A Comparison of Two Methods of Quantifying Mating Success in Low Density Gypsy Moth (Lymantria dispar) Populations

The gypsy moth (Lymantria dispar) is a defoliating pest native to Europe and invasive to North America. The gypsy moth is subject to depressed mating success in low density populations, which may restrict spread of the forest pest. Research focusing on gypsy moth density as it relates to mating behavior has often used counts of males caught in pheromone-baited delta traps as a proxy to estimate the probability of female mating success. The purpose of this project was to determine whether pheromone trap counts provide accurate estimates of female mating success probability, by comparing data gathered from pheromone-baited delta traps to data gathered on mating success of tethered females. To determine the relationship between number of males caught in delta traps and the probability of successful mating, male catch counts in traps were compared to mating success of tethered females in a mass male release experiment. The relationship between delta trap catch of males and female mating success was quantified using a Bayesian framework, which explicitly incorporates uncertainties in the model. Vegetative cover in the study plots was reduced to a single measure through principal components analysis and included as an independent factor in the model. The data suggest that delta traps reduce the male’s ability to find a female by 67%; thus, results garnered from delta trap catch counts tend to underestimate the underlying ability of males to locate and mate with females. Thick understory vegetation further reduced the male’s ability to locate a female, and further reduced the effectiveness of delta traps. Future studies that seek to use counts of males in pheromone-baited traps as a proxy for mating success should consider using an adjustment factor to equate the two methods of quantifying reproductive behavior in the gypsy moth.https://scholarscompass.vcu.edu/uresposters/1271/thumbnail.jp

Maidens in Maizes: Johnson, Grimms, d\u27Aulnoy

Senior Project submitted to The Division of Languages and Literature of Bard College. A German Studies and Written Arts joint project, with a collection of original fairy tales as well as an in-depth analysis of female agency, female mutilation, religious influence, and language within the fairy tales of Grimms and Madame d\u27Aulnoy

Toward quantitative phosphotyrosine profiling in vivo

Tyrosine phosphorylation is a dynamic reversible post-translational modification that regulates many aspects of cell biology. To understand how this modification controls biological function, it is necessary to not only identify the specific sites of phosphorylation, but also to quantify how phosphorylation levels on these sites may be altered under specific physiological conditions. Due to its sensitivity and accuracy, mass spectrometry (MS) has widely been applied to the identification and characterization of phosphotyrosine signaling across biological systems. In this review we highlight the advances in both MS and phosphotyrosine enrichment methods that have been developed to enable the identification of low level tyrosine phosphorylation events. Computational and manual approaches to ensure confident identification of phosphopeptide sequence and determination of phosphorylation site localization are discussed along with methods that have been applied to the relative quantification of large numbers of phosphorylation sites. Finally, we provide an overview of the challenges ahead as we extend these technologies to the characterization of tyrosine phosphorylation signaling in vivo. With these latest developments in analytical and computational techniques, it is now possible to derive biological insight from quantitative MS-based analysis of signaling networks in vitro and in vivo. Application of these approaches to a wide variety of biological systems will define how signal transduction regulates cellular physiology in health and disease

Quantitative Analysis of Signaling Networks across Differentially Embedded Tumors Highlights Interpatient Heterogeneity in Human Glioblastoma

Glioblastoma multiforme (GBM) is the most aggressive malignant primary brain tumor, with a dismal mean survival even with the current standard of care. Although in vitro cell systems can provide mechanistic insight into the regulatory networks governing GBM cell proliferation and migration, clinical samples provide a more physiologically relevant view of oncogenic signaling networks. However, clinical samples are not widely available and may be embedded for histopathologic analysis. With the goal of accurately identifying activated signaling networks in GBM tumor samples, we investigated the impact of embedding in optimal cutting temperature (OCT) compound followed by flash freezing in LN[subscript 2] vs immediate flash freezing (iFF) in LN[subscript 2] on protein expression and phosphorylation-mediated signaling networks. Quantitative proteomic and phosphoproteomic analysis of 8 pairs of tumor specimens revealed minimal impact of the different sample processing strategies and highlighted the large interpatient heterogeneity present in these tumors. Correlation analyses of the differentially processed tumor sections identified activated signaling networks present in selected tumors and revealed the differential expression of transcription, translation, and degradation associated proteins. This study demonstrates the capability of quantitative mass spectrometry for identification of in vivo oncogenic signaling networks from human tumor specimens that were either OCT-embedded or immediately flash-frozen.James S. McDonnell FoundationUnited States-Israel Binational Science FoundationNational Institutes of Health (U.S.) (Grant U54 CA112967)National Institutes of Health (U.S.) (Grant U24 CA159988

Robust High-Dynamic-Range Vector Magnetometry via Nitrogen-Vacancy Centers in Diamond

We demonstrate a robust, scale-factor-free vector magnetometer, which uses a closed-loop frequency-locking scheme to simultaneously track Zeeman-split resonance pairs of nitrogen-vacancy (NV) centers in diamond. Compared with open-loop methodologies, this technique is robust against fluctuations in temperature, resonance linewidth, and contrast; offers a three-order-of-magnitude increase in dynamic range; and allows for simultaneous interrogation of multiple transition frequencies. By directly detecting the resonance frequencies of NV centers aligned along each of the diamond's four tetrahedral crystallographic axes, we perform full vector reconstruction of an applied magnetic field

Long-range orbitofrontal and amygdala axons show divergent patterns of maturation in the frontal cortex across adolescence.

The adolescent transition from juvenile to adult is marked by anatomical and functional remodeling of brain networks. Currently, the cellular and synaptic level changes underlying the adolescent transition are only coarsely understood. Here, we use two-photon imaging to make time-lapse observations of long-range axons that innervate the frontal cortex in the living brain. We labeled cells in the orbitofrontal cortex (OFC) and basolateral amygdala (BLA) and imaged their axonal afferents to the dorsomedial prefrontal cortex (dmPFC). We also imaged the apical dendrites of dmPFC pyramidal neurons. Images were taken daily in separate cohorts of juvenile (P24-P28) and young adult mice (P64-P68), ages where we have previously discovered differences in dmPFC dependent decision-making. Dendritic spines were pruned across this peri-adolescent period, while BLA and OFC afferents followed alternate developmental trajectories. OFC boutons showed no decrease in density, but did show a decrease in daily bouton gain and loss with age. BLA axons showed an increase in both bouton density and daily bouton gain at the later age, suggesting a delayed window of enhanced plasticity. Our findings reveal projection specific maturation of synaptic structures within a single frontal region and suggest that stabilization is a more general characteristic of maturation than pruning

Further generalization of symmetric multiplicity theory to the geometric case over a field

0751964. Further, this work was carried out within the activities of CMA/FCT/UNL and it was partially supported by the Fundacao para a Ciencia e a Tecnologia (Portuguese Foundation for Science and Technology) through the project UIDB/00297/2020.Using the recent geometric Parter-Wiener, etc. theorem and related results, it is shown that much of the multiplicity theory developed for real symmetric matrices associated with paths and generalized stars remains valid for combinatorially symmetric matrices over a field. A characterization of generalized stars in the case of combinatorially symmetric matrices is given.publishersversionpublishe

Does adaptation to high altitude affect hypoxia-dependent structural plasticity of the placenta?

High altitude residence causes fetal growth restriction (FGR) during pregnancy in lowland mammals. Highland-adapted mammals do not experience this altitude-dependent FGR, suggesting that adaptation to altitude has produced some protective mechanisms. However, the specific mechanisms by which highland-adapted mammals preserve fetal growth at altitude remain unknown. We hypothesized that highland-adapted populations protect fetal growth through structural changes to the placenta that increase surface area for nutrient and gas exchange. We tested this hypothesis using deer mice (Peromyscus maniculatus), from populations native to low [400 m, Lincoln, NE] and high [4300 m, Mt. Evans, CO] altitudes. We predicted structural adaptation would occur via increases to the relative size of the labyrinth zone (LZ), the layer within the rodent placenta where nutrient and gas exchange occur. Placentas were collected from lowland and highland deer mice undergoing pregnancy under normoxia or hypoxia (60 kPa) to understand how hypoxia-dependent structural plasticity might interact with adaptive remodeling of the placenta (N = 5-7 per strain and treatment). Using immunohistochemistry, we quantified the size of each placenta zone. Our preliminary results show that highlanders have relatively larger placental arteries and LZs under both normoxia and hypoxia (P \u3c 0.05 in generalized linear mixed model), suggesting that blood delivery and area for exchange (as determined by the LZ size) may protect fetal growth in highlanders. Future work will pair histological characterization of placental structure with transcriptomics to guide a mechanistic understanding of how placentation constrains to fetal growth under hypoxia

Qualitatively Different T Cell Phenotypic Responses to IL-2 versus IL-15 Are Unified by Identical Dependences on Receptor Signal Strength and Duration

IL-2 and IL-15 are common γ-chain family cytokines involved in regulation of T cell differentiation and homeostasis. Despite signaling through the same receptors, IL-2 and IL-15 have non-redundant roles in T cell biology, both physiologically and at the cellular level. The mechanisms by which IL-2 and IL-15 trigger distinct phenotypes in T cells remain elusive. To elucidate these mechanisms, we performed a quantitative comparison of the phosphotyrosine signaling network and resulting phenotypes triggered by IL-2 and IL-15. This study revealed that the signaling networks activated by IL-2 or IL-15 are highly similar and that T cell proliferation and metabolism are controlled in a quantitatively distinct manner through IL-2/15R signal strength independent of the cytokine identity. Distinct phenotypes associated with IL-2 or IL-15 stimulation therefore arise through differential regulation of IL-2/15R signal strength and duration because of differences in cytokine–receptor binding affinity, receptor expression levels, physiological cytokine levels, and cytokine–receptor intracellular trafficking kinetics. These results provide important insights into the function of other shared cytokine and growth factor receptors, quantitative regulation of cell proliferation and metabolism through signal transduction, and improved design of cytokine based clinical immunomodulatory therapies for cancer and infectious diseases.National Institutes of Health (U.S.) (Grant U54CA11927)National Institutes of Health (U.S.) (Grant R01 AI065824)United States. Army Research Office (Institute for Collaborative Biotechnologies Grant W911NF-09-0001

Computer aided manual validation of mass spectrometry-based proteomic data

Advances in mass spectrometry-based proteomic technologies have increased the speed of analysis and the depth provided by a single analysis. Computational tools to evaluate the accuracy of peptide identifications from these high-throughput analyses have not kept pace with technological advances; currently the most common quality evaluation methods are based on statistical analysis of the likelihood of false positive identifications in large-scale data sets. While helpful, these calculations do not consider the accuracy of each identification, thus creating a precarious situation for biologists relying on the data to inform experimental design. Manual validation is the gold standard approach to confirm accuracy of database identifications, but is extremely time-intensive. To palliate the increasing time required to manually validate large proteomic datasets, we provide computer aided manual validation software (CAMV) to expedite the process. Relevant spectra are collected, catalogued, and pre-labeled, allowing users to efficiently judge the quality of each identification and summarize applicable quantitative information. CAMV significantly reduces the burden associated with manual validation and will hopefully encourage broader adoption of manual validation in mass spectrometry-based proteomics.National Institutes of Health (U.S.) (Grant R24DK090963)National Institutes of Health (U.S.) (Grant U54CA112967)National Cancer Institute (U.S.). Integrative Cancer Biology Program (Fellowship)Charles S. Krakauer FellowshipHugh Hampton Young Fellowshi