Variation in interleukin 7 receptor alpha chain (IL7R) influences risk of multiple sclerosis

Multiple sclerosis is a chronic, often disabling, disease of the central nervous system affecting more than 1 in 1,000 people in most western countries. The inflammatory lesions typical of multiple sclerosis show autoimmune features and depend partly on genetic factors. Of these genetic factors, only the HLA gene complex has been repeatedly confirmed to be associated with multiple sclerosis, despite considerable efforts. Polymorphisms in a number of non-HLA genes have been reported to be associated with multiple sclerosis, but so far confirmation has been difficult. Here, we report compelling evidence that polymorphisms in IL7R, which encodes the interleukin 7 receptor alpha chain (IL7Ralpha), indeed contribute to the non-HLA genetic risk in multiple sclerosis, demonstrating a role for this pathway in the pathophysiology of this disease. In addition, we report altered expression of the genes encoding IL7Ralpha and its ligand, IL7, in the cerebrospinal fluid compartment of individuals with multiple sclerosis.     

Regulation of HERG (KCNH2) potassium channel surface expression by diacylglycerol

The HERG (KCNH2) channel is a voltage-sensitive potassium channel mainly expressed in cardiac tissue, but has also been identified in other tissues like neuronal and smooth muscle tissue, and in various tumours and tumour cell lines. The function of HERG has been extensively studied, but it is still not clear what mechanisms regulate the surface expression of the channel. In the present report, using human embryonic kidney cells stably expressing HERG, we show that diacylglycerol potently inhibits the HERG current. This is mediated by a protein kinase C-evoked endocytosis of the channel protein, and is dependent on the dynein–dynamin complex. The HERG protein was found to be located only in early endosomes and not lysosomes. Thus, diacylglycerol is an important lipid participating in the regulation of HERG surface expression and function.     

The methodological strategies of agroecological research and the values with which they are linked

The characteristic features of some of the methodological strategies adopted in scientific research in agroecology are discussed. They reflect that agroecology, as an approach to scientific research, is inextricably entangled with the other strands of agroecology (farming practice, social movement, political project); and that adopting agroecological strategies, and upholding the values of environmental sustainability, food sovereignty, social justice and democratic participation, mutually reinforce each other. After outlining the kinds of questions that agroecological research addresses so that it can produce knowledge that informs agroecological farming practices and the long term aspiration of agroecological movements to create an alternative agricultural/food system, and then making summary remarks about methodological strategies in general, three characteristic features of some agroecological strategies are introduced and discussed. The paper concludes with comments on the value of agroecological research.     

CO2 jets formed by sublimation beneath translucent slab ice in Mars' seasonal south polar ice cap

The martian polar caps are among the most dynamic regions on Mars, growing substantially in winter as a significant fraction of the atmosphere freezes out in the form of CO2 ice. Unusual dark spots, fans and blotches form as the south-polar seasonal CO2 ice cap retreats during spring and summer. Small radial channel networks are often associated with the location of spots once the ice disappears. The spots have been proposed to be simply bare, defrosted ground; the formation of the channels has remained uncertain. Here we report infrared and visible observations that show that the spots and fans remain at CO2 ice temperatures well into summer, and must be granular materials that have been brought up to the surface of the ice, requiring a complex suite of processes to get them there. We propose that the seasonal ice cap forms an impermeable, translucent slab of CO2 ice that sublimates from the base, building up high-pressure gas beneath the slab. This gas levitates the ice, which eventually ruptures, producing high-velocity CO2 vents that erupt sand-sized grains in jets to form the spots and erode the channels. These processes are unlike any observed on Earth.     

Making learning critical: Identity, emotion, and power in processes of management development

In recent years, a substantial volume of broadly critical knowledge of management and organization has been established, but comparatively little attention has been given to the question of how the insights of such knowledge might be communicated or applied pedagogically. The temptation or danger, arguably, is for critical knowledge to be substituted for the content of “traditional management education,” with minimal regard for its contribution to processes of personal, social, and organizational development. The chief purpose of this paper is to put some flesh on the claim that critical theory can make an important contribution to the principles and practice of management education. After summarizing some key differences between “traditional management education” and action learning (concerning learning and personal experience), these differences are illustrated by reference to a case study, which in turn, provides a basis for highlighting the relevance of critical thinking for addressing problems and issues thrown up through action learning for managers.     

Allozyme variability, isolation, and dispersal of Eusattus muricatus (Coleoptera: Tenebrionidae) within Silver State Dune Complex, Great Basin, western North America

Genetics of Eusattus muricatus (Coleoptera: Tenebrionidae) populations within Silver State Dune Complex in the northern Great Basin of North America were assayed using allozyme electrophoresis. Hierarchical F -statistics showed no significant population subdivision among 3 valleys comprising Silver State Dune Complex. A regression of estimated pairwise gene flow ( Nm ) against pairwise geographic distance was not significant for populations within these valleys, but it was significant over larger distances. A neighbor-joining phenogram did not represent geographic relationships among populations in the 3 valleys but reflected the past geologic history of these dunes. Pairwise divergence times were low (>7000 yr) for populations within Silver State Dune Complex but were high (>18,000 yr) in outgroups.     

Genetically effective and adult population sizes in the Apache silverspot butterfly, Speyeria nokomis apacheana (Lepidoptera: Mynphalidae)

Genetically effective and adult population sizes of the Apache silverspot butterfly ( Speyeria nokomiis apacheana ) from the Great Basin of North America were tracked from 1991 to 1997. Speyeria nokomis inhabits mesic habitats in the Great Basin, and its recent declines in abundance have raised concerns about its future persistence. Adult population size estimates determined from mark-recapture methods ranged from 100 to 1900 individuals from 1993 through 1997. Genetically effective population sizes based on temporal changes in allozyme frequencies ranged from less tha 1 individual to 20 individuals between 1991 and 1995. Despite these small annual estimates, it is likely that gene flow resulted in overestimation of genetically effective population sizes. These reusuts, combined with observations in the field, suggest that suitable but vacan habitat patches be maintained for potential recolonization by S. n. apacheana.