Embedding maximal cliques of sets in maximal cliques of bigger sets

AbstractCharacterizations are obtained of the maximal (k + s)-cliques that contain a given maximal k-clique as a substructure: (1) when s = 1; (2) for arbitrary s when no line of the clique contains exactly one point of the subclique. These characterizations are used to obtain maximal cliques which have fewer lines (for given k) than previously known examples

A Ground-Based Search for Thermal Emission from the Exoplanet TrES-1

Eclipsing planetary systems give us an important window on extrasolar planet atmospheres. By measuring the depth of the secondary eclipse, when the planet moves behind the star, we can estimate the strength of the thermal emission from the day side of the planet. Attaining a ground-based detection of one of these eclipses has proven to be a significant challenge, as time-dependent variations in instrument throughput and atmospheric seeing and absorption overwhelm the small signal of the eclipse at infrared wavelengths. We gathered a series of simultaneous L grism spectra of the transiting planet system TrES-1 and a nearby comparison star of comparable brightness, allowing us to correct for these effects in principle. Combining the data from two eclipses, we demonstrate a detection sensitivity of 0.15% in the eclipse depth relative to the stellar flux. This approaches the sensitivity required to detect the planetary emission, which theoretical models predict should lie between 0.05-0.1% of the stellar flux in our 2.9-4.3 micron bandpass. We explore the factors that ultimately limit the precision of this technique, and discuss potential avenues for future improvements.Comment: 10 pages, 1 table, four figures, accepted for publication in PAS

Small blocking sets of hermitian designs

AbstractA Hermitian design H(q) consists of the points and Hermitian unitals of PG(2,q2). A committee of H(q) is a blocking set of H(q) of minimum cardinality b(H(q)). It is proved that the committees of H(3) are the lines of PG(2, 9) and, for all odd q, that 2q + 2 ≤b(H(q)) < (1 + 7 ln q)(q2 + 1)q−1

The Nonprofit Health Care Corporation Reform Act of 1980

In recent years, Blue Cross/Blue Shield has been the subject of considerable controversy. Its critics charge the non-profit, tax-exempt corporation with being unduly secretive, arrogantly unresponsive to consumer interest and not vigorous in its cost containment efforts. These criticisms, along with a variety of other factors, led to the legislative reform I am here to talk to you about this evening

Nocturnal insomnia symptoms and stress-induced cognitive intrusions in risk for depression: A 2-year prospective study

Nearly half of US adults endorse insomnia symptoms. Sleep problems increase risk for depression during stress, but the mechanisms are unclear. During high stress, individuals having difficulty falling or staying asleep may be vulnerable to cognitive intrusions after stressful events, given that the inability to sleep creates a period of unstructured and socially isolated time in bed. We investigated the unique and combined effects of insomnia symptoms and stress-induced cognitive intrusions on risk for incident depression. 1126 non-depressed US adults with no history of DSM-5 insomnia disorder completed 3 annual web-based surveys on sleep, stress, and depression. We examined whether nocturnal insomnia symptoms and stress-induced cognitive intrusions predicted depression 1y and 2y later. Finally, we compared depression-risk across four groups: non-perseverators with good sleep, non-perseverators with insomnia symptoms, perseverators with good sleep, and perseverators with insomnia symptoms. Insomnia symptoms (β = .10-.13, p \u3c .001) and cognitive intrusions (β = .19-.20, p \u3c .001) predicted depression severity 1y and 2y later. Depression incidence across 2 years was 6.2%. Perseverators with insomnia had the highest rates of depression (13.0%), whereas good sleeping non-perseverators had the lowest rates (3.3%, Relative Risk = 3.94). Perseverators with sleep latency \u3e30 m reported greater depression than good sleeping perseverators (t = 2.09, p \u3c .04). Cognitive intrusions following stress creates a depressogenic mindset, and nocturnal wakefulness may augment the effects of cognitive arousal on depression development. Poor sleepers may be especially vulnerable to cognitive intrusions when having difficulty initiating sleep. As treatable behaviors, nighttime wakefulness and cognitive arousal may be targeted to reduce risk for depression in poor sleepers

A pathogenic cycle between insomnia and cognitive arousal fuels perinatal depression: exploring the roles of nocturnal cognitive arousal and perinatal-focused rumination

STUDY OBJECTIVES: Depression is among the most prevalent perinatal complications, yet modifiable risk factors remain elusive. Over half of perinatal women endorse clinical insomnia symptoms, which are etiologically implicated in depression in nonperinatal samples. Yet, prospective data on perinatal insomnia and depression are mixed. We sought to clarify temporal associations of insomnia and depression during peripartum, and to investigate cognitive arousal as a potential mechanism facilitating this relationship. METHODS: Seventy pregnant women completed sociodemographic information and baseline sleep and mood symptoms between gestational weeks 25 and 30. Beginning at gestational week 30, participants completed 17 weekly online surveys assessing insomnia, depression, and three cognitive arousal indices (nocturnal cognitive arousal, perseverative thinking, and perinatal-focused rumination). Mixed effects models were conducted to test hypotheses. RESULTS: Women were at risk for depression when experiencing insomnia (odds ratio [OR] = 2.36, 95% confidence interval [CI] = 1.28 to 4.35), nocturnal cognitive arousal (OR = 3.05, 95% CI = 1.60 to 5.79), perinatal-focused rumination (OR = 2.05, 95% CI = 1.11 to 3.79), and perseverative thinking (OR = 7.48, 95% CI = 3.90 to 14.32). Prospective analyses revealed bidirectional effects between insomnia and cognitive arousal, and both predicted future depression. Nocturnal cognitive arousal mediated 23-43% of the effect of insomnia on depression. Insomnia mediated 12%-18% of the effect of nocturnal cognitive arousal on depression. A similar pattern was observed with perinatal-focused rumination. Depression did not predict insomnia. CONCLUSION: Nocturnal cognitive arousal, including ruminating on perinatal concerns while trying to fall asleep, fuels insomnia. In turn, lying awake at night provides an opportunity for nocturnal cognitive arousal. This cycle feeds perinatal depression. Daytime cognitive arousal may indirectly disrupt sleep as perseverating during the day persists into the night

Blocking sets in block designs

AbstractA lower bound is obtained for the cardinality of a blocking set in a non-symmetric block design. The known lower bound for blocking sets in symmetric block design is proved to hold (if and) only if the blocking set is a Baer subdesign

Observations of Extrasolar Planets During the non-Cryogenic Spitzer Space Telescope Mission

Precision infrared photometry from Spitzer has enabled the first direct studies of light from extrasolar planets, via observations at secondary eclipse in transiting systems. Current Spitzer results include the first longitudinal temperature map of an extrasolar planet, and the first spectra of their atmospheres. Spitzer has also measured a temperature and precise radius for the first transiting Neptune-sized exoplanet, and is beginning to make precise transit timing measurements to infer the existence of unseen low mass planets. The lack of stellar limb darkening in the infrared facilitates precise radius and transit timing measurements of transiting planets. Warm Spitzer will be capable of a precise radius measurement for Earth-sized planets transiting nearby M-dwarfs, thereby constraining their bulk composition. It will continue to measure thermal emission at secondary eclipse for transiting hot Jupiters, and be able to distinguish between planets having broad band emission versus absorption spectra. It will also be able to measure the orbital phase variation of thermal emission for close-in planets, even non-transiting planets, and these measurements will be of special interest for planets in eccentric orbits. Warm Spitzer will be a significant complement to Kepler, particularly as regards transit timing in the Kepler field. In addition to studying close-in planets, Warm Spitzer will have significant application in sensitive imaging searches for young planets at relatively large angular separations from their parent stars.Comment: 12 pages, 7 figures, to appear in "Science Opportunities for the Warm Spitzer Mission

Highly accurate calculations of the rotationally excited bound states in three-body systems

An effective optimization strategy has been developed to construct highly accurate bound state wave functions in various three-body systems. Our procedure appears to be very effective for computations of weakly bound states and various excited states, including rotationally excited states, i.e. states with $L \ge 1$. The efficiency of our procedure is illustrated by computations of the excited $P^{*}(L = 1)-$states in the $dd\mu, dt\mu$ and $tt\mu$ muonic molecular ions, $P(L = 1)-$states in the non-symmetric $pd\mu, pt\mu$ and $dt\mu$ ions and $2^{1}P(L = 1)-$ and $2^{3}P(L = 1)-$states in He atom(s)