Geologic Studies of the Platte River, South-Central Nebraska and Adjacent Areas—Geologic Maps, Subsurface Study, and Geologic History

The Platte River of south-central Nebraska was studied at three scales to place the river in its geological context and to trace its evolution through geologic time. At the largest scale the Elm Creek West and the Newark 7.5 minute quadrangles were mapped. These quadrangles are located just west and just east of Kearney and serve to illustrate the main geomorphic elements of the present Platte River Valley. The central elements of the quadrangles are the Platte River channels, islands, and bottomlands, which are flanked by terraces that step up away from the river to the north and south. Significant other elements of the landscape are eolian sand and loess deposits. The geologic maps are supplemented by topographic profi les of the mapped terraces and graphical representations of subsurface units in test wells that occur within the quadrangles. An intermediate-scale study consisted of examining descriptions of well cuttings in a 17 county area in south-central Nebraska, which includes the Platte River Valley, and building a database of information about sediment lithology and thickness. The wells penetrated a sequence of gravel, sand, silt, and clay beds from the ground surface to the top of the subsurface Tertiary Ogallala Group or Cretaceous formations. The sequence consists of Pliocene-, Pleistocene-, and Holocene-age strata that document the deposition of a veneer of alluvium by late Tertiary and Quaternary streams intermixed with and overlain by wind-blown loess. Various isopleth and structure maps illustrate the distribution and alluvial architecture of the sedimentary sequence, and support the interpretation of former positions of the Platte River. A regional-scale study consisted of documenting the geo- logic history of the Front Range and adjacent mountains and depositional areas east of the mountains in Colorado, Wyoming, Kansas, and Nebraska from the end of the Cretaceous Period, about 65 million years ago, to the present. The structural and sedimentary history of the region is outlined, and a series of paleogeographic maps shows the development of the drainage system in the east-central Rocky Mountains and adjacent Plains. Ancestral South Platte, North Platte, and Laramie Rivers are recognized as early as the late Eocene, although the South Platte probably fl owed to the southeast from the mountain front at that time. Deposits of the North Platte River are recognized on the west side of the Medicine Bow Mountains of Wyoming in the Miocene, and the presence of distinctive rock clasts indicates that the Laramie River fl owed from the North Park area of Colorado northeast across a filled Laramie Basin and the Laramie Range of southeastern Wyoming in the Miocene. The present drainage system developed in the late Miocene to the Pliocene and included the capture and diversion of the South Platte River into its present channel. The combined North and South Platte Rivers deposited gravel and sand across Nebraska and fl owed southeast from Kearney, Nebraska through the middle to late Pleistocene. Within the past 25,000 years the Platte River below Kearney was captured and diverted into its present course and confined there by bounding valley walls of loess

The (mis)use of subjective process measures in software engineering

A variety of measures are used in software engineering research to develop an understanding of the software process and product. These measures fall into three broad categories: quantitative, characteristics, and subjective. Quantitative measures are those to which a numerical value can be assigned, for example effort or lines of code (LOC). Characteristics describe the software process or product; they might include programming language or the type of application. While such factors do not provide a quantitative measurement of a process or product, they do help characterize them. Subjective measures (as defined in this study) are those that are based on the opinion or opinions of individuals; they are somewhat unique and difficult to quantify. Capturing of subjective measure data typically involves development of some type of scale. For example, 'team experience' is one of the subjective measures that were collected and studied by the Software Engineering Laboratory (SEL). Certainly, team experience could have an impact on the software process or product; actually measuring a team's experience, however, is not a strictly mathematical exercise. Simply adding up each team member's years of experience appears inadequate. In fact, most researchers would agree that 'years' do not directly translate into 'experience.' Team experience must be defined subjectively and then a scale must be developed e.g., high experience versus low experience; or high, medium, low experience; or a different or more granular scale. Using this type of scale, a particular team's overall experience can be compared with that of other teams in the development environment. Defining, collecting, and scaling subjective measures is difficult. First, precise definitions of the measures must be established. Next, choices must be made about whose opinions will be solicited to constitute the data. Finally, care must be given to defining the right scale and level of granularity for measurement

Size-tuneable nanometric MRI contrast agents for the imaging of molecular weight dependent transport processes

Purpose: To evaluate size-tuneable nanomeric glycol-chitosan-DTPA-Gd conjugates as MRI contrast agents for the imaging of molecular weight (MW) dependent transport processes. Material & Methods: Glycol chitosans (GC) – DTPA conjugates of precisely controlled MWs were synthesised and evaluated in mice against Gd-DTPA using times series of high-resolution MRI images of trunk, head, and xenograft flank tumours. All animal studies were approved by the local ethics committee and the UK authorities. Results: GC-DTPA modification ratio was one DTPA per 3.9 – 5.13 of GC monomers. GC-DTAPGd provided overall superior contrast compared to Gd-DTPA with the duration of the enhancement depending on MW (≥ 1h for 40kD). Kidneys showed early enhancement also in the renal pelvis suggesting renal elimination. Imaging of the head with GC-DTPA-Gd allowed detailed anatomical identification of specific blood vessels in particular with the high MW agent. Sequential high-resolution isotropic imaging of established A431 xenograft flank tumours with DTPA-Gd and GC-DTPA-Gd demonstrated that the initial delivery of the contrast agents was well correlated with blood supply. Subsequent tissue transport was primarily by diffusion and was limited by molecular weight. The data also highlight the role of heterogeneity in CA distribution that was again more prominent for the high MW agent. Conclusion: GC-DTPA-Gd with identical physical chemical properties but precisely controlled MW allow isotropic high-resolution three-dimensional imaging of molecular weight dependent transport processes which could potentially lead to clinical biomarkers for molecular weight dependent drug transport and support selection of suitable tumour models for pre-clinical development

Incidence and survival after acute myocardial infarction in indigenous and non-indigenous people in the Northern Territory, 1992-2004

Objective: To estimate the incidence and survival rates of acute myocardial infarction (AMI) for Northern Territory Indigenous and non-Indigenous populations.Design and participants: Retrospective cohort study for all new AMI cases recorded in hospital inpatient data or registered as an ischaemic heart disease (IHD) death between 1992 and 2004.Main outcome measures: Population-based incidence and survival rates by age, sex, Indigenous status, remoteness of residence and year of diagnosis.Results: Over the 13-year study period, the incidence of AMI increased 60% in the NT Indigenous population (incidence rate ratio [IRR], 1.04; 95% CI, 1.02–1.06), but decreased 20% in the non-Indigenous population (IRR, 0.98; 95% CI, 0.97–1.00). Over the same period, there was an improvement in all-cases survival (ie, survival with and without hospital admission) for the NT Indigenous population due to a reduction in deaths both pre-hospital and after hospital admission (death rates reduced by 56% and 50%, respectively). The non-Indigenous all-cases death rate was reduced by 29% as a consequence of improved survival after hospital admission; there was no significant change in pre-hospital survival in this population. Important factors that affected outcome in all people after AMI were sex (better survival for women), age (survival declined with increasing age), remoteness (worse outcomes for non-Indigenous residents of remote areas), year of diagnosis and Indigenous status (hazard ratio, 1.44; 95% CI, 1.21–1.70).Conclusions: Our results show that the increasing IHD mortality in the NT Indigenous population is a consequence of a rise in AMI incidence, while at the same time there has been some improvement in Indigenous AMI survival rates. The simultaneous decrease in IHD mortality in NT non-Indigenous people was a result of reduced AMI incidence and improved survival after AMI in those admitted to hospital. Our results inform population-specific strategies for a systemwide response to AMI management

The Near Earth Object Scout Spacecraft: A Low Cost Approach to in-situ Characterization of the NEO Population

In this paper we describe a micro/nano satellite spacecraft and a supporting mission profile and architecture designed to enable preliminary in-situ characterization of a significant number of Near Earth Objects (NEOs) at reasonable cost. The spacecraft will be referred to as the NEO Scout. NEO Scout spacecraft are to be placed in GTO, GEO, or cis-lunar space as secondary payloads on launch vehicles headed for GTO or beyond and will begin their mission after deployment from the launcher. A distinguishing key feature of the NEO scout system is to design the mission timeline and spacecraft to rendezvous with and land on the target NEOs during close approach to the Earth-Moon system using low-thrust/high- impulse propulsion systems. Mission feasibility and preliminary design analysis are presented along with detailed trajectory calculations. The use of micro/nano satellites in low-cost interplanetary exploration is attracting increasing attention and is the subject of several annual workshops and published design studies (1-4). The NEO population consists of those asteroids and short period comets orbiting the Sun with a perihelion of 1.3 astronomical units or less (5-8). As of July 30, 2013 10065 Near-Earth objects have been discovered. The spin rate, mass, density, surface physical (especially mechanical) properties, composition, and mineralogy of the vast majority of these objects are highly uncertain and the limited available telescopic remote sensing data imply a very diverse population (5-8). In-situ measurements by robotic spacecraft are urgently needed to provide the characterization data needed to support hardware and mission design for more ambitious human and robotic NEO operations. Large numbers of NEOs move into close proximity with the Earth-Moon system every year (9). The JPL Near-Earth Object Human Space Flight Accessible Targets Study (NHATS) (10) has produced detailed mission profile and delta V requirements for various NEO missions ranging from 30 to 420 days in duration and assuming chemical propulsion. Similar studies have been reported assuming high power electric propulsion for manned NEO rendezvous missions (11). The delta V requirement breakdown and mission profile data from references 10 and 11 are used as a basis for sizing the NEO Scout spacecraft and for conducting preliminary feasibility assessments using the Tsiokolvsky rocket equation, a (worst-case) delta V requirement of 10 km/sec, and a maximum spacecraft dry mass of 20 kg. Using chemical propellant for a 10 km/sec delta V drives spacecraft wet mass well above 300 kg so that chemical propulsion is a non-starter for the proposed mission profile and spacecraft wet mass limits. In contrast, a solar electric propulsion system needs only 8 kg of Xe propellant to accelerate the spacecraft to 10 km/sec in 163 days with 0.02 N of thrust and 500 W of power from1.6 sq m of 29% efficient solar panels. In a second example, accelerating a 4 kg payload to 7 km/sec over 180 days requires about 6.7 kg of propellant and 1.2 kg of solar panels (12 kg total spacecraft wet mass)

The extent of violence inflicted on adolescent Aboriginal girls in the Northern Territory

Background: Australian Aboriginal and Torres Strait Islander women are at very high risk of violence but there is little evidence about the age at which their higher exposure to violence commences. The aim of this study was to investigate violence inflicted on Aboriginal girls during childhood and adolescence, relative to Aboriginal boys and non-Aboriginal girls. Methods: This was a retrospective cohort study using de-identified administrative data for NT residents aged 0-17 years. This study used linked hospital and child protection data to investigate hospitalization for injury caused by assault and substantiated child maltreatment involving violence (physical and sexual abuse). Results: The incidence of assault hospitalization and substantiated physical/sexual abuse was much higher for Aboriginal than non-Aboriginal adolescents but similar for girls and boys to about age ten, then increased much more for Aboriginal girls than boys. In the 14-17 age-group, assault hospitalization incidence was 125% higher for Aboriginal girls than boys but 56% lower for non-Aboriginal girls than boys. 4.6% of Aboriginal girls were hospitalized (30.9% more than once) for assault between twelfth and eighteenth birthdays, compared to 3.4% of Aboriginal boys and 0.3% of non-Aboriginal girls. The incidence of assault hospitalization during adolescence was over three times higher for Aboriginal children who had substantiated child maltreatment during childhood. Conclusion: The very high levels of violence suffered by Aboriginal women commence in the pre-teen years. Non-Aboriginal girls are ‘protected’ from the rising levels of violence that boys experience as they progress through adolescence, but Aboriginal girls are not afforded such protection

Trance Logic, Age Regression, and Incomplete Responding: A Preliminary Investigation of Contextual Influences

Fifty-four hypnotizable and 49 unhypnotizable simulating subjects were age regressed to age five and asked to write the sentence “I am participating in a psychological experiment” embedded in either “standard” suggestions for regression or in the context of a suggested dream. As predicted, hypnotizable subjects were sensitive to the context manipulation (i.e., dream vs. standard), evidencing more correct or “adult” spelling (“trance logic”) during age regression when the dream context encouraged a melding of fantasy and reality. Simulators’ performance was stable across conditions. Consistent with the hypothesis that incomplete responding is at the heart of incongruous spelling during age regression, the hypnotizable and simulating subjects who evinced the least compelling experiences of age regression were the most likely to spell “adult” words correctly (exhibit “trance logic”). Finally, none of the 31 subjects whose handwriting was rated as “childlike and primitive” spelled the word “psychological” correctly, providing clear evidence that subjects who were the most responsive to the age regression suggestion fail to exhibit trance logic

Building an experience factory for maintenance

This paper reports the preliminary results of a study of the software maintenance process in the Flight Dynamics Division (FDD) of the National Aeronautics and Space Administration/Goddard Space Flight Center (NASA/GSFC). This study is being conducted by the Software Engineering Laboratory (SEL), a research organization sponsored by the Software Engineering Branch of the FDD, which investigates the effectiveness of software engineering technologies when applied to the development of applications software. This software maintenance study began in October 1993 and is being conducted using the Quality Improvement Paradigm (QIP), a process improvement strategy based on three iterative steps: understanding, assessing, and packaging. The preliminary results represent the outcome of the understanding phase, during which SEL researchers characterized the maintenance environment, product, and process. Findings indicate that a combination of quantitative and qualitative analysis is effective for studying the software maintenance process, that additional measures should be collected for maintenance (as opposed to new development), and that characteristics such as effort, error rate, and productivity are best considered on a 'release' basis rather than on a project basis. The research thus far has documented some basic differences between new development and software maintenance. It lays the foundation for further application of the QIP to investigate means of improving the maintenance process and product in the FDD