Inertial active harmonic particle with memory induced spreading by viscoelastic suspension.

We investigate the self-propulsion of an inertial active particle confined in a two-dimensional harmonic trap. The particle is suspended in a non-Newtonian or viscoelastic suspension with a friction kernel that decays exponentially with a time constant characterizing the memory timescale or transient elasticity of the medium. By solving the associated non-Markovian dynamics, we identify two regimes in parameter space distinguishing the oscillatory and non-oscillatory behavior of the particle motion. By simulating the particle trajectories and exactly calculating the steady-state probability distribution functions and mean square displacement; interestingly, we observe that with an increase in the memory time scale, the effective temperature of the environment increases. As a consequence, the particle becomes energetic and spread away from the center, covering larger space inside the confinement. On the other hand, with an increase in the duration of the activity, the particle becomes trapped by the harmonic confinement.

Inertial active ratchet: Simulation versus theory.

We present the inertial active dynamics of an Ornstein-Uhlenbeck particle in a piecewise sawtooth ratchet potential. Using the Langevin simulation and matrix continued fraction method (MCFM), the particle transport, steady-state diffusion, and coherence in transport are investigated in different parameter regimes of the model. Spatial asymmetry is found to be a key criterion for the possibility of directed transport in the ratchet. The MCFM results for net particle current of overdamped dynamics of the particle agree well with the simulation results. The simulated particle trajectories for the inertial dynamics and the corresponding position and velocity distribution functions reveal that the system passes through an activity-induced transition in the transport from the running phase to the locked phase of the dynamics. This is further corroborated by the mean square displacement (MSD) calculations, where the MSD gets suppressed with increase in the persistent duration of activity or self-propulsion in the medium and finally approaches zero for a very large value of self propulsion time. The nonmonotonic behavior of the particle current and Péclet number with self-propulsion time confirms that the particle transport and its coherence can be enhanced or reduced by fine tuning the persistent duration of activity. Moreover, for intermediate ranges of self-propulsion time as well as mass of the particle, even though the particle current shows a pronounced unusual maximum with mass, there is no enhancement in the Péclet number, instead the Péclet number decreases with mass, confirming the degradation of coherence in transport.

Inertial active Ornstein-Uhlenbeck particle in the presence of a magnetic field.

We consider an inertial active Ornstein-Uhlenbeck particle in an athermal bath. The particle is charged, constrained to move in a two-dimensional harmonic trap, and a magnetic field is applied perpendicular to the plane of motion. The steady-state correlations and the mean-square displacement are studied when the particle is confined as well as when it is set free from the trap. With the help of both numerical simulation and analytical calculations, we observe that inertia plays a crucial role in the dynamics in the presence of a magnetic field. In a highly viscous medium where the inertial effects are negligible, the magnetic field has no influence on the correlated behavior of position as well as velocity. In the time asymptotic limit, the overall displacement of the confined harmonic particle gets enhanced by the presence of a magnetic field and saturates for a stronger magnetic field. On the other hand, when the particle is set free, the overall displacement gets suppressed and approaches zero when the strength of the field is very high. Interestingly, it is seen that in the time asymptotic limit, the confined harmonic particle behaves like a passive particle and becomes independent of the activity, especially in the presence of a very strong magnetic field. Similarly, for a free particle the mean-square displacement in the long time limit becomes independent of activity even for a longer persistence of noise cor- relation in the dynamics.

Orbital magnetism of an active particle in viscoelastic suspension.

We consider an active (self-propelling) particle in a viscoelastic fluid. The particle is charged and constrained to move in a two-dimensional harmonic trap. Its dynamics is coupled to a constant magnetic field applied perpendicular to its plane of motion via Lorentz force. Due to the finite activity, the generalized fluctuation-dissipation relation (GFDR) breaks down, driving the system away from equilibrium. While breaking GFDR, we have shown that the system can have finite classical orbital magnetism only when the dynamics of the system contains finite inertia. The orbital magnetic moment has been calculated exactly. Remarkably, we find that when the elastic dissipation timescale of the medium is larger (smaller) than the persistence timescale of the self-propelling particle, it is diamagnetic (paramagnetic). Therefore, for a given strength of the magnetic field, the system undergoes a transition from diamagnetic to paramagnetic state (and vice versa) simply by tuning the timescales of underlying physical processes, such as active fluctuations and viscoelastic dissipation. Interestingly, we also find that the magnetic moment, which vanishes at equilibrium, behaves nonmonotonically with respect to increasing persistence of self-propulsion, which drives the system out of equilibrium.

COVID-19 lockdown: Effects on selected volatile organic compound (VOC) emissions over the major Indian metro cities.

Due to the COVID-19 pandemic, many countries across the world, including India, have imposed nationwide lockdowns to contain the spread of the virus. Many studies reported that the air quality had improved much due to the lockdown. This study examines the variation of Volatile Organic Compounds (VOCs) over the Indian metropolitan cities during the lockdown period by using ground-based and satellite observations. Ground-based BTEX (Benzene, Toluene, Ethylbenzene, and Xylenes) measurements from various metropolitan cities have shown a drastic drop of about 82% in the first phase of lockdown when compared with the pre-lockdown period. Whereas the spatial distribution of formaldehyde (HCHO), obtained from the TROPOspheric Monitoring Instrument (TROPOMI) onboard Sentinal-5P satellite, did not show any significant variation due to COVID-19 lockdown, indicating the major source of HCHO is biogenic or pyrogenic. The BTEX ratios were evaluated for a better understanding of the source and photochemical age of the air samples. The ozone forming potential of BTEX in all locations was found reduced; however, the corresponding decrease in ozone concentrations was not observed. The increase in ozone concentrations during the same period indicates alternative sources contributing to ozone formation.

A mitochondrial neurogastrointestinal encephalomyopathy with intestinal pseudo-obstruction resulted from a novel splice site mutation.

Mitochondrial neurogastrointestinal encephalopathy (MNGIE) is an autosomal recessive disorder characterized by gastrointestinal dysmotility, cachexia, ptosis, peripheral neuropathy and leukoencephalopathy. The diagnosis is often not made until 5-10 years after the onset of symptoms. MNGIE is caused by mutations in thymidine phosphorylase gene TYMP. Here, we present a 19-year-old boy with MNGIE who had a chronic intestinal pseudo-obstruction, and we describe his family history. Genetic analysis revealed a novel homozygous c.765+1G>C intronic mutation which is expected to disrupt splicing of TYMP in the patient. Family screening revealed that the brother was also affected and the mother was a carrier. MNGIE should be considered and genetic testing instigated if individuals with cachexia have neuromuscular complaints or symptoms of chronic intestinal pseudo-obstruction.

Responses of the zooplankton community to peak and waning periods of El Niño 2015-2016 in Kavaratti reef ecosystem, northern Indian Ocean.

The study addressed the impact of the El Niño 2015-2016 on the ecosystem functioning and the subsequent effects on the distribution and community structure of zooplankton in the Kavaratti reef, a prominent coral atoll in the tropical Indian Ocean. The elevated ocean temperature (SST) associated with El Niño resulted in a mass bleaching event affecting > 60% of the live corals of the Kavaratti atoll. The concomitant changes observed in the nutrient concentration, coral health, and phytoplankton of the reef environment during the course of the El Niño led to discernible variations in the zooplankton community with markedly higher abundance and heterogeneity in distribution during the peak period of El Niño compared to its waning phase. A notable shift was also evident in the community structure of Copepoda, the dominant zooplankton taxon, with a predominance of calanoids and poecilostomatoids in the peak period and by harpacticoid copepods in the waning phase of the El Niño. The harpacticoid, Macrosetella gracilis, dominated in the waning phase because of their unique adaptability in the utilization of Trichodesmium erythraeum, both as nutritional and physical substrates in the nutrient-depleted environment of the reef ecosystem.

Eotaxin-1 is involved in parasite clearance during chronic filarial infection.

Eosinophil migration as key feature of helminth infection is increased during infection with filarial nematodes. In a mouse model of filariasis, we investigated the role of the eosinophil-attracting chemokine Eotaxin-1 on disease outcome. BALB/c and Eotaxin-1(-/-) mice were infected with the rodent filaria Litomosoides sigmodontis, and parasitic parameters, cellular migration to the site of infection, and cellular responsiveness were investigated. We found increased parasite survival but unaffected eosinophil migration to the site of infection in Eotaxin-1(-/-) mice. Expression of CD80 and CD86 was reduced on eosinophils from Eotaxin-1(-/-) mice after in vitro TLR2 stimulation and exposure to filarial antigen, respectively, suggesting a potential reduced activation state of eosinophils in Eotaxin-1 deficient mice. We further demonstrated that macrophages from Eotaxin-1(-/-) mice produce decreased amounts of IL-6 in vitro, a cytokine found to be associated with parasite containment, suggesting possible mechanisms by which Eotaxin-1 regulates activation of inflammatory cells and thus parasite survival.

Coverage of adolescent substance use prevention in state frameworks for health education: 10-year follow-up.

BACKGROUND: The use of alcohol, tobacco, and other drugs (ATOD) by adolescents is a national health issue. One way in which the United States approaches the prevention of substance use among adolescents is by teaching high school students about ATOD at school. The curriculum for health education courses is based upon each state's framework. The purpose of this study was to conduct a 10-year follow-up to a study that analyzed state frameworks for key mediators of adolescent substance use. METHODS: Researchers performed an extensive content analysis of all 50 states' curriculum frameworks for high school health education to identify if, and to what degree, key mediators of adolescent substance use were included in each state's curriculum framework. After training, inter-rater agreement was greater than 95%. RESULTS: Mediators identified most often in the 50-state curriculum frameworks for high school health education were beliefs about consequences, decision making, social skills, assistance skills, and goal setting. Twenty-two of 50-state curriculum frameworks for high school health education had dedicated sections for ATOD. CONCLUSION: There were modest improvements since 2001 in the inclusion of mediators of adolescent substance use within state curriculum frameworks. There still exists many opportunities to more effectively use curriculum frameworks to improve classroom health instruction.

Genetic diversity of rice tungro spherical virus in tungro-endemic provinces of the Philippines and Indonesia.

The two adjacent genes of coat protein 1 and 2 of rice tungro spherical virus (RTSV) were amplified from total RNA extracts of serologically indistinguishable field isolates from the Philippines and Indonesia, using reverse transcriptase polymerase chain reaction (RT-PCR). Digestion with HindIII and BstYI restriction endonucleases differentiated the amplified DNA products into eight distinct coat protein genotypes. These genotypes were then used as indicators of virus diversity in the field. Inter- and intra-site diversities were determined over three cropping seasons. At each of the sites surveyed, one or two main genotypes prevailed together with other related minor or mixed genotypes that did not replace the main genotype over the sampling time. The cluster of genotypes found at the Philippines sites was significantly different from the one at the Indonesia sites, suggesting geographic isolation for virus populations. Phylogenetic studies based on the nucleotide sequences of 38 selected isolates confirm the spatial distribution of RTSV virus populations but show that gene flow may occur between populations. Under the present conditions, rice varieties do not seem to exert selective pressure on the virus populations. Based on the selective constraints in the coat protein amino acid sequences and the virus genetic composition per site, a negative selection model followed by random-sampling events due to vector transmissions is proposed to explain the inter-site diversity observed.

International Congress of Chemotherapy--21st meeting. 4-7 July 1999, Birmingham, UK.

Held every two years, the International Congress of Chemotherapy (ICC) represents one of the most important scientific meetings focusing on antimicrobial and anticancer research as well as therapeutics. The chairman of the scientific committee of the congress, Richard Wise (Professor in Clinical Microbiology, Birmingham University, UK) described the meeting as a timely opportunity to review and discuss the challenges and advances in the diagnosis, treatment and prevention of infection. 3300 Delegates from 78 countries were in attendance.

World pharmaceuticals--Financial Times tenth annual conference. 22-23 April 1999, London, UK.

This two-day conference was organized by The Financial Times, in association with PriceWaterhouseCoopers LLP. The general theme of the event was the state of the healthcare industry, past, present and future. The main areas covered included addressing the challenges of the 1990s, anticipating the challenges of the next decade, the changing shape of global marketing, IT in healthcare, consolidation challenges, shareholder expectations, and new strategies and technologies for growth sustenance within the industry. Key speakers within the industry addressed these issues to an audience of approximately 200 healthcare business executives. The first day was chaired by Mr Robert Cawthorn (Chairman Emeritus, Rhone-Poulenc Rorer Inc) and the second by Professor Trevor Jones (Director General, Association of the British Pharmaceutical Industry).

INFOTECHpharma '99--the information revolution in the pharmaceutical industry. 28-29 January 1999, London, UK.

This meeting bought together 180 directors and heads of research spanning all disciplines of the pharmaceutical industry. With the backdrop of increasing globalization, the major theme of the conference was concerned with the necessary improvement of pharmaceutical development processes. The role of new and emerging technologies in the increasing number of new leads generated, and the necessary information and knowledge management that this entails was examined from the perspective of R and D process improvement. Identifying superior clinical candidates using predictive ADME parameters, thereby avoiding costly screening processes, was addressed, while at the post-launch stage of the process the use of IT and www technology and how these can be effectively integrated into the business process to enhance productivity was reviewed.

Sustaining growth and profitability--The Economist fifth annual pharmaceuticals conference. 12-13 November 1998, London, UK.

This two-day conference, organized by The Economist, focused on R and D productivity, strategic and innovative methodologies, M and A activities and knowledge management within the pharmaceutical industry. Key speakers within the industry addressed these issues to an audience of approximately 100 healthcare business executives. The first day was chaired by Barrie Haigh (Quintiles Translational Corp) and the second day by Tobias Rooney (Gemini Consulting).