Agricultural Health and Safety: A Research Agenda for Agricultural Economists

Replaced with revised version of paper 01/26/06.Health Economics and Policy, Teaching/Communication/Extension/Profession,

Codes and finite geometries

We explore the connections between finite geometry and algebraic coding theory, giving a rather full account of the Reed-Muller and generalized Reed-Muller codes. Some of the results and many of the proofs are new but this is largely an expository effort that relies heavily on the work of Delsarte et al. and of Charpin. The necessary geometric background is sketched before we begin the discussion of the Reed-Muller codes and their p-ary analogues. We prove all the classical results concerning these codes and include a discussion of the group-algebra approach and prove Berman's theorem characterizing the codes as powers of the radical. Included also is a discussion of the characterization of affine-invariant cyclic codes given by Kasami, Lin and Peterson and its generalization by Delsarte. our theme throughout this work is the relationship between these codes and the codes coming from both affine and projective geometries. The final section develops the theory in the more difficult case in which the field is not of prime order, here must look at subfield subcodes - which complicates the connection with the geometric codes, which are codesover the prime subfield of the field of the geometry

Individual rules for trail pattern formation in Argentine ants (Linepithema humile)

We studied the formation of trail patterns by Argentine ants exploring an empty arena. Using a novel imaging and analysis technique we estimated pheromone concentrations at all spatial positions in the experimental arena and at different times. Then we derived the response function of individual ants to pheromone concentrations by looking at correlations between concentrations and changes in speed or direction of the ants. Ants were found to turn in response to local pheromone concentrations, while their speed was largely unaffected by these concentrations. Ants did not integrate pheromone concentrations over time, with the concentration of pheromone in a 1 cm radius in front of the ant determining the turning angle. The response to pheromone was found to follow a Weber's Law, such that the difference between quantities of pheromone on the two sides of the ant divided by their sum determines the magnitude of the turning angle. This proportional response is in apparent contradiction with the well-established non-linear choice function used in the literature to model the results of binary bridge experiments in ant colonies (Deneubourg et al. 1990). However, agent based simulations implementing the Weber's Law response function led to the formation of trails and reproduced results reported in the literature. We show analytically that a sigmoidal response, analogous to that in the classical Deneubourg model for collective decision making, can be derived from the individual Weber-type response to pheromone concentrations that we have established in our experiments when directional noise around the preferred direction of movement of the ants is assumed.Comment: final version, 9 figures, submitted to Plos Computational Biology (accepted

Codes from adjacency matrices of uniform subset graphs

Studies of the p-ary codes from the adjacency matrices of uniform subset graphs Γ(n,k,r)Γ(n,k,r) and their reflexive associates have shown that a particular family of codes defined on the subsets are intimately related to the codes from these graphs. We describe these codes here and examine their relation to some particular classes of uniform subset graphs. In particular we include a complete analysis of the p-ary codes from Γ(n,3,r)Γ(n,3,r) for p≥5p≥5 , thus extending earlier results for p=2,3p=2,3

Die Nerven und das Bindegewebe der Pia des Menschen im mikrophotographischen Bild

Die Nerven der Pia des Menschen können mit der Silberkarbonattechnik von del Rio Hortega an Ganzpräparaten mikrophotographisch klar wiedergegeben und zwanglos in 2 Systeme eingeteilt werden: 1. Das perivaskuläre System, das von Nerven gebildet wird, die nach ihrem Eintritt in die Pia direkt zu den Gefäßen verlaufen und die letzteren mit einem dichten Geflecht umgeben. Das Grundnetz, welches von Nerven gebildet wird, die a) gleich nach ihrem Eintritt in die Pia sich aufsplittern und den Hauptteil des Grundnetzes bilden; b) von Nerven, welche von einem gefäßwärts verlaufenden Nerven sich abzweigen; c) von Nerven, welche zum perivaskulären Plexus gehören, und schließlich d) von starken Nervenbündeln, welche innerhalb des Grundnetzes zahlreiche Plexus bilden und allmählich in dasselbe übergehen. Das Grundnetz selbst erscheint histologisch als ein in sich geschlossenes Ganzes und enthält keine besonderen Endformationen. Die Strukturen des Bindegewebes zerfallen ebenfalls in 2 Systeme: A. das perivaskuläre Gewebe und B. das die Maschen der Gefäße ausfüllende Netz. A. Die oberflächliche Schicht der Adventitia besteht aus dichten, gleichmäßig starken, parallel verlaufenden Fasern. Die 2. Lage enthält große, ovale oder birnenförmige Zellen mit zahlreichen Ausläufern, welche in der Literatur vielfach als Ganglienzellen gedeutet worden sind. Die 3. Schicht ist durch ovale Auftreibungen ihrer Fasern charakterisiert und die 4. besteht aus zarten, der Media anliegenden Fibrillen. B. Die Maschen zwischen den Gefäßen sind von einem dichten Gewirr sich sternförmig kreuzender Fasern ausgefüllt. Es bestehen direkte Verbindungen zwischen dem Bindegewebe und den Zellen der Arachnoidea. The nerves and connective tissue of the human pia were investigated with the silver carbonate method of del Rio Hortega . The nerves of the pia form two distinctly different but closely associated systems: 1. the perivascular system is made up of nerves which enter the pia, give numerous branches to the ground network (Grundnetz) (Fig. 1), and form perivascular plexuses (Figs. 2, 3, 4) and, 2. the ground network (Grundnetz), which spreads out over the entire pia and is supported by connective tissue structures. The ground network is formed by: A) nerves which enter the pia and split into numerous branches (Fig. 5), B) ramification of perivascular nerves (Figs. 6, 7, 8, 9), C) numerous plexuses derived from coarse nerves which have no direct connection with the vessels; these plexuses gradually merge with the ground network (Figs. 10, 11, 12). The ground network is a dense interwoven structure without demonstrable terminal formations (Fig. 13). The latter have been found only on the media of vessels (Fig. 14). The connective tissue structures are no less complicated than those of the nerves and can also be subdivided into two systems: 1. the adventitia, and 2. the interwoven network of stellate fibers which fills in the space between the vessels. In the adventitia there can be distinguished four layers: A) the upper which contains coarse parallel fibers (Fig. 15), B) the second which is characterized by large, oval or round elements with numerous processes (Fig. 16), C) the third which is composed of fibers with numerous bead-like swellings along their course (Figs. 17, 18), and D) the fourth which consists of delicate fibers which lie directly on the media (Fig. 19). The meshes between the vessels are filled with stellate fiber formations (Fig. 20). The connective tissue fibers of the upper strata of the pia are connected with the processes of the cells of the arachnoidea and are surrounded by numerous connective tissue loops (Fig. 21). Les nerfs et le tissue conjonctif de la pie-mère humaine furent vérifiés à l'aide de la microphotographie de pièces du tissue entier imprégnées à la méthode de del Rio Hortega . Les nerfs montrent deux systèmes différents: 1. Le système périvasculaire formé par des nerfs qui en entrant dans la piemère joignent les vaisseaux en entournant ceux-ci avec un réseau dense.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41654/1/702_2005_Article_BF01227770.pd

The decline in stomach cancer mortality: exploration of future trends in seven European countries

Mortality from stomach cancer has fallen steadily during the past decades. The aim of this paper is to assess the implication of a possible continuation of the decline in stomach cancer mortality until the year 2030. Annual rates of decline in stomach cancer mortality from 1980 to 2005 were determined for the Netherlands, United Kingdom, France, and four Nordic countries on the basis of regression analysis. Mortality rates were extrapolated until 2030, assuming the same rate of decline as in the past, using three possible scenarios. The absolute numbers of deaths were projected taking into account data on the ageing of national populations. Stomach cancer mortality rates declined between 1980 and 2005 at about the same rate (3.6–4.9% per year) for both men and women in all countries. The rate of decline did not level off in recent years, and it was not smaller in countries with lower overall mortality rates in 1980. If this decline were to continue into the future, stomach cancer mortality rates would decline with about 66% between 2005 and 2030 in most populations, while the absolute number of stomach cancer deaths would diminish by about 50%. Thus, in view of the strong, stable and consistent mortality declines in recent decades, and despite population ageing, stomach cancer is likely to become far less important as a cause of death in Europe in the future

Critical research gaps and translational priorities for the successful prevention and treatment of breast cancer

INTRODUCTION Breast cancer remains a significant scientific, clinical and societal challenge. This gap analysis has reviewed and critically assessed enduring issues and new challenges emerging from recent research, and proposes strategies for translating solutions into practice. METHODS More than 100 internationally recognised specialist breast cancer scientists, clinicians and healthcare professionals collaborated to address nine thematic areas: genetics, epigenetics and epidemiology; molecular pathology and cell biology; hormonal influences and endocrine therapy; imaging, detection and screening; current/novel therapies and biomarkers; drug resistance; metastasis, angiogenesis, circulating tumour cells, cancer 'stem' cells; risk and prevention; living with and managing breast cancer and its treatment. The groups developed summary papers through an iterative process which, following further appraisal from experts and patients, were melded into this summary account. RESULTS The 10 major gaps identified were: (1) understanding the functions and contextual interactions of genetic and epigenetic changes in normal breast development and during malignant transformation; (2) how to implement sustainable lifestyle changes (diet, exercise and weight) and chemopreventive strategies; (3) the need for tailored screening approaches including clinically actionable tests; (4) enhancing knowledge of molecular drivers behind breast cancer subtypes, progression and metastasis; (5) understanding the molecular mechanisms of tumour heterogeneity, dormancy, de novo or acquired resistance and how to target key nodes in these dynamic processes; (6) developing validated markers for chemosensitivity and radiosensitivity; (7) understanding the optimal duration, sequencing and rational combinations of treatment for improved personalised therapy; (8) validating multimodality imaging biomarkers for minimally invasive diagnosis and monitoring of responses in primary and metastatic disease; (9) developing interventions and support to improve the survivorship experience; (10) a continuing need for clinical material for translational research derived from normal breast, blood, primary, relapsed, metastatic and drug-resistant cancers with expert bioinformatics support to maximise its utility. The proposed infrastructural enablers include enhanced resources to support clinically relevant in vitro and in vivo tumour models; improved access to appropriate, fully annotated clinical samples; extended biomarker discovery, validation and standardisation; and facilitated cross-discipline working. CONCLUSIONS With resources to conduct further high-quality targeted research focusing on the gaps identified, increased knowledge translating into improved clinical care should be achievable within five years

Vegetarian diets are associated with healthy mood states: a cross-sectional study in Seventh Day Adventist adults

<p>Abstract</p> <p>Background</p> <p>The physical health status of vegetarians has been extensively reported, but there is limited research regarding the mental health status of vegetarians, particularly with regard to mood. Vegetarian diets exclude fish, the major dietary source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), critical regulators of brain cell structure and function. Omnivorous diets low in EPA and DHA are linked to impaired mood states in observational and experimental studies.</p> <p>Methods</p> <p>We examined associations between mood state and polyunsaturated fatty acid intake as a result of adherence to a vegetarian or omnivorous diet in a cross-sectional study of 138 healthy Seventh Day Adventist men and women residing in the Southwest. Participants completed a quantitative food frequency questionnaire, Depression Anxiety Stress Scale (DASS), and Profile of Mood States (POMS) questionnaires.</p> <p>Results</p> <p>Vegetarians (VEG:n = 60) reported significantly less negative emotion than omnivores (OMN:n = 78) as measured by both mean total DASS and POMS scores (8.32 ± 0.88 vs 17.51 ± 1.88, <it>p </it>= .000 and 0.10 ± 1.99 vs 15.33 ± 3.10, <it>p </it>= .007, respectively). VEG reported significantly lower mean intakes of EPA (<it>p </it>< .001), DHA (<it>p </it>< .001), as well as the omega-6 fatty acid, arachidonic acid (AA; <it>p </it>< .001), and reported higher mean intakes of shorter-chain α-linolenic acid (<it>p </it>< .001) and linoleic acid (<it>p </it>< .001) than OMN. Mean total DASS and POMS scores were positively related to mean intakes of EPA (<it>p </it>< 0.05), DHA (<it>p </it>< 0.05), and AA (<it>p </it>< 0.05), and inversely related to intakes of ALA (<it>p </it>< 0.05), and LA (<it>p </it>< 0.05), indicating that participants with low intakes of EPA, DHA, and AA and high intakes of ALA and LA had better mood.</p> <p>Conclusions</p> <p>The vegetarian diet profile does not appear to adversely affect mood despite low intake of long-chain omega-3 fatty acids.</p