BACKGROUND: It has been generally well accepted that chronic inflammation is a necessary component of lung fibrosis but this concept has recently been challenged. METHODS: Using biochemical, histological, immunohistochemistry, and cellular analyses, we compared the lung responses (inflammation and fibrosis) to fibrogenic silica particles (2.5 and 25 mg/g lung) in Sprague-Dawley rats and NMRI mice. RESULTS: Rats treated with silica particles developed chronic and progressive inflammation accompanied by an overproduction of TNF-α as well as an intense lung fibrosis. Dexamethasone or pioglitazone limited the amplitude of the lung fibrotic reaction to silica in rats, supporting the paradigm that inflammation drives lung fibrosis. In striking contrast, in mice, silica induced only a limited and transient inflammation without TNF-α overproduction. However, mice developed lung fibrosis of a similar intensity than rats. The fibrotic response in mice was accompanied by a high expression of the anti-inflammatory and fibrotic cytokine IL-10 by silica-activated lung macrophages. In mice, IL-10 was induced only by fibrotic particles and significantly expressed in the lung of silica-sensitive but not silica-resistant strains of mice. Anti-inflammatory treatments did not control lung fibrosis in mice. CONCLUSION: These results indicate that, beside chronic lung inflammation, a pronounced anti-inflammatory reaction may also contribute to the extension of silica-induced lung fibrosis and represents an alternative pathway leading to lung fibrosis
Recommended from our members
Unified Structural Representation of the southern California crust and upper mantle
We present a new, 3D description of crust and upper mantle velocity structure in southern California implemented as a Unified Structural Representation (USR). The USR is comprised of detailed basin velocity descriptions that are based on tens of thousands of direct velocity (Vp, Vs) measurements and incorporates the locations and displacement of major fault zones that influence basin structure. These basin descriptions were used to developed tomographic models of crust and upper mantle velocity and density structure, which were subsequently iterated and improved using 3D waveform adjoint tomography. A geotechnical layer (GTL) based on Vs30 measurements and consistent with the underlying velocity descriptions was also developed as an optional model component. The resulting model provides a detailed description of the structure of the southern California crust and upper mantle that reflects the complex tectonic history of the region. The crust thickens eastward as Moho depth varies from 10 to 40 km reflecting the transition from oceanic to continental crust. Deep sedimentary basins and underlying areas of thin crust reflect Neogene extensional tectonics overprinted by transpressional deformation and rapid sediment deposition since the late Pliocene. To illustrate the impact of this complex structure on strong ground motion forecasting, we simulate rupture of a proposed M 7.9 earthquake source in the Western Transverse Ranges. The results show distinct basin amplification and focusing of energy that reflects crustal structure described by the USR that is not captured by simpler velocity descriptions. We anticipate that the USR will be useful for a broad range of simulation and modeling efforts, including strong ground motion forecasting, dynamic rupture simulations, and fault system modeling. The USR is available through the Southern California Earthquake Center (SCEC) website (http://www.scec.org)
Макрофагальная активность в коже больных псориазом при NB-UVB (311 нм) терапии
Досліджено 55 пацієнтів хворих на псоріаз. Пацієнти були розділені на 2 групи. Група 1 – 27
пацієнтів, які отримували тільки стандартне лікування і група 2 – 28 пацієнтів, які отримували стандартну
і NB-UVB терапію. NB-UVB призначалась 3 рази в тиждень, при цьому використовували стартову дозу 0,1-0,3 J/cm2
, середня кумулятивна доза від 30 до 60 J/cm2
. Рівень макрофагальної активності в біоптатах шкіри досліджували за допомогою імуногістохімічного методу на 1 і 21 добу. NB-UVB терапія призовдить до зниження рівня експресії CD68 – маркера макрофагів, більшою часткою якої є функціонально-активні клітини, що свідчить про адекватність імуної відповіді і зниження запальної реакції.There were researched 55 psoriasis patients. Patients were divided in two groups. Group 1 – 27
patients who received only standard therapy and Group 2 – 28 patients who received standard and NB-UVB
therapy. NB-UVB treatment was applied three times weekly. Starting UVB dose 0.1-0.3 J/cm2
, the mean
cumulative UVB dose was 42.0 J/cm2
. The level of macrophage activity in skin biopsy was investigated by an
immunohistochemical method on 1 and 21 days. NB-UVB therapy is linked to decline of level of CD68 expression with predominant of functionally active cells which testifies to adequacy of immune reactions and decline of
inflammatory reaction
Refined Kinematics of the Eastern California Shear Zone from GPS Observations, 1993-1998
Global Positioning System (GPS) results from networks spanning the Eastern California shear zone and adjacent Sierra Nevada block, occupied annually between 1993 and 1998, constrain plate margin kinematics. We use an elastic block model to relate GPS station velocities to long-term fault slip rate estimates. The model accounts for elastic strain accumulation on the San Andreas fault, as well as faults of the Eastern California shear zone. South of the Garlock fault, 14 mm/yr of dextral shear is distributed across the Eastern California shear zone. Some of this slip penetrates eastward into the Basin and Range, and a collective budget of 13 mm/yr is observed to the north at the latitude of Owens Lake. Model slip rates for two important faults, the Garlock and Owens Valley faults, significantly misfit geologic estimates. By referencing station velocities to stable North America we observe northward-increasing deformation east of our regional GPS network. At the latitude of Mojave Desert, however, some of this deformation is ascribed to elastic strain accumulation due to a locked San Andreas fault and thus does not represent additional fault-related, permanent deformation
Metamorphic evolution of exhumed middle to lower crustal rocks in the Mojave Extensional Belt, southern California, USA
The Waterman Metamorphic Complex of the central Mojave Desert was exposed as a consequence of early Miocene detachment‐dominated extension. However, it has evidence consistent with a more extensive geological history that involves collision of a crustal fragment(s), tectonic thickening by overthrusting and two periods of extension. The metamorphic complex contains granitoid intrusives and felsic mylonitic gneisses as well as polymetamorphic rocks that include marble, calc‐silicate, quartzite. mafic granulite, pyribolite, amphibolite, migmatite and biotite schist. The latter group of rocks was affected by an initial series of high‐grade metamorphic events (M1 and M2) and a localized lower grade overprint (M3). The initial metamorphism (M1) can be separated into two stages along its high‐grade P–T path: M1a, a granulite facies metamorphism at 800–850° C and 7.5–9 kbar and Mlb, an upper amphibolite facies overprint at 750–800° C and 10–12 kbar. M1a developed mineral assemblages and textures consistent with granulite facies conditions at a reduced activity of H2O and is associated with intense ductile deformation (D1) and minor local partial melting. M1b overprinted the granulite assemblages with a series of hydrous phases under conditions of increasing pressure and H2O activity and is accompanied by little or no deformation. M2 developed at lower pressures and temperatures (650–750° C, 4.5–5.5 kbar) and is distinguished by a second local overprint of hydrous phases that reflects an input of aqueous fluids probably associated with the intrusion of a series of granitic dykes and veins. Effects of M3 are confined to the Mitchel detachment zone, an anastomosing early Miocene detachment fault, and are characterized by local ductile/brittle deformation (D2) of the pre‐existing high‐grade rocks and granitoid intrusives and by the production of mylonites and mylonitic gneisses under greenschist facies conditions (300–350° C, 3–5 kbar). The initial overprint (M1a) represents metamorphism, devolatilization and minor partial melting of supracrustal rocks under granulite facies conditions as a consequence of tectonic and, possibly, magmatic thickening. The increasing pressure transition of M1a to M1b reflects a period of continued compressional tectonism, thrusting and influx of H2O, in part, locally related to crystallization of partial melts. The near isothermal decompression between M1b and M2 probably represents a pre‐112‐Ma extensional episode that may have been the result of a decompressional readjustment of a thickened crust. Following the initial extensional event, the metamorphic complex remained at depths of 10–17 km for at least 90 Ma until it was uplifted following Miocene extension. M3 develops locally in response to this second extensional period resulting from the early Miocene detachment faulting. Copyright © 1992, Wiley Blackwell. All rights reserve
Flexible coding of object motion in multiple reference frames by parietal cortex neurons
物体の動きに関与する柔軟な座標表現の脳機能を解明 --⾃他の動きを正確に判断する脳の仕組み--. 京都大学プレスリリース. 2020-06-22.Neurons represent spatial information in diverse reference frames, but it remains unclear whether neural reference frames change with task demands and whether these changes can account for behavior. In this study, we examined how neurons represent the direction of a moving object during self-motion, while monkeys switched, from trial to trial, between reporting object direction in head- and world-centered reference frames. Self-motion information is needed to compute object motion in world coordinates but should be ignored when judging object motion in head coordinates. Neural responses in the ventral intraparietal area are modulated by the task reference frame, such that population activity represents object direction in either reference frame. In contrast, responses in the lateral portion of the medial superior temporal area primarily represent object motion in head coordinates. Our findings demonstrate a neural representation of object motion that changes with task requirements
- …