6,513 research outputs found
An Explication of Pandemic Public Health Emergency, Coronavirus Disease 2019 (COVID-19): A Review
In December 2019 a series of acute atypical respiratory disease occurred in Wuhan, China. The first clusters of cases were identified in association with the South China Seafood Market. In subsequent investigations it was found to be a novel coronavirus. It is suggested to have zoonotic origin. On December 31st 2019, China notified the outbreak to the World Health Organization. During the New Year, the massive migration of Chinese fuelled the epidemic. Cases in other provinces of China and other countries (South Korea, Thailand and Japan in quick succession) were reported in people who were returning from Wuhan. On 11 February, on the basis of existing rules on taxonomy the virus was names as SARS-CoV-2. SARS-CoV-2 belongs to the family of coronaviruses. It is a positive-sense single-stranded RNA (+ssRNA) virus. It has a single linear RNA segment. On the same day WHO announced the new name for the disease i.e. Coronavirus disease 2019 (COVID-19). The WHO and the US Centers for Disease Control and Prevention (CDC) say it is primarily spread directly due to close contact between people through small droplets produced during coughing, sneezing or talking within a range of about 1-3 meters. It may even transmit through indirect contact via fomites. While there are concerns it may spread by feces, this risk is believed to be low. Soon, the number of cases started increasing exponentially and on March 12, 2020 WHO announced COVID-19 a pandemic. COVID-19 has been impacting a large number of people worldwide, being reported in approximately 200 countries and territories. It was identified that Angiotensin converting enzyme 2 (ACE2) act as a functional receptor for SARS-CoV-2. The pathophysiology of COVID-19 follows sex differences, age differences, race differences in as well as underlying disease conditions i.e. comorbidities aggravated the severity of this disease. The most common symptoms being reported are fever, dry cough or chest tightness, and dyspnoea. It is now widely recognized that respiratory symptoms of COVID-19 are extremely heterogeneous, ranging from minimal symptoms to significant hypoxia with ARDS. Diagnosis is done with the help of history, clinical signs and serological testing. Real-time reverse transcription polymerase chain reaction (rRT-PCR) is considered the standard method of testing. Several have been tested in clinical trials but none of them have been proven to be a definite therapy yet. The evolution of the current outbreak has seen extraordinary measures put in place to control transmission, including the ‘shut-down’ and ‘quarantine’. Researchers are trying to develop a vaccine against SARS-CoV-2 but at present, no vaccine is available. One should strictly follow all the preventive measures as directed by WHO and CDC and along with this, one should boost up its natural immunity to lessen the chances of getting infection
VARIATION IN ANTIOXIDANT POTENTIAL OF CURCUMA LONGA L. COLLECTED FROM DIFFERENT ECOLOGICAL NICHES OF WESTERN HIMALAYAN REGION
Objective: The present study aims to evaluate the nutritional content and antioxidant activities of twenty accessions of turmeric rhizome from various locations of Uttarakhand.Methods: The antioxidant activity was evaluated by different method viz; DPPH radical scavenging activity, ferric reducing antioxidant power assay (FRAP), Hydroxyl radical scavenging activity, Nitric Oxide (NO) scavenging activity, Superoxide anion radical scavenging activity and nutritional value viz; total phenolic content, total flavonoid content, total ortho-dihydroxy phenols, total ascorbic acid content and total antioxidant capacity.Results: Alcoholic extracts of different turmeric rhizomes showed wide variation in abilities to scavenge nitric oxide, hydroxyl, superoxide free radical, DPPH with IC50 values in the range of 39.03-76.14, 39.77-72.85, 43.77-77.13, 64.38-271.95 µg/ml and FRAP value 19.54-54.84 µmole. The total phenolic content, total flavonoid content, total ortho-dihydroxy phenols, total ascorbic acid content and total antioxidant capacity of different alcoholic extracts of rhizomes were found in the range of 11.19-51.49, 6.35-30.95, 0.93-8.12, 0.14-1.29 and 27.44-94.78 mg/g respectively.Conclusion: The alcoholic extract of different accessions of Curcuma longa L. has shown excellent biochemical and antioxidant potential and therefore refers as an important natural source of antioxidant.Â
Tolerância ao calor de caprinos e ovinos sem-lã em Sobral.
Resumo: Caprinos das raças Canindé, Anglo-Nubiana e Bhuj e avinos sem-la Morada Nova e Santa Inês foram comparados quanta às temperaturas retais e taxa respiratoria, antes e imediatamente apos o exercício e durante o período de uma hora de repouso apos o0 exercicio, para avaliaçao da tolerância ao calor ambiental. Resultados mostraram que a temperatura retal inicial nao foi diferente entre as cinco raças; apos exercicio, elevou de 1,25ºC até 1,95ºC nas diferentes raças; nao houve diferença da elevaçao da temperatura corporal entre espécies. Apos exercício, a recuperaçao foi rapida nos caprinos Bhuj e Canindé. A recuperaçao foi mais lenta na Anglo-Nubiana e nos avinos. A variaçao inicial no ritmo respiratorio apresentou-se elevada na Anglo-Nubiana em comparaçao com as outras raças de caprinos e avinos. Depois do exercicio, os avinos apresentaram menoI elevaçao no ritmo respiratorio do que os caprinos. Isto pode explicar o grau de recuperaçao mais rapida da temperatura corporal dos caprinos Bhuj e Canindé, os quais tiveram distintamente os mais elevados ritmos respiratorios após o exercicio. 0 ritmo respiratório da Anglo-Nubiana voltou ao normal dentro de 15 minutas apos o exercicio; somente o da Bhuj continuou elevado após os 15 minutos de descanso. Todas as espécies voltaram ao ritmo respiratório normal, após os trinta minutos de descanso. [Heat tolerance of goats and woolless sheep in Sobral Brazil]
Changes in concentration and size distribution of aerosols during fog over the south Indian Ocean
Measurements of the concentration and size distribution of aerosol particles in the size-ranges of 0.5-20 μm and 16-700 nm diameters were made during six fog episodes over the south Indian Ocean. Observations show that concentrations of particles of all sizes start decreasing 1-2 hours before the occurrence of fog. This decrease is more prominent for coarse particles of >1 μm diameter and continues until 10-20 minutes before the onset of fog when particle concentrations in all size ranges rapidly increase by one/two orders of magnitude in ~20 minutes. Thereafter, concentrations of particles of all sizes gradually decrease until the dissipation of fog. After the fog dissipation, concentrations of coarse mode particles rapidly increase and restore to their pre-fog levels but concentrations of the Aitken mode particles decrease slowly and reach their pre-fog levels only after 1-2 hours. The net effect of fog is to change the bimodal size distributions of aerosols with a coarse mode at 1.0 μm and an accumulation mode at 40-60 nm to a power law size distribution. It is proposed that the preferential growth and sedimentation of the coarse mode hygroscopic particles in the initial phase cause a large decrease in the aerosol surface area. As a result, the low vapour pressure gases which were initially being used for the growth of coarse mode particles, now accelerate the growth rates of the accumulation and Aitken mode particles
Airborne measurements of submicron aerosols across the coastline at Bhubaneswar during ICARB
Airborne measurements of the number concentration and size distribution of aerosols from 13 to 700 nm diameter have been made at four vertical levels across a coastline at Bhubaneswar (20°25'N, 85°83'E) during the Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB) programme conducted in March-April 2006. The measurements made during the constant-level flights at 0.5, 1, 2 and 3 km altitude levels extend ~100 km over land and ~150km over ocean. Aerosol number concentrations vary from 2200 to 4500 cm-3 at 0.5 km level but are almost constant at ~6000 cm-3 and ~800 cm-3 at 2 and 3 km levels, respectively. At 1km level, aerosol number concentration shows a peak of 18,070 cm-3 around the coastline. Most of the aerosol size distribution curves at 0.5 km and 1 km levels are monomodal with a maxima at 110 nm diameter which shifts to 70 nm diameter at 2 and 3 km levels. However, at the peak at 1 km level, number concentration has a bimodal distribution with an additional maximum appearing in nucleation mode. It is proposed that this maxima in nucleation mode at 1 km level may be due to the formation and transport of new particles from coastal regions
Charge and Spin Response of the Spin--Polarized Electron Gas
The charge and spin response of a spin--polarized electron gas is
investigated including terms beyond the random phase approximation. We evaluate
the charge response, the longitudinal and transverse spin response, and the
mixed spin--charge response self--consistently in terms of the susceptibility
functions of a non--interacting system. Exchange--correlation effects between
electrons of spin and are included following Kukkonen and
Overhauser, by using spin--polarization dependent generalized Hubbard local
field factors and . The general
condition for charge--density and spin--density--wave excitations of the system
is discussed.Comment: 4 pages, latex, no figure
Simultaneous observations of ESF irregularities over Indian region using radar and GPS
In this paper, we present simultaneous observations of temporal and spatial variability of total electron content (TEC) and GPS amplitude scintillations on L1 frequency (1.575 GHz) during the time of equatorial spread F (ESF) while the MST radar (53 MHz) located at Gadanki (13.5° N, 79.2° E, Dip latitude 6.3° N), a low latitude station, made simultaneous observations. In particular, the latitudinal and longitudinal extent of TEC and L-band scintillations was studied in the Indian region for different types of ESF structures observed using the MST radar during the low solar activity period of 2004 and 2005. Simultaneous radar and GPS observations during severe ESF events in the pre-midnight hour reveal that significant GPS L band scintillations, depletions in TEC, and the double derivative of the TEC index (DROTI), which is a measure of fluctuations in TEC, obtained at low latitudes coincide with the appearance of radar echoes at Gadanki. As expected, when the irregularities reach higher altitudes as seen in the radar map during pre-midnight periods, strong scintillations on an L-band signal are observed at higher latitudes. Conversely, when radar echoes are confined to only lower altitudes, weak scintillations are found and their latitudinal extent is small. During magnetically quiet periods, we have recorded plume type radar echoes during a post-midnight period that is devoid of L-band scintillations. Using spectral slopes and cross-correlation index of the VHF scintillation observations, we suggest that these irregularities could be "dead" or "fossil" bubbles which are just drifting in from west. This scenario is consistent with the observations where suppression of pre-reversal enhancement (PRE) in the eastward electric field is indicated by ionosonde observations of the height of equatorial F layer and also occurrence of low spectral width in the radar observations relative to pre-midnight period. However, absence of L-band scintillations during post-midnight event, when radar observed plume like structures and scintillations were recorded on VHF band, raises questions about the process of evolution of the irregularities. A possible explanation is that whereas small scale (∼3 m) irregularities are generated through secondary waves that grow on the walls of km scale size irregularities, in this case evolution of the Rayleigh-Taylor instability itself did not extend to irregularities of scale sizes of a few hundred meters that produce scintillation on a L-band signal
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