Image guidance during breast radiotherapy: A phantom dosimetry and radiation-induced second cancer risk study

Imaging procedures utilised for patient position verification during breast radiotherapy can add a considerable dose to organs surrounding the target volume on top of therapeutic scatter dose. This study investigated the dose from a breast kilovoltage cone-beam CT (kV-CBCT), a breast megavoltage fan-beam CT (MV-FBCT), and a TomoDirectTM breast treatment. Thermoluminescent dosimeters placed within a female anthropomorphic phantom were utilised to measure the dose to various organs and tissues. The contralateral breast, lungs and heart received 0.40 cGy, 0.45 cGy and 0.40 cGy from the kV-CBCT and 1.74 cGy, 1.39 cGy and 1.73 cGy from the MV-FBCT. In comparison to treatment alone, daily imaging would increase the contralateral breast, contralateral lung and heart dose by a relative 12%, 24% and 13% for the kV-CBCT, and 52%, 101% and 58% for the MV-FBCT. The impact of the imaging dose relative to the treatment dose was assessed with linear and linear-quadratic radiation-induced secondary cancer risk models for the contralateral breast. The additional imaging dose and risk estimates presented in this study should be taken into account when considering an image modality and frequency for patient position verification protocols in breast radiotherapy

Smallholder farmers' motivations for using Conservation Agriculture and the roles of yield, labour and soil fertility in decision making

Conservation Agriculture (CA) has been widely promoted as an agro-ecological approach to sustainable production intensification. Despite numerous initiatives promoting CA across Sub-Saharan Africa there have been low rates of adoption. Furthermore, there has been strong debate concerning the ability of CA to provide benefits to smallholder farmers regarding yield, labour, soil quality and weeding, particularly where farmers are unable to access external inputs such as herbicides. This research finds evidence that CA, using no external inputs, is most attractive among the very poor and that farmers are driven primarily by strong motivational factors in the key areas of current contention, namely yield, labour, soil quality and weeding time benefits. This study is the first to incorporate a quantitative socio-psychological model to understand factors driving adoption of CA. Using the Theory of Planned Behaviour (TPB), it explores farmers' intention to use CA (within the next 12 months) in Cabo Delgado, Mozambique where CA has been promoted for almost a decade. The study site provides a rich population from which to examine farmers' decision making in using CA. Regression estimates show that the TPB provides a valid model of explaining farmers' intention to use CA accounting for 80% of the variation in intention. Farmers' attitude is found to be the strongest predictor of intention. This is mediated through key cognitive drivers present that influence farmers' attitude such as increased yields, reduction in labour, improvement in soil quality and reduction in weeds. Subjective norm (i.e. social pressure from referents) and perceived behavioural control also significantly influenced farmers' intention. Furthermore, path analysis identifies farmers that are members of a Farmer Field School or participants of other organisations (e.g. savings group, seed multiplication group or a specific crop/livestock association) have a significantly stronger positive attitude towards CA with the poorest the most likely users and the cohort that find it the easiest to use. This study provides improved understanding relevant to many developing countries, of smallholder farmers' adoption dynamics related to CA, and of how farmers may approach this and other ‘new’ management systems

“Funerals aren’t nice but it couldn’t have been nicer”. The makings of a good funeral

There is growing comment in both academic and popular writing about the shape and content of funerals today, with general agreement that we are seeing marked changes with a growing trend towards secularisation and personalisation. Despite this, there is as yet relatively little systematic research on the topic. This article reports on a study funded by the Arts and Humanities Research Council UK into spirituality in contemporary funerals. This qualitative study centred around case studies of 46 funerals in the north of England and gathered data from observations of funeral arrangement meetings as well as the funeral and semi-structured interviews with bereaved families and funeral professionals. The way both sets of participants engaged with the funeral and its constituent elements in an active process of meaning-seeking, meaning-creating and meaning-taking was closely aligned with contemporary understandings of humanistic spirituality. There was, however, little evidence of adherence to formal religious belief systems or wider philosophical frameworks amongst the bereaved families but considerable evidence of drawing on religious tradition and specific beliefs to locate personal meaning-making. The authors conclude that the funeral remains a significant ceremonial event which is psycho-social-spiritual in character and purpose

Experimental constraints on CO2 and H2O in the Martian mantle and primary magmas

We present new data on the stability of hornblende in a Martian mantle composition, on CO2 solubility in iron-rich basaltic magmas, and on the solubility of H2O in an alkalic basaltic magma. These new data are combined with a summary of data from the literature to present a summary of the current state of our estimates of solubilities of H2O and CO2 in probable Martian magmas and the stability of hornblende in a slightly hydrous mantle. The new results suggest that hornblende stability is not sensitive to the Mg/(Mg+Fe) ratio (mg#) of the mantle, that is the results for terrestrial mantle compositions are similar to the more iron-rich Martian composition. Likewise, CO2 solubility in iron-rich tholeiitic basaltic magmas is similar to iron-poor terrestrial compositions. The solubility of H2O has been measured in an alkalic basaltic (basanite) composition for the first time, and it is significantly lower than predicted for models of water solubility in magmas. The lack of mg# dependence observed in hornblende stability and on CO2 solubility that in many cases terrestrial results can be applied to Martian compositions. This conclusion does not apply to other phenomena such as primary magma compositions and major mantle mineral mineralogy

The role of local orography on the development of a severe rainfall event over western Peninsular Malaysia: a case study

Severe rainfall events are common in western Peninsular Malaysia. They are usually short and intense, and occasionally cause flash floods and landslides. Forecasting these local events is difficult and understanding the mechanisms of the rainfall events is vital for the advancement of tropical weather forecasting. This study investigates the mechanisms responsible for a local heavy rainfall event on 2 May 2012 that caused flash floods and landslides using both observations and simulations with the limited-area high-resolution UK Met Office Unified Model (MetUM). Results suggest that previous day rainfalls over Peninsular Malaysia and Sumatra Island influenced the development of overnight rainfall over the Strait of Malacca by low-level flow convergence. Afternoon convection over the Titiwangsa mountains over Peninsular Malaysia then induced rainfall development and the combination of these two events influenced the development of severe convective storm over western Peninsular Malaysia. Additionally, anomalously strong low-level north-westerlies also contributed to this event. Sensitivity studies were carried out to investigate the influence of the local orography on this event. Flattened Peninsular Malaysia orography causes a lack of rainfall over the central part of Peninsular Malaysia and Sumatra Island and produces a weaker overnight rainfall over the Strait of Malacca. By removing Sumatra Island in the final experiment, the western and inland parts of Peninsular Malaysia would receive more rainfall, as this region is more influenced by the westerly wind from the Indian Ocean. These results suggest the importance of the interation between land masses, orography, low-level flow and the diurnal cycle on the development of heavy rainfall events

Managing for rainfall variability: effect of grazing strategy on cattle production in a dry tropical savanna

Rainfall variability is a challenge to sustainable and pro. table cattle production in northern Australia. Strategies recommended to manage for rainfall variability, like light or variable stocking, are not widely adopted. This is due partly to the perception that sustainability and profitability are incompatible. A large, long-term grazing trial was initiated in 1997 in north Queensland, Australia, to test the effect of different grazing strategies on cattle production. These strategies are: (i) constant light stocking (LSR) at long-term carrying capacity (LTCC); (ii) constant heavy stocking (HSR) at twice LTCC; (iii) rotational wet-season spelling (R/Spell) at 1.5 LTCC; (iv) variable stocking (VAR), with stocking rates adjusted in May based on available pasture; and (v) a Southern Oscillation Index (SOI) variable strategy, with stocking rates adjusted in November, based on available pasture and SOI seasonal forecasts. Animal performance varied markedly over the 10 years for which data is presented, due to pronounced differences in rainfall and pasture availability. Nonetheless, lighter stocking at or about LTCC consistently gave the best individual liveweight gain (LWG), condition score and skeletal growth; mean LWG per annum was thus highest in the LSR (113 kg), intermediate in the R/Spell (104 kg) and lowest in the HSR(86 kg). MeanLWGwas 106 kg in the VAR and 103 kg in the SOI but, in all years, the relative performance of these strategies was dependent upon the stocking rate applied. After 2 years on the trial, steers from lightly stocked strategies were 60-100 kg heavier and received appreciable carcass price premiums at the meatworks compared to those under heavy stocking. In contrast, LWG per unit area was greatest at stocking rates of about twice LTCC; mean LWG/ha was thus greatest in the HSR (21 kg/ha), but this strategy required drought feeding in four of the 10 years and was unsustainable. Although LWG/ha was lower in the LSR (mean 14 kg/ha), or in strategies that reduced stocking rates in dry years like the VAR(mean 18 kg/ha) and SOI (mean 17 kg/ha), these strategies did not require drought feeding and appeared sustainable. The R/Spell strategy (mean 16 kg/ha) was compromised by an ill-timed fire, but also performed satisfactorily. The present results provide important evidence challenging the assumption that sustainable management in a variable environment is unprofitable. Further research is required to fully quantify the long-term effects of these strategies on land condition and profitability and to extrapolate the results to breeder performance at the property level