Theories of Nomadic Movement: A New Theoretical Approach for Understanding the Movement Decisions of Nenets and Komi Reindeer Herders

It is known that the relationship between humans and their animals is important for understanding many aspects of nomadic pastoralist systems, including nomadic movement. However, to date, these complex human–animal relations have not been analyzed in a way that has led to an explanatory model of nomadic movement capable of producing testable hypotheses. Based on ethnographic material collected amongst Komi and Nenets nomadic reindeer herders of the Russian Arctic, we argue that nomadic movements can be best understood as a product of the interplay that exists between animal behaviour and the herders’ skilful actions to (a) maintain herd cohesion and (b) avoid hazards, whilst deploying the minimum amount of resources (i.e., human/animal effort and use of equipment) on rounding up the herd, stopping and turning it. Ecological factors affect movement through their influence on animal behaviour, whereas non-ecological factors do so by influencing the herders’ skilful actions. We demonstrate that, based on these assumptions, it is possible to build a testable model explaining the movement of some nomadic groups.

Changing Access to Labor,Pastures, and Knowledge: The Extensification of Grazing Management in Sudano-Sahelian West Africa

The broader ecological and social contexts within which livestock husbandry of Sudano-Sahelian West Africa operates have changed significantly over the past thirty years. This study concerns how: (1) these broader trends have affected the quantity and quality of labor investments into livestock herding; and (2) the ecological and animal nutritional implications of observed variation in labor investments into herding. The study was conducted in a 500 km² area of western Niger using a combination of qualitative interviews of herders and herd managers, household composition surveys, herd composition monitoring, grazing management monitoring and georeferenced vegetation and livestock grazing itinerary data. Statistical analyses were performed using a two-staged approach: (1) analysis of the factors affecting the allocation of labor to herding at the level of the managing household; and (2) analysis of the effect of herd characteristics, season, microgeography and herders’ social position on herders’ effort and the nutritional and ecological impacts of these efforts. The results of these analyses support the conclusion that the changing regional context of livestock husbandry leads to a reduction in labor (quantity and quality) investment or an “extensification” of herding with significant implications for livestock productivity and the environment.

Resource Entitlement and Mobility of Pastoralists in the Yerer and Daketa Valleys,Eastern Ethiopia

Literature on the mobility of pastoralists and resource access is widely available, but conceptualization and understanding of the socioeconomic processes expected to affect the outcome are inconsistent. In this article, drawing on research conducted in the Yerer and Daketa Valleys, eastern Ethiopia, we use the notion of entitlements to examine how, under increasing pressure for resource access, various agro-pastoral households manage conflicting interests in common grazing resources. We observed that in times of drought and resource scarcity incumbent agro-pastoralists find peaceful sharing arrangements with intruding pastoralists. Asset-poor agro-pastoralists enter into mutually beneficial arrangements with pastoralists, trading their resource endowments to grazing land for other assets from the pastoralists, whereas wealthier households prefer a reciprocal risk-management strategy. These multiple arrangements have distributional effects because asset-poor agro-pastoralist households can stabilize or enhance their household assets and their capabilities in times of drought, and thus benefit from assisting pastoralist migrants to the common grazing land.

Objects limit human comprehension

This paper demonstrates that the human visual system, the primary sensory conduit for primates, processes ambient energy in a way that obligatorily constructs the objects that we ineluctably perceive. And since our perceptual apparatus processes information only in terms of objects (along with the properties and movements of objects), we are limited in our ability to comprehend ‘what is’ when we move beyond our ordinary world of midsize objects—as, for example, when we address the micro microworld of quantum physics.

Assessing the fitness landscape revolution

According to Pigliucci and Kaplan, there is a revolution underway in how we understand fitness landscapes. Recent models suggest that a perennial problem in these landscapes—how to get from one peak across a fitness valley to another peak—is, in fact, non-existent. In this paper I assess the structure and the extent of Pigliucci and Kaplan’s proposed revolution and argue for two points. First, I provide an alternative interpretation of what underwrites this revolution, motivated by some recent work on model-based science. Second, I show that the implications of this revolution need to carefully assessed depending on question being asked, for peak-shifting is not central to all evolutionary questions that fitness landscapes have been used to explore.

Predictive performance modelling of parallel component compositions

Large-scale scientific computing applications frequently make use of closely-coupled distributed parallel components. The performance of such applications is therefore dependent on the component parts and their interaction at run-time. This paper describes a methodology for predictive performance modelling and evaluation of parallel applications composed of multiple interacting components. In this paper, the fundamental steps and required operations involved in the modelling and evaluation process are identified—including component decomposition, component model combination, M×N communication modelling, dataflow analysis and overall performance evaluation. A case study is presented to illustrate the modelling process and the methodology is verified through experimental analysis.

Towards Endogenous Livestock Development: Borana Pastoralists’ Responses to Environmental and Institutional Changes

Borana pastoralists in southern Ethiopia are faced with the challenge of developing more efficient and sustainable use of natural resources. In past decades poorly adapted development interventions and inadequate land-use policies aggravated by population growth have weakened pastoral rangeland management. Ignoring pastoralists’ technical and organizational capacities has contributed to progressive land degradation, the erosion of social structures and poverty. The Endogenous Livestock Development concept recognises pastoralists’ indigenous knowledge-based strategies and priorities, and uses them as the bases for further development of their production system and social relations, to be utilized, improved and combined with modern technologies. This paper explores the Borana pastoralists’ adaptive strategies for improved utilization of natural resources and the manner in which they respond to environmental risk and external influences such as water development and new formal administration. The adaptive responses include controlled integration of crop production and protection of grazing reserves, as well as changing cattle breeding priorities and the adoption of camel husbandry. The pastoralists have started negotiations with the administration to regain control of land utilization by strengthening directives for settlements, land use pattern and extraction rates. To support these initiatives the study recommends that pastoralists and other stakeholders enter into an institutionalized process of negotiation that builds on indigenous knowledge and organizational structures and facilitates validation and implementation of newly generated knowledge.

Evolutionary Trends

The occurrence, generality, and causes of large-scale evolutionary trends—directional changes over long periods of time—have been the subject of intensive study and debate in evolutionary science. Large-scale patterns in the history of life have also been of considerable interest to nonspecialists, although misinterpretations and misunderstandings of this important issue are common and can have significant implications for an overall understanding of evolution. This paper provides an overview of how trends are identified, categorized, and explained in evolutionary biology. Rather than reviewing any particular trend in detail, the intent is to provide a framework for understanding large-scale evolutionary patterns in general and to highlight the fact that both the patterns and their underlying causes are usually quite complex.

Pastoralist Responses to Floodplain Rehabilitation in North Cameroon

This paper examines the responses of mobile pastoralists to a floodplain rehabilitation program in north Cameroon. From 1993 to 1999, we measured changes in number of camps and herds, and the time they spent in the 600 km² of the Logone floodplain that was reflooded in 1994. The first year, few pastoralists anticipated the reflooding or its impact, and the increase in grazing intensity was caused by a prolonged stay of pastoralists who already used the area for transit. The following three years showed a sharp increase in the number of camps and herds, which stabilized from 1997 onwards. Overall, grazing intensity increased threefold, following the gradually recovering perennial grasslands, with no signs of overexploitation of the area. These developments closely match the ideal preemptive distribution model. We also examined how reflooding affected pastoral incursions in the Waza National Park located in the floodplain.

The Social Impacts of Nanotechnology: an Ethical and Political Analysis

This paper attempts some predictions about the social consequences of nanotechnology and the ethical issues they raise. I set out four features of nanotechnology that are likely to be important in determining its impact and argue that nanotechnology will have significant social impacts in—at least—the areas of health and medicine, the balance of power between citizens and governments, and the balance of power between citizens and corporations. More importantly, responding to the challenge of nanotechnology will require confronting “philosophical” questions about the sort of society we wish to create and the role that technology might play in creating it. This in turn will require developing institutions and processes that allow the public to wield real power in relation to technological trajectories. My ultimate contention is that the immediate task established by the likely social impacts of nanotechnology is not so much to develop an ethics of nanotechnology as to facilitate an ethical conversation about nanotechnology.

Understanding Evolutionary Trees

Charles Darwin sketched his first evolutionary tree in 1837, and trees have remained a central metaphor in evolutionary biology up to the present. Today, phylogenetics—the science of constructing and evaluating hypotheses about historical patterns of descent in the form of evolutionary trees—has become pervasive within and increasingly outside evolutionary biology. Fostering skills in “tree thinking” is therefore a critical component of biological education. Conversely, misconceptions about evolutionary trees can be very detrimental to one’s understanding of the patterns and processes that have occurred in the history of life. This paper provides a basic introduction to evolutionary trees, including some guidelines for how and how not to read them. Ten of the most common misconceptions about evolutionary trees and their implications for understanding evolution are addressed.

Sudden Shift or Migratory Drift? FulBe Herd Movements to the Sudano-Guinean Region of West Africa

A significant change in the geography of livestock raising over the past 30 years is the southerly movement of FulBe herds into the humid Sudanian and Guinean savannas of West Africa. The literature suggests that the severe droughts of the early 1970s and mid-1980s were the driving force behind this southern expansion of mobile livestock raising. The conventional view is that drought forced herders to seek greener pastures to the south, an area that zebu cattle have previously avoided because of the presence of tsetse flies, the vector of animal sleeping sickness (trypanosomiasis). This “sudden push” hypothesis places Sahelian herds in savanna pastures in a matter of a 1–3 years. This stimulus-response model runs counter to our observations and understanding of the social and ecological processes influencing FulBe herd movements. We challenge the “sudden shift” thesis at the regional scale by arguing that the southerly expansion of FulBe herds has proceeded according to a more complex temporal frame that includes generational, biological, and social historical timeframes and periodicities. We distinguish between short-term shifts (“test movements”) and more permanent shifts (“migration movements”). These mobility patterns are linked to contingent factors such as cattle diseases, drought, and political instability, as well as to more structural and adaptive features such as the establishment of social networks, herding contracts, and cattle cross-breeding. Shifts in livestock ownership and the social differentiation among herders are important variables for understanding changes in herd movements. We conclude that the permanent shift of herds to the humid savannas of West Africa has been preceded by a series of social and agroecological adjustments that operate on decadal and generational time scales.

Entomopathogenic fungi as a potential control agent against the lesser mealworm, <Emphasis Type="Italic">Alphitobius diaperinus</Emphasis> in broiler houses

We tested the pathogenicity of 18 Metarhizium anisopliae (Metschn.) Sorokin isolates and 22 Beauveria bassiana (Balsamo) Vuillemin isolates against Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) larvae and adults. The efficacy of the most virulent isolate—M. anisopliae K—was evaluated in containers with a concrete bottom covered with wood shavings, under simulated poultry house conditions. Application of conidia of this isolate to the shavings or directly to the concrete bottom reduced the yield of larvae in 8–15 time compared with the control. In another test, the mortality of mature larvae placed on previously inoculated shavings or bottom reached 80–90% within 14 days, compared with 14% in the control. The residual activity of conidia kept at 28°C retained its initial level during 14 days post-inoculation, but declined after three weeks. Based on our data M. anisopliae has considerable potential for the control of A. diaperinus.

Is it a revolution?

Jablonka and Lamb's claim that evolutionary biology is undergoing a ‘revolution’ is queried. But the very concept of revolutionary change has uncertain application to a field organized in the manner of contemporary biology. The explanatory primacy of sequence properties is also discussed.

The Cauchy problem for one-dimensional spiking neuron models

I consider spiking neuron models defined by a one-dimensional differential equation and a reset—i.e., neuron models of the integrate-and-fire type. I address the question of the existence and uniqueness of a solution on for a given initial condition. It turns out that the reset introduces a countable and ordered set of backward solutions for a given initial condition. I discuss the implications of these mathematical results in terms of neural coding and spike timing precision.

<Emphasis Type="Italic">Hox</Emphasis> cluster duplication in the basal teleost <Emphasis Type="Italic">Hiodon alosoides</Emphasis> (Osteoglossomorpha)

Large-scale—even genome-wide—duplications have repeatedly been invoked as an explanation for major radiations. Teleosts, the most species-rich vertebrate clade, underwent a “fish-specific genome duplication” (FSGD) that is shared by most ray-finned fish lineages. We investigate here the Hox complement of the goldeye (Hiodon alosoides), a representative of Osteoglossomorpha, the most basal teleostean clade. An extensive PCR survey reveals that goldeye has at least eight Hox clusters, indicating a duplicated genome compared to basal actinopterygians. The possession of duplicated Hox clusters is uncoupled to species richness. The Hox system of the goldeye is substantially different from that of other teleost lineages, having retained several duplicates of Hox genes for which crown teleosts have lost at least one copy. A detailed analysis of the PCR fragments as well as full length sequences of two HoxA13 paralogs, and HoxA10 and HoxC4 genes places the duplication event close in time to the divergence of Osteoglossomorpha and crown teleosts. The data are consistent with—but do not conclusively prove—that Osteoglossomorpha shares the FSGD. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.

Risk Management by Communal Decision in Trans-Himalayan Farming: Manang Valley in Central Nepal

It is generally assumed that peasants optimize security of food supply rather than maximize profit. One way of securing the survival of the household is to spread risk in farming by extending the planting and harvesting seasons in order to avoid all crops being damaged if unfavorable production conditions should occur. It thus seems peculiar that some Himalayan peasant communities act in the opposite manner by compressing peak agricultural activity into a minimum period, and furthermore that all cultivators simultaneously start planting and harvesting on dates fixed by the village headman in consultation with a lama (Buddhist priest). Rather than suggesting that any single explanation for this practice is the right one, however, this article contends that specific farming system cannot be understood properly unless a combination of subsystems — or facets — are included in the analyses.

Amazon Forestry Tranformed: Integrating Knowledge for Smallholder Timber Managemet in Eastern Brazil

Recent discussions of local knowledge emphasize its dynamic nature invoking local peoples’ ability to effectively integrate traditional or local with science-based or “modern” knowledges. The smallholder timber industry of the Amazon’s estuarine floodplain provides an outstanding example of local patterns of resource management and economic activities transformed from within by smallholder farmers who participated in the industrial timber boom of the 1970s and 1980s. These farmers of eastern Amazonia have developed a vertically integrated local industry based on expertise reflecting profound locally developed knowledge of specific forests and management of ecological processes, individual observation and experimentation, as well as concepts and practices derived from temporary employment by large-scale industrial timber firms. At each stage of the smallholder forestry process—from managing natural regeneration to running small sawmills and marketing lumber—local managers apply an innovative set of practices reflecting their diverse experiences. This combination of technical, market, and ecological knowledge results in forests, timber markets, and economic patterns that do not correspond to many of the widely-held generalizations concerning either local or industrial tropical timber exploitation. This article uses data from 7 years of research in the Amazon floodplain.

Asymmetries in the Friendship Preferences and Social Styles of Men and Women

Several hypotheses on the form and function of sex differences in social behaviors were tested. The results suggest that friendship preferences in both sexes can be understood in terms of perceived reciprocity potential—capacity and willingness to engage in a mutually beneficial relationship. Divergent social styles may in turn reflect trade-offs between behaviors selected to maintain large, functional coalitions in men and intimate, secure relationships in women. The findings are interpreted from a broad socio-relational framework of the types of behaviors that facilitate selective advertisement and investment of reciprocity potential across individuals and within groups of men and women.