The potential distribution of the Russian wheat aphid (Diuraphis noxia): an updated distribution model including irrigation improves model fit for predicting potential spread.

Diuraphis noxia (Kurdjumov), Russian wheat aphid, is one of the world's most invasive and economically important agricultural pests of wheat and barley. In May 2016, it was found for the first time in Australia, with further sampling confirming it was widespread throughout south-eastern regions. Russian wheat aphid is not yet present in New Zealand. The impacts of this pest if it establishes in New Zealand, could result in serious control problems in wheat- and barley-growing regions. To evaluate whether D. noxia could establish populations in New Zealand we used the climate modelling software CLIMEX to locate where potential viable populations might occur. We re-parameterised the existing CLIMEX model by Hughes and Maywald (1990) by improving the model fit using currently known distribution records of D. noxia, and we also considered the role of irrigation into the potential spread of this invasive insect. The updated model now fits the current known distribution better than the previous Hughes and Maywald CLIMEX model, particularly in temperate and Mediterranean areas in Australia and Europe; and in more semi-arid areas in north-western China and Middle Eastern countries. Our model also highlights new climatically suitable areas for the establishment of D. noxia, not previously reported, including parts of France, the UK and New Zealand. Our results suggest that, when suitable host plants are present, Russian wheat aphid could establish in these regions. The new CLIMEX projections in the present study are useful tools to inform risk assessments and target surveillance and monitoring efforts for identifying susceptible areas to invasion by Russian wheat aphid.

A prospective protocol-based trial of darbepoetin alfa therapy to correct the early anemia following renal transplantation.

Anemia is a common complication accompanying renal transplantation. The evaluation and therapy for posttransplant anemia (PTA) are not standardized and remain controversial. This was a prospective, protocol-driven attempt at early PTA evaluation and management by transplant nurse coordinators. Between 1 and 2 months posttransplantation, 75 consecutive recipients were evaluated for the presence and causes of anemia. Anemic patients were given standard doses of darbepoetin alfa (DA) for 3 months. Response to therapy and patient outcomes were evaluated over 15 months. Twenty-five (33%) of all patients were anemic, including 32% who were erythropoietin (EPO)-deficient and 68% with relative EPO resistance. No patient with early PTA showed an elevated EPO level or increased reticulocytes. Predisposing factors for early PTA included increased numbers of perioperative transfusions, deceased kidney donor, decrease reticulocyte count, and renal insufficiency. DA therapy corrected anemia in 20% of patients at 1 month and in 60% at 3 months. Patients unresponsive to standard DA doses were observed to display reduced renal function and new onset iron deficiency. Patients with prolonged PTA may represent a high-risk population requiring more intensive medical supervision. Nurses were able to efficiently direct DA therapy with only 1.7% protocol violations.

Synergy between chemical and biological control in the IPM of currant-lettuce aphid (Nasonovia ribisnigri) in Canterbury, New Zealand.

Field trials were conducted at four Canterbury, New Zealand locations in 2005-06 to determine if the synergistic effects of biological control by natural enemies and standard drenching techniques controlled lettuce aphid populations throughout the entire growing season. Chemical usage significantly lowered aphid densities in the outer, wrapper and heart leaves compared to control plants at most times. However, in mid-summer, natural enemies, such as the brown lacewing (Micromus tasmaniae), 11-spotted ladybird beetle (Coccinella undecimpunctata) and small hoverfly larvae (Melanostoma fasciatum), were more than sufficient to control lettuce aphids without the use of insecticides. Drenching, in addition to natural enemy attack, appears to be required in early spring and late summer to maintain very low levels of lettuce aphid. Given the potential for imidacloprid resistance to develop, it may be advisable to restrict drenches to these key periods in order to allow populations of natural enemies to maintain control of prey populations. We recommend industry support the validation of action thresholds across different regions within New Zealand and focus on the seasonal biology of predators to assist growers with the sustainable long-term control of lettuce aphids. The inclusion of additional data into an economic model to compare pest damage with predator loading would be useful for growers in managing aphid problems. These results will assist in the continued improvement and development of a sustainable IPM strategy for lettuce aphids in New Zealand and elsewhere.

Micron-pore-sized metallic filter tube membranes for filtration of particulates and water purification.

Robust filtering techniques capable of efficiently removing particulates and biological agents from water or air suffer from plugging, poor rejuvenation, low permeance, and high backpressure. Operational characteristics of pressure-driven separations are in part controlled by the membrane pore size, charge of particulates, transmembrane pressure and the requirement for sufficient water flux to overcome fouling. With long term use filters decline in permeance due to filter-cake plugging of pores, fouling, or filter deterioration. Though metallic filter tube development at ORNL has focused almost exclusively on gas separations, a small study examined the applicability of these membranes for tangential filtering of aqueous suspensions of bacterial-sized particles. A mixture of fluorescent polystyrene microspheres ranging in size from 0.5 to 6 microm in diameter simulated microorganisms in filtration studies. Compared to a commercial filter, the ORNL 0.6 microm filter averaged approximately 10-fold greater filtration efficiency of the small particles, several-fold greater permeance after considerable use and it returned to approximately 85% of the initial flow upon backflushing versus 30% for the commercial filter. After filtering several liters of the particle-containing suspension, the ORNL composite filter still exhibited greater than 50% of its initial permeance while the commercial filter had decreased to less than 20%. When considering a greater filtration efficiency, greater permeance per unit mass, greater percentage of rejuvenation upon backflushing (up to 3-fold), and likely greater performance with extended use, the ORNL 0.6 microm filters can potentially outperform the commercial filter by factors of 100-1,000 fold.

Empirical formulation of a generic query set for clinical information retrieval systems.

Information needs in clinical practice take the form of specific questions about a given clinical situation, and are best satisfied by concise and specific information retrieval. We sought to develop a comprehensive set of generic queries for information retrieval from electronic medical information resources. We collected one hundred and ten real-world questions asked at the point of care in a variety of settings, and from these developed a set of generic queries of which each of the real-world queries could be shown to be a special case. To provide allowed values for each of the concept terms in the queries, we defined generic nouns as unions of UMLS semantic types, and specified which of these were appropriate to each query. We have begun to use the set to index reference texts from general and subspecialty medicine, and found it capable of full text indexing in the clinical domain. We hypothesize that the query set can serve as a basis for more specialized query sets, and that it will remain generalizable to other electronic medical resources, indexing tasks, and non-UMLS controlled vocabularies.

Integration of textual guideline documents with formal guideline knowledge bases.

Numerous approaches have been proposed to integrate the text of guideline documents with guideline-based care systems. Current approaches range from serving marked up guideline text documents to generating advisories using complex guideline knowledge bases. These approaches have integration problems mainly because they tend to rigidly link the knowledge base with text. We are developing a bridge approach that uses an information retrieval technology. The new approach facilitates a versatile decision-support system by using flexible links between the formal structures of the knowledge base and the natural language style of the guideline text.

The usefulness of dynamically categorizing search results.

OBJECTIVE: The authors' goal was to determine whether dynamic categorization, a new technique for organizing search results, is more useful than the two existing organizational techniques: relevance ranking and clustering. They define a useful tool as one that helps users learn about the kinds of information that pertain to their query, find answers to their questions efficiently and easily, and feel satisfied with their search experience. DESIGN: Fifteen patients with breast cancer and their family members completed query-related tasks using all three tools. The authors measured the time it took the subjects to accomplish their tasks, the number of answers to the query that the subjects found in four minutes, and the number of new answers that they could recall at the end of the study. Subjects also completed a user-satisfaction questionnaire. RESULTS: The results showed that patients with breast cancer and their family members could find significantly (P: < 0.05) more answers in a fixed amount of time and were significantly (P: < 0.05) more satisfied with their search experience when they used the dynamic categorization tool than when they used either the cluster tool or the ranking tool. Subjects indicated that the dynamic categorization tool provided an organization of search results that was more clear, easy to use, accurate, precise, and helpful than those of the other tools. CONCLUSION: The experiments indicate that dynamic categorization is an effective and useful approach for organizing search results. Tools that use this technique will help patients and their families gain quick and easy access to important medical information.

Knowledge requirements for automated inference of medical textbook markup.

Indexing medical text in journals or textbooks requires a tremendous amount of resources. We tested two algorithms for automatically indexing nouns, noun-modifiers, and noun phrases, and inferring selected binary relations between UMLS concepts in a textbook of infectious disease. Sixty-six percent of nouns and noun-modifiers and 81% of noun phrases were correctly matched to UMLS concepts. Semantic relations were identified with 100% specificity and 94% sensitivity. For some medical sub-domains, these algorithms could permit expeditious generation of more complex indexing.

Automation and integration of components for generalized semantic markup of electronic medical texts.

Our group has built an information retrieval system based on a complex semantic markup of medical textbooks. We describe the construction of a set of web-based knowledge-acquisition tools that expedites the collection and maintenance of the concepts required for text markup and the search interface required for information retrieval from the marked text. In the text markup system, domain experts (DEs) identify sections of text that contain one or more elements from a finite set of concepts. End users can then query the text using a predefined set of questions, each of which identifies a subset of complementary concepts. The search process matches that subset of concepts to relevant points in the text. The current process requires that the DE invest significant time to generate the required concepts and questions. We propose a new system--called ACQUIRE (Acquisition of Concepts and Queries in an Integrated Retrieval Environment)--that assists a DE in two essential tasks in the text-markup process. First, it helps her to develop, edit, and maintain the concept model: the set of concepts with which she marks the text. Second, ACQUIRE helps her to develop a query model: the set of specific questions that end users can later use to search the marked text. The DE incorporates concepts from the concept model when she creates the questions in the query model. The major benefit of the ACQUIRE system is a reduction in the time and effort required for the text-markup process. We compared the process of concept- and query-model creation using ACQUIRE to the process used in previous work by rebuilding two existing models that we previously constructed manually. We observed a significant decrease in the time required to build and maintain the concept and query models.

MYCIN II: design and implementation of a therapy reference with complex content-based indexing.

We describe the construction of MYCIN II, a prototype system that provides for content-based markup and search of a forthcoming clinical therapeutics textbook, Antimicrobial Therapy and Vaccines. Existing commercial search technology for digital references utilizes generic tools such as textword-based searches with geographical or statistical refinements. We suggest that the drawbacks of such systems significantly restrict their use in everyday clinical practice. This is in spite of the fact that there is a great need for the information contained within these same references. The system we describe is intended to supplement keyword searching so that certain important questions can be asked easily and can be answered reliably (in terms of precision and recall). Our method attacks this problem in a restricted domain of knowledge-clinical infectious disease. For example, we would like to be able to answer the class of questions exemplified by the following query: "What antimicrobial agents can be used to treat endocarditis caused by Eikenella corrodens?" We have compiled and analyzed a list of such questions to develop a concept-based markup scheme. This scheme was then applied within an HTML markup to electronically "highlight" passages from three textbook chapters. We constructed a functioning web-based search interface. Our system also provides semi-automated querying of PubMed using our concept markup and the user's actions as a guide.

Automated planning target volume generation: an evaluation pitting a computer-based tool against human experts.

PURPOSE: Software tools are seeing increased use in three-dimensional treatment planning. However, the development of these tools frequently omits careful evaluation before placing them in clinical use. This study demonstrates the application of a rigorous evaluation methodology using blinded peer review to an automated software tool that produces ICRU-50 planning target volumes (PTVs). METHODS AND MATERIALS: Seven physicians from three different institutions involved in three-dimensional treatment planning participated in the evaluation. Four physicians drew partial PTVs on nine test cases, consisting of four nasopharynx and five lung primaries. Using the same information provided to the human experts, the computer tool generated PTVs for comparison. The remaining three physicians, designated evaluators, individually reviewed the PTVs for acceptability. To exclude bias, the evaluators were blinded to the source (human or computer) of the PTVs they reviewed. Their scorings of the PTVs were statistically examined to determine if the computer tool performed as well as the human experts. RESULTS: The computer tool was as successful as the human experts in generating PTVs. Failures were primarily attributable to insufficient margins around the clinical target volume and to encroachment upon critical structures. In a qualitative analysis, the human and computer experts displayed similar types and distributions of errors. CONCLUSIONS: Rigorous evaluation of computer-based radiotherapy tools requires comparison to current practice and can reveal areas for improvement before the tool enters clinical practice.

Lightweight, mobile E-mail for intra-clinic communication.

We have developed a mobile messaging system designed for use in the clinic setting. The system is designed to facilitate quick, informal, interactions that occur in a clinical setting, e.g., requests for assistance or information. The system includes safeguards to make sure that the sender of a message is aware if a message is not read in a timely fashion. Evaluation of the system shows message delivery was about 50% slower than our target of 30 seconds. Although the mobile device used is fairly small when combined with a radio unit, it is too bulky and users did not necessarily carry the system with them. This led to delays (over eleven minutes on average) before messages were seen. We expect that improvements in hardware and clinical software will lead to more common use of such adjunct software systems.

The PEN-Ivory project: exploring user-interface design for the selection of items from large controlled vocabularies of medicine.

OBJECTIVE: To explore different user-interface designs for structured progress note entry, with a long-term goal of developing design guidelines for user interfaces where users select items from large medical vocabularies. DESIGN: The authors created eight different prototypes of a pen-based progress-note-writing system called PEN-Ivory. Each prototype allows physicians to write patient progress notes using simple pen-based gestures such as circle, line-out, and scratch-out. The result of an interaction with PEN-Ivory is a progress note in English prose. The eight prototypes were designed in a principled way, so that they differ from one another in just one of three different user-interface characteristics. MEASUREMENTS: Five of the eight prototypes were tested by measuring the time it took 15 users, each using a distinct prototype, to document three patient cases consisting of a total of 63 medical findings. RESULTS: The prototype that allowed the fastest data entry had the following three user-interface characteristics: it used a paging rather than a scrolling form, it used a fixed palette of modifiers rather than a dynamic "pop-up" palette, and it made available all findings from the controlled vocabulary at once rather than displaying only a subset of findings generated by analyzing the patient's problem list. CONCLUSION: Even simple design changes to a user interface can make dramatic differences in user performance. The authors discuss possible influences on performance, such as positional constancy, user uncertainty and system anticipation, that may contribute significantly to the effectiveness of systems that display menus of items from large controlled vocabularies of medicine.

Toward reusable software components at the point of care.

An architecture built from five software components -a Router, Parser, Matcher, Mapper, and Server -fulfills key requirements common to several point-of-care information and knowledge processing tasks. The requirements include problem-list creation, exploiting the contents of the Electronic Medical Record for the patient at hand, knowledge access, and support for semantic visualization and software agents. The components use the National Library of Medicine Unified Medical Language System to create and exploit lexical closure-a state in which terms, text and reference models are represented explicitly and consistently. Preliminary versions of the components are in use in an oncology knowledge server.

Optimizing physician access to surgical intensive care unit laboratory information through mobile computing.

Approximately 30 minutes of computer access time are required by surgical residents at Stanford University Medical Center (SUMC) to examine the lab values of all patients on a surgical intensive care unit (ICU) service, a task that must be performed several times a day. To reduce the time accessing this information and simultaneously increase the readability and currency of the data, we have created a mobile, pen-based user interface and software system that delivers lab results to surgeons in the ICU. The ScroungeMaster system, loaded on a portable tablet computer, retrieves lab results for a subset of patients from the central laboratory computer and stores them in a local database cache. The cache can be updated on command; this update takes approximately 2.7 minutes for all ICU patients being followed by the surgeon, and can be performed as a background task while the user continues to access selected lab results. The user interface presents lab results according to physiologic system. Which labs are displayed first is governed by a layout selection algorithm based on previous accesses to the patient's lab information, physician preferences, and the nature of the patient's medical condition. Initial evaluation of the system has shown that physicians prefer the ScroungeMaster interface to that of existing systems at SUMC and are satisfied with the system's performance. We discuss the evolution of ScroungeMaster and make observations on changes to physician work flow with the presence of mobile, pen-based computing in the ICU.

Ex vivo evaluation of ferromagnetism, heating, and artifacts of breast tissue expanders exposed to a 1.5-T MR system.

Three breast tissue expanders were evaluated for compatibility with MR imaging (1.5 Tesla). The metallic components of the breast tissue expanders were shown to be nonferromagnetic, heating < or = .2 degrees C and the artifacts varied. These results indicate that MR procedures may be performed safely in patients with these implants; however, artifacts may obscure implant leaks or breast lesions if located near and metal portion of the breast tissue expanders.