Rapid chromosome territory relocation by nuclear motor activity in response to serum removal in primary human fibroblasts

This article has been made available through the Brunel Open Access Publishing Fund.Background: Radial chromosome positioning in interphase nuclei is nonrandom and can alter according to developmental, differentiation, proliferation, or disease status. However, it is not yet clear when and how chromosome repositioning is elicited. Results: By investigating the positioning of all human chromosomes in primary fibroblasts that have left the proliferative cell cycle, we have demonstrated that in cells made quiescent by reversible growth arrest, chromosome positioning is altered considerably. We found that with the removal of serum from the culture medium, chromosome repositioning took less than 15 minutes, required energy and was inhibited by drugs affecting the polymerization of myosin and actin. We also observed that when cells became quiescent, the nuclear distribution of nuclear myosin 1ß was dramatically different from that in proliferating cells. If we suppressed the expression of nuclear myosin 1ß by using RNA-interference procedures, the movement of chromosomes after 15 minutes in low serum was inhibited. When high serum was restored to the serum-starved cultures, chromosome repositioning was evident only after 24 to 36 hours, and this coincided with a return to a proliferating distribution of nuclear myosin 1ß. Conclusions: These findings demonstrate that genome organization in interphase nuclei is altered considerably when cells leave the proliferative cell cycle and that repositioning of chromosomes relies on efficient functioning of an active nuclear motor complex that contains nuclear myosin 1ß.Brunel Open Access Publishing Fun

A note on the Krone deposition equation and significance of floc aggregation

For modeling the rate of deposition of cohesive flocs in estuaries the Krone equation is extensively used. It was derived from flume experiments on muddy sediment from the San Francisco Bay, and is applicable to low suspended sediment concentration environments in which shear-induced aggregation - the growth and break up of flocs - has a limited role. It is shown that the use of this equation can lead to erroneous estimates of the mass deposition flux at typically higher estuarine concentrations. Krone's own experimental data permit the development of a more general equation accounting for the effects of concentration and turbulent shear rate on aggregation. These effects are dramatically observed in a deposition test in which a wire mesh was inserted in the flow to change the turbulent shearing rate and increase deposition. Even with the inclusion of aggregation effect in the general equation, field-based observations from San Francisco Bay suggest that typical flumes generally may not meet the space and time scaling requirements for field application of laboratory data. Thus, although the Krone equation should be eschewed in favor of the general equation, interpretations of model-predicted deposition rate must not be accepted without robust field-based verification. © 2014

Persistent reshaping of cohesive sediment towards stable flocs by turbulence.

Cohesive sediment forms flocs of various sizes and structures in the natural turbulent environment. Understanding flocculation is critical in accurately predicting sediment transport and biogeochemical cycles. In addition to aggregation and breakup, turbulence also reshapes flocs toward more stable structures. An Eulerian-Lagrangian framework has been implemented to investigate the effect of turbulence on flocculation by capturing the time-evolution of individual flocs. We have identified two floc reshaping mechanisms, namely breakage-regrowth and restructuring by hydrodynamic drag. Surface erosion is found to be the primary breakup mechanism for strong flocs, while fragile flocs tend to split into fragments of similar sizes. Aggregation of flocs of sizes comparable to or greater than the Kolmogorov scale is modulated by turbulence with lower aggregation efficiency. Our findings highlight the limiting effects of turbulence on both floc size and structure

Neural correlates of attention and streaming in a perceptually multistable auditory illusion

In a complex acoustic environment, acoustic cues and attention interact in the formation of streams within the auditory scene. In this study, a variant of the “octave illusion” [Deutsch (1974). Nature 251, 307–309] was used to investigate the neural correlates of auditory streaming, and to elucidate the effects of attention on the interaction between sequential and concurrent sound segregation in humans. By directing subjects’ attention to different frequencies and ears, it was possible to elicit several different illusory percepts with the identical stimulus. The first experiment tested the hypothesis that the illusion depends on the ability of listeners to perceptually stream the target tones from within the alternating sound sequences. In the second experiment, concurrent psychophysical measures and electroencephalography recordings provided neural correlates of the various percepts elicited by the multistable stimulus. The results show that the perception and neural correlates of the auditory illusion can be manipulated robustly by attentional focus and that the illusion is constrained in much the same way as auditory stream segregation, suggesting common underlying mechanisms

Numerical Algebraic Geometry: A New Perspective on String and Gauge Theories

The interplay rich between algebraic geometry and string and gauge theories has recently been immensely aided by advances in computational algebra. However, these symbolic (Gr\"{o}bner) methods are severely limited by algorithmic issues such as exponential space complexity and being highly sequential. In this paper, we introduce a novel paradigm of numerical algebraic geometry which in a plethora of situations overcomes these short-comings. Its so-called 'embarrassing parallelizability' allows us to solve many problems and extract physical information which elude the symbolic methods. We describe the method and then use it to solve various problems arising from physics which could not be otherwise solved.Comment: 36 page

Primary intraocular lymphoma.

Primary intraocular lymphoma (PIOL) is an ocular malignancy that is a subset of primary central system lymphoma (PCNSL). Approximately one-third of PIOL patients will have concurrent PCNSL at presentation, and 42-92% will develop PCNSL within a mean of 8-29 months. Although rare, the incidence has been rising in both immunocompromised and immunocompetent populations. The majority of PIOL is diffuse large B-cell lymphoma, though rare T-cell variants are described. Recently, PIOL has been classified by main site of involvement in the eye, with vitreoretinal lymphoma as the most common type of ocular lymphoma related to PCNSL. Diagnosis remains challenging for ophthalmologists and pathologists. PIOL can masquerade as noninfectious or infectious uveitis, white dot syndromes, or occasionally as other neoplasms such as metastatic cancers. Laboratory diagnosis by cytology has been much aided by the use of immunocytochemistry, flow cytometry, biochemical finding of interleukin changes (IL10:IL6 ratio > 1), and cellular microdissection with polymerase chain reaction amplification for clonality. Use of several tests improves the diagnostic yield. Approaches to treatment have centered on systemic methotrexate-based chemotherapy, often with cytarabine (Ara-C) and radiotherapy. Use of intravitreal chemotherapy with methotrexate (0.4 mg/0.1 mL) is promising in controlling ocular disease, and intravitreal rituximab (anti-CD20 monoclonal antibody) has also been tried. Despite these advances, prognosis remains poor

EVALUATION OF THE EFFICACY AND SAFETY OF 0.05% HALOBETASOL PROPIONATE OINTMENT AND 0.05% CLOBETASOL PROPIONATE OINTMENT IN CHRONIC, LOCALIZED PLAQUE PSORIASIS

Psoriasis is a common, chronic, inflammatory, multisystem disease involving the skin and joints. It accounts for 2.3% of the total dermatology outpatients in India.  Corticosteroids have an important role in skin diseases because of their anti-inflammatory, immunosuppressive, and anti-proliferative effects on the keratinocytes.Topical corticosteroids are commonly used in the management of psoriasis and other inflammatory skin disorders. Clobetasol 0.05% ointment and halobetasol 0.05% ointment are synthetic class I super-potent topical corticosteroids with anti-inflammatory, anti-pruritic and vasoconstrictive properties commonly prescribed for the treatment of psoriasis. The current study conducted in 202 patients from 6 centers showed a significant reduction in LPSI scores at end of treatment. The physician's global evaluation rating at end of treatment of almost total clearing of lesion (Grade 4) was reported in 19.2% and 32% patients, marked improvement (Grade 3) in 47.5% and 50.5%, moderate improvement (Grade 2) in 30.3% and 17.5% and mild improvement (Grade 1) in 3% and 0% for Clobetasol and Halobetasol groups respectively. The difference between the two groups for physicians' global evaluation was found to be statistically significant (p=0.019). 19.2% and 27.2% patients in Clobetasol and Halobetasol respectively, showed >75% improvement in photographic assessment (p=0.521).  There was a significant difference in the cosmetic acceptability (p=0.042) & in the ease of application (p=0.019) between the two groups.  No significant difference was found in serum cortisol levels, in both groups (p=0.074).Therefore this study reaffirms that halobetasol has better efficacy and good tolerability profile compared to clobetasol

Synthesis of Substituted Pyrimidine Derivatives and Evaluation of their Antimicrobial Activity

ABSTRACT Keto group of cyano pyridine moiety have been treated with various aromatic aldehydes to give corresponding chalcones. The Chalcones have been reacted with urea and thiourea to get corresponding novel oxopyrimidines and thiopyrimidines, the structure of all newly synthesized compounds were confirmed by spectral analysis. The synthesized compounds were evaluated for their antimicrobial activity. All the synthesized pyrimidine compounds have show good to moderate antimicrobial activity

Co3O4 Nanocrystals on Graphene as a Synergistic Catalyst for Oxygen Reduction Reaction

Catalysts for oxygen reduction and evolution reactions are at the heart of key renewable energy technologies including fuel cells and water splitting. Despite tremendous efforts, developing oxygen electrode catalysts with high activity at low costs remains a grand challenge. Here, we report a hybrid material of Co3O4 nanocrystals grown on reduced graphene oxide (GO) as a high-performance bi-functional catalyst for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). While Co3O4 or graphene oxide alone has little catalytic activity, their hybrid exhibits an unexpected, surprisingly high ORR activity that is further enhanced by nitrogen-doping of graphene. The Co3O4/N-doped graphene hybrid exhibits similar catalytic activity but superior stability to Pt in alkaline solutions. The same hybrid is also highly active for OER, making it a high performance non-precious metal based bi-catalyst for both ORR and OER. The unusual catalytic activity arises from synergetic chemical coupling effects between Co3O4 and graphene.Comment: published in Nature Material