Global influences and local environments: Forestry and forest conservation in New Zealand, 1850s-1925.

This article examines the multiple factors that shaped the establishment of forest conservation and tree-planting in the colony of New Zealand. It presents a new perspective on forest history in New Zealand from the 1850s to the 1920s by examining the interplay of local and global factors in the development of forestry, while also suggesting future research topics in this area. Using the case-study of New Zealand, as an ancillary focus the article presents new interpretations of the exchange and introduction of forestry ideas, suggesting a need to re-examine the importance of locality in the period leading up to the emergence of ‘empire forestry’ in the twentieth century. With this in mind, it takes as one of its perspectives the work of historian of science David Livingstone, who has emphasised the importance of local factors in shaping the spread of scientific ideas. In light of Livingstone’s ideas, we demonstrate that while it makes sense to consider New Zealand forest policy both nationally and internationally, there were also significant local variations in policy according to geography, politics and other factors. These included uneven forest distribution throughout the country, slower growth-rates of indigenous trees and the impact of geography on forest removal and conservation. As well, long-standing political aversion to government interference in society restricted the role of the state in active forest management, giving greater latitude to private tree-planters. Meanwhile, New Zealand’ smaller government and population offered greater power to individuals than perhaps would be open to those living in larger societies with bigger government bureaucracies

An approach to the parametric design of ion thrusters

A methodology that can be used to determine which of several physical constraints can limit ion thruster power and thrust, under various design and operating conditions, is presented. The methodology is exercised to demonstrate typical limitations imposed by grid system span-to-gap ratio, intragrid electric field, discharge chamber power per unit beam area, screen grid lifetime, and accelerator grid lifetime constraints. Limitations on power and thrust for a thruster defined by typical discharge chamber and grid system parameters when it is operated at maximum thrust-to-power are discussed. It is pointed out that other operational objectives such as optimization of payload fraction or mission duration can be substituted for the thrust-to-power objective and that the methodology can be used as a tool for mission analysis

Can Oecophylla smaragdina be used to suppress incidence of CVPD in citrus orchards in Indonesia?

Citrus vein phloem degeneration (CVPD) is the Indonesian name for the Asian form of the devastating and incurable citrus disease known internationally as huánglóngbìng. It is associated with a phloem-limited pathogen, 'Candidatus Liberibacter asiaticus' (CLas) and transmitted by the Asiatic citrus psyllid (ACP), Diaphorina citri. ACP originated in South Asia but was first observed on citrus in 1900 in Java to where it may have been introduced decades earlier on lemon or lime seedlings brought from South Asia to reduce the incidence of scurvy among European sailors and in colonial settlements. CLas appears to have been introduced to the Pasar Minggu area of Jakarta in the 1940s from southern China, after it was introduced to Guangzhou, directly or indirectly, from South Asia in the late 1920s-early 1930s. Minimising incidence of the disease relies on planting pathogen-free trees, removal of infected trees, and unstainable use of synthetic pesticides that do not prevent spread of the disease. Parasitoids and predators of ACP are killed by the pesticides. Evidence from China and Viátnam suggests that effective management of the disease may be feasible if the weaver ant (semut rangrang), Oecophylla smaragdina, is deployed, cultivated, and managed in orchards

Macrophage transactivation for chemokine production identified as a negative regulator of granulomatous inflammation using agent-based modeling

Cellular activation in trans by interferons, cytokines and chemokines is a commonly recognized mechanism to amplify immune effector function and limit pathogen spread. However, an optimal host response also requires that collateral damage associated with inflammation is limited. This may be particularly so in the case of granulomatous inflammation, where an excessive number and / or excessively florid granulomas can have significant pathological consequences. Here, we have combined transcriptomics, agent-based modeling and in vivo experimental approaches to study constraints on hepatic granuloma formation in a murine model of experimental leishmaniasis. We demonstrate that chemokine production by non-infected Kupffer cells in the Leishmania donovani-infected liver promotes competition with infected KCs for available iNKT cells, ultimately inhibiting the extent of granulomatous inflammation. We propose trans-activation for chemokine production as a novel broadly applicable mechanism that may operate early in infection to limit excessive focal inflammation

Effect of Debonding in Fiber-Reinforced Compsites on Ultrasonic Backscattering

With the increased use of new high strength materials such as fiber-reinforced composites, the need for NDE methods is obvious, especially in industries such as the aerospace industry. The particular defect studied here (debonding of fiber from the matrix) is particularly important as it is often the earliest sign of fatigue damage in fiber-reinforced laminates [9]. Having an ability to detect such damage is clearly necessary and the application of ultrasound may provide a cheap and rapid method of detection. This paper presents two theoretical models of the effect of debonds on ultrasonic backscattering, and compares them with the experimental results from scale models of a single debonded fiber

A DigitalCAT: A Fusion of Creativity Assessment Theory and HCI

As a ‘gold standard’ creativity assessment method, it is important to reflect on the digital future of Amabile’s Consensual Assessment Technique (CAT). Over the past three decades, the CAT has given creativity researchers a formal tool on which to build a true science out of the subjective phenomenon of creativity in a vast range of domains. Research practice, however, has relied on primitive paper-based tools or only rudimentary digital technology. As a result, it is high time a more sophisticated, standardized research tool is developed to greatly facilitate future creativity research and assessment - a DigitalCAT - building on expertise from the design research, psychology and human-computer interaction (HCI) disciplines

Adapting to time: Duration channels do not mediate human time perception

Accurately encoding the duration and temporal order of events is essential for survival and important to everyday activities, from holding conversations to driving in fastflowing traffic. Although there is a growing body of evidence that the timing of brief events (< 1 s) is encoded by modality-specific mechanisms, it is not clear how such mechanisms register event duration. One approach gaining traction is a channel-based model; this envisages narrowly-tuned, overlapping timing mechanisms that respond preferentially to different durations. The channelbased model predicts that adapting to a given event duration will result in overestimating and underestimating the duration of longer and shorter events, respectively. We tested the model by having observers judge the duration of a brief (600 ms) visual test stimulus following adaptation to longer (860 ms) and shorter (340 ms) stimulus durations. The channel-based model predicts perceived duration compression of the test stimulus in the former condition and perceived duration expansion in the latter condition. Duration compression occurred in both conditions, suggesting that the channel-based model does not adequately account for perceived duration of visual events

Susceptibility of Diaphorina citri to irradiation with UV-A and UV-B and the applicability of the Bunsen–Roscoe reciprocity law

Populations of Diaphorina citri decline with elevation and, in a study in Bhutan, were rarely found above 1200 m ASL. The impact of ultraviolet (UV) radiation, particularly UV-B, on immature stages of the psyllid was proposed as limiting factor. As no studies have been undertaken on the influences of UV radiation on the development of D. citri, we examined the effects of UV-A and UVB on different stadia of the psyllid. In addition, compliance with the Bunsen–Roscoe reciprocity law was examined. Irradiation with UV-A marginally reduced egg hatch and the survival times of emerging nymphs. Early instar nymphs were little affected by this waveband, but the survival of adults was reduced at the higher doses used. With UV-B, egg hatch and the survival times of early and late instar nymphs declined in proportion to UV-B dose. A dose of 57.6 kJ m−2 d−1 reduced the survival time of only adult females. Female fecundity was reduced at high UV-A and UV-B doses but increased at low doses. The Bunsen–Roscoe law held true for eggs and early instar nymphs for different durations and irradiances of UV-B. Eggs and nymphs had ED50 values for UV-B lower than the daily fluxes of this wavelength experienced worldwide. Thus, UV-B could be a factor causing the psyllid to be scarce at high elevations

Discovery of Brassica yellows virus and porcine reproductive and respiratory syndrome virus in Diaphorina citri and changes in virome due to infection with ‘Ca. L. asiaticus’

Detection of new viruses or new virus hosts is essential for the protection of economically important agroecosystems and human health. Increasingly, metatranscriptomic data are being used to facilitate this process. Such data were obtained from adult Asian citrus psyllids (ACP) (Diaphorina citri Kuwayama) that fed solely on mandarin (Citrus _aurantium L.) plants grafted with buds infected with ?Candidatus Liberibacter asiaticus? (CLas), a phloem-limited bacterium associated with the severe Asian variant of huanglongbing (HLB), the most destructive disease of citrus. Brassica yellows virus (BrYV), the causative agent of yellowing or leafroll symptoms in brassicaceous plants, and its associated RNA (named as BrYVaRNA) were detected in ACP. In addition, the porcine reproductive and respiratory syndrome virus (PRRSV), which affects pigs and is economically important to pig production, was also found in ACP. These viruses were not detected in insects feeding on plants grafted with CLas-free buds. Changes in the concentrations of insect-specific viruses within the psyllid were caused by coinfection with CLas. IMPORTANCE The cross transmission of pathogenic viruses between different farming systems or plant communities is a major threat to plants and animals and, potentially, human health. The use of metagenomics is an effective approach to discover viruses and vectors. Here, we collected buds from the CLas-infected and CLas-free mandarin (Citrus aurantium L. [Rutaceae: Aurantioideae: Aurantieae]) trees from a commercial orchard and grafted them onto CLas-free mandarin plants under laboratory conditions. Through metatranscriptome sequencing, we first identified the Asian citrus psyllids feeding on plants grafted with CLas-infected buds carried the plant pathogen, brassica yellows virus and its associated RNA, and the swine pathogen, porcine reproductive and respiratory syndrome virus. These discoveries indicate that both viruses can be transmitted by grafting and acquired by ACP from CLas1 mandarin seedlings