Recent Developments on Synthetic Jets (Review Paper)

<p>Synthetic jet is a form of pulsatile jet where the flow is synthesised from the ambient air and it does not need any external source as the flow is induced from the fluid existing around orifice/nozzle. This property makes synthetic jet unique compared to pulsatile and continuous jets. Recently, the synthetic jet is being widely used for flow control, mixing and heat transfer enhancement in aerospace applications. Focused on reviewing the recent developments on synthetic jet characterization and their applications resulting from the development of advanced diagnosing tools.</p>

Antimicrobial Activity and Phytochemical Constituents of Leaf Extracts of Cassia auriculata

Plants produce a wide variety of phytochemical constituents, which are secondary metabolites and are used either directly or indirectly in the pharmaceutical industry. 'For centuries, man has effectively used various components of plants or their extracts for the treatment of many diseases, including bacterial infections. In the present study methanol, chloroform and aqueous extracts of Cassia auriculata leaf were subjected for antimicrobial activity by well-diffusion method against six bacterial strains namely Bacillus cereus, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Proteus mirabilis. The results revealed that the methanol and chloroform extracts exhibited strong inhibitory activity against all the tested organisms (zone of inhibition of 12-20 mm), except Pseudomonas aeruginosa (zone of inhibition 10 mm or nil). The aqueous extracts showed moderate activity by 'Zone of inhibition ≤12 or nil). The extracts were screened for their phytochemical constituents by standard protocols' and were shown to contain carbohydrates, proteins, alkaloids, flavonoids, steroids, saponins and tannins. The antibacterial activity of these extracts is possibly linked to the presence of flavonoids, steroid, saponins and/or tannins. Further studies are needed to determine the precise active principles from Cassia auriculata.

Gender and ethnic differences in prevalence of self-reported insomnia among patients with obstructive sleep apnea

BACKGROUND

Insomnia and obstructive sleep apnea (OSA) are the two most common sleep disorders. Studies have shown that complaints of insomnia are prevalent among sleep clinic patients evaluated for OSA. Less is known about the gender and ethnic variations in this association.

OBJECTIVES

This paper aims to study the influence of gender and ethnicity in the prevalence of insomnia in patients with OSA and explore the association between these two disorders with an emphasis on psychophysiologic insomnia.

METHODS AND MEASUREMENTS

We reviewed case files, including self-reported questionnaires and polysomnography studies of 300 OSA patients [apnea-hypopnea index (AHI) of >10] from three ethnic groups--Caucasian, Hispanic, and African American, 50 patients each, male and female, seen at a tertiary care county hospital adult sleep center. Self-reported insomnia was classified as sleep onset insomnia, sleep maintenance insomnia, or insomnia with early morning awakening. Psychophysiologic insomnia was documented if the patient reported two of the following five symptoms: racing thoughts when trying to sleep, increased muscle tension when trying to sleep, fear of being unable to sleep, fear of being unable to fall back to sleep after waking up, and lying in bed worrying. Fischer exact tests for each contingency table were run using SPSS.

RESULTS

Among OSA patients, women were older, had higher body mass index, and lower AHI at the time of diagnosis, compared to men. Insomnia was more prevalent among patients with OSA (84%) than the reported 30% among general adult population. Sleep onset insomnia was reported more frequently by women (62%) than men (53%) (p = 0.03). Similarly self-reported psychophysiologic insomnia also showed a female preponderance (53% vs. 45%, p = 0.03). Caucasian women had the highest rate of self-reported sleep maintenance insomnia (80%). Hispanic women are more likely to complain of symptoms suggestive of psychophysiologic insomnia (58%).

CONCLUSIONS

There is a higher prevalence of insomnia in OSA patients. Ethnicity and gender possibly exhibit a complex and significant influence on the reported subtype of insomnia. Further larger studies may help confirm, as well as clarify, mechanisms that underlie the ethnic and gender differences that we have noted.

Photobacterium damselae ssp. damselae associated with diseased black tiger shrimp Penaeus monodon Fabricius in India

AIM

To characterize and identify Photobacterium damselae ssp. damselae present in black gill diseased Penaeus monodon collected from east coast of India.

METHODS AND RESULTS

Photobacterium damselae ssp. damselae was isolated from hepatopancreas, muscles and gills by using the thiosulfate citrate bile salts sucrose agar supplemented with 1.5% NaCl (TCBS-1) medium. A total of 32 Ph. damselae ssp. damselae isolates were studied together with two reference strains. The biochemical tests and analysis of ureC and 16S rRNA genes confirmed the phenotypic characterization of the isolates as Ph damselae ssp. damselae. Experimental infection studies revealed that the LD50 values of P. monodon and P. indicus ranged from 2x10(3) to 5x10(5) CFU per shrimp and from 4x10(2) to 2x10(4) CFU per shrimp, respectively.

CONCLUSIONS

Photobacterium damselae ssp. damselae was found in the internal organs of P. monodon and it showed pathogenic to shrimp.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first study on the Ph. damselae ssp. damselae present in the black gill diseased P. monodon in India and therefore might serve as a basis for future studies and diagnosis purpose to shrimp culturists.

Shrimp vaccination trials with the VP292 protein of white spot syndrome virus

AIMS

Construction of a recombinant vector that expresses VP292 protein of white spot syndrome virus (WSSV) and to exploit the possibility of obtaining the vaccine conferring protection against WSSV infection in shrimps.

METHODS AND RESULTS

VP292 protein of WSSV was amplified from WSSV genomic DNA by PCR. The target 814 bp amplified product specific for VP292 protein was inserted in to pQE30 expression vector. The recombinant plasmid of VP292 protein was transformed and expressed in Escherichia coli under induction of isopropyl-1-1-thio-beta-D-galactoside (IPTG) and the immunoreactivity of the fusion protein was detected by Western blot. Shrimp were vaccinated by intramuscular injection of the purified protein VP292 of WSSV and challenged for 0-30 days. Vaccination trial experiments show that two injections with recombinant VP292 (rVP292) protein induced a higher resistance, with 52% relative percentage survival value, in the shrimp at the 30th day postvaccination.

CONCLUSIONS

The expression system of protein VP292 of WSSV with a high efficiency has been successfully constructed. Vaccination trials show significant resistance in the shrimp vaccinated twice with recombinant VP292.

SIGNIFICANCE AND IMPACT OF THE STUDY

Results of this study prosper the development of WSSV protein vaccine against WSSV infection in shrimps.

In vitro susceptibility of antibiotics against Vibrio spp. and Aeromonas spp. isolated from Penaeus monodon hatcheries and ponds

Susceptibility patterns to 16 different antibiotics were investigated against pathogenic Vibrio spp. and Aeromonas spp. isolated from shrimp culture hatcheries and ponds in India. Thirteen species of Vibrio (N = 90) and two species of Aeromonas (N = 7) isolates were tested by agar disk diffusion. The results show that 100% of the isolates were resistant to ampicillin, and that 43.2% and 47.4% were sensitive to chlortetracycline and erythromycin, respectively. Susceptibility patterns of another 160 isolates belonging to the genera Vibrio and Aeromonas obtained from the water samples of shrimp hatcheries and ponds were tested against six commonly used antibiotics. Results indicate that isolates from the hatcheries were more resistant to antimicrobials than isolates from the ponds. The minimum inhibitory concentrations of five antibiotics against the different Vibrio spp. and Aeromonas spp. were determined. Ciprofloxacin was found to be the most effective in controlling the isolates from hatcheries and ponds compared with the other antibiotics used in the study. Our results reveal that antibiotic-resistant bacteria are widespread in the shrimp culture hatcheries and ponds in India. Potential risk to human health was not addressed in this study and remains to be elucidated.