Increased Stem Cell Factor Release by Hemangioma-Derived Endothelial Cells

Background: Capillary hemangiomas, the most common tumors in young children, consist of proliferating capillary vessels and endothelial cells. These tumors also contain large numbers of mast cells, compared with the normal surrounding skin or tissue. We have recently shown that stem cell factor (SCF), the gene product of the murine steel locus, can act as a chemoattractant for mast cells. In this study, we investigated whether SCF might be involved in the recruitment and maintenance of mast cells in hemangiomas. Experimental Design: Cultured endothelial cells derived from a murine hemangioma were compared with normal vascular endothelial cells for the ability to produce and release SCF, a mitogen for mast cells. Results: Conditioned medium from hemangioma-derived endothelial cells stimulated the proliferation of cultured mast cells. This proliferative activity was potentiated by interleukin-3. The same conditioned medium was unable to stimulate proliferation of mast cells expressing a defective receptor for SCF. The medium was also unable to stimulate proliferation when it was preincubated with neutralizing antibodies specific for SCF. Immunoprecipitation and Western blot analysis of the conditioned media from hemangioma cells and normal endothelial cells demonstrated the 31,000 molecular weight SCF in hemangioma-conditioned medium only. In addition, proliferative activity for mast cells could not be demonstrated in the conditioned medium of the normal endothelial cells, although Northern blot analysis indicated that both normal and hemangioma-derived endothelial cells express SCF mRNA. Reverse transcriptase-polymerase chain reaction techniques were used to amplify the DNA sequence coding for the proteolytic cleavage site used for release of SCF. Results indicated that both normal and hemangioma-derived endothelial cells express the same transcript for SCF. Conclusions: Our data suggest that increased release of SCF is a property of hemangioma-derived endothelial cells that may account for the high numbers of mast cells observed in hemangioma tissue. This increased release of SCF is not due to alternate splicing of SCF transcripts by hemangioma cells

The Caddisfly Collective: Methods of assessing Trichoptera diversity on a continental scale with community scientists

Amidst a global biodiversity crisis, collecting data at large spatial scales can illuminate patterns. Community science can be an avenue to reduce costs, broaden the scope of sampling, and, most importantly, connect with members of the public who are interested in and impacted by long-term ecological change. In 2021, we formulated a community science project – The Caddisfly Collective. Our goal was to study the regional influences on the responses of stream caddisfly (Trichoptera) communities to urbanization in the United States and Canada. Community scientists helped us achieve this goal by collecting caddisflies across a wider geographic scale than we could have reached on our own. To build The Caddisfly Collective, we recruited participants through social media and other online forums. We mailed collecting kits with a USB-powered ultraviolet LED light, a collecting container, bottles of preservative, data sheets, and collection labels to each participant; participants mailed back specimens and completed data sheets. There was a 79.7% rate of follow-through from sign-up to collection. During the project, 63 participants set up light-traps near urban and non-urban streams in seven different North American geographic regions, collecting adult caddisflies at 141 sites across the United States and Canada. Most sites were in the Midwest region, while the fewest sites were in the Far North region. Urban areas, classified by land cover data, comprised ~29% of total sites. We hope the details of our project can help other interested scientists implement similar projects in the future, especially focused on ecologically important caddisfly communities

Variants in the Mitochondrial Intermediate Peptidase (MIPEP) Gene are Associated with Gray Matter Density in the Alzheimer’s Disease Neuroimaging Initiative Cohort

poster abstractCancer and Alzheimer’s disease (AD) incidence is inversely correlated, but the genetic underpinnings of this relationship remain to be elucidated. Recent findings identified lower gray matter density in frontal regions of participants of the Alzheimer’s Disease Neuroimaging Initiative (ADNI) with cancer history compared to those without such history, across diagnostic groups (Nudelman et al., 2014). Pathways proposed to impact cancer and AD, including metabolism and survival, may play an important role in the observed difference. To test this hypothesis, a genome-wide association study (GWAS) using mean frontal gray matter cluster values was performed for all Caucasian participants in this cohort with neuroimaging and genetic data (n=1405). Analysis covaried for age, sex, AD, and cancer history. Of the two genes with the most significant SNPs (p<10-5), WD repeat domain 5B (WDR5B) and mitochondrial intermediate peptidase (MIPEP), MIPEP was selected for further analysis given the hypothesis focus on metabolism. ANOVA analysis of MIPEP top SNP rs8181878 with frontal gray matter cluster values in SPSS indicated that while this SNP is significantly associated with gray matter density (p=2x10-6), no interaction was observed with cancer history or AD diagnosis. Furthermore, whole brain gray matter voxel-wise analysis of this SNP using Statistical Parametric Mapping 8 software showed that minor allele(s) of this SNP were significantly (PFWE<0.05) associated with higher gray matter density. These results suggest that the minor allele of MIPEP SNP rs8181878 may be protective against gray matter density loss, highlighting the importance of metabolic processes in aging and disease

Plasticity of face processing in infancy

Experience plays a crucial role for the normal development of many perceptual and cognitive functions, such as speech perception. For example, between 6 and 10 months of age, the infant's ability to discriminate among native speech sounds improves, whereas the ability to discriminate among foreign speech sounds declines. However, a recent investigation suggests that some experience with nonnative languages from 9 months of age facilitates the maintenance of this ability at 12 months. Nelson has suggested that the systems underlying face processing may be similarly sculpted by experience with different kinds of faces. In the current investigation, we demonstrate that, in human infants between 6 and 9 months of age, exposure to nonnative faces, in this case, faces of Barbary macaques (Macaca sylvanus), facilitates the discrimination of monkey faces, an ability that is otherwise lost around 9 months of age. These data support, and further elucidate, the role of early experience in the development of face processing

Association of cancer history with Alzheimer's disease onset and structural brain changes

Epidemiological studies show a reciprocal inverse association between cancer and Alzheimer's disease (AD). The common mechanistic theory for this effect posits that cells have an innate tendency toward apoptotic or survival pathways, translating to increased risk for either neurodegeneration or cancer. However, it has been shown that cancer patients experience cognitive dysfunction pre- and post-treatment as well as alterations in cerebral gray matter density (GMD) on MRI. To further investigate these issues, we analyzed the association between cancer history (CA±) and age of AD onset, and the relationship between GMD and CA± status across diagnostic groups in the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort study. Data was analyzed from 1609 participants with information on baseline cancer history and AD diagnosis, age of AD onset, and baseline MRI scans. Participants were CA+ (N = 503) and CA− (N = 1106) diagnosed with AD, mild cognitive impairment (MCI), significant memory concerns (SMC), and cognitively normal older adults. As in previous studies, CA+ was inversely associated with AD at baseline (P = 0.025); interestingly, this effect appears to be driven by non-melanoma skin cancer (NMSC), the largest cancer category in this study (P = 0.001). CA+ was also associated with later age of AD onset (P < 0.001), independent of apolipoprotein E (APOE) ε4 allele status, and individuals with two prior cancers had later mean age of AD onset than those with one or no prior cancer (P < 0.001), suggesting an additive effect. Voxel-based morphometric analysis of GMD showed CA+ had lower GMD in the right superior frontal gyrus compared to CA− across diagnostic groups (Pcrit < 0.001, uncorrected); this cluster of lower GMD appeared to be driven by history of invasive cancer types, rather than skin cancer. Thus, while cancer history is associated with a measurable delay in AD onset independent of APOE ε4, the underlying mechanism does not appear to be cancer-related preservation of GMD

Exile Vol. XXXVI No. 1

untitled by Nichola Gracille (Cover) Words by Kent Lambert 1 Talk by Richard Latimer 2 Storm Passing by Ben Kell 3 untitled by Ed Stanley 4 I Again Awake by Sharnon Salser 5-6 Demigods and Demons by Kent Lambert 7 untitled by Tim Loving 8 Apology by Kelly Bondurant 9-10 Guest Speaker by Ann Mierson 11 untitled by Nicalas Gracilla 12 Watching for Minnows by Kent Lambert 13 Thunderbird by Kelly Bondurant 14-16 Glendalough (St. Kevin) by Ben Kell 17-18 Untitled by Craig Bagno 19 Flying Machines In Pieces On The Ground by Kelly Bondurant 20 Tuesday, December 13, 1988 Bill & Walt\u27s Toy Shoppe by Alexander Speyer 21 Weathered Wood by Kelly Bondurant 22 Above Grey Water by Susanna Duff 23-25 untitled by Ed Stanley 26 Contributor\u27s Notes 27 Editorial decision is shared equally among the Editorial Board -

Information Symmetries in Irreversible Processes

We study dynamical reversibility in stationary stochastic processes from an information theoretic perspective. Extending earlier work on the reversibility of Markov chains, we focus on finitary processes with arbitrarily long conditional correlations. In particular, we examine stationary processes represented or generated by edge-emitting, finite-state hidden Markov models. Surprisingly, we find pervasive temporal asymmetries in the statistics of such stationary processes with the consequence that the computational resources necessary to generate a process in the forward and reverse temporal directions are generally not the same. In fact, an exhaustive survey indicates that most stationary processes are irreversible. We study the ensuing relations between model topology in different representations, the process's statistical properties, and its reversibility in detail. A process's temporal asymmetry is efficiently captured using two canonical unifilar representations of the generating model, the forward-time and reverse-time epsilon-machines. We analyze example irreversible processes whose epsilon-machine presentations change size under time reversal, including one which has a finite number of recurrent causal states in one direction, but an infinite number in the opposite. From the forward-time and reverse-time epsilon-machines, we are able to construct a symmetrized, but nonunifilar, generator of a process---the bidirectional machine. Using the bidirectional machine, we show how to directly calculate a process's fundamental information properties, many of which are otherwise only poorly approximated via process samples. The tools we introduce and the insights we offer provide a better understanding of the many facets of reversibility and irreversibility in stochastic processes.Comment: 32 pages, 17 figures, 2 tables; http://csc.ucdavis.edu/~cmg/compmech/pubs/pratisp2.ht

Alteration of Microbial Communities Colonizing Leaf Litter in a Temperate Woodland Stream by Growth of Trees Under Conditions of Elevated Atmospheric CO\u3csub\u3e2\u3c/sub\u3e

Elevated atmospheric CO2 can cause increased carbon fixation and altered foliar chemical composition in a variety of plants, which has the potential to impact forested headwater streams because they are detritus-based ecosystems that rely on leaf litter as their primary source of organic carbon. Fungi and bacteria play key roles in the entry of terrestrial carbon into aquatic food webs, as they decompose leaf litter and serve as a source of nutrition for invertebrate consumers. This study tested the hypothesis that changes in leaf chemistry caused by elevated atmospheric CO2 would result in changes in the size and composition of microbial communities colonizing leaves in a woodland stream. Three tree species, Populus tremuloides, Salix alba, and Acer saccharum, were grown under ambient (360 ppm) or elevated (720 ppm) CO2, and their leaves were incubated in a woodland stream. Elevated-CO2 treatment resulted in significant increases in the phenolic and tannin contents and C/N ratios of leaves. Microbial effects, which occurred only for P. tremuloides leaves, included decreased fungal biomass and decreased bacterial counts. Analysis of fungal and bacterial communities on P. tremuloides leaves via terminal restriction fragment length polymorphism (T-RFLP) and clone library sequencing revealed that fungal community composition was mostly unchanged by the elevated-CO2 treatment, whereas bacterial communities showed a significant shift in composition and a significant increase in diversity. Specific changes in bacterial communities included increased numbers of alphaproteobacterial and cytophaga-flavobacter-bacteroides (CFB) group sequences and decreased numbers of betaproteobacterial and firmicutes sequences, as well as a pronounced decrease in overall Gram-positive bacterial sequences

The Value of Information for Populations in Varying Environments

The notion of information pervades informal descriptions of biological systems, but formal treatments face the problem of defining a quantitative measure of information rooted in a concept of fitness, which is itself an elusive notion. Here, we present a model of population dynamics where this problem is amenable to a mathematical analysis. In the limit where any information about future environmental variations is common to the members of the population, our model is equivalent to known models of financial investment. In this case, the population can be interpreted as a portfolio of financial assets and previous analyses have shown that a key quantity of Shannon's communication theory, the mutual information, sets a fundamental limit on the value of information. We show that this bound can be violated when accounting for features that are irrelevant in finance but inherent to biological systems, such as the stochasticity present at the individual level. This leads us to generalize the measures of uncertainty and information usually encountered in information theory