Methodological challenges in evaluating performance, impact and ranking of IWRM strategies in the Jordan Valley

The philosophy of integrated water resource management (IWRM), as formulated in several international summits, yielded numerous interpretations and extensions over the last decade but always focused on the overall objective of maximizing the welfare and livelihood of the people concerned. One of the major constraints of this concept is the gap between the well-defined philosophy and the fuzzy definition of operational and testable indicators for the achievement of its goals. This leads to difficulties in the evaluation of potential contributions from technological and managerial improvements. The experience of the multi-lateral IWRM research initiative SMART in the lower Jordan Valley shows that the evaluation and ranking of alternative IWRM strategies and their elements relies simultaneously on the identification of local goals and their interfaces with the superordinate national water sector policies. The documentation of the, still ongoing, development process of suitable assessment procedures describes their methodological embedding and conclusions drawn for the heterogeneous situation of water-related settings in this transboundary watershed.

Cortical plasticity, contingent negative variation, and transcendent experiences during practice of the Transcendental Meditation technique

This study investigated effects of transcendent experiences on contingent negative variation (CNV) amplitude, CNV rebound, and distraction effects. Three groups of age-matched subjects with few (<1 per year), more frequent (10-20 per year), or daily self-reported transcendent experiences received 31 simple RT trials (flash (S(1))/tone (S(2))/button press) followed by 31 divided-attention trials - randomly intermixed trials with or without a three-letter memory task in the S(1)-S(2) interval). Late CNV amplitudes in the simple trials were smallest in the group with fewest, and largest in the group with most frequent transcendent experiences. Conversely, CNV distraction effects were largest in the group with fewest and smallest in the group with most frequent transcendent experiences (the second group's values were in the middle in each case). These data suggest cumulative effects of transcendent experiences on cortical preparatory response (heightened late CNV amplitude in simple trials) and executive functioning (diminished distraction effects in letter trials).

Unique and multifunctional adhesion junctions in the testis: ectoplasmic specializations

In this paper, we review the structure and function of a unique type of actin-related intercellular adhesion junctions in the testis. Based on their ultrastructure, the junctions are divided into five distinct domains. The currently identified molecular components of each domain are summarized. In addition, the architecture of the mammalian system is compared with that of non-mammalian vertebrates. Functionally, the junctions are related to the turnover of adhesion between Sertoli cells, to the attachment of spermatids to the seminiferous epithelium, and to sperm release. They also are part of the mechanism by which spermatids are moved through the epithelium. Evidence consistent with adhesion and motility related functions is discussed. Control, both of junction turnover and of microtubule-based transport, is identified as an important avenue for future research.

Evidence for a frizzled-mediated wnt pathway required for zebrafish dorsal mesoderm formation

We have used zebrafish as a model system for the study of vertebrate dorsoventral patterning. We isolated a maternally expressed and dorsal organizer localized member of the frizzled family of wnt receptors. Wild-type and dominant, loss-of-function molecules in misexpression studies demonstrate frizzled function is necessary and sufficient for dorsal mesoderm specification. frizzled activity is antagonized by the action of GSK-3, and we show GSK-3 is also required for zebrafish dorsal mesoderm formation. frizzled cooperatively interacts with the maternally encoded zebrafish wnt8 protein in dorsal mesodermal fate determination. This frizzled -mediated wnt pathway for dorsal mesoderm specification provides the first evidence for the requirement of a wnt-like signal in vertebrate axis determination.