750 GeV Resonance in the Gauged U(1)′U(1)'-Extended MSSM

Recently the ATLAS and CMS collaborations at the LHC announced their observation of a potential 750 GeV di-photon resonance, after analyzing the $\sqrt{s}=13$ TeV LHC data. This observation has significant implications for low-energy supersymmetry. Beyond the MSSM and the NMSSM, we study the MSSM-extensions with an extra $U(1)'$ gauge symmetry. The anomaly cancellation and the spontaneous breaking of the non-decoupled $U(1)'$ generically require introducing vector-like supermultiplets (both colored and color-neutral ones) and singlet supermultiplets, respectively. We illustrate that the potential 750 GeV resonance ($Y$) can be accommodated in various mechanisms, as a singlet-like scalar or pseudoscalar. Three benchmark scenarios are presented: (1) vector-like quarks (VLQ) mediated $pp \to Y \to \gamma \gamma$; (2) scalar VLQ mediated $pp \to Y \to \gamma \gamma$; (3) heavy scalar (pseudo-scalar) $H/A$ associated production $pp \to H^*/A^* \to Y H/h$. Additionally, we notice that the $Z'$-mediated vector boson fusion production and $Z'$-associated production $pp \to Y qq'$, if yielding a signal rate of the observed level, might have been excluded by the searches for $Z'$ via Drell-Yan process at the LHC.Comment: v3, figure update with corresponding modification in discussion, version accepted by PL

Postsynaptic protein organization revealed by electron microscopy.

Neuronal synapses are key devices for transmitting and processing information in the nervous system. Synaptic plasticity, generally regarded as the cellular basis of learning and memory, involves changes of subcellular structures that take place at the nanoscale. High-resolution imaging methods, especially electron microscopy (EM), have allowed for quantitative analysis of such nanoscale structures in different types of synapses. In particular, the semi-ordered organization of neurotransmitter receptors and their interacting scaffolds in the postsynaptic density have been characterized for both excitatory and inhibitory synapses by studies using various EM techniques such as immuno-EM, electron tomography of high-pressure freezing and freeze-substituted samples, and cryo electron tomography. These techniques, in combination with new correlative approaches, will further facilitate our understanding of the molecular organization underlying diverse functions of neuronal synapses

Accumulation of Dense Core Vesicles in Hippocampal Synapses Following Chronic Inactivity.

The morphology and function of neuronal synapses are regulated by neural activity, as manifested in activity-dependent synapse maturation and various forms of synaptic plasticity. Here we employed cryo-electron tomography (cryo-ET) to visualize synaptic ultrastructure in cultured hippocampal neurons and investigated changes in subcellular features in response to chronic inactivity, a paradigm often used for the induction of homeostatic synaptic plasticity. We observed a more than 2-fold increase in the mean number of dense core vesicles (DCVs) in the presynaptic compartment of excitatory synapses and an almost 20-fold increase in the number of DCVs in the presynaptic compartment of inhibitory synapses after 2 days treatment with the voltage-gated sodium channel blocker tetrodotoxin (TTX). Short-term treatment with TTX and the N-methyl-D-aspartate receptor (NMDAR) antagonist amino-5-phosphonovaleric acid (AP5) caused a 3-fold increase in the number of DCVs within 100 nm of the active zone area in excitatory synapses but had no significant effects on the overall number of DCVs. In contrast, there were very few DCVs in the postsynaptic compartments of both synapse types under all conditions. These results are consistent with a role for presynaptic DCVs in activity-dependent synapse maturation. We speculate that these accumulated DCVs can be released upon reactivation and may contribute to homeostatic metaplasticity

Cryo-EM structures of herpes simplex virus type 1 portal vertex and packaged genome.

Herpesviruses are enveloped viruses that are prevalent in the human population and are responsible for diverse pathologies, including cold sores, birth defects and cancers. They are characterized by a highly pressurized pseudo-icosahedral capsid-with triangulation number (T) equal to 16-encapsidating a tightly packed double-stranded DNA (dsDNA) genome1-3. A key process in the herpesvirus life cycle involves the recruitment of an ATP-driven terminase to a unique portal vertex to recognize, package and cleave concatemeric dsDNA, ultimately giving rise to a pressurized, genome-containing virion4,5. Although this process has been studied in dsDNA phages6-9-with which herpesviruses bear some similarities-a lack of high-resolution in situ structures of genome-packaging machinery has prevented the elucidation of how these multi-step reactions, which require close coordination among multiple actors, occur in an integrated environment. To better define the structural basis of genome packaging and organization in herpes simplex virus type 1 (HSV-1), we developed sequential localized classification and symmetry relaxation methods to process cryo-electron microscopy (cryo-EM) images of HSV-1 virions, which enabled us to decouple and reconstruct hetero-symmetric and asymmetric elements within the pseudo-icosahedral capsid. Here we present in situ structures of the unique portal vertex, genomic termini and ordered dsDNA coils in the capsid spooled around a disordered dsDNA core. We identify tentacle-like helices and a globular complex capping the portal vertex that is not observed in phages, indicative of herpesvirus-specific adaptations in the DNA-packaging process. Finally, our atomic models of portal vertex elements reveal how the fivefold-related capsid accommodates symmetry mismatch imparted by the dodecameric portal-a longstanding mystery in icosahedral viruses-and inform possible DNA-sequence recognition and headful-sensing pathways involved in genome packaging. This work showcases how to resolve symmetry-mismatched elements in a large eukaryotic virus and provides insights into the mechanisms of herpesvirus genome packaging

Financial Feasibility of Public-Private Partnerships Rent-control On-campus Student Housing

This research considers White Creek Apartments at Texas A&M University and Prince House at National Taiwan University as the research objects, and principally the financial feasibility of these two dormitory projects is discussed and the economic model is used to discuss the utility of this form of providing housing. The two examples were chosen because they represent simple examples from two major economies of interest, the US and the Taiwan economies. The charging rates at Prince House are similar to those of White Creek Apartments, which makes the economic comparisons somewhat simpler. In this thesis, the Public-Private Partnership (PPP) project financing method is briefly introduced as a construction model for other such facilities. Two projects that used PPP are analyzed for this simple case study. The research reviews these projects in different financial climates, and calculates the effect of the financial aspects of the projects and the local economy on the projects’ viability. Finally, the hypothesis that projects financed by Public-Private Partnerships are financially robust against diverse economic circumstances is shown to be true for these two projects. During the analysis of financial feasibility, White Creek Apartments shows a strong income source due to their choice of floor plans. Nevertheless, Prince House has more steady net present profit because of their use of different funding mechanisms, interest rates, and repayment periods. The conclusive reason for the difference in profit is the different characteristics of equity, loans, and bonds. If the initial interest amount is kept the same, a project financed by bonds will cost more. Also, the market interest rate will make the initial repayment larger if the private company chooses to obtain a loan. White Creek Apartments and Prince House both have strong financial feasibility, as their design fits the demand. The difference in financing methods is based on their different financial objectives, such as repayment flexibility or initial repayment amount. Either model works, although in the long run, one wonders at the ultimate utility of state provided facilities of this form