Acceleration Workspace of Cooperating Multi-Finger Robot Systems

We present a mathematical method for acceleration workspace analysis of cooperating multi-finger robot systems using a model of point-contact with friction. A new unified formulation from dynamic equations of cooperating multi-finger robots is derived considering the force and acceleration relationships between the fingers and the object to be handled. From the dynamic equation, maximum translational and rotational acceleration bounds of an object are calculated under given constraints of contact conditions, configurations of fingers, and bounds on the torques of joint actuators for each finger. Here, the rotational acceleration bounds can be applied as an important manipulability index when the multi-finger robot grasps an object. To verify the proposed method, we used a set of case studies with a simple multi-finger mechanism system. The achievable acceleration boundary in task space can be obtained successfully with the proposed method and the acceleration boundary depends on the configurations of fingers.     

卡维地洛对慢性心力衰竭患者神经内分泌及心功能的影响

目的:观察卡维地洛对慢性心力衰竭患者神经内分泌及心功能的影响.方法:60例慢性心力衰竭患者随机分为对照组(n=30)和卡维地洛组(n=30).对照组给予洋地黄、利尿剂、血管紧张素转化酶抑制剂等常规治疗;卡维地洛组在给予常规治疗的基础上加用卡维地洛,从小剂量(3.125mg,1次/天)逐渐加至靶剂量(12.5mg,2次/天或3次/天)治疗6个月.治疗前及治疗6个月后放射免疫法测定血浆血管紧张素Ⅱ(Ang Ⅱ)及内皮素-1(ET-1)水平,超声心动图检测心功能.结果:两组治疗后较治疗前Ang Ⅱ及ET-1水平显著降低,卡维地洛组改善更明显(P＜0.01);两组左房内径、左室舒张末期内径(LVEDD)和左室收缩末期内径(LVESD)明显缩短(P＜0.01),左室射血分数(LVEF)显著增高(P＜0.01).结论:卡维地洛抑制心衰患者的神经内分泌激活,逆转心室重塑,改善心功能.     

Computer-aided design of polyketides with the required properties

An approach to rational design of new polyketides with the required spectrum of biological activity has been proposed. We have developed the BioGenPharm software, which generates combinatorial libraries of polyketides based on the user-defined input parameters, performs prediction of biological activity spectra for the generated structures and selection of molecuels with the required properties. PASS algorithm has been applied for prediction of polyketide activity spectra (http://www.ibmc.msk.ru/PASS). Validation of PASS prediction ability for polyketides was performed vs. the evaluation set containing 242 natural macrolides from the Dictionary of Natural Products. The mean prediction accuracy was 75.5%. The problem of choice of the cutting points for probability of the presence of activity (Pa), which provides optimal combination of such parameters as sensitivity, specificity, concordance has been considered. Applicability of the described method has been illustrated by generation of a virtual library of the erythromycin analogues and selection of substances with low probability of the hepatotoxic effect.     

Localization of aquaporin-2, renal morphology and urine composition in the bottlenose dolphin and the Baird’s beaked whale

This study examined the distribution pattern of aquaporin-2 (AQP2), relative medullary thickness (RMT) and urine properties in the bottlenose dolphin Tursiops truncatus and Baird’s beaked whale Berardius bairdii. Immunohistochemical studies revealed that AQP2 was localized in the collecting tubules/ducts of both species’ renicules, as in terrestrial mammals. The collecting ducts with AQP2 were thinner and arranged more densely in the dolphin than in the whale. RMT values in the renicule were moderate in both species, but were significantly higher in the dolphin (6.0 ± 0.9) than the whale (4.9 ± 0.7). Urine of the bottlenose dolphin is comparatively concentrated (osmolality: 1715.7 ± 279.4 mOsm kg⁻¹, Na⁺: 490.1 ± 87.9 mmol l⁻¹, Cl⁻: 402.7 ± 79.6 mmol l⁻¹, K⁺: 80.7 ± 25.8 mmol l⁻¹, urea nitrogen: 703.5 ± 253.9 mmol l⁻¹), while urine of the dead Baird’s beaked whale is less concentrated (osmolality: 837.5 ± 293.8 mOsm kg⁻¹, Na⁺: 192.9 ± 81.5 mmol l⁻¹, Cl⁻: 159.9 ± 71.4 mmol l⁻¹, K⁺: 44.3 ± 29.5 mmol l⁻¹, urea nitrogen: 270.7 ± 120.3 mmol l⁻¹). These data suggest it is possible that the differences in these renal morphological features may be related in some way to the difference in urine composition between the species, although further studies are necessary. M. Suzuki and N. Endo are equal contributors to this study.     

Seasonal differences in photosynthesis between the C3 and C4 subspecies of Alloteropsis semialata are offset by frost and drought

The regional abundance of C₄ grasses is strongly controlled by temperature, however, the role of precipitation is less clear. Progress in elucidating the direct effects of photosynthetic pathway on these climate relationships is hindered by the significant genetic divergence between major C₃ and C₄ grass lineages. We addressed this problem by examining seasonal climate responses of photosynthesis in Alloteropsis semialata , a unique grass species with both C₃ and C₄ subspecies. Experimental manipulation of rainfall in a common garden in South Africa tested the hypotheses that: (1) photosynthesis is greater in the C₄ than C₃ subspecies under high summer temperatures, but this pattern is reversed at low winter temperatures; and (2) the photosynthetic advantage of C₄ plants is enhanced during drought events. Measurements of leaf gas exchange over 2 years showed a significant photosynthetic advantage for the C₄ subspecies under irrigated conditions from spring through autumn. However, the C₄ leaves were killed by winter frost, while photosynthesis continued in the C₃ plants. Unexpectedly, the C₄ subspecies also lost its photosynthetic advantage during natural drought events, despite greater water-use efficiency under irrigated conditions. This study highlights previously unrecognized roles for climatic extremes in determining the ecological success of C₃ and C₄ grasses.     

Assessment of Minerals in Obesity-related Diseases in the Chandigarh (India) Population

Excessive Zn but normal Cu and Mg in the staple food consumed by the people of Chandigarh (Union territory and capital of Punjab and Haryana States of India) has been considered to be the major risk factor for the prevalence of obesity (33.15%) and obesity-related diseases in this region. Therefore, in the present investigations, in obesity-related diseases, the status of these minerals was estimated in their tissues, including hair, nails, and blood serum and urine, and compared with those of normal subjects. They were grouped as: normal subjects in control Group A, middle-aged diabetics in Group D_M, older diabetics in Group D_O, and diabetics with osteoarthritis in Group D+ OA, osteoarthritis in Group OA and rheumatoid arthritis in Group RA, respectively. The results evaluated in the order as: hair Zn, group D+OA>D_M>OA>A (control)>RA>D_O (p < 0.001); hair Cu, group A (control)>D_M>OA>D+OA>D_O>RA (p < 0.001); hair Mg, group A (control)>D_M>OA>D+OA>RA>D_O (p < 0.001, 0.01); hair Mn, group A (control)>RA>OA>D-OA>D_M>D_O (p < 0.001); nail Zn, group D_M>D+OA>OA>A (control)>RA>D_O (p < 0.001, 0.05); nail Cu, group A (control)>OA>D_M>D+OA>RA>D_O (p < 0.001); nail Mg, group A (control)>OA>D_M>D_O>D+OA >RA (p < 0.001); nail Mn, group A (control) >RA>OA>D+OA>D_M>D_O (p < 0.01); urine Zn, group D_O>D_M>D+OA>A (control)>RA>OA (p < 0.01); urine Cu, group RA>D+OA>D_O>OA> D_M>A (control) (p<0.001); urine Mg, group RA>OA>D+OA>D_O>D_M>A (control; p < 0.001); urine Mn, group D_O>D_M>OA>D+OA>RA>A (control; p < 0.001), respectively. The analysis of the mineral status in serum of diabetics further showed their highly significant rise from lower mean age subgroup to higher mean age subgroup than their control counter parts (p < 0.001, 0.01, and 0.05) with coincident deficiencies of Cu, Mg, and Mn in their tissues. This study would be helpful considering the status of minerals in these obesity-related diseases depending on the choice of the food consumed to improve the quality of life and prognosis for the diseases.     

Kinase-dependent adhesion to fibronectin: regulation by calreticulin

We studied the phosphorylation (activation status) of c-Src and CaMKII in MEFs either wild type for calreticulin, calreticulin-null, or rescued with full-length calreticulin. We found that calreticulin-null cells were poorly spread on the substratum and formed few, if any, focal contacts. Fibronectin expression and deposition were lower in calreticulin-null MEFs compared to calreticulin-expressing cells, which also exhibited increased c-Src and CaMKII phosphorylation (activity). Plating MEFs on preformed fibronectin rescued the poor adhesive phenotype of calreticulin-null cells, and caused a decrease in c-Src Y418 phosphorylation (activity). c-Src inhibition caused the calreticulin-null MEFs to become well spread on the substratum and to make many prominent focal contacts. Calmodulin and CaMKII inhibition caused similar results, along with a notable increase in paxillin phosphorylation (activation). To test if the calcium storage function of calreticulin was responsible for these effects, we manipulated intracellular [Ca(2+)]. Lowering [Ca(2+)](ER) caused an increase in c-Src phosphorylation and a decrease in fibronectin abundance. Conversely, increasing [Ca(2+)] caused opposite effects. These results suggest that calreticulin regulates both the c-Src and calmodulin/CaMKII pathways, enabling cells to be better spread on the substratum by allowing greater fibronectin deposition and increased focal contact formation.     

Calcium-induced tripartite binding of intrinsically disordered calpastatin to its cognate enzyme, calpain

The activity of calpain is controlled by the free intracellular calcium level and by the protein's intrinsically disordered endogenous inhibitor, calpastatin, mediated by short conserved segments: subdomains A-C. The exact binding mode of calpastatin to the enzyme has until now been unclear. Our NMR data of the 141 amino acid long inhibitor, with and without calcium and calpain, have revealed structural changes and a tripartite binding mode, in which the disordered inhibitor wraps around, and contacts, the enzyme at three points, facilitated by flexible linkers. This unprecedented binding mode permits a unique combination of specificity, speed and binding strength in regulation.     

Involvement of Sema4A in the progression of experimental autoimmune myocarditis

Dilated cardiomyopathy often results from autoimmunity triggered by microbial infections during myocarditis. However, it remains unclear how immunological disorders are implicated in pathogenesis of autoimmune myocarditis. Here, we demonstrated that Sema4A, a class IV semaphorin, plays key roles in experimental autoimmune myocarditis (EAM). Dendritic cells pulsed with myosin heavy chain-α peptides induced severe myocarditis in wild-type mice, but not in Sema4A-deficient mice. In adoptive transfer experiments, CD4⁺ T-cells from wild-type mice induced severe myocarditis, while CD4⁺ T-cells from Sema4A-deficient mice exhibited considerably attenuated myocarditis. Our results indicated that Sema4A is critically involved in EAM by regulating differentiation of T-cells.