23 research outputs found
D-brane Bound States from Charged Macroscopic Strings
We construct new D-brane bound states using charged macroscopic type IIB
string solutions.A generic bound state solution, when dimensionally reduced,
carries multiple gauge charges. Starting with D=9 charged macroscopic strings,
we obtain solutions in D=10, which are interpreted as carrying (F, D0, D2)
charges as well as nonzero momenta. The masses and charges are also explicitly
shown to satisfy the non-threshold bound of 1/2 BPS objects. Our solutions
reduce to the known D-brane bound state solutions with appropriate restrictions
in the parameter space. We further generalize the results to (Dp- D(p+2)) bound
state in IIA/B theories, giving an explicit example with p=1.Comment: 21 pages, latex, few references added: minor modification
A Note on D-brane - Anti-D-brane Interactions in Plane Wave Backgrounds
We study aspects of the interaction between a D-brane and an anti-D-brane in
the maximally supersymmetric plane wave background of type IIB superstring
theory, which is equipped with a mass parameter mu. An early such study in flat
spacetime (mu=0) served to sharpen intuition about D-brane interactions,
showing in particular the key role of the ``stringy halo'' that surrounds a
D-brane. The halo marks the edge of the region within which tachyon
condensation occurs, opening a gateway to new non-trivial vacua of the theory.
It seems pertinent to study the fate of the halo for non--zero mu. We focus on
the simplest cases of a Lorentzian brane with p=1 and an Euclidean brane with
p=-1, the D--instanton. For the Lorentzian brane, we observe that the halo is
unaffected by the presence of non--zero mu. This most likely extends to other
(Lorentzian) p. For the Euclidean brane, we find that the halo is affected by
non-zero mu. As this is related to subtleties in defining the exchange
amplitude between Euclidean branes in the open string sector, we expect this to
extend to all Euclidean branes in this background.Comment: 14 pages, LaTeX, 2 eps figures. v2: a reference and some clarifying
remarks added; v3: Considerably revised version; halo unaffected by plane
wave background for Lorentzian branes, but Euclidean branes' halo is modifie
Supersymmetric Intersections of M-branes and pp-waves
We study supersymmetric intersections of M2 and M5 branes with different
pp-waves of M-theory. We consider first M-brane probes in the background of
pp-waves and determine under which conditions the embedding is supersymmetric.
We particularize our formalism to the case of pp-waves with 32, 24 and 20
supersymmetries. We also construct supergravity solutions for the brane-wave
system. Generically these solutions are delocalised along some directions
transverse to the brane and preserve the same number of supersymmetries as in
the brane probe approach.Comment: 41 pages, LaTeX; v2 references adde
A global research priority agenda to advance public health responses to fatty liver disease
Background & aims
An estimated 38% of adults worldwide have non-alcoholic fatty liver disease (NAFLD). From individual impacts to widespread public health and economic consequences, the implications of this disease are profound. This study aimed to develop an aligned, prioritised fatty liver disease research agenda for the global health community.
Methods
Nine co-chairs drafted initial research priorities, subsequently reviewed by 40 core authors and debated during a three-day in-person meeting. Following a Delphi methodology, over two rounds, a large panel (R1 n = 344, R2 n = 288) reviewed the priorities, via Qualtrics XM, indicating agreement using a four-point Likert-scale and providing written feedback. The core group revised the draft priorities between rounds. In R2, panellists also ranked the priorities within six domains: epidemiology, models of care, treatment and care, education and awareness, patient and community perspectives, and leadership and public health policy.
Results
The consensus-built fatty liver disease research agenda encompasses 28 priorities. The mean percentage of ‘agree’ responses increased from 78.3 in R1 to 81.1 in R2. Five priorities received unanimous combined agreement (‘agree’ + ‘somewhat agree’); the remaining 23 priorities had >90% combined agreement. While all but one of the priorities exhibited at least a super-majority of agreement (>66.7% ‘agree’), 13 priorities had 90% combined agreement.
Conclusions
Adopting this multidisciplinary consensus-built research priorities agenda can deliver a step-change in addressing fatty liver disease, mitigating against its individual and societal harms and proactively altering its natural history through prevention, identification, treatment, and care. This agenda should catalyse the global health community’s efforts to advance and accelerate responses to this widespread and fast-growing public health threat.
Impact and implications
An estimated 38% of adults and 13% of children and adolescents worldwide have fatty liver disease, making it the most prevalent liver disease in history. Despite substantial scientific progress in the past three decades, the burden continues to grow, with an urgent need to advance understanding of how to prevent, manage, and treat the disease. Through a global consensus process, a multidisciplinary group agreed on 28 research priorities covering a broad range of themes, from disease burden, treatment, and health system responses to awareness and policy. The findings have relevance for clinical and non-clinical researchers as well as funders working on fatty liver disease and non-communicable diseases more broadly, setting out a prioritised, ranked research agenda for turning the tide on this fast-growing public health threat
Not Available
Not AvailableBiofloc (BFT) based nursery rearing system help provides an additional food source, healthy juvenile production with better survival and an avenue for nitrogen removal through eco-friendly approach. It should be cost and energy efficient with a quick turn over. However, many questions remain unanswered regarding mechanisms of action and induced antibacterial/antiviral immune responses in penaeid shrimp especially during nursery phase. The present experiment was designed to evaluate the effects of biofloc treatments generated and maintained through three approaches on growth performances, physico-chemical parameters, microbial dynamics, feed utilization and immunological assessments in P. vannamei nursery rearing. The experiment was conducted in 500 L FRP tanks stocked with PL-III stage of Pacific white shrimp for 30 days at a stocking density of 6000 nos/m3. The heterotrophic bacteria level of 1 × 107 CFU/ml was maintained through three approaches differing in their generation; (1) biofloc lyophilized powder (BFP), (2) biofloc matured water (BFW) and (3) biofloc consortium (BFC) and compared with that of the conventional nursery rearing without biofloc treatment (Control). BFT treatments showed significantly higher growth as observed in average body weight (ABW) (BFP - 0.357 g, BFW - 0.363 g & BFC - 0.391 g) compared to control (0.188 g). BFT groups showed significantly (P < 0.01) higher survival (BFP (81.47%), BFW (79.73%), and BFC (85.4%)), than control groups. The population of heterotrophic bacteria was significantly (P < 0.05) increased in treatments when compared to control. But higher Vibrio load was recorded in the control than BFT water samples. BFT based nursery rearing system improves the water quality parameters when compared to the control. The cumulative mortality rate of biofloc reared juveniles was significantly lowered when challenged with Vibrio whereas, in control, it was higher. Further, certain immune genes like the prophenoloxidase, crustin, MAS, serine protease, alpha-2-M, antiviral genes, and RAN were up-regulated in the BFT groups. All these findings indicate that BFT nursery rearing system gives optimal and better culture condition displaying better survival, growth, disease tolerance, immune activity during the nursery phase and can be managed with minimal water exchange and maximum biosecurity.Not Availabl
Not Available
Not AvailableEffect of bio-augmentation of Bacillus spp in biofloc on growth, survival and immunity in Indian white shrimp
Penaeus indicus was evaluated. Nine Bacillus strains were isolated and screened individually as well as in the form
of a consortia. To maintain a C:N ratio of 12:1 a blend of carbohydrate sources was used. Bio-augmentation with
bacterial consortium and Virgibacillus sp. produced improved growth and immunity. Shrimp survival ranged
from 80 to 95% among treatments. Production was higher (35%) in the biofloc tanks with an average body
weight (ABW) of 10.89 ± 1.2 g. On evaluating the immune responses, it was found that trypsin significantly
(P < 0.05) enhanced Prophenoloxidase (PO) activity in Lysinibacillus, Bacillus cereus, Bacillus licheniformis and
Bacillus subtilis bio-augmented groups. Laminarin induced PO activity was observed in groups supplemented with
Oceanobacillus sp., Bacillus sp.and Bacillus megaterium. The lysozyme (LZ) activity was significantly (P < 0.05)
higher in B. cereus and Microbial Consortia (MC), while other treatments were less effective. Total hemocyte
count (THC) significantly (P < 0.05) increased in all treatment groups compared to the control. Hyaline hemocyte
(HH) count was significantly (P < 0.05) higher in the control group (14.43%). Semi granular hemocytes
(SGH) was higher in groups treated with Lysinibacillus, Bacillus sp., B. licheniformis and B. subtilis. The granular
hemocyte (GH) count was significantly (P < 0.05) higher in Virgibacillus sp., B. cereus, B.megaterium and
Oceanobacillus sp. The biofloc alone (BF), treated and augmented with B. megaterium significantly (P < 0.05)
increased phagocytic activity. Highly significant phagocytic index (PI) was observed in bio-augmented groups,
BF and MC. The relative expression levels of immune genes were found to be significantly up-regulated in
shrimps grown in bio-augmented groups. Enhanced immunological parameters implies that bio-augmentation of biofloc with Bacillus spp. improved immunity in shrimps. Hence, bio-augmentation of probiotics in biofloc may
be useful in improving culture conditions to produce P. indicus.Not Availabl
Not Available
Not AvailableShrimp aquaculture demands technological advancement that boosts production and environmental sustainability. This study evaluated and compared the growth performance and innate immunity of two species of shrimp (Pacific White shrimp Penaeus vannamei and India white shrimp Penaeus indicus) reared under biofloc technology with different dietary protein levels (Low-25%, Medium-30% and High-35%). As prophenoloxidase (proPO) activity is an important parameter in immune response of shrimp, we focused on the dynamics of prophenoloxidase induced by three different activators (Sodium dodecyle sulfate, (SDS, Trypsin & Laminarin)). At the end of the experiment, the effect of activators on proPO activity in serum, plasma and hemocyte lysate (HLS) was evaluated in both the species under conventional and biofloc systems with graded proteins. This experiment lasted for a month as nursery rearing followed by 60 days of grow-out culture. There was no significant difference (p < 0.05) in growth performances of both the species reared under biofloc, whereas control group exhibited lower growth. Significantly higher average body weight (ABW), survival and specific growth rate (SGR) were observed in medium protein groups reared under biofloc than the other biofloc groups and control. The medium protein groups also showed significantly lower (p < 0.01) TAN, NO2–N, and NO3–N levels compared to other treatments and the control exhibited considerably higher TAN, NO2–N and NO3–N levels. The proPO activity in serum of both the shrimps were found to be significantly higher (p < 0.05) than the control in which highest proPO activity was observed in SDS activated groups irrespective of the graded protein levels. A similar trend was observed in the plasma of P. indicus in which SDS activated group fed with high protein level showed highest proPO activity, whereas in plasma of P. vannamei trypsin activated groups fed with low protein level showed higher proPO activity than SDS and laminarin activated groups. The HLS of P. vannamei showed highest proPO functioning in trypsin activated group fed with high protein level, whereas in P. indicus, the highest proPO activity was observed in SDS activated group fed with high protein diet. Though in many cases, the groups fed with high protein diet showed highest proPO activity, the low protein and the medium protein groups also exhibited upregulation in the immune response parameter reared under biofloc irrespective of the species. SOD activity of the hemocytes were influenced by different dietary protein levels and better inhibition was observed in HP when compared to control and other treated groups. Thus the native non-SPF Indian white shrimp P. indicus has comparable potential as the SPF Pacific white shrimp P. vannamei in terms of innate immunity, immune response, and growth when reared under biofloc conditions.Not Availabl
Not Available
Not AvailableShrimp aquaculture demands technological advancement that boosts production and environmental sustainability.
This study evaluated and compared the growth performance and innate immunity of two species of
shrimp (Pacific White shrimp Penaeus vannamei and India white shrimp Penaeus indicus) reared under biofloc
technology with different dietary protein levels (Low-25%, Medium-30% and High-35%). As prophenoloxidase
(proPO) activity is an important parameter in immune response of shrimp, we focused on the dynamics of
prophenoloxidase induced by three different activators (Sodium dodecyle sulfate), (SDS, Trypsin & Laminarin). At
the end of the experiment, the effect of activators on proPO activity in serum, plasma and hemocyte lysate (HLS)
was evaluated in both the species under conventional and biofloc systems with graded proteins. This experiment
lasted for a month as nursery rearing followed by 60 days of grow-out culture. There was no significant difference
(p < 0.05) in growth performances of both the species reared under biofloc, whereas control group
exhibited lower growth. Significantly higher average body weight (ABW), survival and specific growth rate
(SGR) were observed in medium protein groups reared under biofloc than the other biofloc groups and control.
The medium protein groups also showed significantly lower (p < 0.01) TAN, NO2–N, and NO3–N levels compared
to other treatments and the control exhibited considerably higher TAN, NO2–N and NO3–N levels. The
proPO activity in serum of both the shrimps were found to be significantly higher (p < 0.05) than the control in
which highest proPO activity was observed in SDS activated groups irrespective of the graded protein levels. A
similar trend was observed in the plasma of P. indicus in which SDS activated group fed with high protein level
showed highest proPO activity, whereas in plasma of P. vannamei trypsin activated groups fed with low protein
level showed higher proPO activity than SDS and laminarin activated groups. The HLS of P. vannamei showed
highest proPO functioning in trypsin activated group fed with high protein level, whereas in P. indicus, the
highest proPO activity was observed in SDS activated group fed with high protein diet. Though in many cases,
the groups fed with high protein diet showed highest proPO activity, the low protein and the medium protein
groups also exhibited upregulation in the immune response parameter reared under biofloc irrespective of the
species. SOD activity of the hemocytes were influenced by different dietary protein levels and better inhibition
was observed in HP when compared to control and other treated groups. Thus the native non-SPF Indian white
shrimp P. indicus has comparable potential as the SPF Pacific white shrimp P. vannamei in terms of innate
immunity, immune response, and growth when reared under biofloc conditions.Not Availabl
Not Available
Not AvailableEffect of bio-augmentation of Bacillus spp in biofloc on growth, survival and immunity in Indian white shrimp Penaeus indicus was evaluated. Nine Bacillus strains were isolated and screened individually as well as in the form of a consortia. To maintain a C:N ratio of 12:1 a blend of carbohydrate sources was used. Bio-augmentation with bacterial consortium and Virgibacillus sp. produced improved growth and immunity. Shrimp survival ranged from 80 to 95% among treatments. Production was higher (35%) in the biofloc tanks with an average body weight (ABW) of 10.89 ± 1.2 g. On evaluating the immune responses, it was found that trypsin significantly (P < 0.05) enhanced Prophenoloxidase (PO) activity in Lysinibacillus, Bacillus cereus, Bacillus licheniformis and Bacillus subtilis bio-augmented groups. Laminarin induced PO activity was observed in groups supplemented with Oceanobacillus sp., Bacillus sp.and Bacillus megaterium. The lysozyme (LZ) activity was significantly (P < 0.05) higher in B. cereus and Microbial Consortia (MC), while other treatments were less effective. Total hemocyte count (THC) significantly (P < 0.05) increased in all treatment groups compared to the control. Hyaline hemocyte (HH) count was significantly (P < 0.05) higher in the control group (14.43%). Semi granular hemocytes (SGH) was higher in groups treated with Lysinibacillus, Bacillus sp., B. licheniformis and B. subtilis. The granular hemocyte (GH) count was significantly (P < 0.05) higher in Virgibacillus sp., B. cereus, B.megaterium and Oceanobacillus sp. The biofloc alone (BF), treated and augmented with B. megaterium significantly (P < 0.05) increased phagocytic activity. Highly significant phagocytic index (PI) was observed in bio-augmented groups, BF and MC. The relative expression levels of immune genes were found to be significantly up-regulated in shrimps grown in bio-augmented groups. Enhanced immunological parameters implies that bio-augmentation of biofloc with Bacillus spp. improved immunity in shrimps. Hence, bio-augmentation of probiotics in biofloc may be useful in improving culture conditions to produce P. indicus.Not Availabl