Nica-Toeplitz algebras associated with product systems over right LCM semigroups

We prove uniqueness of representations of Nica-Toeplitz algebras associated to product systems of $C^*$-correspondences over right LCM semigroups by applying our previous abstract uniqueness results developed for $C^*$-precategories. Our results provide an interpretation of conditions identified in work of Fowler and Fowler-Raeburn, and apply also to their crossed product twisted by a product system, in the new context of right LCM semigroups, as well as to a new, Doplicher-Roberts type $C^*$-algebra associated to the Nica-Toeplitz algebra. As a derived construction we develop Nica-Toeplitz crossed products by actions with completely positive maps. This provides a unified framework for Nica-Toeplitz semigroup crossed products by endomorphisms and by transfer operators. We illustrate these two classes of examples with semigroup $C^*$-algebras of right and left semidirect products.Comment: Title changed from "Nica-Toeplitz algebras associated with right tensor C*-precategories over right LCM semigroups: part II examples". The manuscript accepted in J. Math. Anal. App

Differences in health symptoms among residents living near illegal dump sites in Los Laureles Canyon, Tijuana, Mexico: a cross sectional survey.

Living near landfills is a known health hazard prompting recognition of environmental injustice. The study aim was to compare self-reported symptoms of ill health among residents of four neighborhoods, living in haphazardly constructed settlements surrounded by illegal dumpsites in Tijuana, Mexico. One adult from each of 388 households located in Los Laureles Canyon were interviewed about demographics, health status, and symptoms. Distance from each residence to both the nearest dumpsite and the canyon bottom was assessed. The neighborhoods were selected from locations within the canyon, and varied with respect to proximity to dump sites. Residents of San Bernardo reported significantly higher frequencies of ill-health symptoms than the other neighborhoods, including extreme fatigue (OR 3.01 (95% CI 1.6-5.5)), skin problems/irritations (OR 2.73 (95% CI 1.3-5.9)), stomach discomfort (OR 2.47 (1.3-4.8)), eye irritation/tears (OR 2.02 (1.2-3.6)), and confusion/difficulty concentrating (OR 2.39 (1.2-4.8)). Proximity to dumpsites did not explain these results, that varied only slightly when adjusted for distance to nearest dumpsite or distance to the canyon bottom. Because San Bernardo has no paved roads, we hypothesize that dust and the toxicants it carries is a possible explanation for this difference. Studies are needed to further document this association and sources of toxicants

Prevalence of Intimate Partner Violence Among the Maternal-Fetal Medicine Population

Intimate partner violence (IPV) is increasingly understood as an important public health issue. It is well understood that intimate partner violence has many negative effects on its survivors ranging from physical to mental health conditions. The population of people who experience intimate partner violence and population of pregnant women are both vulnerable populations. Examining the two populations together demands a trauma-informed approach and an understanding of the intricacies of both pregnancy and intimate partner violence. While IPV has been studied among the pregnant population, intimate partner violence as it relates to the maternal fetal medicine (MFM) or high-risk pregnancy population is not yet well understood. The purpose of this study is to describe the prevalence and effects of IPV among the MFM population at the Methodist Perinatal Center in Omaha, NE. This study analyzed secondary data obtained through the Abuse Assessment Screen (AAS) that was incorporated into the electronic medical record (EMR) at Methodist Perinatal Center. Data were input into SPSS from which descriptive statistics and a bivariate analysis (Chi square test) were entered. This study found that 5.6% of patients at Methodist Perinatal Center have experienced IPV. Further, this study found that seven maternal and fetal health outcomes are associated with IPV including: BMI ≥25, STI, psychiatric disorder, birth weight \u3c 2.499kg, ultrasound anomaly, non-employer-based insurance (self-pay and Medicaid), and non-married status These results show that it is important to screen for IPV in the high-risk pregnancy setting. As this study shows that IPV occurs and negatively affects women and their children, there is a need for further research on the effects of IPV and development of interventions for the high-risk pregnant population

The Language of Leadership

Companies serve their constituents, produce goods and sell services through the relationships they build which serve to increase the company\u27s market share. This sustains the business. Otherwise, they are forgotten. This appears to be the case with any viable company. Companies, across many industries, cultivate their relationships by utilizing many economic and social tools. But, no tool is more important to gain a corporation competitive edge than the corporate commodity called jargon. I began thinking of the corporate arena as a place that needs effective leadership to explain the jargon that describes it. I decided to investigate the common business jargon used, the characteristics of the current business environment, and to postulate a definition that one aspect of effective leadership is successfutly explaining the obscure new vocabulary of the business environment for employees

Timing and Formation of Linear Dunes South of the Niobrara River Valley, North-Central Nebraska Sand Hills

The Nebraska Sand Hills is a vast (7500 square kilometer) area of grass-stabilized sand dunes. Larger dunes in the Nebraska Sand Hills formed primarily during the Late Pleistocene, but many underwent widespread reactivation during the Holocene. Recent Optically Stimulated Luminescence (OSL) dating indicates that the last major phase of reactivation in the Sand Hills was during the Medieval Warm Period, approximately 800 years ago. Nevertheless, many questions about the evolution of the dunes remain unanswered, particularly regarding the formation of linear dunes in portions of the Sand Hills. This study seeks to understand more about the formation of linear dunes and contribute to the current body of knowledge regarding the Nebraska Sand Hills’ geologic past. The linear dune field investigated in this thesis is located in northwestern Brown County, Nebraska along the southern margin of the Niobrara Valley. These dunes range from 300-600 meters in length, and their relief ranges from 6-10 meters. LiDAR imagery acquired in 2012 reveals that the crests of many of the dunes have characteristic “Y”-shaped junctions in plan view, features that have not yet been fully examined in the Nebraska Sand Hills. Additionally, these dunes are not superimposed onto other dune forms, unlike the majority of linear dunes previously studied in the Nebraska Sand Hills. These dunes are interpreted as simple vegetated linear dunes based on their morphology. Three ground-penetrating radar (GPR) lines, created with 100 MHz frequency antennas penetrated to the bases of the Brown County dunes. The GPR lines depict beds that dip predominately to the south in each dune, unlike previous studies that showed bidirectional dip angles for some linear dunes in the Sand Hills. OSL samples were collected from twelve sediment cores and five hand-auger holes. Twenty-five eolian ages show these dunes stabilized around 2600 years ago and between 950 to 520 years ago, times that correlate to significant periods of drought and dune activity previously recorded in the Nebraska Sand Hills. Several of the deeper (35-40 m) cores contain alluvium that underlies the dunes. On the basis of four OSL ages, the terrace fill underlying the dunes dates to approximately 23,000 to 15,300 years ago. Advisor: Paul R. Hanso

A Dichotomy for Regular Expression Membership Testing

We study regular expression membership testing: Given a regular expression of size $m$ and a string of size $n$, decide whether the string is in the language described by the regular expression. Its classic $O(nm)$ algorithm is one of the big success stories of the 70s, which allowed pattern matching to develop into the standard tool that it is today. Many special cases of pattern matching have been studied that can be solved faster than in quadratic time. However, a systematic study of tractable cases was made possible only recently, with the first conditional lower bounds reported by Backurs and Indyk [FOCS'16]. Restricted to any "type" of homogeneous regular expressions of depth 2 or 3, they either presented a near-linear time algorithm or a quadratic conditional lower bound, with one exception known as the Word Break problem. In this paper we complete their work as follows: 1) We present two almost-linear time algorithms that generalize all known almost-linear time algorithms for special cases of regular expression membership testing. 2) We classify all types, except for the Word Break problem, into almost-linear time or quadratic time assuming the Strong Exponential Time Hypothesis. This extends the classification from depth 2 and 3 to any constant depth. 3) For the Word Break problem we give an improved $\tilde{O}(n m^{1/3} + m)$ algorithm. Surprisingly, we also prove a matching conditional lower bound for combinatorial algorithms. This establishes Word Break as the only intermediate problem. In total, we prove matching upper and lower bounds for any type of bounded-depth homogeneous regular expressions, which yields a full dichotomy for regular expression membership testing

X-ray Emission from Haloes of Simulated Disc Galaxies

Bolometric and 0.2-2 keV X-ray luminosities of the hot gas haloes of simulated disc galaxies have been calculated at redshift z=0. The TreeSPH simulations are fully cosmological and the sample of 44 disc galaxies span a range in characteristic circular speeds of V_c = 130-325 km/s. The galaxies have been obtained in simulations with a considerable range of physical parameters, varying the baryonic fraction, the gas metallicity, the meta-galactic UV field, the cosmology, the dark matter type, and also the numerical resolution. The models are found to be in agreement with the (few) relevant X-ray observations available at present. The amount of hot gas in the haloes is also consistent with constraints from pulsar dispersion measures in the Milky Way. Forthcoming XMM and Chandra observations should enable much more stringent tests and provide constraints on the physical parameters. We find that simple cooling flow models over-predict X-ray luminosities by up to two orders of magnitude for high (but still realistic) cooling efficiencies relative to the models presented here. Our results display a clear trend that increasing cooling efficiency leads to decreasing X-ray luminosities at z=0. The reason is found to be that increased cooling efficiency leads to a decreased fraction of hot gas relative to total baryonic mass inside of the virial radius at present. At gas metal abundances of a third solar this hot gas fraction becomes as low as just a few percent. We also find that most of the X-ray emission comes from the inner parts (inner about 20 kpc) of the hot galactic haloes. Finally, we find for realistic choices of the physical parameters that disc galaxy haloes possibly were more than one order of magnitude brighter in soft X-ray emission at z=1, than at present.Comment: 8 pages, 7 figures, MNRAS LaTeX forma