Susceptibility of silver birch (Betula pendula) to herbivorous insects is associated with the size and phenology of birch – implications for climate warming     

Kaisa Heimonen  Anu Valtonen  Sari Kontunen-Soppela  Sarita Keski-Saari  Matti Rousi  Elina Oksanen 《Scandinavian Journal of Forest Research》2017,32(2):95-104

Susceptibility of trees to herbivorous insects is often associated with the tree growth and phenology, both of which are sensitive to a warming climate. Therefore, changes in these traits may affect the intensity of herbivory on trees in the future. We grew silver birch (Betula pendula) populations differing in their growth and phenology in a common garden experiment, and studied the effect of these plant traits on the leaf herbivory, insect herbivore density and community composition of herbivores in two consecutive years, 2011 and 2012. Differences in size and the timing of growth cessation among the birch genotypes were related to differences in herbivore community compositions and herbivory. In 2011, the most intensive herbivore damage was observed on birch genotypes of small size, late bud burst and early growth cessation, and these genotypes originated from high-latitude populations. The differences among birch genotypes in their susceptibility to herbivore damage may lead to differences in their competitive abilities. While climate warming will affect phenology and growth of plants, our study shows, that it may indirectly affect herbivory and herbivore communities as well.  相似文献   

Influence of Sowing Dates on Yield and Oil Quality in Sunflower     

Sarita  Gupta  Desiraju  Subrahmanyam V. S. Rathore 《Journal of Agronomy and Crop Science》1994,172(2):137-144

Effect of sowing dates (temperature regimes) on growth, yield oil content and quality in sunflower ( Helianthus annuus L. ) was studied. Plants of early sowings which had received low temperature during 0–45 days of growth grew very poorly in height. Plant height significantly correlated with temperature at all the three growth stages. Plants sown in March produced highest yield and January sown plants recorded lowest yield. Protein content of seeds decreased where as the oil content increased with delay in sowing dates. Oil content in the seeds collected from different sowing dates showed significant differences. However, oil content was not significantly correlated with temperatures at any growth stages. Incorporation of ¹⁴C-acetate into lipids of developing seeds was increased as the sowing was delayed. Early sown plants had higher percentage of oleic acid and late sown plants had higher percentage of linoleic acid. Effect sowing dates on oil content and oil quality were discussed on the basis of temperature variation during different growth stages.  相似文献   

Resistance of purebred and crossbred Nigerian Dwarf goats to rinderpest     

G. R. Scott  D. E. Currie  S. Ramachandran  D. H. Hill 《Tropical animal health and production》1970,2(1):13-17

Summary The responses of susceptible purebred and crossbred Nigerian Dwarf goats to caprinized rinderpest virus differed significantly. The factor responsible was probably not innate.

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Resumen La reacción de cabras susceptibles de raza pura y cruzadas al virus caprinizado de “Rinderpest” diferió considerablemente. El factor responsable probablemente no era homologo.

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Résumé Les réponses des chèvres naines de Nigéria de race pure ou de race métisse au virus caprinisé de la peste bovine ont montré des différences significatives. Le facteur responsable de ces variations n'était sans doute pas d'ordre génétique.

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Congenital melanoma in a calf. A review and case report     

C G Sivadas  M K Nair  A Rajan  K M Ramachandran 《The British veterinary journal》1971,127(6):289-293

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Reaction of lung tissue of goats to rinderpest caprinized virus     

S Ramachandran  M R Dhanda 《The Indian veterinary journal》1968,45(1):1-7

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Worldwide human relationships inferred from genome-wide patterns of variation     

Li JZ  Absher DM  Tang H  Southwick AM  Casto AM  Ramachandran S  Cann HM  Barsh GS  Feldman M  Cavalli-Sforza LL  Myers RM 《Science (New York, N.Y.)》2008,319(5866):1100-1104

Human genetic diversity is shaped by both demographic and biological factors and has fundamental implications for understanding the genetic basis of diseases. We studied 938 unrelated individuals from 51 populations of the Human Genome Diversity Panel at 650,000 common single-nucleotide polymorphism loci. Individual ancestry and population substructure were detectable with very high resolution. The relationship between haplotype heterozygosity and geography was consistent with the hypothesis of a serial founder effect with a single origin in sub-Saharan Africa. In addition, we observed a pattern of ancestral allele frequency distributions that reflects variation in population dynamics among geographic regions. This data set allows the most comprehensive characterization to date of human genetic variation.  相似文献   

Self-assembling protein microarrays     

Ramachandran N  Hainsworth E  Bhullar B  Eisenstein S  Rosen B  Lau AY  Walter JC  LaBaer J 《Science (New York, N.Y.)》2004,305(5680):86-90

Protein microarrays provide a powerful tool for the study of protein function. However, they are not widely used, in part because of the challenges in producing proteins to spot on the arrays. We generated protein microarrays by printing complementary DNAs onto glass slides and then translating target proteins with mammalian reticulocyte lysate. Epitope tags fused to the proteins allowed them to be immobilized in situ. This obviated the need to purify proteins, avoided protein stability problems during storage, and captured sufficient protein for functional studies. We used the technology to map pairwise interactions among 29 human DNA replication initiation proteins, recapitulate the regulation of Cdt1 binding to select replication proteins, and map its geminin-binding domain.  相似文献   

An M2 muscarinic receptor subtype coupled to both adenylyl cyclase and phosphoinositide turnover   总被引：20，自引：0，他引：20  

A Ashkenazi  J W Winslow  E G Peralta  G L Peterson  M I Schimerlik  D J Capon  J Ramachandran 《Science (New York, N.Y.)》1987,238(4827):672-675

To investigate whether a particular receptor subtype can be coupled to multiple effector systems, recombinant M2 muscarinic receptors were expressed in cells lacking endogenous receptor. The muscarinic agonist carbachol both inhibited adenylyl cyclase and stimulated phosphoinositide hydrolysis. The stimulation of phosphoinositide hydrolysis was significantly less efficient and more dependent on receptor levels than the inhibition of adenylyl cyclase. Both responses were mediated by guanine nucleotide binding proteins, as evidenced by their inhibition by pertussis toxin; the more efficiently coupled adenylyl cyclase response was significantly more sensitive. Thus, individual subtypes of a given receptor are capable of regulating multiple effector pathways.  相似文献   

Carboxyl terminal domain of Gs alpha specifies coupling of receptors to stimulation of adenylyl cyclase   总被引：13，自引：0，他引：13  

S B Masters  K A Sullivan  R T Miller  B Beiderman  N G Lopez  J Ramachandran  H R Bourne 《Science (New York, N.Y.)》1988,241(4864):448-451

The alpha subunits of Gs and Gi link different sets of hormone receptors to stimulation and inhibition, respectively, of adenylyl cyclase. A chimeric alpha i/alpha s cDNA was constructed that encodes a polypeptide composed of the amino terminal 60% of an alpha i chain and the carboxyl terminal 40% of alpha s. The cDNA was introduced via a retroviral vector into S49 cyc- cells, which lack endogenous alpha s. Although less than half of the hybrid alpha chain is derived from alpha s, its ability to mediate beta-adrenoceptor stimulation of adenylyl cyclase matched that of the normal alpha s polypeptide expressed from the same retroviral vector in cyc- cells. This result indicates that carboxyl terminal amino acid sequences of alpha s contain the structural features that are required for specificity of interactions with the effector enzyme, adenylyl cyclase, as well as with the hormone receptor.  相似文献