79 research outputs found

    Effects of sodium nitrite treatment on the fermentation quality of red clover-grass silage harvested at two dry matter concentrations and inoculated with clostridia

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    Legumes are particularly susceptible to clostridial fermentation when ensiled because of their high buffering capacity and water-soluble carbohydrate contents. The aim of the study was to investigate if a sodium nitrite treatment (900 g t(-1) herbage in fresh matter [FM]) impairs butyric acid fermentation of red clover-timothy-meadow fescue silage compared with formic acid-treated (4 l t(-1) FM) and untreated silage. The sward was harvested after wilting at low dry matter (DM) (LDM, 194 g kg(-1)) and high DM (HDM, 314 g kg(-1)) concentrations and half of the herbage batches were inoculated with Clostridium tyrobutyricum spores before additive treatments. No butyric acid fermentation was observed in HDM silages probably because of the relatively high DM and nitrate contents of the herbage mixture. In LDM silage butyric acid was detected only in formic acid-treated silage, and the number of clostridia copies was higher in formic acid-treated than in sodium nitrite treated silage. Sodium nitrite treatment was superior to FA treatment in suppressing clostridial fermentation in the LDM silages.Peer reviewe

    Impact of hexamine addition to a nitrite-based additive on fermentation quality, Clostridia and Saccharomyces cerevisiae in a white lupin-wheat silage

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    BACKGROUND Nitrite and hexamine are used as silage additives because of their adverse effects on Clostridia and Clostridia spores. The effect of sodium nitrite and sodium nitrite/hexamine mixtures on silage quality was investigated. A white lupin-wheat mixture was treated with sodium nitrite (NaHe0) (900 g t(-1) forage), or mixtures of sodium nitrite (900 g t(-1)) and hexamine. The application rate of hexamine was 300 g t(-1) (NaHe300) or 600 g t(-1) (NaHe600). Additional treatments were the untreated control (Con), and formic acid (FA) applied at a rate of 4 L t(-1) (1000 g kg(-1)). RESULTS Additives improved silage quality noticeably only by reducing silage ammonia content compared with the control. The addition of hexamine to a sodium nitrite solution did not improve silage quality compared with the solution containing sodium nitrite alone. The increasing addition of hexamine resulted in linearly rising pH values (P <0.001) and decreasing amounts of lactic acid (P <0.01). Sodium nitrite based additives were more effective than formic acid in preventing butyric acid formation. Additives did not restrict the growth of Saccharomyces cerevisiae compared to the control. CONCLUSION The addition of hexamine did not improve silage quality compared with a solution of sodium nitrite. (c) 2018 Society of Chemical IndustryPeer reviewe

    Herd-Level and Individual Differences in Fecal Lactobacilli Dynamics of Growing Pigs

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    Simple SummarySelection for hyper-prolific sows has led to increased litter size, decreased birth weight, and increased within-litter variation. This is accompanied by impaired colostrum intake of piglets and poor performance. We aimed to investigate the total count of fecal lactobacilli and species diversity in growing pigs on two herds. Study pigs were categorized either small or large according to their birth weight. Sow colostrum quality and colostrum supply of piglets were determined. We hypothesized that the birth weight and growth performance of pigs are associated with fecal lactobacilli composition, which is influenced by colostrum. Small pigs had higher lactobacilli counts in both herds, but the difference was significant only for one herd (p = 0.01). Colostrum quality was numerically better in the herd that appeared also better managed in comparison to the other study herd. Colostrum intake tended to be significantly associated with the total lactobacilli count in the better-managed herd. In conclusion, herd-level factors clearly contribute to the microbiota of pigs, but birth weight also plays a potential role in the gastrointestinal tract lactobacilli dynamics. Our results revealed a potential long-term effect of colostrum, and therefore give a reason to investigate more thoroughly the associations between maternal immunity, pig microbiota, and performance.We studied the fecal lactobacilli count and species diversity of growing pigs along with immune parameters associated with intestinal lactobacilli. Thirty pigs categorized as small (S, n = 12) or large (L, n = 18) at birth were followed from birth to slaughter in two commercial herds, H1 and H2. Herds differed in terms of their general management. We determined sow colostrum quality, colostrum intake, piglet serum immunoglobulins, and pig growth. We took individual fecal samples from pigs in the weaning and finishing units. We studied lactobacilli count and identified their diversity with 16S PCR. Total lactobacilli count increased in H1 and decreased in H2 between samplings. Lactobacilli species diversity was higher in H1 in both fecal sampling points, whereas diversity decreased over time in both herds. We identified altogether seven lactobacilli species with a maximum of five (one to five) species in one herd. However, a relatively large proportion of lactobacilli remained unidentified with the used sequencing technique. Small pigs had higher lactobacilli counts in both herds but the difference was significant only in H2 (p = 0.01). Colostrum quality was numerically better in H1 than in H2, where colostrum intake tended to be associated with total lactobacilli count (p = 0.05)

    Pharmacological inhibition of Carbonic Anhydrase IX and XII to enhance targeting of acute myeloid leukaemia cells under hypoxic conditions

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    Acute myeloid leukaemia (AML) is an aggressive form of blood cancer that carries a dismal prognosis. Several studies suggest that the poor outcome is due to a small fraction of leukaemic cells that elude treatment and survive in specialised, oxygen (O2)‐deprived niches of the bone marrow. Although several AML drug targets such as FLT3, IDH1/2 and CD33 have been established in recent years, survival rates remain unsatisfactory, which indicates that other, yet unrecognized, mechanisms influence the ability of AML cells to escape cell death and to proliferate in hypoxic environments. Our data illustrates that Carbonic Anhydrases IX and XII (CA IX/XII) are critical for leukaemic cell survival in the O2‐deprived milieu. CA IX and XII function as transmembrane proteins that mediate intracellular pH under low O2 conditions. Because maintaining a neutral pH represents a key survival mechanism for tumour cells in O2‐deprived settings, we sought to elucidate the role of dual CA IX/XII inhibition as a novel strategy to eliminate AML cells under hypoxic conditions. Our findings demonstrate that the dual CA IX/XII inhibitor FC531 may prove to be of value as an adjunct to chemotherapy for the treatment of AML.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/171236/1/jcmm17027_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/171236/2/jcmm17027-sup-0001-FigS1-S4.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/171236/3/jcmm17027.pd

    Measurement of (anti)alpha production in central Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 5.02 TeV

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    International audienceIn this letter, measurements of (anti)alpha production in central (0-10%) Pb-Pb collisions at a center-of-mass energy per nucleon-nucleon pair of sNN\sqrt{s_{\rm NN}} = 5.02 TeV are presented, including the first measurement of an antialpha transverse-momentum spectrum. Owing to its large mass, (anti)alpha production yields and transverse-momentum spectra are of particular interest because they provide a stringent test of particle production models. The averaged antialpha and alpha spectrum is included into a common blast-wave fit with lighter particles, indicating that the (anti)alpha also participates in the collective expansion of the medium created in the collision. A blast-wave fit including only protons, (anti)alpha, and other light nuclei results in a similar flow velocity as the fit that includes all particles. A similar flow velocity, but a significantly larger kinetic freeze-out temperature is obtained when only protons and light nuclei are included in the fit. The coalescence parameter B4B_4 is well described by calculations from a statistical hadronization model but significantly underestimated by calculations assuming nucleus formation via coalescence of nucleons. Similarly, the (anti)alpha-to-proton ratio is well described by the statistical hadronization model. On the other hand, coalescence calculations including approaches with different implementations of the (anti)alpha substructure tend to underestimate the data

    Studying the interaction between charm and light-flavor mesons

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    International audienceThe two-particle momentum correlation functions between charm mesons (D±\mathrm{D^{*\pm}} and D±\mathrm{D}^\pm) and charged light-flavor mesons (π±\pi^{\pm} and K±^{\pm}) in all charge-combinations are measured for the first time by the ALICE Collaboration in high-multiplicity proton-proton collisions at a center-of-mass energy of s=13\sqrt{s} =13 TeV. For DK\mathrm{DK} and DK\mathrm{D^*K} pairs, the experimental results are in agreement with theoretical predictions of the residual strong interaction based on quantum chromodynamics calculations on the lattice and chiral effective field theory. In the case of Dπ\mathrm{D}\pi and Dπ\mathrm{D^*}\pi pairs, tension between the calculations including strong interactions and the measurement is observed. For all particle pairs, the data can be adequately described by Coulomb interaction only, indicating a shallow interaction between charm and light-flavor mesons. Finally, the scattering lengths governing the residual strong interaction of the Dπ\mathrm{D}\pi and Dπ\mathrm{D^*}\pi systems are determined by fitting the experimental correlation functions with a model that employs a Gaussian potential. The extracted values are small and compatible with zero

    Common femtoscopic hadron-emission source in pp collisions at the LHC

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    International audienceThe femtoscopic study of pairs of identical pions is particularly suited to investigate the effective source function of particle emission, due to the resulting Bose-Einstein correlation signal. In small collision systems at the LHC, pp in particular, the majority of the pions are produced in resonance decays, which significantly affect the profile and size of the source. In this work, we explicitly model this effect in order to extract the primordial source in pp collisions at s=13\sqrt{s} = 13 TeV from charged π\pi-π\pi correlations measured by ALICE. We demonstrate that the assumption of a Gaussian primordial source is compatible with the data and that the effective source, resulting from modifications due to resonances, is approximately exponential, as found in previous measurements at the LHC. The universality of hadron emission in pp collisions is further investigated by applying the same methodology to characterize the primordial source of K-p pairs. The size of the primordial source is evaluated as a function of the transverse mass (mTm_{\rm T}) of the pairs, leading to the observation of a common scaling for both π\pi-π\pi and K-p, suggesting a collective effect. Further, the present results are compatible with the mTm_{\rm T} scaling of the p-p and pΛ-\Lambda primordial source measured by ALICE in high multiplicity pp collisions, providing compelling evidence for the presence of a common emission source for all hadrons in small collision systems at the LHC. This will allow the determination of the source function for any hadron--hadron pairs with high precision, granting access to the properties of the possible final-state interaction among pairs of less abundantly produced hadrons, such as strange or charmed particles

    Prompt and non-prompt J/ψ/\psi production at midrapidity in Pb-Pb collisions at sNN\sqrt{s_{\mathrm{NN}}} = 5.02 TeV

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    International audienceThe transverse momentum (pTp_{\rm T}) and centrality dependence of the nuclear modification factor RAAR_{\rm AA} of prompt and non-prompt J/ψ/\psi, the latter originating from the weak decays of beauty hadrons, have been measured by the ALICE collaboration in Pb-Pb collisions at sNN\sqrt{s_{\mathrm{NN}}} = 5.02 TeV. The measurements are carried out through the e+e{\rm e}^{+}{\rm e}^{-} decay channel at midrapidity (y|y| 5 GeV/cc, which becomes stronger with increasing collision centrality. The results are consistent with similar LHC measurements in the overlapping pTp_{\rm T} intervals, and cover the kinematic region down to pTp_{\rm T} = 1.5 GeV/cc at midrapidity, not accessible by other LHC experiments. The suppression of prompt J/ψ/\psi in central and semicentral collisions exhibits a decreasing trend towards lower transverse momentum, described within uncertainties by models implementing J/ψ/\psi production from recombination of c and c\overline{\rm c} quarks produced independently in different partonic scatterings. At high transverse momentum, transport models including quarkonium dissociation are able to describe the suppression for prompt J/ψ/\psi. For non-prompt J/ψ/\psi, the suppression predicted by models including both collisional and radiative processes for the computation of the beauty-quark energy loss inside the quark-gluon plasma is consistent with measurements within uncertainties
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