136 research outputs found
H.E.A.T. - Home Energy Automation Technology
The purpose of this project is to explore residential household climate control systems and develop a viable product concept that integrates any and all heating, ventilation, and air conditioning (HVAC) sources into an automated electronic control system. This project will incorporate a microcontroller-based modular system that provides multiple communication mediums to adapt to most household configurations. This system will utilize a web-based control server that implements efficient climate control algorithms, resulting in improved heating and cooling efficiency for residential and small-business consumers
Association mapping of seed quality traits using the Canadian flax (Linum usitatissimum L.) core collection
KEY MESSAGE: The identification of stable QTL for seed quality traits by association mapping of a diverse panel of linseed accessions establishes the foundation for assisted breeding and future fine mapping in linseed. ABSTRACT: Linseed oil is valued for its food and non-food applications. Modifying its oil content and fatty acid (FA) profiles to meet market needs in a timely manner requires clear understanding of their quantitative trait loci (QTL) architectures, which have received little attention to date. Association mapping is an efficient approach to identify QTL in germplasm collections. In this study, we explored the quantitative nature of seed quality traits including oil content (OIL), palmitic acid, stearic acid, oleic acid, linoleic acid (LIO) linolenic acid (LIN) and iodine value in a flax core collection of 390 accessions assayed with 460 microsatellite markers. The core collection was grown in a modified augmented design at two locations over 3 years and phenotypic data for all seven traits were obtained from all six environments. Significant phenotypic diversity and moderate to high heritability for each trait (0.73–0.99) were observed. Most of the candidate QTL were stable as revealed by multivariate analyses. Nine candidate QTL were identified, varying from one for OIL to three for LIO and LIN. Candidate QTL for LIO and LIN co-localized with QTL previously identified in bi-parental populations and some mapped nearby genes known to be involved in the FA biosynthesis pathway. Fifty-eight percent of the QTL alleles were absent (private) in the Canadian cultivars suggesting that the core collection possesses QTL alleles potentially useful to improve seed quality traits. The candidate QTL identified herein will establish the foundation for future marker-assisted breeding in linseed. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00122-014-2264-4) contains supplementary material, which is available to authorized users
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Conserved Nonexonic Elements: A Novel Class of Marker for Phylogenomics
Abstract Noncoding markers have a particular appeal as tools for phylogenomic analysis because, at least in vertebrates, they appear less subject to strong variation in GC content among lineages. Thus far, ultraconserved elements (UCEs) and introns have been the most widely used noncoding markers. Here we analyze and study the evolutionary properties of a new type of noncoding marker, conserved nonexonic elements (CNEEs), which consists of noncoding elements that are estimated to evolve slower than the neutral rate across a set of species. Although they often include UCEs, CNEEs are distinct from UCEs because they are not ultraconserved, and, most importantly, the core region alone is analyzed, rather than both the core and its flanking regions. Using a data set of 16 birds plus an alligator outgroup, and ∼3600–∼3800 loci per marker type, we found that although CNEEs were less variable than bioinformatically derived UCEs or introns and in some cases exhibited a slower approach to branch resolution as determined by phylogenomic subsampling, the quality of CNEE alignments was superior to those of the other markers, with fewer gaps and missing species. Phylogenetic resolution using coalescent approaches was comparable among the three marker types, with most nodes being fully and congruently resolved. Comparison of phylogenetic results across the three marker types indicated that one branch, the sister group to the passerine + falcon clade, was resolved differently and with moderate (>70%) bootstrap support between CNEEs and UCEs or introns. Overall, CNEEs appear to be promising as phylogenomic markers, yielding phylogenetic resolution as high as for UCEs and introns but with fewer gaps, less ambiguity in alignments and with patterns of nucleotide substitution more consistent with the assumptions of commonly used methods of phylogenetic analysis
Deep Thermal Infrared Imaging of HR 8799 bcde: New Atmospheric Constraints and Limits on a Fifth Planet
We present new (3.8 ) and Br- (4.05 ) data
and reprocessed archival data for the young, planet-hosting star HR
8799 obtained with Keck/NIRC2, VLT/NaCo and Subaru/IRCS. We detect all four HR
8799 planets in each dataset at a moderate to high signal-to-noise (SNR
6-15). We fail to identify a fifth planet, "HR 8799 f", at 15
at a 5- confidence level: one suggestive, marginally significant
residual at 0.2" is most likely a PSF artifact. Assuming companion ages of 30
and the Baraffe (Spiegel \& Burrows) planet cooling models, we rule out
an HR 8799 f with mass of 5 (7 ), 7 (10 ), and 12
(13 ) at 12 , 9 , and 5 ,
respectively. All four HR 8799 planets have red early T dwarf-like -
[4.05] colors, suggesting that their SEDs peak in between the and
broadband filters. We find no statistically significant difference
in HR 8799 cde's colors. Atmosphere models assuming thick, patchy clouds appear
to better match HR 8799 bcde's photometry than models assuming a uniform cloud
layer. While non-equilibrium carbon chemistry is required to explain HR 8799
bc's photometry/spectra, evidence for it from HR 8799 de's photometry is
weaker. Future, deep IR spectroscopy/spectrophotometry with the Gemini Planet
Imager, SCExAO/CHARIS, and other facilities may clarify whether the planets are
chemically similar or heterogeneous.Comment: 18 pages, 6 Tables, and 9 Figures. Fig. 1a is the key figure.
Accepted for publication in Ap
A planetary system with two transiting mini-Neptunes near the radius valley transition around the bright M dwarf TOI-776
We report the discovery and characterization of two transiting planets around the bright M1 V star LP 961-53 (TOI-776, J = 8.5 mag, M = 0.54 ± 0.03 M_⊙) detected during Sector 10 observations of the Transiting Exoplanet Survey Satellite (TESS). Combining the TESS photometry with HARPS radial velocities, as well as ground-based follow-up transit observations from the MEarth and LCOGT telescopes, for the inner planet, TOI-776 b, we measured a period of P_b = 8.25 d, a radius of R_b = 1.85 ± 0.13 R_⊕, and a mass of M_b = 4.0 ± 0.9 M_⊕; and for the outer planet, TOI-776 c, a period of P_c = 15.66 d, a radius of R_c = 2.02 ± 0.14 R ⊕, and a mass of M_c = 5.3 ± 1.8 M_⊕. The Doppler data shows one additional signal, with a period of ~34 d, associated with the rotational period of the star. The analysis of fifteen years of ground-based photometric monitoring data and the inspection of different spectral line indicators confirm this assumption. The bulk densities of TOI-776 b and c allow for a wide range of possible interior and atmospheric compositions. However, both planets have retained a significant atmosphere, with slightly different envelope mass fractions. Thanks to their location near the radius gap for M dwarfs, we can start to explore the mechanism(s) responsible for the radius valley emergence around low-mass stars as compared to solar-like stars. While a larger sample of well-characterized planets in this parameter space is still needed to draw firm conclusions, we tentatively estimate that the stellar mass below which thermally-driven mass loss is no longer the main formation pathway for sculpting the radius valley is between 0.63 and 0.54 M_⊙. Due to the brightness of the star, the TOI-776 system is also an excellent target for the James Webb Space Telescope, providing a remarkable laboratory in which to break the degeneracy in planetary interior models and to test formation and evolution theories of small planets around low-mass stars
In Vivo Deficiency of Both C/EBPβ and C/EBPε Results in Highly Defective Myeloid Differentiation and Lack of Cytokine Response
The CCAAT/enhancer binding proteins (C/EBPs) are transcription factors involved in hematopoietic cell development and induction of several inflammatory mediators. Here, we generated C/EBPβ and C/EBPε double-knockout (bbee) mice and compared their phenotypes to those of single deficient (bbEE and BBee) and wild-type (BBEE) mice. The bbee mice were highly susceptible to fatal infections and died within 2–3 months. Morphologically, their neutrophils were blocked at the myelocytes/metamyelocytes stage, and clonogenic assays of bone marrow cells indicated a significant decrease in the number of myeloid colonies of the bbee mice. In addition, the proportion of hematopoietic progenitor cells [Lin(−)Sca1(+)c-Kit(+)] in the bone marrow of the bbee mice was significantly increased, reflecting the defective differentiation of the myeloid compartment. Furthermore, microarray expression analysis of LPS- and IFNγ-activated bone marrow-derived macrophages from bbee compared to single knockout mice revealed decreased expression of essential immune response-related genes and networks, including some direct C/EBP-targets such as Marco and Clec4e. Overall, the phenotype of the bbee mice is distinct from either the bbEE or BBee mice, demonstrating that both transcription factors are crucial for the maturation of neutrophils and macrophages, as well as the innate immune system, and can at least in part compensate for each other in the single knockout mice
A Search for Technosignatures Around 11,680 Stars with the Green Bank Telescope at 1.15-1.73 GHz
We conducted a search for narrowband radio signals over four observing
sessions in 2020-2023 with the L-band receiver (1.15-1.73 GHz) of the 100 m
diameter Green Bank Telescope. We pointed the telescope in the directions of 62
TESS Objects of Interest, capturing radio emissions from a total of ~11,680
stars and planetary systems in the ~9 arcminute beam of the telescope. All
detections were either automatically rejected or visually inspected and
confirmed to be of anthropogenic nature. In this work, we also quantified the
end-to-end efficiency of radio SETI pipelines with a signal injection and
recovery analysis. The UCLA SETI pipeline recovers 94.0% of the injected
signals over the usable frequency range of the receiver and 98.7% of the
injections when regions of dense RFI are excluded. In another pipeline that
uses incoherent sums of 51 consecutive spectra, the recovery rate is ~15 times
smaller at ~6%. The pipeline efficiency affects calculations of transmitter
prevalence and SETI search volume. Accordingly, we developed an improved Drake
Figure of Merit and a formalism to place upper limits on transmitter prevalence
that take the pipeline efficiency and transmitter duty cycle into account.
Based on our observations, we can state at the 95% confidence level that fewer
than 6.6% of stars within 100 pc host a transmitter that is detectable in our
search (EIRP > 1e13 W). For stars within 20,000 ly, the fraction of stars with
detectable transmitters (EIRP > 5e16 W) is at most 3e-4. Finally, we showed
that the UCLA SETI pipeline natively detects the signals detected with AI
techniques by Ma et al. (2023).Comment: 22 pages, 9 figures, submitted to AJ, revise
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