We investigate the spatial distribution, spectral properties and temporal variability of primary producers (e.g. communities of microbial mats and mosses) throughout the Fryxell basin of Taylor Valley, Antarctica, using high-resolution multispectral remote-sensing data. Our results suggest that photosynthetic communities can be readily detected throughout the Fryxell basin based on their unique near-infrared spectral signatures. Observed intra- and inter-annual variability in spectral signatures are consistent with short-term variations in mat distribution, hydration and photosynthetic activity. Spectral unmixing is also implemented in order to estimate mat abundance, with the most densely vegetated regions observed from orbit correlating spatially with some of the most productive regions of the Fryxell basin. Our work establishes remote sensing as a valuable tool in the study of these ecological communities in the McMurdo Dry Valleys and demonstrates how future scientific investigations and the management of specially protected areas could benefit from these tools and techniques.

The human intestine is colonised by 1013 to 1014 micro-organisms, the vast majority of which belong to the phyla Firmicutes and Bacteroidetes. Although highly stable over time, the composition and activities of the microbiota may be influenced by a number of factors including age, diet and antibiotic treatment. Although perturbations in the composition or functions of the microbiota are linked to inflammatory and metabolic disorders (e.g. inflammatory bowel diseases, irritable bowel syndrome and obesity), it is unclear at this point whether these changes are a symptom of the disease or a contributing factor. A better knowledge of the mechanisms through which changes in microbiota composition (dysbiosis) promote disease states is needed to improve our understanding of the causal relationship between the gut microbiota and disease. While evidence of the preventive and therapeutic effects of probiotic strains on diarrhoeal illness and other intestinal conditions is promising, the exact mechanisms of the beneficial effects are not fully understood. Recent studies have raised the question of whether non-viable probiotic strains can confer health benefits on the host by influencing the immune system. As the potential health effect of these non-viable bacteria depends on whether the mechanism of this effect is dependent on viability, future research needs to consider each probiotic strain on a case-by-case basis. The present review provides a comprehensive, updated overview of the human gut microbiota, the factors influencing its composition and the role of probiotics as a therapeutic modality in the treatment and prevention of diseases and/or restoration of human health.

Among the foreign policies of the new states which have emerged from the Western colonial empires, that of India occupies a leading place. The first non-Western nation to become a member of the British Commonwealth, India became a symbol and catalyst of self-determination for several nationalist movements. India proceeded on an “independent” path in world politics and had numerous emulators in the world. Where India's role in the state-making revolution has met with considerable approval, its strategy of nonalignment has been debated in the West, and even in India since the open appearance in 1959 of the Sino-Indian dispute. The criticism has included questions about the wisdom of nonalignment, doubts as to its feasibility, and charges that its application has shown preference for the communist states during periods of the Cold War. The Indian defense includes assertions that nonalignment serves India's welfare and often the world's, answers about its workability, and claims that application has been consistent with professed ideals.

Late last year the British Government emerged with its principles intact from a contest of wills with a Provisional IRA hunger-striker who sought changes in the prison treatment of those claiming political motivations for their acts of violence. When the hunger-striker broke his fast, it appeared that the British policy was vindicated. But as usual in Northern Ireland, the ascendency of British law and order did not go untested for long. In the spring of 1981 the Ulster situation erupted again when another IRA hunger-striker induced his own death after failing to produce any modification of prison rules. Although the Thatcher government had held firm once again, the tradition of Irish self-sacrifice was reborn. Bobby Sands, M.P., became the thirteenth Republican prisoner since 1920 to die on a hunger strike in jail, the first in the Republic itself.