bluuebunny/crossref_metadata_2025 huggingface dataset:
Issues on Viscoplastic Characterization of Lead-Free Solder for Drop Test Simulations
Authors: Bonnaud Etienne L.
Published: December 2011

Reliable drop test simulations of electronic packages require reliable material characterization of solder joints. Mechanical properties of lead-free solder were here experimentally investigated for both monotonic and cyclic loading at different strain rates. With regards to the observed complex material behavior, the nonlinear mixed hardening Armstrong and Frederick model combined with the Perzyna viscoplastic law was chosen to fit the experimental data. This model was subsequently implemented into a commercial finite element code and used to simulate drop tests. Actual drop test experiments were conducted in parallel and experimental results were compared to simulations. Prediction discrepancies were analyzed and explanations suggested.
EFFECTS OF INTER-PARTICLE INTERACTIONS AND HYDRODYNAMICS ON THE BROWNIAN COAGULATION RATE OF POLYDISPERSE NANOPARTICLES
Authors: LIN JIAN-ZHONG , WANG YU-MING
Published: December 2011

The Brownian coagulation rate of polydisperse nanoparticles by considering the effects of inter-particle interactions and hydrodynamics is studied in the gas-slip regime. The collision efficiency before and after particle contact is calculated by considering the van der Waals force, electrical repulsion, electrostatic force and elastic deformation force, respectively. It is found that the total collision efficiency decreases with the increase of both particle diameter and particle size ratio. Based on the total collision efficiency, the coagulation rate of polydisperse nanoparticles with considering the effects of inter-particle interactions and hydrodynamics is calculated. The results show that the coagulation rate with considering such effects is closer to the experimental data and much smaller than that without considering the effects. The inter-particle interactions and hydrodynamics make particles more difficult to coagulate and cause the coagulation rate to become weaker when the Knudsen number increases. The particles with high polydispersity coagulate more easily.
TEMPERATURE-DEPENDENCE OF STRONG-COUPLED BOUND POLARON IN A TRIANGULAR POTENTIAL QUANTUM DOT
Authors: LI ZHI-XIN
Published: December 2011

We study the temperature effect of bound polaron, which is strongly coupled to LO-phonon by using a variational method of the Pekar type in a triangular potential quantum dot (QD). The ground state energy was expressed as functions of the confinement length of QD, the Coulomb bound potential, the polar angle and the temperature. It is found that at low temperature, the influence of Coulomb bound potential and the confinement length of QD to the ground state energy of bound polaron play a leading role. At high temperature, the influence of temperature to the ground state energy of bound polaron is dominant.
PHASE TRANSITION IN THE HALF-FILLED IONIC HUBBARD MODEL: MEAN-FIELD SLAVE BOSON STUDY
Authors: LE DUC-ANH , HOANG ANH-TUAN
Published: December 2011

We study electronic phase transitions in the half-filled ionic Hubbard model with an on-site Coulomb repulsion U and an ionic energy Δ by using the Kotliar–Ruckenstein slave-boson theory. Assuming a paramagnetic solution, we show that for any non-zero values of Δ, with increasing U the system undergoes a transition from band-insulator to Mott-insulator. Our results have implied the absence of a metallic phase between the band and the Mott insulator phases.
THE DEPENDENCE OF ALUMINA NANOWIRE FORMATION FROM POROUS ANODIC ALUMINA MEMBRANES ON THE ETCHING SOLUTION
Authors: HAN JIN KYU , KWAK JIN HO , CHOI YONG CHAN , BU SANG DON
Published: December 2011

We describe variations in the structure and formation mechanism of alumina nanowires (ANWs) formed from porous anodic alumina (PAA) membranes, depending on the composition of the etching solution. Two types of ANWs were synthesized by etching PAA membranes in etching solutions containing H 3 PO 4 or NaOH . Not only did the ANW formation mechanism vary, but also the morphological properties and the surface chemical composition of the ANWs varied with the etching solution used. These results suggest that the ANW surfaces may be optimized by the appropriate selection of etching solution. The optimization of ANWs may potentially advance, for example, water purification technological developments because ANWs have, in recent studies, provided more effective filtration performances than nanoporous alumina membrane filters.
FABRICATION OF A POLYMER-ON-SILICA HYBRID THERMO-OPTIC SWITCH WITH FAST RESPONSE TIME AND LOW POWER CONSUMPTION
Authors: YAN YUN-FEI , ZHAO PENG-CHENG , ZHENG CHUAN-TAO , SUN XIAO-QIANG , LI DE-HUI , WANG FEI , ZHANG DA-MING
Published: December 2011

A polymer-on-silica Mach–Zehnder interferometer (MZI) TO switch is experimentally demonstrated using core polymer material with large thermo-optic (TO) coefficient. In the hybrid structure, the negative photoresist SU-8 and silica are used as core and lower cladding, respectively. Wet-etching technique is adopted to optimize fabrication process and diminish sidewall roughness and scattering loss. Compared to our two previously reported works, this switch exhibits better performance with lower power consumption of less than 4.8 mW, higher extinction ratio of 22.5 dB, shorter rise time of 141 μs and fall time of 87 μs, due to the larger thermal conductivity of silica relative to polymer in the proposed hybrid configuration.
Validation of the Danish Version of Functional Assessment of Multiple Sclerosis: A Quality of Life Instrument
Authors: Sørensen Jan , Bay Jette , Damsgaard Torben , Heeley Elsebeth , Rostgaard Ida , Løvendahl Brita , Boesen Finn
Published: December 2011

The functional assessment of multiple sclerosis (FAMS) is a disease-specific instrument that describes functional status of individuals with multiple sclerosis. The instrument was originally developed in the US and has been adapted to different languages including Danish. This study is a validation of the Danish version of FAMS in a sample of individuals referred to a four-week rehabilitation program at either of the two Multiple Sclerosis Rehabilitation centers in Denmark. FAMS data were obtained through self-completed questionnaires from 190 individuals who attended the rehabilitation centers after referral by their general practitioner or specialist neurologist. The validation of the FAMS included assessment of data quality, scale assumptions, acceptability, construct validity, and reliability. Responsiveness was assessed by comparing individual FAMS scores at admission with the discharge score for groups of respondents who reported no change, improvement, or deterioration in their ability to cope with their illness. The Danish version of FAMS appears to be an acceptable, valid, and reliable measure of current health and functional status of individuals with multiple sclerosis.
A Unique Case of Autoimmune Retinopathy Associated with Anti-Alpha-Enolase Antibodies
Authors: Kurz Paul A. , Reem Rachel E. , Kurz Daryl E. , Weleber Richard G.
Published: December 2011

Background. We report a case of autoimmune retinopathy associated with anti-alpha-enolase antibodies with unique manifestations.Methods. A case report.Results. A 30-year-old male experienced recurrent, primarily peripheral visual field disturbances and minimal photopsia, with interval symptom resolution. Fundus changes subsequently developed in areas corresponding to the previous visual field symptoms. Electroretinogram showed bilaterally symmetric abnormalities of light-adapted responses and suggested loss of photoreceptor function. Only anti-alpha-enolase antibodies were detected on Western blot. Our patient noted cutaneous symptoms at the time of both episodes of visual symptoms, but not in the interim. Biomicroscopy revealed subtle small reddish spots in areas of the peripheral retina corresponding to the areas of the patient’s visual field where he noted symptoms. To our knowledge these reddish spots have not been reported in autoimmune retinopathy and may clinically supportin vitroandin vivoevidence that anti-alpha-enolase antibodies may target photoreceptors.Conclusions. Our patient demonstrates some unique features adding to the known characteristics of autoimmune retinopathy associated with anti-alpha-enolase antibodies. As more cases are reported, further understanding of the features and pathophysiology of this rare condition will hopefully be elucidated.
Chromosome Visualization Tool: A Whole Genome Viewer
Authors: Cannon Ethalinda K. S. , Cannon Steven B.
Published: December 2011

CViT (chromosome visualization tool) is a Perl utility for quickly generating images of features on a whole genome at once. It reads GFF3-formated data representing chromosomes (linkage groups or pseudomolecules) and sets of features on those chromosomes. It can display features on any chromosomal unit system, including genetic (centimorgan), cytological (centiMcClintock), and DNA unit (base-pair) coordinates. CViT has been used to track sequencing progress (status of genome sequencing, location and number of gaps), to visualize BLAST hits on a whole genome view, to associate maps with one another, to locate regions of repeat densities to display syntenic regions, and to visualize centromeres and knobs on chromosomes.
Late Renal Allograft Rupture Associated with Cessation of Immunosuppression following Graft Failure
Authors: Askandarani Sumayah , Aloudah Noura , Al Enazi Hanan , Alsaad Khaled O. , Altamimi Abdulrahman
Published: December 2011

A 29-year-old man developed chronic allograft nephropathy 63 months after renal transplantation. He became symptomatic with advanced chronic graft failure; his immunosuppressive medications were reduced and he was commenced on haemodialysis. Two months following the withdrawal of immunosuppression, he presented with abdominal pain, haematuria, and a marked drop in haemoglobin. The patient was taken to the operating room, where the renal allograft was found to be ruptured, and graft nephrectomy was subsequently performed. Histological examination of the graft specimen showed severe haemorrhagic acute vascular cellular rejection in a background of marked chronic allograft vasculopathy. Immunostaining for C4d showed diffuse, strong, linear circumferential staining of the peritubular capillaries, indicating a concurrent antibody-mediated rejection. We report herein an unusual case of spontaneous renal allograft rupture that occurred long time after transplantation due to severe acute rejection following cessation of immunosuppressive medications for advanced chronic allograft failure. To the best of our knowledge, the time interval between transplantation and the rupture of this allograft is the longest of those reported in the literature.
Scientific Rationale for the Use of Alpha-Adrenergic Agonists and Glucocorticoids in the Therapy of Pediatric Stridor
Authors: Nino Gustavo , Baloglu Orkun , Gutierrez Maria J. , Schwartz Michael
Published: December 2011

Purpose. The most common pharmacological therapies used in the treatment of stridor in children are glucocorticosteroids (GC) and alpha-adrenergic (αAR) agonists. Despite the long-standing reported efficacy of these medications, there is a paucity of data relating to their actual mechanisms of action in the upper airway.Summary. There is compelling scientific evidence supporting the use of αAR-agonists and GCs in pediatric stridor. αAR signaling and GCs regulate the vasomotor tone in the upper airway mucosa. The latter translates into better airflow dynamics, as delineated by human and nonhuman upper airway physiological models. In turn, clinical trials have demonstrated that GCs and the nonselective αAR agonist, epinephrine, improve respiratory distress scores and reduce the need for further medical care in children with stridor. Future research is needed to investigate the role of selective αAR agonists and the potential synergism of GCs and αAR-signaling in the treatment of upper airway obstruction and stridor.
Verbal Episodic Memory and Endogenous Estradiol: An Association in Patients with Mild Cognitive Impairment and Alzheimer's Disease
Authors: Bittner D. M. , Bittner V. , Riepe M. W.
Published: December 2011

In the continuum of patients with Alzheimer's disease (AD), mild cognitive impairment (MCI), and normal controls, a possible association of verbal memory and endogenous estradiol (E2) levels was investigated. Verbal episodic memory was measured with a german version of the California verbal memory test (CVLT). Results were controlled for apolipoprotein E (ApoE) phenotype. We studied 37 controls, 32 MCIs and 117 ADs. Groups differed in all trials of the CVLT and in E2levels . E2 levels differed significantly between groups only among females . In females correcting for age and ApoE, there was an overall correlation between CVLT delayed recall and level of E2  . Stepwise regression analyses found E2level to be a significant predictor for CVLT delayed recall . It may be concluded that lower E2levels occur more in the course of the disease than may be considered as a risk factor per se.
Fuzzy Comprehensive Evaluation on the Effect of Measures Operation for Oil-Water Well
Authors: Liu Zhi-Bin , Qing Wei , Kong Xin-Hai
Published: December 2011

The measures operation is an important component of borehole operation, and the operation effects directly affect the increase of oil and gas production. In perspective of the present reality of borehole operation company, the authors analyze the commonly used type of measures on the oil field, summarize six indicators to evaluate the measures operation effect, and give the quantitative calculation method for six evaluation indicators. Through the experts grading method, we can obtain all the weights of indicators and then establish the fuzzy comprehensive evaluation model of operation effect of measures. The evaluation model can be used to evaluate the operation effect of single well, oil block, or the branch company. Based on the actual data of measures operation of a branch company, using the fuzzy comprehensive evaluation approach to evaluate each block in the branch company, this paper obtained the same conclusion as the qualitative analysis.
Familial Pulmonary Capillary Hemangiomatosis Early in Life
Authors: Wirbelauer Johannes , Hebestreit Helge , Marx Alexander , Mark Eugene J. , Speer Christian P.
Published: December 2011

Background. Pulmonary capillary hemangiomatosis (PCH) is a rare disease, especially in infancy. Four infants have been reported up to the age of 12 months. So far, no familial patients are observed at this age.Patients. We report three siblings, two female newborns and a foetus of 15-week gestation of unrelated, healthy parents suffering from histologically proven PCH. The first girl presented with increased O2requirements shortly after birth and patentductus arteriosus(PDA). She subsequently developed progressive respiratory failure and pulmonary hypertension and died at the age of five months. The second girl presented with clinical signs of bronchial obstruction at the age of three months. The work-up showed a PDA—which was surgically closed—pulmonary hypertension, and bronchial wall instability with stenosis of the left main bronchus. Transient oxygen therapy was required with viral infections. The girl is now six years old and clinically stable without additional O2requirements. Failure to thrive during infancy and a somewhat delayed development may be the consequence of the disease itself but also could be attributed to repeated episodes of respiratory failure and a long-term systemic steroid therapy. The third pregnancy ended as spontaneous abortion. The foetus showed histological signs of PCH.Conclusion. Despite the differences in clinical course, the trias of PCH, PDA, and pulmonary hypertension in the two life born girls suggests a genetic background.
Rosiglitazone and Pioglitazone Alter Aromatase Kinetic Properties in Human Granulosa Cells
Authors: Araki Takako , Varadinova Miroslava , Goldman Michael , Rosenwaks Zev , Poretsky Leonid , Seto-Young Donna
Published: December 2011

We have previously reported that, in human granulosa cells, thiazolidinediones rosiglitazone and pioglitazone inhibit estrogen synthesis by interfering with androgen binding to aromatase, without an effect on aromatase mRNA or protein expression. In the current paper, we explore the effects of rosiglitazone and pioglitazone on the aromatase enzyme kinetic properties in human granulosa cells. The cells were incubated with various concentrations of testosterone or androstenedione, with or without rosiglitazone or pioglitazone. Estradiol and estrone concentrations in the conditioned tissue culture medium were measured by radioimmunoassay or immunosorbent assay. When testosterone was used as substrate, rosiglitazone or pioglitazone inhibited theVmaxby 35% (P<0.001) and 24% (P<0.001), respectively. When androstenedione was used as substrate, both rosiglitazone or pioglitazone inhibitedVmaxby 13% (P<0.007). We conclude that rosiglitazone or pioglitazone has no effect onKmbut inhibitsVmaxof aromatase in human granulosa cells, therefore, acting as noncompetitive inhibitors.
The Evolving Paradigm in the Management of Intracranial Atherosclerotic Disease
Authors: Ozturk Ali K. , Bulsara Ketan R.
Published: December 2011

Intracranial atherosclerotic disease (ICAD) is a major cause of ischemic stroke worldwide and represents a significant health problem. The pathogenesis and natural history of ICAD are poorly understood, and rigorous treatment paradigms do not exist as they do for extracranial atherosclerosis. Currently, the best treatment for ICAD remains aspirin therapy, but many patients who are placed on aspirin continue to experience recurrent strokes. As microsurgical and endovascular techniques continue to evolve, the role of extracranial to intracranial bypass operations and stenting are increasingly being reconsidered. We performed a PubMed review of the English literature with a particular focus on treatment options for ICAD and present evidence-based data for the role of surgery and stenting in ICAD against medical therapy alone.
Massive Black Hole Binaries: Dynamical Evolution and Observational Signatures
Authors: Dotti M. , Sesana A. , Decarli R.
Published: December 2011

The study of the dynamical evolution of massive black hole pairs in mergers is crucial in the context of a hierarchical galaxy formation scenario. The timescales for the formation and the coalescence of black hole binaries are still poorly constrained, resulting in large uncertainties in the expected rate of massive black hole binaries detectable in the electromagnetic and gravitational wave spectra. Here, we review the current theoretical understanding of the black hole pairing in galaxy mergers, with a particular attention to recent developments and open issues. We conclude with a review of the expected observational signatures of massive binaries and of the candidates discussed in literature to date.
Chromosomal Instability Substantiates Poor Prognosis in Patients with Diffuse Large B-cell Lymphoma
Authors: Bakhoum Samuel F. , Danilova Olga V. , Kaur Prabhjot , Levy Norman B. , Compton Duane A.
Published: December 2011

Purpose: The specific role of chromosomal instability (CIN) in tumorigenesis has been a matter of conjecture. In part, this is due to the challenge of directly observing chromosome mis-segregation events as well as the inability to distinguish the role of CIN, which consists of increased rates of chromosome mis-segregation, from that of aneuploidy, which is a state of nondiploid chromosome number.

Experimental Design: Here, we examine the contribution of CIN to the prognosis of patients diagnosed with diffuse large B-cell lymphoma (DLBCL) by directly surveying tumor cells, fixed while undergoing anaphase, for evidence of chromosome mis-segregation. Hematoxylin and eosin–stained samples from a cohort of 54 patients were used to examine the relationship between frequencies of chromosome mis-segregation and patient prognosis, overall survival, and response to treatment.

Results: We show that a two-fold increase in the frequency of chromosome mis-segregation led to a 24% decrease in overall survival and 48% decrease in relapse-free survival after treatment. The HR of death in patients with increased chromosome mis-segregation was 2.31 and these patients were more likely to present with higher tumor stage, exhibit tumor bone marrow involvement, and receive a higher International Prognostic Index score.

Conclusions: Increased rates of chromosome mis-segregation in DLBCL substantiate inferior outcome and poor prognosis. This is likely due to increased heterogeneity of tumor cells leading to a larger predilection for adaptation in response to external pressures such as metastasis and drug treatments. We propose that targeting CIN would yield superior prognosis and improved response to chemotherapeutic drugs. Clin Cancer Res; 17(24); 7704–11. ©2011 AACR.
The Intertextual Production of International Relations in Mergers and Acquisitions
Authors: Riad Sally , Vaara Eero , Zhang Nathan
Published: December 2011

While studies on international management have focused on cultural differences and examined institutional specificities in various national business systems, conceptions of international relations have been left relatively underexplored. We argue that representations of international relations are relevant to international M&As and contend that intertextuality offers a novel approach to examine these relational features of international management. Our analysis focuses on Sino–US relations in the context of the acquisition of American IBM’s Personal Computer Division (PCD) by the Chinese company, Lenovo. We demonstrate the ways in which facets of international relations are produced in media accounts of this acquisition, and analyse the intertextual dynamics entwined with their production. The analysis consists of three sections: constitutive intertextuality, manifest intertextuality and intertextual ideological undercurrents. These illustrate the variation in producing international relations through discursive themes (threat to security/peaceful rise), emotion rhetoric (fear/cheer) and ideology (cold war/globalism). In summary, the paper elucidates the ways in which international M&As are immersed in a seascape of intertextual international relations.
Low-Frequency Ultrasound (20-40 kHz) as an Adjunctive Therapy for Chronic Wound Healing
Authors: Voigt Jeffrey , Wendelken Martin , Driver Vickie , Alvarez Oscar M.
Published: December 2011

Ultrasound as a therapeutic agent in chronic wound healing has been studied extensively. This systematic review and meta-analysis specifically examines low-frequency (20-30 kHz) ultrasound delivered at either low or high intensity. The objective of this review was to determine whether low-frequency ultrasound used as an adjunctive therapy improves the outcomes of complete healing and reduction of size of chronic lower limb wounds. PubMed, Cochrane/CENTRAL, technical assessment, relevant wound-related journals, and clinical guidelines were searched along with contacting manufacturers and authors of relevant randomized controlled trials were completed. Searches focused on the use of low-frequency ultrasound in randomized controlled trials. Data were collected via a data collection form and was adjudicated independently via coauthors. Meta-analyses and heterogeneity checks were performed using Mantel–Haenszel and inverse variance (fixed and random effects) statistical methods on studies with similar outcomes (complete healing and percent wound area reduction) over similar time periods. Single study results were reported via the statistical methods used in the study. Eight randomized controlled trials were identified. Results demonstrated that early healing (at ≤5 months) in patients with venous stasis and diabetic foot ulcers was favorably influenced by both high- and low-intensity ultrasound delivered at a low frequency—either via contact or noncontact techniques. However, the quality of the data may be suspect, especially for low-frequency low-intensity noncontact ultrasound because of significant biases. In patients presenting with either venous stasis or diabetic foot ulcers (Wagner classification 1-3), early healing appears to be facilitated by either low-frequency low-intensity noncontact ultrasound or low-frequency high-intensity contact ultrasound.
Animals, People and Places: The Continuity of Hunting and Gathering Practices across the Mesolithic-Neolithic Transition in Britain
Authors: Cummings Vicki , Harris Oliver
Published: December 2011

This article considers the long-debated and thorny issue of the transition from the Mesolithic to the Neolithic in Britain. The apparently polarised debate that has dominated this discussion is, we suggest, unhelpful, and rather than positing either total colonisation from abroad, or simple indigenous continuity, we propose a model where both incomers and autochthons had their part to play. To explore this further we trace continuities across the divide in practices of hunting and gathering, and place these alongside the demonstrable evidence for change.
Proteomic profiling of the mesenteric lymph after hemorrhagic shock: Differential gel electrophoresis and mass spectrometry analysis
Authors: Zurawel Ashley , Moore Ernest E , Peltz Erik D , Jordan Janeen R , Damle Sagar , Dzieciatkowska Monika , Banerjee Anirban , Hansen Kirk C
Published: December 2011

Experiments show that upon traumatic injury the composition of mesenteric lymph changes such that it initiates an immune response that can ultimately result in multiple organ dysfunction syndrome (MODS). To identify candidate protein mediators of this process we carried out a quantitative proteomic study on mesenteric lymph from a well characterized rat shock model. We analyzed three animals using analytical 2D differential gel electrophoresis. Intra-animal variation for the majority of protein spots was minor. Functional clustering of proteins revealed changes arising from several global classes that give novel insight into fundamental mechanisms of MODS. Mass spectrometry based proteomic analysis of proteins in mesenteric lymph can effectively be used to identify candidate mediators and loss of protective agents in shock models.
Ta-Chung Liu's Exploratory Econometrics
Authors: Chao Hsiang-Ke , Huang Chao-Hsi
Published: December 2011

This essay studies the contribution of Ta-Chung Liu to econometrics by focusing on the models and methods of Liu's econometric practices from the 1950s to the 1970s. We document his development of an exploratory econometric approach, a development he effected by experimenting with tools and elements in the model-building process and which led him finally to accept the recursive methodology represented by Herman Wold. We also discuss Liu's theoretical and empirical concerns for econometric models that spurred his involvement in a series of debates against the Cowles Commission approach in the 1960s and 1970s, and we discuss his legacy to contemporary econometrics.
Corrado Gini (1884–1965): The Leading Figure of the Italian Group in the Econometric Society
Authors: Parisi Daniela
Published: December 2011

This essay deals with some key Italian contributions to econometrics in the twentieth century. It opens with some notes on the need to define and measure each dimension of the manifold notion of well-being. While considering the convinced supporters of the methodological adoption of tools devised by economics and statistics, the central part of the essay focuses on Corrado Gini (1884–1965). He was Italy's leading econometrician and the main reference of the international network of econometricians until the 1940s. Other Italian members of the newly formed Econometric Society are also cited, specifically Luigi Amoroso and Umberto Ricci, because of the relevance of their contribution. The essay concludes by referring to Gini's rejection of econometrics, which coincided with the appearance of a new generation of social scientists whose aim was to combine economics, statistics, and mathematics.
A History of the Histories of Econometrics
Authors: Boumans Marcel , Dupont-Kieffer Ariane
Published: December 2011

Econometricians have from the start considered historical knowledge of their own discipline as reflexive knowledge useful for delineating their discipline, that is, for setting its disciplinary boundaries with respect to its aims, its methods, and its scientific values. As such, the histories written by econometricians reflect the scientific image of their discipline in a given period. Each image of a period is drawn by denominating forerunners and founding fathers and uses the language of the dominant philosophy of science of that day.

At the end of the nineteenth century, a scientific theory had to be mathematical; in the interbellum the image of science was that of logical positivism. In the 1970s and 1980s the dominant views were those of Karl Popper, Imre Lakatos, and Thomas Kuhn. Currently the scientific image in econometrics is the one of the Stanford school (Nancy Cartwright, Ian Hacking, and Patrick Suppes).
The Fellowship of Econometrics: Selection and Diverging Views in the Province of Mathematical Economics, from the 1930s to the 1950s
Authors: Louçã Francisco , Terlica Sofia
Published: December 2011

Two defining moments in the history of econometrics and in that of the Econometric Society are discussed in this essay. The first is the founding of the society and the initial skirmishes over the criteria for selecting its fellows, who were to represent the best practices of econometrics. The second was, twenty years later, the discussion about the nature of the mathematics adequate for the progress of econometrics. In both cases, some dissident views were presented, but whereas in the first period a pluralistic approach dominated, by the time of the second debate a more coherent and cohesive view was prevalent in econometric circles, to the discomfort of some of its founders.
Conflict as a “Normal Economic Activity”: The Contribution of Jack Hirshleifer, 1925–2005
Authors: Rangil Teresa Tomás
Published: December 2011

The writings of the American economist Jack Hirshleifer (1925–2005) are considered some of the most influential contributions to the economics of conflict. This article examines how Hirshleifer transformed the behavioral assumptions of Homo economicus (the self-interest model and the concept of rationality) to offer economically grounded explanations for conflicts. We explain how, through his interactions with sociobiologists and game theorists, he reduced self-interest to mere selfishness and redefined rationality to encompass emotions and feelings. The final result was a disciplinary reclassification of conflict as a subvariety of selfish, rational behavior amenable to economic analysis.
The number of women who would need to be screened regularly by mammography to prevent one death from breast cancer
Authors: Beral Valerie , Alexander Maggie , Duffy Stephen , Ellis Ian O , Given-Wilson Rosalind , Holmberg Lars , Moss Sue M , Ramirez Amanda , Reed Malcolm W R , Rubin Caroline , Whelehan Patsy , Wilson Robin , Young Kenneth C
Published: December 2011

The number of women who would need to be screened regularly by mammography to prevent one death from breast cancer depends strongly on several factors, including the age at which regular screening starts, the period over which it continues, and the duration of follow-up after screening. Furthermore, more women would need to be INVITED for screening than would need to be SCREENED to prevent one death, since not all women invited attend for screening or are screened regularly. Failure to consider these important factors accounts for many of the major discrepancies between different published estimates. The randomised evidence indicates that, in high income countries, around one breast cancer death would be prevented in the long term for every 400 women aged 50–70 years regularly screened over a ten-year period.
Removal of Reactive Brilliant Orange X-GN from Aqueous Solutions By Mg-Al Layered Double Hydroxides
Authors: Wu Pingxiao , Zhang Qian , Dai Yaping , Zhu Nengwu , Li Ping , Wu Jinhua , Dang Zhi
Published: December 2011

Among the many techniques used to remove toxic dyes from the environment, layered double hydroxides (LDH) are considered to be especially environmentally friendly, but, this quality may be altered by variations in the octahedral Mg/Al molar ratios in the LDH structure. The aim of the present study was to synthesize environmentally sound LDH for use as an economically viable sorbent for the adsorption of reactive brilliant orange X-GN. Layered double hydroxides with Mg/Al molar ratios of 2:1 and 4:1 were prepared by co-precipitation. The materials obtained were characterized by powder X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, X-ray fluorescence spectroscopy (XRF), and surface-area analysis. Batch experiments were carried out to investigate the effects of contact time, pH, adsorbent dosage, and initial dye concentration on the adsorption behavior of the reactive brilliant orange X-GN by Mg-Al LDH. The results showed that the optimum pH value for dye adsorption was 3.0, at which the adsorption capacities of the reactive brilliant orange X-GN by the 2:1 LDH and the 4:1 LDH at 298 K were 79.370 mg/g and 83.343 mg/g, respectively. Further analysis of the dye-adsorption kinetics show that they fit the pseudo second-order model well. The adsorption equilibrium data showed that the Langmuir model provided better correlation of the equilibrium data than the Freundlich model. This result indicates that LDH provide specific homogeneous sites where monolayer dye adsorption occurs. The results of XRD and FTIR analyses of LDH before and after the dye adsorption demonstrated that the adsorption mechanisms were ion exchange and coulombic attraction.
Synthesis, Characterization, and Visible-Light Photo-Fenton Catalytic Activity of Hydroxy Fe/Al-Intercalated Montmorillonite
Authors: Li Hailing , Wu Pingxiao , Dang Zhi , Zhu Nengwu , Li Ping , Wu Jinhua
Published: December 2011

The photochemically assisted Fenton reaction (photo-Fenton) is important because it may be particularly effective for the degradation of harmful organic compounds in the environment using solar light. The purpose of the present study was to determine the effectiveness of hydroxy Fe/Al-intercalated montmorillonites (Fe/Al-Mt) as photo-Fenton catalysts. In particular, different Fe/Al molar ratios were of interest as a means to vary catalytic activity. Intercalation was achieved via an ion-exchange method and brilliant orange X-GN was the test compound for photodegradation by hydrogen peroxide (H2O2) under visible-light irradiation (γ < 420 nm) in the presence of Fe/Al-Mt. The Fe/Al-Mt materials obtained were characterized by powder X-ray diffraction, N2 adsorption/desorption, X-ray fluorescence spectroscopy, X-ray photoelectron spectroscopic analysis, and ultraviolet-visible spectroscopy. The decoloration performance of Fe/Al-Mt was investigated using different experimental parameters, including the synthesis method, the Fe/Al molar ratio of the intercalating solution, the catalyst dosage, the H2O2 dosage, and the pH. The results of photo-Fenton reaction showed that the photocatalytic activity of Fe/Al-Mt was enhanced significantly by the extent of hydroxy Al/Fe intercalation. For optimal reaction conditions, 99.92% degradation efficiency of X-GN was achieved after 140 min of reaction. To obtain further information on the visible-light-assisted photo-Fenton process, a high-performance liquid chromatography-mass spectrometry method was applied to indentify the intermediate products and a degradation pathway was proposed.
Volcanism in Association with the Prelude to Mass Extinction and Environment Change Across the Permian-Triassic Boundary (PTB), Southern China
Authors: Hong Hanlie , Xie Shucheng , Lai Xulong
Published: December 2011

In order to better understand the provenance of the sediments and environmental change associated with the Permian-Triassic (P/T) biotic crisis, a comparative clay mineralogical study of the Permian-Triassic boundary (PTB) sediments between the Meishan section (the Global Stratotype Section and Point of the PTB) and the Xiakou section, southern China, was undertaken using X-ray diffraction and differential scanning calorimetry (DSC). The results showed that clay minerals of the packstone bed 24e, in which the preludial mass extinction occurred at Meishan, consist of 56% mixed-layer illite-smectite (I-S), 39% illite, and 5% kaolinite. A dehydroxylation effect was measured at 652°C, indicating that I-S and illite of this bed contain mainly cis-vacant (cv) layers related to volcanic origin. The dehydroxylation event correlates with bed P257 at Xiakou. The white clay bed 25 also corresponding to the main extinction event at Meishan contains 95% I-S and 5% kaolinite, with a strong endothermic effect at 676°C and a weaker one at 514°C in the DSC curve. These results are attributed to dehydroxylation of cv layers in I-S clays, suggesting that I-S in the white clay bed was derived from marine alteration of volcanic ash, in agreement with the conodont-correlated clay (P258) at Xiakou. (Conodonts are tooth-like microfossils and are usually used as an indicator of age in PTB stratigraphy.) Increases in chlorite and illite contents in the black clays (bed 26) at Meishan and the conodont-correlated black clay layer (P259b) at Xiakou probably indicate stronger erosional processes under cooler and more arid conditions. Volcanic materials found in a bed which marked the prelude to the main episode of mass extinction reinforce the temporal link between volcanism and the mass extinction.
Molecular Size Determination of Coal-Derived Asphaltene by Fluorescence Correlation Spectroscopy
Authors: Andrews A. Ballard , Shih Wei-Chuan , Mullins Oliver C. , Norinaga Koyo
Published: December 2011

The molecular properties of asphaltenes have been the subject of uncertainty in the literature; in particular the molecular architecture is still a matter of debate. Some literature reports provide evidence that the contrast of petroleum asphaltenes versus coal-derived asphaltenes is useful for understanding the governing principles of asphaltene identity. Here, we employ fluorescence correlation spectroscopy to measure the diffusion constants of asphaltenes obtained from the distillation resid from coal liquefaction fluids. Concentrations employed herein are ∼10−8 molar, precluding asphaltene aggregation. These are compared with the same measurements on petroleum asphaltenes. These results confirm that the molecular sizes of these coal-derived asphaltenes are much smaller than virgin petroleum asphaltenes. Coal-derived asphaltenes are simpler than petroleum asphaltenes and provide correspondingly tighter constraints for understanding asphaltene molecular architecture. The small size, small alkane fraction, and large PAH of coal-derived asphaltenes are consistent with an “island” molecular architecture.
Near-Infrared (NIR) Interactance System for Non-Contact Monitoring of the Temperature Profile of Baked Liver Pâté
Authors: O'Farrell Marion , Bakke Kari Anne Hestnes , Tschudi Jon , Wold Jens Petter
Published: December 2011

This article investigates the possibility of using non-contact interactance as a method for profiling the temperature in a processed meat product (liver pâté) as it comes out of the oven. The application was defined by an industrial partner, Nortura SA, Tønsberg, Norway, where more control of the cooking process was desired. The optical system employs low spectral resolution to achieve high enough signal-to-noise ratio (SNR) to depths of 2 cm into the product. The partial least squares (PLS) method was applied to interactance spectra in the region 760–1040 nm and a root mean square error of 1.52 °C was obtained. The model was tested on five different validation sets spread over 18 months and a root mean square error of prediction of 2.66 °C was achieved. The output of this model was based on the weighted average of two temperatures in the first 2 cm of the liver pâté, one of which is the core temperature. A comparison was also made with two other models: a model based on the core temperature alone and a model based again on the weighted temperature but using the shorter wavelength range of 905.5–1047 nm. These two models gave less favorable prediction errors.
Simultaneous Surface-Enhanced Raman Spectroscopy (SERS) and Atomic Force Microscopy (AFM) for Label-Free Physicochemical Analysis of Lipid Bilayers
Authors: Sweetenham Claire S. , Larraona-Puy Marta , Notingher Ioan
Published: December 2011

Large-scale two-dimensional (2D) arrays of metallic nanostructures formed by thin-film evaporation over hexagonally close-packed polystyrene spheres are established substrates for surface-enhanced Raman spectroscopy (SERS). By using these substrates with an integrated atomic force microscopy (AFM) and inverted Raman spectroscopy system, simultaneous topographical imaging and high-sensitivity chemical mapping can be performed. In this paper, we have used this technique to investigate supported bilayers of long-chain fatty acids and phospholipids deposited by the Langmuir–Blodgett (LB) and spin-coating techniques. Nanosphere lithography (NSL) substrates created from 384 and 1002 nm polystyrene spheres and silver (Ag) deposition on glass and sapphire substrates were characterized for SERS in terms of their structure, distribution, and level of enhancement. SERS mappings of rhodamine 6G (R6G) and p-aminothiophenol (p-ATP) monolayers on the 384 nm substrates demonstrate high and uniform enhancement at a micrometer scale. The enhancement was sufficiently high to enable measurement of SERS spectra for arachidic acid (AA) and dipalmitoylphosphatidylcholine (DPPC) layers on sapphire/Ag substrates. The roughness of these substrates (<2 nm) was lower than for glass/Ag (∼5 nm); therefore, simultaneous to SERS it was possible to measure the topography of the samples by AFM and determine the number of layers of AA and DPPC. This study shows the potential of the combined AFM/SERS technique for spectral and topographical characterization of phospholipid bilayers. This may prove to be an interesting approach for further studies with more complex heterogeneous lipid mixtures aiming to measure spatially resolved features such as microdomains.
Size-Resolved Source Apportionment of Aerosol Particles with a Confocal Micro X-Ray Fluorescence Spectrometer
Authors: Sun Tianxi , Liu Zhiguo , Li Yude , Ma Yongzhong , Wang Guangfu , Zhu Guanghua , Xu Qing , Lin Xiaoyan , Luo Ping , Pan Qiuli , Liu Hui , Teng Yuepeng , Ding Xunliang
Published: December 2011

A laboratory confocal micro X-ray fluorescence (micro-XRF) spectrometer based on a polycapillary focusing X-ray lens (PFXRL) in the excitation channel and a polycapillary parallel X-ray lens (PPXRL) in the detection channel was used to carry out the size-resolved source apportionment of aerosol particles. The PPXRL in the detection channel both increased the collection angle of the detector and improved the signal-to-noise ratio of the X-ray spectrum. When this confocal micro-XRF spectrometer was used to carry out the quantitative XRF analysis of single aerosol particles with smaller size than that of the overlapping foci of the PFXRL and the PPXRL, the sensitivity was corrected by using a Gaussian function. The size-resolved “fingerprint database” for the air pollution sources was established based on the quantitative XRF results for single aerosol particles. The size-resolved aerosol particles on hazy-foggy days in Beijing were apportioned.
Spectral Inter-Conversion Analysis of Conformational Defects in Polyethylene Crystals
Authors: Zhang Liping , Watanabe Shin , Noda Isao , Wu Yuqing
Published: December 2011

Conformational discrimination of polyethylene crystals during a heating process was carried out using a novel spectral inter-conversion analysis based on the combination of near-infrared (NIR) and mid-infrared (mid-IR) spectroscopy. Two mid-IR and two NIR spectral ranges relating to different conformational sequences were explored at 710–752 cm−1 and 4300–4362 cm−1 (corresponding to the orthorhombic), and 1328–1374 cm−1 (relating to the defect) and 4235–4295 cm−1 (corresponding to the unconfirmed conformation). Five partial least squares-2 (PLS-2) models were built based on these four infrared spectral ranges and were used to make the basis for spectral inter-conversion analysis. By comparing the conformational disordering induced by thermal stimulus, the attribution of an obscure NIR band at 4265 cm−1 was confirmed. The temperature dependency of the band at 4265 cm−1 in the NIR range was very similar to that of the bands at 1368, 1353, and 1341 cm−1 in the mid-IR range, indicating they had a common spectral origin. The band intensity at 4265 cm−1 was also extracted from the predicted spectra and compared with the intensity of the measured spectra. The excellent matching in the trend of intensity changes with temperature further demonstrated the same vibrational origin of the NIR band at 4265 cm−1 with respect to the mid-IR bands at 1368, 1353, and 1341 cm−1. The quantitative comparison of the prediction deviation values between different multivariate spectral models further validate the assignment of the band at 4265 cm−1 to the conformational defect sequence formed in the heating process.
Perichromism: A Novel, Rapid, Spectroscopic Technique to Distinguish between Amorphous and Crystalline Material
Authors: Major Patrick J. , Wicks Stephen R. , Alexander Bruce D. , Mitchell John C.
Published: December 2011

There are currently no techniques that allow facile on-line determination between amorphous and crystalline material. Herein, a new colorimetric method, perichromism, has been developed to distinguish between amorphous and crystalline material, based on diffuse reflection ultraviolet–visible (UV-visible) spectroscopy. A probe molecule, phenol red, at 0.1% w/w concentration was added to sucrose and dissolved in water. The solution was freeze-dried, which resulted in an amorphous excipient with the probe molecule incorporated in an intimate mixture. The samples were then stored at a selected controlled temperature and relative humidity to allow control of crystallization of the sucrose. The amorphous or crystalline nature of each sample, both with and without the addition of the phenol red probe molecule, was monitored through X-ray diffraction, differential scanning calorimetry, and Raman spectroscopy. It was found that sucrose remained amorphous when stored in an atmosphere with a relative humidity below 32%; above this level, crystallization occurred. It was found that the presence of the probe molecule did not alter the extent of crystallinity of sucrose. Analysis of the samples containing the phenol red probe by diffuse reflection spectroscopy revealed that spectra could be classified into two groups depending on the λmax. Furthermore, correlation of the diffuse reflection spectra with X-ray diffraction and differential scanning calorimetry data showed that sucrose was amorphous in one group and crystalline in the other group, thereby revealing that diffuse reflection spectroscopy can, when phenol red is used as a probe molecule, quickly and easily determine whether sucrose is crystalline or amorphous.