9,176 research outputs found
Aristelliger praesignis (Jamaican Croaking Lizard). Maximum Size.
This article is available as on open access publication downloadable from the Society for the Study of Amphibians and Reptiles website https://ssarherps.org/herpetological-review-pdfs/. The attached file is the published pdf
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Mesoporous CaCO3 crystals as novel vectors for in ovo delivery
The continuing increase in population demands for an a
ordable food and protein source, farmed poultry provides a means to combat this. Current growth rates within modern broiler lines have continually increased due to intense genetic selection; due to this, the developing embryo cannot solely rely on the contents of the egg for its successful growth. In ovo feeding (IOF) is the nutrient supplementation of the egg and acts to improve the energy-status of late-term chick embryos. Current methodologies to provide IOF are based upon mechanical injection, which can result in the reduced structural integrity of the eggshell and leaves the developing embryo susceptible to bacterial infection. Moreover, delivered nutrients are unprotected, and there is a lack of protective delivery vectors.
The permeation of food-grade carrier gels is proposed as an alternative approach to IOF via injection. An investigation into the surface properties of the eggshell is presented, focusing on shell permeability and porosity. This permeation is dependent upon the polarity of the carrier gel. With this, an injection-free delivery method is proposed utilising the spontaneous permeation of polypropylene glycol (PPG) through the eggshell. IOF is demonstrated through the delivery of fluorescently labelled model bioactives. Delivery vectors dispersed throughout the PPG carrier gel act as hosts and an approach to protect sensitive bioactive material.
Both vaterite CaCO3 crystals and their layer-by-layer templated microgels are novel inorganic and organic structures which have attracted significant scientific interest as drug delivery vectors owing to their biological relevance, low-cost production, and highly tuneable properties. This work seeks to develop delivery vectors based on vaterite crystals and biopolymer microgels for non-invasive IOF, and to aid in the delivery of micro- and nano-encapsulated nutrients or other compounds of interest.
Vaterite crystals (diameter of 0.5-20 m) can be loaded with model nutrients such as food-grade macromolecular dextrans and small molecule cobalamin (vitamin B12) via co-synthesis, reaching up to 8 and 1% w/w, respectively. Neutral dextran (DEX) and its charged derivatives (carboxymethyl- (CM) and diethylaminoethyl (DEAE)-DEX) were utilised. The molecular weight and charge of DEX does not a
ect the crystal size, but drastically influence the crystal porosity. Neutral and CM-DEX can stabilise vaterite against the recrystallisation to non-porous calcite. Vitamin B12 does not affect the vaterite morphology.
The formulation of sixteen types of vaterite-templated biopolymer-based microgels is investigated utilising four polycations (poly-L-lysine (PLL), protamine (PR), dextran amine (DA) and collagen (COL)) and four polyanions (hyaluronic acid (HA), chondroitin sulfate (CS), dextran sulfate (DS) and heparin sulfate (HS)). Stable microgels are formed from all polyanions paired with PLL and PR, whereas those paired with DA and COL undergo dissolution or disaggregation. Formation of the microgels has been correlated with the stability of the respective polyelectrolyte complexes at increased ionic strength. All formed microgels shrink upon template dissolution and the degree of shrinkage increased in the series of polyanions HS < DS < CS < HA. The same trend is observed for the adhesion of microgels to the surface upon which they are formed. The biopolymer molecular weight and charge also governs the microgel stability and internal structure. Neutral and charged DEX, as well as silver nanoparticles (AgNPs) can be encapsulated into microgels via pre-loading (co-synthesis with vaterite templates) or post-loading (adsorption to formed microgels). The loading mechanism is governed by the mechanical entrapment of cargo, as well as electrostatic interactions, where the components of charge and the capping agent of AgNPs play a role.
The findings of this thesis open new routes for the design of, and encapsulation within, CaCO3-based vectors. Such vectors may aid in the preservation of activity, protection, and the controlled release of necessary bioactive compounds for chick development. The novel permeation-based IOF approach demonstrates the universal delivery of bioactive compounds - both free and encapsulated - and its potential to replace IOF via injection
Parton Distributions for Event Generators
In this paper, conventional Global QCD analysis is generalized to produce
parton distributions optimized for use with event generators at the LHC. This
optimization is accomplished by combining the constraints due to existing
hard-scattering experimental data with those from anticipated cross sections
for key representative SM processes at LHC (by the best available theory) as
joint input to the global analyses. The PDFs obtained in these new type of
global analyses using matrix elements calculated in any given order will be
best suited to work with event generators of that order, for predictions at the
LHC. This is most useful for LO event generators at present. Results obtained
from a few candidate PDF sets (labeled as CT09MCS, CT09MC1 and CT09MC2) for LO
event generators produced in this way are compared with those from other
approaches.Comment: 35 pages, 19 figures, and 4 table
Modelling ricochet of a cylinder on water using ALE and SPH methods
The ricochet means the rebound off a surface and is a very important scenario in engineering applications. The specific case of an impact of a solid steel body on a water surface has been chosen for the ricochet example. This solid body hits the water surface with a certain velocity and angle and their dependency on the ricochet behaviour is of interest. This impact scenario can be further developed for more complex impact scenarios, like the ditching of aeroplanes, and has been extensively studied in the past. Due to that fact, it was decided to compare the two numerical analyses with each other; SPH in the internal developed code MCM at Cranfield University with the ALE method in the commercial programme LS-Dyna. The early state of the development was the reason that a 2D model was developed in the 3D solver and therefore verification with another method crucial. Therefore the two simulations were set up and the ricochet behaviour investigated. In contrast to the experimental results, these results demonstrate that independent of the numerical method, both models show an unexpected overproduction of ricochet at higher impact velocities, but agree in their over prediction. The benefits arising out of the collaborative approach of SPH and ALE to describe a problem are presented
Physical aspects of oracles for randomness, and Hadamard's conjecture
We analyze the physical aspects and origins of currently proposed oracles for
(absolute) randomness.Comment: 10 pages, 3 figures. arXiv admin note: substantial text overlap with
arXiv:1405.140
Numerical modelling of the effect of using multi-explosives on the explosive forming of steel cones
Modelling and analysis of underwater explosive forming process by using FEM and SPH formulation is presented in this work. The explosive forming of a steel cone is studied. The model setup includes a low carbon steel plate, plate holder, forming die as well as water and C4 explosive. The effect of multiple explosives on rate of targets deformation has been studied. Four different multi-explosives models have been developed and compared to the single explosive model. The formability of the steel plate based on forming limit failure criteria has been investigated. Aspects such as shape of plates deformation and thickness of the plate during the forming process have been examined. The model results indicate that a multi-explosives model does not always guarantee a faster rate of target deformation without central explosive. On the other hand the model results indicate that the multi-explosives setup is capable of preventing crack failure of the steel plate during the forming process which would occur if a single explosive model was used
Identifying Treatment Effect Modifiers in the STarT Back Trial: A Secondary Analysis
Identification of patient characteristics influencing treatment outcomes is a top low back pain (LBP) research priority. Results from the STarT Back Trial support the effectiveness of prognostic stratified care for LBP compared to current best care, however patient characteristics associated with treatment response have not yet been explored. The purpose of this secondary analysis was to identify treatment-effect modifiers within the STarT Back Trial at 4 months follow-up (n=688). Treatment response was dichotomized using back-specific physical disability measured by the Roland-Morris Disability Questionnaire (≥7). Candidate modifiers were identified using previous literature and evaluated using logistic regression with statistical interaction terms to provide preliminary evidence of treatment-effect modification. Socioeconomic status (SES) was identified as an effect modifier for disability outcomes (OR = 1.71, P=.028). High SES patients receiving prognostic stratified care were 2.5 times less likely to have a poor outcome compared to low SES patients receiving best current care (OR = 0.40, P=.006). Education level (OR = 1.33, P=.109) and number of pain medications (OR = 0.64, P=.140) met our criteria for effect modification with weaker evidence (0.20>P≥0.05). These findings provide preliminary evidence for SES, education, and number of pain medications as treatment-effect modifiers of prognostic stratified care delivered in the STarT Back Trial
A study of the effect of projectile orientation on the results of ballistic impact tests as described in the EASA CS-25 regulations for fuel tank access covers
This paper presents the results of an investigation of the ballistic limits and failure modes of AA2024-T351 sheets impacted with cubical projectiles. The experiment/test setup was based on EASA CS-25 regulations for fuel tank access covers. The effect of cube orientation on the ballistic limit and failure modes was considered in detail. A 25% variation in ballistic limit was observed with the lowest ballistic limit (202 m/s) observed for the cubical projectile edge impacted on the target. In the cube face impacts, the ballistic limit was higher (223 m/s), and the highest ballistic limit (254 m/s) was observed for the corner impact. The observed differences in the ballistic limit were due to differences in failure mechanism, which resulted in different localised deformations near the projectile impact point, but also led to differences in global dishing deformation
b-Initiated processes at the LHC: a reappraisal
Several key processes at the LHC in the standard model and beyond that
involve quarks, such as single-top, Higgs, and weak vector boson associated
production, can be described in QCD either in a 4-flavor or 5-flavor scheme. In
the former, quarks appear only in the final state and are typically
considered massive. In 5-flavor schemes, calculations include quarks in the
initial state, are simpler and allow the resummation of possibly large initial
state logarithms of the type into the
parton distribution function (PDF), being the typical scale of the
hard process. In this work we critically reconsider the rationale for using
5-flavor improved schemes at the LHC. Our motivation stems from the observation
that the effects of initial state logs are rarely very large in hadron
collisions: 4-flavor computations are pertubatively well behaved and a
substantial agreement between predictions in the two schemes is found. We
identify two distinct reasons that explain this behaviour, i.e., the
resummation of the initial state logarithms into the -PDF is relevant only
at large Bjorken and the possibly large ratios 's are
always accompanied by universal phase space suppression factors. Our study
paves the way to using both schemes for the same process so to exploit their
complementary advantages for different observables, such as employing a
5-flavor scheme to accurately predict the total cross section at NNLO and the
corresponding 4-flavor computation at NLO for fully exclusive studies.Comment: Fixed typo in Eq. (A.10) and few typos in Eq. (C.2) and (C.3
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