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Australian conservation cropping systems are practiced on very large farms (approximately 3,000 ha) where herbicides are relied on for effective and timely weed control. In many fields, though, there are low weed densities (e.g., <1.0 plant 10 m−2) and whole-field herbicide treatments are wasteful. For fallow weed control, commercially available weed detection systems provide the opportunity for site-specific herbicide treatments, removing the need for whole-field treatment of fallow fields with low weed densities. Concern about the sustainability of herbicide-reliant weed management systems remain and there has not been interest in the use of weed detection systems for alternative weed control technologies, such as targeted tillage. In this paper, we discuss the use of a targeted tillage technique for site-specific weed control in large-scale crop production systems. Three small-scale prototypes were used for engineering and weed control efficacy testing across a range of species and growth stages. With confidence established in the design approach and a demonstrated 100% weed-control potential, a 6-m wide pre-commercial prototype, the “Weed Chipper,” was built incorporating commercially available weed-detection cameras for practical field-scale evaluation. This testing confirmed very high (90%) weed control efficacies and associated low levels (1.8%) of soil disturbance where the weed density was fewer than 1.0 plant 10 m−2 in a commercial fallow. These data established the suitability of this mechanical approach to weed control for conservation cropping systems. The development of targeted tillage for fallow weed control represents the introduction of site-specific, nonchemical weed control for conservation cropping systems.
The rocky shores of the north-east Atlantic have been long studied. Our focus is from Gibraltar to Norway plus the Azores and Iceland. Phylogeographic processes shape biogeographic patterns of biodiversity. Long-term and broadscale studies have shown the responses of biota to past climate fluctuations and more recent anthropogenic climate change. Inter- and intra-specific species interactions along sharp local environmental gradients shape distributions and community structure and hence ecosystem functioning. Shifts in domination by fucoids in shelter to barnacles/mussels in exposure are mediated by grazing by patellid limpets. Further south fucoids become increasingly rare, with species disappearing or restricted to estuarine refuges, caused by greater desiccation and grazing pressure. Mesoscale processes influence bottom-up nutrient forcing and larval supply, hence affecting species abundance and distribution, and can be proximate factors setting range edges (e.g., the English Channel, the Iberian Peninsula). Impacts of invasive non-native species are reviewed. Knowledge gaps such as the work on rockpools and host–parasite dynamics are also outlined.
The straw itch mite, Pyemotes tritici Lagrèze-Fossat and Montané (Acari: Pyemotidae), was discovered parasitising the goldspotted oak borer, Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae), an invasive exotic species to California, United States of America, and the Mexican goldspotted oak borer, Agrilus coxalis Waterhouse (Coleoptera: Buprestidae), during surveys for natural enemies for a classical biological control programme for A. auroguttatus. Pyemotes tritici caused low levels of mortality to each species of flatheaded borer, but it will likely not be a good candidate for a biological control programme because it is a generalist parasitoid with deleterious human health effects.
Resilience after a nuclear power plant or other radiation emergency requires response and recovery activities that are appropriately safe, timely, effective, and well organized. Timely informed decisions must be made, and the logic behind them communicated during the evolution of the incident before the final outcome is known. Based on our experiences in Tokyo responding to the Fukushima Daiichi nuclear power plant crisis, we propose a real-time, medical decision model by which to make key health-related decisions that are central drivers to the overall incident management. Using this approach, on-site decision makers empowered to make interim decisions can act without undue delay using readily available and high-level scientific, medical, communication, and policy expertise. Ongoing assessment, consultation, and adaption to the changing conditions and additional information are additional key features. Given the central role of health and medical issues in all disasters, we propose that this medical decision model, which is compatible with the existing US National Response Framework structure, be considered for effective management of complex, large-scale, and large-consequence incidents. (Disaster Med Public Health Preparedness. 2012;0:1-10)
In order to determine the impact of garlic on total cholesterol (TC), TAG levels, as well as LDL and HDL, and establish if any variables have an impact on the magnitude of this effect, a meta-analysis was conducted. A systematic literature search of MEDLINE, CINAHL and the Cochrane Database from the earliest possible date through to November 2007 was conducted to identify randomised, placebo-controlled trials of garlic that reported effects on TC, TAG concentrations, LDL or HDL. The weighted mean difference of the change from baseline (with 95 % CI) was calculated as the difference between the means in the garlic groups and the control groups using a random-effects model. Subgroup and sensitivity analyses were performed to determine the effects on type, brand and duration of garlic therapy as well as baseline TC and TAG levels, the use of dietary modification, and study quality on the meta-analysis's conclusions. Twenty-nine trials were included in the analysis. Upon meta-analysis garlic was found to significantly reduce TC ( − 0·19; 95 % CI − 0·33, − 0·06 mmol/l) and TAG ( − 0·11; 95 % CI − 0·19, − 0·06 mmol/l) but exhibited no significant effect on LDL or HDL. There was a moderate degree of statistical heterogeneity for the TC and TAG analyses. Garlic reduces TC to a modest extent, an effect driven mostly by the modest reductions in TAG, without appreciable LDL lowering or HDL elevation. Higher baseline line TC levels and the use of dietary modification may alter the effect of garlic on these parameters. Future studies should be conducted evaluating the impact of adjunctive garlic therapy with fibrates or statins on TAG concentrations.
Layer-by-layer films incorporating single-wall carbon nanotubes (SWNTs) with anionic or cationic coatings have been prepared. The process of self-assembly was monitored using the quartz microbalance technique, while the morphology of the resulting thin layers was studied with atomic force microscopy. A variety of different architectures have been built up. The dc conductivities of the thin films, in-plane and out-of-plane, were measured at room temperature and contrasted with reference architectures. The results show clearly that the incorporation of SWNTs into the multilayers resulted in electrically conductive thin films.
The search for extraterrestrial habitable planets will require long observation times and the intelligent selection of appropriate parent stars and target biosignatures. While life can certainly develop in the absence of photosynthesis, such life forms on earth exhibit metabolic rates several orders of magnitude less than the activity accompanying a photosynthetic-driven ecosystem. The most accessible spectral biosignatures are those accompanying a system driven away from thermodynamic equilibrium by photosynthetic activity. For example, the co-existence in a planetary atmosphere of significant amounts of ozone, oxygen, and methane would be a strong indication of biotic activity. Investigating the issue of the Habitable Zone from the standpoint of the constraints inherent in photosynthesis it appears that the absorption characteristics of photosynthetic microorganisms on this planet make it likely that photosynthetic activity can exist on planets orbiting stars to red-ward of the Sun on the H-R diagram. Such a possibility is encouraging for terrestrial planet finder efforts since stars classified red-ward of our sun (G3 to K7) account for more than 55% of our nearest neighbors.
Modern colonialism, writes Gyan Prakash, ‘instituted enduring hierarchies of subjects and knowledges — the colonizer and the colonized, the Occidental and the Oriental, the civilized and the primitive, the scientific and the superstitious, the developed and the underdeveloped’. Such dichotomies ‘reduced complex differences and interactions to the binary (self/other) logic of colonial power’, and colonial rulers ‘constituted the “native” as their inverse image’. Such perceptions of difference as ‘other’ expressed what ‘civilized’ Westerners believed themselves not to be — but also what they feared they might become, should they lose rational self-control. The ‘other’, writes Eva Kornfelt, ‘threatens the integrity of the self by offering alternative, unrealized, and suppressed possibilities’. As shown by Western fascination with the ‘noble savage’, this process could sometimes produce positive representations. Yet even these expressed the needs of the perceiver rather than the reality of the perceived. ‘Othering’, then, is a complex process, one implying deep cultural and individual needs, which may occasionally result in accurate representations, but more often produces self-justifying positive/negative dichotomies.
Hundreds of American Indian children attended schools run by the Board of Foreign Missions (BFM) of the Presbyterian Church in the United States of America (PCUSA) during the nineteenth century. Yet these young Indians left little written evidence from which to reconstruct their responses to an alien educational experience. Presbyterian missionaries, on the other hand, sent detailed reports on the schools and pupils to headquarters in New York. If subjected to careful analysis, the admittedly partisan BFM writings are a rich source for discovering how Indian pupils responded to their teachers and to the whole BFM program.
Cerebrospinal fluid (CSF) from 20 chronically hospitalised male schizophrenics and from 12 patients admitted with acute schizophrenia were examined for antibodies against cytomegalovirus. A sensitive and specific enzyme-immunoassay was used to detect IgG or I g M classes of antibodies in the CSF of the schizophrenic patients and often orthopaedic patients, who served as controls. No significant amounts of I g M antibody were found in the CSF of either group. A significant titre of IgG was found in only one of the 32 schizophrenics, an acute patient, but in four of the orthopaedic patients. The results do not support an association of cytomegalovirus infection with schizophrenia; if such an association occurs, it must be unusual.