4,190 research outputs found
Determination of lipid requirements in black soldier fly through semi-purified diets
The insect market is still far from an effective upscale and, to achieve this goal, it is necessary to know the BSF dietary requirements for the production maximization. Worldwide, given the waste variability, is not always easy to identify the optimal waste-based mixture that can allow to reach the best production, in terms of quantity and quality. Due this reason, nutritional need ranges are the basic knowledge, affordable for everyone, to increase the profitability of the insect farming. The study aims to evaluate the effects of 6 semi-purified, isonitrogenous and isoenergetic diets (SPII) with increasing lipid levels (1%, L1; 1.5%, L1.5; 2.5%, L2.5; 3.5% L3.5; 4.5%, L4.5) on BSF life history traits (6 replicates/treatment and 100 larvae/replicate). The Gainesville diet was used as environmental control. Considering the whole larval stage, 4.5% lipid level guarantees better performance when compared to content lower than 2.5%. The L4.5 10-day-old larvae yielded greater when compared to the other dietary treatments. At 14 and 18 days of age, the larvae of the groups above 2.5% performed better than L1, while the L1.5 showed intermediate results. Lipid levels below 1.5% on DM, when compared to 4.5%, resulted in a smaller prepupa and pupa size. The results obtained on the adult stage do not allow the identification of a lipid levels ideal range, as in the larval stage. In conclusion, in the whole larval stage and in prepupae/pupae phases, lipid percentage lower than (or equal to) 1% have a negative effect on growth. Other research will be needed in order to evaluate lipid levels above 4.5% on DM
Development of a robust HS-SPME-GC-MS method for the analysis of solid food samples. Analysis of volatile compounds in fresh raw beef of differing lipid oxidation degrees
This work presents a headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) method for the analysis of solid food samples in extended experiments. The final procedure was used to quantify 30 volatile compounds in fresh beef. The strategy adds robustness to the classic SPME methods for solid samples, by including a control solution that solves several challenges. The control solution contained one representative compound for each studied family of beef, and two internal standards. Response factors were calculated for each family, and were subsequently applied to every compound belonging to the same family. This strategy allowed control of the quantification procedure even when the fibre, column or control solution changed. Repeatability and reproducibility had relative standard deviation values below 17%, except for phenylacetaldehyde, (E)-2-nonenal and (E, Z)-2, 4-decadienal. Although the method described here was applied to animal products, it has also been successfully used to distinguish between samples from different lipid oxidation stabilities
New constraints on supersymmetry using neutrino telescopes
We demonstrate that megaton-mass neutrino telescopes are able to observe the signal from long-lived particles beyond the Standard Model, in particular the stau, the supersymmetric partner of the tau lepton. Its signature is an excess of charged particle tracks with horizontal arrival directions and energy deposits between 0.1 and 1 TeV inside the detector. We exploit this previously-overlooked signature to search for stau particles in the publicly available IceCube data. The data shows no evidence of physics beyond the Standard Model. We derive a new lower limit on the stau mass of 320 GeV (95% C.L.) and estimate that this new approach, when applied to the full data set available to the IceCube collaboration, will reach word-leading sensitivity to the stau mass (m_{\tilde{t}}
= 450GeV)
On the classification of flaring states of blazar
The time evolution of the electromagnetic emission from blazars, in
particular high frequency peaked sources (HBLs), displays irregular activity
not yet understood. In this work we report a methodology capable of
characterizing the time behavior of these variable objects. The Maximum
Likelihood Blocks (MLBs) is a model-independent estimator which sub-divides the
light curve into time blocks, whose length and amplitude are compatible with
states of constant emission rate of the observed source. The MLBs yields the
statistical significance in the rate variations and strongly suppresses the
noise fluctuations in the light curves. We apply the MLBs for the first time on
the long term X-ray light curves (RXTE/ASM) of Mkn~421,Mkn~501, 1ES 1959+650
and 1ES 2155-304, which consist of more than 10 years of observational data
(1996-2007). Using the MLBs interpretation of RXTE/ASM data, the integrated
time flux distribution is determined for each single source considered. We
identify in these distributions the characteristic level as well as the flaring
states of the blazars. All the distributions show a significant component at
negative flux values, most probably caused by an uncertainty in the background
subtraction and by intrinsic fluctuations of RXTE/ASM. This effect interests in
particular short time observations. In order to quantify the probability that
the intrinsic fluctuations give rise to a false identification of a flare, we
study a population of very faint sources and their integrated time flux
distribution. We determine duty cycle or fraction of time a source spent in the
flaring state of the source Mkn~421, Mkn~501, 1ES 1959+650 and 1ES 2155-304.
Moreover, we study the random coincidences between flares and generic sporadic
events such as high energy neutrinos or flares in other wavelengths.Comment: Accepted to A&
HEP Applications Evaluation of the EDG Testbed and Middleware
Workpackage 8 of the European Datagrid project was formed in January 2001
with representatives from the four LHC experiments, and with experiment
independent people from five of the six main EDG partners. In September 2002
WP8 was strengthened by the addition of effort from BaBar and D0. The original
mandate of WP8 was, following the definition of short- and long-term
requirements, to port experiment software to the EDG middleware and testbed
environment. A major additional activity has been testing the basic
functionality and performance of this environment. This paper reviews
experiences and evaluations in the areas of job submission, data management,
mass storage handling, information systems and monitoring. It also comments on
the problems of remote debugging, the portability of code, and scaling problems
with increasing numbers of jobs, sites and nodes. Reference is made to the
pioneeering work of Atlas and CMS in integrating the use of the EDG Testbed
into their data challenges. A forward look is made to essential software
developments within EDG and to the necessary cooperation between EDG and LCG
for the LCG prototype due in mid 2003.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics
Conference (CHEP03), La Jolla, CA, USA, March 2003, 7 pages. PSN THCT00
Progress in unveiling extreme particle acceleration in persistent astrophysical jets
International audienceExtreme blazars emitting teraelectronvolt photons are ideal targets to study particle acceleration processes. The growing number of such sources has been critical for γ-ray cosmology, studying intergalactic magnetic fields and putting constraints on exotic physics
Differentiating Breast Myopathies through Color and Texture Analyses in Broiler
Wooden breast (WB), white striping (WS) and spaghetti meat (SM) are breast myopathies of the Pectoralis major that greatly affect meat quality in broilers. To differentiate color and texture characteristics with instrumental methods, some of them applied for the first time in this species, 300 carcasses were randomly chosen from an abattoir from five different flocks from the same farm, at a rate of 60 carcasses from each flock. Twenty-four hours after slaughter, both side breasts were dissected, and yields calculated. Color was measured on the surface of the breast with a spectrocolorimeter and reflectance values obtained. Texture was measured on raw meat with a modified compression test that hinders the fiber from expanding transversally and a texture profile analysis (TPA) and also on cooked meat with a Warner-Bratzler shear and a TPA. Color differs between severity degrees, increasing redness (from -1.77 to -1.32 in WB) and, especially, yellowness (from 5.00 to 6.73 in WS) and chroma (from 5.75 to 7.22 in SM) with the severity of the myopathy. The subtraction R630 minus R580 was found to be a useful index to differentiate breast myopathies degrees. The modified compression test can be considered an effective tool to assess the hardness of different structures in each myopathy. Texture differences in the myopathies are better assessed in raw than in cooked meat
- …