Investigation of Colorado front range winter storms using a nonhydrostatic mesoscale numerical model designed for operational use

Fall 1993.Also issued as author's sdissertation (Ph.D.) -- Colorado State University, 1993.Includes bibliographical references.State-of-the-art data sources such as Doppler radar, automated surface observations, wind profiler, digital satellite, and aircraft reports are for the first time providing the capability to generate real-time, operational three-dimensional gridded data sets with sufficient spatial and temporal resolutions to diagnose the structure and evolution of mesoscale systems. A prototype data assimilation system of this type, called the Local Analysis and Prediction System (LAPS), is being developed at the National Oceanic and Atmospheric System's Forecast Systems Laboratory (FSL). The investigation utilizes the three-dimensional LAPS analyses for initialization of the full physics, nonhydrostatic Regional Atmospheric Modeling System (RAMS) model developed at the Colorado State University to create a system capable of generating operational mesoscale predictions. The LAPS/RAMS system structured for operational use can add significant value to existing operational model output and can provide an improved scientific understanding of mesoscale weather events. The results a.re presented through two case study analyses, the 7 January 1992 Colorado Front Range blizzard and the 8-9 March 1992 eastern Colorado snowstorm. Both cases a.re ideal for this investigation due to the significant mesoscale variation observed in the precipitation and flow structure. The case study results demonstrate the ability to successfully detect and predict mesoscale features using a mesoscale numerical model initialized with high resolution (10 km horizontal grid interval), non­ homogeneous data. Conceptual models of the two snowstorms are developed by utilizing the RAMS model output in combination with observations and other larger domain model simulations. The strong influence of the Colorado topography on the resultant flow is suggested by the generation of a lee vortex that frequently develops east of the Front Range and south of the Cheyenne Ridge in stable, northwest synoptic flow. The lee vortex, often called the "Longmont anticyclone", exhibits surface flow characteristics that are similar to results from low Froude number flow around an isolated obstacle. A series of numerical experiments using RAMS with idealized topography and horizontally homogeneous initial conditions are presented to investigate typical low Froude number flow characteristics in the vicinity of barriers representative of the Colorado topography. The results are compared to the findings of previous investigations and to the case study observations and numerical predictions. The findings suggest that the Colorado orography significantly altered the low-level flow in both case studies resulting in mesoscale variation of observed precipitation. Improved representation of the topography by the model led to the majority of the forecast improvement

All their eggs in one basket: a rocky reef nursery for the longnose skate (Raja rhina Jordan & Gilbert, 1880) in the southern California Bight

Skates (family Rajidae) are oviparous and lay tough, thick-walled eggs. At least some skate species lay their eggs in spatially restricted nursery grounds where embryos develop and hatch (Hitz, 1964; Hoff, 2007). After hatching, neonates may quickly leave the nursery grounds (Hoff, 2007). Egg densities in these small areas may be quite high. As an example, in the eastern Bering Sea, a site <2 km2 harbored eggs of Alaska skate (Bathyraja parmifera) exceeding 500,000/km2. All skate nursery grounds have been identified over soft sea floors (Lucifora and García, 2004; Hoff, 2007)

Abortion services in a high-needs district: a community-based model of care

INTRODUCTION: In 2009, a high-deprivation district health board in New Zealand set up a community-based abortion clinic in order to provide a local service and to avoid out-of-region referrals. The service offers medical abortions for women with pregnancies of up to 63 days' gestation, and surgical abortion with local anaesthetic for women with pregnancies of up to 14 weeks' gestation. AIM: To describe the services developed and assess safety and timeliness for the first year of community-based services. METHODS: An audit of clinical records for patients seen in 2010 was performed in order to obtain data on location of services, timeliness, safety and complications. RESULTS: Eighty-two percent of locally provided abortions in 2010 were medical abortions, completed on average less than two days after referral to the service. One percent of patients experienced haemorrhaging post abortion, and 4% had retained products. These rates are within accepted standards for an abortion service. DISCUSSION: This report illustrates that a community-based model of care can be both clinically and culturally safe, while providing a much-needed service to a high-needs population

Refining Nodes and Edges of State Machines

State machines are hierarchical automata that are widely used to structure complex behavioural specifications. We develop two notions of refinement of state machines, node refinement and edge refinement. We compare the two notions by means of examples and argue that, by adopting simple conventions, they can be combined into one method of refinement. In the combined method, node refinement can be used to develop architectural aspects of a model and edge refinement to develop algorithmic aspects. The two notions of refinement are grounded in previous work. Event-B is used as the foundation for our refinement theory and UML-B state machine refinement influences the style of node refinement. Hence we propose a method with direct proof of state machine refinement avoiding the detour via Event-B that is needed by UML-B

Feline Neonatal Medicine

Veterinary pediatrics, with the possible exception of the foal, is an unfortunately neglected discipline. Feline pediatrics, specifically, is almost entirely neglected in the literature. This neglect is out of proponion with the numbers of kittens seen by veterinarians for both routine health checks and treatment of diseases. Consequently, clients are often ill informed regarding kitten care and an unnecessary number of kittens die that would, with proper care, survive to become healthy pets and show animals. More imponantly, sick or weak kittens should not be considered genetically inferior and be destroyed on the assumption that they would never develop normally. In many situations, feline pediatric medicine can be both practical and economical. Many therapeutic measures effective in kittens are easy, inexpensive, and can be attempted with minimal time and money invested

CAUSES OF SIMULTANEOUS LEE AND UPWIND RECORD SNOWFALL AND EXTRAORDINARY SNOWFALL VARIATION IN A ROCKY MOUNTAIN BLIZZARD

We describe our investigation of an extreme snowfall event in the Colorado Rocky Mountains during Mar 2003. This event was characterized by extraordinary micro-scale snowfall variability and record snowfall both upwind and in the lee of the 3000 m north-south oriented barrier. We utilize observational analysis and numerical sensitivity tests with the MM5 mesoscale model to test our hypotheses. Stunning micro-scale snowfall variability observed in-situ and visualized by satellite is found to be a consequence of local terrain-induced warming and reduced microphysical efficiency and the amplified influence of this effect due to the relatively warm temperatures accompanying this storm. Record snowfall (2 m) downwind of the barrier simultaneous with record snowfall (2.2 m) upwind is very rare climatologically, and is found to be caused, in effect, by the exceptional synoptic dimensions of this storm. A rare combination of, 1) moist, deep inflow, 2) a reversal of the mid-latitude westerlies to the tropopause overlying a well-developed barrier jet for an extended period and, 3) static stability favoring cross-barrier microphysical production and hydrometeor transport rather than drying, are implicated

Velocity autocorrelation functions of hard-sphere fluids: Long-time tails upon undercooling

Molecular dynamics simulations are employed to obtain the velocity autocorrelation function (VAF) for hard spheres, spanning a wide range of volume fractions from dilute to high-density metastable fluids. For all volume fractions below freezing, Alder&#039;s classical positive 3/2 long-time tail is observed. For volume fractions from 0.45 to 0.48 the VAF becomes negative, before becoming positive and decaying with the positive 3/2 long-time tail. At the freezing volume fraction (0.494) the Alder 3/2 tail is not observed. At higher volume fractions a negative tail with an exponent of 5/2 emerges, which coincides with the long-time tail of a Lorentz gas

APC-β-catenin-TCF signaling silences the intestinal guanylin-GUCY2C tumor suppressor axis.

Sporadic colorectal cancer initiates with mutations in APC or its degradation target β-catenin, producing TCF-dependent nuclear transcription driving tumorigenesis. The intestinal epithelial receptor, GUCY2C, with its canonical paracrine hormone guanylin, regulates homeostatic signaling along the crypt-surface axis opposing tumorigenesis. Here, we reveal that expression of the guanylin hormone, but not the GUCY2C receptor, is lost at the earliest stages of transformation in APC-dependent tumors in humans and mice. Hormone loss, which silences GUCY2C signaling, reflects transcriptional repression mediated by mutant APC-β-catenin-TCF programs in the nucleus. These studies support a pathophysiological model of intestinal tumorigenesis in which mutant APC-β-catenin-TCF transcriptional regulation eliminates guanylin expression at tumor initiation, silencing GUCY2C signaling which, in turn, dysregulates intestinal homeostatic mechanisms contributing to tumor progression. They expand the mechanistic paradigm for colorectal cancer from a disease of irreversible mutations in APC and β-catenin to one of guanylin hormone loss whose replacement, and reconstitution of GUCY2C signaling, could prevent tumorigenesis

The relationship between adiposity and stature in prepubertal children with celiac disease

Background and Aim: The pathogenesis of short stature in celiac disease (CD) is unknown. Obese children are generally taller than their non-obese peers; however, the role of adiposity on stature in CD is unclear. Our aim was to determine the association between adiposity and stature in CD. Subjects and methods: We compared the anthropometric characteristics of prepubertal children of ages 3-12 years, with biopsy-proven CD (n=40) and who were not on gluten-free diet, to same aged, prepubertal non-CD children (n=50). Body mass index (BMI) was calculated using the formula weight/height2. Sex-adjusted midparental target height (MPTH) standard deviation score (SDS) was calculated using National Children Health Statistics data for 18-year-old adults. Data were expressed as mean±standard deviation. Results: CD subjects had significantly lower BMI SDS than controls (0.61±1.22 vs. 1.28±1.60, p=0.027) but were not significantly shorter than the controls (-0.05±1.21 vs. 0.21±1.71, p=0.41). When the patients were subdivided into the normal-weight and overweight/obese groups, the normal-weight CD patients were of similar height as the normal-weight controls (p=0.76) but were significantly shorter than both the overweight/obese controls (p=0.003). The MPTH SDS did not differ between the groups. Conclusions: Overweight/obese prepubertal children with CD were taller than both their normal-weight CD peers and the normal-weight controls, but were of similar height as the overweight/obese control subjects