Fortified relaxor ferroelectricity of rare earth substituted 4-layered BaBi3.9RE0.1Ti4O15 (RE = La, Pr, Nd, and Sm) Aurivillius compounds.

In this report, the effect of rare-earth (RE3+) ion substitution on structural, microstructural, and electrical properties in barium bismuth titanate (BaBi4Ti4O15) (BBTO) Aurivillius ceramics has been investigated. The Rietveld refinements on X-ray diffraction (XRD) patterns confirm that all the samples have an orthorhombic crystal system with A21am space group. Meanwhile, temperature dependent synchrotron XRD patterns reveal that the existence of dual phase in higher temperature region. The randomly oriented plate-like grains are experimentally strived to confirm the distinctive feature of bismuth layered Aurivillius ceramics. The broad band dielectric spectroscopic investigation signifies a shifting of ferroelectric phase transition (Tm) towards low temperature region with a decrease of the RE3+-ionic radii in BBTO ceramics. The origin of diffuse ferroelectric phase transitions followed by stabilization of the relaxor ferroelectric nature at high frequency region is explained using suitable standard models. The temperature dependent ac and dc conductivity results indicate the presence of double ionized oxygen vacancies in BBTO ceramics, whereas the dominance of single ionized oxygen vacancies is observed in RE-substituted BBTO ceramics. The room temperature polarization vs. electric field (P-E) hysteresis loops are shown to be well-shaped symmetric for BBTO ceramics, whereas slim asymmetric ferroelectric characteristics developed at RE-substituted BBTO ceramics.

Storage and recycling of major and trace element in mangroves.

The role of mangroves in sequestering metal and nutrients in sediment has been described in the past, but knowledge gaps still exist on storage capacity and recycling fluxes of elements in plant biomass, notably concerning their magnitude in root uptake and loss by litterfall. This study addresses the storage and transport pathways of 16 elements, classified as macro-nutrients (Ca, Mg, Na, K), micro-nutrients (Fe, Mn, Ni, Co, Cu, Cr, Zn, Mo), and potential toxicants (Al, Cd, Sn, Pb) in the world's largest mangroves, the Sundarbans. Elemental concentrations in plant organs were generally lower than in the sediment. The stock of macro and micro-nutrients in plant biomass varied from 60 to 2717 and 0.003 to 37.7 Mg ha-1 respectively, with highest values observed for Na and lowest for Cd. The Avicennia species exhibited the maximal accumulation of all elements. Translocation of major elements to different plant organs increased with increasing their concentrations in the sediment. Elemental loss via litterfall indicated that Sundarbans mangrove could act as a source, particularly of Mn, to the Bay of Bengal. Moreover, belowground uptake of the 16 elements showed 2-3 fold higher fluxes than their loss via litterfall. There was a significant retention of some trace elements (notably Mo, Cd, and Sn) in plant biomass, which might allow one to use these mangroves for phytoremediation and restoration purposes. We conclude that mangroves efficiently store and remobilize major and trace elements from the sediments by root uptake and recycle back to sediment surface via litterfall.

Fugitive dust emission control study for a developed smart dry fog system.

Air pollution due to dust emission is continuously increasing day by day in mining and allied industrial areas. Mining operations contribute a substantial amount of dust emission at the crushing, screening, and bulk material handling in loading areas. The ambient suspended dust particles create a severe nuisance to workers and local dwellers. For effective controlling of positive dust emission, an innovative automated dry fog dust suppression system (DFDSS) has been developed using hybrid nozzles, sensors, actuators, controllers, screw compressors, air receivers, pumps, motors, and water arrangement with filtration facility. The DFDSS was installed in a crushing and screening plant of an iron ore mine in India. Performance study indicted fugitive dust emission concentration values ranged from 354 to 7040 µg m-3, which was reduced to 91-300 µg m-3 after installation of DFDSS. The reduced values were within the permissible limit of 1200 µg m-3 at a distance of 25 ± 2 m in the predominant downwind direction. The installed DFDSS added a meager addition of moisture content of 0.032% in the handling iron ore material, which was below the acceptable limit of 0.1%. The DFDSS precisely regulated fugitive dust emission from various mining activities without affecting the minerals processing performance. Thus, the DFDSS can be implemented effectively in different mining and allied industries where there is a dust emission problem.

Efficacy of Mycophenolate Mofetil as a Remission Maintaining Agent in Idiopathic Childhood Nephrotic Syndrome.

Of all cases of idiopathic steroid-sensitive nephrotic syndrome (NS) in children, 40%-75% cases need long-term continuous steroids and/or other immunosuppressants to maintain remission, the effects of which on growth and renal function remain an issue of concern. The study aimed at exploring the safety and efficacy of mycophenolate mofetil (MMF) as a remission-maintaining agent in children with a diagnosis of frequent relapsing or steroid-dependent NS (FRNS/SDNS) requiring continuous medication for at least 1 year. Thirty-two children thus included received MMF (1000-1200 mg/m2/day) for 7 months along with tapering doses of oral prednisolone if it was being given from before with an attempt at tapering at 0.25 mg/kg/month ultimately stopping it altogether. Individuals were followed up for at least 5 more months after stopping MMF. Out of 32 children, 26 had SDNS and 6 had FRNS with male:female ratio being 2.2:1. The mean standard deviation (± SD) age of onset of disease was 2.72 ± 1.3 years and that entry to the study was 7.17 ± 2.2 years. Significant fall in number of relapses was observed following the introduction of MMF (110 in pre-MMF12 month period vs. 52 in post-MMF 12 months [p = 0.002]). The mean relapse rate/year/patient also decreased from 3.43 ± 1.26 to 1.62 ± 1.14 after entry in the study. Significant reduction of the cumulative dose of steroid regarding mean ± SD of mg/kg/year was also found following the introduction of MMF (190.9 ± 47.81 vs. 119.09 ± 60.09 [p = 0.001]). MMF is an efficacious agent in maintaining remission and reducing steroid requirement in children with FRNS and SDNS.

Location of multiple binding sites for testo and testo-Pt(II) with tRNA.

We report the binding of testo and testo-Pt(II) complexes (testosterone derivatives) with tRNA in aqueous solution at physiological pH. Thermodynamic parameter ΔH0 -8 to -3 (kJ mol-1), ΔS0 35 to 18 (J mol-1K-1) and ΔG0 -14 to -13 (kJ mol-1) and other spectroscopic results showed drug-tRNA binding occurs via ionic contacts with testo-Pt(II) forming more stable tRNA complexes in comparison to testo: Ktesto-Pt(II)-tRNA= 3.2 (± 0.9) × 105 M-1 > Ktesto-tRNA= 2.1 (± 0.7) × 105 M-1. Molecular modeling showed multiple binding sites for testo and testo-Pt(II) on tRNA molecule. Some of the useful molecular descriptors are calculated. Major structural changes were observed for biopolymers upon drug complexation, while tRNA remains in the A-family structures.

Sex differences in forebrain estrogen receptor regulation of hypoglycemic patterns of counter-regulatory hormone secretion and ventromedial hypothalamic nucleus glucoregulatory neurotransmitter and astrocyte glycogen metabolic enzyme expression.

The female ventromedial hypothalamic nucleus (VMN) is a focal substrate for estradiol (E) regulation of energy balance, feeding, and body weight, but how E shapes VMN gluco-regulatory signaling in each sex is unclear. This study investigated the hypothesis that estrogen receptor-alpha (ERα) and/or -beta (ERß) control VMN signals that inhibit [γ-aminobutyric acid] or stimulate [nitric oxide, steroidogenic factor-1 (SF-1)] counter-regulation in a sex-dependent manner. VMN nitrergic neurons monitor astrocyte fuel provision; here, we examined how these ER regulate astrocyte glycogen metabolic enzyme, monocarboxylate transporter, and adrenoreceptor protein responses to insulin-induced hypoglycemia (IIH) in each sex. Testes-intact male and E-replaced ovariectomized female rats were pretreated by intracerebroventricular ERα antagonist (MPP) or ERß antagonist (PHTPP) administration before IIH. Data implicate both ER in hypoglycemic inhibition of neuronal nitric oxide synthase protein in each sex and up-regulation of glutamate decarboxylase65/67 and SF-1 expression in females. ERα and -ß enhance astrocyte AMPK and glycogen synthase expression and inhibit glycogen phosphorylase in hypoglycemic females, while ERß suppresses the same proteins in males. Differential VMN astrocyte protein responses to IIH may partially reflect ERα and -ß augmentation of ERß and down-regulation of alpha1, alpha2, and beta1 adrenoreceptor proteins in females, versus ERß repression of GPER and alpha2 adrenoreceptor profiles in males. MPP or PHTPP pretreatment blunted counter-regulatory hormone secretion in hypoglycemic males only, suggesting that in males one or more VMN neurotransmitters exhibiting sensitivity to forebrain ER may passively regulate this endocrine outflow, whereas female forebrain ERα and -ß are apparently uninvolved in these contra-regulatory responses.

Chikungunya Infection: a Global Public Health Menace.

Chikungunya virus (CHIKV) has been involved in epidemics in African and Asian subcontinents and, of late, has transcended to affect the Americas. Aedes aegypti and Aedes albopictus are the major vectors for CHIKV infection, which results in dissemination of virus to various vital organs. Entry of virus into these tissues causes infiltration of innate immune cells, monocytes, macrophages, neutrophils, natural killer cells, and adaptive immune cells. Macrophages bearing the replicating virus, in turn, secrete pro-inflammatory cytokines IL-1ß, TNF-α, and IL-17. Together, this pro-inflammatory milieu induces osteoclastogenesis, bone loss, and erosion. CHIKV is characterized by fever, headache, myalgia, rash, and symmetric polyarthritis, which is generally self-limiting. In a subset of cases, however, musculoskeletal symptoms may persist for up to 3-5 years. Viral culture and isolation from blood cells of infected patients are the gold standards for diagnosis of CHIKV. In routine practice, however, assays for anti-CHIKV IgM antibodies are used for diagnosis, as elevated levels in blood of infected patients are noted from 10 days following infection for up to 3-6 months. Early diagnosis of CHIKV is possible by nucleic acid detection techniques. Treatment of acute CHIKV is mainly symptomatic, with analgesics, non-steroidal anti-inflammatory agents (NSAIDs), and low-dose steroids. No vaccines or anti-viral medicines have been approved for clinical therapy in CHIKV as yet. Hydroxychloroquine and methotrexate have been used in chronic CHIKV infection with variable success.

Controlled hypotension in day care functional endoscopic sinus surgery: A comparison between esmolol and dexmedetomidine: A prospective, double-blind, and randomized study.

BACKGROUND: Functional endoscopic sinus surgery (FESS) is the cornerstone of therapeutic management for nasal pathologies. This study is to compare the ability of preoperative and intraoperative esmolol versus dexmedetomidine for producing induced hypotension during FESS in adults in a day care setting. MATERIALS AND METHODS: Sixty patients (20-45 years) posted for FESS under general anesthesia were randomly divided into Group E (n = 30) receiving esmolol, loading dose 1 mg/kg over 1 min followed by 0.5 mg/kg/h infusion during maintenance and Group D (n = 30) receiving dexmedetomidine 1 µg/kg over 15 min before induction of anesthesia followed by 0.5 µg/Kg/h infusion during maintenance, respectively. Nasal bleeding and Surgeon's satisfaction score; amount and number of patients receiving fentanyl and nitroglycerine for analgesia and deliberate hypotension, Postanesthesia Care Unit (PACU) and hospital stay; hemodynamic parameters and side effects were recorded for each patient. RESULTS: Significantly less number and dosage of nitroglycerine was required (P = 0.0032 and 0.0001, respectively) in Group D compared to that in Group E. Again the number and dosage of patients requiring fentanyl were significantly lower in Group D. However, the duration of controlled hypotension was almost similar in both the groups. Group D patients suffered from significantly less nasal bleeding, and surgeon's satisfaction score was also high in this group. Discharge from PACU and hospital were significantly earlier in Group D. Intraoperative hemodynamics were quite comparable (P > 0.05) without any appreciable side effects. CONCLUSION: Dexmedetomidine found to be providing more effectively controlled hypotension and analgesia and thus allowing less nasal bleeding as well as more surgeons' satisfaction score.

A comparison between intrathecal clonidine and neostigmine as an adjuvant to bupivacaine in the subarachnoid block for elective abdominal hysterectomy operations: A prospective, double-blind and randomized controlled study.

BACKGROUND AND AIMS: Adjuvant to the local anesthetic agent has proven benefits when used intrathecally. With regards to intrathecal bupivacaine as control, we have compared in this study the effects of clonidine and neostigmine when co-administered intrathecally with hyperbaric (0.5%) bupivacaine for abdominal hysterectomy. MATERIALS AND METHODS: This prospective, randomized, double-blind study was conducted from May 2009 to June 2011. A total of 150 patients of American Society of Anaesthesiology grades I and II scheduled for abdominal hysterectomy under spinal anesthesia were randomly allocated into three groups. A volume of 3 ml of 0.5% hyperbaric bupivacaine was respectively added 1 ml solution containing 5% dextrose and 75 mcg of neostigmine in Group N, 1 ml containing 5% dextrose and 30 mcg of clonidine in Group C and 1 ml of 5% dextrose in Group D (control). We compared the sensory and motor block, the surgical condition, the duration of spinal analgesia and the side-effect profile. RESULTS AND OBSERVATIONS: Sensory and motor blocks and duration of spinal analgesia were significantly increased in both Group C and Group N compared to Group D. More incidences of Nausea and vomiting were observed in Group N compared to other groups. The surgical condition was poorer in Group N compared to Group C. CONCLUSION: Both intrathecal clonidine and neostigmine increase the bupivacaine-induced spinal block. However, clonidine provides better surgical condition and fewer incidences of nausea and vomiting.

Induced hypotension in ambulatory functional endoscopic sinus surgery: A comparison between dexmedetomidine and clonidine as premedication. A prospective, double-blind, and randomized study.

BACKGROUND: Functional endoscopic sinus surgery (FESS) is the mainstay of a therapeutic technique for nasal pathologies. This study is to compare the ability of preoperative dexmedetomidine versus clonidine for producing controlled hypotensive anesthesia during FESS in adults in an ambulatory care setting. MATERIALS AND METHODS: Sixty patients (25-50 years) posted for ambulatory FESS procedures under general anesthesia were randomly divided into Group C and D (n = 33 each) receiving dexmedetomidine 1 µg/kg and clonidine 1.5 µg/kg, respectively; both diluted in 100 ml saline solution 15 min before anesthetic induction. Nasal bleeding and surgeon's satisfaction score; amount and number of patients receiving fentanyl and nitroglycerine for analgesia and deliberate hypotension, duration of hypotension, post anesthesia care unit (PACU) and hospital stay; hemodynamic parameters and side effects were recorded for each patient. RESULTS: Number and dosage of nitroglycerine used was significantly (P = 0.034 and 0.0001 respectively) lower in Group D compared to that in Group C. Similarly, number of patients requiring fentanyl and dosage of same was significantly lower in Group D. But, the duration of controlled hypotension was almost similar in both the groups. Group D patients suffered from significantly less nasal bleeding and surgeon's satisfaction score was also high in this group. Discharge from PACU was significantly earlier in Group D, but hospital discharge timing was quite comparable among two groups. Intraoperative hemodynamics was significantly lower in Group D (P < 0.05) without any appreciable side effects. CONCLUSION: Dexmedetomidine found to be providing more effectively controlled hypotension and analgesia, and thus, allowing less nasal bleeding as well as more surgeons' satisfaction score.

Implication of organic matter on arsenic and antimony sequestration in sediment: evidence from Sundarban mangrove forest, India.

This study reports the measurement of stability constants for the interaction of As (V and III) and Sb (V and III) with humic substances extracted from aquatic sediments of the Sundarban mangrove forest ecosystem. It was observed that As and Sb formed a slightly more stable association with fulvic acid (FA) than with its humic acid (HA) counterpart. Quenching of fluorescence at increasing As (III and V) or Sb (III and V): FA or HA ratios was obtained that ideally correspond to a 1:1 complexation model. Quite strong complexation of As and Sb by FA and HA occurs at neutral pH, indicating that HA and FA probably markedly affect the mobility of As and Sb in the mangrove environment.

Nanostructures of Sr2+ doped BiFeO3 multifunctional ceramics with tunable photoluminescence and magnetic properties.

Careful tuning of formation (calcination) temperature of Sr(2+) doped BiFeO(3) multiferroic ceramics results in tailorable particle morphologies ranging from spherical to pillar-like. Based on the minimization of Gibb's free energy approach, the dominant homogeneous mechanism for particle growth is suggested. The chemical substitution of a trivalent ion (Bi(3+)) by a divalent ion (Sr(2+)) causes the transformation of certain fraction of Fe(3+) to Fe(4+) and/or the appearance of oxygen vacancies. This has been respectively proved by the analysis of XPS and refinement of neutron diffraction data. Although significant modification in the particle morphology is observed, the crystal unit cell remains rhombohedral with a R3c space group but interesting variations in physical properties are achieved. O-vacancies induced strong and sharp photoluminescence activity in the IR region, similar to ZnO, is reported for the first time. This observation opens up a new application for multiferroic ceramics. SQUID M-H data confirms the straightening of the canted spin structure of BiFeO(3), which in turn results in magnetism similar to ferromagnetic materials. Findings of the magneto-dielectric effect are also discussed to claim the multiferroic nature of the sample.

Recombinant activated factor VII for diffuse alveolar hemorrhage in microscopic polyangiitis.

Diffuse alveolar hemorrhage is a serious complication of the small vessel vasculitis syndromes and carries a high mortality. Recombinant activated factor VII (rFVIIa) is a powerful hemostatic agent developed for treatment of bleeding in patients with hemophilia and antibodies to factors VIII or IX. It has been used increasingly in life-threatening hemorrhage in a variety of other settings in which conventional medical or surgical therapy is unsuccessful. We report the successful use of rFVIIa for massive pulmonary hemorrhage in a patient of microscopic polyangiitis, which was later complicated by thrombotic microangiopathy and posterior reversible encephalopathy syndrome.

Prognostic markers in AIDS-related cryptococcal meningitis.

OBJECTIVE: Despite the advent and expanding access to antiretroviral therapy, HIV-associated cryptococcal meningitis (CM) remains a significant cause of mortality and morbidity amongst individuals with this infection in resource-limited settings. METHODS: We prospectively studied the clinical, biochemical and mycological parameters of 30 HIV patients diagnosed with cryptococcal meningitis at our centre over a period of 6 months with a view to identify prognostic factors predictive of poor outcome. RESULTS: Our study documented a mortality rate of 36.7%. Age, sex and previous diagnosis of HIV had no bearing on the survival outcome of patients. The study identified several poor prognostic factors including low GCS score, papilledema, elevated CSF opening pressure (>250 mm of H2O) and lack of regular HIV care in those with a prior diagnosis of HIV. CSF pleocytosis was significantly higher in the mortality group. CONCLUSION: There have been relatively few attempts to focus on poor prognostic markers associated with AIDS related Cryptococcal meningitis in Asian patients. Our study highlights how simple bedside clinical tools like ophthalmoscopy and CSF manometry can help in risk stratification in this group of patients.

Development of mixed inoculum for methane enriched biogas production.

Inocula were collected from four different sources such as Jajmau tannery waste treatment plant (ITW), Jajmau municipal waste treatment (IMW), Unnao distillery (IDW) and a batch reactor, in which the sludge of a field scale biogas reactor was added to cow dung slurry to develop inoculum (IBS). A combination of these mixed inocula were used for biogas production at 35°C in laboratory scale reactor (10 L capacity) and the average yield of biogas (0.547 Lg(-1) volatile solid (VS)) and methane (0.323 Lg(-1)VS) in 41 d was higher in case of mixed inoculum IMW (1) (IMW+IBS), with maximum methane content in biogas (68% during 27-30 d), as compared to other mixed inocula as well as control i.e. ITW (1) (ITW+IBS), IDW(1) (IDW+IBS) and IBS. The corresponding yields of gas were biogas (0.505, 0.536 and 0.456 Lg(-1)VS), methane (0.288, 0.305, and 0.245 Lg(-1)VS) where as, the corresponding maximum methane content in biogas was 62% during 29-33d, 64% during 29-33 d and 62% during 27-29 d in ITW(1), IDW(1) and IBS.

Biogeochemical controls of arsenic occurrence and mobility in the Indian Sundarban mangrove ecosystem.

This study aims to investigate the control of arsenic distribution by biogeochemical processes in the Indian Sundarban mangrove ecosystem and the importance of this ecosystem as an arsenic source for surrounding coastal water. The As(V)/As(III) ratio was found to be significantly lower in both surface and pore waters compared to sea water, which could be attributed to biogeochemical interconversion of these arsenic forms. The biological uptake of arsenic due to primary and benthic production occurs during the post-monsoon season, and is followed by the release of arsenic during the biochemical degradation and dissolution of plankton in the pre-monsoon season. These results suggest that arsenic is immobilized during incorporation into the arsenic-bearing initial phase, and unlikely to be released into pore water until the complete microbial degradation of arsenic-bearing organic compounds.

Compact multiwire proportional counters for the detection of fission fragments.

Two large area multistep position sensitive (two dimensional) multiwire proportional counters have been developed for experiments involving study of fission dynamics using general purpose scattering chamber facility at IUAC. Both detectors have an active area of 20x10 cm(2) and provide position signals in horizontal (X) and vertical (Y) planes, timing signal for time of flight measurements and energy signal giving the differential energy loss in the active volume. The design features are optimized for the detection of low energy heavy ions at very low gas pressures. Special care was taken in setting up the readout electronics, constant fraction discriminators for position signals in particular, to get optimum position and timing resolutions along with high count rate handling capability of low energy heavy ions. A custom made charge sensitive preamplifier, having lower gain and shorter decay time, has been developed for extracting the differential energy loss signal. The position and time resolutions of the detectors were determined to be 1.1 mm full width at half maximum (FWHM) and 1.7 ns FWHM, respectively. The detector could handle heavy ion count rates exceeding 20 kHz without any breakdown. Time of flight signal in combination with differential energy loss signal gives a clean separation of fission fragments from projectile and target like particles. The timing and position signals of the detectors are used for fission coincidence measurements and subsequent extraction of their mass, angular, and total kinetic energy distributions. This article describes systematic study of these fission counters in terms of efficiency, time resolution, count rate handling capability, position resolution, and the readout electronics. The detector has been operated with both five electrode geometry and four electrode geometry, and a comparison has been made in their performances.

Quantification of bone mineral density to define osteoporosis in rat.

The diagnosis of osteoporosis centers on assessment of bone mass and quality. In the absence of evidence-based guidelines to assess bone status in laboratory animals and unsuitability of use of T-/Z-scores meant for clinical application in animal studies, most investigators involved in new drug research and development employ clinical biomarkers and kits to assess bone turnover rate and portray change in bone mineral density (BMD) as percentage of increase/decrease, making comparative assessment of the effect highly impractical. This study proposes threshold boundaries of BMD (rT-score) in colony-bred Sprague-Dawley rats, distinct from those used clinically. Boundaries were obtained keeping fixed Type-I error (alpha=0.025). Femur neck was considered best for defining bone status using BMD measured by dual-energy X-ray absorptiometry. Findings demonstrate that BMD-1.96 and <-0.80 rT-score as osteopenia. Performance of boundaries to ascertain bone status was examined through simulation under different physiological/ hormonal states viz. estrogen deficiency, ageing, estrus cycle, pregnancy, and lactation. The Area Under the Receiver Operating Characteristic curve of 0.98 obtained using BMD of femur neck, being close to unity, shows excellent ability of the proposed rT-score to effectively identify osteoporosis. Further studies using certain hierarchical measures of bone quality such as histomorphometry, mechanical testing etc. could supplement these findings. Since, unlike humans, most laboratory animals including rats only exhibit osteopenia and do not fracture their bones, the proposed thresholds are intended to serve as categorical tools to define bone quality and not to predict fracture risk.

Biocontrol efficiency of odonate nymphs against larvae of the mosquito, Culex quinquefasciatus Say, 1823.

An estimation of the predatory efficiency of the nymphs of five coexisting odonate species Aeshna flavifrons, Coenagrion kashmirum, Ischnura forcipata, Rhinocypha ignipennis and Sympetrum durum using the fourth-instar larvae of Culex quinquefasciatus as prey, was made under laboratory and semi-field conditions. The daily feeding rate varied among the odonate species, at laboratory conditions. The mean number of IV instars Cx. quinquefasciatus larvae killed per day, ranged between 14 and 64 (64 mosquito larvae for I. forcipata, 57 for A. flavifrons, 45 for R. ignipennis, 25 for S. durum and 14 for C. kashmirum). The prey consumption was linearly related to the number of predators and prey available but inversely related with space. It was also noted that the feeding rates varied significantly between dark and light conditions, in all the odonate species. The presence of nymphs in semi-field conditions significantly lowered the mosquito larval density in dipper samples after 15 days from the introduction, followed by a significant increase of larval mosquito density after 15 days from the withdrawal of the nymphs. The results of the present observations are suggestive of the use of odonate nymphs in temporary pools or larger habitats where they can be a potential biological resource in regulating the larval population of the vector and pest mosquitoes.