Motor mechanisms of balance during quiet standing.

The purpose of this paper is to highlight the motor mechanisms involved in balance as the human, as a biped, continuously defends against gravitational and internal forces to maintain a safe posture. The search for these mechanisms needs precise and valid 3D measurements including both limbs plus valid biomechanical models. The literature shows the need for two force platforms to separate the mechanisms at the ankle and hip (load/unload mechanism). Also, precise measures ( approximately 0.03 mm) of markers on a multi-segment 3D bilateral model are required to record the minute trajectories of all segments and joints. The controlled variable, center-of-mass, is seen to be virtually in phase with the controlling variable, the center-of-pressure, which suggests a 0th order system where a simple series elastic spring could maintain balance. The first model involves a mass/spring/damper of medial/lateral balance: the stiffness was varied with stance width and the predicted sway from a spring controlled inverted pendulum closely matched the experimentally measured stiffness and sway. The second was a non-linear model of the plantarflexor series elastic elements which resulted in three closely validated predictions of anterior/posterior balance: the locus of the gravitational load line, the predicted ankle moment and the ankle stiffness at the operating point.     

Isolation of alkaliphilic calcifying bacteria and their feasibility for enhanced CaCO3 precipitation in bio-based cementitious composites

Microbially induced calcite precipitation (MICP), secreted through biological metabolic activity, secured an imperative position in remedial measures within the construction industry subsequent to ecological, environmental and economical returns. However, this contemporary recurrent healing system is susceptible to microbial depletion in the highly alkaline cementitious environment. Therefore, researchers are probing for alkali resistant calcifying microbes. In the present study, alkaliphilic microbes were isolated from different soil sources and screened for probable CaCO₃ precipitation. Non-ureolytic pathway (oxidation of organic carbon) was adopted for calcite precipitation to eliminate the production of toxic ammonia. For this purpose, calcium lactate Ca(C₃H₅O₃)₂ and calcium acetate Ca(CH₃COO)₂ were used as CaCO₃ precipitation precursors. The quantification protocol for precipitated CaCO₃ was established to select potent microbial species for implementation in the alkaline cementitious systems as more than 50% of isolates were able to precipitate CaCO₃. Results suggested 80% of potent calcifying strains isolated in this study, portrayed higher calcite precipitation at pH 10 when compared to pH 7. Ten superlative morphologically distinct isolates capable of CaCO₃ production were identified by 16SrRNA sequencing. Sequenced microbes were identified as species of Bacillus, Arthrobacter, Planococcus, Chryseomicrobium and Corynebacterium. Further, microstructure of precipitated CaCO₃ was inspected through scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermal gravimetric (TG) analysis. Then, the selected microbes were investigated in the cementitious mortar to rule out any detrimental effects on mechanical properties. These strains showed maximum of 36% increase in compressive strength and 96% increase in flexural strength. Bacillus, Arthrobacter, Corynebacterium and Planococcus genera have been reported as CaCO₃ producers but isolated strains have not yet been investigated in conjunction with cementitious mortar. Moreover, species of Chryseomicrobium and Glutamicibacter were reported first time as calcifying strains.     

Infliximab substantially re-silenced Wnt/β-catenin signaling and ameliorated doxorubicin-induced cardiomyopathy in rats

The release of inflammatory cytokines, namely tumor necrosis factor-α (TNF-α), plays an important role in the pathogenesis of cardiomyopathy. TNF-α increases in plasma and in myocardium of heart failure patients. We aimed to investigate the role of TNF-α inhibitor (infliximab; IFX) in regulating dilated cardiomyopathy (DCM) induced in rats. DCM was induced in rats by doxorubicin (DOX; 3.5 mg. kg⁻¹, i.p) twice weekly for 3 weeks (21 mg. kg⁻¹ cumulative dose). DCM rats were treated with RPL (1 mg. kg⁻¹ orally, daily), IFX (5 mg. kg⁻¹; i.p. once) or their combination for 4 weeks starting next day of last DOX dose. Echocardiography was conducted followed by a collection of blood and left ventricle (LV) for biochemical and histological investigations. DCM rats revealed deteriorated cardiac function (increased CK-MB activity, LVIDs, LVIDd, ESV, and EDV, while decreased EF% and FS%), hypertrophy (increased HW/TL, β-MHC, and α-actin), inflammation (increased IL-1β, IL-6, and TNF-α). The activation of Wnt/β-catenin along with increased gene expression of RAS components (RENIN, ACE, and AT1) were evident. LV architecture also revealed abnormalities and some degree of fibrosis. Treatment with RPL and/or IFX suppressed TNF-α and consequently improved most of these parameters suppressing Wnt/β-catenin/RAS axis. Combined RPL and IFX treatment was the best among all treatments. In conclusion, Wnt/β-catenin/RAS axis is implicated in DOX-induced cardiomyopathy. The upstream TNF-α was proved for the first time in-vivo to stimulate this axis where its inhibition by RPL or IFX prevented DCM. Targeting this axis at two points using RPL and IFX showed better therapeutic efficacy.     

Triacontanol-mediated regulation of growth and other physiological attributes,active constituents and yield of <Emphasis Type="Italic">Mentha arvensis</Emphasis> L.

Triacontanol (TRIA) has been realized as a potent plant growth promoting substance for a number of agricultural and horticultural crops. Out of a large number of essential oil bearing plants, mint (Mentha arvensis L.) constitutes the most important source of therapeutic agents used in the alternative systems of medicine. The mint plant has marvelous medicinal properties. In view of enhancing growth, yield and quality of this medicinally important plant, a pot experiment was conducted according to simple randomized block design. The experiment was aimed at studying the effect of four concentrations of TRIA (10⁻⁰, 10⁻⁷, 10⁻⁶ and 10⁻⁵ M) on the performance of mint with regard to growth and other physiological attributes, crop yield and quality attributes and the yield and contents of active constituents of the plant. The growth and other physiological parameters as well as yield and quality attributes were studied at 100 and 120 DAP. The foliar application of TRIA at 10⁻⁶ M concentration significantly enhanced most of the growth and other physiological attributes, crop herbage yield and the yield and content of active constituents (menthol, l-methone, isomenthone and menthyl acetate) of mint at both the stages. However, the next higher concentration of TRIA (10⁻⁵ M) exhibited slightly negative effect and did not further increase the values of the attributes studied, but it proved significantly better than the control. Application of TRIA significantly enhanced the yield and content of all the active constituents determined by GLC technique.     

Redox and mTOR-dependent regulation of plasma lamellar calcium influx controls the senescence-associated secretory phenotype

Cellular senescence has evolved as a protective mechanism to arrest growth of cells with oncogenic potential but is accompanied by the often pathologically deleterious senescence-associated secretory phenotype (SASP). Here we demonstrate an H₂O₂-dependent functional disruption controlling senescence-associated Ca²⁺ homeostasis and the SASP. Senescent cells fail to respond to H₂O₂-dependent plasma lamellar Ca²⁺ entry when compared to pre-senescent cells. Limiting exposure to senescence-associated H₂O₂ restores H₂O₂-dependent Ca²⁺ entry as well as transient receptor potential cation channel subfamily C member 6 (TRPC6) function. SA-TRPC6 and SASP expression is blocked by restoring Ca²⁺ entry with the TRP channel antagonist SKF-96365 or by the mTOR inhibitors rapamycin and Ku0063794. Together, our findings provide compelling evidence that redox and mTOR-mediated regulation of Ca²⁺ entry through TRPC6 modulates SASP gene expression and approaches which preserve normal Ca²⁺ homeostasis may prove useful in disrupting SASP activity.Impact statementThrough its ability to evoke responses from cells in a paracrine fashion, the senescence-associated secretory phenotype (SASP) has been linked to numerous age-associated disease pathologies including tumor invasion, cardiovascular dysfunction, neuroinflammation, osteoarthritis, and renal disease. Strategies which limit the amplitude and duration of SASP serve to delay age-related degenerative decline. Here we demonstrate that the SASP regulation is linked to shifts in intracellular Ca²⁺ homeostasis and strategies which rescue redox-dependent calcium entry including enzymatic H₂O₂ scavenging, TRP modulation, or mTOR inhibition block SASP and TRPC6 gene expression. As Ca²⁺ is indispensable for secretion from both secretory and non-secretory cells, it is exciting to speculate that the expression of plasma lamellar TRP channels critical for the maintenance of intracellular Ca²⁺ homeostasis may be coordinately regulated with the SASP.     

Amelioration of salinity tolerance in <Emphasis Type="Italic">Solanum tuberosum</Emphasis> L. by exogenous application of ascorbic acid

The present investigation envisaged revealing the role of exogenous application of ascorbic acid in increasing resistance against NaCl stress. Shoot apices from 60-d-old, in vitro-grown plants of two commercially important cultivars of Solanum tuberosum L., cvs. Desiree and Cardinal, were inoculated on Murashige and Skoog (MS) medium supplemented with 0.5 mM ascorbic acid for 72 h as a pretreatment. Pretreated and non-pretreated shoot apices were transferred to MS medium containing different concentrations of NaCl (0–140 mM; eight treatments). Results were recorded for morphological (shoot length, shoot number, root length, root number, and number of nodes) and biochemical features (protein, peroxidase, catalase, and superoxide dismutase activities) after 60 d of salt treatment. Similarly, 60-d-old, well-proliferated callus cultures were also pretreated with ascorbic acid for 24 h and transferred to an optimized callus proliferation medium containing different concentrations of salt. Results were recorded after 60 d of salt treatment for percentage relative fresh weight growth and biochemical parameters. Salinity severely inhibited all the growth parameters in both the cultivars. Pretreatment with ascorbic acid to both salt-treated plants and callus cultures showed significant differences with respect to almost all of the growth and biochemical parameters studied. Protein content as well as catalase and superoxide dismutase activities increased significantly in both the cultivars, although peroxidase activity showed a decreasing trend in ascorbic acid-pretreated plants as well as callus cultures.     

Large scale production and characterisations of dihydrofolate reductase from a methotrexate-resistant human lymphoid cell line

Dihydrofolate reductase has been purified from a methotrexate-resistant human lymphoid cell line (CCRF/CEM-R3) and up to 1 mg of enzyme has been obtained from 5 litres of culture. The enzyme has a molecular weight of 22000 ±500 as determined by gel filtration. The pH activity profile shows a single optimum at pH 7.7, where marked activation is observed by addition of 0.2 M NaCl. TheK _m for NADPH is 3μM and dihydrofolate 0.7μM. The binding constant for the inhibitor, methotrexate, is 29 pM     

A semiautomated 96-well plate assay for protein kinase C

We have devised a rapid procedure for the assay of protein kinase C. Reactions (100 microliters) were set up in the wells of a 96-well assay plate and initiated one column at a time by the addition of [gamma-32P]ATP with an eight-channel pipettor. After incubation for 5 min at 30 degrees C, the reactions were terminated by the addition of 100 microliters of 25% trichloroacetic acid. The reaction mixtures were then filtered using a semiautomatic cell harvester, and transferred to scintillation vials using a filter punch apparatus. Direct comparison of this method to traditional techniques revealed a three- to fivefold increase in efficiency with equal sensitivity. This method is suitable for screening large numbers of inhibitors and activators of protein kinase C and appears to be applicable to other enzymes such as calmodulin kinases.     

Effect of plant age and turfgrass competition on the efficacy of the Sclerotinia minor granular bioherbicide on broadleaf plantain and prostrate knotweed

Broadleaf plantain and prostrate knotweed are important weeds of turfgrass systems. The fungus Sclerotinia minor Jagger (IMI 344141) has been registered as a biological herbicide (Sarritor?) for dandelion (Taraxacum officinale) in Canadian turfgrass habitats. The objective of this study was to evaluate the effect of plant age and turfgrass environment on the efficacy of S. minor against two additional weeds; broadleaf plantain and prostrate knotweed. The turfgrass environment alone exerted significant reduction of above and below ground biomass of broadleaf plantain, to the same magnitude as the S. minor treatment in a grass-free environment. Prostrate knotweed biomass, however, was not reduced to this extent by competition with turfgrass. In the presence of grass, S. minor caused a significant biocontrol effect on all studied variables with more than 90% above ground damage on both weed species. Severe damage occurred on 3–6-week-old plantains with 100% above and below ground reduction, although smaller dry weight reductions were observed on older plantains. Treatment with S. minor reduced the dry matter of 3–5-week-old prostrate knotweed by 65–85%, but less damage occurred on older prostrate knotweed. The bioherbicide fungus is destructive for both species, but variation in area of contact due to different growth forms, growth rates and resource allocation patterns due to different life forms resulted in different biocontrol efficacy on the two species. Control of broadleaf plantain was effective – similar to that previously reported for dandelion – but control of prostrate knotweed was only partial.