Anthropogenic Space Weather

Anthropogenic effects on the space environment started in the late 19th century and reached their peak in the 1960s when high-altitude nuclear explosions were carried out by the USA and the Soviet Union. These explosions created artificial radiation belts near Earth that resulted in major damages to several satellites. Another, unexpected impact of the high-altitude nuclear tests was the electromagnetic pulse (EMP) that can have devastating effects over a large geographic area (as large as the continental United States). Other anthropogenic impacts on the space environment include chemical release ex- periments, high-frequency wave heating of the ionosphere and the interaction of VLF waves with the radiation belts. This paper reviews the fundamental physical process behind these phenomena and discusses the observations of their impacts.Comment: 71 pages, 35 figure

Regulation of expression of the pea plastocyanin gene

SIGLEAvailable from British Library Document Supply Centre-DSC:D064170 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Isolation of an ent-kaurene oxidase cDNA from Cucurbita maxima

Four distinct cDNAs isolated from developing Cucurbita maxima Duchesne seeds included CYP701A1, a member of the same subfamily of cytochrome P450 enzyme as the Arabidopsis ent-kaurene oxidase GA3 which catalyses an early step in gibberellin (GA) biosynthesis. We have shown by complementation of the Arabidopsis ga3-2 mutant that the CYP701A1 cDNA encodes an ent-kaurene oxidase activity. Another cDNA, CYP88A2, encodes a protein which is in the same subfamily as the maize Dwarf3 protein and is likely to encode another GA biosynthetic enzyme catalysing a reaction between ent-kaurenoic acid and GA12

A Repressor Complex Governs the Integration of Flowering Signals in Arabidopsis

10.1016/j.devcel.2008.05.002Developmental Cell151110-120DCEE

Folate acts in E. coli to accelerate C. elegans aging independently of bacterial biosynthesis

Folates are cofactors for biosynthetic enzymes in all eukaryotic and prokaryotic cells. Animals cannot synthesize folate and must acquire it from their diet or microbiota. Previously, we showed that inhibiting E. coli folate synthesis increases C. elegans lifespan. Here, we show that restriction or supplementation of C. elegans folate does not influence lifespan. Thus, folate is required in E. coli to shorten worm lifespan. Bacterial proliferation in the intestine has been proposed as a mechanism for the life-shortening influence of E. coli. However, we found no correlation between C. elegans survival and bacterial growth in a screen of 1,000+ E. coli deletion mutants. Nine mutants increased worm lifespan robustly, suggesting specific gene regulation is required for the life-shortening activity of E. coli. Disrupting the biosynthetic folate cycle did not increase lifespan. Thus, folate acts through a growth-independent route in E. coli to accelerate animal aging

Patients’ perspectives on systemic sclerosis-related Raynaud's phenomenon in the feet: A qualitative study from the OMERACT Foot and Ankle Working Group

Objective To explore, from patients’ perspectives, the symptoms and impact of Raynaud's phenomenon (RP) on the feet of patients with systemic sclerosis (SSc-RP), and to identify which foot-related domains are important to patients. Methods Forty participants (34 women) with SSc-RP took part in one of six focus groups held in the United Kingdom or United States. Participants were purposively sampled to ensure diversity in disease type, duration, and ethnicity. The topic guide included questions on RP impact, self-management, and treatment expectations. Qualitative content analysis was employed to identify key concepts in the data relating to foot-specific symptoms and their impact. Themes were organized by corresponding domains of potential importance. Results Twenty-eight participants (70 %) reported experiencing RP in their feet. Five themes were identified corresponding to domains of potential importance: temperature changes, pain, cramping and stiffness, numbness, and color changes. These issues negatively affected participants’ lives, impairing walking, driving, and socializing, and causing issues with footwear and hosiery. Conclusions This large qualitative study exploring the experiences of patients with SSc-RP in the feet identified several key domains of high importance to patients. SSc-RP is common in the feet, presents in several patterns, and impacts multiple aspects of patients’ lives. These findings indicate where future foot-specific interventions for RP could be targeted. Findings from this study improve understanding of what domains are important to patients with SSc-RP affecting the feet and will contribute to the development of a core outcome set for foot and ankle disorders in rheumatic and musculoskeletal diseases

Seasonal differences in the effect of isolation and restraint stress on the luteinizing hormone response to gonadotropin-releasing hormone in hypothalamopituitary disconnected, gonadectomized rams and ewes

Stress responses are thought to act within the hypothalamopituitary unit to impair the reproductive system, and the sites of action may differ between sexes. The effect of isolation and restraint stress on pituitary responsiveness to GnRH in sheep was investigated, with emphasis on possible sex differences. Experiments were conducted during the breeding season and the nonbreeding season. In both experiments, 125 ng of GnRH was injected i.v. every 2 h into hypothalamopituitary disconnected, gonadectomized rams and ewes on 3 experimental days, with each day divided into two periods. During the second period on Day 2, isolation and restraint stress was imposed for 5.5 h. Plasma concentrations of LH and cortisol were measured in samples of blood collected from the jugular vein. In the second experiment (nonbreeding season), plasma concentrations of epinephrine, norepinephrine, 3,4-dihydroxyphenylalanine, and 3,4-dihydroxyphenylglycol were also measured. In both experiments, there was no effect of isolation and restraint stress on plasma concentrations of cortisol in either sex. During the breeding season, there was no effect of isolation and restraint stress on plasma concentrations of LH in either sex. During the nonbreeding season, the amplitude of the first LH pulse after the commencement of stress was significantly reduced (P &lt; 0.05) in rams and ewes. In the second experiment, during stress there was a significant increase (P &lt; 0.05) in plasma concentrations of epinephrine in rams and ewes and significantly higher (P &lt; 0.05) basal concentrations of norepinephrine in ewes than in rams. These results suggest that in sheep stress reduces responsiveness of the pituitary gland to exogenous GnRH during the nonbreeding season but not during the breeding season, possibly because of mediators of the stress response other than those of the hypothalamus-pituitary-adrenal gland axis.<br /