Howard walnut trees can be brought into bearing without annual pruning

In traditionally managed Howard walnut orchards, trees are pruned annually during the orchard development phase, an expensive operation in terms of labor and prunings disposal costs. Our observations and some prior research by others had suggested that pruning may not be necessary in walnut. In a trial of pruned and unpruned hedgerow trees over 8 years, beginning a year after planting, we documented canopy growth, tree height, yield and nut quality characteristics and also the effects of fruit removal. Pruning altered canopy shape but did not lead to increases in canopy development, yield or nut quality. Although fruit removal stimulated more vegetative growth in both the pruned and unpruned treatments, fruit removal did not result in an increase in midday canopy photosynthetically active radiation interception or cumulative yield when fruit removal was stopped after year 4. After 8 years, there were no significant differences in tree height, nut quality or cumulative yield among any of the treatments, which suggests that not pruning young Howard orchards could provide a net benefit to growers

The Vehicle, 1967, Vol. 10 no. 1

Vol. 10, No. 1 Table of Contents Christy Bowercover Photographpage 4 The CityCatherine Waitepage 4 A New DealAnonymouspage 5 The Penny Ride of Carnation PinkAstaire Pappaspage 8 RapeSharon Nelsonpage 10 Born AgainCharles J. Mertzpage 10 DrawingRourkepage 11 UntitledRourkepage 11 DialogueMolly Evanspage 12 SeldomJamse Jonsepage 12 The DifferenceDennis Muchmorepage 13 First LoveBruce Czeluscinskipage 15 Photographpage 15 Immorality of Troilus and Criseyde Milo S. Metcalfpage 16 Answer UnknownDave Owenpage 20 I Am LostJean Lacypage 21 Photographpage 22 On the Eve of No TomorrowsJane Careypage 23 Unrelated TwinsByron Nelsonpage 24 if i sitRoger Zulaufpage 25 if i sitDennis Muchmorepage 26 Drawingpage 27 Bibliographypage 28https://thekeep.eiu.edu/vehicle/1015/thumbnail.jp

Immune-mediated competition in rodent malaria is most likely caused by induced changes in innate immune clearance of merozoites

Malarial infections are often genetically diverse, leading to competitive interactions between parasites. A quantitative understanding of the competition between strains is essential to understand a wide range of issues, including the evolution of virulence and drug resistance. In this study, we use dynamical-model based Bayesian inference to investigate the cause of competitive suppression of an avirulent clone of Plasmodium chabaudi (AS) by a virulent clone (AJ) in immuno-deficient and competent mice. We test whether competitive suppression is caused by clone-specific differences in one or more of the following processes: adaptive immune clearance of merozoites and parasitised red blood cells (RBCs), background loss of merozoites and parasitised RBCs, RBC age preference, RBC infection rate, burst size, and within-RBC interference. These processes were parameterised in dynamical mathematical models and fitted to experimental data. We found that just one parameter μ, the ratio of background loss rate of merozoites to invasion rate of mature RBCs, needed to be clone-specific to predict the data. Interestingly, μ was found to be the same for both clones in single-clone infections, but different between the clones in mixed infections. The size of this difference was largest in immuno-competent mice and smallest in immuno-deficient mice. This explains why competitive suppression was alleviated in immuno-deficient mice. We found that competitive suppression acts early in infection, even before the day of peak parasitaemia. These results lead us to argue that the innate immune response clearing merozoites is the most likely, but not necessarily the only, mediator of competitive interactions between virulent and avirulent clones. Moreover, in mixed infections we predict there to be an interaction between the clones and the innate immune response which induces changes in the strength of its clearance of merozoites. What this interaction is unknown, but future refinement of the model, challenged with other datasets, may lead to its discovery

Securing Our Economic Future

The American economy is in the midst of a wrenching crisis, one caused by the COVID-19 pandemic and aggravated further by a series of climate-driven natural disasters. While the economy has made some steps towards recovery, the pandemic has laid bare the reality that too many Americans are unable to meet many of their urgent and basic needs. At the same time, it has become painfully clear that American society is not equipped to deal with the risks emerging from our changing climate. This book is a contribution towards policy options for addressing these challenges. Although it was largely written before the pandemic crises beset our country, the analyses, diagnoses, and prescriptions contained within all shed new light on the underlying fragilities that have since been exposed. The volume is composed of nine commissioned chapters and is divided into three sections, covering the 'Economics of the American Middle Class'; the 'Geographic Disparities in Economic Opportunity'; and the 'Geopolitics of the Climate and Energy Challenge and the US Policy Response.' Part I focuses on the economic wellbeing of the American middle class and the chapters in this section evaluate the prevailing narrative of its decline. The chapters in part II investigate the large variation in income and economic opportunities across places, and include a specific policy proposal for emergency rental assistance. Part III is devoted to the global climate crisis. The chapters in this final section emphasize the mounting social and economic costs of inaction and discuss potential policy approaches for tackling the climate challenge

Grazing livestock are exposed to terrestrial cyanobacteria

While toxins from aquatic cyanobacteria are a well-recognised cause of disease in birds and animals, exposure of grazing livestock to terrestrial cyanobacteria has not been described. This study identified terrestrial cyanobacteria, predominantlyPhormidiumspp., in the biofilm of plants from most livestock fields investigated. Lower numbers of other cyanobacteria, microalgae and fungi were present on many plants. Cyanobacterial 16S rDNA, predominantly fromPhormidiumspp., was detected in all samples tested, including 6 plant washings, 1 soil sample and ileal contents from 2 grazing horses. Further work was performed to test the hypothesis that ingestion of cyanotoxins contributes to the pathogenesis of some currently unexplained diseases of grazing horses, including equine grass sickness (EGS), equine motor neuron disease (EMND) and hepatopathy.Phormidiumpopulation density was significantly higher on EGS fields than on control fields. The cyanobacterial neurotoxic amino acid 2,4-diaminobutyric acid (DAB) was detected in plant washings from EGS fields, but worst case scenario estimations suggested the dose would be insufficient to cause disease. Neither DAB nor the cyanobacterial neurotoxins β-N-methylamino-L-alanine and N-(2-aminoethyl) glycine were detected in neural tissue from 6 EGS horses, 2 EMND horses and 7 control horses.Phormidiumwas present in low numbers on plants where horses had unexplained hepatopathy. This study did not yield evidence linking known cyanotoxins with disease in grazing horses. However, further study is warranted to identify and quantify toxins produced by cyanobacteria on livestock fields, and determine whether, under appropriate conditions, known or unknown cyanotoxins contribute to currently unexplained diseases in grazing livestock

Yield in almond is related more to the abundance of flowers than the relative number of flowers that set fruit

Almond tree yield is a function of the number of flowers on a tree and the percentage of flowers that set fruit. Almonds are borne on spurs (short proleptic shoots that can have both leaves and flowers). Almond tree spur dynamics research has documented that previous year spur leaf area is a predictive parameter for year-to-year spur survival, spur flowering and to a lesser extent spur fruiting, while previous year fruit bearing has a negative impact on subsequent year flowering. However, a question remained about whether yields are more dependent on flower numbers or relative fruit set of the flowers that are present. The aim of the present work was to compare the importance of flower abundance with that of relative fruit set in determining the productivity of a population of tagged spurs in almond trees over a 6-year period. Overall tree yield among years was more sensitive to total number of flowers on a tree rather than relative fruit set. These results emphasize the importance of maintaining large populations of healthy flowering spurs for sustained high production in almond orchards