bluuebunny/crossref_metadata_2025 huggingface dataset:
Does smoking affect the quality of bone regenerate in paediatric limb reconstructive surgery?
Authors: Rajan Rohan Ananda , Ong Ming , Jones Stanley , Fernandes James
Published: November 2007

Purpose

To bring to the attention of the orthopaedic fraternity that adolescent children smoke and this has an adverse effect on the bone regenerate during limb deformity corrective surgery.

Methods

Retrospective review of patients undergoing limb deformity corrective surgery with a prolonged frame time and bone-healing index. Patients operated on between 1993 and 2005 in a single regional specialist paediatric orthopaedic hospital.

Results

Seventeen smoking patients (16 adolescent, one aged 9 years), with prolonged bone regenerate consolidation time of more than double the standard time. Bone-healing index (BHI) was increased in both active smokers and passive smokers.

Conclusions

In the older child/adolescent we should consider smoking (active or passive) as a detrimental factor in prolonging their frame times. We should council these patients and their carers to stop smoking at least during the period of their treatment.
Evaluation and improvement of sticky traps as monitoring tools for Glossina austeni and G. brevipalpis (Diptera: Glossinidae) in north-eastern KwaZulu-Natal, South Africa
Authors: Green K. Kappmeier , Venter G.J.
Published: November 2007

The attractiveness of various colours, colour combinations and sizes of sticky traps of the 3-dimensional trap (3DT), cross-shaped target (XT), rectangular screen (RT) and monopanels were evaluated for their efficacy to capture Glossina austeni Newstead and G. brevipalpis Newstead in north-eastern KwaZulu-Natal, South Africa. The 3-dimensional shapes of the XT and 3DT in light blue (l.blue) and white were significantly (ca. 3.1–6.9 times) better than the RT for G. austeni. On bicoloured XTs, G. austeni landed preferentially on electric blue (e.blue) (58%) and black (63%) surfaces when used with white; while for G. brevipalpis, significantly more landed on e.blue (60–66%) surfaces when used with l.blue, black or white surfaces. Increased trap size increased the catches of G. brevipalpis females and both sexes of G. austeni significantly. Temoocid and polybutene sticky materials were equally effective and remained durable for 2–3 weeks. The glossy shine of trap surfaces did not have any significant effect on the attraction and landing responses of the two species. The overall trap efficiency of the e.blue/l.blue XT was 23% for G. brevipalpis and 28% for G. austeni, and that of the e.blue/black XT was 16% for G. brevipalpis and 51% for G. austeni. Larger monopanels, painted e.blue/black on both sides, increased the catches of G. austeni females significantly by up to four times compared to the standard e.blue/black XT. This monopanel would be recommended for use as a simple and cost effective survey tool for both species in South Africa.
Temporal detection of Cry1Ab-endotoxins in coccinellid predators from fields ofBacillus thuringiensiscorn
Authors: Harwood J.D. , Samson R.A. , Obrycki J.J.
Published: November 2007

The area planted to genetically engineered crops has increased dramatically in the last ten years. This has generated many studies examining non-target effects of bioengineered plants expressingBacillus thuringiensisendotoxins. To date, most have focused on population-level effects in the field or laboratory evaluation of specific plant-herbivore or plant-herbivore-predator trophic pathways. Using a post-mortem enzyme-linked immunosorbent assay, we examined the uptake of Cry1Ab-endotoxins by predatory coccinellids and the importance of anthesis to this trophic pathway. AdultColeomegilla maculata,Harmonia axyridis,Cycloneda mundaandCoccinella septempunctatacontained low, but detectable, quantities of Bt-endotoxin when screened by ELISA. This was most evident inC. maculata, with 12.8% of 775 individuals testing positive for Cry1Ab-endotoxins. Interestingly, the presence of endotoxins in gut samples was not confined to periods around anthesis, but coccinellid adults tested positive two weeks before and up to ten weeks after pollen was shed, suggesting tri-trophic linkages in their food chain facilitates the transfer of endotoxins into higher-order predators. This contrasts with adultColeomegilla maculataentering overwintering sites where Bt-endotoxins were not detected in gut samples, indicating low levels of persistence of Cry1Ab-endotoxins within coccinellid predators. This study enhances our understanding of complex interactions between transgenic crops and non-target food webs, but further research is required to quantify the significance of specific trophic linkages in the field.
Suitability of two carbon dioxide-baited traps for mosquito surveillance in the United Kingdom
Authors: Hutchinson R.A. , West P.A. , Lindsay S.W.
Published: November 2007

Rapidly changing environments and an increase in human movement around the globe have contributed to a rise in new and emerging diseases, many of which are arthropod borne. The threat posed to the United Kingdom by such diseases is uncertain, and there is a real need to understand the distribution, seasonality and behaviour of potential vectors in the country. At present, there is no standard method for routine mosquito surveillance in the UK. Here we compared the catching efficiency of two carbon dioxide-baited traps, the CDC light trap and the MosquitoMagnet®Pro trap, for collecting British mosquitoes. Two of each type of trap were operated at four sites in central and southern England from June to September, 2003. To determine whether trap height affected collections, three light traps were operated at 1, 2.5 and 5 m above the ground in one site in 2004. Both types of trap were efficient at catching mosquitoes, collecting 5414 mosquitoes of 16 species. MosquitoMagnet®traps caught 2.7 times more mosquitoes than CDC light traps (P<0.001) and a wider range of species (16 species vs 11) than CDC light traps. Four to six times more femaleCulex pipienss.l. were collected in light traps at 5 m (P<0.001) compared with traps at lower heights. MosquitoMagnet®traps ran continuously for up to 8 weeks, whilst the battery of a CDC light trap had to be replaced every 24 hrs. Although MosquitoMagnets®collected more specimens and a greater range of mosquito species, they were considerably more expensive, prone to breakdown and incurred higher running costs than the CDC light traps. MosquitoMagnets®are useful tools for collecting mosquitoes during longitudinal surveys during the summer months, whilst CDC light traps are to be preferred for rapid assessments of the presence or absence of mosquitoes, particularly the important speciesCulex pipiens.
Population structure of the banana weevil, an introduced pest in the Canary Islands, studied by RAPD analysis
Authors: Magaña C. , Beroiz B. , Hernández-Crespo P. , Montes de Oca M. , Carnero A. , Ortego F. , Castañera P.
Published: November 2007

The banana weevil (BW),Cosmopolites sordidus(Coleoptera: Curculionidae), is one of the most important insect pests of bananas and plantains. The mobility and the origin of BW infestations at the Canary Islands (Tenerife, La Gomera and La Palma) have been analysed using Random Amplified Polymorphic DNA (RAPD) as molecular markers. Populations from Costa Rica, Colombia, Uganda and Madeira were also included for comparison. One hundred and fifteen reproducible bands from eight primers were obtained. The level of polymorphism in the populations from the Canary Islands (40–62%) was in the range of those found in other populations. Nei's genetic distances, pair-wise fixation index (FST) values indicate that the closest populations are Tenerife populations among themselves (Nei's genetic distance=0.054–0.100;FST=0.091–0.157) and Costa Rica and Colombia populations (Nei's genetic distance=0.049;FST=0.113). Our results indicate the existence of BW local biotypes with limited gene flow and affected by genetic drift. These results are compatible with a unique event of colonization at Tenerife; whereas, the outbreaks in La Gomera and La Palma may come from independent introductions. The Madeira population is phylogenetically and geographically closer to the Canary Islands populations, suggesting that it is the most likely source of the insects introduced in the Canary Islands.
Predicting the spatial distribution of Ochlerotatus albifasciatus (Diptera: Culicidae) abundance with NOAA imagery
Authors: Gleiser R.M. , Gorla D.E.
Published: November 2007

Ochlerotatus albifasciatus is a vector of western equine encephalomyelitis in Argentina and a nuisance mosquito affecting beef and dairy production. The objective of this study was to analyze whether environmental proxy data derived from 1 km resolution NOAA-AVHRR images could be useful as a rapid tool for locating areas with higher potential for Oc. albifasciatus activity at a regional scale. Training sites for mosquito abundance categories were 3.3×3.3 km polygons over sampling sites. Abundance was classified into two categories according to a proposed threshold for economic losses. Data of channels 1, 2, 4 and 5 were used to calculate five biophysical variables: normalized differences vegetation index (NDVI), land surface temperature, total precipitable water, dew point and vapour saturation deficit. A discriminant analysis correctly classified 100% of the areas predicted to be above or below the economic threshold of 2500 mosquitoes per night of capture, respectively. Components of the NDVI, the total precipitable water and the dew point temperature contributed most to the function value. The results suggest that environmental data derived from AVHRR-NOAA could be useful for rapidly identifying adequate areas for mosquito development or activity.
Ground beetle (Coleoptera: Carabidae) inventories: a comparison of light and pitfall trapping
Authors: Liu Y. , Axmacher J.C. , Li L. , Wang C. , Yu Z.
Published: November 2007

Carabid inventories gained via pitfall trapping were compared to manual samples from light towers. A comparison of the two methods indicated that pitfall traps recorded a significantly higher diversity of carabids and were efficient in indicating changes of habitat conditions. Nevertheless, this method failed to give near-complete inventories of all carabid species present. Manual sampling at light towers resulted in far greater sample sizes, and this method was particularly efficient in monitoring potential pest species, but again failed to record all species present. Both methods hence showed different strengths, and only a combination, potentially also including further sampling techniques, will enable the generation of complete species inventories.
Long-term patterns and feeding sites of southern green stink bug (Hemiptera: Pentatomidae) in Hawaii macadamia orchards, and sampling for management decisions
Authors: Wright M.G. , Follett P.A. , Golden M.
Published: November 2007

Southern green stink bug (Nezara viridula, Hemiptera: Pentatomidae) is a pest of macadamia nuts, causing pitting to kernels by feeding. In spite of its pest status, many aspects of the ecology of this insect in macadamia orchards are poorly understood. This study analyzes long-term N. viridula damage to macadamia nuts and investigates the extent to which damage to nuts occurs in the tree canopy, prior to nut-drop. We show that there are distinct seasonal peaks in damage detected after harvest and that, over six years of data collection, mean damage levels were fairly low, albeit with spikes in damage levels recorded. Sampling nuts at peak harvest periods from different strata in the trees and from the ground showed that incidence of damaged nuts within the canopy was typically half as high as on the fallen nuts. Damage to fallen nuts may have occurred prior to nut-drop, and continued to accumulate after nut-drop. These results show that management of N. viridula within macadamia canopies, as opposed to only on fallen nuts, is important. A sampling procedure and predictive model for estimating late-season damage based on early-season damage samples is provided. The model uses January and March damage measurements (based on samples with set level of accuracy), mean temperature and month of the year for which damage is predicted. Early-season damage of 6–10% predicts late-season damage levels that should justify N. viridula suppression based on the nominal threshold (13% damage) used by kernel processors to reject nuts based on damage.
Relative developmental and reproductive fitness associated with pyrethroid resistance in the major southern African malaria vector,Anopheles funestus
Authors: Okoye P.N. , Brooke B.D. , Hunt R.H. , Coetzee M.
Published: November 2007

The effect of pyrethroid resistance on the fitness of a laboratory strain ofAnopheles funestusoriginating from southern Mozambique was evaluated by comparing the developmental and reproductive characteristics of a pyrethroid resistant strain with an insecticide susceptible strain. Fitness was evaluated in terms of fecundity, fertility, egg production, developmental time and life stage progression and survival. Of the eggs laid by females of the resistant strain, 81.5% hatched while only 66.9% were recorded in the susceptible strain. The time from egg hatch to adult emergence was longer for the resistant strain (15.9 days) than the susceptible strain (15.2 days). A significantly higher proportion of eggs from the resistant strain (61.6%) survived to adulthood compared with those of the susceptible strain (49%). Fecundity and larval and pupal survival did not differ significantly between strains. Of spermathecae dissected from females of the resistant strain, 56.8% were fertilized compared to 52.6% from the susceptible strain. The proportion of females that successfully produced eggs was 43.3% and 23.3% for the resistant and susceptible strains respectively. Complete failure of larval hatch was recorded in 28.6% of susceptible strain families compared to 7.7% of resistant families. Our results show that pyrethroid resistance in southern AfricanAn. funestusdoes not incur any loss of fitness under laboratory conditions. These results suggest that the removal of pyrethroid insecticide selection pressure may not lead to a regression of resistance alleles in pyrethroid resistantAn. funestuspopulations in southern Africa.
Adverse effects of ivermectin on the dung beetles,Caccobius jessoensisHarold, and rare species,Copris ochusMotschulsky andCopris acutidensMotschulsky (Coleoptera: Scarabaeidae), in Japan
Authors: Iwasa M. , Maruo T. , Ueda M. , Yamashita N.
Published: November 2007

Effects of the antiparasitic drug, ivermectin, on the dung beetles,Caccobius jessoensisHarold, 1867 and the rare species,Copris ochusMotschulsky, 1860 andCopris acutidensMotschulsky, 1860 were studied in laboratory and field experiments in Hokkaido, Japan. Ivermectin was detected in dung from 1 to 21 or 28 days following treatment, with a peak on the first day after treatment in two pour-on administrations (500 μg kg−1), although there were considerable differences between the two peaks. InC. jessoensis, brood balls constructed by the female were not reduced in the dung of treated cattle except for seven days after treatment in experiment 2. Also, there was no significant difference in the mean weight of brood balls between dung from treated and control cattle. However, the emergence rates were significantly reduced in dung 1–3 days after treatment. In the field study, brood balls constructed byC. jessoensiswere more abundant in dung from treated cattle in experiment 1, but adult emergence was significantly reduced at one and seven days after treatments. Adult mortality ofC. ochusMotschulsky at 90 days after the beginning of rearing was 11.1% in dung from control cattle with 22 brood balls constructed, whereas it was 84% in dung from treated cattle with no brood balls and/or ovipositioning. Also, inC. acutidensMotschulsky, adult mortality at 90 days after the beginning of rearing was 3.6% in dung from control cattle with 13 brood balls constructed, whereas it was 94.1% in dung from treated cattle with no brood balls or ovipositioning. The environmental risk in the use of ivermectin during breeding period of dung beetles in pasture is discussed.
Influence of habitat pattern on orientation during host fruit location in the tomato fruit fly,Neoceratitis cyanescens
Authors: Brévault T. , Quilici S.
Published: November 2007

Fruit flies have evolved mechanisms using olfactory and visual signals to find and recognize suitable host plants. The objective of the present study was to determine how habitat patterns may assist fruit flies in locating host plants and fruit. The tomato fruit fly,Neoceratitis cyanescens(Bezzi), was chosen as an example of a specialized fruit fly, attacking plants of the Solanaceae family. A series of experiments was conducted in an outdoor field cage wherein flies were released and captured on sticky orange and yellow spheres displayed in pairs within or above potted host or non-host plants. Bright orange spheres mimicking host fruit were significantly more attractive than yellow spheres only when placed within the canopy of host plants and not when either within non-host plants or above both types of plants. Additional experiments combining sets of host and non-host plants in the same cage, or spraying leaf extract of host plant (bug weed) on non-host plants showed that volatile cues emitted by the foliage of host plants may influence the visual response of flies in attracting mature females engaged in a searching behaviour for a laying site and in assisting them to find the host fruit. Moreover, the response was specific to mature females with a high oviposition drive because starved mature females, immature females and males showed no significant preference for orange spheres. Olfactory signals emitted by the host foliage could be an indicator of an appropriate habitat, leading flies to engage in searching for a visual image.
Dieback and recovery in poplar and attack by the hornet clearwing moth, Sesia apiformis (Clerck) (Lepidoptera: Sesiidae)
Authors: Straw N.A. , Green G. , Williams D.T.
Published: November 2007

A survey of 801 poplar trees in central east England in 1999 demonstrated a correlation between crown dieback and infestation by hornet clearwing moth (Sesia apiformis), induced by a period of drought in 1995–1996. To determine whether trees colonised by S. apiformis would subsequently deteriorate and die or whether they could recover despite infestation and damage to the stem, all trees in the original survey were re-assessed in 2001, 2003 and 2005. The repeat surveys showed that trees with 70% or less crown dieback in 1999 replaced their canopy and generally improved by 2005, irrespective of the numbers of S. apiformis in the stem, whereas trees that had 75% or more crown dieback in 1999 either died or declined further. The presence of S. apiformis did not prevent tree recovery, and there was little evidence that infestation slowed the rate of recovery. Populations of S. apiformis, measured in terms of the numbers of adult emergence holes visible in the base of the trees, decreased between 2001 and 2005 at the same time as the amount of dieback visible in the canopy of the poplars markedly decreased. However, the fall in numbers of emergence holes at this time reflected a decline in larval establishment 2–3 years earlier, and indicated that the moth population had responded to a more rapid restoration in the internal state of the trees, which was not reflected immediately by the gradual replacement of dead branches and reduction in dieback symptoms.
Ladybird egg cluster size: relationships between species, oviposition substrate and cannibalism
Authors: Timms J.E.L. , Leather S.R.
Published: November 2007

The success or not of ladybirds as biological control agents is dependent on both their foraging behaviour and their individual survival rates. The former is a function of the habitats they utilise; the latter, a consequence of their reproductive strategy. Egg clustering was investigated in two ladybird species, Aphidecta obliterata, a conifer specialist, and Adalia bipunctata, an arboreal woodland generalist. The effect of oviposition substrate (filter papers vs. spruce needles) on clutch size and oviposition preference was also tested. Adalia bipunctata laid significantly more eggs than A. obliterata. The size of egg clusters laid by the two coccinellids varied between species and substrate types. Adalia bipunctata laid larger egg clusters than A. obliterata, with batches reaching a maximum size of 32 eggs on spruce and 41 eggs on paper, while those of A. obliterata contained a maximum of 5 eggs on spruce and 9 eggs on paper. Of the clusters laid by A. obliterata, 18.6% of those on paper and 21.4% of those on spruce contained only a single egg, whereas a minimum of two eggs per cluster were laid by A. bipunctata. Smaller clusters were laid on the spruce cuttings by both species when compared with those laid on the filter paper, but A. obliterata laid significantly more eggs on spruce than on the filter paper (77% vs. 23%), whilst A. bipunctata laid significantly more eggs on the filter paper (91%). It is suggested that coccinellid eggs are more likely to be washed off spruce needles than broad leaves and that, by laying smaller egg clusters on spruce, A. obliterata reduces this risk. Adalia bipunctata usually lays its eggs on the underside of broad leaved trees and thus does not face this risk and thus can lay larger egg clusters. No differences in cannibalism rates were found between the two species. These findings have implications for the use of ladybirds as biological control agents in spruce forests.
The South Sudan Defence Force: patriots, collaborators or spoilers?
Authors: Arnold Matthew B.
Published: November 2007

Despite stipulations in the Sudan's 2005 Comprehensive Peace Agreement (CPA) that all ‘other armed groups’ be demobilised by January 2006, the South Sudan Defence Force (SSDF) continued to maintain a significant armed presence in South Sudan. This paper analyses the dynamics of the organisation, the impact of its ongoing presence on the security situation and reconstruction efforts, and attempts by the government of South Sudan to counteract the SSDF from January to August 2006. It argues that the strategies implemented by the government to counter the SSDF were fairly successful in that there was no major return to conflict. However, it concludes that the SSDF's continued presence, while hindered, has the potential to spark a return to civil war.
White-collar fundamentalism: interrogating youth religiosity on Nigerian university campuses
Authors: Obadare Ebenezer
Published: November 2007

Home historically to a politically engaged youth sector, Nigeria has, over the past two decades, witnessed a growing incidence of religious extremism involving educated youth, especially within university campuses. For all its important ramifications, and despite the continued infusion of social and political activity in the country by religious impulse, this phenomenon has yet to receive a systematic or coherent treatment in the relevant literature. This paper aims to locate youthful angst displayed by Nigerian university students within the context of postcolonial anomie and the attendant immiseration of civil society. Youth religious extremism on Nigerian campuses reflects both young people's frustration with national processes, and their perceived alienation from modernity's ‘cosmopolitan conversation’.
When men do women's work: structural adjustment, unemployment and changing gender relations in the informal economy of Accra, Ghana
Authors: Overå Ragnhild
Published: November 2007

Economic crisis and structural adjustment in Ghana have put large numbers of formal sector employees and civil servants out of work. This informalisation process has gendered consequences. Unemployed people, rural–urban migrants and school-leavers of both genders seek employment in the urban informal economy, and increasingly take up ‘female’ occupations – particularly in retail trade. Overcrowding in women's economic domains thus occurs. This study examines the livelihood strategies of informally employed men and women in Accra. It is argued that gender ideologies regarding appropriate occupations for women and men are continuously adapted in response to a changing political economy. Thus, even if female traders face competition, declining returnsanda heavier dependency burden, frustration with government policies failing to create decent jobs (for men) is more prevalent than gender antagonism and ridicule of those who find gender-atypical ways of eking out a living.
Business success, Angola-style: postcolonial politics and the rise and rise of Sonangol
Authors: de Oliveira Ricardo Soares
Published: November 2007

This paper investigates a paradoxical case of business success in one of the world's worst-governed states, Angola. Founded in 1976 as the essential tool of the Angolan end of the oil business, Sonangol, the national oil company, was from the very start protected from the dominant (both predatory and centrally planned) logic of Angola's political economy. Throughout its first years, the pragmatic senior management of Sonangol accumulated technical and managerial experience, often in partnership with Western oil and consulting firms. By the time the ruling party dropped Marxism in the early 1990s, Sonangol was the key domestic actor in the economy, an island of competence thriving in tandem with the implosion of most other Angolan state institutions. However, the growing sophistication of Sonangol (now employing thousands of people, active in four continents, and controlling a vast parallel budget of offshore accounts and myriad assets) has not led to the benign developmental outcomes one would expect from the successful ‘capacity building’ of the last thirty years. Instead, Sonangol has primarily been at the service of the presidency and its rentier ambitions. Amongst other themes, the paper seeks to highlight the extent to which a nominal ‘failed state’ can be successful amidst widespread human destitution, provided that basic tools for elite empowerment (in this case, Sonangol and the means of coercion) exist to ensure the viability of incumbents.
How does neopatrimonialism affect the African state's revenues? The case of tax collection in Zambia
Authors: Soest Christian von
Published: November 2007

Following the neopatrimonialism paradigm, it can be hypothesised that in African states informal politics of the rulers infringe on the collection of taxes and in turn reduce state revenue. This article tests this proposition for the case of Zambia. Neopatrimonial continuity in the country is evidenced by three factors: the concentration of political power, the award of personal favours, and the misuse of state resources. Despite this continuity, the revenue performance increased considerably with the creation of the semi-autonomous Zambia Revenue Authority. Donor pressure has been the most important intervening variable accounting for this improvement. Yet, strengthening the collection of central state revenue has been consistent with a neopatrimonial rationale, and may even have fed neopatrimonialism overall, by providing increased resources for particularistic expenditure.
Impacts of Chinese imports and coping strategies of local producers: the case of small-scale footwear enterprises in Ethiopia
Authors: Gebre-Egziabher Tegegne
Published: November 2007

The footwear sector in Ethiopia is dominated by cheap imports from Asia, particularly from China. This has inflicted heavy impacts on the sector, and threatened its competitiveness in the domestic market. This study examines the impact of imports and coping strategies of firms to withstand the competition. Firm level data were gathered from micro, small and medium footwear enterprises. The findings revealed that Chinese shoes are superior in design, price and quality, with the result that they have taken over the domestic market. The impact of Chinese imports on local producers varied from downsizing, bankruptcy, loss of assets and property, to downgrading activities and informalising operations. Firms have pursued coping strategies that focused on improving design and quality, as well as lowering prices and profit margins. Coping strategies appear to be differentiated by size of firms, and have some association with the performance of firms. The ways forward for local producers should focus on collaborative engagements of stakeholders and government to overcome the competitive disadvantages of firms. Training, technology, quality control, benchmarking and reorganization of production should be designed as a package of intervention. In addition, strengthening local producers to engage in collective actions and promoting exports should also be given proper attention.
The Trolley Problem as a Problem for Libertarians
Authors: PINCIONE GUIDO
Published: November 2007

Many political libertarians argue, or assume, that negative moral duties (duties not to harm others) prevail over positive moral duties (duties to aid others), and that the legal system ought to reflect such pre-eminence. I call into question this strategy for defending a libertarian order. I start by arguing that a successful account of the well-known case of a runaway trolley that is about to kill five innocents unless a passer-by diverts it onto one innocent, killing him, should point to (i) the ex ante advantage to all six of being subject to a policy of redirection of runaway trolleys, and (ii) the causal structure of killing vs. letting-die choices. I then argue that this account of the trolley case entails that legal systems reflecting the relative stringency of negative and positive moral duties should uphold redistributive measures at odds with libertarianism. The assumption that the legal system ought to reflect, through non-causal routes, moral principles and their relative weights leads to either an ideal-theory (in Rawls's sense) assessment of libertarianism or a symbolic account of the relationships between morality and law. Libertarians should undermine this assumption if they hope to offer an all-things-considered case for free markets.
Character, Global and Local
Authors: WEBBER JONATHAN
Published: November 2007

Philosophers have recently argued that we should revise our understanding of character. An individual's behaviour is governed not by a set of ‘global’ traits, each elicited by a certain kind of situational feature, they argue, but by a much larger array of ‘local’ traits, each elicited by a certain combination of situational features. But the data cited by these philosophers support their theory only if we conceive of traits purely in terms of stimulus and response, rather than in the more traditional terms of inner mental items such as inclinations. We should not adopt the former conception, moreover, since doing so would impede pursuit of the ethical aims for which we need a theory of character, whereas retaining the latter conception will facilitate this pursuit. So we should not revise our understanding of character in the way proposed.
Sidgwick's Epistemology
Authors: DEIGH JOHN
Published: November 2007

This article concerns two themes in Bart Schultz's recent biography of Henry Sidgwick, Henry Sidgwick: Eye of the Universe. The first is the importance of Sidgwick's conflict over his religious beliefs to the development of his thinking in The Methods of Ethics. I suggest that, in addition to the characteristics of Methods that Schulz highlights, the work's epistemology, specifically, Sidgwick's program of presenting ethics as an axiomatic system on the traditional understanding of such systems, is due to the conflict. The second is the relative neglect into which Methods fell in the first part of the twentieth century, neglect Schultz attributes to changes in philosophical fashions and to the undue influence of the Bloomsbury literati on British intellectual culture. I suggest that there is a deeper explanation, which lies in Sidgwick's program of presenting ethics as an axiomatic system on the traditional understanding of such systems. Such programs, I argue, became obsolete in analytic philosophy owing to changes in how axiomatization in mathematics was understood that resulted initially from the rise of non-Euclidean geometries and ultimately from the collapse of Frege's and Russell's logicism.
Hume on Forgiveness and the Unforgivable
Authors: PETTIGROVE GLEN
Published: November 2007

Are torture and torturers unforgivable? The article examines this question in the light of a Humean account of forgiveness. Initially, the Humean account appears to suggest that torturers are unforgivable. However, in the end, I argue it provides us with good reasons to think that even torturers may be forgiven.
What Even Consequentialists Should Say About the Virtues
Authors: RUSSELL LUKE
Published: November 2007

InUneasy Virtue, Julia Driver advocates a consequentialist account of the virtues. In so far as her view is ‘psychologically minimalist’, Driver's account is superior to the psychologically rich theories of virtue offered by Aristotle, Hume and Kant. However, Driver is also committed to ‘instrumentalism’ about virtue: a trait is a virtue only if it has instrumental value. In contrast, I argue for a ‘disjunctive’ form of minimalism, according to which a character trait counts as a virtue if it has either instrumental or intrinsic value. The common intuitions about virtue that Driver takes to support her ‘instrumental minimalism’ actually fit better with disjunctive minimalism. Admittedly, disjunctive minimalism is a messy account of virtue. However, this messiness would be a problem only if we drew a tight connection between virtue and right action, and we have good independent reasons for thinking there is no such tight link.
Pairwise Comparison and Numbers Skepticism
Authors: HSIEH NIEN-HÊ , STRUDLER ALAN , WASSERMAN DAVID
Published: November 2007

In this article, we defend pairwise comparison as a method to resolve conflicting claims from different people that cannot be jointly satisfied because of a scarcity of resources. We consider Michael Otsuka's recent challenge that pairwise comparison leads to intransitive choices for the ‘numbers skeptic’ (someone who believes the numbers should not count in forced choices among lives) and Frances Kamm's responses to Otsuka's challenge. We argue that Kamm's responses do not succeed, but that the threat they are designed to meet is illusory. Once the method of pairwise comparison is understood in a manner consistent with its proposed use, the challenge disappears. In making this argument, we examine questions about the interpretation of pairwise comparison and maintain that it must be understood as a method for ensuring that decisions are justifiable from the perspective of each affected individual.
Parity, Clumpiness and Rational Choice
Authors: PETERSON MARTIN
Published: November 2007

Some philosophers believe that two objects of value can be ‘roughly equal’, or ‘on a par’, or belong to the same ‘clump’ of value in a sense that is fundamentally different from that in which some objects are ‘better than’, ‘worse than’, or ‘equally as good as’ others. This article shows that if two objects are on a par, or belong to the same clump, then an agent accepting a few plausible premises can be exploited in a money-pump. The central premise of the argument is that value is choice-guiding. If one object is more valuable than another, then it is not permitted to choose the less valuable object; and if two objects are equally valuable it is permitted to choose either of them; and if two objects are on a par or belong to the same clump it is also permitted to choose either of them.
Rule-consequentialism and Internal Consistency: A Reply to Card
Authors: HOOKER BRAD
Published: November 2007

Rule-consequentialism has been accused of either collapsing into act-consequentialism or being internally inconsistent. I have tried to develop a form of rule-consequentialism without these flaws. In this June's issue of Utilitas, Robert Card argued that I have failed. Here I assess his arguments.
The accretion disk paradigm for young stars
Authors: Bertout Claude
Published: November 2007

Accretion and magnetic fields play major roles in several of the many models put forward to explain the properties of T Tauri stars since their discovery by Alfred Joy in the 1940s. Early investigators already recognized in the 1950s that a source of energy external to the star was needed to account for the emission properties of these stars in the optical range.

The opening of new spectral windows from the infrared to the ultraviolet in the 1970s and 1980s showed that the excess emission of T Tauri stars and related objects extends into all wavelength domains, while evidence of outflow and/or infall in their circumstellar medium was accumulating.

Although the disk hypothesis had been put forward by Merle Walker as early as 1972 to explain properties of YY Orionis stars and although Lynden-Bell and Pringle worked out the accretion disk model and applied it specifically to T Tauri stars in 1974, the prevailing model for young stellar objects until the mid-1980s assumed that they experienced extreme solar-type activity. It then took until the late 1980s before the indirect evidence of disks presented by several teams of researchers became so compelling that a paradigm shift occurred, leading to the current consensual picture.

I briefly review the various models proposed for explaining the properties of young stellar objects, from their discovery to the direct observations of circumstellar disks that have so elegantly confirmed the nature of young stars. I will go on to discuss more modern issues concerning their accretion disk properties and conclude with some results obtained in a recent attempt to better understand the evolution of Taurus-Auriga young stellar objects.
Measurements of magnetic fields on T Tauri stars
Authors: Johns–Krull Christopher M.
Published: November 2007

Stellar magnetic fields including a strong dipole component are believed to play a critical role in the early evolution of newly formed stars and their circumstellar accretion disks. It is currently believed that the stellar magnetic field truncates the accretion disk several stellar radii above the star. This action forces accreting material to flow along the field lines and accrete onto the star preferentially at high stellar latitudes. It is also thought that the stellar rotation rate becomes locked to the Keplerian velocity near the radius where the disk is truncated. This paper reviews recent efforts to measure the magnetic field properties of low mass pre-main sequence stars, focussing on how the observations compare with the theoretical expectations. A picture is emerging indicating that quite strong fields do indeed cover the majority of the surface on these stars; however, the dipole component of the field appears to be alarmingly small. On the other hand, at least one accretion model which takes into account the non-dipole nature of the magnetic field provides predictions relating various stellar and accretion parameters which are present in the current data.
Magnetic field at the inner disk edge
Authors: Jardine Moira , Gregory Scott G. , Donati Jean-François
Published: November 2007

Our present understanding of the coronal structure of T Tauri stars is fragmentary and observations in different wavelength regimes often appear to give contradictory results. X-ray data suggest the presence of magnetic loops on a variety of scales, from compact loops of size less than a stellar radius, up to very large loops of up to 10 stellar radii which may connect to the disk. While some stars show a clear rotational modulation in X-rays, implying distinct bright and dark regions, many do not. This picture is complicated by the accretion process itself, which also contributes to the X-ray emission. The location of the inner edge of the accretion disk and the nature of the magnetic field there are still hotly-contested issues. Accretion indicators often suggest the presence of discrete accretion funnels. This has implications for the structure of the corona, as does the presence of an outflowing wind. All of these factors are linked to the structure of the magnetic field, which we are now beginning to unravel through Zeeman-Doppler imaging. In this review I will describe the present state of our understanding of the magnetic structure of T Tauri coronae and the impact this has during such an early evolutionary stage.
Submillimetre polarimetric observations of magnetic fields in star-forming regions
Authors: Curran Rachel L. , Chrysostomou Antonio , Matthews Brenda C.
Published: November 2007

Submillimetre imaging polarimetry is one of the most powerful tools at present for studying magnetic fields in star-forming regions, and the only way to gain significant information on the structure of these fields. We present analysis of the largest sample (to date) of both high- and low-mass star-forming regions observed using this technique. A variety of magnetic field morphologies are observed, with no single field morphology favoured. Both the continuum emission morphologies and the field morphologies are generally more complex for the high-mass sample than the low-mass sample. The large scale magnetic field (observed with the JCMT; 14″ resolution) of NGC1333 IRAS2 is interpreted to be weak (compared to the energetic contributions due to turbulence) from the random field pattern observed. On smaller scales (observed with the BIMA array; 3″ resolution) the field is observed to be almost radial, consistent with the polarisation nulls in the JCMT data – suggesting that on smaller scales, the field may be more important to the star formation process. An analysis of the magnetic field direction and the jet/outflow axis is also discussed. Cumulative distribution functions of the difference between the mean position angle of the magnetic field vectors and the jet/outflow axis reveal no correlation. However, visual inspection of the maps reveal alignment of the magnetic field and jet/outflow axis in 7 out of 15 high-mass regions and 3 out of 8 low-mass regions.
Time variable funnel flows
Authors: Alencar Silvia H. P.
Published: November 2007

Magnetospheric accretion models are the current consensus to explain the main observed characteristics of classical T Tauri stars. In recent years the concept of a static magnetosphere has been challenged by synoptic studies of classical T Tauri stars that show strong evidence for the accretion process to be dynamic on several timescales and governed by changes in the magnetic field configuration. At the same time numerical simulation results predict evolving funnel flows due to the interaction between the stellar magnetosphere and the inner disk region. In this contribution we will focus on the main recent observational evidences for time variable funnel flows and compare them with model predictions.
Radiative-transfer modelling of funnel flows
Authors: Harries Tim J.
Published: November 2007

Emission line profiles from pre-main-sequence objects accreting via magnetically-controlled funnel flows encode information on the geometry and kinematics of the material on stellar radius scales. In order to extract this information it is necessary to perform radiative-transfer modelling of the gas to produce synthetic line profiles. In this review I discuss the physics that needs to be included in such models, and the numerical methods and assumptions that are used to render the problem tractable. I review the progress made in the field over the last decade, and summarize the main successes and failures of the modelling work.
Measuring the physical conditions of accreting gas in T Tauri systems
Authors: Bary Jeffrey S. , Matt Sean P.
Published: November 2007

Hydrogen emission lines observed from T Tauri stars (TTS) are associated with the accretion/outflow of gas in these young star forming systems. Magnetospheric accretion models have been moderately successful at reproducing the shapes of several Hi emission line profiles, suggesting that the emission arises in the accretion funnels. Despite considerable effort to model and observe these emission features, the physical conditions of the gas confined to the funnel flows remain poorly constrained by observation. We conducted a mutli-epoch near-infrared spectroscopic survey of 16 actively accreting classical TTS in the Taurus-Auriga star forming region. We present an analysis of these simultaneously acquired line flux ratios of many Paschen and Brackett series emission lines, in which we compare the observed ratios to those predicted by the Case B approximation of hydrogen recombination line theory. We find that the line flux ratios for the Paschen and Brackett decrements as well as a comparison between Brγ and Paschen transitions agree well with the Case B models with T < 5000 K and ne ≈ 1010 cm−3.
Observations of accretion shocks
Authors: Ardila David R.
Published: November 2007

I review our current understanding of accretion shocks in classical T Tauri stars (CTTs), from a UV and X-ray perspective. The region of the accretion shock is a good candidate as a source of UV transition region lines from Li/Na-like ions, which are stronger in CTTs than in naked atmospheres. Disk gas captured by the stellar magnetic field produces a strong radiative shock upon falling on the stellar surface. Radiation from the shock creates a radiative precursor and heats the stellar surface resulting in a hot spot. Stellar and shock models indicate that unless the post-shock column is very large, it will be buried on the stellar photosphere. Models of the continuum emission produced by this configuration can roughly reproduce the observed excess spectra down to 1650 Å. Transition region lines in CTTs are broad, very variable, and present blueshifted, centered, and redshifted centroids. Detailed models of the line emission have so far failed to reproduce the fluxes, line shapes, and line ratios. High resolution X-ray line observations indicate the presence of larger amounts of cool plasma in CTTs with respect to WTTs. Observations of density sensitive line ratios of He-like ions suggest high plasma densities, as expected from lines originating in the accretion shock. For most stars, the interpretation of these ratios in terms of density remains equivocal due to the presence of the strong UV continuum.
On the origin of continuum and line emission in CTTSs
Authors: Lamzin S. A. , Romanova M. M. , Kravtsova A. S.
Published: November 2007

We calculated profiles of CIV, 1550Å, Si IV 1400Å, NV 1240Å and OVI 1035Å doublet lines using results of 3D MHD simulations of disc accretion onto young stars with a dipole magnetic field. It appeared that our calculations cannot reproduce the profiles of these lines observed (HST/GHRS-STIS and FUSE) in CTTSs spectra. We also found that the theory predicts much larger CIV 1550Å line flux than observed (up to two orders of magnitude in some cases) and argue that the main portion of accretion energy in CTTSs is liberated outside the accretion shock. We conclude that the reason of disagreement between the theory and observation is the strongly non-dipolar character of CTTS magnetic field near its surface.
Inner disk regions revealed by infrared interferometry
Authors: Malbet Fabien
Published: November 2007

I review the results obtained by long-baseline interferometry at infrared wavelengths on the innermost regions around young stars. These observations directly probe the location of the dust and gas in the disks. The characteristic sizes of these regions are found larger than previously thought. These results have motivated in part a new class of models of the inner disk structure. However the precise understanding of the origin of these low visibilities is still in debate. Mid-infrared observations have probed disk emission over a larger range of scales revealing mineralogy gradients in the disk. Recent spectrally resolved observations allow the dust and gas to be studied separately. The few results show that the Brackett gamma emission can find its origin either in a wind or in a magnetosphere but there are no definitive answers yet. In a number of cases, the very high spatial resolution seems to reveal very close companions. In any case, these results provide crucial information on the structure and physical properties of disks surrounding young stars especially as initial conditions for planet formation.