Fifteen months of cumulative CoGeNT data are examined for indications of an annual modulation, a predicted signature of weakly interacting massive particle (WIMP) interactions. Presently available ...data support the presence of a modulated component of unknown origin, with parameters prima facie compatible with a galactic halo composed of light-mass WIMPs. Unoptimized estimators yield a statistical significance for a modulation of ∼2.8σ, limited by the short exposure.
We report on several features in the energy spectrum from an ultralow-noise germanium detector operated deep underground. By implementing a new technique able to reject surface events, a number of ...cosmogenic peaks can be observed for the first time. We discuss an irreducible excess of bulklike events below 3 keV in ionization energy. These could be caused by unknown backgrounds, but also dark matter interactions consistent with DAMA/LIBRA. It is not yet possible to determine their origin. Improved constraints are placed on a cosmological origin for the DAMA/LIBRA effect.
Salmonid species have followed markedly divergent evolutionary trajectories in their interactions with sea lice. While sea lice parasitism poses significant economic, environmental, and animal ...welfare challenges for Atlantic salmon (Salmo salar) aquaculture, coho salmon (Oncorhynchus kisutch) exhibit near-complete resistance to sea lice, achieved through a potent epithelial hyperplasia response leading to rapid louse detachment. The molecular mechanisms underlying these divergent responses to sea lice are unknown. We characterized the cellular and molecular responses of Atlantic salmon and coho salmon to sea lice using single-nuclei RNA sequencing. Juvenile fish were exposed to copepodid sea lice (Lepeophtheirus salmonis), and lice-attached pelvic fin and skin samples were collected 12 h, 24 h, 36 h, 48 h, and 60 h after exposure, along with control samples. Comparative analysis of control and treatment samples revealed an immune and wound-healing response that was common to both species, but attenuated in Atlantic salmon, potentially reflecting greater sea louse immunomodulation. Our results revealed unique but complementary roles of three layers of keratinocytes in the epithelial hyperplasia response leading to rapid sea lice rejection in coho salmon. Our results suggest that basal keratinocytes direct the expansion and mobility of intermediate and, especially, superficial keratinocytes, which eventually encapsulate the parasite. Our results highlight the key role of keratinocytes in coho salmon's sea lice resistance and the diverged biological response of the two salmonid host species when interacting with this parasite. This study has identified key pathways and candidate genes that could be manipulated using various biotechnological solutions to improve Atlantic salmon sea lice resistance.
A claim for evidence of dark matter interactions in the DAMA experiment has been recently reinforced. We employ a new type of germanium detector to conclusively rule out a standard isothermal ...galactic halo of weakly interacting massive particles as the explanation for the annual modulation effect leading to the claim. Bounds are similarly imposed on a suggestion that dark pseudoscalars might lead to the effect. We describe the sensitivity to light dark matter particles achievable with our device, in particular, to next-to-minimal supersymmetric model candidates.
SCISAT‐1, also known as the Atmospheric Chemistry Experiment (ACE), is a Canadian satellite mission for remote sensing of the Earth's atmosphere. It was launched into low Earth circular orbit ...(altitude 650 km, inclination 74°) on 12 Aug. 2003. The primary ACE instrument is a high spectral resolution (0.02 cm−1) Fourier Transform Spectrometer (FTS) operating from 2.2 to 13.3 μm (750–4400 cm−1). The satellite also features a dual spectrophotometer known as MAESTRO with wavelength coverage of 285–1030 nm and spectral resolution of 1–2 nm. A pair of filtered CMOS detector arrays records images of the Sun at 0.525 and 1.02 μm. Working primarily in solar occultation, the satellite provides altitude profile information (typically 10–100 km) for temperature, pressure, and the volume mixing ratios for several dozen molecules of atmospheric interest, as well as atmospheric extinction profiles over the latitudes 85°N to 85°S. This paper presents a mission overview and some of the first scientific results.
Black carbon (BC) concentrations observed in 22 snowpits sampled in the northwest sector of the Greenland ice sheet in April 2014 have allowed us to identify a strong and widespread BC aerosol ...deposition event, which was dated to have accumulated in the pits from two snow storms between 27 July and 2 August 2013. This event comprises a significant portion (57 on average across all pits) of total BC deposition over 10 months (July 2013 to April 2014). Here we link this deposition event to forest fires burning in Canada during summer 2013 using modeling and remote sensing tools. Aerosols were detected by both the Cloud-Aerosol Lidar with Orthogonal Polarization (on board CALIPSO) and Moderate Resolution Imaging Spectroradiometer (Aqua) instruments during transport between Canada and Greenland. We use high-resolution regional chemical transport modeling (WRF-Chem) combined with high-resolution fire emissions (FINNv1.5) to study aerosol emissions, transport, and deposition during this event. The model captures the timing of the BC deposition event and shows that fires in Canada were the main source of deposited BC. However, the model underpredicts BC deposition compared to measurements at all sites by a factor of 2100. Underprediction of modeled BC deposition originates from uncertainties in fire emissions and model treatment of wet removal of aerosols. Improvements in model descriptions of precipitation scavenging and emissions from wildfires are needed to correctly predict deposition, which is critical for determining the climate impacts of aerosols that originate from fires.
We present the results of the first Dalitz plot analysis of the decay D 0 → K-π +η. The analysis is performed on a data set corresponding to an integrated luminosity of 953 fb-1 collected by the ...Belle detector at the asymmetric-energy e+e- KEKB collider. The Dalitz plot is well described by a combination of the six resonant decay channels K- * (892)0 η, K-a0(980)+, K-a2(1320)+, K¯ * (1410)0 η, K* (1680)-π + and K* 2 (1980)-π +, together with Kπ and Kη S-wave components. The decays K* (1680)- → K-η and K* 2 (1980)- → K-η are observed for the first time. We measure ratio of the branching fractions, B(D0→K-π+η) B(D0→K=π+) = 0.500 ± 0.002(stat) ± 0.020(syst) ± 0.003(BPDG). Using the Dalitz fit result, the ratio B(K*(1680)→Kη) B(K*(1680)→Kπ) is measured to be 0.11±0.02(stat)+0.06 =0.04(syst)± 0.04(BPDG); this is much lower than the theoretical expectations (≈ 1) made under the assumption that K* (1680) is a pure 1 3D1 state. The product branching fraction B(D 0 → K* 2 (1980)- → K-ηπ +) = (2.2 +1.7 -1.9 ) × 10-4 is determined. In addition, the πη' contribution to the a0(980)± resonance shape is confirmed with 10.1σ statistical significance using the three-channel Flatté model. We also measure B(D 0 → K¯ * (892)0 η) = (1.41+0.13 -0.12)%. This is consistent with, and more precise than, the current world average (1.02 ± 0.30)%, deviates with a significance of more than 3σ from the theoretical predictions of (0.51-0.92)%.
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