Higgs Boson Decays to Dark Photons through the Vectorized Lepton Portal

Vector-like fermions charged under both the Standard Model and a new dark gauge group arise in many theories of new physics. If these fermions include an electroweak doublet and singlet with equal dark charges, they can potentially connect to the Higgs field through a Yukawa coupling in analogy to the standard neutrino portal. With such a coupling, fermion loops generate exotic decays of the Higgs boson to one or more dark vector bosons. In this work we study a minimal realization of this scenario with an Abelian dark group. We investigate the potential new Higgs decays modes, we compute their rates, and we study the prospects for observing them at the Large Hadron Collider and beyond given the other experimental constraints on the theory. We also discuss extensions of the theory to non-Abelian dark groups.Comment: 32 pages, 5 figures, updated to match JHEP versio

The relationship between out-of-school activities and positive youth development : an investigation of the influences of families and communities

There is growing evidence that participation in constructive leisure activities facilitates positive youth development. Empirical evidence also supports the influence of families and communities on positive developmental outcomes for adolescents. This study examined the relationship between attitudes toward family and community, participation in structured out-of-school activities, and pro-social behavior. As predicted, community aspects such as opportunities available and the attitudes the youth held toward the community, as well as their attitude toward family were predictive of activity involvement. Activity involvement, in turn, was predictive of pro-social behavior. Attitude toward family was also predictive of attitude toward the community. Attitude toward community was a direct predictor of the positive developmental outcome of pro-social behavior, although contrary to the original hypothesis, family influences did not have a direct effect on pro-social behavior. Implications continued practice and change for a variety of sectors in the positive youth development field such as educators and educational institutions, youth-serving organizations, families, and policy makers are discussed, along with recommendations for continued research in this field

Tumor-derived exosomes drive immunosuppressive macrophages in a pre-metastatic niche through NF-Kβ dependent glycolytic metabolic reprogramming.

The formation of a pre-metastatic niche is a fundamental requirement for primary tumor metastasis. One of the defining characteristics of a pre-metastatic niche is infiltration of immunosuppressive macrophages. However, how these macrophages acquire their immunosuppressive phenotype remains largely unexplored. Here, we demonstrate that tumor-derived exosomes (TDE) polarize macrophages towards an immunosuppressive phenotype characterized by increased PD-L1 expression through NF-kB-dependent metabolic reprogramming in mice and humans. While NF-κB has previously been shown to act as a direct transcription factor for PD-L1, we report a novel mechanism where TDE-induced NF-κB activation drives PD-L1 expression by augmenting the glycolytic capacity of macrophages through two separate pathways. First, NF-κB increases glucose uptake into macrophages via a HIF-1α/GLUT-1-dependent mechanism. Secondly, elevated NOS2-dependent nitric oxide inhibits mitochondrial oxidative phosphorylation resulting in an increased conversion of pyruvate to lactate. Lactate then feeds back on NF-κB further increasing PD-L1 expression. Analysis of metastasis negative draining lymph nodes of non-small cell lung cancer patients revealed that macrophage PD-L1 expression positively correlates with expression levels of GLUT-1 and exosomal release genes YKT6 and TSG101 from primary tumors. Collectively, our study provides a novel mechanism by which macrophages within a pre-metastatic niche acquire their immunosuppressive phenotype and identifies an important link between exosomes, metabolism, and metastasis

REPRODUCTION AND RECRUITMENT OF AMERICAN LOBSTER (HOMARUS AMERICANUS) IN THE GREAT BAY ESTUARY, NEW HAMPSHIRE

The overall goal of this research project was to determine if lobsters reproduce and settle in the Great Bay estuary (GBE), NH. First, I mapped the distribution and abundance of ovigerous lobsters carrying late-stage eggs in the estuary, during May and June of 2015. Ovigerous lobsters were concentrated in Little Bay and adjacent sections of the Piscataqua River, with CPUE in these areas of 0.12 ± 0.02 lobsters/trap haul. Very few were found in the regions furthest from the coast. Next, egg samples were collected from these lobsters, as well as from ovigerous lobsters captured along the NH coast and their hatch dates were determined based on their stage and the rate of egg development at their respective temperatures. The mean predicted hatching date of eggs carried by GBE lobsters was June-09 11.8 days (SD), while the mean predicted hatch date of eggs carried by coastal lobsters was July-01 9.5 days, nearly three weeks later. The GBE eggs most likely hatched three weeks later because of the difference in water temperatures between the two areas. Plankton tows were then conducted to determine if larvae were present in the water column at the time when I predicted that the eggs carried by GBE females would be hatching. The predicted hatch dates for the 35 stage I larvae captured ranged from May-21 through July-19, with a mean predicted hatching date of June-28 17.9 days . This encompasses almost a two-month period, which is longer than either range of predicted hatch dates from eggs obtained either from estuarine or coastal lobsters. However, the larvae that hatched earliest overlapped with when ovigerous lobsters hatched their eggs in the GBE, indicating that a portion of these larvae originated in the estuary. Strong tidal currents influence particle transport (i.e., planktonic larvae) in GBE and my next goal was to determine if these currents would retain larvae, or carry them out to the Gulf of Maine. Surface currents were characterized using surface drifters (n=21) deployed near areas with the highest densities of ovigerous lobsters carrying late stage eggs in the GBE, as well as in the Piscataqua River (n=6) to determine if larvae were transported into the GBE from areas near to the coast. Drifter movements were extrapolated over 8-16 days (when larvae develop and settle) and over this time period, drifters released from all three locations were retained in the estuary. In fact, these data suggested that the greatest abundance of juvenile lobsters should be in areas that also had the highest densities of ovigerous females. Finally, to test this prediction and to determine if lobster larvae did, in fact, settle in the GBE, the distribution, abundance and composition (size frequency, sex ratio) of juvenile lobsters in the GBE was assessed using trawls consisting of two pairs of modified ventless traps and two pairs of juvenile collector traps. Sampling occurred at six study sites on a spatial gradient, ranging from the upper Piscataqua River to Great Bay proper. The smallest lobster (38 mm carapace length (CL)) was captured in the Piscataqua River, and the average size of lobsters increased as sites furthest up into the GBE (ranging from 66.51 0.78 mm CL (SEM) in the river (n=185) to 88.67 2.82 mm CL, n=2, in Great Bay proper). Only adult lobsters were found at the sites furthest up in the estuary, and the adult sex ratio also became more skewed towards males in these areas. However, the sex ratios of juvenile lobsters were 1:1 at the four sites where they were captured (Fisher’s Exact test, p=0.995), indicating that the skewed sex ratios of adult lobsters were likely the result of differential movements of males and females. Taken together, these data provide support for a residential and self-recruiting lobster population in the GBE, although the timing of larvae, as well as the characterization of currents using drifters reinforces that, to an extent, the GBE lobster population is supplemented by adults that migrate into the estuary and larvae originating from coastal lobsters that are carried into the GBE by tidal currents

The Effects Of Elevated Total Dissolved Solids On The Behavior And Survival Of The Allegheny Mountain Dusky Salamander, Desmognathus Ochrophaeus

Elevated total dissolved solids (TDS) have been found in streams in Pennsylvania primarily due to unconventional natural gas development (UNGD) and mine drainage. TDS is the concentration of dissolved salts in water. To understand the effects of TDS on amphibians, a semi-aquatic salamander (Desmognathus ochrophaeus exposed to synthetic solutions containing TDS up to 5,000 ppm. In an initial study, animals exposed to a solution of approximately 2,000 ppm TDS containing elevated sulfate experienced reduced survival and decreased locomotory activity. Follow-up studies were consistent with the hypothesis that elevated TDS had adverse effects on survival, but effects were not seen unless the TDS was closer to 5,000 ppm. In all studies, larger animals were more prone to adverse effects of TDS. Results indicated that elevated TDS can have adverse effects on D. ochrophaeus further research is needed to understand the doses and conditions at which effects are evident

Dark Matter Antibaryons from a Supersymmetric Hidden Sector

The cosmological origin of both dark and baryonic matter can be explained through a unified mechanism called hylogenesis where baryon and antibaryon number are divided between the visible sector and a GeV-scale hidden sector, while the Universe remains net baryon symmetric. The "missing" antibaryons, in the form of exotic hidden states, are the dark matter. We study model-building, cosmological, and phenomenological aspects of this scenario within the framework of supersymmetry, which naturally stabilizes the light hidden sector and electroweak mass scales. Inelastic dark matter scattering on visible matter destroys nucleons, and nucleon decay searches offer a novel avenue for the direct detection of the hidden antibaryonic dark matter sea.Comment: 33 pages, 10 figures. Minor changes to match published versio

Tapered optical fibers as tools for probing magneto-optical trap characteristics

We present a novel technique for measuring the characteristics of a magneto-optical trap for cold atoms by monitoring the spontaneous emission from trapped atoms coupled into the guided mode of a tapered optical nanofiber. We show that the nanofiber is highly sensitive to very small numbers of atoms close to its surface. The size and shape of the MOT, determined by translating the cold atom cloud across the tapered fiber, is in excellent agreement with measurements obtained using the conventional method of fluorescence imaging using a CCD camera. The coupling of atomic fluorescence into the tapered fiber also allows us to monitor the loading and lifetime of the trap. The results are compared to those achieved by focusing the MOT fluorescence onto a photodiode and it was seen that the tapered fiber gives slightly longer loading and lifetime measurements due to the sensitivity of the fiber, even when very few atoms are present.Comment: 21 pages, 5 figure