50 research outputs found
Study of Distribution and Asymmetry of Solar Active Prominences During Solar Cycle 23
In this paper we present the results of a study of the spatial distribution
and asymmetry of solar active prominences (SAP) for the period 1996-2007 (solar
cycle 23). For more meaningful statistical analysis we have analysed the
distribution and asymmetry of SAP in two subdivisions viz. Group1 (ADF, APR,
DSF, CRN, CAP) and Group2 (AFS, ASR, BSD, BSL, DSD, SPY, LPS). The north-south
(N-S) latitudinal distribution shows that the SAP events are most prolific in
the 21-30degree slice in the northern and southern hemispheres and east-west
(E-W) longitudinal distribution study shows that the SAP events are most
prolific (best visible) in the 81-90degree slice in the eastern and western
hemispheres. It has been found that the SAP activity during this cycle is low
compared to previous solar cycles. The present study indicates that during the
rising phase of the cycle the number of SAP events were roughly equal on the
north and south hemispheres. However, activity on the southern hemisphere has
been dominant since 1999. Our statistical study shows that the N-S asymmetry is
more significant then the E-W asymmetry.Comment: 21 pages 5 figures; Published online; 02 October, 2009; Solar Physics
Journa
Critical Role of IRF-5 in the Development of T helper 1 responses to Leishmania donovani infection
The transcription factor Interferon Regulatory Factor 5 (IRF-5) has been shown to be involved in the induction of proinflammatory cytokines in response to viral infections and TLR activation and to play an essential role in the innate inflammatory response. In this study, we used the experimental model of visceral leishmaniasis to investigate the role of IRF-5 in the generation of Th1 responses and in the formation of Th1-type liver granulomas in Leishmania donovani infected mice. We show that TLR7-mediated activation of IRF-5 is essential for the development of Th1 responses to L. donovani in the spleen during chronic infection. We also demonstrate that IRF-5 deficiency leads to the incapacity to control L. donovani infection in the liver and to the formation of smaller granulomas. Granulomas in Irf5-/- mice are characterized by an increased IL-4 and IL-10 response and concomitant low iNOS expression. Collectively, these results identify IRF-5 as a critical molecular switch for the development of Th1 immune responses following L. donovani infections and reveal an indirect role of IRF-5 in the regulation of iNOS expression
Critical Role of IRF-5 in the Development of T helper 1 responses to Leishmania donovani infection
The transcription factor Interferon Regulatory Factor 5 (IRF-5) has been shown to be involved in the induction of proinflammatory cytokines in response to viral infections and TLR activation and to play an essential role in the innate inflammatory response. In this study, we used the experimental model of visceral leishmaniasis to investigate the role of IRF-5 in the generation of Th1 responses and in the formation of Th1-type liver granulomas in Leishmania donovani infected mice. We show that TLR7-mediated activation of IRF-5 is essential for the development of Th1 responses to L. donovani in the spleen during chronic infection. We also demonstrate that IRF-5 deficiency leads to the incapacity to control L. donovani infection in the liver and to the formation of smaller granulomas. Granulomas in Irf5-/- mice are characterized by an increased IL-4 and IL-10 response and concomitant low iNOS expression. Collectively, these results identify IRF-5 as a critical molecular switch for the development of Th1 immune responses following L. donovani infections and reveal an indirect role of IRF-5 in the regulation of iNOS expression
Regulation of immunity during visceral Leishmania infection
Unicellular eukaryotes of the genus Leishmania are collectively responsible for a heterogeneous group of diseases known as leishmaniasis. The visceral form of leishmaniasis, caused by L. donovani or L. infantum, is a devastating condition, claiming 20,000 to 40,000 lives annually, with particular incidence in some of the poorest regions of the world. Immunity to Leishmania depends on the development of protective type I immune responses capable of activating infected phagocytes to kill intracellular amastigotes. However, despite the induction of protective responses, disease progresses due to a multitude of factors that impede an optimal response. These include the action of suppressive cytokines, exhaustion of specific T cells, loss of lymphoid tissue architecture and a defective humoral response. We will review how these responses are orchestrated during the course of infection, including both early and chronic stages, focusing on the spleen and the liver, which are the main target organs of visceral Leishmania in the host. A comprehensive understanding of the immune events that occur during visceral Leishmania infection is crucial for the implementation of immunotherapeutic approaches that complement the current anti-Leishmania chemotherapy and the development of effective vaccines to prevent disease.The research leading to these results has received funding from the European Community’s Seventh Framework Programme under grant agreement No.602773 (Project KINDRED). VR is supported by a post-doctoral fellowship granted by the KINDReD consortium. RS thanks the Foundation for Science and Technology (FCT) for an Investigator Grant (IF/00021/2014). This work was supported by grants to JE from ANR (LEISH-APO, France), Partenariat Hubert Curien (PHC) (program Volubilis, MA/11/262). JE acknowledges the support of the Canada Research Chair Program
Comparative evaluation of possible ocular photochemical toxicity of fluoroquinolones meant for ocular use in experimental models
387-391Fluoroquinolones (FQs) are
extensively used in bacterial keratitis and other intraocular infections. Since
eye is constantly exposed to light, incidence of ocular phototoxicity due to
commonly used FQs is of great interest for their safe use. Phototoxicity of
commonly used FQs (ciprofloxacin, lomefloxacin, pefloxacin, ofloxacin,
sparfloxacin and gatifloxacin), has been evaluated by using HET-CAM-UV model
(Photo Hen Egg Test-C Chorioallantoic Membrane model). This study was further
extended by adding lomefloxacin dissolved in bovine vitreous (0.5ml) on the
chorioallantoic membrane (CAM). Using a standard scale, the phototoxic damage
was assessed at different time intervals. Respective controls were kept in dark
to distinguish the toxicity of the drugs per
se. The results showed that the phototoxicity induced by lomefloxacin was
very high followed by gatifloxacin and sparfloxacin and least for other drugs
studied. Interestingly, lomefloxacin along with vitreous showed significantly
low phototoxicity. This could be due to the antioxidant property of ascorbic
acid present in the vitreous
Not Available
Not AvailableTo VL Gehun 953- a high yielding variety was released by Uttarakhand
seed Sub-Committee and notified by Central Sub-Committee on Crop
Standards, Notification and Release of Variety for commercial cultivation
under irrigated inorganic production conditions of Uttarakhand Plains
and timely sown irrigated organic production situations of Uttarakhand
hills. It recorded (3.34 tha-1) 7.46% higher grain yield compared to
the best check VL Gehun 907 under irrigated organic conditions of
Uttarakhand hills. Likewise, it produced (4.47 tha-1) 6.93% higher grain
yield compared to the best check PBW 343 under irrigated situations
of Uttarakhand Plains. It provided greater level of resistance to both
stripe and leaf rust and recorded average coefficient of infection (ACI)
of 0.27 for stripe rust and 2.0 for leaf rust under artificial inoculation
situations, respectively. It contains 10.4 % average protein and 82.8
kghl-1 hectoliter weight, therefore, possessing good quality for chapatti
making with good flour recovery. The large scale demonstrations
conducted in different districts of Uttarakhand has proved its
acceptability among the farmers. The spread of this variety in entire
Uttarakhand state (Hills under organic and Plains under inorganic
conditions) is anticipated to enhance wheat productivity of the state.
In addition, it would also help in curtailing the rust inoculum both in
hills as well as plains of Uttarakhand owing to its better resistance.Not Availabl