bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimating the distance to a monotone function
Authors: Ailon Nir , Chazelle Bernard , Comandur Seshadhri , Liu Ding
Published: February 2007

In standard property testing, the task is to distinguish between objects that have a property 𝒫 and those that are ε‐far from 𝒫, for some ε > 0. In this setting, it is perfectly acceptable for the tester to provide a negative answer for every input object that does not satisfy 𝒫. This implies that property testing in and of itself cannot be expected to yield any information whatsoever about the distance from the object to the property. We address this problem in this paper, restricting our attention to monotonicity testing. A function f : {1,…,n} ↦ R is at distance εf from being monotone if it can (and must) be modified at εfn places to become monotone. For any fixed δ > 0, we compute, with probability at least 2/3, an interval [(1/2 − δ)ε,ε] that encloses εf. The running time of our algorithm is O(εf−1 log log εf− 1 log n), which is optimal within a factor of loglog εf−1 and represents a substantial improvement over previous work. We give a second algorithm with an expected running time of O(εf−1 log nlog log log n). Finally, we extend our results to multivariate functions. © 2007 Wiley Periodicals, Inc. Random Struct. Alg., 2007
Large‐deviations/thermodynamic approach to percolation on the complete graph
Authors: Biskup Marek , Chayes Lincoln , Smith S. A.
Published: February 2007

We present a large‐deviations/thermodynamic approach to the classic problem of percolation on the complete graph. Specifically, we determine the large‐deviation rate function for the probability that the giant component occupies a fixed fraction of the graph while all other components are “small.” One consequence is an immediate derivation of the “cavity” formula for the fraction of vertices in the giant component. As a byproduct of our analysis we compute the large‐deviation rate functions for the probability of the event that the random graph is connected, the event that it contains no cycles and the event that it contains only small components. © 2007 Wiley Periodicals, Inc. Random Struct. Alg., 2007
Identification of Active Biomolecules in the High‐Yield Synthesis of Single‐Crystalline Gold Nanoplates in Algal Solutions
Authors: Xie Jianping , Lee Jim Yang , Wang Daniel I. C. , Ting Yen Peng
Published: February 2007

In this work, single‐crystalline gold nanoplates were produced by treating an aqueous solution of chloroauric acid with the extract of the unicellular green alga Chlorella vulgaris at room temperature. The results suggest proteins as the primary biomolecules involved in providing the dual function of AuIII reduction and the size‐ and shape‐controlled synthesis of the nanogold crystals. A protein with a molecular weight of approximately 28 kDa was isolated and purified by reversed‐phase HPLC; this protein tested positive for the reduction of chloroauric acid in aqueous solution. The isolated protein (named gold shape‐directing protein, or GSP for convenience) was then used to produce gold nanoplates with distinctive triangular and hexagonal shapes in high yields (≈90 %). The kinetics of the reduction reaction could be manipulated through changes in the GSP concentration to produce plates with lateral sizes ranging from nanometers to micrometers. The growth of gold nanoplates in the GSP solution with time was monitored by microscopic and spectroscopic techniques, thereby allowing the detection of several key intermediates in the growth process.
Starch Derivatives of High Degree of Functionalization. 13. Novel Amphiphilic Starch Products
Authors: Heinze Thomas , Rensing Stephan , Koschella Andreas
Published: February 2007

Amphiphilic starch derivatives of high degree of substitution (DS) were prepared by benzylation of pea, potato and waxy maize starch followed by the introduction of hydroxypropyltrimethylammonium and carboxymethyl moieties. The conversions were carried out under heterogeneous conditions leading to products with a total DS of up to 1.8. The starch composition regarding amylose and amylopectin influences the DS value.

The structure of the products was characterized by means of elemental analysis, FTIR and NMR spectroscopy, and, in case of benzyl carboxymethyl starch by means of HPLC after complete chain degradation. The tensioactive properties depend on the DS values of hydrophilic and lipophilic groups and can be adjusted by controlling the molar ratio anhydroglucose unit to reagent during the synthesis. Surface tensions as low as 48.6 mN/m were found for benzyl hydroxypropyltrimethylammonium starch and 38.6 mN/m for benzyl carboxymethyl starch. The lowest critical micelle concentration determined is 2.1 mmol/L.
Interaction of methylmercury and selenium on the bioaccumulation and histopathology in medaka (Oryzias latipes)
Authors: Liao Chun‐Yang , Zhou Qun‐Fang , Fu Jian‐Jie , Shi Jian‐Bo , Yuan Chun‐Gang , Jiang Gui‐Bin
Published: February 2007

Interaction of methylmercury and selenium in medaka (Oryzias latipes) on bioaccumulation of pollutants and histopathological changes in liver and gill were studied. Juvenile medaka fish were submitted to a series of waterborne methylmercury chloride (MMC), sodium selenite (Na2SeO3) and their mixture for 210 days, respectively. The methylmercury (MeHg) and selenium contents in the whole body of medaka were determined. The dose‐ and time‐dependent increase of MeHg and selenium contents in medaka were observed. Histopathological changes, such as edema, vacuoles, pyknotic nucleus, and telangiectasis, could clearly be observed in the slices from the exposed medaka's liver and gill. Concurrent exposure to MMC and Na2SeO3 showed the increased selenium accumulation. When the exposure molar ratio of MeHg:Se was about 1, the interaction between MeHg and selenium offered a limited protection against the serious intoxication of both MMC and Na2SeO3 to medaka. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 69–77, 2007.
Assessment of the potential toxicity of herbicides and their degradation products to nontarget cells using two microorganisms, the bacteria Vibrio fischeri and the ciliate Tetrahymena pyriformis
Authors: Bonnet J.‐L. , Bonnemoy F. , Dusser M. , Bohatier J.
Published: February 2007

The potential toxicity of several herbicides—alachlor, diuron and its photo and biotransformation products, glyphosate and its metabolite aminomethyl phosphonic acid (AMPA)—to nontarget cells was assessed using two microorganisms frequently used in ecotoxicology, Vibrio fischeri and Tetrahymena pyriformis. Toxicity assays involved the Microtox® test, the T. pyriformis population growth impairment test employing three different processes (flasks, tubes, microplates), and the T. pyriformis nonspecific esterase activities test. Several IC50 or EC50 values are reported for each molecule. Alachlor exerted a toxic effect on the two nontarget cells used. The results for diuron and its photo and biotransformation products indicated that most of the metabolites presented nontarget toxicity higher than that of diuron. Glyphosate and AMPA had a less negative effect on T. pyriformis than on V. fischeri. Nevertheless, in all cases, glyphosate was found to be more toxic than AMPA. Comparison analysis of the sensitivity of the different tests showed that, in general, tests using the eukaryotic cell (T. pyriformis) were more sensitive than test using the prokaryotic cell (V. fischeri), and that a population growth criterion is more sensitive than an enzymatic criterion. The three different processes that could be used to evaluate effects on population growth rate were equally sensitive for the herbicides tested. A significant correlation between toxicity data and the hydrophobicity of the chemicals could only be established with the growth population test. This study demonstrates that it is essential to assess the toxicity of the metabolites formed to complete a more comprehensive study of the environmental impact of a polluting agent. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 78–91, 2007.
Effect of dietary copper deficiency on iron metabolism in the pregnant rat
Authors: Andersen Henriette S. , Gambling Lorraine , Holtrop Grietje , McArdle Harry J.
Published: February 2007

Cu and Fe metabolism are known to be linked, but the interactions during pregnancy are less well studied. In the present study we used rats to examine the effect of Cu deficiency during pregnancy on Fe and Cu levels in maternal and fetal tissue and on the gene expression profile of proteins involved in Cu and Fe metabolism in the placenta. Rats were fed diets with different Cu contents before and during pregnancy. Samples were collected on day 21 of gestation. Cu levels, ceruloplasmin activity and serum Fe all decreased in maternal serum of Cu-deficient animals. Maternal liver Fe inversely correlated with liver Cu. Placental Cu levels decreased with no change in Fe. Fe and Cu levels both decreased in the fetal liver. The drop in maternal liver Cu was significantly correlated with a decrease in organ weight of fetal liver, lung and kidney. No changes were observed in mRNA expression of Cu transporter 1, Menkes P-type Cu-ATPase 7A, Wilson P-type Cu-ATPase 7B, cytochrome-c oxidase, and Cu chaperone Atox1 in the placenta of Cu-deficient dams. Transferrin receptor 1 and the Fe-responsive element (IRE)-regulated divalent metal transporter 1 (DMT1) were up regulated; while ferroportin and non-IRE1-regulated DMT1 levels did not change. These data show that Cu deficiency during pregnancy not only has a direct effect on Fe levels but also regulates the expression of Fe transporters. The pattern closely mirrors that seen in Fe deficiency, suggesting that the changes are a consequence of the decrease in serum Fe, implying that the developing fetus not only suffers from Cu, but also from Fe deficiency.
Long-term weight maintenance and cardiovascular risk factors are not different following weight loss on carbohydrate-restricted diets high in either monounsaturated fat or protein in obese hyperinsulinaemic men and women
Authors: Keogh Jennifer B. , Luscombe-Marsh Natalie D. , Noakes Manny , Wittert Gary A. , Clifton Peter M.
Published: February 2007

The aim of this study was to determine after 52 weeks whether advice to follow a lower carbohydrate diet, either high in monounsaturated fat or low fat, high in protein had differential effects in a free-living community setting. Following weight loss on either a high monounsaturated fat, standard protein (HMF; 50 % fat, 20 % protein (67 g/d), 30 % carbohydrate) or a high protein, moderate fat (HP) (40 % protein (136 g/d), 30 % fat, 30 % carbohydrate) energy-restricted diet (6000 kJ/d) subjects were asked to maintain the same dietary pattern without intensive dietary counselling for the following 36 weeks. Overall weight loss was 6·2 (sd 7·3) kg (P < 0·01 for time with no diet effect, 7·6 (sd 8·1) kg, HMF v. 4·8 (sd 6·6) kg, HP). In a multivariate regression model predictors of weight loss at the end of the study were sex, age and reported percentage energy from protein (R2 0·22, P < 0·05 for the whole model). Fasting plasma insulin decreased (P < 0·01, with no difference between diets), 13·9 (sd 4·6) to 10·2 (sd 5·2) mIU/l, but fasting plasma glucose was not reduced. Neither total cholesterol nor LDL-cholesterol were different but HDL was higher, 1·19 (sd 0·26) v. 1·04 (sd 0·29) (P < 0·001 for time, no diet effect), while TAG was lower, 1·87 (sd 1·23) v. 2·22 (sd 1·15) mmol/l (P < 0·05 for time, no diet effect). C-reactive protein decreased (3·97 (sd 2·84) to 2·43 (sd 2·29) mg/l, P < 0·01). Food records showed that compliance to the prescribed dietary patterns was poor. After 1 year there remained a clinically significant weight loss and improvement in cardiovascular risk factors with no adverse effects of a high monounsaturated fat diet.
Homocysteine levels in children and adolescents are associated with the methylenetetrahydrofolate reductase 677C>T genotype, but not with physical activity, fitness or fatness: The European Youth Heart Study
Authors: Ruiz Jonatan R. , Hurtig-Wennlöf Anita , Ortega Francisco B. , Patterson Emma , Nilsson Torbjörn K. , Castillo Manuel J. , Sjöström Michael
Published: February 2007

To examine the associations of total plasma homocysteine (tHcy) with physical activity, cardiorespiratory fitness and fatness in children and adolescents, a cross-sectional study of 301 children (9–10 years old) and 379 adolescents (15–16 years old) was conducted. Physical activity was measured by accelerometry. Cardiorespiratory fitness was measured with a maximal ergometer bike test. Body fat was derived from the sum of five skinfold thicknesses. Genotyping for the methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphism was done by DNA sequencing. Fasting tHcy level was the outcome variable. Multiple regressions were used to determine the degree to which variance in tHcy was explained by physical activity, cardiorespiratory fitness and body fat, after controlling for potential confounders including MTHFR 677C>T genotype. tHcy levels were neither associated with any measure of level and pattern of physical activity nor with data on cardiorespiratory fitness, or body fat, in any age group after controlling for potential confounders including MTHFR 677C>T and even when subgroups 677TT and 677CC+CT were analysed separately. Mean values of tHcy were significantly higher in the TT subgroup compared with CC and CT subgroups in children (TT 7·4 μmol/l, CC 6·3 μmol/l, CT 6·6 μmol/l,P < 0·001 andP = 0·019, respectively) and adolescents (TT 16·9 μmol/l, CC 8·3 μmol/l, CT 9·0 μmol/l, bothP < 0·001). The results suggest that physical activity, fitness and body fat are not associated with tHcy levels in children and adolescents, even after controlling for presence of the MTHFR 677C>T genotype, the main influence on tHcy levels in these subjects.
Serum selenium concentrations and dietary selenium intake of New Zealand children aged 5–14 years
Authors: Thomson Christine D. , McLachlan Sarah K. , Parnell Winsome R. , Wilson Noela , Wohlers Mark , Scragg Robert , Schaaf David , Fitzgerald Eljon D.
Published: February 2007

Serum Se concentrations and dietary Se intakes have been determined in relation to age, sex, ethnicity, region and index of deprivation in a nationally representative sample of New Zealand children aged 5–14 years from the 2002 National Children's Nutrition Survey. Dietary intake was assessed from computer-assisted, multiple-pass 24 h diet recall interviews (n3275). Serum Se concentrations were obtained from a subset of urban-based children (n1547). Mean (95 % CI) serum Se concentration in children was 0·96 (0·93, 1·00) μmol/l. Males (1·00 μmol/l) had higher serum Se levels than females (0·93 μmol/l;P = 0·027). Mäori children had lower serum Se than Pacific Islands children (P = 0·038) and New Zealand European and Other children (P = 0·005). Children in the Upper North Island (1·06 μmol/l) had higher mean serum Se values than those in the Lower North Island (0·98 μmol/l,P < 0·0005) and South Island (0·79 μmol/l,P < 0·0005), and serum Se in the Lower North Island was higher than that in the South Island (P < 0·0005). Mean dietary Se intake was 36 (34, 37) μg/d. The intakes of children aged 5–6 years (31 μg/d) were lower than those of children aged 7–10 and 11–14 years (35 and 38 μg/d, respectively;P < 0·00 005) and the intakes of 7–10-year-olds were lower than those of 11–14-year-olds (P = 0·002). Serum Se was associated with dietary Se after adjusting for all variables, including region (P = 0·006). The Se status of our children falls in the middle of the international range of serum Se concentrations, but that for children in the South Island is among the lowest values reported and may be a cause for concern.
Comparative assessment of feeding damage by pod-sucking bugs (Heteroptera: Coreoidea) associated with cowpea, Vigna unguiculata ssp. unguiculata in Nigeria
Authors: Soyelu O.L. , Akingbohungbe A.E.
Published: February 2007

Feeding trials were conducted on three (young, mid-fill and mature) developmental stages of cowpea Vigna unguiculata ssp. unguiculata pods in the screenhouse using fourth instar nymphs and adults of Anoplocnemis curvipes (Fabricius), Riptortus dentipes (Fabricius), Mirperus jaculus (Thunberg), Clavigralla tomentosicollis Stål and C. shadabi Dolling. Anoplocnemis curvipes was observed to be the most damaging coreoid species causing a yield reduction of 26.4–51.7% followed by R. dentipes (24.4–29.4%), M. jaculus (21.9–26.9%), C. tomentosicollis (17.9–22.4%) and C. shadabi (15.9–20.4%). The fourth instar nymphs of each pod-sucking bug species caused a significantly higher cowpea yield reduction than their respective adults. Similarly, infestation on young pods compared to mid-fill and mature stages resulted in significantly higher yield reduction. The results suggest that infestation levels of two fourth instar nymphs of A. curvipes or three fourth instar nymphs of the other four pod-sucking bug species per young pod should be adequate for screening of cowpea varieties for resistance to the coreoid bugs.
Effect of storage temperature and duration on viability of eggs of Helicoverpa armigera (Lepidoptera: Noctuidae)
Authors: Dhillon M.K. , Sharma H.C.
Published: February 2007

The ability to store different insect stadia for prolonged periods provides considerable flexibility and ability to conduct experiments properly. Therefore, studies were undertaken to determine the effect of storage temperature and duration on viability of eggs of Helicoverpa armigera (Hübner). The percentage egg hatch and incubation period were significantly (P=0.01) influenced by egg age, storage temperature, and storage duration. Egg hatch ranged from 0.0 to 96.8% across temperatures and storage durations. None of the eggs hatched when stored at −20 and 0°C. The regression model with the optimum Mallow Cp statistic for any of the identified linear and quadratic terms did not improve the precision of prediction in egg hatch beyond 67.0%. Forecasting of incubation period based on egg age, storage duration, and duration×temperature was quite effective (R2=84.2%). Day degrees required for egg hatching decreased with an increase in temperature from 10 to 27°C, and egg age from 0 to 3 days. The day degree requirements were highest for 0-day-old eggs at 10°C, and lowest at 27°C. Although the incubation period was higher, the hatchability was lower for 0- and 1-day-old eggs stored at constant 10°C, these eggs can be stored for 10 days at 10°C, with a hatchability of >75.0%. It was safer to store the H. armigera eggs for 10 days at 10°C, which will hatch within 1.6 to 2.0 days after restoration at 27°C with a hatchability of >75.0%. This information will be useful in planning and execution of experiments involving H. armigera on various aspects of research in entomology.
Phenotypic plasticity of pigmentation and morphometric traits inPnigalio soemius(Hymenoptera: Eulophidae)
Authors: Bernardo U. , Pedata P.A. , Viggiani G.
Published: February 2007

Species of the genusPnigalioSchrank are ectoparasitoids on several pest insects. Most species are polyphagous parasitoids of lepidopteran and dipteran leafminers. Despite their potential economic importance, information on intraspecific phenotypic variability is insufficient.Pnigalio soemius(Walker) was reared at five different temperatures (10, 15, 20, 25, 30°C) on mature larvae of one of its natural hosts,Cosmopterix pulchrimellaChambers (Lepidoptera: Cosmopterigidae), to investigate the influence of temperature on size, colour and other morphological traits, and to measure the range of variation of several characters. Thermal developmental reaction norms, which represent the effect of temperature during growth and development on the value of some adult traits, were produced. The results confirmed the influence of temperature on numerous characters and that these characters had a larger range of variation than realized previously in the construction of taxonomic keys to species. In particular, the number and position of the costulae on the propodeum and colour of the gaster were affected by rearing temperature.
‘Depoliticisation’ in the Reform of the Panamanian Security Apparatus
Authors: CAUMARTIN CORINNE
Published: February 2007

This article examines the unusual public security reform process that took place in Panama in the wake of the US military invasion of December 1989. The changes to the Panamanian security forces that ensued were in equal part a ‘demilitarisation’ process, a police reform and an (imposed) transition to democracy where the political domination of the Panamanian security forces came to an abrupt end. Deploying the concepts of demilitarisation, professionalisation and depoliticisation, the article evaluates the political role and activities of police forces and the nature of their relationship with the main Panamanian political actors through to the present Torrijos administration. It then assesses the implications for wider political processes, suggesting that explanations for the success or failure of reform are unlikely to be found in the examination of the design and implementation of the reform itself, but that broader political processes must be analysed in order to understand the dynamic that underpins it.
A novel automatic cooking robot for Chinese dishes
Authors: Yan W. X. , Fu Z. , Liu Y. H. , Zhao Y. Z. , Zhou X. Y. , Tang J. H. , Liu X. Y.
Published: February 2007

Up to now, most people are still cooking in the kitchen, which makes them feel fatigued and also makes the air polluted. With the development of the numerical control technology, it becomes more and more urgent to apply the related technology to the automatic cooking field. In this paper, the cooking technique for the Chinese dishes is introduced and China's first cooking robot, named AI Cooking Robot (AIC), is presented. The robot mainly consists of four parts: the wok mechanism, the stirring-fry and dispersing mechanism, the feeding mechanism, and the mechanism of leaving the material in the middle process. In order to adjust the temperature, the fire control system is also given in this paper. Experiments show that the new robot will be a milestone in the cooking automation science because of its cooking technique.
Wigner–von Neumann perturbations of a periodic potential: spectral singularities in bands
Authors: KURASOV PAVEL , NABOKO SERGUEI
Published: February 2007

Wigner–von Neumann type perturbations of the periodic one-dimensional Schrödinger operator are considered. The asymptotics of the solution to the generalized eigenfunction equation is investigated. It is proven that a subordinated solution and therefore an embedded eigenvalue may occur at the points of the absolutely continuous spectrum satisfying a certain resonance (quantization) condition between the frequencies of the perturbation, the frequency of the background potential and the corresponding quasimomentum.
Zeros of differences of meromorphic functions
Authors: BERGWEILER WALTER , LANGLEY J. K.
Published: February 2007

Let f be a function transcendental and meromorphic in the plane, and define g(z) by g(z) = Δf(z) = f(z + 1) − f(z). A number of results are proved concerning the existence of zeros of g(z) or g(z)/f(z), in terms of the growth and the poles of f. The results may be viewed as discrete analogues of existing theorems on the zeros of f' and f'/f.
Risk factors for community-acquired pneumonia in German adults: the impact of children in the household
Authors: SCHNOOR M. , KLANTE T. , BECKMANN M. , ROBRA B. P. , WELTE T. , RASPE H. , SCHÄFER T. ,   The CAPNETZ Study Group
Published: February 2007

The objective of this case-control study was to identify the main risk factors for community-acquired pneumonia (CAP) in a German adult population. A self-administered questionnaire was given to CAP cases provided by the German competence network CAPNETZ and population-based, randomly selected controls (sex- and age-matched). Multivariate analysis showed that in addition to known risk factors such as previous CAP [odds ratio (OR) 1·6, 95% confidence interval (CI) 1·3–2·1], more than one respiratory infection during the previous year (OR 3·6, 95% CI 2·9–4·5), chronic pulmonary diseases (OR 2·3, 95% CI 1·7–3·0), number of comorbidities (OR 1·6, 95% CI 1·4–1·9), and number of children in the household (2 children: OR 2·2, 95% CI 1·5–3·4; ⩾3 children: OR 3·2, 95% CI 1·5–7·0) were independent risk factors for CAP. This was pronounced in particular in people aged ⩽65 years. The most likely explanation for this finding is higher exposure to infectious agents.
IN DEFENCE OF THE SOVEREIGNTY OF PHILOSOPHY: AL-BAGHDĀDĪ'S CRITIQUE OF IBN AL-HAYTHAM'S GEOMETRISATION OF PLACE
Authors: EL-BIZRI NADER
Published: February 2007

This paper investigates the objections that were raised by the philosopher ‘Abd al-Laṭīf al-Baghdādī (d. ca. 1231 CE) against al-Ḥasan ibn al-Haytham’s (Alhazen; d. after 1041 CE) geometrisation of place. In this line of enquiry, I contrast the philosophical propositions that were advanced by al-Baghdādī in his tract: Fī al-Radd ‘alā Ibn al-Haytham fī al-makān (A refutation of Ibn al-Haytham’s place), with the geometrical demonstrations that Ibn al-Haytham presented in his groundbreaking treatise: Qawl fī al-Makān (Discourse on place). In examining the particulars of al-Baghdādī’s fragile defence of Aristotle’s definition of topos as delineated in Book IV of the Physics, which was rejected on mathematical grounds by Ibn al-Haytham, a special attention is also given to highlighting the systemic distinctions between the entities that are studied within the speculative physical doctrines of common sense and immediate experience, and the postulated ‘objects’ of scientific and mathematical research.
L'ALGÈBRE ARABE DANS LES TEXTES HÉBRAÏQUES (II). DANS L'ITALIE DES XVe ET XVIe SIÈCLES, SOURCES ARABES ET SOURCES VERNACULAIRES
Authors: LÉVY TONY
Published: February 2007

Until the end of the 14th century, the sources of Hebrew mathematical writings were almost exclusively in Arabic. This was particularly true of texts that contained elements of algebra or algebraic developments. The testimonies we present and analyze here are due to Jewish authors living in Italy, primarily in the 15th century, who made use of the most varied sources, in addition to Arabic: in Castilian, in Italian, and perhaps in Latin. These testimonies constitute both an indication, and a product, of the circulation of Arab algebraic traditions in Renaissance Italy. Simon Moṭoṭ’s book on The Calculation of Algebra stems from the Italian tradition of ‘‘treatises on the abacus’’. Mordekhay Finzi of Mantua is the author of a Hebrew version of the great work on algebra by Abū Kāmil (9th century), as well as of a version, distinct from the preceding, of the Arabic scholar’s introductory exposition. Beginning in 1473, Finzi also translated from Italian to Hebrew the important treatise on algebra by Maestro Dardi of Pisa (1344). We also indicate some 16th century continuations of Hebrew mathematical production, which contain algebraic developments.
Decentralized investment management: an analysis of non-profit pension funds
Authors: BATEMAN HAZEL , THORP SUSAN
Published: February 2007

We investigate delegated investment management in private pension accounts using data from Australian accumulation (superannuation) funds. In Australian non-profit pension funds, trustees choose investment managers on behalf of members. We find that funds with many delegated managers have higher risk-adjusted returns than those with few. However funds with 13 or less specialized managers show no improvement over funds with a single diversified manager. All do worse than a benchmark portfolio of asset-class indices. Further, by using random selection to mimic the choices of an uninformed individual choosing from the same menu of delegate managers as used by trustees, we show that returns from pension funds with large numbers of trustee-selected managers compare favorably with returns from randomly selected, equally weighted portfolios. However this improvement falls off quickly for funds with fewer trustee-selected managers, or when randomly selected portfolios are also diversified across asset classes. Results indicate that an uninformed individual following a naive diversification strategy would have done as well as most trustee boards in this sample.
Private pensions and government guarantees: clues from Canada
Authors: NIELSON NORMA L. , CHAN DAVID K. W.
Published: February 2007

The Pension Benefits Guarantee Fund (PBGF) was established in the province of Ontario in 1980, thus creating in Canada a rare opportunity for intranational empirical research on the impacts of governmental protection on private plans and their participants. This paper examines Canadian data on pension plans for effects attributable to Ontario's government guarantees for some plans. We find that significant variables related to an increase in the number of pension plans in Canada are higher interest rates, a larger labour market, and, consistent with the deferred compensation theory from labour economics, lower real disposable income of workers. The number of members in pension plans is related significantly to the same variables and also to tax rates and unemployment. The analyses show that the Ontario environment for pension plans is significantly different from the rest of Canada. Those plans covered by the Pension Benefit Guarantee Fund exhibit a lower degree of funding per participant than do the remainder of the plans in the sample, supporting the argument that a government guarantee is related to a moral hazard problem in Ontario pension financing.
On the sensitivity of radiative forcing from biomass burning aerosols and ozone to emission location
Authors: Naik Vaishali , Mauzerall Denise L. , Horowitz Larry W. , Schwarzkopf M. Daniel , Ramaswamy V. , Oppenheimer Michael
Published: February 2007

Biomass burning is a major source of air pollutants, some of which are also climate forcing agents. We investigate the sensitivity of direct radiative forcing due to tropospheric ozone and aerosols (carbonaceous and sulfate) to a marginal reduction in their (or their precursor) emissions from major biomass burning regions. We find that the largest negative global forcing is for 10% emission reductions in tropical regions, including Africa (−4.1 mWm−2from gas and −4.1 mWm−2from aerosols), and South America (−3.0 mWm−2from gas and −2.8 mWm−2from aerosols). We estimate that a unit reduction in the amount of biomass burned in India produces the largest negative ozone and aerosol forcing. Our analysis indicates that reducing biomass burning emissions causes negative global radiative forcing due to ozone and aerosols; however, regional differences need to be considered when evaluating controls on biomass burning to mitigate global climate change.
Chemical composition observed over the mid‐Atlantic and the detection of pollution signatures far from source regions
Authors: Lewis A. C. , Evans M. J. , Methven J. , Watson N. , Lee J. D. , Hopkins J. R. , Purvis R. M. , Arnold S. R. , McQuaid J. B. , Whalley L. K. , Pilling M. J. , Heard D. E. , Monks P. S. , Parker A. E. , Reeves C. E. , Oram D. E. , Mills G. , Bandy B. J. , Stewart D. , Coe H. , Williams P. , Crosier J.
Published: February 2007

The atmospheric composition of the central North Atlantic region has been sampled using the FAAM BAe146 instrumented aircraft during the Intercontinental Transport of Ozone and Precursors (ITOP) campaign, part of the wider International Consortium for Atmospheric Research on Transport and Transformation (ICARTT). This paper presents an overview of the ITOP campaign. Between late July and early August 2004, twelve flights comprising 72 hours of measurement were made in a region from approximately 20 to 40°W and 33 to 47°N centered on Faial Island, Azores, ranging in altitude from 50 to 9000 m. The vertical profiles of O3 and CO are consistent with previous observations made in this region during 1997 and our knowledge of the seasonal cycles within the region. A cluster analysis technique is used to partition the data set into air mass types with distinct chemical signatures. Six clusters provide a suitable balance between cluster generality and specificity. The clusters are labeled as biomass burning, low level outflow, upper level outflow, moist lower troposphere, marine and upper troposphere. During this summer, boreal forest fire emissions from Alaska and northern Canada were found to provide a major perturbation of tropospheric composition in CO, PAN, organic compounds and aerosol. Anthropogenic influenced air from the continental boundary layer of the USA was clearly observed running above the marine boundary layer right across the mid‐Atlantic, retaining high pollution levels in VOCs and sulfate aerosol. Upper level outflow events were found to have far lower sulfate aerosol, resulting from washout on ascent, but much higher PAN associated with the colder temperatures. Lagrangian links with flights of other aircraft over the USA and Europe show that such signatures are maintained many days downwind of emission regions. Some other features of the data set are highlighted, including the strong perturbations to many VOCs and OVOCs in this remote region.
Deriving daily carbon fluxes from hourly CO2 mixing ratios measured on the WLEF tall tower: An upscaling methodology
Authors: Chen Jing M. , Chen Baozhang , Tans Pieter
Published: February 2007

The temporal variation of the CO2 mixing ratio in the atmosphere at a given height results from several processes, including photosynthesis and respiration of the underlying ecosystems, the vertical mixing of the atmosphere near the surface and in the planetary boundary layer (PBL), and entrainment of the air above the PBL. Theoretically, if all atmospheric processes are modeled accurately, we can estimate the magnitude of ecosystem photosynthesis and respiration from the variations in the measured CO2 mixing ratio. Through analyzing the CO2 concentration measured at several heights (30 m, 122 m, and 396 m) on the Wisconsin tall tower, we demonstrate that it is possible to derive the daily carbon flux resulting from CO2 uptake from hourly CO2 mixing ratio data. At 30 m, the concentration‐derived daily gross primary productivity (GPP) is well correlated with measured daily GPP derived from flux measurements (r2 = 0.70), but the former was 20% larger than the latter. The correlation increased considerably for 10‐day averages (r2 = 0.87). As the variations at lower heights have larger diurnal CO2 amplitudes, the concentration‐derived GPP is more accurate at lower heights. The footprint distance of CO2 concentration during the daytime under the influence of the mixed layer is estimated to be of the order of 103 km, or a footprint area of 103–104 km2, which is much larger than that of CO2 fluxes measured using eddy covariance methods (typically 1 km2). The difference in these footprint areas may partly explain the differences between these two flux estimates at the Wisconsin tower. These differences also signify the importance of retrieving flux information from the mixing ratio as it provides a means to upscale from local sites to a region.
Hyperglycemia during Ischemia Rapidly Accelerates Brain Damage in Stroke Patients Treated with tPA
Authors: Ribo Marc , Molina Carlos A , Delgado Pilar , Rubiera Marta , Delgado-Mederos Raquel , Rovira Alex , Munuera Josep , Alvarez-Sabin Jose
Published: February 2007

To evaluate impact of glucose burden on diffusion-weighted imaging (DWI)-lesion evolution according to ischemia duration in stroke. We studied 47 patients with transcranial Doppler (TCD)-documented artery occlusion treated with intravenous tissue plasminogen activator. Hyperglycemia (HG) was defined as glucose > 140 mg/dL. A subcutaneous device continuously monitored glucose during 24 h. Magnetic resonance imaging was performed pretreatment (1) and at 24 to 36 h (2) in 30 patients. We measured initial PWI lesion (PW1) and DWI growth: DW2–DW1 (DWg). Serial TCD during 24 h determined occlusion time (OT). National Institutes of Health Stroke Scale (NIHSS) scores were obtained at baseline and 48 h. Poor short-term clinical course defined as <50% recovery of initial NIHSS. Baseline NIHSS was 18. On admission 10 patients (21.3%) were hyperglycemic and presented similar NIHSS, DW1, and PW1 lesion extension as those without HG. During monitoring 24 patients (51%) had HG, 21 (45%) of them during OT (median OT 12 h). Median 48 h-NIHSS was 10; 15 patients presented poor outcome. 48 h-NIHSS was higher in patients with HG during OT (15 versus 3; P < 0.001). Patients with favorable outcome had shorter OT (8.4 versus 17.4 h; P < 0.001). However, the only independent predictor of poor outcome was HG during OT (OR: 20.3; 95% CI: 3.77 to 108.8; P < 0.001). At 24 h mean DWg was 52 cm3. A receiver operating characteristic curve identified DWg > 14 cm3 best predictor of poor outcome (sensitivity, 85.7%; specificity, 75%). Total OT ( P = 0.007) and HG during OT ( P = 0.01) showed the strongest correlation with DWg. DWI lesion grew 2.7 times faster in patients with HG than without HG during OT (1.73 versus 4.63 cm3/h of occlusion; P = 0.07). In a regression model the only independent predictor of DWg was HG during OT (OR: 10.83; 95% CI: 1.96 to 59.83; P = 0.006). Hyperglycemia, especially during OT, has a powerful deleterious effect after stroke accelerating brain damage.
Consequences of nonstochiometric SiOx interfacial layers on the electrical characterization of metal-oxide-semiconductor devices
Authors: de Sousa J. S. , Leite P. F. R. , de Oliveira E. L. , Freire V. N. , Farias G. A.
Published: February 2007

We present a theoretical study of the role of nonstochiometric SiOx suboxides in the oxide-semiconductor interface of Si∕SiO2 metal-oxide-semiconductor (MOS) devices. We show that nonabrupt SiOx layers and fluctuations in their localization imply: (i) Capacitance degradation for voltages above threshold, (ii) variations in the threshold voltage of the order of 20 mV, and (iii) errors in the determination of the effective oxide thickness by means of electrical measurements.
Mechanism of metal-semiconductor transition in electric properties of single-walled carbon nanotubes induced by low-energy electron irradiation
Authors: Kanzaki Kenichi , Suzuki Satoru , Inokawa Hiroshi , Ono Yukinori , Vijayaraghavan Aravind , Kobayashi Yoshihiro
Published: February 2007

Low-energy electron irradiation causes damage in single-walled carbon nanotubes and changes the electric behavior of a nanotube field-effect transistor from metallic to semiconducting at low temperature. The irradiation damage was found to form an energy barrier of several 10meV in the nanotube channel. We show that the transition behavior can be reasonably explained by the barrier formation and gate-induced band bending.
Grain boundary void growth in bamboo interconnect under thermal residual stress field
Authors: Chen N. , Li Z. , Wang H. , Sun J.
Published: February 2007

An analytic expression is developed to predict grain boundary void growth in bamboo interconnect under thermal residual stress field. The rate process is controlled by grain boundary and interconnect/passivation interface diffusions. The thermal residual stress field relaxes during void growth. Based on the present analysis, the behaviors of the void growth and the stress redistribution are characterized as a function of the microstructure of the interconnect, the state of the thermal residual stress, the initial size of the void, as well as the diffusivity ratio between the interface and the grain boundary.
Activation energies in diamond films evaluated using admittance spectroscopy and resistivity measurements
Authors: Chiquito Adenilson J. , Berengue Olívia M. , Diagonel Edgar , Galzerani José C. , Moro João R.
Published: February 2007

This article reports on the study of high-quality boron-doped diamond films using admittance techniques. We have found two well-defined energy states at 74 and 340 meV, indicating that the doping procedure has induced defects and consequently provoked the localization of carriers. This is a direct indication that there are different coexisting conduction mechanisms for the transport of carriers. Additionally, we perform complementary resistivity experiments showing the presence of the variable range hopping as the dominant transport mechanism.
Intercomparison between FI-CL and ICP-MS for the determination of dissolved iron in Atlantic seawater
Authors: Bowie Andrew R. , Ussher Simon J. , Landing William M. , Worsfold Paul J.
Published: February 2007

Environmental context. Iron is arguably the most important trace element for the growth of marine organisms and is the limiting micronutrient for primary production in many parts of the world’s oceans. The concentration of dissolved iron in seawater therefore influences the global carbon cycle and consequently Earth’s climate. Hence, it is important to understand the marine biogeochemistry of iron and quantify its spatial and temporal distribution. In order to achieve this objective, it is essential that reported open-ocean concentrations of dissolved iron are accurate.
Abstract. Results from a 3-laboratory blind intercomparison exercise with two widely used analytical methods for the determination of iron in seawater are presented. The two methods used are coprecipitation followed by isotope dilution inductively coupled plasma mass spectrometry (ICP-MS) and chemical reduction to iron(ii) followed by flow injection with chemiluminescence detection (FI-CL). The five samples used were collected from the South Atlantic Ocean as part of the IRONAGES intercomparison exercise. To avoid any inter-bottle variability, the same sample bottles were sent sequentially to three laboratories in England, Australia and the United States over a 12-month period. The results show that there is no statistical difference (P = 0.05) between the shipboard FI-CL method and the directly traceable, low blank, isotope dilution ICP-MS method for the determination of iron in surface South Atlantic seawater. There was also excellent agreement between the overall mean of the three laboratories (0.54 ± 0.03 nM) and the consensus value from an earlier community-wide separate bottle intercomparison using the same IRONAGES sample water (0.59 ± 0.21 nM).
Arsenic accumulation and speciation in freshwater fish living in arsenic-contaminated waters
Authors: Jankong Patcharin , Chalhoub Cherif , Kienzl Norbert , Goessler Walter , Francesconi Kevin A. , Visoottiviseth Pornsawan
Published: February 2007

Environmental context. Inorganic arsenic, a well-known human carcinogen, represents a major worldwide environmental problem because contaminated water supplies have lead to widespread human exposure. This study investigates the arsenic content of freshwater fish from arsenic-contaminated and non-contaminated sites in Thailand, and reports high arsenic concentrations and significant amounts of inorganic arsenic in the edible muscle tissue. The data suggest that freshwater fish may represent a significant source of inorganic arsenic to some human populations.
Abstract. Striped snakehead (Channa striata), carnivorous freshwater fish that serve as popular food in Thailand, were collected from a reference site (1.4 µg As L–1) and from two arsenic-contaminated ponds (Pond A, 550 µg As L–1; Pond B, 990 µg As L–1) in southern Thailand and analysed for arsenic by inductively coupled plasma mass spectrometry (ICPMS) and for arsenic species by HPLC-ICPMS performed on aqueous methanol extracts of muscle, liver and gill (n = 3 fish from each site). Mean total arsenic concentration in muscle tissue of C. striata collected from the reference site was 1.9 µg As g–1 (dry mass) while fish from the contaminated sites contained 13.1 µg As g–1 (Pond A) and 22.2 µg As g–1 (Pond B). Liver and gill tissues showed similar increasing arsenic concentrations on going from the reference site to Ponds A and B, with Pond B showing the highest levels. Speciation analysis on the three tissues showed that, although arsenate was the major extractable arsenical in reference fish (e.g. 0.73 µg As g–1 in muscle tissue), dimethylarsinate was by far the dominant arsenic species in fish from the two contaminated sites. Three non-carnivorous fish species (Danio regina, Rasbora heteromorpha and Puntius orphoides), collected from Pond B only, had lower arsenic concentrations (7.9–11.3 µg As g–1 in muscle tissue) than did C. striata, and contained appreciable amounts of trimethylarsine oxide together with two other major arsenicals, arsenate and dimethylarsinate, and smaller quantities of arsenite and methylarsonate. The study shows for the first time a clear effect of water arsenic concentrations on natural fish tissue arsenic concentrations, and is the first report of a freshwater fish species attaining arsenic concentrations comparable with those found in marine fish species. Furthermore, the high concentrations of toxic inorganic arsenic (predominantly arsenate) in the muscle tissue of the edible fish C. striata have human health implications and warrant wider investigations.
Long-term effects of different land use and soil management on various organic carbon fractions in an Inceptisol of subtropical India
Authors: Purakayastha T. J. , Chhonkar P. K. , Bhadraray S. , Patra A. K. , Verma V. , Khan M. A.
Published: February 2007

Land use changes, especially the conversion of native forest vegetation to cropland and plantations in tropical regions, can potentially alter soil C dynamics. A study was conducted to assess the effects of various land uses and soil managements (agro-forestry plantation, vegetable field, tube-well irrigated rice–wheat, sewage-irrigated rice–wheat, and uncultivated soils) on soil pH, bulk density, soil organic C (SOC), particulate organic C (POC), microbial biomass C (MBC), C mineralisation (Cmin), microbial quotient, and microbial metabolic quotient (qCO2) in 0−0.05, 0.05−0.10, and 0.10−0.20 m soil depths. At 0−0.05 m, the bulk density was lowest (1.29 Mg/m3) in agro-forestry soil, whereas the uncultivated soil (jointly with vegetable field soil) showed highest bulk density (1.48 Mg/m3). Sewage-irrigated rice–wheat soil showed lowest pH particularly in the 0−0.05 and 0.10−0.20 m soil layer. Irrespective of soil depths, agro-forestry plantation showed greater SOC followed by sewage-irrigated rice–wheat soil. Nevertheless, agro-forestry soil also showed highest stock of SOC (33.7 Mg/ha), POC (3.58 Mg/ha), and MBC (0.81 Mg/ha) in the 0−0.20 m soil layer. Sewage-irrigated rice–wheat jointly with agro-forestry soil showed greatest Cmin in the 0−0.20 m soil layer, although the former supported lower SOC stock. The decrease in SOC (SOC0−0.05 m/SOC0.10−0.20 m) and Cmin (Cmin 0−0.05 m/Cmin 0.10−0.20 m) along soil depth was significantly higher in the agro-forestry system than in most of the other land use and soil management systems. Microbial quotient was highest in sewage-irrigated rice–wheat soil, particularly in the 0−0.05 m soil depth, whereas qCO2 was greater in uncultivated soil. In general, microbial quotients decreased, whereas qCO2 increased down the soil profile.
Metal to metal multiple bonds in ordered assemblies
Authors: Chisholm Malcolm H.
Published: February 2007

The synthesis and properties of metal–metal (MM) quadruply bonded compounds of molybdenum and tungsten in liquid crystalline phases are described. Covalently linked MM quadruply bonded complexes, dimers of dimers, are shown to give rise to mixed valence complexes upon oxidation and the degree of electron delocalization is shown to be correlated with the M
2
δ bridge π interactions. Class III behavior or complete delocalization is observed to M
2
to M
2
distances of up to 14 Å. When the M
2
unit is attached to oligothiophenes via a carboxylate tether, the photophysical properties of the thienyl units are greatly modified due to M
2
δ–thienyl π conjugation and spin–orbit coupling. This leads to long-lived emissive states and electroluminescence in solid-state devices.