Globalization and the sociology of Immanuel Wallerstein: A critical appraisal

By the turn of the 21st century the concept of globalization had earned its place in the social sciences and debate turned more squarely to the theoretical significance of globalization. Yet not all scholars were happy with the notion of globalization. Some claim that is merely a new name for earlier theories and concepts. Among those who reject new paradigmatic thinking on the current age is Immanuel Wallerstein, the world-renowned sociologist and ‘father’ of the worldsystem paradigm. This article is intended as an appraisal of Wallerstein’s oeuvre in the context of the debate on global transformations in the late 20th and early 21st centuries and from the vantage point of the present author’s own critical globalization perspective. The first three parts summarize and assess Wallerstein’s theoretical system and his many contributions to macro, historical and comparative sociology, to development studies and international political economy. The fourth discusses Wallerstein’s assessment of the evolution of the world capitalist system in recent decades, including his views on the concept of globalization, and the fifth focuses on earlier and more recent critical appraisals of his work, including the present author’s own, in light of the recent transformations in world capitalism identified with globalization

Managed Metapopulations: Do Salmon Hatchery ‘Sources’ Lead to In-River ‘Sinks’ in Conservation?

Maintaining viable populations of salmon in the wild is a primary goal for many conservation and recovery programs. The frequency and extent of connectivity among natal sources defines the demographic and genetic boundaries of a population. Yet, the role that immigration of hatchery-produced adults may play in altering population dynamics and fitness of natural populations remains largely unquantified. Quantifying, whether natural populations are self-sustaining, functions as sources (population growth rate in the absence of dispersal, λ>1), or as sinks (λ<1) can be obscured by an inability to identify immigrants. In this study we use a new isotopic approach to demonstrate that a natural spawning population of Chinook salmon, (Oncorhynchus tshawytscha) considered relatively healthy, represents a sink population when the contribution of hatchery immigrants is taken into consideration. We retrieved sulfur isotopes (34S/32S, referred to as δ34S) in adult Chinook salmon otoliths (ear bones) that were deposited during their early life history as juveniles to determine whether individuals were produced in hatcheries or naturally in rivers. Our results show that only 10.3% (CI = 5.5 to 18.1%) of adults spawning in the river had otolith δ34S values less than 8.5‰, which is characteristic of naturally produced salmon. When considering the total return to the watershed (total fish in river and hatchery), we estimate that 90.7 to 99.3% (CI) of returning adults were produced in a hatchery (best estimate = 95.9%). When population growth rate of the natural population was modeled to account for the contribution of previously unidentified hatchery immigrants, we found that hatchery-produced fish caused the false appearance of positive population growth. These findings highlight the potential dangers in ignoring source-sink dynamics in recovering natural populations, and question the extent to which declines in natural salmon populations are undetected by monitoring programs

Astrocytes contain a vesicular compartment that is competent for regulated exocytosis of glutamate.

Astrocytes establish rapid cell-to-cell communication through the release of chemical transmitters. The underlying mechanisms and functional significance of this release are, however, not well understood. Here we identify an astrocytic vesicular compartment that is competent for glutamate exocytosis. Using postembedding immunogold labeling of the rat hippocampus, we show that vesicular glutamate transporters (VGLUT1/2) and the vesicular SNARE protein, cellubrevin, are both expressed in small vesicular organelles that resemble synaptic vesicles of glutamatergic terminals. Astrocytic vesicles, which are not as densely packed as their neuronal counterparts, can be observed in small groups at sites adjacent to neuronal structures bearing glutamate receptors. Fluorescently tagged VGLUT-containing vesicles were studied dynamically in living astrocytes by total internal reflection fluorescence (TIRF) microscopy. After activation of metabotropic glutamate receptors, astrocytic vesicles underwent rapid (milliseconds) Ca(2+)- and SNARE-dependent exocytic fusion that was accompanied by glutamate release. These data document the existence of a Ca(2+)-dependent quantal glutamate release activity in glia that was previously considered to be specific to synapses