Design of bioelectronic interfaces by exploiting hinge-bending motions in proteins

We report a flexible strategy for transducing ligand-binding events into electrochemical responses for a wide variety of proteins. The method exploits ligand-mediated hinge-bending motions, intrinsic to the bacterial periplasmic binding protein superfamily, to establish allosterically controlled interactions between electrode surfaces and redox-active, Ru(II)-labeled proteins. This approach allows the development of protein-based bioelectronic interfaces that respond to a diverse set of analytes. Families of these interfaces can be generated either by exploiting natural binding diversity within the superfamily or by reengineering the specificity of individual proteins. These proteins may have numerous medical, environmental, and defense applications.     

Heterogeneity in soil chemistry relates to urbanization while soil homogeneity relates to plant invasion in small temperate deciduous forests

Landscape Ecology - Soil heterogeneity versus homogeneity patterns are observed within and across urban landscapes at multiple scales. To fully evaluate human-mediated influences on soil properties...     

The effect of feeding a sub-optimum level of lysine to female chicks on the amino acid content of selected tissues and organs

The amino acid content of the liver, brain, serum and leg muscle of broiler breeder female chicks was not influenced appreciably at 4 and 8 weeks of age by feeding a diet containing sub‐optimum levels of lysine. The feeding of the low‐lysine diet produced a slight effect on the amino acid content of the breast muscle and a decided effect on the amino acid content of the skin and bone marrow at 4 and 8 weeks of age. The amino acid content of the heart tissue from chicks which received the 0.53% lysine diet was higher at 4 weeks of age. No explanation for this observation can be offered. The more decided changes were produced in the bone marrow of the chicks fed the low‐lysine diet at 4 and 8 weeks of age.

There is a possibility that feeding the low‐lysine diet had an effect on protein synthesis in the bone marrow. Chicks fed the low‐lysine diet had apparently overcome the lysine deficiency in the synthesis of protein of the bone marrow at the end of the 12th week.     

Drivers of plant species richness and phylogenetic composition in urban yards at the continental scale

Landscape Ecology - As urban areas increase in extent globally, domestic yards play an increasingly important role as potential contributors to ecosystem services and well-being. These benefits...     

Molecular microscopy: fundamental limitations

On the basis of estimates of molecular damage caused by the observation process, it is concluded that molecular microscopy of biological molecules in which the individual atoms are resolved is impossible with an electron or x-ray microscope. Microscopes that use low-energy helium atoms or neutrons as illuminants may be capable of serving as ultimate biomolecular microscopes.     

Effect of feeding low lysine starters and developers on growth,sexual maturity and subsequent performance of broiler breeder pullets 1

Pullets that were fed diets containing 0.53 per cent and 0.42 per cent lysine grew at a slower rate and matured later than those that were given adequate amount of lysine. The latter pullets converted their food more efficiently than did the restricted pullets with the exception of the group fed the ration containing 0.53 per cent lysine for the first 12 weeks. The restricted pullets consumed less food during the growing period. A smaller bird was produced on less food. The restricted pullets were also lighter than the control pullets at the end of the laying season. A saving in food costs is indicated because the smaller hen would require less food for maintenance.

There was a higher mortality in the pullets fed a ration containing 0.53 per cent lysine during the growing period. The mortality in the group fed the ration containing 0.42 per cent lysine from 7 to 22 weeks of age was the same as that of the control. There were no differences in mortality during the laying season that could be related to methods of rearing the pullets.

During the laying season, the highest rate of lay was obtained from hens which had been fed the ration containing 0.42 per cent lysine from 7 to 22 weeks of age. Hens fed on the ration containing 0.53 per cent lysine from o to 4, 8 or 12 weeks of age showed no improvement in rate of lay as compared with controls.

Hens fed the ration containing 0.42 per cent lysine from 7 to 22 weeks laid fewer small eggs at the beginning of the laying season than did hens receiving adequate amounts of lysine throughout or fed the ration containing 0.53 per cent lysine from o to 4, 8 or 12 weeks. The hens fed the latter ration laid smaller eggs throughout the laying season.

No differences were found between the fertility, hatchability or embryonic mortality of eggs obtained from hens fed on lysine deficient diets during growth and those fed on diets adequate in lysine.     

Synergistic influence of Ostertagia ostertagi and Trichostrongylus axei on Ostertagia ostertagi larval inhibition and abomasal lesions in cattle

Parasite-free 4-month-old calves were inoculated with Ostertagia ostertagi and/or Trichostrongylus axei followed 6 weeks later by increasing doses of O ostertagi for 8 weeks. Clinical signs of parasitism, fecal egg counts, and plasma pepsinogen concentrations were monitored, and gross lesions and parasite burdens were determined postmortem. Clinical signs of parasitism were not observed and weight gains were not affected in experimentally infected calves. In calves infected with O ostertagi, mean plasma pepsinogen concentrations were greater than for control calves and were diagnostically significant 4 weeks after inoculation and during the last 4 weeks of serial inoculations with O ostertagi. In calves that were given O ostertagi and T axei, abomasal pH was significantly increased, and abomasal lesions were more pronounced than in control calves or in calves inoculated with only O ostertagi or T axei. Abomasal lymph nodes were enlarged in all parasitized calves; other lymph nodes in the calves inoculated with both O ostertagi and T axei were usually smaller than in calves inoculated with only O ostertagi or T axei. Numbers of O ostertagi-inhibited larvae were small in all inoculated calves, but the percentage inhibition was significantly greater in calves inoculated with both O ostertagi and T axei. The percentage inhibition was 3.53% for the O ostertagi-inoculated calves and 7.07% for calves inoculated with both O ostertagi and T axei. These percentages indicated a synergistic effect of concurrent abomasal parasitism, whereas a synergistic effect on T axei worm burden was not observed. The low percentage of larval inhibition indicated that factors other than host resistance are involved in naturally occurring pretype II ostertagiosis.