Combinations of antioxidants and/or of epigenetic enzyme inhibitors allow for enhanced collection of mouse bone marrow hematopoietic stem cells in ambient air

Hematopoietic cell transplantation (HCT) is a treatment for malignant and non-malignant disorders. However, sometimes the numbers of donor hematopoietic stem cells (HSC) are limiting, which can compromise the success of HCT. We recently published that collection and processing of mouse bone marrow (BM) and human cord blood cells in a hypoxic atmosphere of 3% O2 or in ambient air (~21% O2) in the presence of cyclosporine A yields increased numbers of HSC. We now show that collection and processing of mouse BM cells in ambient air in the presence of specific combinations of anti-oxidants and/or inhibitors of epigenetic enzymes can also enhance the collection of HSC, information of potential relevance for enhanced efficacy of HCT

Free-riding Analysis Via Dynamic Game with Incomplete Information

AbstractP2P networks are distributed, acentric and self-organized systems. Due to the incomplete information of network environment, the uncertainty of trust relationship among peers and the selfishness of the peers in P2P networks, which give rise to many free-riders that seriously impact the stability and scalability of P2P networks. In this paper, by analyzing the incomplete information of network environment, the uncertainty of trust relationship among nodes, the phenomenon of the free-riding is studied based on game theory. The IIDGTrust (Incomplete Information Dynamic Game Trust)mechanism is presented through the case “Supplying the Public Resources”. Updating the trust relationship among the nodes according to the Bayesian law, which make nodes choose better strategies in time. The experimental results demonstrate that the IIDGTrust mechanism can effectively reduce the proportion of the free-riders in the P2P networks and maintain the stability of networks better

Particulate Organic Carbon Export Fluxes in The Canada Basin and Bering Sea as Derived from 234Th/238U Disequilibria

Seawater samples were collected in the water column of the Canada Basin and the Bering Sea from aboard the R/V Xue Long during August 1999. Activity concentrations of dissolved and particulate 234Th were measured using beta counting techniques to quantify the scavenging and residence time of 234Th and organic carbon export fluxes. Primary production (PP) and bacterial production were also determined in the study areas through in situ incubation experiments. Significant 234Th scavenging was observed in the upper 100 m of the water column in both study areas, with up to 40% of 234Th deficit found at Bering Sea stations and ~15% of 234Th deficit at the Canada Basin station. Measured PP decreased from ~12.5 µmol C/m³/h in surface water to near zero at ~100 m depth, with an integrated PP of 3.83 mmol C/m²/d in the Canada Basin. Bacterial production, on the other hand, was on the order of 2.0 mmol C/m²/d, which is up to 52% of the integrated PP. Particulate organic carbon (POC) export fluxes derived from 234Th/238U disequilibrium were ~1 mmol C/m²/d in the Canada Basin and ~10 mmol C/m²/d in the Bering Sea, with fluxes in the latter area being 5 to 10 times higher than those found in the Canada Basin. These export fluxes correspond to a ThE ratio (the ratio of 234Th-derived POC export to primary production) of 0.26 for the Canada Basin and 0.7 for the Bering Sea. The higher ThE ratios in the study areas suggest a decoupling of production and particulate export in the high-latitude ocean. Ratios of POC to particulate 234Th (µmol C/dpm) decreased consistently with increasing depth, suggesting that organic carbon is preferentially remineralized relative to 234Th. Interestingly, the profile of particulate 234Th in the Canada Basin showed a unique characteristic: particulate 234Th activities increased with increasing depth, suggesting a continuous scavenging of 234Th and a rapid settling rate of the particles.Au cours du mois d'août 1999, on a prélevé des échantillons d'eau de mer dans la colonne d'eau du bassin Canada et de la mer de Béring depuis le vaisseau RV Xue-Long. L'activité volumique du 234Th dissous et particulaire a été mesurée à l'aide de techniques de comptage au rayonnement bêta afin de quantifier le temps de balayage et le temps de séjour du 234Th et les flux d'exportation du carbone organique. On a aussi établi la production primaire (PP) et la production bactérienne dans les zones d'étude en réalisant des expériences d'incubation in situ. Dans les deux zones d'étude, on a observé un balayage marqué du 234Th dans les 100 m supérieurs de la colonne d'eau, avec jusqu'à 40 p. cent de déficit de 234Th aux postes de la mer de Béring et environ 15 p. cent au poste du bassin Canada. La PP mesurée baissait d'environ 12,5 µmol C/m³/h dans l'eau de surface à près de zéro à environ 100 m de profondeur, avec une PP intégrée de 3,83 mmol C/m²/j dans le bassin Canada. D'autre part, la production bactérienne était de l'ordre de 2,0 mmol C/m²/j, ce qui représente jusqu'à 52 p. cent de la PP intégrée. Les flux d'exportation du carbone organique particulaire (COP) calculés à partir du déséquilibre 234Th /238U étaient d'environ 1 mmol C/m²/j dans le bassin Canada et d'environ 10 mmol C/m²/j dans la mer de Béring, les flux dans cette région étant de 5 à 10 fois plus élevés que ceux trouvés dans le bassin Canada. Ces flux d'exportation correspondent à un rapport ThE (le rapport de l'exportation du COP dérivé du 234Th à la production primaire) de 0,26 pour le bassin Canada et de 0,7 pour la mer de Béring. Les rapports plus élevés de ThE dans les zones d'étude suggèrent un découplage de la production et de l'exportation de particules dans l'océan septentrional. Les rapports de COP au 234Th particulaire (µmol C/dpm) diminuaient de façon uniforme avec l'augmentation de la profondeur, ce qui suggère que le carbone organique est reminéralisé préférentiellement par rapport au 234Th. Il est à noter que le profil du 234Th particulaire dans le bassin Canada affichait une caractéristique unique: l'activité du 234Th particulaire augmentait avec la profondeur, ce qui suggère un balayage continu du 234Th et un taux rapide de sédimentation des particules

Holographic Algorithms Beyond Matchgates

Holographic algorithms introduced by Valiant are composed of two ingredients: matchgates, which are gadgets realizing local constraint functions by weighted planar perfect matchings, and holographic reductions, which show equivalences among problems with different descriptions via certain basis transformations. In this paper, we replace matchgates in the paradigm above by the affine type and the product type constraint functions, which are known to be tractable in general (not necessarily planar) graphs. More specifically, we present polynomial-time algorithms to decide if a given counting problem has a holographic reduction to another problem defined by the affine or product-type functions. Our algorithms also find a holographic transformation when one exists. We further present polynomial-time algorithms of the same decision and search problems for symmetric functions, where the complexity is measured in terms of the (exponentially more) succinct representations. The algorithm for the symmetric case also shows that the recent dichotomy theorem for Holant problems with symmetric constraints is efficiently decidable. Our proof techniques are mainly algebraic, e.g., using stabilizers and orbits of group actions.Comment: Inf. Comput., to appear. Author accepted manuscrip

Thermodynamic Properties of Spherically-Symmetric, Uniformly-Accelerated Reference Frames

We aim to study the thermodynamic properties of the spherically symmetric reference frames with uniform acceleration, including the spherically symmetric generalization of Rindler reference frame and the new kind of uniformly accelerated reference frame. We find that, unlike the general studies about the horizon thermodynamics, one cannot obtain the laws of thermodynamics for their horizons in the usual approaches, despite that one can formally define an area entropy (Bekenstein-Hawking entropy). In fact, the common horizon for a set of uniformly accelerated observers is not always exist, even though the Hawking-Unruh temperature is still well-defined. This result indicates that the Hawking-Unruh temperature is only a kinematic effect, to gain the laws of thermodynamics for the horizon, one needs the help of dynamics. Our result is in accordance with those from the various studies about the acoustic black holes.Comment: 8 page