bluuebunny/crossref_metadata_2025 huggingface dataset:
Methods and Model Development for Coupled RELAP5/PARCS Analysis of the Atucha‐II Nuclear Power Plant
Authors: Ward Andrew M. , Collins Benjamin S. , Madariaga Marcelo , Xu Yunlin , Downar Thomas J.
Published: February 2011

In order to analyze the steady state and transient behavior of CNA‐II, several tasks were required. Methods and models were developed in several areas. HELIOS lattice models were developed and benchmarked against WIMS/MCNP5 results generated by NA‐SA. Cross‐sections for the coupled RELAP5/PARCS calculation were extracted from HELIOS within the GenPMAXS framework. The validation of both HELIOS and PARCS was performed primarily by comparisons to WIMS/PUMA and MCNP for idealized models. Special methods were developed to model the control rods and boron injection systems of CNA‐II. The insertion of the rods is oblique, and a special routine was added to PARCS to treat this effect. CFD results combined with specialized mapping routines were used to model the boron injection system. In all cases there was good agreement in the results which provided confidence in the neutronics methods and modeling. A coupled code benchmark between U of M and U of Pisa is ongoing and results are still preliminary. Under a LOCA transient, the best estimate behavior of the core appears to be acceptable.
Continuous Glucose Monitoring for Evaluation of Glycemic Excursions after Gastric Bypass
Authors: Halperin Florencia , Patti Mary Elizabeth , Skow Megan , Bajwa Muhammad , Goldfine Allison B.
Published: February 2011

Background. Hyperinsulinemic hypoglycemia with neuroglycopenia is a rare complication of Roux-en-Y gastric bypass (RYGB). We hypothesized that continuous glucose monitoring (CGM) would be useful to characterize glycemic variability after RYGB.Methods. CGM and mixed meal tolerance testing (MMTT) were performed on sixteen post-RYGB subjects, ten with a history of neuroglycopenia on medical treatment and six asymptomatic controls.Results. 9 of 10 subjects with neuroglycopenia developed hypoglycemia defined by glucose <70 mg/dL on CGM, and 3 of 9 on MMTT. In asymptomatic subjects, 3 of 6 had asymptomatic hypoglycemia during CGM, and 3 of 5 on MMTT. Therefore, the sensitivity and specificity to detect clinically significant hypoglycemia was 90% and 50% for CGM and 33% and 40% for MMTT.Conclusions. Asymptomatic hypoglycemia after RYGB is more frequent than commonly recognized. For clinicians evaluating patients for postbypass neuroglycopenia, CGM may be a valuable diagnostic tool.
The Existence of Maximum and Minimum Solutions to General Variational Inequalities in the Hilbert Lattices
Authors: Li Jinlu , Yao Jen-Chih
Published: February 2011

We apply the variational characterization of the metric projection to prove some results about the solvability of general variational inequalities and the existence of maximum and minimum solutions to some general variational inequalities in the Hilbert lattices.
Postoperative Acute Exacerbation of IPF after Lung Resection for Primary Lung Cancer
Authors: Watanabe Atsushi , Kawaharada Nobuyoshi , Higami Tetsuya
Published: February 2011

Idiopathic pulmonary fibrosis (IPF) is characterized by slowly progressive respiratory dysfunction. Nevertheless, some IPF patients experience acute exacerbations generally characterized by suddenly worsening and fatal respiratory failure with new lung opacities and pathological lesions of diffuse alveolar damage. Acute exacerbation of idiopathic pulmonary fibrosis (AEIPF) is a fatal disorder defined by rapid deterioration of IPF. The condition sometimes occurs in patients who underwent lung resection for primary lung cancer in the acute and subacute postoperative phases. The exact etiology and pathogenesis remain unknown, but the condition is characterized by diffuse alveolar damage superimposed on a background of IPF that probably occurs as a result of a massive lung injury due to some unknown factors. This systematic review shows that the outcome, however, is poor, with postoperative mortality ranging from 33.3% to 100%. In this paper, the etiology, risk factors, pathogenesis, therapy, prognosis, and predictors of postoperative AEIPF are described.
High-Resolution Melting Analysis for Mutation Screening of RGSL1, RGS16, and RGS8 in Breast Cancer
Authors: Wiechec Emilia , Wiuf Carsten , Overgaard Jens , Hansen Lise Lotte
Published: February 2011

Background: Identification of specific mutation targets in cancer may lead to discovery of the genes modulating cancer susceptibility and/or prognosis. The RGSL1, RGS16, and RGS8 genes within the 1q25.3 region belong to the novel family of regulators of G protein signaling (RGS) genes, which increase the GTPase activity of the Gα subunit to attenuate signaling from the G protein–coupled receptor. We evaluated the use of high-resolution melting (HRM) to screen for mutations in the genes of interest and assess their clinical significance.

Methods: The HRM analysis was used to screen 32 coding exons of RGSL1, RGS16, and RGS8 in tumors from 200 breast cancer patients. All sequence variants detected by HRM resulted in abnormal shape of the melting curves. The identified mutations and known single nucleotide polymorphisms (SNP) were subsequently confirmed by sequencing, and distribution of the SNP genotypes was determined by SNaPshot analysis. A case–control analysis of genotype frequencies was carried out.

Results: We identified three tumor specific missense mutations in RGSL1 (ex6 c.664 G>A (Val222Ile), ex13 c.2262 C>G (Asp754Glu), and ex13 c.2316 C>T (Ser772Leu) in three different breast cancer patients. In addition, a total of seven known SNPs were identified in this study. Genotype distributions were not significantly different between breast cancer patients and controls.

Conclusions and Impact: Identification of novel mutations within RGSL1 provides a new insight into the pathophysiology of breast cancer. Moreover, the HRM analysis represents a reliable and highly sensitive method for mutation scanning of multiple exons. Cancer Epidemiol Biomarkers Prev; 20(2); 397–407. ©2010 AACR.
Nicotine Metabolite Ratio Predicts Smoking Topography and Carcinogen Biomarker Level
Authors: Strasser Andrew A. , Benowitz Neal L. , Pinto Angela G. , Tang Kathy Z. , Hecht Stephen S. , Carmella Steve G. , Tyndale Rachel F. , Lerman Caryn E.
Published: February 2011

Background: Variability in smoking behavior is partly attributable to heritable individual differences in nicotine clearance rates. This can be assessed as the ratio of the metabolites cotinine and 3′-hydroxycotinine (referred to as the nicotine metabolism ratio; NMR). We hypothesized that faster NMR would be associated with greater cigarette puff volume and higher levels of total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a carcinogen biomarker.

Methods: Current smokers (n = 109) smoked one of their preferred brand cigarettes through a smoking topography device and provided specimens for NMR and total NNAL assays.

Results: Faster nicotine metabolizers (third and fourth quartiles versus first quartile) based on the NMR exhibited significantly greater total puff volume and total NNAL; the total puff volume by daily cigarette consumption interaction was a significant predictor of total NNAL level.

Conclusion: A heritable biomarker of nicotine clearance predicts total cigarette puff volume and total NNAL.

Impact: If validated, the NMR could contribute to smoking risk assessment in epidemiologic studies and potentially in clinical practice. Cancer Epidemiol Biomarkers Prev; 20(2); 234–8. 2011 AACR.
Melanoma Incidence Rates among Whites in the U.S. Military
Authors: Zhou Jing , Enewold Lindsey , Zahm Shelia H. , Devesa Susan S. , Anderson William F. , Potter John F. , McGlynn Katherine A. , Zhu Kangmin
Published: February 2011

Background: The U.S. Military and general populations may differ in the exposure to sunlight and other risk factors for melanoma and therefore the incidence rates of melanoma may be different in these two populations. However, few studies have compared melanoma incidence rates and trends over time between the military and the general population.

Methods: Melanoma incidence rates from 1990 to 2004 among white active-duty military personnel and the general U.S. population were compared using data from the Department of Defense Automated Central Tumor Registry and the National Cancer Institute Surveillance, Epidemiology, and End Results program.

Results: Age-adjusted melanoma rates overall were significantly lower in the military than in the general population; the incidence rate ratio was 0.75 for men and 0.56 for women. Age-specific rates, however, were significantly lower among individuals younger than 45 years, but significantly higher among those 45 years or older (P < 0.05). Melanoma incidence increased from 1990–1994 to 2000–2004 in both populations, with the most rapid increase (40%) among younger men in the military. Melanoma incidence rates also varied by branch of military service; rates were highest in the air force.

Conclusion: These results suggest that melanoma incidence rate patterns differ between the military and the general population.

Impact: Further studies of risk factors for melanoma in the military are needed to explain these findings. Cancer Epidemiol Biomarkers Prev; 20(2); 318–23. ©2010 AACR.
A Case Study Addressing the Reliability of Polychlorinated Biphenyl Levels Measured at the Time of Breast Cancer Diagnosis in Representing Early-Life Exposure
Authors: Verner Marc-André , Bachelet Delphine , McDougall Robin , Charbonneau Michel , Guénel Pascal , Haddad Sami
Published: February 2011

Background: To date, breast cancer epidemiologic studies have relied on blood or tissue specimens sampled at the time of diagnosis or a few years prior to assess lifetime exposure to polychlorinated biphenyls (PCB). In this study, we evaluated whether such PCB measurements are indicative of early-life levels by reconstructing lifetime toxicokinetic profiles for women included in the CECILE case–control study, using a physiologically based pharmacokinetic (PBPK) model.

Methods: We simulated lifetime toxicokinetic profiles of PCB-153 for 2,134 French women by incorporating information on body weight history, height, pregnancies, and breast-feeding in the PBPK model. Oral dose was calculated by considering measured blood PCB-153 and the temporal trend of environmental contamination. Area under the concentration versus time curve (AUC) for each decade of life and maximum blood concentration (Cmax) were compiled and compared with measured levels, using Pearson partial correlation analyses adjusting for age at diagnosis.

Results: When considering all individuals, simulated AUCs correlated with measured PCBs, with coefficients ranging from 0.735 to 0.981. The weakest correlations were obtained with AUCs for the first decades of life. Stratified analyses suggested that breast-feeding reduces the reliability of late-life blood levels in representing lifetime exposure.

Conclusion: Results of this study suggest that PCB levels measured at the time of diagnosis do not fully represent early-life exposures.

Impact: PBPK-derived estimates of early-life levels circumvent the limitations of current approaches in assessing PCB lifetime exposure and may be used to address hypothesized windows of breast vulnerability (e.g., puberty) in this population. Cancer Epidemiol Biomarkers Prev; 20(2); 281–6. ©2010 AACR.
A Panel of Kallikrein Marker Predicts Prostate Cancer in a Large, Population-Based Cohort Followed for 15 Years without Screening
Authors: Vickers Andrew J. , Gupta Amit , Savage Caroline J. , Pettersson Kim , Dahlin Anders , Bjartell Anders , Manjer Jonas , Scardino Peter T. , Ulmert David , Lilja Hans
Published: February 2011

Background: Prostate-specific antigen (PSA) has modest specificity for prostate cancer. A panel of four kallikrein markers (total PSA, free PSA, intact PSA, and kallikrein-related peptidase 2) is a highly accurate predictor of biopsy outcome. The clinical significance of biopsy-detectable cancers in men classified as low-risk by this panel remains unclear.

Methods: The Malmö Diet and Cancer study is a population-based cohort of 11,063 Swedish men aged 45 to 73 providing a blood sample at baseline during 1991–1996. The Swedish Cancer Registry was used to identify 943 men diagnosed with prostate cancer by December 31, 2006. PSA testing was low. We assessed the predictive accuracy of our published statistical model to predict subsequent prostate cancer diagnosis in men with a total PSA level of 3.0 ng/mL or more at baseline.

Results: Compared with total PSA and age, the full kallikrein panel enhanced the predictive accuracy for clinically diagnosed prostate cancer (concordance index 0.65 vs. 0.75; P < 0.001). For every 1,000 men with a total PSA level of 3 ng/mL or more at baseline, the model would classify as high-risk 131 of 152 (86%) of the cancer cases diagnosed clinically within 5 years; 421 men would be classified as low-risk by the panel and recommended against biopsy. Of these, only 2 would be diagnosed with advanced prostate cancer (clinical T3–T4 or metastases) within 5 years.

Conclusions: Men with a PSA level of 3 ng/mL or more but defined as low-risk by the panel of four kallikrein markers are unlikely to develop incurable prostate cancer.

Impact: Use of the panel to determine referral to biopsy could substantially reduce the number of unnecessary prostate biopsies. Cancer Epidemiol Biomarkers Prev; 20(2); 255–61. ©2010 AACR.
Serum C-Reactive Protein and Risk of Pancreatic Cancer in Two Nested, Case–Control Studies
Authors: Douglas Jason B. , Silverman Debra T. , Weinstein Stephanie J. , Graubard Barry I. , Pollak Michael N. , Tao Yuzhen , Virtamo Jarmo , Albanes Demetrius , Stolzenberg-Solomon Rachael Z.
Published: February 2011

Background: Many epidemiologic studies have examined the association between C-reactive protein (CRP) and risk of cancer with inconsistent results.

Methods: We conducted two nested, case–control studies in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC) and Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) to test whether prediagnostic circulating CRP concentrations were associated with pancreatic adenocarcinoma. Between 1985 and 2004, 311 cases occurred in ATBC and between 1994 and 2006, 182 cases occurred in PLCO. Controls (n = 510 in ATBC, n = 374 in PLCO) were alive at the time the case was diagnosed and were matched by age, date of blood draw, sex, and race. We used conditional logistic regression adjusted for smoking to calculate OR and 95% CI for pancreatic cancer.

Results: CRP concentrations (ng/mL) tended to be inversely or not associated with pancreatic cancer risk in ATBC, PLCO, and combined analyses [per standardized quintile increase in CRP, continuous OR = 0.94 (95% CI, 0.89–0.99), OR = 0.99 (95% CI, 0.95–1.04), OR = 0.98 (95% CI, 0.95–1.01), respectively]. In combined analyses, we observed a significant interaction (Pinteraction = 0.02) such that inverse associations were suggestive in younger (OR = 0.95; 95% CI, 0.90–1.01), but not older, participants.

Conclusion: Our results do not support the hypothesis that higher CRP concentrations are associated with incident pancreatic cancer.

Impact: Our results highlight the importance of investigating more specific biomarkers for inflammation that may reflect the biological mechanisms underlying pancreatic cancer in prospective cohort studies. Cancer Epidemiol Biomarkers Prev; 20(2); 359–69. ©2010 AACR.
Vitamin Supplement Use During Breast Cancer Treatment and Survival: A Prospective Cohort Study
Authors: Nechuta Sarah , Lu Wei , Chen Zhi , Zheng Ying , Gu Kai , Cai Hui , Zheng Wei , Shu Xiao Ou
Published: February 2011

Background: Antioxidants may protect normal cells from the oxidative damage that occurs during radiotherapy and certain chemotherapy regimens; however, the same mechanism could protect tumor cells and potentially reduce effectiveness of cancer treatments. We evaluated the association of vitamin supplement use in the first 6 months after breast cancer diagnosis and during cancer treatment with total mortality and recurrence.

Methods: We conducted a population-based prospective cohort study of 4,877 women aged 20 to 75 years diagnosed with invasive breast cancer in Shanghai, China, between March 2002 and April 2006. Women were interviewed approximately 6 months after diagnosis and followed up by in-person interviews and record linkage with the vital statistics registry.

Results: During a mean follow-up of 4.1 years, 444 deaths and 532 recurrences occurred. Vitamin use shortly after breast cancer diagnosis was associated with reduced mortality and recurrence risk, adjusted for multiple lifestyle factors, sociodemographics, and known clinical prognostic factors. Women who used antioxidants (vitamin E, vitamin C, multivitamins) had 18% reduced mortality risk (HR = 0.82, 95% CI: 0.65–1.02) and 22% reduced recurrence risk (HR = 0.78, 95% CI: 0.63–0.95). The inverse association was found regardless of whether vitamin use was concurrent or nonconcurrent with chemotherapy, but was present only among patients who did not receive radiotherapy.

Conclusions: Vitamin supplement use in the first 6 months after breast cancer diagnosis may be associated with reduced risk of mortality and recurrence.

Impact: Our results do not support the current recommendation that breast cancer patients should avoid use of vitamin supplements. Cancer Epidemiol Biomarkers Prev; 20(2); 262–71. ©2010 AACR.
Association of Inflammatory Markers with Colorectal Cancer Incidence in the Atherosclerosis Risk in Communities Study
Authors: Prizment Anna E. , Anderson Kristin E. , Visvanathan Kala , Folsom Aaron R.
Published: February 2011

Background: Chronic inflammation has been implicated in the etiology of colorectal cancer (CRC), but epidemiologic findings on the association between circulating inflammatory markers and CRC risk are inconsistent. We hypothesized that increased concentrations of systemic inflammatory markers–white blood cell count (WBC), fibrinogen, von Willebrand factor (VWF), factor VIII (FVIII), and C-reactive protein (CRP)–and decreased albumin concentration would be associated with increased CRC risk in the Atherosclerosis Risk in Communities prospective cohort.

Methods: WBC, fibrinogen, VWF, FVIII, and albumin, measured in 1987–1989 in 13,414 men and women, were transformed to z-scores and summed up to construct a blood “inflammation z-score.” Albumin was included with a negative sign, because its concentration decreases with greater inflammation. A total of 308 incident CRC cases were identified through 2006 in initially cancer-free participants. CRP was measured in 1996–1998 in 9,836 cancer-free people who developed 166 CRCs through 2006. Proportional hazard models were used to estimate the HR and 95% CI of CRC in relation to each individual marker and the inflammation z-score.

Results: After multivariate adjustment, for the highest versus lowest quartile, there was a statistically significant positive association of CRC risk with fibrinogen: HR = 1.50 (95% CI, 1.05–2.15), P = 0.03; inflammation z-score: HR = 1.65 (95% CI, 1.15–2.35), P = 0.01; and CRP: HR = 1.97 (95% CI, 1.13–3.43, P = 0.02.

Conclusions: These findings indicate that greater levels of fibrinogen, CRP, and blood inflammation z-score are associated with increased CRC risk.

Impact: The study provides further evidence that precancer inflammation may contribute to CRC etiology. Cancer Epidemiol Biomarkers Prev; 20(2); 297–307. ©2011 AACR.
Improvements in Behaviour and Self-Esteem following Growth Hormone Treatment in Short Prepubertal Children
Authors: Chaplin John Eric , Kriström Berit , Jonsson Björn , Hägglöf Bruno , Tuvemo Torsten , Aronson A. Stefan , Dahlgren Jovanna , Albertsson-Wikland Kerstin
Published: February 2011

Background/Aims: To evaluate effects of growth hormone (GH) treatment on behaviour and psychosocial characteristics in short-stature children. Methods: 99 referred prepubertal non-familiar short-stature children (32 GH deficiency; 67 idiopathic short stature) aged 3–11 years, randomized to fixed or individual GH doses and their parents completed questionnaires (Child Behaviour Checklist, Birleson Depression Self-Report Scale, Abbreviated Parent-Teacher Questionnaire, I Think I Am, Well-Being Visual-Analogue Scales for Short-Stature Children) at baseline (BL) and after 3, 12, and 24 months. Results: At BL, children showed higher levels of internalizing behaviour (p < 0.001), lower levels of externalizing behaviour (p < 0.006) and self-esteem (p < 0.001) compared to reference values. During GH treatment, behavioural measures (p < 0.001) and depression (p < 0.01) changed towards the mean of the population within the first 3 months and remained improved to 24 months. Self-esteem improved at all time points (p < 0.001), and in all subgroups, as did well-being dimensions stability and mood (p < 0.05). Multiple regression analysis showed that greater improvements were related to lower BL value, height gain, higher maximal GH value, being older, and being male. Conclusion: On GH treatment, prepubertal short children significantly improved on behavioural, depression, and psychosocial evaluations over a 2-year period of GH treatment. Most change occurred within the first 3 months, which highlights this short period as important not only for growth and metabolic changes but also for behaviour and psychosocial improvements following GH treatment.
Genome-Wide Linkage Screen for Systolic Blood Pressure in the Veterans Administration Genetic Epidemiology Study (VAGES) of Mexican-Americans and Confirmation of a Major Susceptibility Locus on Chromosome 6q14.1
Authors: Puppala Sobha , Coletta Dawn K. , Schneider Jennifer , Hu Shirley L. , Farook Vidya S. , Dyer Thomas D. , Arya Rector , Blangero John , Duggirala Ravindranath , DeFronzo Ralph A. , Jenkinson Christopher P.
Published: February 2011

Objective: Hypertension or high blood pressure is a strong correlate of diseases such as obesity and type 2 diabetes. We conducted a genome-wide linkage screen to identify susceptibility genes influencing systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Mexican-Americans from the Veterans Administration Genetic Epidemiology Study (VAGES). Methods: Using data from 1,089 individuals distributed across 266 families, we performed a multipoint linkage analysis to localize susceptibility loci for SBP and DBP by applying two models. In model 1, we added a sensible constant to the observed BP values in treated subjects [Tobin et al.; Stat Med 2005;24:2911–2935] to account for antihypertensive use (i.e. 15 and 10 mm Hg to SBP and DBP values, respectively). In model 2, we fixed values of 140 mm Hg for SBP and 90 mm Hg for DBP, if the treated values were less than the standard referenced treatment thresholds of 140/ 90 mm Hg for hypertensive status. However, if the observed treated BP values were found to be above these standard treatment thresholds, the actual observed treated BP values were retained in order not to reduce them by substitution of the treatment threshold values. Results: The multipoint linkage analysis revealed strong linkage signals for SBP compared with DBP. The strongest evidence for linkage of SBP (model 1, LOD = 5.0; model 2, LOD = 3.6) was found on chromosome 6q14.1 near the marker D6S1031 (89 cM) in both models. In addition, some evidence for SBP linkage occurred on chromosomes 1q, 4p, and 16p. Most importantly, our major SBP linkage finding on chromosome 6q near marker D6S1031 was independently confirmed in a Caucasian population (LOD = 3.3). In summary, our study found evidence for a major locus on chromosome 6q influencing SBP levels in Mexican-Americans.
Intravenous Pamidronate Treatment Improves Growth in Prepubertal Osteogenesis Imperfecta Patients
Authors: Heino Terhi J. , Åström Eva , Laurencikas Evaldas , Sävendahl Lars , Söderhäll Stefan
Published: February 2011

Background/Aims: Pamidronate is widely used to treat pediatric patients with osteogenesis imperfecta (OI). We aimed at delineating the effects of monthly pamidronate therapy on the growth of different body segments in prepubertal OI patients. Methods: The study included 14 prepubertal patients (12 boys, 2 girls) with mild forms of OI (type I and IV). The mean age at treatment start was 7:8 years:months (3:7–11:0). Pamidronate was given as monthly intravenous infusions. The patients were measured 1 year before, at treatment start and 1 and 2 years after treatment start. Results: Height standard deviation score (SDS) and sitting height SDS significantly increased (p < 0.05) during the first year of treatment when compared to the pre-treatment year. No further improvement was detected during the second year of treatment. However, when plotted on disease-specific growth charts (untreated patients with the same OI types), height gain was significant during the first (p < 0.001) and second (p < 0.05) years of treatment. All patients increased their bone mineral density throughout the follow-up. Conclusion: Monthly pamidronate improves the growth of prepubertal patients with mild OI, where the most prominent growth stimulation is seen in the upper body segment.
Traveling Bumps and Their Collisions in a Two-Dimensional Neural Field
Authors: Lu Yao , Sato Yuzuru , Amari Shun-ichi
Published: February 2011

A neural field is a continuous version of a neural network model accounting for dynamical pattern forming from populational firing activities in neural tissues. These patterns include standing bumps, moving bumps, traveling waves, target waves, breathers, and spiral waves, many of them observed in various brain areas. They can be categorized into two types: a wave-like activity spreading over the field and a particle-like localized activity. We show through numerical experiments that localized traveling excitation patterns (traveling bumps), which behave like particles, exist in a two-dimensional neural field with excitation and inhibition mechanisms. The traveling bumps do not require any geometric restriction (boundary) to prevent them from propagating away, a fact that might shed light on how neurons in the brain are functionally organized. Collisions of traveling bumps exhibit rich phenomena; they might reveal the manner of information processing in the cortex and be useful in various applications. The trajectories of traveling bumps can be controlled by external inputs.
On the Performance of Voltage Stepping for the Simulation of Adaptive, Nonlinear Integrate-and-Fire Neuronal Networks
Authors: Kaabi Mohamed Ghaith , Tonnelier Arnaud , Martinez Dominique
Published: February 2011

In traditional event-driven strategies, spike timings are analytically given or calculated with arbitrary precision (up to machine precision). Exact computation is possible only for simplified neuron models, mainly the leaky integrate-and-fire model. In a recent paper, Zheng, Tonnelier, and Martinez ( 2009 ) introduced an approximate event-driven strategy, named voltage stepping, that allows the generic simulation of nonlinear spiking neurons. Promising results were achieved in the simulation of single quadratic integrate-and-fire neurons. Here, we assess the performance of voltage stepping in network simulations by considering more complex neurons (quadratic integrate-and-fire neurons with adaptation) coupled with multiple synapses. To handle the discrete nature of synaptic interactions, we recast voltage stepping in a general framework, the discrete event system specification. The efficiency of the method is assessed through simulations and comparisons with a modified time-stepping scheme of the Runge-Kutta type. We demonstrated numerically that the original order of voltage stepping is preserved when simulating connected spiking neurons, independent of the network activity and connectivity.
The Dynamics of Integrate-and-Fire: Mean Versus Variance Modulations and Dependence on Baseline Parameters
Authors: Pressley Joanna , Troyer Todd W.
Published: February 2011

The leaky integrate-and-fire (LIF) is the simplest neuron model that captures the essential properties of neuronal signaling. Yet common intuitions are inadequate to explain basic properties of LIF responses to sinusoidal modulations of the input. Here we examine responses to low - and moderate-frequency modulations of both the mean and variance of the input current and quantify how these responses depend on baseline parameters. Across parameters, responses to modulations in the mean current are low pass, approaching zero in the limit of high frequencies. For very low baseline firing rates, the response cutoff frequency matches that expected from membrane integration. However, the cutoff shows a rapid, supralinear increase with firing rate, with a steeper increase in the case of lower noise. For modulations of the input variance, the gain at high frequency remains finite. Here, we show that the low-frequency responses depend strongly on baseline parameters and derive an analytic condition specifying the parameters at which responses switch from being dominated by low versus high frequencies. Additionally, we show that the resonant responses for variance modulations have properties not expected for common oscillatory resonances: they peak at frequencies higher than the baseline firing rate and persist when oscillatory spiking is disrupted by high noise. Finally, the responses to mean and variance modulations are shown to have a complementary dependence on baseline parameters at higher frequencies, resulting in responses to modulations of Poisson input rates that are independent of baseline input statistics.
Time-Free Spiking Neural P Systems
Authors: Pan Linqiang , Zeng Xiangxiang , Zhang Xingyi
Published: February 2011

Different biological processes take different times to be completed, which can also be influenced by many environmental factors. In this work, a realistic definition of nonsynchronized spiking neural P systems (SN P systems, for short) is considered: during the work of an SN P system, the execution times of spiking rules cannot be known exactly (i.e., they are arbitrary). In order to establish robust systems against the environmental factors, a special class of SN P systems, called time-free SN P systems, is introduced, which always produce the same computation result independent of the execution times of the rules. The universality of time-free SN P systems is investigated. It is proved that these P systems with extended rules (several spikes can be produced by a rule) are equivalent to register machines. However, if the number of spikes present in the system is bounded, then the power of time-free SN P systems falls, and in this case, a characterization of semilinear sets of natural numbers is obtained.
Mechanisms That Modulate the Transfer of Spiking Correlations
Authors: Rosenbaum Robert , Josić Krešimir
Published: February 2011

Correlations between neuronal spike trains affect network dynamics and population coding. Overlapping afferent populations and correlations between presynaptic spike trains introduce correlations between the inputs to downstream cells. To understand network activity and population coding, it is therefore important to understand how these input correlations are transferred to output correlations.Recent studies have addressed this question in the limit of many inputs with infinitesimal postsynaptic response amplitudes, where the total input can be approximated by gaussian noise. In contrast, we address the problem of correlation transfer by representing input spike trains as point processes, with each input spike eliciting a finite postsynaptic response. This approach allows us to naturally model synaptic noise and recurrent coupling and to treat excitatory and inhibitory inputs separately.We derive several new results that provide intuitive insights into the fundamental mechanisms that modulate the transfer of spiking correlations.
Are solitary progressive-provisioning wasps optimal foragers? A study with the digger wasp Bembix merceti (Hymenoptera: Crabronidae)
Authors: Ballesteros  , Baños-Picón  , Gayubo S.F. , Tormos  , Alonso  , Asís
Published: February 2011

Bembix merceti, a central-place forager that captures dipterans to feed its larvae, could be considered a suboptimal forager. The females tend to optimize their provisioning flights, capturing prey in proportions different from those present in the surrounding environment. These wasps make a positive selection of families of flies with greater mean weights even though they are less abundant and, within the families whose weight is not too great, capture individuals whose weight is larger than the mean. Selection is based on prey size and not on the type (family) to which the prey belongs. A significant correlation between the weight of each female and the weight of the largest prey captured by the wasp was found, suggesting that the females capture prey in consonance with their lift capacity. Nevertheless, captures were not optimized maximally; the females maintained a margin with respect to the maximum prey weights that they could transport efficiently. This margin could be related to the low availability of large prey in the environment; to the type of progressive provisioning shown by the females of this species; and to other factors, such as the good manoeuvrability of their prey and the pressure from their natural enemies and congeners.
Altitudinal differentiation of reproductive tactic plasticity despite the close proximity of two Aquarius remigis populations
Authors: Wilcox Stimson , Dlugos Michael
Published: February 2011

In the water strider (Aquarius remigis), direct and delayed reproductive tactics are largely canalized in southern and northern areas of North America, respectively. A transition zone occurs in upstate New York, defined as the area where lowland striders plastically express either tactic based on photoperiod and food abundance cues. We tested whether these cues similarly influence tactics among higher altitude transition zone populations. We compared the proportion of direct reproducers from a high altitude stream (HAS) and a low altitude stream (LAS) reared under low and high food abundance, as well as a normal and late-solstice photoperiod. With sexes combined, higher proportions of direct reproducers were found among LAS striders, and among striders reared in the late solstice photoperiod and high food abundance treatments. Among males, a food abundance × stream interaction was significant, suggesting greater canalization of reproductive tactics among HAS males. Among females, photoperiod was a significant factor, but did not interact with stream of origin. Field measurements showed that water surface temperatures and food abundance were lower in HAS compared to LAS. These conditions, as well as shorter season lengths, likely select against direct reproduction among HAS striders, possibly resulting in the observed canalization of reproductive tactics.
The Strange Case of Ben Kadosh: A Luciferian Pamphlet from 1906 and its Current Renaissance
Authors: Faxneld Per
Published: February 2011

In diesem Aufsatz wird ein früher und ziemlich unbekannter Satanist namens Ben Kadosh behandelt (Carl William Hansen 1872–1936), der in Dänemark am Anfang des 20en Jahrhunderts tätig war. Kadosh hat in der Gründung mehreren Freimauerlogen teilgenommen und stand mit einer Reihe von wohlbekannten esoterischen und literarischen Persönlischkeiten in Verbindung. Als sein System eine eklektische Mischung darstellte, wo der griechische Gott Pan beispielsweise mit Gnostizismus, Freimauermystizismus und Lobpreisungen von Luzifer verbunden wird, können verschiedene möglische Influenzen auf seine Lehre angeführt werden. Es ist ganz unwahrscheinlich, daß Kadosch in seiner Zeit mehrere Anhänger gewonnen hat. Heutzutage sind aber seine Idéen von einer Gruppe rehabilitiert worden, die hauptsätzlich in Dänemark und Schweden aktiv ist. Wichtiger für die Anhänger dieser Gruppe erscheint die Verwendung von Kadosh als ein Werkzeug um ihre eigene Wirksamkeit Legitimität und historische Würzeln zu geben, als für die eigentliche Fortsetzung seiner Gedanken zu sorgen.
'Hell in a Very Small Place' Cold War and Decolonisation in the Assault on the Vietnamese Body at Dien Bien Phu
Authors: Goscha Christopher
Published: February 2011

This essay examines how Vietnamese combatants of the communist-led Democratic Republic of Vietnam may have experienced battle during the Indochina War's most intensive phase beginning in 1950 and culminating in the Vietnamese victory over the French at Dien Bien Phu in 1954. It seeks to provide what is almost always missing in military histories of Dien Bien Phu—the unprecedented assault on the Vietnamese body. It uses the Vietnamese experience to think about what might be some of the similarities and differences between the Western experience of war and those occurring in the non-Western world, especially at this deadly southern intersection between decolonization and the Cold War. Vietnamese bodies were particularly vulnerable to the technological destruction of modern war as decolonization and the Cold War combined in an explosive and uneven mix from 1950.
Autopsy of a Massacre On a Political Purge in the Early Days of the Indochina War (Nam Bo 1947)
Authors: Guillemot François
Published: February 2011

This paper examines the history of an unknown “mass murder” perpetrated in 1947 in Southern Vietnam by the Viet Minh forces. It was organized in the outskirts of Saigon, mainly against Cao Dai and Hoa Hao religious forces that were portrayed as “reactionary” during their political revolutionary trials. Before presenting and analyzing the data of nearly 900 victims, the paper briefly presents the social, political and military conquest and context of French Cochinchina, as well as explains the political and military ambitions of the Viet Minh forces after the advent of the Democratic Republic of Vietnam in Hanoi on September 2, 1945. The focal point of this article is the review of the data related to the massacre and its uses, i.e.what they can reveal about the course of the massacre, its actors and victims. Finally, the paper's last section assesses the official historiography of the massacre, which has been recognized by the current regime in a 'soft' mea culpa. In conclusion, this article discusses the issue of violence in Southern Vietnam and its consequences for the Socialist Republic of Vietnam in a more long term perspective.
Life under Bombing in Southeastern Laos (1964–1973) Through the Accounts of Survivors in Sepon
Authors: Pholsena Vatthana
Published: February 2011

This article draws on fieldwork carried out between 2004 and 2010 in the rural district of Sepon, located in the east of Savannakhet Province in southern Laos. The area was heavily bombed by U.S. forces between 1964 and 1973 in an attempt to stop North Vietnamese supplies flowing into South Vietnam from the North via the transportation network widely known as the Ho Chi Minh Trail. The district of Sepon constituted a strategic centre and logistics base area for the North Vietnamese Army, and was one of the most important nodes on the Trail. This paper represents an attempt to reconstruct life under aerial bombardment through the recollections of some survivors. The majority of recollections concerned aspects of day-to-day survival, including the most routine tasks of daily life that, under bombardment, became major challenges. However, some survivors dwelt on more profound issues, notably their remembrance of the period as a 'Dark Age' characterized by a loss of their humanity. Silences—untold or absent memories—are also present in the villagers' accounts, which we view not as an obstacle to the telling of their stories, but as an integral constituent of their recollections.
A Neighbourhood under Storm Zhabei and Shanghai Wars
Authors: Henriot Christian
Published: February 2011

War was a major aspect of Shanghai history in the first half of the twentieth century. Yet, because of the particular political and territorial divisions that segmented the city, war struck only in Chinese-administered areas. In this paper, I examine the fate of the Zhabei district, a booming industrious area that came under fire on three successive occasions. Whereas Zhabei could be construed as a success story—a rag-to-riches, swamp-to-urbanity trajectory—the three instances of military conflict had an increasingly devastating impact, from shaking, to stifling, to finally erase Zhabei from the urban landscape. This area of Shanghai experienced the first large-scale modern warfare in an urban setting. The 1927 skirmish established the pattern in which the civilian population came to be exposed to extreme forms of violence, was turned overnight into a refugee population, and lost all its goods and properties to bombing and fires.
Troubled Neighbours: Japan's Negative Economic Diplomacy Towards North Korea
Authors: Okano-Heijmans Maaike
Published: February 2011

The importance of economic issues, in a comprehensive multilateral and bilateral context, has been receiving increased attention in writings about the Korean Peninsula lately. This article adds to this debate by analysing Japan's relations with North Korea from an economic diplomacy perspective. The concept of 'negative economic diplomacy' is introduced to understand actions of the Japanese government, which had tried economic engagement in various ways until the early 1990s, but hardened its stance thereafter. Tokyo seems to have come to the conclusion that North Korean rulers are more willing to preserve the status quo than some wish to believe and, consequently, started to use the North Korean threat to justify Japan's controversial military enhancement in a context of uncertainty about the United States' commitment and an increasingly stronger China. is strategy was practised through a negative approach to economic diplomacy of withholding economic benefits—in policy fields ranging from the abductees and normalisation of diplomatic relations, to trade relations, sanctions and the six-way process. Japan's policy was most outspoken from late 2002 until at least mid-2007.
Book Production and Its Regulation during the German Occupation of the Netherlands
Authors: Renders Hans
Published: February 2011

During the occupation of the Netherlands in the Second World War, the country’s book industry was subjected to control by a number of official bodies, both German and Dutch, in addition to which the German Sicherheitsdienst (SD) was also prone to interfering with the production and distribution of printed matter. In contrast to the sanctions imposed on the journalistic press, book production was censored preventively by a specially established reading panel called the Lectoraat. In reality, however, at least as effective an instrument of censorship was the government department responsible for allocating paper supplies. The article presents an overview of the legislation and regulations to which booksellers, writers and publishers had to adhere in the successive phases of the occupation.
‘We Mature into a Resilient People’ Publishing House De Amsterdamsche Keurkamer
Authors: Groeneveld Gerard
Published: February 2011

De Amsterdamsche Keurkamer, founded in 1932, was the first National Socialist publishing house in the Netherlands. Under the management of author and poet George Kettmann the firm grew to become one of the major cultural mainstays of National Socialism in Holland. Kettmann earned himself some sort of reputation in the late thirties when he brought out a Dutch translation of Hitler’s Mein Kampf. In the years of the occupation his company succeeded in defining the position and character of the ‘official’ literature ‐ ‘official’ meaning in line with National Socialist ideology.
The K number
Authors: Kruis René , van der Stroom Gerrold
Published: February 2011

Some books printed in occupied Holland during the Second World War carry a so-called K number. This was long supposed to signify approval by the Kultuurkamer, a ‘wrong’ (i.e. a pro-German or, as in this case, puppet) body that was set up in November 1941 by the country’s German governor or Reichskommissar. It has now become clear that this is incorrect: the K number was in fact introduced in July 1941 as a bureaucratic means of monitoring and controlling the supply and rationing of all printing paper by the Dutch Department of Economic Affairs, and was a consequence of pre-war Dutch rationing legislation dating from 1939.
Sovereignty beyond the West: The End of Classical International Law
Authors: Lorca Arnulf Becker
Published: February 2011

The historical processes through which international law became, conceptually, a universal legal order and, geographically, an order with a global scope of validity, are long and complex. These transformations, which began to appear during the second half of the nineteenth century, did not end until post-War-World-II decolonization. This article examines one particular aspect of these transformations: once non-Western states were admitted and begun to participate in the international community, did the rules of international law governing the interaction between Western and non-Western States change? What did it mean for semi-peripheral states to acquire sovereignty? The article argues that during the first decades of the twentieth century, semi-peripheral lawyers realized that sovereignty, so longed-for during the nineteenth century, conferred, under classical international law, much less autonomy and equality than they had anticipated. Moreover, at the turn of the century, the specific challenges faced by semi-peripheral states in their interaction with Western powers shifted, so that classical international law exhausted its power and stopped being useful. The article thus offers, from the perspective of the semi-periphery, an explanation of the shift from classical to modern international law.
Universalism and Equal Sovereignty as Contested Myths of International Law in the Sino-Western Encounter
Authors: Chen Li
Published: February 2011

Contrary to the relevant traditional historiography, this article argues that early modern Sino-Western conflicts are to a great extent attributable to the sustained contestation between China and the Western empires (particularly Britain) over their competing claims to sovereignty in China. The article shows that the Western empires' demand for extraterritoriality and natural rights to freely trade, travel, and proselytize in China originated in their assumption of universal sovereignty in the non-Christian world. The early Sino-Western encounter illustrates how the discourses of sovereign equality and universal justice, as two origin myths of modern international law and diplomacy, were constructed, deployed, challenged, and adapted in the course of Western expansion in the age of empire.
The Wilsonian Challenge to International Law
Authors: Smith Leonard
Published: February 2011

After the Great War, Woodrow Wilson challenged the foundations of international law based on fully sovereign states. “Wilsonianism” as elaborated in the Fourteen Points, and in other speeches, rested on a logic that made a universalized liberal individual the locus of sovereignty in the new world order. The truly radical implications of Wilsonianism had no sterner critic than Robert Lansing, Wilson's secretary of state and one of the founders of the American Journal of International Law. Lansing held tenaciously to a positivist paradigm of international law as it had evolved by the early twentieth century. This article reconsiders the conflict between Wilson and Lansing not so much as a duel between individuals as a duel between conflicting conceptions of sovereignty and the purpose of international law in the new world order.