This article examines the development, early operation and subsequent failure of the Tot-Kolowa Red Cross irrigation scheme in Kenya’s Kerio Valley. Initially conceived as a technical solution to address regional food insecurity, the scheme aimed to scale up food production through the implementation of a fixed pipe irrigation system and the provision of agricultural inputs for cash cropping. A series of unfolding circumstances, however, necessitated numerous modifications to the original design as the project became increasingly entangled with deep and complex histories of land use patterns, resource allocation and conflict. Failure to understand the complexity of these dynamics ultimately led to the project’s collapse as the region spiralled into a period of significant unrest. In tracing these events, we aim to foreground the lived realities of imposed development, including both positive and negative responses to the scheme’s participatory obligations and its wider impact on community resilience.

The search for life in the Universe is a fundamental problem of astrobiology and modern science. The current progress in the detection of terrestrial-type exoplanets has opened a new avenue in the characterization of exoplanetary atmospheres and in the search for biosignatures of life with the upcoming ground-based and space missions. To specify the conditions favourable for the origin, development and sustainment of life as we know it in other worlds, we need to understand the nature of global (astrospheric), and local (atmospheric and surface) environments of exoplanets in the habitable zones (HZs) around G-K-M dwarf stars including our young Sun. Global environment is formed by propagated disturbances from the planet-hosting stars in the form of stellar flares, coronal mass ejections, energetic particles and winds collectively known as astrospheric space weather. Its characterization will help in understanding how an exoplanetary ecosystem interacts with its host star, as well as in the specification of the physical, chemical and biochemical conditions that can create favourable and/or detrimental conditions for planetary climate and habitability along with evolution of planetary internal dynamics over geological timescales. A key linkage of (astro)physical, chemical and geological processes can only be understood in the framework of interdisciplinary studies with the incorporation of progress in heliophysics, astrophysics, planetary and Earth sciences. The assessment of the impacts of host stars on the climate and habitability of terrestrial (exo)planets will significantly expand the current definition of the HZ to the biogenic zone and provide new observational strategies for searching for signatures of life. The major goal of this paper is to describe and discuss the current status and recent progress in this interdisciplinary field in light of presentations and discussions during the NASA Nexus for Exoplanetary System Science funded workshop ‘Exoplanetary Space Weather, Climate and Habitability’ and to provide a new roadmap for the future development of the emerging field of exoplanetary science and astrobiology.

In a community sample of the elderly (N = 274) in Hobart, Tasmania, cases of dementia and depression were ascertained by the Canberra Geriatric Mental State and the Mini Mental State Examination. Social relationships and support were examined by means of the Interview Schedule for Social Interaction. The elderly had fewer social relationships than younger adults, but were more content with what they did have. Elderly women had more affectional ties than elderly men. The presence of offspring in the same town increased the number of close ties and of social relationships, but was more important for men than for women. Persons with cognitive impairment or an established dementia reported that they had less social interaction than they would like. Depressed subjects reported having markedly less social interaction than the mentally healthy elderly, but did not complain that it was too little. This study provides a systematic description of the social environment of the elderly, both in mental health and in states of depression or impaired cognition.

Less educated elderly people are commonly found to perform more poorly on the Mini-Mental State Examination (MMSE). This educational level difference has been attributed by some research workers to test bias. To assess whether the MMSE is biased against the poorly educated, its validity was assessed separately in the more- and less-educated members of a community sample. No evidence was found to indicate that the test is a biased measure of cognitive impairment.

A survey was made of 274 non-institutionalized persons aged 70 and over living in Hobart. The prevalence of dementia and of depression was measured by interviewing subjects using a modified version of the Geriatric Mental State Schedule (GMS) (Copeland et al. 1976) and the Mini Mental State Examination (MMSE) (Folstein et al. 1975). Rates of morbidity were derived from different diagnostic procedures. These were: (1) diagnoses made by a psychiatrist (A.S.H.) directly from the interview schedules and audiotapes, and rated as mild, moderate or severe; (2) the criteria laid down in DSM-III, converted into algorithms describing 3 degrees of severity; and (3) the algorithms for pervasive dementia and depression proposed by Gurland et al. (1983), and from these authors' rational scales. In addition, the relation between scales for dementia and for depression and the diagnosed categories was examined. Some problems in applying these methods to aged persons in the community are discussed. It is concluded that more detailed specification of criteria is desirable if the comparative epidemiology of dementia and depression in old age is to advance.

Potential cases of presenile dementia of the Alzheimer type (PDAT) in the Northern Health Region (estimated population aged 45–64, 655800) were ascertained for the years 1979–86 from in-patient ICD-9 codes and other sources. An algorithm was applied to the casenote information to distinguish between Alzheimer-type and other forms of dementia. A search of the NHS central register was made to establish date and place of death. Estimates were made for patients with missing case records. The point prevalence rate for PDAT was estimated as 34·6 per 100000 with an annual incidence of 7·2 per 100000 in the 45–64 age range. These rates are compared with those reported in other studies. Five-year survival following diagnosis for incident cases of PDAT was 64% with a longevity quotient (LQ), the percentage of expected time actually survived, of 69%. There was no evidence of a more malignant course in PDAT when compared with survival in older patients with dementia of the Alzheimer type (DAT) in other studies. Sixty-six per cent of deaths occurred in hospital, 19% at home and 15% in residential homes.

Four diagnostic systems for dementia and depression are compared on a community sample of 274 subjects. They are: DSM-III, Gurland's system, AGECAT and a clinician's ratings. These are compared, not in the usual terms of prevalence rates and cross-tabulations of diagnostic categories, but by examining the performance of each system in terms of hypothetical, continuously distributed traits underlying the symptoms of dementia and depression, as in the latent trait model described by Duncan-Jones et al. (1986). Each diagnosis is characterized by the level of severity (threshold) at which it operates, and its accuracy. Evidence is given to support a dimensional view of dementia.

Three studies are reported using the Geriatric Mental State in one of its community forms on a total of 647 subjects aged over 65 and living in their own homes. The concordance between the computer diagnosis AGECAT and psychiatrists' diagnosis is at least as good in these replication samples as in the original studies (Copeland et al. 1986). AGECAT has been shown to be useful for epidemiological surveys and as a diagnostic guide for non-medical interviewers.

The scores of 269 depressed patients on the Depressive Category-Type Scale were analysed. The distributions of component and total scores were found to be bimodal, indicating that most depressed patients can be divided into an endogenous group and another characterized by the presence of neurotic features and the absence of endogenous ones. These findings were discussed in relation to those of other investigators. The relationship between the differentiation of syndromes and the classification of patients into corresponding diagnostic groups was considered. Finally, it was suggested that it should be interesting to try to estimate, from published data, the correlation between endogenous and neurotic depression in the general population.

Carcass characteristics were studied in young red deer raised on a Scottish hill farm with heather·dominant pasture. Stags slaughtered in September when 15 or 27 months old were very lean, and entire and castrate animals were similar in weight. At 15 months they were barely a half of their expected mature weight. With no pre-slaughter fasting, dressed carcass weight was 49–51% of live weight. A more detailed analysis of carcass conformation was made in a study of entire stags, castrate stags and hinds slaughtered when 15 months old after being held overnight without food or water. The three groups were similar in that their dressed carcasses weighed about 52% of live weight and the content of first class lean meat amounted to 32% of live weight. There was only 4·5% of chemical fat in the empty carcass.

The pH of the meat 36 h post mortem often remained high in the stag groups, relative to a mean value of pH 5·7 found in shot wild stags. This high-pH character was little affected by the severity of stress immediately before slaughter, nor by the availability of food. It seemed to be caused by holding the animals in unfamiliar surroundings for some 16 h before slaughter.

The extension of surfactant-based technologies for use in remediation of mercuric ion [Hg(II)]-impacted soils and ground-waters was explored. In concept, a target metal ion can be selectively sequestered and mobilized from the subsurface by a ligand solubilized in surfactant solution. The selected ligand, 1-decyl-2-thiourea (DTU), was used in this study due to its extremely high selectivity for Hg2+ and its compatibility with micellar solubilization. In batch semiequilibrium dialysis studies using a mixture of 0.3 mM DTU and 30 mM cetylpyridinium nitrate (a cationic surfactant), 99.8% of applied Hg(II) (0.1 mM) was retained, thus demonstrating the effectiveness of this ligand-surfactant system for separating the mobile contaminant from the waste stream. Isolation of the target metal ion from the complex is desirable to allow for ligand and surfactant reuse. As a function of the ligand type, this can be achieved by precipitation, pH stripping, or ligand-ligand exchange. In theory, for DTU, Hg(ll) removal can be done at an elevated pH by formation of a soluble mercury-hydroxide complex, which would pass a secondary ultrafiltration stage, allowing retention and reuse of the ligand-surfactant colloid. While only batch studies were conducted for this feasibility study, the possibility of utilizing flow-through ultrafiltration units coupled with contaminant isolation steps in pump-and-treat field applications is discussed.