Identification of a component of Drosophila polar granules

Information necessary for the formation of pole cells, precursors of the germ line, is provided maternally and localized to the posterior pole of the Drosophila egg. The maternal origin and posterior localization of polar granules suggest that they may be associated with pole cell determinants. We have generated an antibody (Mab46F11) against polar granules. In oocytes and early embryos, the Mab46F11 antigen is sharply localized to the posterior embryonic pole. In pole cells, it becomes associated with nuclear bodies within, and nuage around, the nucleus. Immunoreactivity remains associated with cells of the germ line throughout the life cycle of both males and females. This antibody recognizes a 72-74 X 10^(3) Mr protein and is useful both as a pole lineage marker and in biochemical studies of polar granules

Sources Of Income Inequality Among the Elderly

Sources of inequality among American households with a retired elderly head were examined by decomposition of Gini coefficients. Inequality of investment and labor income contributed most to overall income inequality. Income inequality of three types of households couples with one retiree, retired couples, and retired singles were studied in terms of sources of income inequality. Inequality of investment income contributed most to income inequality for retired singles and for retired couples

R&D on an Ultra-Thin Composite Membrane for High-Temperature Operation in PEMFC. Final Report

FuelCell Energy developed a novel high-temperature proton exchange membrane for PEM fuel cells for building applications. The laboratory PEM fuel cell successfully operated at 100-400{supdegree}C and low relative humidity to improve CO tolerance, mitigate water and thermal management challenges, and reduce membrane cost. The developed high-temperature membrane has successfully completed 500h 120C endurance testing

An Enhanced Nonlinear Critical Gradient for Electron Turbulent Transport due to Reversed Magnetic Shear

The first nonlinear gyrokinetic simulations of electron internal transport barriers (e-ITBs) in the National Spherical Torus Experiment show that reversed magnetic shear can suppress thermal transport by increasing the nonlinear critical gradient for electron-temperature-gradient-driven turbulence to three times its linear critical value. An interesting feature of this turbulence is nonlinearly driven off-midplane radial streamers. This work reinforces the experimental observation that magnetic shear is likely an effective way of triggering and sustaining e-ITBs in magnetic fusion devices.Comment: 4 pages, 5 figure

An Enhanced Nonlinear Critical Gradient for Electron Turbulent Transport due to Reversed Magnetic Shear

The first nonlinear gyrokinetic simulations of electron internal transport barriers (e-ITBs) in the National Spherical Torus Experiment show that reversed magnetic shear can suppress thermal transport by increasing the nonlinear critical gradient for electron-temperature-gradient-driven turbulence to three times its linear critical value. An interesting feature of this turbulence is nonlinearly driven off-midplane radial streamers. This work reinforces the experimental observation that magnetic shear is likely an effective way of triggering and sustaining e-ITBs in magnetic fusion devices.Comment: 4 pages, 5 figure

Human parathyroid hormone fragment stimulates the de novo synthesis of prostaglandin endoperoxide synthase in chick calvaria

The human parathyroid hormone N-terminal fragment [hPTH-(1–34)] increases the conversion of exogenous unsaturated fatty acids to prostaglandins (PGs) in calvarial homogenates. Enzyme activities were completely blocked by indomethacin (5 × 10−7 M), a PG synthase inhibitor, and actinomycin D (5 μM), an inhibitor of transcription, by binding to DNA. In addition, a potent inhibitor of protein synthesis, cycloheximide (10 μM), totally inhibited the stimulating effect of hPTH-(1–34) on prostaglandin endoperoxide synthase (PG synthase, EC 1.14.99.1). The stimulatory effect of hPTH-(1–34) on PG synthase was also reduced by the addition of stannous chloride. However, epidermal growth factor (EGF), platelet-derived activating factor (PDGF), and ionophore A23187 did not show the same stimulating effect as hPTH-(1–34) on PG synthase in calvaria. The results further demonstrated that PG synthase is a membrane-bound enzyme in chick calvaria. In this communication, evidence is presented that hPTH-(1–34) stimulates the de novo synthesis of PG synthase as demonstrated by the increased activity in calvarial homogenates and microsomes

Federated Learning for Sparse Principal Component Analysis

In the rapidly evolving realm of machine learning, algorithm effectiveness often faces limitations due to data quality and availability. Traditional approaches grapple with data sharing due to legal and privacy concerns. The federated learning framework addresses this challenge. Federated learning is a decentralized approach where model training occurs on client sides, preserving privacy by keeping data localized. Instead of sending raw data to a central server, only model updates are exchanged, enhancing data security. We apply this framework to Sparse Principal Component Analysis (SPCA) in this work. SPCA aims to attain sparse component loadings while maximizing data variance for improved interpretability. Beside the L1 norm regularization term in conventional SPCA, we add a smoothing function to facilitate gradient-based optimization methods. Moreover, in order to improve computational efficiency, we introduce a least squares approximation to original SPCA. This enables analytic solutions on the optimization processes, leading to substantial computational improvements. Within the federated framework, we formulate SPCA as a consensus optimization problem, which can be solved using the Alternating Direction Method of Multipliers (ADMM). Our extensive experiments involve both IID and non-IID random features across various data owners. Results on synthetic and public datasets affirm the efficacy of our federated SPCA approach.Comment: 11 pages, 7 figures, 1 table. Accepted by IEEE BigData 2023, Sorrento, Ital

Identification of E2/E3 Ubiquitinating Enzymes and Caspase Activity Regulating Drosophila Sensory Neuron Dendrite Pruning

SummaryUbiquitin-proteasome system (UPS) is a multistep protein degradation machinery implicated in many diseases. In the nervous system, UPS regulates remodeling and degradation of neuronal processes and is linked to Wallerian axonal degeneration, though the ubiquitin ligases that confer substrate specificity remain unknown. Having shown previously that class IV dendritic arborization (C4da) sensory neurons in Drosophila undergo UPS-mediated dendritic pruning during metamorphosis, we conducted an E2/E3 ubiquitinating enzyme mutant screen, revealing that mutation in ubcD1, an E2 ubiquitin-conjugating enzyme, resulted in retention of C4da neuron dendrites during metamorphosis. Further, we found that UPS activation likely leads to UbcD1-mediated degradation of DIAP1, a caspase-antagonizing E3 ligase. This allows for local activation of the Dronc caspase, thereby preserving C4da neurons while severing their dendrites. Thus, in addition to uncovering E2/E3 ubiquitinating enzymes for dendrite pruning, this study provides a mechanistic link between UPS and the apoptotic machinery in regulating neuronal process remodeling

Performance evaluation of distributed systems with unbalanced flows : an analysis of the INFOPLEX data storage hierarchy

Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, 1985.MICROFICHE COPY AVAILABLE IN ARCHIVES AND DEWEY.Bibliography: leaves 165-171.by Yng-Yuh Richard Wang.Ph.D

Excitonic BCS-BEC crossover at finite temperature: Effects of repulsion and electron-hole mass difference

The BCS to Bose-Einstein condensation (BEC) crossover of electron-hole (e-h) pairs in optically excited semiconductors is studied using the two-band Hubbard model with both repulsive and attractive interactions. Applying the self-consistent t-matrix approximation combined with a local approximation, we examine the properties of a normal phase and an excitonic instability. The transition temperature from the normal phase to an e-h pair condensed one is studied to clarify the crossover from an e-h BCS-like state to an excitonic Bose-Einstein condensation, which takes place on increasing the e-h attraction strength. To investigate effects of the repulsive interaction and the e-h mass difference, we calculate the transition temperature for various parameters of the interaction strengths, the e-h particle density, and the mass difference. While the transition temperature in the e-h BCS regime is sufficiently suppressed by the repulsive interaction, that of the excitonic BEC is largely insensitive to it. We also show quantitatively that in the whole regime the mass difference leads to large suppression of the transition temperature.Comment: 8 pages, 7 figures, to be published in Phys. Rev.