1,020 research outputs found

    “Minimum Necessary Rigor” in empirically evaluating human–AI work systems

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    The development of AI systems represents a significant investment of funds and time. Assessment is necessary in order to determine whether that investment has paid off. Empirical evaluation of systems in which humans and AI systems act interdependently to accomplish tasks must provide convincing empirical evidence that the work system is learnable and that the technology is usable and useful. We argue that the assessment of human–AI (HAI) systems must be effective but must also be efficient. Bench testing of a prototype of an HAI system cannot require extensive series of large-scale experiments with complex designs. Some of the constraints that are imposed in traditional laboratory research just are not appropriate for the empirical evaluation of HAI systems. We present requirements for avoiding “unnecessary rigor.” They cover study design, research methods, statistical analyses, and online experimentation. These should be applicable to all research intended to evaluate the effectiveness of HAI systems

    Effects of Functional Oils and Monensin Alone or in Combination on Feedlot Cattle Growth and Carcass Composition (Progress Report)

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    This report represents the first trial of a study consisting of a commercial mixture of functional oils (Essential, Oligo Basics USA LLC, Wilmington, DE) used alone and in combination with Monensin to evaluate the effects on steers performance when fed a high concentrate diet. One hundred and twenty steers, average initial weight 322 kg, were divided into five treatments with four pens per treatment and six steers per pen. The treatments were Control (C), Monensin (223 mg/hd/d) (M), Monensin (223 mg/hd/d) + Essential (250 mg/kg DMI) (ME), Essential Low (250 mg/kg DMI) (EL), and Essential High (500 mg/kg DMI) (EH). All steers were fed the same diet on an ad libitum basis, treatments M and EL for 172 days and treatments C, ME, and EH for 179 days. Steers were harvested at an average weight of 617 kg. Results to date suggest that cattle provided functional oils in their diet perform equally as well in the feedyard and in carcass composition as cattle provided a more traditional ionophore in their diet

    Bats of St. Vincent, Lesser Antilles

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    The chiropteran fauna of the island of Saint Vincent, represented by 12 species, is among the most complex in the Lesser Antilles, being represented by four families including Noctilionidae (1 species), Mormoopidae (1), Phyllostomidae (8), and Molossidae (2). This fauna includes four trophic guilds as represented by Noctilio leporinus (piscivore/insectivore); Glossophaga longirostris and Monophyllus plethodon (nectarivore/pollenivore); Artibeus lituratus, A. schwartzi, Brachyphylla cavernarum, Ardops nichollsi, and Sturnira paulsoni (frugivore); and Pteronotus fuscus, Micronycteris buriri, Molossus molossus, and Tadarida brasiliensis (insectivore). One species—Micronycteris buriri—and two subspecies—Sturnira paulsoni paulsoni and Ardops nichollsi vincentensis—are endemic to the island. Recent advancements in population genomics have led to the discovery of the reticulated evolutionary history of Artibeus schwartzi and it is likely that the formation of the hybrid evolutionary trajectory of this species is linked with classical island biogeography. The bat fauna of St. Vincent is unique in the West Indies, characterized by being a crossroads for species, an outpost for both northern and southern species, the boundary for a multi-island bat fauna as marked by Koopman’s Line, and a site of endemism. Based on our studies, we place the bat fauna of St. Vincent as the southern-most island in the Lesser Antillean Faunal Core

    Understanding Farmers’ Forecast Use from Their Beliefs, Values, Social Norms, and Perceived Obstacles

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    Although the accuracy of weather and climate forecasts is continuously improving and new information retrieved from climate data is adding to the understanding of climate variation, use of the forecasts and climate information by farmers in farming decisions has changed little. This lack of change may result from knowledge barriers and psychological, social, and economic factors that undermine farmer motivation to use forecasts and climate information. According to the theory of planned behavior (TPB), the motivation to use forecasts may arise from personal attitudes, social norms, and perceived control or ability to use forecasts in specific decisions. These attributes are examined using data from a survey designed around the TPB and conducted among farming communities in the region of eastern Nebraska and the western U.S. Corn Belt. There were three major findings: 1) the utility and value of the forecasts for farming decisions as perceived by farmers are, on average, around 3.0 on a 0–7 scale, indicating much room to improve attitudes toward the forecast value. 2) The use of forecasts by farmers to influence decisions is likely affected by several social groups that can provide “expert viewpoints” on forecast use. 3) A major obstacle, next to forecast accuracy, is the perceived identity and reliability of the forecast makers. Given the rapidly increasing number of forecasts in this growing service business, the ambiguous identity of forecast providers may have left farmers confused and may have prevented them from developing both trust in forecasts and skills to use them. These findings shed light on productive avenues for increasing the influence of forecasts, which may lead to greater farming productivity. In addition, this study establishes a set of reference points that can be used for comparisons with future studies to quantify changes in forecast use and influence

    In vitro/in vivo assessment of novel 99mTc-bombesin conjugates in human cancer tissue [abstract]

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    Abstract only availableReceptor-specific, radiolabeled peptides are becoming increasingly popular as targeting vectors for the development of new diagnostic radiopharmaceuticals. The over-expression of certain receptors such as the gastrin releasing peptide receptor (GRPr) on human cancer cells makes this method of drug development a viable tool for tumor targeting in vivo. Breast, pancreatic, prostate, gastric, colon, and small-cell lung cancer have demonstrated GRPr expression. In this project, we have conjugated a diaminoproionic acid (DPR) bifunctional chelator to bombesin (BBN) peptide targeting vector by solid phase peptide synthesis. BBN is an analogue of human gastrin releasing peptide (GRP) that binds to the GRPr with high affinity and specificity. Conjugates of the general structure [DPR-(X)-BBN(7-14)NH2] (X = a series of amino acid pharmacokinetic modifiers) were purified by reverse-phase high-performance liquid chromatography and characterized by electrospray-ionization mass spectrometry. Radiolabeling investigations of with fac-[99mTc(CO)3(H2O)3]+ (Isolink®) provided for metallated conjugates of the following general structure: [99mTc(CO)3-DPR-(X)-BBN(7-14)NH2]. These new conjugates demonstrated the ability to target specific human tumors in rodent models. Subsequent radiolabeling studies of [DPR-(X)-BBN(7-14)NH2] with fac-[188Re(CO)3(H2O)3]+, the therapeutic surrogate precursor of Tc-99m, have given us the potential to treat specific human tumors via these new targeting vectors. Detailed radiolabeling protocols, in vitro cell binding studies, and in vivo biodistribution assays will be reported.Harry S. Truman Memorial VA Hospita

    Nonthermal atmospheric pressure plasma enhances mouse limb bud survival, growth, and elongation.

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    The enhanced differentiation of mesenchymal cells into chondrocytes or osteoblasts is of paramount importance in tissue engineering and regenerative therapies. A newly emerging body of evidence demonstrates that appendage regeneration is dependent on reactive oxygen species (ROS) production and signaling. Thus, we hypothesized that mesenchymal cell stimulation by nonthermal (NT)-plasma, which produces and induces ROS, would (1) promote skeletal cell differentiation and (2) limb autopod development. Stimulation with a single treatment of NT-plasma enhanced survival, growth, and elongation of mouse limb autopods in an in vitro organ culture system. Noticeable changes included enhanced development of digit length and definition of digit separation. These changes were coordinated with enhanced Wnt signaling in the distal apical epidermal ridge (AER) and presumptive joint regions. Autopod development continued to advance for approximately 144 h in culture, seemingly overcoming the negative culture environment usually observed in this in vitro system. Real-time quantitative polymerase chain reaction analysis confirmed the up-regulation of chondrogenic transcripts. Mechanistically, NT-plasma increased the number of ROS positive cells in the dorsal epithelium, mesenchyme, and the distal tip of each phalange behind the AER, determined using dihydrorhodamine. The importance of ROS production/signaling during development was further demonstrated by the stunting of digital outgrowth when anti-oxidants were applied. Results of this study show NT-plasma initiated and amplified ROS intracellular signaling to enhance development of the autopod. Parallels between development and regeneration suggest that the potential use of NT-plasma could extend to both tissue engineering and clinical applications to enhance fracture healing, trauma repair, and bone fusion

    Persistence of Protective Immunity to Malaria Induced by DNA Priming and Poxvirus Boosting: Characterization of Effector and Memory CD8+-T-Cell Populations

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    The persistence of immunity to malaria induced in mice by a heterologous DNA priming and poxvirus boosting regimen was characterized. Mice were immunized by priming with DNA vaccine plasmids encoding the Plasmodium yoelii circumsporozoite protein (PyCSP) and murine granulocyte-macrophage colony-stimulating factor and boosting with recombinant vaccinia encoding PyCSP. BALB/c mice immunized with either high-dose (100 µg of p PyCSP plus 30 µg of pGM-CSF) or low-dose (1 µg of p PyCSP plus 1 µg of pGM-CSF DNA) priming were protected against challenge with 50 P. yoelii sporozoites. Protection 2 weeks after immunization was 70 to 100%, persisted at this level for at least 20 weeks, and declined to 30 to 40% by 28 weeks. Eight of eight mice protected at 20 weeks were still protected when rechallenged at 40 weeks. The antigen (Ag)-specific effector CD8+-T-cell population present 2 weeks after boosting had ex vivo Ag-specific cytolytic activity, expressed both gamma interferon (IFN-{gamma}) and tumor necrosis factor alpha, and constituted 12 to 20% of splenic CD8+ T cells. In contrast, the memory CD8+-Ag-specific-cell population at 28 weeks lacked cytolytic activity and constituted only 6% of splenic CD8+ T cells, but at the single-cell level it produced significantly higher levels of IFN-{gamma} than the effectors. High levels of Ag- or parasite-specific antibodies present 2 weeks after boosting had declined three- to sevenfold by 28 weeks. Low-dose priming was similarly immunogenic and as protective as high-dose priming against a 50-, but not a 250-, sporozoite challenge. These results demonstrate that a heterologous priming and boosting vaccination can provide lasting protection against malaria in this model system

    Risk Tolerance, Self-Interest, and Social Preferences

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    We use an experimental method to investigate whether systematic relationships exist across distinct aspects of individual preferences: risk aversion in monetary outcomes, altruism in a twoperson context, and social preferences in a larger group context. Individual preferences across these three contexts are measured, and there is no possibility for risk sharing, wealth effects, or updating expectations of the population choices. We find that social preferences are related to demographic variables, including years of education, gender, and age. Perhaps most importantly, self allocation in a two-person dictator game is related to social preferences in a group context. Participants who are more generous in a dictator game are more likely to vote against their selfinterest in a group decision-making task which we interpret to be expressions of social preferences

    Guidelines for implementation of cystic fibrosis newborn screening programs: Cystic Fibrosis Foundation workshop report

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    Newborn screening for cystic fibrosis offers the opportunity for early intervention and improved outcomes. This summary, resulting from a workshop sponsored by the Cystic Fibrosis Foundation to facilitate implementation of widespread high quality cystic fibrosis newborn screening, outlines the steps necessary for success based on the experience of existing programs. Planning should begin with a workgroup composed of those who will be responsible for the success of the local program, typically including the state newborn screening program director and cystic fibrosis care center directors. The workgroup must develop a screening algorithm based on program resources and goals including mechanisms available for sample collection, regional demographics, the spectrum of cystic fibrosis disease to be detected, and acceptable failure rates of the screen. The workgroup must also ensure that all necessary guidelines and resources for screening, diagnosis, and care be in place prior to cystic fibrosis newborn screening implementation. These include educational materials for parents and primary care providers; systems for screening and for providing diagnostic testing and counseling for screen-positive infants and their families; and protocols for care of this unique population. This summary explores the benefits and risks of various screening algorithms, including complex situations that can occur involving unclear diagnostic results, and provides guidelines and sample materials for state newborn screening programs to develop and implement high quality screening for cystic fibrosis
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