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(1) To increase awareness of the challenges induced by imperfect detection, which is a fundamental issue in species distribution modelling; (2) to emphasize the value of replicate observations for species distribution modelling; and (3) to show how 'cheap' checklist data in faunal/floral databases may be used for the rigorous modelling of distributions by site-occupancy models. Switzerland. We used checklist data collected by volunteers during 1999 and 2000 to analyse the distribution of the blue hawker, Aeshna cyanea (Odonata, Aeshnidae), a common dragonfly in Switzerland. We used data from repeated visits to 1-ha pixels to derive 'detection histories' and apply site-occupancy models to estimate the 'true' species distribution, i.e. corrected for imperfect detection. We modelled blue hawker distribution as a function of elevation and year and its detection probability of elevation, year and season. The best model contained cubic polynomial elevation effects for distribution and quadratic effects of elevation and season for detectability. We compared the site-occupancy model with a conventional distribution model based on a generalized linear model, which assumes perfect detectability (p = 1). The conventional distribution map looked very different from the distribution map obtained using site-occupancy models that accounted for the imperfect detection. The conventional model underestimated the species distribution by 60%, and the slope parameters of the occurrence-elevation relationship were also underestimated when assuming p = 1. Elevation was not only an important predictor of blue hawker occurrence, but also of the detection probability, with a bell-shaped relationship. Furthermore, detectability increased over the season. The average detection probability was estimated at only 0.19 per survey. Conventional species distribution models do not model species distributions per se but rather the apparent distribution, i.e. an unknown proportion of species distributions. That unknown proportion is equivalent to detectability. Imperfect detection in conventional species distribution models yields underestimates of the extent of distributions and covariate effects that are biased towards zero. In addition, patterns in detectability will erroneously be ascribed to species distributions. In contrast, site-occupancy models applied to replicated detection/non-detection data offer a powerful framework for making inferences about species distributions corrected for imperfect detection. The use of 'cheap' checklist data greatly enhances the scope of applications of this useful class of models.

Drawing on recent developments in field theory, this article analyzes the struggle for survival of São Paulo's street vendors in the face of a massive eviction campaign. I conceive of street vending as a social field divided into two unequal categories—licensed street vendors and unlicensed street vendors— and show that responses to the campaign varied along group lines. Unlicensed peddlers either abandoned the field or drew on local networks to continue peddling under harsher conditions, whereas licensed street vendors relied on wellestablished ties to actors in the political field. After these ties proved ineffective, licensed street vendors survived thanks to the intervention of a non-governmental organization (NGO) that activated the judicial field and mobilized the legal capital vested in the licenses. The linkage role performed by this actor with cross-field networks and expertise shows the strategic import of interfield relations, which replicate and reinforce the unequal distribution of assets inside the field.

This study investigates the widely overlooked phenomenon of multinational enterprise (MNE) location avoidance, utilizing a multi-method research design and data on 131 foreign investment locations. It complements economic-choice-based location research by adding contextual dimensions at the country level that matter to managers personally, and affect decisions at the firm level. We provide a connection between international business research, the behavioral stream in economic geography, and the microfoundations stream in the strategic management literature. The results suggest that, in addition to traditional location choice criteria (including investment potential, internationalization strategy, and various geographic and psychic distances), foreign location decisions in MNEs are influenced by how troublesome it is for managers to travel to or live in certain places. An 11-item measure composed of travel inconveniences shows a significant negative moderating effect on the relationship between foreign direct investment potential and investment intensity. The effect is stronger for non-resource-seeking industries. We call this phenomenon the \"hassle factor\".

In this article, I draw from fieldwork on the micropractices of hawkers' illicit dealings with low-level state functionaries in Mumbai, India, to explore how claims to city space are negotiated. I argue that what is often understood as a breakdown in urban governance is, instead, what I call an \"ordinary space of negotiation\" that constitutes the grounds on which claims to substantive citizenship are made. This ethnographic exploration of what practices of corruption produce has the possibility to expand how scholars think about the state and political claim making in liberal democratic contexts at large.

There is a consensus that urban development schemes in India bear little resemblance to the well-thought-out plans of their genesis, and that the boundary between formal/informal is often blurry. I seek to contribute to this literature by showing how, in spite of efforts to implement a regulatory scheme, street hawking in Delhi remains highly informal and in a state of negotiated (im)permanence. I compare two recent conflicts over street hawkers’ use of public space, which demonstrate that power is dispersed across a range of sites and rests with a number of state and non-state actors. I argue that preconceived notions of ‘formality’ and ‘informality’ are of little value in understanding urban processes, and instead it is necessary to understand how the boundary between formal/informal is produced and contested both juridically and through everyday practices of enforcement and evasion/subversion.

Dendrimers are globular, size monodisperse macromolecules in which all bonds emerge radially from a central focal point or core with a regular branching pattern and with repeat units that each contribute a branch point. Frechet relates the concept of dendrimers and supramolecular chemistry.

In this paper, we present an exact algorithm to find all extreme supported nondominated points of multiobjective mixed integer programs. The algorithm uses a composite linear objective function and finds all the desired points in a finite number of steps by changing the weights of the objective functions in a systematic way. We develop further variations of the algorithm to improve its computational performance and demonstrate our algorithm's performance on multiobjective assignment, knapsack, and traveling salesperson problems with three and four objectives.

As informal commerce has grown to become the lifeblood of African cities, street trade—among the largest sub-groups in the informal economy—has become a visible but contested domain. Yet the increase in street traders has not been accompanied by a corresponding improvement in their status as citizens or in their political influence.The paper first discusses the implications of theoretical debates on 'citizenship' and 'Voice' for street traders and then explores characteristics of traders' associations and influence in four case study countries: Senegal, Ghana, Tanzania and Lesotho. Drawing together the authors' findings from research between 2001 and 2008, the paper identifies a fluidity of both formal and informal traders' organisations which fail to achieve lasting impact. Finally, the paper discusses urban policy implications, arguing for a more flexible definition of urban citizenship based on rights and responsibilities, and an understanding of the complexity of grassroots associations of the marginalised poor.

We studied bats migrating and foraging over the sea by direct observations and automatic acoustic recording. We recorded 11 species (of a community of 18 species) flying over the ocean up to 14 km from the shore. All bats used sonar during migration flights at sea, often with slightly lower frequencies and longer pulse intervals compared to those used over land. The altitude used for migration flight was most often <10 m above sea level. Bats must use other sensory systems for long-distance navigation, but they probably use echoes from the water surface to orient to the immediate surroundings. Both migrant and resident bats foraged over the sea in areas with an abundance of insects in the air and crustaceans in the surface waters. When hunting insects near vertical objects such as lighthouses and wind turbines, bats rapidly changed altitude, for example, to forage around turbine blades. The findings illustrate why and how bats might be exposed to additional mortality by offshore wind power.