97 research outputs found
Selective Breeding and Development of Disease Resistant Broodstock of Black Tiger Shrimp Penaeus monodon Fabricius, 1798
The Indian tiger shrimp Penaeus monodon is the
principal species being cultured. Of late hatchery sector
is being dependent on wild gravid females due to non
response of broodstock to eyestalk ablation. High cost of
gravid females compelling the grow-out sector to stock
pathogen carrier seeds. Hence domestication of tiger
shrimp is essential to produce Specific Pathogen Free
(SPF) broodstock / Disease Resistant (DR) broodstock.
Merits and demerits of SPF versus DR broodstock are
presented. Development of SPF broodstock involves
stringent management of environment to arrest the entry
of pathogens and more than one economic trait can be
selected. Whereas in development of DR broodstockanimals are challenged with the pathogen and a selection
of other economic traits are less possible. Resistance in
shrimp exists at the species level as well as individual
level. Experiment on domestication of P. monodon in
which programme was advanced up to F3 generation has
revealed the existence of resistance for WSSV at the
individual level. Selective breeding programme for
development of D R broodstock involves development
of disease free base population, forming them into
families, production of F1
generation family wise through
inbreeding, challenging each family with WSSV at 3-5 g
size and rearing survived individuals up to 100 g size,
production of F2
generation by random inter crossing
between families, advancing the programme up to F5
generation. Development of DR broodstock is imperative
to ensure sustainable shrimp productio
Radiating dipoles in photonic crystals
The radiation dynamics of a dipole antenna embedded in a Photonic Crystal are
modeled by an initially excited harmonic oscillator coupled to a non--Markovian
bath of harmonic oscillators representing the colored electromagnetic vacuum
within the crystal. Realistic coupling constants based on the natural modes of
the Photonic Crystal, i.e., Bloch waves and their associated dispersion
relation, are derived. For simple model systems, well-known results such as
decay times and emission spectra are reproduced. This approach enables direct
incorporation of realistic band structure computations into studies of
radiative emission from atoms and molecules within photonic crystals. We
therefore provide a predictive and interpretative tool for experiments in both
the microwave and optical regimes.Comment: Phys. Rev. E, accepte
Measurement and analysis of photonuclear reactions on thick target samples of biological importance
A novel method for quantification of trace elements in herbal samples using photon activation analysis is reported. Seven trace elements have been detected and their concentrations have been estimated from residue yields after the photo-nuclear reaction. This method can complement the conventional neutron activation analysis for trace elemental detection. The data is useful for setting referral standards for quality assurance of herbs and herbal formulations commercially available for therapeutic purposes. This is a relatively simple, novel and sensitive method for trace elemental analysis which can be scaled to suit industrial and statutory requirements of standardization and quality control
Measurement and analysis of photonuclear reactions on thick target samples of biological importance
404-408A novel method for quantification of trace elements in herbal samples using photon activation analysis is reported. Seven trace elements have been detected and their concentrations have been estimated from residue yields after the photo-nuclear reaction. This method can complement the conventional neutron activation analysis for trace elemental detection. The data is useful for setting referral standards for quality assurance of herbs and herbal formulations commercially available for therapeutic purposes. This is a relatively simple, novel and sensitive method for trace elemental analysis which can be scaled to suit industrial and statutory requirements of standardization and quality control
Prawn fauna (Crustacea: Decapoda) of India - An annotated checklist of the Penaeoid, Sergestoid, Stenopodid and Caridean prawns
Twenty four species of Pandalid shrimps reported from the
Indian waters, of which six genera (Chlorotocella, Chlorotocus,
Chlorocurtis, Dorodotes, Heterocarpoides and Stylopandalus)
are represented by single species each. The genera, Plesionika
and Heterocarpus are represented by eleven and seven species
respectively. Plesionika adensameri (Balss, 1914) a deep-sea
shrimp hitherto unreported from Indian waters is recorded from
west coast of India. Information on some biological aspects of
few Pandalid shrimps from Indian waters is also reported in the
present paper
Delineation of Diverse Macrophage Activation Programs in Response to Intracellular Parasites and Cytokines
Macrophages are a type of immune cell that engulf and digest microorganisms. Despite their role in protecting the host from infection, many pathogens have developed ways to hijack the macrophage and use the cell for their own survival and proliferation. This includes the parasites Trypanosoma cruzi and Leishmania mexicana. In order to gain further understanding of how these pathogens interact with the host macrophage, we compared macrophages that have been infected with these parasites to macrophages that have been stimulated in a number of different ways. Macrophages can be activated by a wide variety of stimuli, including common motifs found on pathogens (known as pathogen associated molecular patterns or PAMPs) and cytokines secreted by other immune cells. In this study, we have delineated the relationships between the macrophage activation programs elicited by a number of cytokines and PAMPs. Furthermore, we have placed the macrophage responses to T. cruzi and L. mexicana into the context of these activation programs, providing a better understanding of the interactions between these pathogens and macrophages
Effects of sub-lethal single, simultaneous, and sequential abiotic stresses on phenotypic traits of Arabidopsis thaliana
Plant responses to abiotic stresses are complex and dynamic, and involve changes in different traits, either as the direct consequence of the stress, or as an active acclimatory response. Abiotic stresses frequently occur simultaneously or in succession, rather than in isolation. Despite this, most studies have focused on a single stress and single or few plant traits. To address this gap, our study comprehensively and categorically quantified the individual and combined effects of three major abiotic stresses associated with climate change (flooding, progressive drought and high temperature) on 12 phenotypic traits related to morphology, development, growth and fitness, at different developmental stages in four Arabidopsis thaliana accessions. Combined sub-lethal stresses were applied either simultaneously (high temperature and drought) or sequentially (flooding followed by drought). In total, we analyzed the phenotypic responses of 1782 individuals across these stresses and different developmental stages. Overall, abiotic stresses and their combinations resulted in distinct patterns of effects across the traits analyzed, with both quantitative and qualitative differences across accessions. Stress combinations had additive effects on some traits, whereas clear positive and negative interactions were observed for other traits: 9 out of 12 traits for high temperature and drought, 6 out of 12 traits for post-submergence and drought showed significant interactions. In many cases where the stresses interacted, the strength of interactions varied across accessions. Hence, our results indicated a general pattern of response in most phenotypic traits to the different stresses and stress combinations, but it also indicated a natural genetic variation in the strength of these responses. Overall, our study provides a rich characterization of trait responses of Arabidopsis plants to sub-lethal abiotic stresses at the phenotypic level and can serve as starting point for further in-depth physiological research and plant modelling efforts
Suitability of external controls for drug evaluation in Duchenne muscular dystrophy
OBJECTIVE: To evaluate the suitability of real-world data (RWD) and natural history data (NHD) for use as external controls in drug evaluations for ambulatory Duchenne muscular dystrophy (DMD). METHODS: The consistency of changes in the 6-minute walk distance (Δ6MWD) was assessed across multiple clinical trial placebo arms and sources of NHD/RWD. Six placebo arms reporting 48-week Δ6MWD were identified via literature review and represented 4 sets of inclusion/exclusion criteria (n = 383 patients in total). Five sources of RWD/NHD were contributed by Universitaire Ziekenhuizen Leuven, DMD Italian Group, The Cooperative International Neuromuscular Research Group, ImagingDMD, and the PRO-DMD-01 study (n = 430 patients, in total). Mean Δ6MWD was compared between each placebo arm and RWD/NHD source after subjecting the latter to the inclusion/exclusion criteria of the trial for baseline age, ambulatory function, and steroid use. Baseline covariate adjustment was investigated in a subset of patients with available data. RESULTS: Analyses included ∼1,200 patient-years of follow-up. Differences in mean Δ6MWD between trial placebo arms and RWD/NHD cohorts ranged from -19.4 m (i.e., better outcomes in RWD/NHD) to 19.5 m (i.e., worse outcomes in RWD/NHD) and were not statistically significant before or after covariate adjustment. CONCLUSIONS: We found that Δ6MWD was consistent between placebo arms and RWD/NHD subjected to equivalent inclusion/exclusion criteria. No evidence for systematic bias was detected. These findings are encouraging for the use of RWD/NHD to augment, or possibly replace, placebo controls in DMD trials. Multi-institution collaboration through the Collaborative Trajectory Analysis Project rendered this study feasible
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