bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnostic Value of Inflammation Markers in Predicting Perforation in Acute Sigmoid Diverticulitis
Authors: Käser S. A. , Fankhauser G. , Glauser P. M. , Toia D. , Maurer Christoph A.
Published: July 2010

Background

The importance of inflammation markers in predicting perforation in acute sigmoid diverticulitis is not well known. Predicting perforation by clinical examination alone may be hazardous. If perforation is suspected, then appropriate diagnostic tools such as computed tomography (CT) are indicated, and surgical intervention might be necessary.

Methods

A cohort of consecutive patients with acute sigmoid diverticulitis diagnosed by CT and with complete laboratory findings (n = 247) were retrospectively divided into two groups, one with perforation (n = 86) and another without (n = 161). The latest values of C‐reactive protein (CRP), white blood cell count (WBC), and serum bilirubin, as well as the activity of the alkaline phosphatase (AP) measured during the 48 h period before the CT scan, were assessed.

Results

In the Wilcoxon rank sum test CRP and WBC correlate significantly (p < 0.05) with perforation in acute sigmoid diverticulitis, whereas the logistic regression model shows only CRP to correlate significantly (p = 0.001) with perforation. The sensitivities/specificities for perforation are 98%/5% for elevated CRP (>5 mg/l), 86%/27% for a CRP higher than 50 mg/l, 44%/81% for a CRP higher than 150 mg/l, 28%/93% for a CRP higher than 200 mg/l, 88%/44% for elevated WBC (>10 × 109/l), 35%/90% for hyperbilirubinemia (>20 μmol/l), and 35%/91% for elevated AP (>110 U/l).

Conclusions

A CRP below 50 mg/l suggests a perforation to be unlikely in acute sigmoid diverticulitis, whereas a CRP higher than 200 mg/l is a strong indicator of perforation.
Marjolin’s Ulcers in sub‐Saharan Africa
Authors: Nthumba Peter M.
Published: July 2010

Background

Cutaneous malignancies are considered rare among Africans. Trauma, its sequelae, and other chronic non‐healing wounds are known to predispose to malignant degeneration. Not much is known of the demographics of Marjolin’s ulcers in sub‐Saharan Africa.

Methods

Pathology records on patients suspected to have Marjolin’s ulcers submitted to the Pathology Department were extracted from a database of 75,124 specimens. A review of the English literature on Marjolin’s ulcers from Nigeria, a sub‐Saharan country, was also performed.

Results

Of 210 specimens from suspected Marjolin’s ulcers, 167 records had a histological diagnosis of malignancy, with a male to female ratio of 1:1.4, and a mean age of 48 years (range: 4–97 years). There were 163 (97.6%) squamous cell carcinomas, 3 (1.8%) sarcomas, and 1 (0.6%) malignant melanoma. Burn scars, chronic ulcers, osteomyelitis, and “other” ulcers constituted 82 (49%), 70 (42%), 9 (5.4%), and 6 (3.6%), respectively. Subjects in six sub‐Saharan Marjolin’s ulcer studies had a mean age between 36 and 42 years, with a mean latent period 16 years.

Conclusions

Marjolin’s ulcers in sub‐Saharan African have a shorter latent period, and they occur in younger patients. Provision of early stable wound cover is essential for prevention of malignant degeneration of scars, while early appropriate intervention is crucial in the treatment of chronic ulcers.
Percutaneous Radiofrequency Ablation versus Partial Hepatectomy for Multicentric Small Hepatocellular Carcinomas: A Nonrandomized Comparative Study
Authors: Guo Wei‐Xing , Zhai Bo , Lai Eric C. H. , Li Nan , Shi Jie , Lau Wan‐Yee , Wu Meng‐Chao , Cheng Shu‐Qun
Published: July 2010

Background

The aim of this study was to compare the results of percutaneous radiofrequency ablation (RFA) with those of partial hepatectomy (PH) in the treatment of multicentric small hepatocellular carcinomas (HCCs). With advances in RFA, it is not known whether the minimally invasive approach with percutaneous RFA could attain comparable survival outcomes but with a lower morbidity in patients with multicentric HCCs.

Methods

From January 2002 and December 2007, 159 patients who had two or three HCCs, with the largest tumor no more than 5 cm in diameter, had no major vascular invasion or extrahepatic metastases, and were treated with either PH (n = 73) or RFA (n = 86) were included in the study.

Results

There was no procedure‐related mortality in both groups of patients. Major complications happened significantly more often after PH than after RFA (19.2 vs. 8.1%). The hospital stay was significantly longer after PH than after RFA (median = 9 vs. 3 days). The 1‐, 3‐, and 5‐year overall survival rates for the PH and RFA groups were 91.8, 68.7, 44.5% and 94.2, 64.4, 21.2%, respectively. The corresponding disease‐free survival rates for the two groups were 62.1, 33.6, 3.6% and 29.4, 2.7, 0%, respectively. The PH group had significantly longer overall survival and disease‐free survival than the RFA group.

Conclusions

PH resulted in better survival outcomes than RFA for patients with multicentric small HCCs. However, RFA had the benefits of lower procedure‐related morbidity and shorter hospital stay.
The choice of biomarkers determines the selenium status in young German vegans and vegetarians
Authors: Hoeflich Johanna , Hollenbach Birgit , Behrends Thomas , Hoeg Antonia , Stosnach Hagen , Schomburg Lutz
Published: July 2010

Daily nutrition varies considerably among individuals. The number of vegetarians is increasing continuously due to ethical, environmental, religious or other reasons. There is growing concern over their nutritional status with respect to micronutrient deficiencies. Among the essential trace elements, Se is of prime importance as it is part of the active site in selenoproteins. European soil and plants are relatively poor sources of Se, while farm animals are generally supplemented with Se in order to improve their health and avoid deficiency syndromes. We therefore wondered whether German vegetarians display a measurable Se deficiency. To this end, we compared young vegetarians (n 54) and omnivores (n 53). We assessed their Se status by measuring extracellular glutathione peroxidase 3 (GPX3) activity, and concentrations of total serum Se and circulating Se-transport protein selenoprotein P (SEPP). GPX3 activities were not different between the groups, whereas both total Se and SEPP concentrations were reduced to 79·5 and 71·2 % in vegetarians compared with omnivores. When splitting the group of vegetarians into vegans (n 26) and vegetarians consuming egg and milk products (n 28), analyses of the Se-dependent biomarkers did not reveal significant differences. We conclude that low serum Se is mirrored by circulating SEPP concentrations, but not by GPX3 activities in marginally supplied individuals. The specific dietary Se sources, divergent metabolic routes of selenomethionine v. selenocysteine and the different saturation kinetics of GPX3 and SEPP probably underlie our contradictory findings. Whether German vegetarians and vegans need to be considered as a Se-deficient group depends on the biomarker chosen.
DETERMINATION OF THRESHOLD REGIME OF SOIL MOISTURE TENSION FOR SCHEDULING IRRIGATION IN TROPICAL AEROBIC RICE FOR OPTIMUM CROP AND WATER PRODUCTIVITY
Authors: GHOSH A. , SINGH O. N.
Published: July 2010

Aerobic rice is considered a viable agro-technology to cope with the looming crisis of water supply that threatens the sustainability of irrigated rice production systems. Rice adapted to aerobic conditions requires less water than that grown under conventional irrigation management. A field study was conducted at Cuttack, India, during the dry season (January–May) in 2005 and 2006 to determine the critical soil moisture regime at the root-zone depth (30 cm) for sustaining optimum growth and grain yield of aerobic rice variety ‘Apo’ (IR 55423-01). Irrigation at 0, 20 and 40 kPa soil moisture tension resulted in similar grain yields (4.90–5.25 t ha−1 in 2005 and 4.35–4.50 t ha−1 in 2006). The seasonal water requirement in treatments receiving irrigation at 20, 40 and 60 kPa soil moisture tensions was 28.4, 42.8 and 60.7% lower than that at 0 kPa soil moisture tension, but the yield declined significantly at 60 kPa, i.e. by 42.8% in 2005 and 36.7% in 2006. Irrigation at 40 kPa soil moisture tension ensured maximum water productivity of 0.90, 0.47 and 0.53 g grain kg−1 water with respect to evapotranspiration, irrigation plus rainfall and irrigation alone, respectively. Thus, irrigation at 40 kPa soil moisture tension may be considered critical for optimum grain yield and maximum water productivity of aerobic rice in Indian cultivation conditions.
Geochemical and scintillometric characterization and correlation of amethyst geode-bearing Paraná lavas from the Quaraí and Los Catalanes districts, Brazil and Uruguay
Authors: HARTMANN LÉO A. , WILDNER WILSON , DUARTE LAUREN C. , DUARTE SANDRO K. , PERTILLE JULIANA , ARENA KARINE R. , MARTINS LAURA C. , DIAS NORBERTO LESSA
Published: July 2010

Geochemical studies of the six lowermost lava flows of the Cretaceous Serra Geral Formation (Paraná volcanic province) in Quaraí (Brazil) and Artigas (Uruguay) were combined with flow-by-flow field studies of structures and scintillometric profiles to establish a consistent regional stratigraphic framework over at least 100 km. This greatly improves exploration capability for amethyst and agate geodes. A basalt, colada Mata Olho (Alegrete facies, Serra Geral Formation), was the first lava to flow over the ancient Botucatu desert in the region, but an andesite, colada Catalán, overstepped this basalt in many places, perhaps palaeohighs. Four basaltic andesites complete the lava stratigraphy in this formation, adding up to 300 m of lavas. The stratigraphic sequence of contrasting lava compositions is 51.0 wt% SiO2 in the first lava, followed by 57.5, 52.5, 56.0, 53.0 and finally 54.5 wt% SiO2. Overall MgO variation is between 2 and 7 wt%. All lavas in the two districts are low-Ti (<2.0 wt% TiO2) of the Gramado type. The characteristic contents of most major and trace elements (124 rock samples analysed) allow the ready identification of each lava. Contrasting rock chemistry also results in strong variation in scintillometric values (270 points measured in the field and nineteen continuous borehole profiles); from bottom to top of the stratigraphy, the cps values are 49±3.2, 123±10.3, 62±4.7, 94±4.6, ~45 and ~85. Colada Catalán has the structure of aa lava, particularly the contorted igneous banding and autobreccias in the upper and lower crusts. In some places, a 2 m thick, silicified sandstone layer lies on top of some coladas, and silicified sandstone forms breccias with volcanic rocks. Geochemistry of the six lavas indicates complex evolution, involving melting of lithospheric mantle, injection into the crust and assimilation of crust followed by fractional crystallization. This study indicates the possibility of world-class deposits of amethyst geodes on the Brazilian side of the border with Uruguay.
Trade Competition and Domestic Pollution: A Panel Study, 1980–2003
Authors: Cao Xun , Prakash Aseem
Published: July 2010

This research note examines whether trade competition abets regulatory races in the environmental area. To analyze trade competition, we develop a new measure, structural equivalence, which assesses competitive threats that a country faces from other countries whose firms export the same products to the same destination countries. Employing this new measure, we analyze air pollution intensity (sulfur dioxide or SO2) and water pollution intensity (biochemical oxygen demand or BOD) for a panel of 140 countries for the time period 1980–2003. We find that trade competition is a significant predictor of water pollution intensity among structurally equivalent countries. We then test separately whether trade competition abets upward and downward regulatory races. We find that in the case of water pollution, countries respond symmetrically to downward and upward races, that is, they follow their structurally equivalent competitor countries both when they ratchet down their regulations and when they ratchet up regulations. In the case of air pollution, however, countries are responsive to downward policy changes only in competitor countries.
A Geography of Medical Knowledge: Country Doctors in Elizabeth Stuart Phelps and Sarah Orne Jewett
Authors: STOREY MARK
Published: July 2010

This essay examines two of the best-known postbellum representations of country doctors, Elizabeth Stuart Phelps's Doctor Zay (1882) and Sarah Orne Jewett's A Country Doctor (1884). While they have often been considered from a feminist point of view, this essay seeks both to complement and to argue against these existing readings by bringing a specifically geo-medical framework to bear on the texts. I consider both the thematic and the generic implications of representing country doctors in the postbellum era, exploring how they reflect, refract and encode the state of medical knowledge in postbellum America. I argue that literary representations of country doctors can contribute to an understanding of postbellum medical modernization by decentring it – by, in a sense, allowing us to comprehend the course of modern medical knowledge from a place usually assumed to remain outside modernity's transformations. Whilst I do, therefore, approach both these novels from a loosely new historicist perspective, I also want to think about how the social context they were engaging with determined, constrained and embedded itself into the thematic, formal and generic makeup of the novels themselves. Ultimately, this essay not only offers fresh readings of two important late nineteenth-century novels, but makes an intervention within the wider debates about nineteenth-century medical history and geography.
The search for a scientific temper: nuclear technology and the ambivalence of India's postcolonial modernity
Authors: CHACKO PRIYA
Published: July 2010

This article examines the relationship between India's nuclear programme and its postcolonial identity. In particular, I argue that making sense of the anomalies and contradictions of India's nuclear behaviour, such as the gap of two decades between its nuclear tests, its promotion of nuclear disarmament and its failure to sign non-proliferation and test-ban treaties requires an understanding of the racially gendered construction of India's postcolonial modernity and the central roles given to science and morality within it. I suggest that India's postcolonial identity is anchored in anticolonial discourses that are deeply ambivalent toward what was viewed as a Western modernity that could provide material betterment but was also potentially destructive. What was desired was a better modernity that took into account what was believed to be Indian civilisation's greater propensity toward ethical and moral conduct. India's nuclear policies, such as its pursuit of nuclear technology and its promotion of disarmament cannot be seen in isolation from the successes and failures of this broader project of fashioning an ethical modernity.
The German question in Central and Eastern Europe and the long peace in Europe after 1945: an integrated theoretical explanation
Authors: RYNHOLD JONATHAN
Published: July 2010

Within the field of International Relations, theoretically informed explanations of the long peace in Europe since 1945 tend to focus on Western Europe, especially the revolution in Franco-German relations. In contrast, German relations with Central and Eastern Europe (CEE) are ignored, despite the fact that this nexus was a major cause of instability prior to 1945. This article focuses on why the German question in CEE ceased to threaten the stability of Europe after 1945. The article empirically examines the development of the German question in CEE since 1945, which refers here mainly to the Oder-Neisse line and the plight of ethnic Germans expelled from CEE after World War II. It provides a theoretically integrated and chronologically sequenced explanation. First, it argues that Realism primarily explains the successful containment of the German question in CEE between 1945 and the late 1960s. Second, it argues that the Constructivist process of cultural change, which altered German intensions, was primarily responsible for subsequently increasing the depth of peace and stability between Germany and CEE, especially after the Cold War. Finally, it is argued that prior Realist factors and Liberal processes constituted a necessary, though not sufficient, condition for cultural change.
On modular signs
Authors: KOWALSKI E. , LAU Y.-K. , SOUNDARARAJAN K. , WU J.
Published: July 2010

We consider some questions related to the signs of Hecke eigenvalues or Fourier coefficients of classical modular forms. One problem is to determine to what extent those signs, for suitable sets of primes, determine uniquely the modular form, and we give both individual and statistical results. The second problem, which has been considered by a number of authors, is to determine the size, in terms of the conductor and weight, of the first sign-change of Hecke eigenvalues. Here we improve the recent estimate of Iwaniec, Kohnen and Sengupta.
XXXIII. On the Hindú Quadrature of the Circle, and the infinite Series of the proportion of the circumference to the diameter exhibited in the four S'ástras, the Tantra Sangraham, Yucti Bháshá, Carana Padhati, and Sadratnamála
Authors: Whish Charles M.
Published: July 2010

A'ryab'hatta, who flourished in the beginning of the thirty-seventh century of the Cáli Yuga, of which four thousand nine hundred and twenty years have passed, has in his work, the Aryab'hatiyam, in which he mentions the period of his birth, exhibited the proportion of the diameter to the circumference of the circle as 20000 to 62832, in the following verse:

Chaturadhicam ṣatamashṭaguṇandwáshashṭistathá sahasráṇám Ayutadwaya vishcambhasyásannó vritta pariṇáhah.
Healthy Eating Index during pregnancy according to pre-gravid and gravid weight status
Authors: Tsigga Maria , Filis Vlasios , Hatzopoulou Konstantina , Kotzamanidis Charalambos , Grammatikopoulou Maria G
Published: July 2010

Objective

To assess differences in the Healthy Eating Index (HEI) during pregnancy with the pre-gravid and gravid weight status of women.

Design

Cross-sectional.

Setting

Athens, Greece.

Subjects

One hundred pregnant women, inhabitants of Athens.

Results

The mean raw HEI score of the sample was 66·9 (sd 7·6) and the mean HEI adjusted for energy intake was 66·9 (sd 0·6). No difference was recorded between the adjusted HEI and different gravidities, the embryo’s sex, different income categories or education. When HEI was categorised as low, average and adequate, living in an urban residence increased the odds for demonstrating low HEI score (OR = 10·231, 95 % CI 1·300, 80·487). HEI score during pregnancy was significantly higher in participants who were either pre-gravidly underweight or of normal body weight (BW). In relation to the gestational weight status, the highest HEI scores and protein intake were shown in the underweight and of normal BW participants compared with the obese. According to the simple correspondence analysis, adequate HEI was associated with rural residence and being underweight or having normal BW during pregnancy. Low HEI was associated with overweight and obesity during pregnancy, with obesity before pregnancy and living in an urban environment. HEI was negatively correlated to the pre-conceptional and gestational BMI (r = −0·298, P ≤ 0·003 and r = −0·345, P ≤ 0·001) and to the week of gestation (r = −0·285, P ≤ 0·004).

Conclusions

Overall, the HEI of the sample was mediocre. Women who were underweight or of normal BW exhibited a better diet quality compared with obese women; thus the latter consist a population in greater need for supervised nutrition and dietary counselling during pregnancy.
Cereal consumption and indicators of cardiovascular risk in adolescent girls
Authors: Franko Debra L , Albertson Ann M , Thompson Douglas R , Barton Bruce A
Published: July 2010

Objective

To examine the association between cereal consumption and cardiovascular risk factors including waist, height, total cholesterol, LDL cholesterol and HDL cholesterol in a sample of adolescent girls.

Design

Longitudinal study.

Setting

The study was conducted from 1987 to 1997 and data were collected at three study sites (University of California at Berkeley, University of Cincinnati and Westat Inc., Rockville, MD, USA). Mixed models were used to estimate the association between the number of days of eating cereal and these four outcome variables.

Subjects

Girls (n2371) who participated in the 10-year National Heart, Lung, and Blood Growth and Health Study (NGHS) and completed a 3 d food diary in years 1–5 and 7, 8 and 10.

Results

Adolescent girls who ate cereal more often had lower waist-to-height ratio (P< 0·005), lower total cholesterol (P< 0·05) and lower LDL cholesterol (P< 0·05), taking into account sociodemographic variables, physical activity levels and total energy intake.

Conclusions

Findings suggest that cereal consumption is associated with markers of cardiovascular risk and that childhood patterns of consumption may influence the development of risk factors later in adolescence.
Romantic attachment in young adults with very low birth weight – The Helsinki Study of Very Low Birth Weight Adults
Authors: Pyhälä R. , Räikkönen K. , Pesonen A.-K. , Heinonen K. , Hovi P. , Järvenpää A.-L. , Eriksson J. G. , Andersson S. , Kajantie E.
Published: July 2010

Early attachment relationships from infancy onward contribute to attachment patterns later in life, to the ability to build up close relationships and to well-being in general. Severely preterm birth may challenge the development of these attachment relationships. We studied whether there are differences in attachment patterns related to romantic relationships between young adults (mean age 22.4 years, s.d. 2.2 years) with very low birth weight (VLBW, <1500 g; n = 162) and their peers born at term (n = 172), who completed the Experiences in Close Relationships Questionnaire – Revised. Young adults born at VLBW showed lower attachment-related anxiety than their peers born at term (mean difference −9.5%, 95% CI −16.0 to −2.6) when adjusted for sex, age, parental education and being in a romantic relationship currently. The groups did not differ in attachment-related avoidance. In subgroup analyses, the VLBW women born small for gestational age (SGA, birth weight <−2 s.d.) scored on average 14.8% (95% CI 3.1–26.6) higher than the control women on attachment avoidance. The effects remained after the exclusion of 18 participants with neurosensory deficits. We found no evidence for a compromised attachment pattern in young adults born at VLBW, with a possible exception of women born SGA at VLBW. VLBW adults were rather characterized by a lower level of attachment-related anxiety.
Coseismic and postseismic slip from the 2003 San Simeon earthquake and their effects on backthrust slip and the 2004 Parkfield earthquake
Authors: Johanson I. A. , Bürgmann R.
Published: July 2010

The 2003 M6.5 San Simeon earthquake occurred less than a year before and 50 km west of the long‐awaited Parkfield earthquake of 2004. Aftershocks of the San Simeon event occurred not only on the presumptive rupture plane but also delineated subconjugate structures to the east (backthrusts). InSAR data show a complex pattern of deformation during the postseismic time interval and suggest that shallow postseismic slip may have occurred on the backthrust structures. In this paper we present a model inversion for slip during and after the earthquake from four interferograms and GPS data. We find that the data are well‐fit when coseismic slip is allowed on two planes, the main rupture plane and a backthrust structure to the south. The backthrust structure accommodates slip amounting to about one third of the coseismic moment release. Shallow postseismic slip also occurred on the main rupture plane, updip from the coseismic slip, and on the southern backthrust. Postseismic slip on the more northern backthrust structure is not well‐constrained and the data is fit nearly as well without including it. The areas of postseismic slip on the backthrusts correspond well with areas that experienced unclamping and little slip is found in regions of clamping. No value for the coefficient of friction below 1.0 results in a Coulomb Failure Stress field that matches the aseismic slip distributions better than the normal stress alone. We also investigate whether static stress changes from the San Simeon earthquake acted to encourage right‐lateral strike slip on the Parkfield segment of the San Andreas fault. We find that the San Simeon earthquake's rupture planes were oriented in such a way that the maximum increase in Coulomb failure stress on the San Andreas fault occurred on the Parkfield segment. The 2004 Parkfield earthquake differed from its expected behavior by nucleating in the southern portion of the Parkfield segment; an area that experienced increased shear stress of 0.1–0.14 bars from coseismic slip in the San Simeon earthquake. Postseismic slip from San Simeon further loaded the southern portion of the Parkfield segment preferentially over the northern portion, though the size of the stress changes was small (0.03–0.04 bars).
It takes three to tango: 1. Simulating buoyancy‐driven flow in the presence of large viscosity contrasts
Authors: Suckale Jenny , Nave Jean‐Christophe , Hager Bradford H.
Published: July 2010

Buoyancy‐driven flow is of fundamental importance for numerous geodynamic phenomena. Since the equations of motion governing multiphase flow are rarely amenable to analytical solutions, numerical simulations provide a compelling alternative. They offer the ability to carefully analyze flow phenomena under differing regimes, initial conditions, and flow dynamics. The three key challenges in these computations are (1) the accurate solution of the equations of motion in the presence of large viscosity contrasts, (2) the representation of strongly deforming interfaces between different fluids, and (3) the accurate coupling of fluid and interface solver. In three dimensions, these challenges become even more intricate, and the appropriate choice of numerical scheme has a profound influence on the tractability, accuracy, robustness, and efficiency of the computational simulation. This is the first paper of two that examine numerical simulations of buoyancy‐driven flow in the presence of large viscosity contrasts. In this paper, we present our numerical approach which tackles the above three main challenges through a combination of three numerical methods, namely, (1) an extended ghost fluid type discretization which we developed specifically for the Stokes regime, (2) the level set method, and (3) the extension velocity technique. We find that all three components are crucial to obtain a versatile numerical tool for simulating complex structures in evolving flow. We validate our code by reproducing four benchmark problems in two and three dimensions. We devote special attention to comparing our method to other existing techniques, detailing the advantages of this approach. Finally, we highlight several types of geophysical flow problems for which we believe our method to be well suited.
A model for turbulent hydraulic fracture and application to crack propagation at glacier beds
Authors: Tsai Victor C. , Rice James R.
Published: July 2010

Glaciological observations of under‐flooding suggest that fluid‐induced hydraulic fracture of an ice sheet from its bed sometimes occurs quickly, possibly driven by turbulently flowing water in a broad sheet flow. Taking the approximation of a fully turbulent flow into an elastic ice medium with small fracture toughness, we derive an approximate expression for the crack‐tip speed, opening displacement and pressure profile. We accomplish this by first showing that a Manning‐Strickler channel model for resistance to turbulent flow leads to a mathematical structure somewhat similar to that for resistance to laminar flow of a power law viscous fluid. We then adapt the plane‐strain asymptotic crack solution of Desroches et al. (1994) and the power law self‐similar solution of Adachi and Detournay (2002) for that case to calculate the desired quantities. The speed of crack growth is shown to scale as the overpressure (in excess of ice overburden) to the power 7/6, inversely as ice elastic modulus to the power 2/3, and as the ratio of crack length to wall roughness scale to the power 1/6. We tentatively apply our model by choosing parameter values thought appropriate for a basal crack driven by the rapid drainage of a surface meltwater lake near the margin of the Greenland Ice Sheet. Making various approximations perhaps relevant to this setting, we estimate fluid inflow rate to the basal fracture and vertical and horizontal surface displacements and find order‐of‐magnitude agreement with observations by Das et al. (2008) associated with lake drainage. Finally, we discuss how these preliminary estimates could be improved.
Anthropogenic impacts on global storage and emissions of mercury from terrestrial soils: Insights from a new global model
Authors: Smith‐Downey Nicole V , Sunderland Elsie M. , Jacob Daniel J.
Published: July 2010

We develop a mechanistic global model of soil mercury storage and emissions that ties the lifetime of mercury in soils to the lifetime of the organic carbon pools it is associated with. We explore the implications of considering terrestrial mercury cycling in the framework of soil carbon cycling and suggest possible avenues of future research to test our assumptions and constrain this type of model. In our simulation, input of mercury to soil is by atmospheric deposition, in part through leaf uptake and subsequent litter fall, and is moderated by surface photoreduction and revolatilization. Once bound to organic carbon, mercury is transferred along a succession of short‐lived to long‐lived carbon pools and is ultimately reemitted by respiration of these pools. We examine the legacy of anthropogenic influence on global mercury storage and emissions and estimate that storage of mercury in organic soils has increased by ∼20% since preindustrial times, while soil emissions have increased by a factor of 3 (2900 Mg yr−1 versus 1000 Mg yr−1). At steady state, mercury accumulates in the most recalcitrant soil carbon pools and has an overall lifetime against respiration of 630 years. However, the impact of anthropogenic emissions since preindustrial times has been concentrated in more labile pools, so that the mean lifetime of present‐day anthropogenic mercury in all pools is ∼80 years. Our analysis suggests that reductions in anthropogenic emissions would lead to immediate and large reductions in secondary soil mercury emissions.
A microbial fuel cell in contaminated ground delineated by electrical self‐potential and normalized induced polarization data
Authors: Doherty R. , Kulessa B. , Ferguson A. S. , Larkin M. J. , Kulakov L. A. , Kalin R. M.
Published: July 2010

There is a growing interest in the use of geophysical methods to aid investigation and monitoring of complex biogeochemical environments, for example delineation of contaminants and microbial activity related to land contamination. We combined geophysical monitoring with chemical and microbiological analysis to create a conceptual biogeochemical model of processes around a contaminant plume within a manufactured gas plant site. Self‐potential, induced polarization and electrical resistivity techniques were used to monitor the plume. We propose that an exceptionally strong (>800 mV peak to peak) dipolar SP anomaly represents a microbial fuel cell operating in the subsurface. The electromagnetic and electrical geophysical data delineated a shallow aerobic perched water body containing conductive gasworks waste which acts as the abiotic cathode of microbial fuel cell. This is separated from the plume below by a thin clay layer across the site. Microbiological evidence suggests that degradation of organic contaminants in the plume is dominated by the presence of ammonium and its subsequent degradation. We propose that the degradation of contaminants by microbial communities at the edge of the plume provides a source of electrons and acts as the anode of the fuel cell. We hypothesize that ions and electrons are transferred through the clay layer that was punctured during the trial pitting phase of the investigation. This is inferred to act as an electronic conductor connecting the biologically mediated anode to the abiotic cathode. Integrated electrical geophysical techniques appear well suited to act as rapid, low cost sustainable tools to monitor biodegradation.
Elements of a computational infrastructure for social simulation
Authors: Birkin Mark , Procter Rob , Allan Rob , Bechhofer Sean , Buchan Iain , Goble Carole , Hudson-Smith Andy , Lambert Paul , De Roure David , Sinnott Richard
Published: July 2010

Applications of simulation modelling in social science domains are varied and increasingly widespread. The effective deployment of simulation models depends on access to diverse datasets, the use of analysis capabilities, the ability to visualize model outcomes and to capture, share and re-use simulations as evidence in research and policy-making. We describe three applications of e-social science that promote social simulation modelling, data management and visualization. An example is outlined in which the three components are brought together in a transport planning context. We discuss opportunities and benefits for the combination of these and other components into an e-infrastructure for social simulation and review recent progress towards the establishment of such an infrastructure.
A social science data-fusion tool and the Data Management through e-Social Science (DAMES) infrastructure
Authors: Warner Guy C. , Blum Jesse M. , Jones Simon B. , Lambert Paul S. , Turner Kenneth J. , Tan Larry , Dawson Alison S. F. , Bell David N. F.
Published: July 2010

The last two decades have seen substantially increased potential for quantitative social science research. This has been made possible by the significant expansion of publicly available social science datasets, the development of new analytical methodologies, such as microsimulation, and increases in computing power. These rich resources do, however, bring with them substantial challenges associated with organizing and using data. These processes are often referred to as ‘data management’. The Data Management through e-Social Science (DAMES) project is working to support activities of data management for social science research. This paper describes the DAMES infrastructure, focusing on the data-fusion process that is central to the project approach. It covers: the background and requirements for provision of resources by DAMES; the use of grid technologies to provide easy-to-use tools and user front-ends for several common social science data-management tasks such as data fusion; the approach taken to solve problems related to data resources and metadata relevant to social science applications; and the implementation of the architecture that has been designed to achieve this infrastructure.
Ecological genetics of sex ratios in plant populations
Authors: Barrett Spencer C. H. , Yakimowski Sarah B. , Field David L. , Pickup Melinda
Published: July 2010

In many angiosperm species, populations are reproductively subdivided into distinct sexual morphs including females, males and hermaphrodites. Sexual polymorphism is maintained by frequency-dependent selection, leading to predictable sex ratios at equilibrium. Charles Darwin devoted much of his book ‘The Different Forms of Flowers on Plants of the Same Species’ (1877) to investigating plant sexual polymorphisms and laid the foundation for many problems addressed today by integrating theory with empirical studies of the demography and genetics of populations. Here, we summarize our recent work on the ecological and genetic mechanisms influencing variation in sex ratios and their implications for evolutionary transitions among sexual systems. We present the results of a survey of sex ratios from 126 species from 47 angiosperm families and then address two general problems using examples from diverse angiosperm taxa: (i) the mechanisms governing biased sex ratios in dioecious species; (ii) the origins and maintenance of populations composed of females, males and hermaphrodites. Several themes are emphasized, including the importance of non-equilibrium conditions, the role of life history and demography in affecting sex ratios, the value of theory for modelling the dynamics of sex ratio variation, and the utility of genetic markers for investigating evolutionary processes in sexually polymorphic plant populations.
Microbial secretor–cheater dynamics
Authors: Frank Steven A.
Published: July 2010

Microbial secretions manipulate the environment and communicate information to neighbours. The secretions of an individual microbe typically act externally and benefit all members of the local group. Secreting imposes a cost in terms of growth, so that cheaters that do not secrete gain by sharing the benefits without paying the costs. Cheaters have been observed in several experimental and natural settings. Given that cheaters grow faster than secretors when in direct competition, what maintains the widely observed patterns of secretion? Recent theory has emphasized the genetic structure of populations, in which secretors tend to associate spatially with other secretors, reducing direct competition and allowing highly secreting groups to share mutual benefits. Such kin selection can be a powerful force favouring cooperative traits. Here, I argue that, although kin selection is a factor, the combination of mutation and demographic processes dominate in determining the relative fitness of secretors versus cheaters when measured over the full cycle of microbial life history. Key demographic factors include the local density of microbes at which secretion significantly alters the environment, the extent to which secretion enhances microbial growth and maximum local density, and the ways in which secretion alters colony survival and dispersal.
Divergence, demography and gene loss along the human lineage
Authors: Kim Hie Lim , Igawa Takeshi , Kawashima Ayaka , Satta Yoko , Takahata Naoyuki
Published: July 2010

Genomic DNA sequences are an irreplaceable source for reconstructing the vanished past of living organisms. Based on updated sequence data, this paper summarizes our studies on species divergence time, ancient population size and functional loss of genes in the primate lineage leading to modern humans (Homo sapiens sapiens). The inter- and intraspecific comparisons of DNA sequences suggest that the human lineage experienced a rather severe bottleneck in the Middle Pleistocene, throughout which period the subdivided African population played a predominant role in shaping the genetic architecture of modern humans. Also, published and newly identified human-specific pseudogenes (HSPs) are enumerated in order to infer their significance for human evolution. Of the 121 candidate genes obtained, authentic HSPs turn out to comprise only 25 olfactory receptor genes, four T cell receptor genes and nine other genes. The fixation of HSPs has been too rare over the past 6–7 Myr to account for species differences between humans and chimpanzees.
The genetic basis of evolutionary change in gene expression levels
Authors: Emerson J. J. , Li Wen-Hsiung
Published: July 2010

The regulation of gene expression is an important determinant of organismal phenotype and evolution. However, the widespread recognition of this fact occurred long after the synthesis of evolution and genetics. Here, we give a brief sketch of thoughts regarding gene regulation in the history of evolution and genetics. We then review the development of genome-wide studies of gene regulatory variation in the context of the location and mode of action of the causative genetic changes. In particular, we review mapping of the genetic basis of expression variation through expression quantitative trait locus studies and measuring thecis/transcomponent of expression variation in allele-specific expression studies. We conclude by proposing a systematic integration of ideas that combines global mapping studies,cis/transtests and modern population genetics methodologies, in order to directly estimate the forces acting on regulatory variation within and between species.
Adaptations to new environments in humans: the role of subtle allele frequency shifts
Authors: Hancock Angela M. , Alkorta-Aranburu Gorka , Witonsky David B. , Di Rienzo Anna
Published: July 2010

Humans show tremendous phenotypic diversity across geographically distributed populations, and much of this diversity undoubtedly results from genetic adaptations to different environmental pressures. The availability of genome-wide genetic variation data from densely sampled populations offers unprecedented opportunities for identifying the loci responsible for these adaptations and for elucidating the genetic architecture of human adaptive traits. Several approaches have been used to detect signals of selection in human populations, and these approaches differ in the assumptions they make about the underlying mode of selection. We contrast the results of approaches based on haplotype structure and differentiation of allele frequencies to those from a method for identifying single nucleotide polymorphisms strongly correlated with environmental variables. Although the first group of approaches tends to detect new beneficial alleles that were driven to high frequencies by selection, the environmental correlation approach has power to identify alleles that experienced small shifts in frequency owing to selection. We suggest that the first group of approaches tends to identify only variants with relatively strong phenotypic effects, whereas the environmental correlation methods can detect variants that make smaller contributions to an adaptive trait.
Convergence in pigmentation at multiple levels: mutations, genes and function
Authors: Manceau Marie , Domingues Vera S. , Linnen Catherine R. , Rosenblum Erica Bree , Hoekstra Hopi E.
Published: July 2010

Convergence—the independent evolution of the same trait by two or more taxa—has long been of interest to evolutionary biologists, but only recently has the molecular basis of phenotypic convergence been identified. Here, we highlight studies of rapid evolution of cryptic coloration in vertebrates to demonstrate that phenotypic convergence can occur at multiple levels: mutations, genes and gene function. We first show that different genes can be responsible for convergent phenotypes even among closely related populations, for example, in the pale beach mice inhabiting Florida's Gulf and Atlantic coasts. By contrast, the exact same mutation can create similar phenotypes in distantly related species such as mice and mammoths. Next, we show that different mutations in the same gene need not be functionally equivalent to produce similar phenotypes. For example, separate mutations produce divergent protein function but convergent pale coloration in two lizard species. Similarly, mutations that alter the expression of a gene in different ways can, nevertheless, result in similar phenotypes, as demonstrated by sister species of deer mice. Together these studies underscore the importance of identifying not only the genes, but also the precise mutations and their effects on protein function, that contribute to adaptation and highlight how convergence can occur at different genetic levels.
Evolution of quantitative traits in the wild: mind the ecology
Authors: Pemberton Josephine M.
Published: July 2010

Recent advances in the quantitative genetics of traits in wild animal populations have created new interest in whether natural selection, and genetic response to it, can be detected within long-term ecological studies. However, such studies have re-emphasized the fact that ecological heterogeneity can confound our ability to infer selection on genetic variation and detect a population's response to selection by conventional quantitative genetics approaches. Here, I highlight three manifestations of this issue: counter gradient variation, environmentally induced covariance between traits and the correlated effects of a fluctuating environment. These effects are symptomatic of the oversimplifications and strong assumptions of the breeder's equation when it is applied to natural populations. In addition, methods to assay genetic change in quantitative traits have overestimated the precision with which change can be measured. In the future, a more conservative approach to inferring quantitative genetic response to selection, or genomic approaches allowing the estimation of selection intensity and responses to selection at known quantitative trait loci, will provide a more precise view of evolution in ecological time.
The role of mTOR in memory CD8+ T‐cell differentiation
Authors: Araki Koichi , Youngblood Ben , Ahmed Rafi
Published: July 2010

Summary:  The mammalian target of rapamycin (mTOR) is an intracellular kinase that regulates cell growth and metabolism. Its specific inhibitor rapamycin is currently used in transplant recipients as an immunosuppressive drug to prevent allograft rejection. Studies have shown complex and diverse mechanisms for the immunosuppressive effects of rapamycin. The drug has been reported to inhibit T‐cell proliferation, induce anergy, modulate T‐cell trafficking, promote regulatory T cells, and also prevent maturation of dendritic cells as well as production of type I interferon. However, several other studies have paradoxically demonstrated immunostimulatory effects of rapamycin by improving antigen presentation and regulating cytokine production from macrophages and myeloid dendritic cells. Recently, it has been shown that rapamycin also exhibits immunostimulatory effects on memory CD8+ T‐cell differentiation. The drug improved both quantity and quality of memory CD8+ T cells induced by viral infection and vaccination, showing that mTOR is a major regulator of memory CD8+ T‐cell differentiation. These discoveries have implications for the development of novel vaccine regimens. Here, we review the role of mTOR in memory CD8+ T‐cell differentiation and compare the effect of rapamycin among CD8+ T cells, CD4+ T cells, and dendritic cells. Also, we discuss potential application of these findings in a clinical setting.
Translating the tears: parents' use of behavioural cues to detect pain in normally developing young children with everyday minor illnesses or injuries
Authors: Franck L. , Noble G. , Liossi C.
Published: July 2010

Objectives The objectives of this paper were to (i) identify the behavioural cues used by parents to detect young children's transient pain from minor illnesses or injuries (‘everyday pain’); and (ii) perform an initial psychometric evaluation of the Parents' Post‐operative Pain Measure (PPPM) in the context of children's everyday pain.

Method Cross‐sectional Internet survey.

Results One thousand seven hundred sixteen parents of children (1–6 years) completed the survey. The parents reported more behaviours when children had pain from minor illnesses than from minor injuries (9.6 ± 3.9 vs. 2.5 ± 2.3,P< 0.001). Principal component analysis of the PPPM revealed a two‐factor solution for illness‐related pain and a three‐factor solution for injury‐related pain. Behavioural cues varied with characteristics of children (age, gender and prior hospital experience) and parents (gender, age and parenting experience).

Conclusions The PPPM is a promising tool for parental assessment of children's pain in everyday situations. Further research is needed to determine its utility in facilitating communication between parents and healthcare professionals, and in improving the management of young children's pain.