Multi-Scale Dimensions of Indigenous Land Tenure in the Amazon

This study demonstrates the importance of scale in understanding the common property institutions of indigenous groups in the Amazon. Using the example of the Pueblo Kichwa de Rukullakta, an ethnic Kichwa group in the Ecuadorian Amazon, we analyze land tenure arrangements at the household, community, and territory levels using a common property framework. The specific bundle of rights identified by the framework is held at the household level but households rely on community and territory level arrangements for their enforcement. Land claims at the community and territory level also serve to define the pool of legitimate rights holders at the next lower level. Due to the importance of scale in understanding indigenous land tenure generally, we suggest an adaptation of the common property framework to explicitly recognize the role of scale. This adapted framework identifies the function, characteristics, and means of enforcement for land claims at each scale of analysis.     

Steve Striffler: Solidarity: Latin America and the US Left in the era of human rights

Dialectical Anthropology -     

Regulation of specific genes during the cell cycle

Evidence for differential gene expresion during the cell cycle and approaches for studying cell-cycle-stage specific gene expression are summarized. Attention is focused on regulation of histone gene expression during the cell cycle of continuously dividing cells and after stimulation of nondividing cells to proliferate. The level(s) at which control of histone gene expression occurs and the possible involvement of chromosomal proteins in the regulation of histone gene expression are discussed. The preparation of cloned human histone sequences and their use in studying the structural and functional properties of human histone genes are presented.     

Spatial distribution of the medullary command signal within the electric organ of Gymnotus carapo

The pacemaker nucleus of Gymnotus carapo contains two types of neurons: pacemaker cells which set up the frequency of the electric organ discharge (EOD) and relay cells which convey the command signal to the spinal cord. Direct activation of a single relay cell provides enough excitation to discharge a pool of spinal electromotor neurons and electrocytes, generating a small EOD (unit EOD). Different relay cells generate unit EODs of variable size and waveform, indicating the involvement of different groups of electrocytes. A special technique of EOD recording (multiple air-gap) was combined with intracellular stimulation of relay cells to study the spatial distribution within the electric organ (EO) of the command signal arising from different relay cells. Three types of relay cells could be identified: type I commanding the rostral 10% of the EO, type II which distribute their command all along the EO and type III driving the caudal 30%. Waveform analysis of unit EODs indicates that doubly innervated electrocytes which are the most relevant for attaining the specific EOD waveform, receive a favored command from the pacemaker nucleus.Abbreviations CV conduction velocity - EMF electromotive force - EMN electromotor neuron - EO electric organ - EOD electric organ discharge - PN pacemaker nucleus - uEOD unit electric organ discharge