bluuebunny/crossref_metadata_2025 huggingface dataset:
Purification of Stearidonic Acid from Modified Soybean Oil by Argentation Silica Gel Column Chromatography
Authors: Kleiner‐Shuhler Leslie , Vázquez Luis , Akoh Casimir C.
Published: March 2011

The objective of this study was to purify stearidonic acid (SDA, 18:4 ω‐3) from modified soybean oil containing a mixture of over 20 fatty acids (23% SDA). Interest in obtaining purified fractions of SDA arises from reported health benefits associated with polyunsaturated fatty acids (PUFA), such as cardiovascular disease prevention. In addition, SDA may also provide improved stability characteristics since its unsaturation index is less than longer PUFA, such as eicosapentaenoic acid (EPA, 20:5 ω‐3). First, a chemical ethanolysis of modified soybean oil was performed to transform the triacylglycerols into fatty acid ethyl esters (FAEE). Then, the FAEE were fractionated and SDA‐EE was purified by argentation silica gel (10% AgNO3) open column chromatography, which allows selectivity based on degree of unsaturation. Different FAEE sample loads and mobile phases were explored until the best purification of SDA‐EE was achieved. The solvents used were hexane and hexane:acetone mixtures (99 and 95%). Under the optimal conditions, a fraction with high SDA‐EE purity (96%) was obtained with 77% yield. Besides, it was possible to obtain another fraction enriched in α‐linolenic acid‐EE (37% purity and 68% yield) and γ‐linolenic acid‐EE (22% purity and 61% yield). A scaled‐up process resulted in 840 mg of final product composed of 97% SDA‐EE with 71% yield.
Parties, Pivots, and Policy: The Status Quo Test
Authors: RICHMAN JESSE
Published: March 2011

Identifying policy status quo locations is a precondition for testing key predictions of many spatial models of legislative politics, but such measures have proved to be extremely difficult to construct. This study applies a novel technique that measures policy locations in relation to legislators’ preferences. The resulting status quo estimates allow for a direct test of the policy consequences predicted by pivotal politics and party cartel theories of legislative politics. The empirical tests indicate that parties interact with pivotal politics to contribute to policy gridlock and shape policy change. By bringing pressure to bear on pivotal politics “pivots” and by blocking policy changes that would “roll” the party, parties increase the range of policies subject to gridlock in the American political system.
‘I TOLD HIM I WAS LENNOX NJOKWENI’: HONOR AND RACIAL ETIQUETTE IN SOUTHERN RHODESIA
Authors: SHUTT ALLISON K.
Published: March 2011

This article focuses on a single episode of racial interaction in 1931 in order to highlight competing notions of honor and respectability in a shared colonial society. This story elucidates how Africans and whites unraveled and rebuilt ‘racial etiquette’, the tacit code that guided individual encounters between blacks and whites and that were so vital to the expression of colonial power. In moments of transition, such as the early 1930s in Southern Rhodesia, the minutiae of racial etiquette were confusing, and this allowed for some dialogue between Africans and whites about what constituted proper behavior. As this story makes clear, Africans were as much a part of composing racial etiquette as whites, despite – indeed, because of – the latter's political power.
TRADERS, SAINTS, AND IRRIGATION: REFLECTIONS ON SAHARAN CONNECTIVITY
Authors: SCHEELE JUDITH
Published: March 2011

Studies of trans-Saharan trade have recently been revitalized, mainly through an exploration of local archives. These archives offer a further possibility: to investigate the link between local settlement and wider patterns of exchange. Material from southern Algeria and northern Mali suggests that oases were not viable without outside investment, that pastoral economies needed storage space and agricultural produce, and that intra-Saharan and trans-Saharan trade relied on each other. Hence, regional mobility and outside connections were not subsidiary but constitutive of the local, and local patterns of production and trans-Saharan commerce were aspects of the same system.
Direct numerical simulation of hypersonic turbulent boundary layers. Part 3. Effect of Mach number
Authors: DUAN L. , BEEKMAN I. , MARTÍN M. P.
Published: March 2011

In this paper, we perform direct numerical simulations (DNS) of turbulent boundary layers with nominal free-stream Mach number ranging from 0.3 to 12. The main objective is to assess the scalings with respect to the mean and turbulence behaviours as well as the possible breakdown of the weak compressibility hypothesis for turbulent boundary layers at high Mach numbers (M > 5). We find that many of the scaling relations, such as the van Driest transformation for mean velocity, Walz's relation, Morkovin's scaling and the strong Reynolds analogy, which are derived based on the weak compressibility hypothesis, remain valid for the range of free-stream Mach numbers considered. The explicit dilatation terms such as pressure dilatation and dilatational dissipation remain small for the present Mach number range, and the pressure–strain correlation and the anisotropy of the Reynolds stress tensor are insensitive to the free-stream Mach number. The possible effects of intrinsic compressibility are reflected by the increase in the fluctuations of thermodynamic quantities (p′rms/pw, ρ′rms/ρ, T′rms/T) and turbulence Mach numbers (Mt, M′rms), the existence of shocklets, the modification of turbulence structures (near-wall streaks and large-scale motions) and the variation in the onset of intermittency.
Empirical treatment with pantoprazole as a diagnostic tool for symptomatic adult laryngopharyngeal reflux
Authors: Masaany M , Marina M B , Sharifa Ezat W P , Sani A
Published: March 2011

Objective:

To determine the sensitivity and specificity of intensive empirical treatment with pantoprazole in diagnosing laryngopharyngeal reflux in adults.

Study design:

This was a prospective, double-blind study.

Subjects and methods:

Fifty-five patients with either a Reflux Symptom Index of more than 13 or a Reflux Finding Score of more than 7 were enrolled. All patients underwent 24-hour, double-probe pH monitoring before commencing pantoprazole 40 mg twice daily; both investigators and patients were blinded to pH monitoring results. The Reflux Symptom Index and Reflux Finding Score were reassessed during the second, third and fourth month of follow up.

Results:

The sensitivity of empirical pantoprazole treatment in diagnosing laryngopharyngeal reflux was 92.5 per cent. The specificity was 14.2 per cent, the positive predictive value 86 per cent and the negative predictive value 25 per cent. There was significant reduction in the total Reflux Symptom Index and Reflux Finding Score after the second, third and fourth month of treatment. There was no correlation between laryngopharyngeal reflux and body mass index.

Conclusion:

Our results suggest that intensive empirical treatment with proton pump inhibitors is effective in diagnosing laryngopharyngeal reflux.
Venous haemangioma of the mandibular division of the trigeminal nerve
Authors: McMonagle B , Connor S , Gleeson M
Published: March 2011

Objectives:

To present a rare cause of facial pain, and the differential diagnosis of a lesion of the mandibular division of the trigeminal nerve.

Case report:

A 19-year-old woman presented to a tertiary referral skull base centre with right periorbital pain and a progressive, right-sided deficit of the mandibular division of the trigeminal nerve. Clinical examination revealed right-sided hypoaesthesia in the mandibular division of the trigeminal nerve dermatome, mild trismus and some wasting of the right masseter muscle. Computed tomography and magnetic resonance imaging scans revealed a small area of mildly enhancing soft tissue centred within the foramen ovale, with concentric enlargement. Surgery was undertaken via an infratemporal fossa (Fisch) type D approach. A vascular lesion was found filling the foramen ovale, with no obvious nerve separate from the lesion. The lesion was removed en bloc. Histopathological analysis demonstrated a venous haemangioma within the nerve.

Conclusion:

Facial pain is common, and may be wrongly attributed to trigeminal neuralgia. A thorough clinical examination must be performed to identify subtle neurological abnormalities, and appropriate imaging undertaken to exclude rare causes, such as this venous haemangioma of the mandibular division of the trigeminal nerve.
Efficacy of endonasal dacryocystorhinostomy, using ‘cold steel’ instruments without stenting, in treatment of distal nasolacrimal duct obstruction
Authors: Ananth L , Hosamani P , Chary G
Published: March 2011

Objective:

To assess the efficacy of an endonasal dacryocystorhinostomy technique using conventional instruments, without the use of any adjunctive techniques.

Study design:

Prospective, non-randomised, cohort study.

Methods:

Patients diagnosed with nasolacrimal duct obstruction between January 2006 and December 2008 were included in the study. Seventy-eight endonasal dacryocystorhinostomies (primary or revision) were performed with conventional ‘cold steel’ instruments. The technique involved complete exposure and marsupialisation of the lacrimal sac. No adjunctive procedures were used. Success was defined as complete resolution of epiphora and a patent lacrimal system, evaluated by lacrimal irrigation and endoscopy, one year post-operatively.

Results:

Seventy-four of the 78 cases were symptom-free after a minimum follow up of 12 months, giving an overall success rate of 94.9 per cent. The success rates for primary and revision cases were 95.5 and 90.9 per cent, respectively.

Conclusion:

Meticulous surgical technique can ensure high success rates with the use of conventional cold steel instruments, without the use of adjunctive procedures, making endonasal dacryocystorhinostomy a cost-effective, reliable procedure.
Nonlinear wavy phenomena into plasma: some cases of stabilization and control of chaotic behaviors
Authors: XAPLANTERIS CONSTANTINE L. , FILIPPAKI ELENI
Published: March 2011

Stabilities, instabilities and turbulences have always appeared into a cylindrical magnetized argon plasma. These phenomena are caused by linear or nonlinear dynamics and are interpreted with the linear or nonlinear theory accordingly. In this paper, an experimental study accompanied by theoretical justification and based on the wave–wave interaction has been made; an azimuthally moved driving wave is enforced in a very simple way. The turbulence stabilization, the wave coupling, the instability synchronization and other wavy interactions, which are caused by using an external spatiotemporal electric signal, are presented. The research of the wavy subjects continuing in our laboratory aspires to comprehend the plasma chaotic behavior and take a step into suppressing the unstable inclination.
Religious actors as epistemic communities in conflict transformation: the cases of South Africa and Northern Ireland
Authors: AHU SANDAL NUKHET
Published: March 2011

With the increasing influence of theocrats and other religious actors on policymakers and masses, recognising the agency of the clergy is crucial. This article uses the ‘epistemic communities’ framework to place the religious ‘agents’ in contemporary politics and it shows how hermeneutics can be treated as a form of ‘episteme’. Until recently, this framework has been used to explain how scientific communities affect policymaking. Using the cases of South Africa and Northern Ireland, this article claims that religious actors, especially with their shared set of normative and principled beliefs as well as shared norms of validity, also meet the requirements of the epistemic community category. The employment of this established IR framework in theorising religious politics has the potential to shed light not only on peacebuilding and mediation, but also violent movements and terrorist organisations that use religion as justification.
Unintentional Falls in Older Adults: A Methodological Historical Review
Authors: Speechley Mark
Published: March 2011

PubMed fournit plus de 6,000 références (700 critiques) sur les chutes accidentelles des personnes âgées. Cet article retrace les jalons principaux et méthodologiques dans l’application de méthodes épidémiologiques depuis les premières publications dans ce domaine, à la fin des années quarante. Dans le contexte des avances faites en définition des cas médicaux, échantillonnage, mesure, conception de la recherche et l’analyse statistique, l’article passe en revue les estimations de fréquence d’apparition, les associations de facteurs de risque, les conséquences de la morbidité et de la mortalité, la démonstration de la théorie des facteurs multirisques à l’aide des interventions sur la prévention des chutes et les défis de modèles de prédiction des risques de chutes. Les explications méthodologiques sont fournies pour les hétérogénéités observées et le cas médical est présenté en faveur d’aller au-delà des listes indifférenciées des facteurs de risque, en mettant l’accent sur l’équilibre et la démarche comme les facteurs par lesquels on peut mieux comprendre les effets mécanistes des facteurs de risque distaux. En outre, l’affaire est faite pour faire avancer nos analyses statistiques en examinant les interactions parmi les facteurs de risque intrinsèques et entre les facteurs intrinsèques, extrinsèques et environnementaux.
Socioeconomic Status and Chemotherapy Use for Melanoma in Older People
Authors: Reyes-Ortiz Carlos A. , Goodwin James S. , Zhang Dong D. , Freeman Jean L.
Published: March 2011

L’objectif de cette étude était d’examiner l’association entre la zone de statut socio-économique (SSE) et recevant une chimiothérapie chez les personnes âgées atteints de mélanome cutané. Une base de données liée à SEER-Medicare (1.329 hommes et femmes blancs âgés de ≥ 66, avec des étapes de mélanome invasif [régionaux et éloignés]; 1991-1999) a été utilisé. SSE a été mesurée par le niveau de pauvreté des secteurs de recensement (moyenne de 1990 et 2000 des données du recensement). Covariables ont été données sociodémographiques, caractéristiques de la tumeur et l’indice de comorbidité. Résidant dans les régions les plus pauvres SES a été associée à une faible probabilité de recevoir une chimiothérapie chez les patients de l’échantillon global (odds ratios ajustés = ou 0,97, intervalle de confiance IC 95% = 0.95 à 0.99), et ceux au stade régional au moment du diagnostic (OR 0,97, IC à 95% de 0.94 à 0.98). Ces résultats reflètent les disparités socio-économiques dans l’utilisation de chimiothérapie pour le mélanome chez les patients âgés blancs aux Etats-Unis.
Continuous dependence on elastic moduli in the motion of a semi-infinite elastic cylinder
Authors: KNOPS R. J. , QUINTANILLA R.
Published: March 2011

Continuous dependence upon the elastic moduli of the total energy, and consequently in appropriate measure of the stress, strain and displacement, is established in the initial boundary value problem defined on a semi-infinite cylinder occupied by a linear anisotropic compressible elastic material. Free, constrained and mixed boundary conditions on the lateral surface of the cylinder are discussed. The conclusions are obtained using differential inequalities and partly depend upon previously published results.
Human lifespan: what determines the intrinsic length of human lives?
Authors: Crosse David JM
Published: March 2011

Humans have an intrinsic lifespan of approximately 120 years. Classic evolutionary theories of ageing explain the limit as a response to inevitable cellular damage. The theories share the notion that natural selection acts less strongly to purge deleterious genes that are expressed after reproduction. Reproduction schedules are influenced by a species' ecology and so it is ecological factors which explain interspecies variation in lifespan. Human ecology has favoured the selection of an unusually large brain that both confers advantages that promote longevity and requires longevity to make it a worthwhile investment. The relatively long human lifespan therefore co-evolved with the large human brain.
Anomalous origin of the right coronary artery from the pulmonary artery associated with tetralogy of Fallot: description of the pre-surgical diagnosis and surgical repair
Authors: Pluchinotta Francesca R. , Vida Vladimiro , Milanesi Ornella
Published: March 2011

Anomalous origin of the right coronary artery from the pulmonary artery is a rare congenital defect. We describe the case of an infant with anomalous origin of the right coronary artery from the pulmonary artery in association with tetralogy of Fallot. This patient had a pre-operative echocardiographic diagnosis, which was confirmed by angiography, and later underwent a successful surgical repair.
Cerebral Volume Loss, Cognitive Deficit, and Neuropsychological Performance: Comparative Measures of Brain Atrophy: II. Traumatic Brain Injury
Authors: Tate David F. , Khedraki Rola , Neeley E. Shannon , Ryser David K. , Bigler Erin D.
Published: March 2011

Traumatic brain injury (TBI) results in a variable degree of cerebral atrophy that is not always related to cognitive measures across studies. However, the use of different methods for examining atrophy may be a reason why differences exist. The purpose of this manuscript was to examine the predictive utility of seven magnetic resonance imaging (MRI) -derived brain volume or indices of atrophy for a large cohort of TBI patients (n= 65). The seven quantitative MRI (qMRI) measures included uncorrected whole brain volume, brain volume corrected by total intracranial volume, brain volume corrected by the ratio of the individual TICV by group TICV, a ventricle to brain ratio, total ventricular volume, ventricular volume corrected by TICV, and a direct measure of parenchymal volume loss. Results demonstrated that the various qMRI measures were highly interrelated and that corrected measures proved to be the most robust measures related to neuropsychological performance. Similar to an earlier study that examined cerebral atrophy in aging and dementia, these results suggest that a single corrected brain volume measure is all that is necessary in studies examining global MRI indicators of cerebral atrophy in relationship to cognitive function making additional measures of global atrophy redundant and unnecessary. (JINS, 2011,17, 308–316)
A behavioural intervention incorporating specific glycaemic index goals improves dietary quality, weight control and glycaemic control in adults with type 2 diabetes
Authors: Miller Carla K , Headings Amy , Peyrot Mark , Nagaraja Haikady
Published: March 2011

Objective

A lower glycaemic index (GI) diet is associated with a reduction in glycosylated Hb (HbA1c) in people with diabetes. Yet, little research has been conducted to determine the effects of specific goals regarding consumption of low GI (LGI) foods on diabetes outcomes. The present study evaluated a behavioural intervention on dietary intake, weight status and HbA1c, which included a goal to consume either six or eight servings of LGI foods daily.

Design

A parallel two-group design was used. Following the 5-week intervention, participants were randomly assigned to the group of six (n 15) or eight (n 20) servings of LGI foods daily and followed up for 8 weeks. Dietary intake was assessed using the mean of 4 d food records.

Setting

A metropolitan community in the USA.

Subjects

Individuals aged 40–65 years with type 2 diabetes of ≥1 year and HbA1c ≥ 7·0 % were eligible.

Results

There was no significant difference between goal difficulty groups with regard to GI servings at the end of the study. However, mean consumption of LGI foods increased by 2·05 (se 0·47) and 1·65 (se 0·40) servings per 4184 kJ in the six (P < 0·001) and eight (P < 0·001) LGI serving groups, respectively. For all participants combined, there were significant decreases in mean HbA1c (−0·58 (se 0·21) %; P = 0·01), weight (−2·30 (se 0·78) kg; P = 0·01), BMI (−0·80 (se 0·29) kg/m2; P = 0·01) and waist circumference (−2·36 (se 0·81) cm; P = 0·01).

Conclusions

An intervention including a specific goal to consume six to eight servings of LGI foods daily can improve diabetes outcomes. Clinicians should help patients set specific targets for dietary change and identify ways of achieving those goals.
Predictors of adolescent weight status and central obesity in rural South Africa
Authors: Kimani-Murage Elizabeth W , Kahn Kathleen , Pettifor John M , Tollman Stephen M , Klipstein-Grobusch Kerstin , Norris Shane A
Published: March 2011

Objective

To investigate predictors of adolescent obesity in rural South Africa.

Design

Cross-sectional study. Height, weight and waist circumference were measured using standard procedures. Overweight and obesity in adolescents aged 10–17 years were assessed using the International Obesity Taskforce cut-offs, while the WHO adult cut-offs were used for participants aged 18–20 years. Waist-to-height ratio of >0·5 defined central obesity in those at Tanner stages 3–5. Linear and logistic regression analysis was used to evaluate risk factors.

Setting

Agincourt sub-district, rural South Africa.

Subjects

Participants (n1848) were aged 10–20 years.

Results

Combined overweight and obesity was higher in girls (15 %) than boys (4 %), as was central obesity (15 % and 2 %, respectively). With regard to overweight/obesity, fourfold higher odds were observed for girls and twofold higher odds were observed for participants from households with the highest socio-economic status (SES). The odds for overweight/obesity were 40 % lower if the household head had not completed secondary level education. For central obesity, the odds increased 10 % for each unit increase in age; girls had sevenfold higher oddsv. boys; post-pubertal participants had threefold higher oddsv. pubertal participants; those with older mothers aged 50+ years had twofold higher oddsv. those whose mothers were aged 35–49 years; those in highest SES households had twofold higher oddsv. those in lowest SES households.

Conclusions

In rural South Africa, adolescent females are most at risk of obesity which increases with age and appears to be associated with higher SES. To intervene effectively, it is essential to understand how household factors influence food choice, diet and exercise.
Dose-dependent cholesterol-lowering effects of phytosterol/phytostanol-enriched margarine in statin users and statin non-users under free-living conditions
Authors: Eussen Simone RBM , de Jong Nynke , Rompelberg Cathy JM , Garssen Johan , Verschuren WM Monique , Klungel Olaf H
Published: March 2011

Objective

To assess the effectiveness (extent to which an intervention works in daily medical practice) of the use of phytosterol/phytostanol-enriched margarines to lower total and non-HDL cholesterol levels in users and non-users of statins.

Design

Retrospective cohort study.

Setting

Data were obtained from questionnaires on health and food intake from a population-based longitudinal cohort linked to pharmacy-dispensing records.

Subjects

The analysis included 3829 men and women (aged 31–71 years) who were examined during 1998–2002 and re-examined at 5-year follow-up during 2003–2007.

Results

Recommended doses of margarines were consumed by only 9 % of the subjects. Serum total cholesterol decreased by respectively −0·16 (95 % CI −0·26, −0·05) mmol/l, −1·40 (95 % CI −1·51, −1·30) mmol/l and −1·64 (95 % CI −1·91, −1·37) mmol/l in subjects who started to use phytosterols/phytostanols only, statins only or a combination of both compounds at some point in time between examination and re-examination, compared with subjects who did not start using phytosterols/phytostanols or statins. Cholesterol-lowering effects of the phytosterols/phytostanols were similar in statin users and statin non-users and increased with increasing intake of enriched margarine (no intake, 0; low intake, −0·017 (95 % CI −0·16, 0·13) mmol/l; medium intake, −0·089 (95 % CI −0·22, 0·038) mmol/l; high intake, −0·32 (95 % CI −0·50, −0·14) mmol/l).

Conclusions

Although recommended intake levels of the enriched margarines were not reached by all persons, these data show that under customary conditions of use phytosterols/phytostanols are effective in lowering cholesterol levels in both statin users and non-users.
Introduction to a Special Issue on Surface Analysis
Authors: Smentkowski Vincent S.
Published: March 2011

The surface, or topmost layers of a material, is the region that is in contact with the environment. The composition and chemistry of the surface often can be drastically different from that of the bulk. For many materials systems (catalysts, coatings, biomedical devices, etc.), the surface chemistry and/or properties determine the device performance. Adhesion, delamination, staining, and corrosion are among the important surface phenomena that need to be understood in industrial settings. Over the past forty years, a number of surface analysis techniques have been commercialized to characterize the composition and microstructure of the surface. The most commonly used techniques are summarized in this issue of Microscopy Today.
A Database for Peer-Reviewed Microscopy Images and Their Unpublished Brethren
Authors: Kane Caroline , Mitchison Timothy , Goldberg Joan , Orloff David N.
Published: March 2011

With the advent of the computer age and in particular, the Internet, information sources have multiplied. However, the need for information verification has never been greater. In a day when anyone can easily produce a website, blog, or tweet, you can't believe what you read or see just because it's “published.” Scientific data and analysis require peer review, and peer-reviewed data need a home. Equally important, for every piece of data in a peer-reviewed publication, there are usually many pieces that provided essential support for the conclusions of the study but could not be included due to space limitations. This is especially true of image data, which are necessarily gigabyte-hungry.
Time-of-Flight Secondary Ion Mass Spectrometry
Authors: Schnieders Albert
Published: March 2011

The properties of many modern products are not only governed by their surface morphology and structure but also by their surface chemistry. For example, in some cases a contamination of less than a monolayer of molecules can be responsible for the failure of a coating with all its consequences (aesthetics, protection, life time, and so on). Other areas affected by surface chemistry are adhesion, staining, corrosion, and so on. Thus, powerful analytical techniques for the identification, as well as the localization and quantification, of substances on a surface or at the interface between different layers are of increasing importance for fast and efficient failure analysis. However, surface analysis is not only limited to failure analysis but can be also used in research and development of, for example, methods of surface modification on the molecular level as well as in production and quality control, such as the evaluation of cleaning procedures.
Application of X-ray Photoelectron Spectroscopy (XPS) for the Surface Characterization of Gunshot Residue (GSR)
Authors: Schwoeble A. J. “Skip” , Strohmeier Brian R. , Bunker Kristin L. , McAllister Darlene R. , Marquis James P. , Piasecki John D. , McAllister Nikki M.
Published: March 2011

Gunshot residue (GSR) is typically found on the hands or clothing of persons who have been in the environment of a discharging firearm, but it may also be found on objects in the vicinity of the discharge. Computer-controlled scanning electron microscopy (CCSEM) is the method preferred by the forensic community for the automated analysis of GSR. GSR samples are therefore typically collected from a crime suspect's hands and/or clothing using SEM sample stubs coated with a conductive adhesive. The three major components in modern firearm cartridge primers are lead styphanate (initiator), antimony sulfide (fuel), and barium nitrate (oxidizer). GSR consists of the products of combustion of these primer materials. Large populations of particles in the size range of ~1–10 μm are rapidly screened by energy-dispersive X-ray spectroscopy (EDS) for the presence of combinations of Pb, Sb, and Ba. When combinations of these three elements are detected, the particles are flagged as potential GSR particulate. Flagged particles with significant Pb/Sb/Ba compositions are subsequently relocated for a live identification and a positive confirmation of GSR. Positive particles are classified as being either “characteristic of GSR” (that is, all three key elements are present) or “consistent with GSR” (that is, any two of the key elements are present) based on the particle composition and morphology. Classification is based on the presence of the constituent elements and is not dependant on the element amounts. If a particle does not meet the proper compositional or morphological criteria, it is rejected as GSR. However, CCSEM generally does not provide information regarding the population of particles much less than 1 μm or the surface chemistry of the GSR particles. This article examines the fine fraction of GSR particles with high-resolution electron microscopy and complements the microscopy data with surface chemistry information from X-ray photoelectron spectroscopy (XPS).
Special Issue: Surface Analysis
Authors: Lyman Charles
Published: March 2011

Last November's Microscopy Today was our first special issue to focus on a single microscopy topic (scanning probe microscopy). The present issue on surface analysis is the first to have a guest editor, Vincent Smentkowski. Vincent brought me the idea of a special issue on surface analysis, and I was pleased to help him bring this topic to our readers. Many journals publish highly technical special issues, but that is not the goal here. These articles on surface analysis techniques are aimed at the general microscopist. Each article provides a brief introduction to a technique, discusses the method's capabilities, and gives a few applications.
Element-specific high-resolution diffraction microscopy using focused hard X-ray beam
Authors: Takahashi Y. , Nishino Y. , Tsutsumi R. , Zettsu N. , Yamauchi K. , Ishikawa T. , Matsubara E.
Published: March 2011

We demonstrated high-resolution element-specific diffraction microscopy using a hard X-ray beam focused by Kirkpatrick–Baez mirrors. Coherent diffraction patterns of an Au/Ag nanoparticle were measured at incident X-ray energies around the Au LIII absorption edge. By calculating the difference between the intensities of reconstructed images obtained at different energies, an image of the Au element could be derived. From the difference image, it was suggested that the replacement reaction progresses from the corners of Ag cubic particle.
Valence band of Co/Cu thin film studied with synchrotron radiation photoemission spectroscopy
Authors: Banik Soma , Deb S. K. , Barman S. , Das G. P. , Phase D. M. , Rai S. K.
Published: March 2011

The electronic structure of Co (100 Å)/Cu (50 Å) bilayer film on Si(100) has been investigated using valence band photoemission at 50 eV. The aim is to understand the Co/Cu interface and the nature of intermixing in Co and Cu layers. The valence band of Co/Cu interface shows three features at −0.3, −1.17 and −1.9 eV binding energy. The experimental observations are explained with the help of calculations based on projected augmented wave pseudopotential method using density functional theory. The origin of −0.3 eV feature is mainly due to the Co 3d minority spin states while the features at −1.17 and −1.9 eV are due to the formation of Co and Co–Cu mixed nanoclusters at the interface.
Electronic structure of CeAg2Ge2 studied by resonant and angle-resolved photoemission spectroscopy
Authors: Banik Soma , Deb S. K. , Chakrabarti A. , Thamizhavel A. , Phase D. M. , Jha S. N.
Published: March 2011

The electronic structure of CeAg2Ge2 single crystal has been investigated by using resonant valence band photoemission and angle-resolved photoemission spectroscopy at different photon energies. Resonant photoemission has been observed near the 4d threshold of Ce at 121 eV. The constant initial state spectra show two photoemission features having 4f character near the Fermi level that exhibits Fano-like sharp resonance profile. Experimental energy bands have been mapped from the normal-emission photoelectron spectra of CeAg2Ge2 (001) surface along the Γ–Z direction. Four photoemission features are observed to show the dispersion related to the Ce 4f states and the hybridized Ag 4d with Ge 4p states. The experimental spectra have been interpreted with the help of calculations based on full potential linear augmented plane wave method using density functional theory.
Pränatale Infektion als Risikofaktor altersbedingter neurodegenerativer Erkrankungen
Authors: Knuesel
Published: March 2011

Die Alzheimer-Demenz ist die häufigste Form altersbedingter neuro-degenerativer Erkrankungen. Neben wenigen genetischen sind zahlreiche nicht-genetische Risikofaktoren bekannt, die den Krankheitsbeginn und -verlauf signifikant beeinflussen. Die molekularen Ursachen und kausalen Zusammenhänge sind allerdings weitgehend unbekannt. Wir haben ein Mausmodell etabliert, das mittels pränataler Infektion eine langfristige Dysregulation inflammatorischer Modulatoren verursacht und damit einen zentralen altersassoziierten Faktor moduliert. Diese frühe Immunstimulation hat einen stark beschleunigenden Effekt auf altersbedingte Neuropathologien. Falls zu dieser pränatalen auch noch eine systemische Infektion im Alter kommt, wird dieser Effekt signifikant verstärkt. Diese Daten zeigen, dass eine pränatale Infektion das Risiko einer Demenzerkrankung stark erhöhen und in Kombination mit einer zusätzlichen Immunstimulation im Alter ein kritischer Auslöser einer progressiven Neuropathologie darstellen kann.
Volcanic lightning as a source of reactive radical species in eruption plumes
Authors: Martin R. S. , Ilyinskaya E.
Published: March 2011

Volcanic lightning has accompanied most recent major explosive eruptions and provides a source of intense thermal energy to drive the formation of reactive radical species. These radicals may have an impact upon the chemical evolution of the eruption plume and its interaction with the atmosphere. Equilibrium modeling shows that within each lightning channel >1% of total N, O, and F and ∼100% of H, Cl, Br, and I may remain as radicals after quenching. The production of radicals generally increases with the quenching temperature of the gas mixture and the dilution of the eruption plume and decreases with increasing atmospheric pressure. Despite the small volume fraction of the plume directly exposed to volcanic lightning (i.e., <10−4), the production of O, H, F, and NO is predicted to be quantitatively significant over the entire plume. Furthermore, these radicals may indirectly lead to the production of Br, Cl, HO2, and O3 through reactions occurring at low temperature. We suggest that volcanic lightning may promote the oxidation of magmatic gases (e.g., HBr and SO2) and result in a wide range of atmospheric impacts, including tropospheric ozone depletion, the production of fixed nitrogen species, and the formation of cloud condensation nuclei.
Toward a Theory of Followership
Authors: Popper Micha
Published: March 2011

Unlike most of the leadership literature, which focuses on the leaders themselves, the point of departure in this paper is that the psychology of the followers is the key to understanding the leaders' influence. Followers' attraction to leaders is analyzed from three theoretical perspectives: (a) psychodynamic, according to which the leader represents a protective parental figure; (b) psycho-cognitive, in which the leader serves as a convenient explanation for a complex reality; and (c) social-psychological, in which the leader becomes a kind of narrative that grants meaning and strengthens social identity. The article illustrates how these perspectives can help in the choice of concepts and models of leadership and in examining their validity in predicting and explaining leaders' influence in various contexts.
Supervision: Changes in Standards–Changes in Roles
Authors: Cole Lorena , Backes Lora , Enloe Tanya , Stonestreet Ruth , Gorham-Rowan Mary , Carson Lila
Published: March 2011

The American Speech-Language-Hearing Association (ASHA) revised the standards for the Certificate of Clinical Competence in 2005 (ASHA, 2005). Clinical supervisory faculty have been directly affected in their work with graduate clinicians. Knowledge and skills acquisition now must meet the new certification standards for speech-language pathology. As roles have changed regarding time spent in various duties, a time study (analyzing how supervisors spent their time) was conducted by Valdosta State faculty in 1999. A second study, with more recent data, was initiated to compare to the original study conducted in 1999. This second time study analysis revealed changes in roles and time allotment per roles in one university setting. A comparison of these studies is discussed in this article.
Consumer Literacy and the Readability of Health Education Materials
Authors: Martinez Silvia
Published: March 2011

Written materials about communication sciences and disorders frequently are used for patient intake, prevention, community education, counseling, subject recruitment for research, therapy activities, assessment procedures, and treatment monitoring. In order to increase the effectiveness of print material, one must consider the interactive nature of the reading process between the reader and the written material. Therefore, to increase understandability, settings should consider the reading and cognitive skills of consumers, as well as the surface, deep, and design elements in materials.
Q-difference and confluent forms of the lattice Boussinesq equation and the relevant convergence acceleration algorithms
Authors: Sun Jian-Qing , He Yi , Hu Xing-Biao , Tam Hon-Wah
Published: March 2011

A q-difference lattice Boussinesq equation and its confluent form are proposed. With the help of determinant identity, their molecule solutions are constructed. It is shown that the q-difference lattice Boussinesq equation can be used as a numerical convergence acceleration algorithm to compute the approximation limt → ∞f(t). Numerical examples with the application of this algorithm are presented.
Scattering induced current in a tight-binding band
Authors: Bruneau L. , De Bièvre S. , Pillet C.-A.
Published: March 2011

In the single band tight-binding approximation, we consider the transport properties of an electron subject to a homogeneous static electric field. We show that repeated interactions of the electron with two-level systems in thermal equilibrium suppress the Bloch oscillations and induce a steady current, the statistical properties of which we study.
High-energy monoenergetic protons from multistaged acceleration of thin double-layer target by circularly polarized laser
Authors: Zhang Z. M. , He X. T. , Sheng Z. M. , Yu M. Y.
Published: March 2011

Multistaged acceleration of solid-density thin foils by ultraintense circularly polarized laser pulse is investigated. A stable radiation pressure acceleration (RPA) stage is first established. Higher dimensional effects such as transverse instabilities and enhanced electron heating then gradually make the initially opaque foil transparent to the laser light. Accordingly, the dominant acceleration mechanism changes smoothly from RPA to target normal sheath acceleration (TNSA). The transition can therefore enhance the maximum energy of the accelerated ions but broaden their energy spectrum. For a double-layer target, however, the light ions (protons) in the backlayer can be efficiently accelerated in the RPA and TNSA regimes nearly monoenergetically. Two-dimensional particle-in-cell simulations show that with this scheme a circularly polarized laser pulse of peak intensity 3.9×1022 W/cm2 can produce a collimated proton bunch that persists for many Rayleigh lengths and its peak energy can reach 4.2 GeV with FWHM of 200 MeV.
Micro-nondestructive evaluation of microelectronics using three-dimensional acoustic imaging
Authors: Zhang Guang-Ming , Harvey David M. , Burton David R.
Published: March 2011

Holographic-like three-dimensional (3D) acoustic imaging is developed for micro-nondestructive evaluation of microelectronics. It is implemented by stacking all the interface slices together to locate and identify hidden defects. Matching pursuit based acoustic time-frequency domain imaging is proposed to overcome the wavelength limit of axial resolution so that ultra-thin slices are generated. Experiments are performed on 3D acoustic data collected from microelectronic packages. Results show that the proposed technique resolves closely spaced features that are unavailable by conventional acoustic imaging, revealing more image details of defects.
Communication: A new approach to dual-basis second-order Møller–Plesset calculations
Authors: Deng Jia , Gill Peter M. W.
Published: March 2011

We describe a hierarchy of approximations (MP2[x]) that allow one to estimate second-order Møller–Plesset (MP2) energies in a large basis set from small-basis calculations. The most cost-effective approximation, MP2[K], is significantly cheaper than full MP2 but numerical tests on small atoms and molecules indicate that it is nonetheless accurate. We conclude that MP2[K] is an attractive level of theory for large systems.
Aspect-ratio and lateral-resolution enhancement in force microscopy by attaching nanoclusters generated by an ion cluster source at the end of a silicon tip
Authors: Martínez L. , Tello M. , Díaz M. , Román E. , Garcia R. , Huttel Y.
Published: March 2011

One of the factors that limit the spatial resolution in atomic force microscopy (AFM) is the physical size of the probe. This limitation is particularly severe when the imaged structures are comparable in size to the tip's apex. The resolution in the AFM is usually enhanced by using sharp tips with high aspect ratios. In the present paper we propose an approach to modify AFM tips that consists of depositing nanoclusters on standard silicon tips. We show that the use of those tips leads to atomic force microscopy images of higher aspect ratios and spatial resolution. The present approach has two major properties. It provides higher aspect-ratio images of nanoscale objects and, at the same time, enables to functionalize the AFM tips by depositing nanoparticles with well-controlled chemical composition.
Synthesis and waveguiding of single-crystalline LiNbO3 nanorods
Authors: Huang Jingyun , Chen Zhong , Zhang Zesong , Zhu Chongyu , He Haiping , Ye Zhizhen , Qu Guangyuan , Tong Limin
Published: March 2011

Single-crystalline LiNbO3 nanorods with a trigonal rhombic crystal structure are synthesized through hydrothermal reaction with KOH, LiOH⋅H2O, and Nb2O5 as source materials. LiNbO3 nanorods were along the [110] crystallographic direction. KOH was found to be essential for the formation of one dimensional nanostructures. Meanwhile, waveguiding performance of the LiNbO3 nanorods was investigated. The as-synthesized nanorods exhibit broadband waveguiding capability in the experiments. High temperature annealing was also proved to be effective in enhancing the transmission of the nanowire waveguides by reducing the defects in the nanorods.
Probability of divacancy trap production in silicon diodes exposed to focused ion beam irradiation
Authors: Pastuović Željko , Vittone Ettore , Capan Ivana , Jakšić Milko
Published: March 2011

We present ion beam induced charge (IBIC) measurements of the critical displacement damage dose Dd values and modeling of the probability of divacancy trap production in p+−n−n+ silicon diodes exposed to megaelectron volt energy ion beam irradiation. The normalized induced charge (Q0/Q) measured by He ion probe in tested silicon diodes irradiated by focused He, Li, O, and Cl ion beams with energies of about 0.3 MeV/u increases linearly with Dd according to the modified radiation damage function and nonionizing energy loss (NIEL) theory. A simple IBIC model based on Gunn theorem showed clear dependence of the induced charge Q and corresponding equivalent damage factor Ked value on both a depth profile of charge created by ionizing particle (probe) and a depth distribution of stable defects created from primary defects produced by damaging ions. The average probability of the divacancy production (defined as the ratio of the final electrical active defect quantity and primary ion induced vacancy quantity for each impinging ion) of 0.18 (18%) was calculated by the IBIC modeling for all damaging ions.
Strengthening Causal Inference through Qualitative Analysis of Regression Residuals: Explaining Forest Governance in the Indian Himalaya
Authors: Agrawal Arun , Chhatre Ashwini
Published: March 2011

This paper contributes to fertile debates in environmental social sciences on the uses of and potential synergies between qualitative and quantitative analytical approaches for theory development and validation. Relying on extensive fieldwork on local forest governance in India, and using a dataset on 205 forest commons, we propose a methodological innovation for combining qualitative and quantitative analyses to improve causal inference. Specifically, we demonstrate that qualitative knowledge of cases that are the least well predicted by quantitative modeling can strengthen causal inference by helping check for possible omitted variables, measurement errors, nonlinearities in posited relationships, and possible interaction effects, and thereby lead to analytical improvements in the quantitative analysis. In the process, the paper also presents a contextually informed and theoretically engaged empirical analysis of forest governance in north India, showing in particular the importance of institutional and historical factors in influencing commons outcomes.
Biosecurity, Trade Liberalisation, and the (anti)Politics of Risk Analysis: The Australia-New Zealand Apples Dispute
Authors: Higgins Vaughan , Dibden Jacqui
Published: March 2011

Biosecurity represents a rapidly growing area of social science inquiry. At the global scale, biosecurity measures adopted by national governments have often been represented as nontariff trade barriers, yet social scientists have paid little attention to the ways in which biosecurity concerns are rendered (at least ostensibly) compatible with trade liberalisation. We use Barry's notion of the ‘antipolitical economy’ to explore how techniques used to frame biosecurity risk are linked to the politics of trade liberalisation. Drawing upon a case study of the long-running dispute concerning access by New Zealand apples to the Australian market, we highlight the significance of the import risk-analysis process used by Biosecurity Australia in framing potential outbreaks of fire-blight disease as a technical issue of risk management—an antipolitical activity. This attempt to shift disease-risk concerns away from the political was contested by Australian and New Zealand growers, who variously viewed the risk-assessment process as insufficiently scientific or as protectionist. We conclude that focusing on risk assessment as a political but putatively antipolitical activity provides crucial insights into the nuanced and complex relationship between biosecurity and trade liberalisation.