Concentration of nitrate in the Guliya ice core from the Qinghai-Xizang Plateau and the solar activity

The variations of NO\+-\-3 concentration in the Guliya ice core are reconstructed for recent about 1 000 a. Spectrum analysis of NO\+-\-3 indicates significant periodicities in the variations of NO\+-\-3 concentration, which coincide with the periodicities of the solar activity. Therefore, a positive correlation between the variations of NO\+-\-3 concentration and the solar activity is found.     

Neuroimaging, nutrition, and iron-related genes

Several dietary factors and their genetic modifiers play a role in neurological disease and affect the human brain. The structural and functional integrity of the living brain can be assessed using neuroimaging, enabling large-scale epidemiological studies to identify factors that help or harm the brain. Iron is one nutritional factor that comes entirely from our diet, and its storage and transport in the body are under strong genetic control. In this review, we discuss how neuroimaging can help to identify associations between brain integrity, genetic variations, and dietary factors such as iron. We also review iron’s essential role in cognition, and we note some challenges and confounds involved in interpreting links between diet and brain health. Finally, we outline some recent discoveries regarding the genetics of iron and its effects on the brain, suggesting the promise of neuroimaging in revealing how dietary factors affect the brain.     

Purification of arginase

Résumé Nombreux sont les travaux qui traitent de la séparation et de la purification de l'arginase. Le présent travail décrit une méthode de purification qui permet d'obtenir une arginase active contenant des traces d'impuretés (80% d'arginase active).     

Nematidical activity of secondary and tertiary alkyl amides and amines.

Several C11 to C15 amides and amines that disrupt growth in certain insects showed high nematicidal activity in direct contact tests. Two amides and 9 amines killed Panagrellus at 5-10 ppm. Of these, 1 amide and 3 amines killed Meloidogyne larvae at 20 ppm.     

Nuclear pores in the spermatozoon of the rat.

The paper describes a hexagonal array of nuclear pores in a non-redundant region of the nuclear envelope underlying the basal surface of the rat spermatozoon head. It is concluded that intranuclear material protruding through these pores is the cause of the characteristic rows of circular 'bumps' found in surface replicas of this region.     

Interleukin-1 receptor antagonist reduces mortality from endotoxin shock

About five out of 1,000 patients admitted to hospital develop bacterial sepsis leading to shock, the mortality rate for which is high despite antibiotic therapy. The infection results in hypotension and poor tissue perfusion, and eventually leads to the failure of several organ systems. Bacterial endotoxin is thought to be the direct cause of shock in Gram-negative sepsis, because it can cause shock in animals, and antibodies against endotoxin prevent Gram-negative shock in animals and in humans. But, the symptoms of septic shock are the result of the actions of host cytokines induced by the endotoxin. The cytokine interleukin-1 has been implicated as an important mediator of septic shock because it can induce tachycardia and hypotension and act synergistically with tumour necrosis factor to cause tissue damage and death. We now report that a specific interleukin-1 receptor antagonist reduces the lethality of endotoxin-induced shock in rabbits, indicating that interleukin-1 does indeed play an important part in endotoxin shock.     

New species and a new combination of Mentzelia section Bartonia (Loasaceae) from the Colorado Plateau

A new species, Mentzelia (sect. Bartonia ) cronquistii , subfamily Mentzelioideae, is described and a new combination, M. (sect. Bartonia ) marginata (Osterhout) is made. These two species of the Colorado Plateau are closely related to each other, but their relationships to other species in section Bartonia are obscure.     

Glycoprotein organization of Chikungunya virus particles revealed by X-ray crystallography

Chikungunya virus (CHIKV) is an emerging mosquito-borne alphavirus that has caused widespread outbreaks of debilitating human disease in the past five years. CHIKV invasion of susceptible cells is mediated by two viral glycoproteins, E1 and E2, which carry the main antigenic determinants and form an icosahedral shell at the virion surface. Glycoprotein E2, derived from furin cleavage of the p62 precursor into E3 and E2, is responsible for receptor binding, and E1 for membrane fusion. In the context of a concerted multidisciplinary effort to understand the biology of CHIKV, here we report the crystal structures of the precursor p62-E1 heterodimer and of the mature E3-E2-E1 glycoprotein complexes. The resulting atomic models allow the synthesis of a wealth of genetic, biochemical, immunological and electron microscopy data accumulated over the years on alphaviruses in general. This combination yields a detailed picture of the functional architecture of the 25?MDa alphavirus surface glycoprotein shell. Together with the accompanying report on the structure of the Sindbis virus E2-E1 heterodimer at acidic pH (ref. 3), this work also provides new insight into the acid-triggered conformational change on the virus particle and its inbuilt inhibition mechanism in the immature complex.