A rapid screening method for estimation of total fermentable value of selected plant materials.

Plant material is heated at 105°C in trifluoroacetic acid. After neutralisation and dilution, the reducing substances in this solution are determined by an automated colorimetric procedure, using 3,5 dinitrosalicylic acid. The resulting figure, described in this paper as the total fermentable value is used as an estimate of certain carbohydrate substances, for example starch and sugars in the sample. The method is manipulatively simple, and is suitable for screening of large batches of plant samples. The precision for a single determination is ±2.7%

Evaluation of selected extractants for boron in some Queensland soils

Glasshouse and laboratory studies were undertaken to evaluate a range of extractants for determining the boron status of a suite of predominantly acidic soils. In addition to hot water (commonly used as an extractant for soil boron), hot 0.01 M CaCl2,, 0.05 M mannitol/0.01 M CaCl2, 0.05 M mannitol (buffered at pH 7.9, 1 M NH4OAc, 5% (v/v) glycerol and 0.01 M tartaric acid were assessed as extractants since these reagents can complex boron. Sunflower (Helianthus annuus cv. Hysun 31) was grown with three levels of applied boron (0, 0.5 and 1.0 kg B ha-1) in each of 20 soils. Relative dry matter yield, tissue boron concentration, boron uptake and relative boron uptake of control plants (0 kg B ha- l) were determined. Both hot water and hot 0.01 M CaCl2 extractable boron were related to each of these plant parameters, whereas boron extracted by the other procedures was not. Levels of boron extracted with mannitol and glycerol were very low in comparison to those displaced from the soil by the refluxing procedures. The inability of mannitol to extract boron from these soils is discussed in relation to the chemistry of mannitol-boron complexes, and it is suggested that mannitol would not be an effective extractant for boron in acid soils. Soil solution extracts (obtained after equilibration at 10 kPa matric suction) had concentrations < 0.1 µg B ml-l. Because of the low concentrations and narrow range across the 20 soils, soil solution boron was not related to plant growth parameters obtained from the glasshouse study

Compensation of elevation angle variations in polarimetric brightness temperature measurements from airborne microwave radiometers

This paper presents a method for compensating the elevation angle fluctuations occurring in airborne radiometry due to aircraft roll and pitch. The correction is based on a radiative transfer model, and is demonstrated by real data from conical scans over the ocean, showing good results.Peer Reviewe

Haematopoietic stem cells require a highly regulated protein synthesis rate

Many aspects of cellular physiology remain unstudied in somatic stem cells. For example, there are almost no data on protein synthesis in any somatic stem cell. We found that the amount of protein synthesized per hour in haematopoietic stem cells (HSCs) in vivo was lower than in most other haematopoietic cells, even if we controlled for differences in cell cycle status or forced HSCs to undergo self-renewing divisions. Reduced ribosome function in Rpl24Bst/+ mice further reduced protein synthesis in HSCs and impaired HSC function. Pten deletion increased protein synthesis in HSCs but also reduced HSC function. Rpl24Bst/+ cell-autonomously rescued the effects of Pten deletion in HSCs, blocking the increase in protein synthesis, restoring HSC function, and delaying leukaemogenesis. Pten deficiency thus depletes HSCs and promotes leukaemia partly by increasing protein synthesis. Either increased or decreased protein synthesis impairs HSC function

On Board Accurate Calibration of Dual-Channel Radiometers Using Internal and External References

This paper presents a method for combining internal noise injection and external reference standard looks to accurately calibrate an airborne dual-channel radiometer. The method allows real-time estimation of the correct values of the radiometer gains and offsets, even for nontemperature-stabilized radiometers and with minimum loss of measurement time spent in external load measurement. Crosstalk and leakage introduced by the noise injection circuitry is also taken into account, thus providing high gain and offset estimation accuracy. The method was implemented on a National Oceanic and Atmospheric Administration airborne instrument, the Polarimetric Scanning Radiometer, which was used to obtain an extensive set of radiometric measurements over oceanic convection during CAMEX3 in August–September 1998

Influence of Hydrodynamic Interactions on the Adsorption Process of Large Particles

We have studied the adsorption process of non-Brownian particles on a line incorporating hydrodynamic interactionsa and we have numerically analyzed their effect on typical relevant quantities. We compare our model to the ballistic deposition model (BM) and address the limitations of BM in experimental situations. The results obtained can explain some differences observed between recent experiments and BM predictions.Comment: 10 pages, LaTeX. 4 Figures upon reques

Pten cell autonomously modulates the hematopoietic stem cell response to inflammatory cytokines

Summary: Pten negatively regulates the phosphatidylinositol 3-kinase (PI3K) pathway and is required to maintain quiescent adult hematopoietic stem cells (HSCs). Pten has been proposed to regulate HSCs cell autonomously and non-cell autonomously, but the relative importance of each mechanism has not been directly tested. Furthermore, the cytokines that activate the PI3K pathway upstream of Pten are not well defined. We sought to clarify whether Pten cell autonomously or non-cell autonomously regulates HSC mobilization. We also tested whether Pten deficiency affects the HSC response to granulocyte colony-stimulating factor (G-CSF) and interferon-α (IFNα) since these cytokines induce HSC mobilization or proliferation, respectively. We show that Pten regulates HSC mobilization and expansion in the spleen primarily via cell-autonomous mechanisms. Pten-deficient HSCs do not require G-CSF to mobilize, although they are hyper-sensitized to even low doses of exogenous G-CSF. Pten-deficient HSCs are similarly sensitized to IFNα. Pten therefore modulates the HSC response to inflammatory cytokines. : Magee and colleagues show that Pten suppresses HSC mobilization and extramedullary expansion primarily through cell-autonomous mechanisms. The authors also show that Pten-deficient HSCs are hyper-sensitive to mobilizing effects of G-CSF and interferon-α, even at low-cytokine concentrations. These findings suggest that a key function of Pten in HSCs is to blunt signal transduction downstream of inflammatory cytokines

An interleukin 6-based genetic risk score strengthened with interleukin 10 polymorphisms associated with long-term kidney allograft outcomes

Of all kidney transplants, half are still lost in the first decade after transplantation. Here, using genetics, we probed whether interleukin 6 (IL-6) could be a target in kidney transplantation to improve graft survival. Additionally, we investigated if a genetic risk score (GRS) based on IL6 and IL10 variants could improve prognostication of graft loss. In a prospective cohort study, DNA of 1271 donor-recipient kidney transplant pairs was analyzed for the presence of IL6, IL6R, IL10, IL10RA, and IL10RB variants. These polymorphisms and their GRS were then associated with 15-year death-censored allograft survival. The C|C-genotype of the IL6 polymorphism in donor kidneys and the combined C|C-genotype in donor-recipient pairs were both associated with a reduced risk of graft loss (p =.043 and p =.042, respectively). Additionally, the GRS based on IL6, IL6R, IL10, IL10RA, and IL10RB variants was independently associated with the risk of graft loss (HR 1.53, 95%-CI [1.32–1.84]; p &lt;.001). Notably, the GRS improved risk stratification and prediction of graft loss beyond the level of contemporary clinical markers. Our findings reveal the merits of a polygenic IL-6-based risk score strengthened with IL-10- polymorphisms for the prognostication and risk stratification of late graft failure in kidney transplantation.</p

Depressed mood predicts pulmonary rehabilitation completion among women, but not men

SummaryBackgroundAs many as 30% of patients who start pulmonary rehabilitation (PR) fail to complete it, and depressed mood has been associated with PR non-completion. Depression is more common in women than men with COPD and historically women with COPD have been under studied. However, no studies to date have investigated gender-specific predictors of PR completion.MethodsThe study included 111 patients with COPD who enrolled in a community based outpatient PR program in Providence, RI. Patients who attended 20 or more sessions were designated “completers”. Depression was measured using the CES-D. Logistic regression models were evaluated to test depressed mood as a predictor of PR completion. Analyses controlled for demographic and health variables found to differ between completers and non-completers.ResultsPatients were 95% white and 49.5% women, and 74% had a GOLD stage ≥3. Sixty-eight percent of patients were PR completers. A logistic regression model, showed that lower depressed mood independently predicted PR completion across all patients (adjusted OR = 0.92, p = .002). In gender-stratified analyses, lower depressed mood was an independent predictor of PR completion for women (adjusted OR = .91, p = .024) but not men (adjusted OR = .97, p = .45). Greater 6-min walk test distance was also an independent predictor of PR completion among women.ConclusionDepressed mood is an important predictor of completion of community based PR among women. Screening and brief treatment of depression should be considered in practice