Obesity negatively impacts aerobic capacity improvements both acutely and 1-year following cardiac rehabilitation

Cardiac rehabilitation (CR) produces a host of health benefits related to modifiable cardiovascular risk factors. The purpose of the present investigation was to determine the influence of body weight, assessed through BMI, on acute and long-term improvements in aerobic capacity following completion of CR. Three thousand nine hundred and ninety seven subjects with coronary artery disease (CAD) participated in a 12-week multidisciplinary CR program. Subjects underwent an exercise test to determine peak estimated metabolic equivalents (eMETs) and BMI assessment at baseline, immediately following CR completion and at 1-year follow-up. Normal weight subjects at 1-year follow-up demonstrated the greatest improvement in aerobic fitness and best retention of those gains (gain in peak METs: 0.95 ± 1.1, P < 0.001). Although the improvement was significant (P < 0.001), subjects who were initially classified as obese had the lowest aerobic capacity and poorest retention in CR fitness gains at 1-year follow-up (gain in peak eMETs: 0.69 ± 1.2). Subjects initially classified as overweight by BMI had a peak eMET improvement that was also significantly better (P < 0.05) than obese subjects at 1-year follow-up (gain in peak eMETs: 0.82 ± 1.1). Significant fitness gains, one of the primary beneficial outcomes of CR, can be obtained by all subjects irrespective of BMI classification. However, obese patients have poorer baseline fitness and are more likely to "give back" fitness gains in the long term. Obese CAD patients may therefore benefit from additional interventions to enhance the positive adaptations facilitated by CR.     

The influence of light on microtubule dynamics and alignment in the Arabidopsis hypocotyl

Light and dark have antagonistic effects on shoot elongation, but little is known about how these effects are translated into changes of shape. Here we provide genetic evidence that the light/gibberellin-signaling pathway affects the properties of microtubules required to reorient growth. To follow microtubule dynamics for hours without triggering photomorphogenic inhibition of growth, we used Arabidopsis thaliana light mutants in the gibberellic acid/DELLA pathway. Particle velocimetry was used to map the mass movement of microtubule plus ends, providing new insight into the way that microtubules switch between orthogonal axes upon the onset of growth. Longitudinal microtubules are known to signal growth cessation, but we observed that cells also self-organize a strikingly bipolarized longitudinal array before bursts of growth. This gives way to a radial microtubule star that, far from being a random array, seems to be a key transitional step to the transverse array, forecasting the faster elongation that follows. Computational modeling provides mechanistic insight into these transitions. In the faster-growing mutants, the microtubules were found to have faster polymerization rates and to undergo faster reorientations. This suggests a mechanism in which the light-signaling pathway modifies the dynamics of microtubules and their ability to switch between orthogonal axes.     

Factors affecting micropropagation and acclimatization of an elite clone of Eucalyptus tereticornis Sm.

Several factors influencing micropropagation of a selected elite clone of Eucalyptus tereticornis Sm. were investigated. Amongst different cytokinins tested, 6-benzyleadenine proved to be the most effective cytokinin for shoot multiplication and elongation. The initial size of the shoot clump (inoculum) also influenced shoot multiplication and elongation. The number of shoots proliferated per culture vessel were significantly higher (342 shoots per culture vessel) when larger shoot clumps (15?C20 shoots) were inoculated, compared to smaller shoot clumps (4?C5 shoots), which resulted in a reduced shoot proliferation rates (245 shoots per culture vessel). However, the number of elongated shoots (65 per culture vessel) and shoot length (5.23?cm) were higher in cultures which were inoculated with smaller shoot clumps in comparison to those cultures which were inoculated with larger shoot clumps (54 shoots per culture vessel with shoot length of 4.17?cm). The maximum number of rooted shoots (80.7?%) was obtained on one fourth-strength MS medium supplemented with 5.0???M indolebutyric acid. The number of shoots proliferated, elongated, rooting frequency, and subsequent survival of plants after acclimatization were higher in cultures incubated under photosynthetically active radiation (PAR) compared to those incubated under cool fluorescent lights (CFL). Osmotic potential of the sap and chlorophyll content of cultures incubated under PAR were also higher than those incubated under CFL. Following transfer of plants to soil, inoculation with a suspension of Bacillus subtilis (plant growth-promoting bacterium) increased the survival rate of plants by 10?%, yielding successful transfer of 84?% of plants. Random amplified polymorphic DNA and inter simple sequence repeat analyses indicated a high level of clonal uniformity amongst regenerated plants and also with that of the mother plant.     

A novel role for aquaporin-5 in enhancing microtubule organization and stability

Aquaporin-5 (AQP5) is a water-specific channel located on the apical surface of airway epithelial cells. In addition to regulating transcellular water permeability, AQP5 can regulate paracellular permeability, though the mechanisms by which this occurs have not been determined. Microtubules also regulate paracellular permeability. Here, we report that AQP5 promotes microtubule assembly and helps maintain the assembled microtubule steady state levels with slower turnover dynamics in cells. Specifically, reduced levels of AQP5 correlated with lower levels of assembled microtubules and decreased paracellular permeability. In contrast, overexpression of AQP5 increased assembly of microtubules, with evidence of increased MT stability, and promoted the formation of long straight microtubules in the apical domain of the epithelial cells. These findings indicate that AQP5-mediated regulation of microtubule dynamics modulates airway epithelial barrier properties and epithelial function.     

Ubiquitin removal in the TGF-β pathway

The transforming growth factor (TGF-β) pathway is regulated by ubiquitin-mediated proteolysis at different levels. Two studies now identify deubiquitinating enzymes (DUBs) for the TGF-β type I receptor. Both ubiquitin-specific peptidase-4 (USP4) and -15 (USP15) extend the life of activated receptors against the negative pressure of receptor-ubiquitinating complexes, but through distinct modes of action.     

Characterization and Pathogenic Relationships of Rhizoctonia solani Isolates in a Potato–Rice System and their Sensitivity to Fungicides

Potato is planted after rice in several parts of Punjab in India and both crops are attacked by Rhizoctonia solani Kühn. Potato tubers showing black scurf and rice plants affected by sheath blight were collected from different regions of the state and the isolates of R. solani so obtained were studied to determine their variability and to ascertain their cross-infectivity and response to fungicides. Potato isolates of R. solani did not infect rice plants but some rice isolates were weakly pathogenic on potato, the sclerotia being less firmly attached on tuber surface, indicating a possible unsuccessful attempt of rice isolates to infect potato. Rice isolates (66.6%) grew faster (>20 mm colony growth per 24 h) than those of the potato isolates (15–20 mm growth rate per 24 h). Hyphal width of isolates from both hosts varied from 7.2 to 12.1 μm. Colony growth of most potato isolates (61.2%) was appressed, whereas that of most rice isolates (53.3%) was fluffy. Rice isolates (73.3%) formed larger sclerotia (1.5–2.0 mm in diameter) than those of the potato isolates (0.5–1.0 mm in diameter). Anastomosis studies indicated that potato isolates belonged to AG-3 and AG-5 groups while rice isolates belonged to the AG-1-1-A group. Representative R. solani isolates from the two hosts showed significant variation in response to fungicides (i.e. carbendazim, carboxin, pencycuron, propiconazole and validamycin) based on their ED₅₀ and ED₉₀ values.     

Synthesis and cytotoxic activity of heterocyclic ring-substituted betulinic acid derivatives

A new series of betulinic acid derivatives have been synthesized by introducing heterocyclic ring between C-2 and C-3 positions of betulinic acid. Further modifications were also carried out by reduction of C-20(29) unsaturated bond and substitution of C-28 carboxyl group by ester and amide linkage to enhance the selectivity. Compound 11 resulted in IC(50) of 2.44, 2.5, and 2.7 microg/ml on MIAPaCa, PA-1, and SW620 cancer cell lines, respectively. Compound 38 resulted in IC(50) of 0.67 microg/ml on MIAPaCa cell line.     

Place prioritization for biodiversity conservation using probabilistic surrogate distribution data

We analyse optimal and heuristic place prioritization algorithms for biodiversity conservation area network design which can use probabilistic data on the distribution of surrogates for biodiversity. We show how an Expected Surrogate Set Covering Problem (ESSCP) and a Maximal Expected Surrogate Covering Problem (MESCP) can be linearized for computationally efficient solution. For the ESSCP, we study the performance of two optimization software packages (XPRESS and CPLEX) and five heuristic algorithms based on traditional measures of complementarity and rarity as well as the Shannon and Simpson indices of α‐diversity which are being used in this context for the first time. On small artificial data sets the optimal place prioritization algorithms often produced more economical solutions than the heuristic algorithms, though not always ones guaranteed to be optimal. However, with large data sets, the optimal algorithms often required long computation times and produced no better results than heuristic ones. Thus there is generally little reason to prefer optimal to heuristic algorithms with probabilistic data sets.