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Preface paper to the Semi-Arid Land-Surface-Atmosphere (SALSA) Program special issue
The Semi-Arid Land-Surface-Atmosphere Program (SALSA) is a multi-agency, multi-national research effort that seeks to evaluate the consequences of natural and human-induced environmental change in semi-arid regions. The ultimate goal of SALSA is to advance scientific understanding of the semi-arid portion of the hydrosphere–biosphere interface in order to provide reliable information for environmental decision making. SALSA approaches this goal through a program of long-term, integrated observations, process research, modeling, assessment, and information management that is sustained by cooperation among scientists and information users. In this preface to the SALSA special issue, general program background information and the critical nature of semi-arid regions is presented. A brief description of the Upper San Pedro River Basin, the initial location for focused SALSA research follows. Several overarching research objectives under which much of the interdisciplinary research contained in the special issue was undertaken are discussed. Principal methods, primary research sites and data collection used by numerous investigators during 1997–1999 are then presented. Scientists from about 20 US, five European (four French and one Dutch), and three Mexican agencies and institutions have collaborated closely to make the research leading to this special issue a reality. The SALSA Program has served as a model of interagency cooperation by breaking new ground in the approach to large scale interdisciplinary science with relatively limited resources
Transcriptome profiling of ontogeny in the acridid grasshopper Chorthippus biguttulus
Acridid grasshoppers (Orthoptera:Acrididae) are widely used model organisms
for developmental, evolutionary, and neurobiological research. Although there
has been recent influx of orthopteran transcriptomic resources, many use
pooled ontogenetic stages obscuring information about changes in gene
expression during development. Here we developed a de novo transcriptome
spanning 7 stages in the life cycle of the acridid grasshopper Chorthippus
biguttulus. Samples from different stages encompassing embryonic development
through adults were used for transcriptomic profiling, revealing patterns of
differential gene expression that highlight processes in the different life
stages. These patterns were validated with semi-quantitative RT-PCR. Embryonic
development showed a strongly differentiated expression pattern compared to
all of the other stages and genes upregulated in this stage were involved in
signaling, cellular differentiation, and organ development. Our study is one
of the first to examine gene expression during post-embryonic development in a
hemimetabolous insect and we found that only the fourth and fifth instars had
clusters of genes upregulated during these stages. These genes are involved in
various processes ranging from synthesis of biogenic amines to chitin binding.
These observations indicate that post-embryonic ontogeny is not a continuous
process and that some instars are differentiated. Finally, genes upregulated
in the imago were generally involved in aging and immunity. Our study
highlights the importance of looking at ontogeny as a whole and indicates
promising directions for future research in orthopteran development
Analysing the Effect of security on information quality dimensions
fails to address the complexity of the case. Our simulation approach incorporates additiona
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