Glycans and glycosaminoglycans in neurobiology: key regulators of neuronal cell function and fate

The aim of the present study was to examine the roles of l-fucose and the glycosaminoglycans (GAGs) keratan sulfate (KS) and chondroitin sulfate/dermatan sulfate (CS/DS) with selected functional molecules in neural tissues. Cell surface glycans and GAGs have evolved over millions of years to become cellular mediators which regulate fundamental aspects of cellular survival. The glycocalyx, which surrounds all cells, actuates responses to growth factors, cytokines and morphogens at the cellular boundary, silencing or activating downstream signaling pathways and gene expression. In this review, we have focused on interactions mediated by l-fucose, KS and CS/DS in the central and peripheral nervous systems. Fucose makes critical contributions in the area of molecular recognition and information transfer in the blood group substances, cytotoxic immunoglobulins, cell fate-mediated Notch-1 interactions, regulation of selectin-mediated neutrophil extravasation in innate immunity and CD-34-mediated new blood vessel development, and the targeting of neuroprogenitor cells to damaged neural tissue. Fucosylated glycoproteins regulate delivery of synaptic neurotransmitters and neural function. Neural KS proteoglycans (PGs) were examined in terms of cellular regulation and their interactive properties with neuroregulatory molecules. The paradoxical properties of CS/DS isomers decorating matrix and transmembrane PGs and the positive and negative regulatory cues they provide to neurons are also discussed

Spatial Clustering and Ecological Crowding of Valley Oak (Quercus lobata, Née) Associated with Shifts in Recruitment Establishment Sites in Southern California

Premise of research. Valley oak (Quercus lobata, Née) has received much attention due to concerns about regeneration failure and, more recently, compositional and structural community changes associated with this foundation species. Changes in the structure and spatial distribution of valley oak stands, as examined in this article, are likely affecting ecological processes and interactions throughout communities where it is found. Methodology. We used quadrat-based methods of spatial analysis, Morisita’s index of aggregation (IM), and a derived index (IMr ) to examine patterns of clustering, intensity of crowding, and changes in the probability of crowding as the definition of crowding (stems/area) is changed. Saplings, defined as stems with a diameter at breast height (dbh) greater than 1 cm and less than 10 cm (1 cm ≤ dbh ! 10 cm) and adults (dbh ≥ 10 cm) were analyzed using four quadrat sizes. We mapped clusters of stems on the basis of spatial autocorrelation of dbh using Anselin’s local Moran’s I to identify the location of sapling and adult stem clusters. Pivotal results. Adults and saplings were clustered for all quadrat sizes, although the intensity of clustering and crowding differed among sites. Two sites had much higher intensity of clustering and crowding, and saplings were spatially segregated from adults away from open savannah habitat. At a third site, stems were less intensely clustered, and saplings did not show clustering away from adults. The intensity of sapling crowding differed among sites as the definition of crowding changed, revealing that saplings experience greater levels of crowding at two of the sites than at the third. Conclusions. Valley oak regeneration is spatially aggregated and ecologically crowded, indicating a shift to higher-density riparian woodland and increasingly open grassland seen at other sites and in other studies. Land change is an important driver of spatial regeneration patterns and may be playing a role here, although additional work is needed to examine the effects of possible drivers of crowding and the habitat shift. Future work should consider the ecological implications of structural and spatial changes in valley oak stands for associated species and processes

Immunolocalization of keratan sulfate in rat spinal tissues using the keratanase generated BKS-1(+) neoepitope: correlation of expression patterns with the slass II SLRPs, lumican and keratocan

This study has identified keratan sulfate in fetal and adult rat spinal cord and vertebral connective tissues using the antibody BKS-1(+) which recognizes a reducing terminal N-acetyl glucosamine-6-sulfate neo-epitope exposed by keratanase-I digestion. Labeling patterns were correlated with those of lumican and keratocan using core protein antibodies to these small leucine rich proteoglycan species. BKS-1(+) was not immunolocalized in fetal spinal cord but was apparent in adult cord and was also prominently immunolocalized to the nucleus pulposus and inner annulus fibrosus of the intervertebral disc. Interestingly, BKS-1(+) was also strongly associated with vertebral body ossification centers of the fetal spine. Immunolocalization of lumican and keratocan was faint within the vertebral body rudiments of the fetus and did not correlate with the BKS-1(+) localization indicating that this reactivity was due to another KS-proteoglycan, possibly osteoadherin (osteomodulin) which has known roles in endochondral ossification. Western blotting of adult rat spinal cord and intervertebral discs to identify proteoglycan core protein species decorated with the BKS-1(+) motif confirmed the identity of 37 and 51 kDa BKS-1(+) positive core protein species. Lumican and keratocan contain low sulfation KS-I glycoforms which have neuroregulatory and matrix organizational properties through their growth factor and morphogen interactive profiles and ability to influence neural cell migration. Furthermore, KS has interactive capability with a diverse range of neuroregulatory proteins that promote neural proliferation and direct neural pathway development, illustrating key roles for keratocan and lumican in spinal cord development

A Resilience-Based Approach to the Conservation of Valley Oak in a Southern California Landscape

Conservation thinking will benefit from the incorporation of a resilience perspective of landscapes as social-ecological systems that are continually changing due to both internal dynamics and in response to external factors such as a changing climate. The examination of two valley oak stands in Southern California provides an example of the necessity of this systems perspective where each stand is responding differently as a result of interactions with other parts of the landscape. One stand is experiencing regeneration failure similar to other stands across the state, and is exhibiting shifts in spatial pattern as a response to changing conditions. A nearby stand is regenerating well and maintaining spatial and structural patterns, likely due to the availability of imported water associated with upstream urban development. Valley oak stands have a capacity for reorganization as a response to changes in the landscape and environmental conditions. This reorganization can benefit conservation efforts; however, we must ask what limits there are to valley oak’s capacity to reorganize and still maintain its ecological function in face of increasing changes in climate and land cover. The usefulness of resilience as a concept in conservation is discussed at several scales from the stand to the landscape

Should you reassess your patient's asthma diagnosis?

Review of: Aaron SD, Vandemheen KL, FitzGerald JM, et al. Reevaluation of diagnosis in adults with physician-diagnosed asthma. JAMA. 2017;317: 269-279.Should you reassess your patient's asthma diagnosis? Asthma may not be a permanent diagnosis in adults. A study finds that up to one-third of adults with physician-diagnosed asthma no longer had it after 5 years. Practice-changer: Consider tapering medications and retesting spirometry in adults with well-controlled asthma, as many may no longer have the disease. Stength of recommendation: A: Based on a high-quality prospective cohort study and consistent findings in other studies.James J. Stevermer MD, MSPH; Alisa Hayes, MD (Department of Family and Community Medicine (Dr. Stevermer) and Department of Emergency Medicine (Dr. Hayes), University of Missouri-Columbia

VALUING AMBIGUITY: THE CASE OF GENETICALLY ENGINEERED GROWTH ENHANCERS

A split-valuation method is developed and implemented to elicit the willingness to pay to consume- or avoid consuming- a product of ambiguous quality. The split-valuation method uses experimental auction markets to separate and value the positive and negative attributes of the ambiguous good. The results show that the method can be used to successfully value a good ambiguous quality. Our application reveals that for a sample of students at a midwestern land-grant institution, the average respondent is willing to pay a premium for meat produced with the use of a genetically engineered growth enhancer that has 30% to 60% fewer calories and is 10% to 20% leaner.Consumer/Household Economics,

EXPERIMENTAL METHODS IN CONSUMER PREFERENCE STUDIES

Controlled experimental auctions can be used to elicit preferences for food products. We describe results from two series of experiments in which subjects revealed their willingness-to-pay for safer food. In one series, the risk reduction technology was not specified; in the other, it was identified as food irradiation. The results provide some evidence on the acceptability of food irradiation as a risk reduction technology.Consumer/Household Economics,