On the communication of well-being

The form that any communicatory exchange takes would depend on the extent to which the interests of the signaller and the recipient are at variance. Where such interests coincide, i.e. in cases of mutualism, the signals may be conspicuous when an immediate response is favoured, but rather subtle and variable otherwise. Over 80 % of the events of tactile communication that we have noted in our study of the social behaviour of free ranging groups of tame elephants appear to belong to this latter category. On Smith's standard classification, they can only be classified as 'associative', related to remaining in the company of another individual. However, such signals are commoner by a factor of 20-100 amongst elephant calves and their mothers and allomothers when compared to exchanges between adult cows. We suggest that the function of these signals is mutual monitoring of the state of well being amongst related individuals. The considerable degree of altruistic behaviour displayed in social groups, such as those of elephants is now believed to subserve the function of enhancing the inclusive fitness of the individuals concerned. We explore a mathematical model of exchange of social aid which suggests that animals in social groups may enhance their inclusive fitness further by adjusting the amount of social aid exchanged in relation to the state of well being of the donor as well as the recipient. Our model further suggests that optimal social aid depends on the state of well being in a complex fashion making it difficult for the recipient to deceive the donor so as to extract more aid. We therefore expect that by and large honest communication of the state of well being would be characteristic of the higher social animals. Such communication would be based on normal physiological changes consequent on a change in well being. Thus animals with a superior degree of well being would take postures conducive to greater activity, would be more receptive to sensory inputs and may also shift the balance of production of various metabolites. This monitoring of the well being has greatly advanced in the human species and may be at the base of the elaborate health care amongst human societies

A heavy winter monsoon rainfall episode influenced by easterly waves, a westerly trough, blocking and the ITCZ

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Observations on the natural history and population ecology of the social wasp Ropalidia marginata (Lep.) from Peninsular India (Hymenoptera: Vespidae)

Ropalidia marginata, the most common Indian social wasp, belongs to a crucial stage of social evolution showing no obvious morphological caste differentiation but a behavioural caste differentiation and a dominance hierarchy that appears to influence division of labour. The nests consist of a single open comb that can sometimes have up to 500 cells and 10 pedicels. Nests are initiated and abandoned all round the year. Initiation is by 1-20 foundresses, 1-4 being the most common number. There is a great deal of variation in brood developmental times both within and between nests. Male progeny disappear from the nest soon after emergence while daughters stay on at the parent nest for a mean period of about a month. Small nests have a single egg layer while large nests have two or more females with well developed ovaries that presumably lay eggs. Most nests are short-lived, small nests being highly susceptible to failure. Large nests are less susceptible to failure but the emergence of multiple egg layers reduces the average relatedness of workers to the brood which presumably is the cause for large scale emigrations from these nests. An interaction of ecological and soical factors therefore appears to determine the growth of a nest

On the patterns of tree diversity in the Western Ghats of India

We have explored in the Western Ghats the patterns of tree diversity in relation to vegetation types which have been primarily defined on the basis of structure and phenology, A total of 20,785 individuals, belonging to 398 species, were enumerated along 108 belt transects covering a total area of 75 ha, from localities that spanned the entire length of the hill chain of the Western Ghats (8°N to 21°N latitude and 73°E to 75°E longitude) in peninsular India. These transects were assigned to 7 vegetation types and were shown to be distinctive in species composition. These types include closed canopy evergreen, semi-closed canopy evergreen, stunted evergreen, semievergreen, moist deciduous, dry deciduous forests, and scrub/savanna vegetation. Dry deciduous forests with low levels of density and diversity harbour a rather exclusive set of species. The most diverse tree assemblages belong to the semievergreen forest type, which harbours widespread species extensively shared with other vegetation types. The semiclosed evergreen forests resemble semievergreen forests in many ways. In contrast, the stunted evergreen forests and scrub/savanna exhibit low values of tree density and diversity; their component species have very weak tendencies to co-occur with each other. The evergreen and moist deciduous forests exhibit moderate to high density and diversity and moderate levels of distinctiveness of species composition. The evergreen forests however resemble dry deciduous forests in harbouring species with a strong tendency to co-occur and many species with restricted distributions. More moist vegetation types shelter a higher proportion of evergreen and endemic trees and a lower proportion of medicinally-useful species. These results have significant implications for devising a sampling strategy

Effect of lopping intensity on tree growth and stand productivity in Tropical Forests

Effects of various intensities of lopping on the growth of trees, production of leafy biomass (leaves + shoots) and grass biomass production were investigated in the forests of the Western Ghats, India. Frequent complete lopping of trees resulted in a rapid drain of stored reserves leading to reduction in growth of tree girth and production of leafy biomass. Relatively greater increase in girth at the breast height of trees that were subjected to partial lopping, i.e. less than 50% intensity, was considered to be mainly the result of stimulation of remaining leaves to higher rates of photosynthesis. Opening of canopy increased the grass production in lopped quadrats. In two species, Aporosa lindleyana and Terminalia paniculata, the growth rate of girth and the yearly production of leafy biomass showed positive correlation up to 75% lopping intensity indicating that these two species can withstand lopping to some extent. For managing the forests and trees on an ecologically sustainable basis, the desired option recommended is to restrict lopping to less than 50% of the crown portion. Intensive long term studies, however, are required to suggest management practices

Impact of human extraction on tropical humid forests in the Western Ghats Uttara Kannada, South India

1. Thirty strip transects of 2400 m2 each, in the evergreen forest tract of the district of Uttara Kannada in South India; were clustered into two groups with high and low levels of disturbance on the basis of the density of perennial flowering plants and the fraction of deciduous species. 2. The set of 20 transects corresponding to low disturbance localities harboured 48 ± 6 (mean ± SD) species and 694 ± 135 individuals per transect, while the other 10 transects affected by high levels of disturbance supported 36 ± 12 species and 379 ± 135 individuals. 3. Eighty-four of the total of 200 species (operational taxonomic units) were exclusive to sites of low disturbance, and 28 to those of high disturbance; 88 species were shared by sites of high and low disturbance. This number of shared species was significantly less than expected on the basis of chance alone. 4. The differences in species richness, as well as those in species turnover (0.73 ± 0.07 for high and 0.65 ± 0.01 for low disturbance sites) were significant at the 1% level, but were as expected given the lower plant densities at sites of high disturbance. 5. Lack of coppicing ability in conjunction with their use in the plywood/matchwood industry has led to the disappearance of several evergreen species such as Syzigium gardneri and Myristica malabarica at sites with high levels of disturbance. 6. With villagers concentrating on harvests of trees in the height class of 4-8 m as poles, and commercial interests mostly extracting trees > 16 m in height, there was a reduction of around 45% across all height classes between sites of low and high levels of disturbance

Indoor-Outdoor Air Leakage of Apartments and Commercial Buildings

We compiled and analyzed available data concerning indoor-outdoor air leakage rates and building leakiness parameters for commercial buildings and apartments. We analyzed the data, and reviewed the related literature, to determine the current state of knowledge of the statistical distribution of air exchange rates and related parameters for California buildings, and to identify significant gaps in the current knowledge and data. Very few data were found from California buildings, so we compiled data from other states and some other countries. Even when data from other developed countries were included, data were sparse and few conclusive statements were possible. Little systematic variation in building leakage with construction type, building activity type, height, size, or location within the u.s. was observed. Commercial buildings and apartments seem to be about twice as leaky as single-family houses, per unit of building envelope area. Although further work collecting and analyzing leakage data might be useful, we suggest that a more important issue may be the transport of pollutants between units in apartments and mixed-use buildings, an under-studied phenomenon that may expose occupants to high levels of pollutants such as tobacco smoke or dry cleaning fumes

Evaluating bird communities of Western Ghats to plan for a biodiversity friendly development

Reconciling development with conservation of biological diversity has emerged as a significant concern in recent years. This has been primarily attempted through establishment of protected areas taken out of mainstream development, and through regulating impacts of major development projects with the help of environmental impact assessment exercises. We believe that these two instruments need to be complemented by continually providing inputs into the biodiversity implications of ongoing development processes (and accompanying habitat transformations) at the landscape and regional level. It is desirable that such assessment of biodiversity implications is based on a transparent, objective methodology which could be used by a wide range of practitioners working with the emerging decentralized processes of development planning. In this paper we outline such a methodology focussing on birds. This involves assigning a conservation value to bird species based on readily available information on their geographical range, habitat preference, endangerment and taxonomic distinctiveness. This may then be translated into a mean composite conservation value for bird assemblages characteristic of different habitat types. By combining this information with that on ongoing processes of habitat transformations, we can provide an assessment of how development processes are affecting biodiversity values. We illustrate this methodology by assessing the conservation value of 586 bird species of Western Ghats, and a sample of bird assemblages of seven major habitat types of the region. We conclude that the most serious loss of biodiversity value arises in the transformation of montane evergreen shola forests/high altitude grasslands into monoculture plantations

Algorithm for Rapid Tomography of Gas Concentrations

We present a new computed tomography method, the low third derivative (LTD) method, that is particularly suited for reconstructing the spatial distribution of gas concentrations from path-integral data for a small number of optical paths. The method finds a spatial distribution of gas concentrations that (1) has path integrals that agree with measured path integrals, and (2) has a low third spatial derivative in each direction, at every point. The trade-off between (1) and (2) is controlled by an adjustable parameter, which can be set based on analysis of the path-integral data. The method produces a set of linear equations, which can be solved with a single matrix multiplication if the constraint that all concentrations must be positive is ignored; the method is therefore extremely rapid. Analysis of experimental data from thousands of concentration distributions shows that the method works nearly as well as Smooth Basis Function Minimization (the best method previously available), yet is 100 times faster

Effectiveness of Urban Shelter-in-Place. II: ResidentialDistricts

In the event of a short-term, large-scale toxic chemical release to the atmosphere, shelter-in-place (SIP) may be used as an emergency response to protect public health. We modeled hypothetical releases using realistic, empirical parameters to explore how key factors influence SIP effectiveness for single-family dwellings in a residential district. Four classes of factors were evaluated in this case-study: (a) time scales associated with release duration, SIP implementation delay, and SIP termination; (b) building air-exchange rates, including air infiltration and ventilation; (c) the degree of sorption of toxic chemicals to indoor surfaces; and (d) the shape of the dose-response relationship for acute adverse health effects. Houses with lower air leakage are more effective shelters, and thus variability in the air leakage of dwellings is associated with varying degrees of SIP protection in a community. Sorption on indoor surfaces improves SIP effectiveness by lowering the peak indoor concentrations and reducing the amount of contamination in the indoor air. Nonlinear dose-response relationships imply substantial reduction in adverse health effects from lowering the peak exposure concentration. However, if the scenario is unfavorable for sheltering (e.g. sheltering in leaky houses for protection against a nonsorbing chemical with a linear dose-response), the community must implement SIP without delay and exit from shelter when it first becomes safe to do so. Otherwise, the community can be subjected to even greater risk than if they did not take shelter indoors