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Ripple marks formed in different sub-environments of a tidal flat are considered helpful in distinguishing such sub-environments from one another owing to the predominance of specific agencies that generate and stabilize these ripples. For example, ripple stabilized in tidal channels are dominated by tidal currents and those in estuarine settings are both wave and current dominated. In order to evaluate the possibility of using ripple morphology in distinguishing between such sub-environments, data on ripple index (RI) from an estuary and tidal channels were analyzed. These data were collected from the east coast of India that provides examples of open-coast tidal flats at Chandipur and 50 km north-east at Digha. It was found that they have overlapping morphological patterns as delineated from RI vs. the percentage fraction for each case of estuarine and tidal channels. So, while RI can broadly define environments, e.g., aeolian and water borne ripples, when it comes to separating wave from current ripples, a fair overlap is seen in tidal flat regions. On the other hand, grain-size study alone is insufficient for the purpose of delineating differences between such sub-environments. This is because it is seen in our analyses that while most estuarine sediments are finer than 3 on the Φ-scale and tidal channel sediments are coarser, much better sorted as well as mostly positively skewed, these values overlap such that a clear distinction cannot be achieved. Therefore, in order to distinguish between such sub-environments, we took into account both grain-size parameters associated with ripple marks and the corresponding RI values. A relative “distance” was calculated between pairs of samples based on RI, mean, sorting, skewness and kurtosis. In other words, this “distance” is a way to determine how similar two samples are in terms of their respective RI and grain-size parameters. A dissimilarity matrix was constructed which, in turn, was translated into a configuration of points in the Euclidean Space via Multidimensional Scaling (MDS). Four different “types” of measure of this “distance” were considered: Euclidean, Standard Euclidean, City Block and Minkowski (P=3). It was observed that the MDS plot based on City Block distance generated two distinct clusters of points for samples collected from estuary and tidal channels. A way forward is to employ Random Forest Analysis and test whether RI in conjunction with grain-size parameters may be used for classifying modern sediments or even rock samples representing paleo-environments as belonging to either estuarine or tidal channel setting.

The COVID-19 pandemic has affected the entire medical community including the thoracic surgical practice. The guidelines, consensus statements, and preliminary recommendations published by the thoracic surgeons so far have appreciated the importance of triage of patients with thoracic surgical diseases and multidisciplinary team (MDT) meeting. Delaying surgery or planning alternative treatment in patient care should be done by taking input from experts in thoracic specialties. The procedures that can be carried out in a hospital are based on the prevalence of COVID-19 patients within the hospital and availability of hospital resources. As a result, proper triaging, ensuring safety of patient and health care personnel, and optimal utilization of the available resources remain the cornerstone while fighting the COVID-19 pandemic. In this manuscript, we highlight these issues with respect to practice of thoracic surgery.

Background: oestrogen receptor positive/ human epidermal growth factor receptor positive (ER+/HER2+) breast cancers (BCs) are less responsive to endocrine therapy than ER+/HER2- tumours. Mechanisms underpinning the differential behaviour of ER+HER2+ tumours are poorly characterised. Our aim was to identify biomarkers of response to 2 weeks’ presurgical AI treatment in ER+/HER2+ BCs. Methods: all available ER+/HER2+ BC baseline tumours (n=342) in the POETIC trial were gene expression profiled using BC360™ (NanoString) covering intrinsic subtypes and 46 key biological signatures. Early response to AI was assessed by changes in Ki67 expression and residual Ki67 at 2 weeks (Ki67 2wk). Time-To-Recurrence (TTR) was estimated using Kaplan-Meier methods and Cox models adjusted for standard clinicopathological variables. New molecular subgroups (MS) were identified using consensus clustering. Findings: HER2-enriched (HER2-E) subtype BCs (44.7% of the total) showed poorer Ki67 response and higher Ki67 2wk (p2wk. Five new MS that were associated with differential response to AI were identified. HER2-E had significantly poorer TTR compared to Luminal BCs (HR 2.55, 95% CI 1.14–5.69; p=0.0222). The new MS were independent predictors of TTR, adding significant value beyond intrinsic subtypes. Interpretation: our results show HER2-E as a standardised biomarker associated with poor response to AI and worse outcome in ER+/HER2+. HRD, TP53 mutational score and immune-tumour tolerance are predictive biomarkers for poor response to AI. Lastly, novel MS identify additional non-HER2-E tumours not responding to AI with an increased risk of relapse. Funding: Cancer Research UK (CRUK/07/015).

Introduction: The progress in the management of maintenance hemodialysis and renal transplant has led to longer survival and also increased incidence of delayed complications. One of its dreadful complications is central venous occlusion which needs a satisfactory management. Materials and Methods: Bilateral subclavian vein occlusion, innominate vein occlusion, or superior vena cava occlusion remains the most dreadful scenario for central venous stenosis and central venous obstruction (CVO) in dialysis patients. In these patients who are refractory to endovascular options, surgery must be considered. We hereby describe our experience of managing these complications by a novel surgery of draining the area proximal to CVO to the right atrium by reinforced Polytetrafluoroethylene graft. Results: Three of our patient's symptom relief, salvage of arteriovenous fistula, and primary graft patency (mean – 20 months) were achieved satisfactorily. No postoperative mortality or no severe morbidity noted. Anticoagulation orally used up to 3 months of operation. One patient had graft occlusion and mild symptom recurrence. Conclusions: All the current endovascular options for CVO in dialysis patients are prone to recur. Extra-anatomic central venous bypass grafting draining into right atrial appendage is a novel management to relieve the complications. A satisfactory conduit with long-term patency and minimum thrombotic complications is still not available. Randomized control trials with long-term follow-up are needed to develop appropriate treatment algorithms.

Stress-activated and mitogen-activated protein kinases (MAPKs) regulate gene expression by post-translational modifications of transcription factors. Elk-1, a transcription factor that regulates the expression of immediate early genes, is amenable to regulation by all the three mammalian MAPKs. In the present report, using inhibitors specific for different MAPK pathways, we show that during exposure of HeLa cells to heat stress, Elk-1 is SUMOylated with SUMO1 by p38 MAPK pathway-dependent mechanisms. Elk-1-phosphorylation levels were significantly reduced under similar conditions. We also show that transcriptional activity of Elk-1 as assessed by luciferase reporter expression and qPCR estimation of the expression of genes regulated by Elk-1 was downregulated upon exposure to heat stress; this downregulation was reversed when heat exposure was performed in the presence of either SB203580 (p38 MAPK inhibitor) or ginkgolic acid (inhibitor of SUMOylation). Elk-1 induced transcription is also regulated by PIAS2 which acts as a coactivator upon the activation of extracellular signal-regulated kinases (ERKs) and as a corepressor upon its phosphorylation by p38 MAPK. Since heat stress activates the p38 MAPK pathway, we determined if PIAS2 was phosphorylated in heat-stressed HeLa cells. Our studies indicate that in HeLa cells exposed to heat stress, PIAS2 is phosphorylated by p38 MAPK pathway-dependent mechanisms. Collectively, the results presented demonstrate that in heat-stressed HeLa cells, p38 MAPK pathway-dependent SUMOylation of Elk-1 and phosphorylation of PIAS2 correlate with the downregulation of transactivation by Elk-1. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s12192-019-00974-4) contains supplementary material, which is available to authorized users.

Exposure to heat stress (HS) elicits systemic and cellular response in experimental animals and humans. The current study was undertaken to determine the effect of HS on liver microstructure and function in rats. A heat simulation chamber with ambient temperature (Ta) 45 ± 0.5 °C and relative humidity (RH) 30 ± 5 per cent was used to expose animals to HS. Rats were categorised as moderately heat stressed (MHS, Tc = 40 °C) and severely heat stressed (SHS, Tc = 42 °C) group. We observed that with rise in core temperature (Tc) alanine aminotransferase(ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) levels were increased but glucose level was decreased in both plasma and liver tissue. Significantly elevated levels of reactive oxygen species (ROS) and nitric oxide (NO) were detected in liver of MHS and SHS animals. Additionally, glutathione disulfide and glutathione (GSSG and GSH) ratio was found to be increased with rise in Tc which suggested saturation in antioxidant capacity of tissue. Furthermore, levels of heat shock proteins (HSPs) and caspases were upregulated upon HS. Results of histological examination indicated extensive loss of cells in liver parenchyma leading to disorganisation of lobular structure. Thus, biochemical and histological studies in experimental animals demonstrates that HS may severely altered structural and biochemical functions of liver.

Hsp30 is a plasma membrane localized heat shock protein in Saccharomyces cerevisiae whose expression is induced by numerous environmental stressors. Elucidation of its mechanism of action has remained elusive primarily because hsp30Δ cells do not show a strong phenotype. To identify cellular functions associated with Hsp30, we thus compared the transcriptome of BY4741hsp30Δ with that of its wild type counterpart. Our studies indicate down-regulation of the target of rapamycin complex 1 (TORC1)-dependent gene-expression programme in hsp30Δ cells. We further show that TORC1-signalling through its effectors (Sch9 and Tap42) was down-regulated in the deletion strain. Specifically, (a) phosphorylation levels of Sch9 were lower and nuclear exclusion of Rim15 (Sch9-downstream function) was overridden in hsp30Δ cells, (b) membrane association of Tor1 and Tap42 was lower in hsp30Δ cells, and (c) Tap42-downstream functions were abrogated in the deletion strain. Furthermore, transcription factors Rtg1, Rtg3, Gat1, and Gln3 were localized in the nucleus of the hsp30Δ as observed upon inactivation of TORC1. Studies aimed at determining how TORC1-signalling is down-regulated in hsp30Δ cells indicated that total reducing sugar levels were lower and ADP:ATP ratio was higher in hsp30Δ cells -conditions known to activate the Snf1 kinase and consequently to the inactivation of TORC1. We thus determined if TORC1-signalling could be restored in hsp30Δ cells upon the deletion of SNF1. Sch9 phosphorylation levels (TORC1-signalling) was restored to wild type levels in hsp30Δsnf1Δ cells. TORC1-signalling is thus down-regulated in hsp30Δ cells by SNF1-dependent mechanisms. A probable role for Hsp30 is discussed.

Increased environmental temperature exerts a visible impact on an individual's physiology. At the onset of heat stress, there is an increase in core body temperature which triggers peripheral vasodilation and sweating in an effort to dissipate the elevated body heat. The increase in peripheral circulation however reduces blood flow to the internal organs which are thus adversely affected. In particular, the gastrointestinal (GI) tract gets adversely affected during hyperthermia resulting in loosening of the tight junctions (TJs) that finally leads to higher intestinal permeability. At the cellular level, elevated levels of heat shock proteins (HSPs) induced in response to heat stress mediated cytoprotection by maintaining proper protein folding, releasing survival signals and preserving cytoskeleton integrity. Recent studies have indicated that HSPs play a crucial role in maintaining the localization of TJ proteins. Dietary supplements have also shown to have a positive effect on the maintenance of intestinal TJs. Therefore, it becomes imperative to understand the cellular, molecular and physiological alterations in response to heat stress in GI tract. In the present report, the effect of thermal stress on GI tract has been summarized. Specific role of HSPs along with mitogen activated protein (MAP) kinase signaling pathway in response to hyperthermia has also been discussed.

There are significant amount of differences between an addicted and non-addicted person on their social and familial behavior. In this paper we tried to find out the characteristics of a person related to his social and familial life and also health issues that can prove his vulnerability to drug addiction. The research was held on the context of the people of Dhaka, Bangladesh and on an age group of 15 to 40 years. We have collected and analyzed data associated with addicted and non-addicted people from different areas of Dhaka. For addicted person’s data we reached some rehabilitation center of Dhaka and for non-addicted person’s data we communicated different aged group people of different colleges and universities. A machine learning approach then helped us to find out some features that differentiate between these two groups of people. This will help people to understand if a person is going to be addicted or not based on their health issues and social and familial behavior. Our questionnaire was constructed on the basis of Addiction Severity Index with the help of psychologists and specialists on drug addiction.

Electrostatic interactions provide a convenient way to modulate interactions between nanoparticles, colloids, and biomolecules because they can be adjusted by the solution pH or salt concentration. While the presence of salt provides an easy method to control the net interparticle interaction, the nonlinearities arising from electrostatic screening make it difficult to quantify the strength of the interaction. In particular, when charged particles assemble into clusters or aggregates, nonlinear effects render the interactions strongly non-pairwise. Here we report Brownian dynamics simulations to investigate the effect that the non-pairwise nature of electrostatic interactions has on nanoparticle assembly. We compare these simulations to a system in which the electrostatics are modeled by a strictly pairwise Yukawa potential. We find that both systems show a narrow range in parameter space where the particles form well-ordered crystals. Bordering this range are regions where the net interactions are too weak to stabilize aggregated structures, or strong enough that the system becomes kinetically trapped in a gel. The non-pairwise potential differs from the pairwise system in the appearance of an amorphous phase for strongly charged particles. This phase appears because the many-body electrostatic interactions limit the maximum density achievable in an assembly., 13 pages, 5 figures

A general method for calculating the Rayleigh scattering by a particle of arbitrary shape is introduced. Although analytical solutions for Rayleigh scattering exist for spheres and ellipsoids, analytical solutions for more complicated shapes don’t exist. We find that in general the Rayleigh differential cross section goes as k 4 V 2 | α ( m ) | 2 where k = 2 π / λ and λ is the wavelength, V is the volume of the particle and α ( m ) the average volume polarizability which is dependent on the shape and the complex index of refraction, m. We use existing computational techniques, the discrete dipole approximation (DDA) and the T-matrix method, to calculate the differential scattering cross section divided by k 4 and plot it vs V 2 to determine | α ( m ) | 2 . Furthermore, we show that this leads to a general description of the internal coupling parameter ρ arbitrary ′ = 2 π k V A | α ( m ) | where A is the average projected area of the particle in the direction of incident light. It is shown that this general method makes significant changes in the analysis of scattering by particles of any size and shape.

Malignant Perivascular Epitheloid Cell Tumour (PEComa) of the lung is very rare, with only six cases reported in literature. This case presented with a large mass originating from right upper lobe of the lung with dilemma in its histopathological diagnosis and management. Postoperative histopathology after a right upper and middle lobectomy describes a tumour with an alveolar/nested pattern of growth and epitheloid morphology with expression of TFE-3 and diagnosed as PEComa. After 6 months the patient had a local recurrence inside the thorax & chest wall.This case qualifies it as a rare type of malignant PEComa with younger age of presentation, aggressive clinical behaviour & malignant histological features along with TFE3 positivity on immunohistochemistry. This case is probably the first of its kind with the largest reported size involving two lobes of the lung.

Q-space analysis is applied to extensive simulations of the single-scattering properties of ice crystals with various habits/shapes over a range of sizes. The analysis uncovers features common to all the shapes: a forward scattering regime with intensity quantitatively related to the Rayleigh scattering by the particle and the internal coupling parameter, followed by a Guinier regime dependent upon the particle size, a complex power law regime with incipient two dimensional diffraction effects, and, in some cases, an enhanced backscattering regime. The effects of significant absorption on the scattering profile are also studied. The overall features found for the ice crystals are similar to features in scattering from same sized spheres.

We report light scattering phase function measurements for irregularly shaped Al2O3 abrasive powders of various grit sizes. Q-space analysis is applied to the angular scattering to reveal a forward scattering regime, Guinier regime, power law regime with quantifiable exponents, and an enhanced backscattering regime. The exponents of the power laws for Al2O3 abrasives decrease with increasing internal coupling parameter ρ ′ , which is in agreement with previous observations for other irregular particles. Unlike other dust particles previously studied showing single power laws under Q-space analysis, the largest three abrasives, for which ρ ′ ≳ 100 , showed a kink in the power law, which is possibly due to the higher degree of symmetry for the abrasives than for all the particles studied previously. Direct comparison of the 1200, 1000, and 800 grit abrasive scattering to scattering by corresponding spheres shows that the scatterings approximately coincide at the spherical particle qR ≃ ρ ′ crossover point. Furthermore, the scattering at the maximum qR = 2 kR by the irregularly shaped abrasives is close to the geometric centers of the glories of the spheres.

Q-space analysis is applied to the scattered intensity from Gaussian Random Spheres (GRSs). Q-space analysis involves plotting the scattered intensity vs. the magnitude of the scattering wave vector q = 2 k sin θ 2 where k = 2 π / λ with λ the wavelength and θ is the scattering angle, on a log–log plot. The light scattering properties of GRSs were calculated using a discrete dipole approximation algorithm. The GRSs had σ=0.2 and ν=3, where σ is the relative standard deviation in the radial direction, and ν describes fluctuations in the angular direction. Calculations were systematically performed with size parameters ranging from 10 to 30, and with a relative index of refraction, m, ranging from 1.01 to 1.5. The results show quantifiable, power law descriptions of the scattered intensity and a Rayleigh functionality of the forward scattered intensity that depend upon the phase shift parameter ρ = 2 k R eq | m − 1 | where R eq is an equivalent radius. Similar functionalities have been observed in both spheres and other irregularly shaped particles. These results continue the implication that there is a comprehensive description of light scattering for all particles that can be uncovered with the application of Q-space.

We report Q-space analysis of light scattering phase function data for irregularly shaped dust particles and of theoretical model output to describe them. This analysis involves plotting the scattered intensity versus the magnitude of the scattering wave vector q = (4π/λ)sin(θ/2), where λ is the optical wavelength and θ is the scattering angle, on a double-logarithmic plot. In q-space all the particle shapes studied display a scattering pattern which includes a q-independent forward scattering regime; a crossover, Guinier regime when q is near the inverse size; a power law regime; and an enhanced backscattering regime. Power law exponents show a quasi-universal functionality with the internal coupling parameter ρ′. The absolute value of the exponents start from 4 when ρ′

We consider light scattering by uniform spheres of arbitrary size R and refractive index m . A new internal coupling parameter ρ ' = 2 k R | ( m 2 − 1 ) / ( m 2 + 2 ) | where k = 2 π / λ and λ is the wavelength is proposed that has a superior ability to determine the asymptotic regimes of small size, weakly refractive and large size, refractive than the parameter ρ = 2 k R ( m − 1 ) . It also has superior ability as a parameter to organize patterns in light scattering from spheres.

Angiosarcoma, despite being the most common primary malignant tumour of the heart and pericardium, is itself an extremely rare tumour with a 0.001 to 0.003 % prevalence in an autopsy series. Angiosarcoma is the most common form of malignant cardiac tumour, having a tendency to occur in the third to fifth decade of life, with a distinct male preponderance. The tumour is often silent and symptomless for a long period of time, presenting late with locoregional metastasis which hampers the operability and prognosis. Metastasis is mainly to the mediastinal lymph nodes, lungs and vertebra. We present the case of a 58-year-old normotensive diabetic male who presented with dyspnea on exertion and recurrent pericardial effusion with an impending cardiac tamponade. It was identified as a large pericardial mass on CT thorax, and partial pericardiectomy was done. Histopathology identified it as a poorly differentiated carcinoma. It was only by immunohistochemistry that the diagnosis of pericardial angiosarcoma was confirmed.

We report measurements of the light scattering matrix elements of Arizona Road Dust, which has irregular shapes. Our experimental apparatus used photodiode arrays to detect scattered light simultaneously at many angles including small angles that are necessary for accurate characterization of large particles. The setup was calibrated with single slit diffraction and water droplet scattering. Guinier analysis yielded the dust particle size. Q-space analysis of the dust scattering yielded a comprehensive description of scattering in terms of power laws with quantifiable exponents.

Ibogaine may have antiaddiction potential against alcohol, psychostimulant and opiate abuse, but its mechanism of action is unclear. Ibogaine, however, has been demonstrated in numerous studies to have effects in multiple central nervous system (CNS) neurotransmitters systems. We are using in vitro and in vivo systems to study the effects of cocaine and whether these effects can be blocked by ibogaine. For the in vivo studies, we first determined the acute and subacute effects of ibogaine (1-5.0 mg/kg) in mice using the plus-maze test. Acutely increasing doses of ibogaine produced a reduced aversion to the open arms. The subacute administration provoked a variable response which was characterized by fluctuations in aversive and antiaversive behavior of the animals to the open arms of the plus-maze during the 14-day treatment period. A separate group of mice received 1.0 mg/kg cocaine for 14 days, and upon abrupt cessation from cocaine treatment, ibogaine 2.5 mg/kg was administered to a subgroup of these mice. Ibogaine reversed the withdrawal aversions produced by the abrupt cessation from cocaine administration. For the in vitro studies, the expression and activity of protein kinase C (PKC) isoforms and Ca2+ levels were examined following the incubation of PC 12 cells with cocaine. This is because PKC plays a key role in a number of cellular and neuronal functions. We report that cocaine disrupts signal transduction in PC 12 cells by altering the expression and activity of PKC isoforms and Ca2+ levels. The data obtained suggest (1) that the PC 12 cells may be useful in studying the neurobiology of abused drugs, like cocaine in vitro, (2) that if anxiety is a factor in drug dependency, then the antiaddictive property of ibogaine in vivo may be associated with modifying the CNS neurotransmission that may be involved in anxiety. It remains to be determined whether the signaling involving PKC is important in the antiaddictive properties of ibogaine.

We define the partial scattering cross section and partial efficiencies to demonstrate that the total scattering is the sum of two roughly equal parts: approximately half from the forward scattering lobe due to 2D diffraction by the projected sphere and half from the 2D to 3D diffraction crossover. The first part is at angles such that θ≲λ/D, a result previously known, which can be quite small for large particles. The second part is in a new regime we call the "hump," visible in q-space, which to a good approximation contains the other half of the scattered light. The hump disappears when the imaginary part of the refractive index is significant.

COVID19 pandemic has badly affected thoracic surgical services. In this difficult time Thoracic surgeons all over the world are boldly managing thoracic malignancies and life-threatening problems of benign thoracic diseases. Infection control, safety of patients & healthcare personnel remains the cornerstone. In this article we present our experience of Thoracic surgery during this pandemic. Our results & experience are similar to the guidelines & survey reports published by thoracic surgeons till date.

We investigate, through simulation, a system of aggregating particles in the free molecular regime that undergoes a crossover from ballistic to diffusive motion. As the aggregates grow, the aggregate mean free path becomes smaller and the motion between collisions becomes more diffusive. From growth kinetics, we find that when the ratio of the aggregate mean path to the mean aggregate nearest neighbor separation reaches of the order of unity, a crossover to diffusive motion occurs. This ratio, called the nearest neighbor Knudsen number, becomes an important parameter in understanding aerosol aggregation in the free molecular regime.Copyright 2014 American Association for Aerosol Research

This paper applies the Q-space analysis method to the scattering phase function of small irregular particles. Q-space analysis involves plotting the scattered intensity versus the magnitude of the scattering wave vector q =(4 π / λ ) sin( θ /2) on a double log plot. Four types of irregularly shaped particles were studied: strongly damaged spheres, rough surface spheres, pocked spheres, and agglomerated debris particles. The angular scattering phase function was calculated using the discrete dipole approximation (DDA). The Q-space analysis uncovered power law descriptions of the scattering as it has previously for aggregates, spheres and dusts, although in some situations the description is marginal. It also showed that the forward scattering lobe has Rayleigh functionalities on size and refractive index. These results imply that Q-space analysis can yield a comprehensive description of scattering in terms of power laws with quantifiable exponents for a wide variety of particle shapes. However, a theoretical explanation of the power laws and the values of the numerical exponents is lacking.

The Ubiquitin Proteasomal System is one of the major proteolytic pathways in eukaryotic cells and is required for the regulation and execution of numerous cellular processes. Specifically, it is required for the progression of the cell cycle, in antigen processing, in mounting an inflammatory response as well as for the degradation of damaged and miss-folded proteins. Unregulated Proteasomal activity leads to several human pathological conditions including cancer. The proteasome is thus a target for the development of drugs for the treatment of several human disease conditions. Here we summarize proteasomal inhibitors isolated from bacteria and fungi.

Silica (SiO2) aerosol gels were formed via Brownian aggregation of silica nanoparticles in a closed reaction chamber. A sudden and quick detonation reaction of pyrophoric silane (SiH4) with either oxygen or nitrous oxide created silica nanoparticles with diameters ranging from ∼22 to 90 nm in the presence of an inert background gas with a volume fraction of ca. 10−4, conditions necessary for gelation. The background gas was necessary for quick thermal quenching of freshly formed silica molecules and molten nanoparticles and some control of the particle size could be achieved by variation of the gas. The silica aerosol gels were found to have very low densities in the range 4–15 mg/cm3 and high specific surface areas of 300–500 m2/g. Wide angle X-ray diffraction showed that the nanoparticles were amorphous silica. Neutron scattering showed that they were arranged in networks with a fractal dimension of 1.75 between 10 and 1000 nm length scales. Copyright 2012 American Association for Aerosol Research

Ubiquitin conjugating enzyme 1 (Ubc1) is a member of the E2 family of enzymes that conjugates ubiquitin to damaged proteins destined for degradation by the ubiquitin proteasomal system. It is necessary for stress tolerance and is essential for cell survival in Saccharomyces cerevisiae. Ubc1 has five serine residues that are potential substrates for phosphorylation by kinases. However, no data are available to indicate that Ubc1 function or stress tolerance in S. cerevisiae is regulated by serine phosphorylation of Ubc1. We demonstrate that Ubc1 is phosphorylated in serine residue(s). Furthermore, expression of Ubc1 mutants that are ‘constitutively phosphorylated’ or ‘dephosphorylated’ in mitogen-activated protein (MAP) kinase serine residues (S97 and S115) affected tolerance to thermal and reductive stress in S. cerevisiae. Specifically, expression of Ubc1S97A and S115D increased thermo-tolerance in both BY4741 and TetO7-UBC1ura3Δ cells. Serine phosphorylation of Ubc1 was decreased in BY4741 cells following exposure at 40 °C. Tolerance to reductive stress in the same strains correlated with the expression of Ubc1S97A. Ubc1 phosphorylation did not show significant alteration under similar conditions. Both hog1Δ and slt2Δ cells expressing Ubc1S115D and Ubc1S115A were rendered tolerant to thermal and reductive stress respectively. Ubc1 phosphorylation was higher in BY4741 cells compared to hog1Δ cells at 30 °C and was significantly reduced in BY4741 cells upon exposure at 40 °C. Taken together, the cell survival assays and Ubc1 phosphorylation status in strains and under conditions as described above suggest that tolerance to thermal and reductive stress in S. cerevisiae may be regulated by MAP kinase-mediated phosphorylation of Ubc1S97 and S115. Copyright © 2011 John Wiley & Sons, Ltd.

DNA repair functions are essential for the maintenance of genetic integrity and are regulated in response to both environmental and chemical stressors in mammalian and yeast cells in culture. The inhibitory effect of limited O2 availability on DNA repair functions in general and on homologous recombination (HR) in particular, correlates with increased chromosomal abnormalities in hypoxic cancer cells. Given the above, we have investigated the effects of CoCl2,--a hypoxia mimetic agent on HR and genetic aberrations in Saccharomyces cerevisiae. Our studies demonstrate that both acute and chronic exposure to CoCl2 activated HR and increased genetic aberrations in S. cerevisiae D7 cells. At early time points following addition of CoCl2 to the growth media, cells were briefly arrested in the G1-S boundary concomitant with a transient increase in Rad52-GFP foci formation and induction of low levels of DNA damage. The mode of action of CoCl2 is thus similar to that of DNA synthesis inhibitors, the later are known to induce HR and cause G1-S arrest. We propose that the activation of HR in the presence of the hypoxia mimetic agent may be attributed to the replication stress and/or DNA damage induced by the stressor.

The exotic bialgebras that arise from a 9 × 9 unitary braid matrix are constructed. The dual bialgebra of one of these exotic bialgebras is presented.

This work presents a new explanation for the extinction paradox and shows that the canonical explanations are incorrect. This paradox refers to the large size limit of a particle's extinction cross section. It is called a paradox because the geometrical optics approximation, which should be valid in this limit, predicts a cross section that is half of the true value. The new explanation is achieved by formulating the scattered wave in terms of an integral over the particle's surface where the seemingly unrelated Ewald–Oseen theorem appears in the formulation. By expressing the cross section in terms of this surface integral, the Ewald–Oseen theorem is analytically connected to the cross section. Several illustrations are used to reveal the significance of this connection: The paradox is seen to be a consequence of the requirement that the incident wave be canceled within the particle by secondary radiation from its own internal field. Following this, the canonical explanations are examined to reveal serious problems. In the process, the same asymptotic extinction behavior is shown to occur for small highly refractive dielectric particles, and thus is not just a large particle size or small wavelength effect as is often stated. The traditional explanations cannot account for this behavior while the new one actually predicts it. All in all, this work constitutes a fundamental reworking of 60 years of accepted understanding for the cause of the asymptotic behavior of the extinction cross section.

Background: Relapsed platinum-resistant epithelial carcinoma of the ovary is a disease with a dismal prognosis. Bevacizumab and capecitabine have been used in carcinoma of ovary both as a single agent and with other chemotherapeutic medicine. A retrospective study has been performed to assess the efficacy of bevacizumab + capecitabine in relapsed platinum-resistant epithelial carcinoma of the ovary. Materials and Methods: Patients who suffered from relapsed platinum-resistant epithelial carcinoma of the ovary and received bevacizumab and capecitabine were included in the present study. The primary objective of this study was to assess response rate and progression-free survival (PFS). Treatment: Patients received capecitabine at a dose of 1250 mg/m2 twice daily from day 1 to day 14 in each cycle. Bevacizumab was given at a dose of 7.5 mg/kg on day 1 in each cycle. The cycle was repeated in every 3 weeks. Response evaluation was done using the Response Evaluation Criteria in Solid Tumor criteria and by Rustin criteria. Statistical Analysis: Statistical analysis was done using statistical software (SPSS 16, SPSS for Windows, SPSS Inc., Chicago, IL, USA). Results: We analyzed the data of 32 patients. The PFS was 10.51 (95% confidence interval [CI], 8.65–12.37) months. The overall survival (OS) was 20.53 (95% CI, 17.21–23.85) months. Four (12.5%) patients achieved complete response. Eighteen (56.25%) patients achieved partial response. The response rate was 68.75%. Four (12.5%) patients had progressive disease. Conclusion: Response rate, PFS, and OS of patients in this study are comparable to those of other published studies. Hence, bevacizumab + capecitabine can be used in relapsed platinum-resistant carcinoma of the ovary. The incidence and severity of bevacizumab-induced side effects are relatively lower in this study. Hence, bevacizumab can be given at a lower dose with comparable efficacy and tolerable side effects.

A review of the process by which irreversible aggregation of solid particles creates fractal aggregates which eventually fill the entire system volume to form a gel, the sol to gel transition, is presented. Both simulation and experiment present a coherent description of the kinetics and resulting morphologies of this process. Enhanced kinetics occurs when the system is cluster dense. Surprisingly, the enhanced kinetics is governed by the mean-field Smoluchowski equation deep into the aggregation process, displays universality with cluster volume fraction (or, equivalently the ratio of cluster separation to size, or time normalized by the gel time), and is described by one parameter, the aggregation kernel homogeneity. Aggregates show canonical cluster–cluster morphology until the point where the cluster volume fraction is unity; then hybrid superaggregates with fractal dimensions of ca. 1.8 over small length scales and 2.6 over large length scales form.

Benign coloesophageal anastomotic stricture in postoperative colon bypass patients suffering from the corrosive stricture of the upper esophagus is a challenging problem. Failure of repeated endoscopic balloon dilatation makes way for revisional operative techniques like free jejunal grafts or interposition skin tube based on radial vessels. The situation arising from the morbidity of such reconstructive procedures, at times, becomes more complex than the stricture itself [1]. This clinical scenario has compelled us to innovate with a much simpler technique using buccal mucosal graft (BMG) to manage these strictures. Currently, the utility of BMG is mostly limited to urethral reconstruction. Overtime, it has become an ideal urethral substitute. Here, we present a case series of five patients who have been subjected to coloesophagoplasty with BMG and have demonstrated excellent results. With a median follow-up of 13 months, all patients have fully recovered and are taking solid and liquid foods satisfactorily. Thus, the option of coloesophagoplasty with BMG should always be kept in consideration while planning a revision surgery for a small-segment benign coloesophageal anastomotic stricture in the corrosive injury of the esophagus, considering the ease and excellent outcome.

Saccharomyces cerevisiae Hsp30 is a plasma membrane heat shock protein which is induced by various environmental stress conditions. However functional role of Hsp30 during diverse environmental stressors is not presently known. To gain insight into its function during thermal stress, we have constructed and characterized a hsp30 strain during heat stress. BY4741Deltahsp30 cells were found to be more sensitive compared to BY4741 cells when exposed to a lethal heat stress at 50 degrees Celsius. When budding yeast is exposed to either heat shock or weak organic acid, it inhibits Pma1p activity. In this study we measured the levels of Pma1p in mutant and Wt cells both during optimal temperature and heat shock temperature. We observed that BY4741Deltahsp30 cells showed constitutive reduction of Pma1p. To gain further insights into the role of Hsp30 during heat stress, we compared total protein profile by 2D gel electrophoresis followed by identification of differentially expressed spots by LC-MS. We observed that contrary to that expected from thermal stress induced changes in gene expression, the Deltahsp30mutant maintained elevated levels of Pdc1p, Trx1p and Nbp35p and reduced levels of Atp2p and Sod1p during heat shock. In conclusion, Hsp30 is necessary during lethal heat stress, for the maintenance of Pma1p and a set of thermal stress response functions.

We report the results of a study of the kinetics of a dense aggregating aerosol system that show that the predictions of the Diffusion Limited Cluster Aggregation (DLCA) model no longer hold when the system is dense. We studied a soot aerosol using the small angle light scattering technique created by exploding a mixture of a hydrocarbon gas and oxygen in a closed chamber. The soot particles started as individual monomers, ca. 38 nm radius, grew to bigger fractal clusters with time and finally stopped evolving after spanning a network across the whole system volume. This spanning is aerosol gelation. The study of the kinetics of the aggregating system showed that as the system evolved from a cluster dilute to cluster dense system, the aggregation kernel homogeneity λ evolved from the dilute limit, DLCA value of zero to a value 0.42 +/− 0.05 at the gel point. This evolution is consistent with previous simulation and theory. The experimental value at the gel point is nearly equal to the value of 0.5 predict...

This work concerns a common problem in electromagnetic scattering; calculation of the total scattering, extinction, and absorption cross sections for an arbitrary particle. Typical expressions for the cross sections are obtained in terms of the vector spherical wave function expansions for the incident and scattered waves. The unique aspect of this work is that the derivation is carried out specifically without use of the far-field zone approximation. The resulting expressions, valid at any distance, exactly match those obtained from the far-field approximation. This demonstrates that the cross sections are independent of the distance from the particle at which they are calculated as one would expect from energy conservation. Numerical simulations of the near and far-field zone energy flows due to a spherical particle are presented to illustrate several implications of this result.

Ancient sediments reflect the compositions of old eroded continental crustal material and preserve geochemical signatures of paleo-tectonic and volcanic events. Geochemical study of such sediments provides insight into tectonic events that shaped the face of the Earth. Nd isotopes are best suited for such studies because rare earth elements (REE), specifically Sm and Nd are not fractionated during post-depositional processes such as erosion, transportation and diagenesis of organic-poor sediments and hence reflect the source composition of these sediments. Sedimentation in the Proterozoic Vindhyan Basin of central India with a ∼4 km thick succession of unmetamorphosed and mostly undeformed sediments lasted over 1000 Ma from ∼1630 Ma up to the Precambrian–Cambrian boundary. These sediments provide an ideal opportunity to study the evolution of ancient continental crust as well as the tectonic evolution of Peninsular India. The occurrence of porcellanites in the lower part of the basin indicates active volcanism during deposition of the Vindhyan sediments. These tuffs show large ion lithophile element (LILE) enrichment as well as depletions in Nb and Ta in primitive mantle-normalized plots, characteristic of an arc volcanic source. In combined trace element ratio plots, these volcanic rocks indicate mixing between mantle-derived melts and the continental crust and overlap with the composition of global arcs. Their initial ɛNd at 1630 Ma, ranging from −5.7 to −0.9, is similar to those observed in ‘Andean-type’ continental margin arcs. Trace element concentration patterns as well as Nd isotopic compositions of the clastic and non-clastic sediments of the Vindhyan Basin, from one of the type-localities of the Vindhyan stratigraphy in the Son valley, are vastly different from those of the Bundelkhand granite, which is the basement for these sediments, indicating that these granitic rocks were not a major source of sediments for the Vindhyan Basin. Our Nd isotopic study clearly indicates that sedimentation in the Vindhyan Basin, which lasted over ∼1 Ga, was not continuous. The boundaries between the Semri and Kaimur Groups as well as the Rewa and Bhander Groups are characterized by abrupt changes in the Nd isotopic compositions indicating changes in provenance, with sediments in the Kaimur and Bhander Groups being derived from more juvenile sources compared to the Semri and Rewa Groups, respectively. This inference is also supported by changes in TDM and fSm/Nd for the sediments across these boundaries. The strikingly different trace element patterns of the Rewa Group sediments compared to the underlying Kaimur sediments indicates that sediment sources also changed across the Kaimur–Rewa boundary. Multiple changes in provenance in the Vindhyan sediments indicate that this basin was tectonically active during the entire span of sedimentation. While there is some uncertainty in determining the exact sources of sediments for the Vindhyan Basin, we argue on the basis of our geochemical, in particular Nd-isotopic ratios data, and available paleocurrent data that majority of the sediments were derived from a now-extinct Andean-type arc source in the south that resulted from a southerly dipping subduction prior to the collision of the Bhandara and Bundelkhand cratons. According to this reconstruction, the Vindhyan Basin was initiated as a foreland Basin after the collision of these two cratons.

We demonstrate that an aerosol can gel. This gelation is then used for a one-step method to produce an ultralow density porous carbon material. This material is named an aerosol gel because it is made via gelation of particles in the aerosol phase. The carbon aerosol gels have high specific surface area (200–350 m 2 /g), an extremely low density (2.5–5.0 mg/cc) and a high electrical conductivity, properties similar to conventional aerogels. The primary particles of the carbon aerosol gels are highly crystalline with a narrow (002) graphitic X-ray diffraction peak. Key aspects to form a gel from an aerosol are large volume fraction, ca. 10 −4 or greater, and small primary particle size, 50 nm or smaller, so that the gel time is fast compared to other characteristic times.

The exotic bialgebra S03, defined by a solution of the Yang-Baxter equation, which is not a deformation of the trivial, is considered. Its FRT dual algebra $s03_F$ is studied. The Baxterisation of the dual algebra is given in two different parametrisations. The finite-dimensional representations of $s03_F$ are considered. Diagonalisations of the braid matrices are used to yield remarkable insights concerning representations of the L-algebra and to formulate the fusion of finite-dimensional representations. Possible applications are considered, in particular, an exotic eight-vertex model and an integrable spin-chain model., Comment: 24 pages, Latex; V2: revised subsection 4.1, added 9 references, to appear in Annales Henri Poincare in the volume dedicated to D. Arnaudon

A nonlinear realisation of the nonstandard (super-Jordanian) deformed ${\cal U}_{\sf h}(sl(N|1))$ algebra is given for arbitrary $N$.

The surface traces and bioturbate textures genereated by the bubbler crabsScopimera sp.,Dotilla blanfordi, Ilyoplax pusilla, etc., occurring in the tropical supra- to shallow-subtidal environments of the east coast of India have been studied. During foraging these organisms make various patterns on the substrate by their feeding pellets. These patterns are primarily dependant on grain-size characteristics, moisture conditions, and emergence level of the substrate. The crabs also produce typical ichnofabrics caused by back-filling of the burrows which do not exceed 10 cm in length. The internal fabric of the burrow-fills shows both concave-upward and concave-downward laminae resulting from upward or downward movement of the organism within the sediment. In sections perpendicular to burrow orientation the process of back-filling generates concentric laminae. Such a fabric occurs not only in coastal intertidal sediments, but also in sediments of estuarine point bars located 50 kilometres inland where these tiny crabs also occur. Such subsurface bioturbation features may represent a better tool for the identification of tidal environment than surface traces since the latter have a low preservation potential because of the erosional effects of wave and current action. The bioturbate texture, however, occurs over a wide range of the intertidal zone and, hence, in fossil record this bioturbate texture can be useful to identify tidal environments. These crabs can withstand a definite range of salinity and, therefore, this texture can also provide information about salinity conditions of palaeo-tidal environments.

We show that soot formed in laminar diffusion flames of heavily sooting fuels evolves through four distinct growth stages which give rise to four distinct aggregate fractal morphologies. Each successive stage grows upon the previous stage; hence aggregates of one morphology, parameterized by a fractal dimension, form larger superaggregates or gels of a different morphology with a different fractal dimension. These results were inferred from large and small angle static light scattering from the flames, microphotography of the flames, and analysis of soot sampled from the flames. These results and the analysis were substantiated by comparison to computer simulations. The growth stages occur approximately over four successive orders of magnitude in aggregate size. Each growth stage is a fundamental physical process: Stages 1 and 3 are diffusion limited cluster aggregation in three and two dimensions, respectively; Stages 2 and 4 are percolation in three and two dimension, respectively.