2,332 research outputs found
Estimation of the methane emission factor for the Italian Mediterranean buffalo
In order to contribute to the improvement of the national greenhouse gas emission inventory, this work aimed at estimating a country-specific enteric methane (CH4) emission factor for the Italian Mediterranean buffalo. For this purpose, national agriculture statistics, and information on animal production and farming conditions were analysed, and the emission factor was estimated using the Tier 2 model of the Intergovernmental Panel on Climate Change. Country-specific CH4 emission factors for buffalo cows (630 kg body weight, BW) and other buffalo (313 kg BW) categories were estimated for the period 1990–2004. In 2004, the estimated enteric CH4 emission factor for the buffalo cows was 73 kg/head per year, whereas that for other buffalo categories it was 56 kg/head per year. Research in order to determine specific CH4 conversion rates at the predominant production system is suggested
Reducing Interconnect Cost in NoC through Serialized Asynchronous Links
This work investigates the application of serialization as a means of reducing the number of wires in NoC combined with asynchronous links in order to simplify the clocking of the link. Throughput is reduced but savings in routing area and reduction in power could make this attractiv
Shear viscosity of neutron matter from realistic nucleon-nucleon interactions
The calculation of transport properties of Fermi liquids, based on the
formalism developed by Abrikosov and Khalatnikov, requires the knowledge of the
probability of collisions between quasiparticles in the vicinity of the Fermi
surface. We have carried out a numerical study of the shear viscosity of pure
neutron matter, whose value plays a pivotal role in determining the stability
of rotating neutron stars, in which these processes are described using a
state-of-the-art nucleon-nucleon potential model. Within our approach medium
modifications of the scattering cross section are consistently taken into
account, through an effective interaction obtained from the matrix elements of
the bare interaction between correlated states. Inclusion of medium effects
lead to a large increase of the viscosity at densities larger than
fm^{-3}.Comment: 4 pages, 4 figures. Corrected typo
Clonal Chromosome Anomalies Affecting Fli1 Mimic Inherited Thrombocytopenia Of The Paris-Trousseau Type
Introduction: The thrombocytopenia of the Paris-Trousseau (TCPT) type is a contiguous gene syndrome characterized by mild bleeding tendency, variable thrombocytopenia (THC), abnormal giant alpha-granules in platelets and dysmegakaryopoiesis: it derives from a constitutional deletion of chromosome 11 leading to the loss of FLI1, a transcription factor involved in megakaryocyte differentiation and maturation. Case report: A women with an acquired, isolated THC developing over 10 yr showed morphological features typical of TCPT in platelets and bone marrow (BM). Twenty years after the onset of THC, the other hematological parameters are still normal and the patient is well. Results: Clonal hemopoiesis was shown and chromosome analyses performed on BM revealed a clone with 45 chromosomes and a complex unbalanced translocation involving chromosomes 2, 3, and 11. The anomaly was present in the majority of bone marrow cells but only in a few peripheral blood elements. A microarray-based comparative genomic hybridization defined the deleted region of chromosome 11 including the FLI1 locus that was missing. Conclusion: Although our patient presented with nearly all the characteristics of TCPT, her illness was acquired instead of being inherited and the most appropriate diagnosis is that of the unilineage dysplasia 'refractory THC.' This observation suggests that appropriate cytogenetic investigations should be always considered in patients with acquired THC of unknown origin
OBJECTIVE AND SUBJECTIVE KNOWLEDGE: IMPACTS ON CONSUMER DEMAND FOR GENETICALLY MODIFIED FOODS IN THE UNITED STATES AND THE EUROPEAN UNION
In the growing body of literature on consumer acceptance of genetically modified (GM) foods, there are significant differences on the impact of knowledge on acceptance of GM foods. One potential explanation is the manner in which knowledge is measured. The goal of this study is to differentiate and examine the impact of both subjective and objective knowledge related to acceptance of genetically modified foods. Data from surveys collected in the United States, England, and France is used.Research and Development/Tech Change/Emerging Technologies,
Canopy uptake dominates nighttime carbonyl sulfide fluxes in a boreal forest
Nighttime vegetative uptake of carbonyl sulfide (COS) can exist due to the incomplete closure of stomata and the light independence of the enzyme carbonic anhydrase, which complicates the use of COS as a tracer for gross primary productivity (GPP). In this study we derived nighttime COS fluxes in a boreal forest (the SMEAR II station in Hyytiälä, Finland; 61°51′ N, 24°17′ E; 181 m a.s.l.) from June to November 2015 using two different methods: eddy-covariance (EC) measurements (FCOS-EC) and the radon-tracer method (FCOS-Rn). The total nighttime COS fluxes averaged over the whole measurement period were −6.8 ± 2.2 and −7.9 ± 3.8 pmol m−2 s−1 for FCOS-Rn and FCOS-EC, respectively, which is 33–38 % of the average daytime fluxes and 21 % of the total daily COS uptake. The correlation of 222Rn (of which the source is the soil) with COS (average R2 = 0.58) was lower than with CO2 (0.70), suggesting that the main sink of COS is not located at the ground. These observations are supported by soil chamber measurements that show that soil contributes to only 34–40 % of the total nighttime COS uptake. We found a decrease in COS uptake with decreasing nighttime stomatal conductance and increasing vapor-pressure deficit and air temperature, driven by stomatal closure in response to a warm and dry period in August. We also discuss the effect that canopy layer mixing can have on the radon-tracer method and the sensitivity of (FCOS-EC) to atmospheric turbulence. Our results suggest that the nighttime uptake of COS is mainly driven by the tree foliage and is significant in a boreal forest, such that it needs to be taken into account when using COS as a tracer for GPP
Thyroid status modulates T lymphoma growth via cell cycle regulatory proteins and angiogenesis
We have shown in vitro that thyroid hormones (THs) regulate the balance between proliferation and apoptosis of T lymphoma cells. The effects of THs on tumor development have been studied, but the results are still controversial. Herein, we show the modulatory action of thyroid status on the in vivo growth of T lymphoma cells. For this purpose, euthyroid, hypothyroid, and hyperthyroid mice received inoculations of EL4 cells to allow the development of solid tumors. Tumors in the hyperthyroid animals exhibited a higher growth rate, as evidenced by the early appearance of palpable solid tumors and the increased tumor volume. These results are consistent with the rate of cell division determined by staining tumor cells with carboxyfluorescein succinimidyl ester. Additionally, hyperthyroid mice exhibited reduced survival. Hypothyroid mice did not differ significantly from the euthyroid controls with respect to these parameters. Additionally, only tumors from hyperthyroid animals had increased expression levels of proliferating cell nuclear antigen and active caspase 3. Differential expression of cell cycle regulatory proteins was also observed. The levels of cyclins D1 and D3 were augmented in the tumors of the hyperthyroid animals, whereas the cell cycle inhibitors p16/INK4A (CDKN2A) and p27/Kip1 (CDKN1B) and the tumor suppressor p53 (TRP53) were increased in hypothyroid mice. Intratumoral and peritumoral vasculogenesis was increased only in hyperthyroid mice. Therefore, we propose that the thyroid status modulates the in vivo growth of EL4 T lymphoma through the regulation of cyclin, cyclin-dependent kinase inhibitor, and tumor suppressor gene expression, as well as the stimulation of angiogenesis.Fil: Sterle, Helena Andrea. Pontificia Universidad Católica Argentina ; ArgentinaFil: Valli, Eduardo. Pontificia Universidad Católica Argentina ; ArgentinaFil: Cayrol, Maria Florencia. Pontificia Universidad Católica Argentina ; ArgentinaFil: Paulazo, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Martinel Lamas, Diego José. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Díaz Flaqué, María Celeste. Pontificia Universidad Católica Argentina ; ArgentinaFil: Klecha, Alicia Juana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Colombo, L.. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología ; ArgentinaFil: Medina, Vanina Araceli. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cremaschi, Graciela Alicia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Pontificia Universidad Católica Argentina ; ArgentinaFil: Barreiro Arcos, María Laura. Pontificia Universidad Católica Argentina ; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentin
Radiological evaluation of the metal-bone interface of a porous tantalum acetabular component
Introduction Porous tantalum presents a bone-matched elastic modulus and an high coefficient of friction on cancellous and cortical bone. Furthermore, its open-cell tantalum structure of repeating dodecahedrons, similar to cancellous bone, should be favourable for bone ingrowth. These physical and mechanical properties should increase primary fixation and potential osteointegration of acetabular cups and should decrease periacetabular stress shielding. The purpose of this study was to radiographically evaluate the evolution of the metal-bone interface of porous tantalum acetabular components.
Materials and Methods Serial radiographic evaluation of 41porous tantalum acetabular component has been performed in 40 patients. Twelve hips underwent total hip arthroplasty using a trabecular metal monoblock acetabular component and 29 hips using a trabecular metal modular acetabular system. All patients were clinically and radiographically evaluated at four, eight, 12, 24 weeks, 12 months and then annually. All cases were available for a minimum follow-up of two years (mean 35 months). On post-operative x-rays the metal-bone interface was investigated for areas in which the porous surface of the acetabular component was not in contact with bone. These gaps were measured and classified by
location according to DeLee and Charnley zones. Evolution of postoperative gaps, presence of lysis or periacetabular radiolucencies and component migration were assessed during follow-up.
Results On post-operative x-rays 36 components (88%) had a gap between the outer surface and the host bone but only in 12 cases (29%) gaps were larger then 1 mm. The gaps were mostly situated in the polar region (zone II) when compared with the peripheral zones and no one was bigger then 5 mm in width. At last follow-up 23 (64%) of the initial gaps were no longer radiographically evident, 10 (28%) had a favourable evolution and appeared reduced in dimension but still present and 3 (8%) didn\u2019t fill at all and were unchanged when compared with post-operative controls. There was no progression progression of any post-operative gap and no evidence of new periacetabular radiolucent lines or lysis. No acetabular implant showed evidence of migration or needed revision for loosening. At last follow up the mean Harris Hip Score was 95. There were no dislocation or other complications. Discussion Short term results with porous tantalum acetabular component are encouraging: the bridging of the interface gaps and the absence of periacetabular radiolucencies indicate good mechanical and osteoconductive properties. Further follow-up will be required to confirm these results in the long term
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Pro-arrhythmic atrial phenotypes in incrementally paced murine Pgc1β-/- hearts: effects of age.
What is the central question of this study? Can we experimentally replicate atrial pro-arrhythmic phenotypes associated with important chronic clinical conditions, including physical inactivity, obesity, diabetes mellitus and metabolic syndrome, compromising mitochondrial function, and clarify their electrophysiological basis? What is the main finding and its importance? Electrocardiographic and intracellular cardiomyocyte recording at progressively incremented pacing rates demonstrated age-dependent atrial arrhythmic phenotypes in Langendorff-perfused murine Pgc1β-/- hearts for the first time. We attributed these to compromised action potential conduction and excitation wavefronts, whilst excluding alterations in recovery properties or temporal electrophysiological instabilities, clarifying these pro-arrhythmic changes in chronic metabolic disease. Atrial arrhythmias, most commonly manifesting as atrial fibrillation, represent a major clinical problem. The incidence of atrial fibrillation increases with both age and conditions associated with energetic dysfunction. Atrial arrhythmic phenotypes were compared in young (12-16 week) and aged (>52 week) wild-type (WT) and peroxisome proliferative activated receptor, gamma, coactivator 1 beta (Ppargc1b)-deficient (Pgc1β-/- ) Langendorff-perfused hearts, previously used to model mitochondrial energetic disorder. Electrophysiological explorations were performed using simultaneous whole-heart ECG and intracellular atrial action potential (AP) recordings. Two stimulation protocols were used: an S1S2 protocol, which imposed extrasystolic stimuli at successively decremented intervals following regular pulse trains; and a regular pacing protocol at successively incremented frequencies. Aged Pgc1β-/- hearts showed greater atrial arrhythmogenicity, presenting as atrial tachycardia and ectopic activity. Maximal rates of AP depolarization (dV/dtmax ) were reduced in Pgc1β-/- hearts. Action potential latencies were increased by the Pgc1β-/- genotype, with an added interactive effect of age. In contrast, AP durations to 90% recovery (APD90 ) were shorter in Pgc1β-/- hearts despite similar atrial effective recovery periods amongst the different groups. These findings accompanied paradoxical decreases in the incidence and duration of alternans in the aged and Pgc1β-/- hearts. Limiting slopes of restitution curves of APD90 against diastolic interval were correspondingly reduced interactively by Pgc1β-/- genotype and age. In contrast, reduced AP wavelengths were associated with Pgc1β-/- genotype, both independently and interacting with age, through the basic cycle lengths explored, with the aged Pgc1β-/- hearts showing the shortest wavelengths. These findings thus implicate AP wavelength in possible mechanisms for the atrial arrhythmic changes reported here
Different loss of material in recurrent chromosome 20 interstitial deletions in Shwachman-Diamond syndrome and in myeloid neoplasms
Abstract
BACKGROUND:
An interstitial deletion of the long arms of chromosome 20, del(20)(q), is frequent in the bone marrow (BM) of patients with myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), and myeloproliferative neoplasms (MPN), and it is recurrent in the BM of patients with Shwachman-Diamond syndrome (SDS), who have a 30-40% risk of developing MDS and AML.
RESULTS:
We report the results obtained by microarray-based comparative genomic hybridization (a-CGH) in six patients with SDS, and we compare the loss of chromosome 20 material with one patient with MDS, and with data on 92 informative patients with MDS/AML/MPN and del(20)(q) collected from the literature.
CONCLUSIONS:
The chromosome material lost in MDS/AML/MPN is highly variable with no identifiable common deleted regions, whereas in SDS the loss is more uniform: in 3/6 patients it was almost identical, and the breakpoints that we defined are probably common to most patients from the literature. In some SDS patients less material may be lost, due to different distal breakpoints, but the proximal breakpoint is in the same region, always leading to the loss of the EIF6 gene, an event which was related to a lower risk of MDS/AML in comparison with other patients
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