bluuebunny/crossref_metadata_2025 huggingface dataset:
Wastewaters decontamination: Mechanisms of PB(II), ZN(II), and CD(II) competitive adsorption on tunisian smectite in single and multi‐solute systems
Authors: Eloussaief Mabrouk , Hamza Wiem , Kallel Nejib , Benzina Mourad
Published: February 2012

Polluted water may contain more than one heavy metal species. Consequently, the behavior of a particular metal in a water system may be affected by the presence of the others. In this study, the adsorption of Pb(II), Zn(II), and Cd(II) in single and multi‐element systems onto raw, acid‐activated, and aluminum‐pillared Tunisian smectite (RSM, ASM, and Al‐SM, respectively) was investigated as a function of pH and species concentrations. Physico‐chemical, Textural, XRD, and SEM analyses were investigated onto three different clay materials. The Al‐SM samples, which were calcined at 450°C, presented the best results for the surface areas (267 m2/g) and for the Pb(II) adsorption capacity (75.35 mg/g). For instance, once they contained in a batch system at 25°C, pH 6, they retained more heavy metals due to their textural characteristics. The selected order of adsorption Pb(II) > Zn(II) > Cd(II) showed the importance of the competitive phenomenon onto clay materials' pores adsorption. At a higher pH, the precipitation phenomenon was possible. The two‐site, Langmuir isotherm also yielded the best fit for Pb(II) and Zn(II) adsorption on RSM and Al‐SM in binary and ternary solute‐systems. However, it failed in the case of Pb(II), Zn(II), and Cd(II) on ASM, which had less heterogeneity than other samples. The obtained results can serve as baseline data to design an adsorption process using this local adsorbent for the wastewaters rich in heavy metals. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 229‐238, 2013
Knowledge‐based neural network approaches for modeling and estimating radon concentrations
Authors: Akkala Arjun , Bhatt Deepak , Devabhaktuni Vijay , Kumar Ashok
Published: February 2012

Radon is a chemically inert, tasteless, and odorless gas, which causes lung cancer in people who are exposed to higher concentrations for extended periods of time. It is a byproduct of the decay of uranium in the soil. High concentrations are present in closed units, like houses, schools, etc. To identify houses with unacceptably high radon levels, the radon concentration for each zip code in Ohio needs to be measured. However, not all of the zip codes are surveyed, owing to reasons such as inapproachability. In places where data is unavailable, the concentrations need to be estimated using interpolation techniques. This article proposes the application of knowledge‐based neural network approaches, namely prior knowledge input method, source difference method, and space‐mapped neural network method for modeling and predicting radon concentrations. To this end, knowledge available in the form of uranium concentration data is exploited. Modeling accuracies of the proposed techniques are compared with those of the commonly used multilayer perceptron networks (employed in one of our recent work) and conventional interpolation techniques. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 355‐364, 2013
Inelastic velocity ratio
Authors: Hatzigeorgiou George D. , Papagiannopoulos George A.
Published: February 2012

Knowledge of maximum velocity is essential for the design of structures and especially those with supplementary dampers. Although the nonlinear time history analysis leads to reliable estimation of actual velocities, it seems to be complicated for the everyday engineering practice due to the increased computational cost. This paper proposes an alternative for single‐degree‐of‐freedom (SDOF) systems to estimate the actual velocity in a straightforward and effective manner. More specifically, this study examines the inelastic velocity ratio (IVR), i.e., the ratio of the maximum inelastic to the maximum elastic velocity of an SDOF system, the knowledge of which allows the computation of maximum inelastic velocity directly from the corresponding elastic counterpart. The proposed method is general and can be applied to both conventional structures and structures with supplementary dampers. Extensive parametric studies are conducted to obtain expressions for IVR in terms of the period of vibration, viscous damping ratio, force reduction factor, and soil class. Copyright © 2012 John Wiley & Sons, Ltd.
Personality Changes in Bulimia Nervosa after a Cognitive Behaviour Therapy
Authors: Agüera Zaida , Krug Isabel , Sánchez Isabel , Granero Roser , Penelo Eva , Peñas‐Lledó Eva , Jiménez‐Murcia Susana , Menchón Jose Manuel , Fernández‐Aranda Fernando
Published: February 2012

Objectives

The goals of this study were to evaluate changes in personality traits in outpatients with bulimia nervosa and specific clinical predictors of such personality changes, after cognitive behaviour therapy (CBT).

Method

The sample comprised 100 purging bulimia nervosa outpatients (DSM‐IV‐TR). Assessment measures included the Eating Disorders Inventory‐2, Symptom Check List Revised and Temperament and Character Inventory‐Revised, as well as other clinical and psychopathological indices. All measures were administered before and after 22 weeks of group CBT.

Results

The temperament traits of Harm Avoidance and Reward Dependence and the character traits of Self‐Directedness and Self‐Transcendence changed after CBT. Pre–post CBT reduction in Eating Disorders Inventory‐2 total score predicted the decrease and increase in Harm Avoidance and Self‐Directedness, respectively.

Conclusions

Results suggest that group CBT in outpatient women settings influence changes in some personality traits, which appear mainly related to an overall improvement in eating pathology. Copyright © 2012 John Wiley & Sons, Ltd and Eating Disorders Association.
Activity dynamics and behavioral correlates of CA3 and CA1 hippocampal pyramidal neurons
Authors: Mizuseki Kenji , Royer Sebastien , Diba Kamran , Buzsáki György
Published: February 2012

The CA3 and CA1 pyramidal neurons are the major principal cell types of the hippocampus proper. The strongly recurrent collateral system of CA3 cells and the largely parallel‐organized CA1 neurons suggest that these regions perform distinct computations. However, a comprehensive comparison between CA1 and CA3 pyramidal cells in terms of firing properties, network dynamics, and behavioral correlations is sparse in the intact animal. We performed large‐scale recordings in the dorsal hippocampus of rats to quantify the similarities and differences between CA1 (n > 3,600) and CA3 (n > 2,200) pyramidal cells during sleep and exploration in multiple environments. CA1 and CA3 neurons differed significantly in firing rates, spike burst propensity, spike entrainment by the theta rhythm, and other aspects of spiking dynamics in a brain state‐dependent manner. A smaller proportion of CA3 than CA1 cells displayed prominent place fields, but place fields of CA3 neurons were more compact, more stable, and carried more spatial information per spike than those of CA1 pyramidal cells. Several other features of the two cell types were specific to the testing environment. CA3 neurons showed less pronounced phase precession and a weaker position versus spike‐phase relationship than CA1 cells. Our findings suggest that these distinct activity dynamics of CA1 and CA3 pyramidal cells support their distinct computational roles. © 2012 Wiley Periodicals, Inc.
The Menace of Commercialized Guidance
Authors: DAVIS JESSE B.
Published: February 2012

From exposure of racketeering methods employed by gyp “trainers”1 and “placers”2 Occupations takes up similar problems faced by the public for those unqualified individuals who would pose as “guiders.” Recognizing the importance of the public menace that actually exists in almost every section of the country, the National Vocational Guidance Association has provided a committee to conduct a national investigation and suggest possible licensing measures. Dean Davis is chairman of that committee.
Training and Selection of School Counselors
Authors: WILLIAMSON E. G.
Published: February 2012

If educational and vocational counseling are to continue in their advancement there must be greater vigilance by schools and colleges of education in the selection and training of applicants. Of equal importance is progress toward recognition for qualified counselors through acceptable standards of certification, Dr. Williamson said in this address at the 1939 convention of the National Vocational Guidance Association.
Grooming Youth for the Job Market
Authors: COOPER RUTH G.
Published: February 2012

Here is an article that describes a service of giving information about jobs, appraising capacities of individuals, grooming them for specific jobs, and following them up after placement. It presents several unique features that will be of interest to a variety of readers.
Near‐infrared fluorescence imaging of mouse myocardial microvascular endothelium using Cy5.5‐lectin conjugate
Authors: Nguyen Cecilia , Bascaramurty Saro , Kuzio Bozena , Gregorash Lori , Kupriyanov Valery , Jilkina Olga
Published: February 2012

Cy5.5‐lectin, a non‐toxic conjugate, combines the benefits of near‐infrared (NIR) imaging, such as significant reduction of background fluorescence and increased tissue depth penetration, with its affinity for vascular endothelial cells. When compared to endothelial staining methods using FITC‐lectin and ICAM2 antibodies, Cy5.5‐lectin was confirmed to specifically bind endothelial cells and produce a fluorescence signal both in real‐time and post‐infusion. Ex‐vivo experiments with isolated hearts demonstrated that binding was limited to perfused areas of the myocardium. With mouse in‐vivo tail‐vein injections, other organs such as the liver, spleen, and kidney were also stained and yielded similar quality images of the heart. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Monte Carlo Simulation of the Microstructure of Linear Olefin Block Copolymers
Authors: Anantawaraskul Siripon , Somnukguande Punnawit , Soares João B.P.
Published: February 2012

Summary: Linear olefin block copolymers (OBCs) are novel polyolefins with unique properties developed using the chain shuttling polymerization technology. Typically, OBCs are made in a single reactor with two catalysts having different 1‐olefin reactivity ratios and a chain shuttling agent (CSA), producing linear polymer chains with complex, multi‐block structures, although a dual reactor approach is also possible In this study, OBC chain microstructures were examined using Monte Carlo simulation. Effects of polymerization parameters (chain shuttling probability, propagation probability, and catalyst ratio) on the distribution of number of blocks per chain were investigated and reported for the first time. These results provide useful insights on how to control and describe the microstructures of these important polymers and can be used to establish quantitative relationships between the microstructure and properties of OBCs.
Probing Liquid‐Liquid Phase Separation of a Polyethylene Blend with Thermal Analysis
Authors: Ren Minqiao , Wu Changjiang , Sheng Jianfang , Guo Meifang , Chen Erqiang
Published: February 2012

Summary: A series of polyethylene (PE) blends consisting of a high density polyethylene (HDPE) and a linear low density polyethylene (LLDPE) with a butene‐chain branch density of 77/1000 carbon was prepared at different concentrations. The LLDPE only crystallized below 50 °C, therefore, above 80 °C and below the melting temperature of HDPE, only HDPE crystallized in the PE blends. A specifically designed multi‐step experimental procedure based on thermal analysis technique was utilized to monitor the liquid–liquid phase separation (LLPS) of this set of PE blends. The main step was first to quench the system from the homogeneous temperatures and isothermally anneal them at a prescribed temperature higher than the equilibrium melting temperature of the HDPE for the purpose of allowing the phase morphology to develop from LLPS, and then cool the system at constant rate to record the non‐isothermal crystallization. The crystallization peak temperature (Tp) was used to character the crystallization rate. Because LLPS results in HDPE‐rich domains where the crystallization rates are increased, this technique provided an experimental measure to identify the binodal curve of the LLPS for the system indicated by increased Tp. The result showed that the LLPS boundary of the blend measured by this method was close to that obtained by phase contrast optical microscopy method. Therefore, we considered that the thermal analysis technique based on the non‐isothermal crystallization could be effective to investigate the LLPS of PE blends.
Morphology and Stress Whitening of Heterophasic Poly(propylene) Copolymer/High Density Polyethylene Blends
Authors: Jang Hee Jung , Kim Soon‐Deok , Choi Wonsook , Chun Yong Sung
Published: February 2012

Summary: Effect of high density polyethylene (HDPE) addition on the morphology of heterophasic poly(propylene) copolymer (HPC) was investigated by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Stress whitening developed upon dart impact was evaluated using Gardner‐type impact tester. In the TEM study of HPC/HDPE blends, a core‐shell morphology was observed of HDPE encapsulated by ethylene‐propylene rubber (EPR). At low HDPE weight fractions (95/5 and 90/10 HPC/HDPE), the size of dispersed phase increased compared to pure HPC. However, further increase in HDPE leads to a decrease in domain size. The impact strength reached a maximum at 90/10 HPC/HDPE blend, and then decreased with further increase in HDPE content. The stress whitening of HPC was decreased with addition of HDPE. This decrease is attributed to the difference in the shrinkage between HPC and HPC/HDPE blends. The pressure‐volume‐temperature relationship supports that an additional volume contraction of HDPE can reduce the stress whitening of HPC.
Stereochemical behavior of 77Se‐1H spin‐spin coupling constants in pyrazolyl‐1,3‐diselenanes and 1,2‐diselenolane
Authors: Rusakov Yury Yu. , Krivdin Leonid B. , Papernaya Lyubov K. , Shatrova Alexandra A.
Published: February 2012

Conformational study of five derivatives of 2‐(pyrazol‐4‐yl)‐1,3‐diselenane together with related 1,2‐diselenolane in respect to the stereochemical trends of geminal and vicinal 77Se‐1H spin‐spin coupling constants has been carried out by means of high‐level theoretical calculations in combination with experiment. The marked dihedral angle dependences for both types of couplings accounted for the lone pair effect in the case of geminal coupling constants and the Karplus‐type relationship for vicinal couplings have been established, which is of major importance for the stereochemical analysis of saturated selenium containing heterocycles. Copyright © 2012 John Wiley & Sons, Ltd.
Evolution of induced fabric in a strain space multiple mechanism model for granular materials
Authors: Iai Susumu , Tobita Tetsuo , Ozutsumi Osamu
Published: February 2012

The strain space multiple mechanism model idealizes the behavior of granular materials based on a multitude of virtual simple shear mechanisms oriented in arbitrary directions. Within this modeling framework, the virtual simple shear stress is defined as a quantity that depends on the contact distribution function as well as the normal and tangential components of inter‐particle contact forces, which evolve independently during the loading process. In other terms, the virtual simple shear stress is an intermediate quantity in the upscaling process from the microscopic level (characterized by the contact distribution and inter‐particle contact forces). The stress space fabric (i.e. the orientation distribution of the virtual simple shear stress) produces macroscopic stress through the tensorial average. Thus, the stress space fabric characterizes the fundamental and higher modes of anisotropy induced in granular materials. Comparing an induced fabric associated with the biaxial shear of plane granular assemblies obtained via a simulation using Discrete Element Method to the strain space multiple mechanism model suggests that the strain space multiple mechanism model has the capability to capture the essential features in the evolution of an induced fabric in granular materials. Copyright © 2012 John Wiley & Sons, Ltd.
A representation method for describing a deagglomerating process in continuous mixer
Authors: Xie Linsheng , Li Peinin , Ma Yulu , Sha Jin
Published: February 2012

An improved analysis method based on two parameters: deagglomerating energy density and average deagglomerating energy is proposed in this work to describe the deagglomerating capacity and deagglomerating effect of the mixing flow field. This improved method combined with experimental results demonstrate that deagglomerating energy density can represent the deagglomerating capacity of flow field, and average deagglomerating energy is able to stand for the deagglomerating effect of agglomerate in mixing process. POLYM. COMPOS. 2012. © 2012 Society of Plastics Engineers
Criteria for improving the properties of ZnGeAs2 solar cells
Authors: Peshek Timothy J. , Zhang Lei , Singh Rakesh K. , Tang ZhiZhong , Vahidi Mahmoud , To Bobby , Coutts Timothy J. , Gessert Timothy A. , Newman Nathan , van Schilfgaarde Mark
Published: February 2012

We explore the potential utility of the II‐IV‐V semiconductor ZnGeAs2 as the absorber material in solar cells. As‐deposited ZnGeAs2 films prepared by pulsed laser deposition are amorphous because of the limited substrate temperature that can be used without the rapid loss of volatile Zn and As. Thermal processing above 450 °C results in crystallization and improved electrical properties with hole mobilities as high as 58 cm2/V s. The annealed films were used to fabricate p‐type ZnGeAs2: n‐type CdS cells on SnO2‐buffered borosilicate glass substrates in the so‐called superstrate geometry. Light‐induced currents of up to ~2 mA/cm2 and open‐circuit voltages of up to 470 mV were observed using backside illumination, indicating that these nascent devices hold potential for realizing high performance solar cells from earth‐abundant elements. The performance of the devices fabricated to‐date is degraded by conduction through shorts resulting from the presence of micron‐sized pinholes in the absorber layer. Copyright © 2012 John Wiley & Sons, Ltd.
Cognitive Responses to Sociocultural Elements in Professional Graduate Programs: Two Case Studies
Authors: Uhrig Karl
Published: February 2012

This article examines the sociocognitive context of two international students in academic programs in the United States. Bandura (2001) defines sociocognition as the interaction between an individual and the sociocultural elements that comprise his or her learning environment. Research in English for academic purposes has included more focus on these elements, resulting in emergent themes in the categories of workload management, success orientation, and social relationships. This study uses these categories in analysis of study logs, interviews, and documents to explore the sociocognitive responses of a student in a master of business administration (MBA) program and a student in a master of laws program during their first two semesters. The results indicate that their responses were mediated by their academic disciplines, including the teamwork requirements in the MBA program and the competitive atmosphere of the law school, as well as individual factors, including one participant's tendency to seek out classmates as study partners and the other's tendency to focus on his inner resources.
Advancing the Speaking and Listening Skills of K–2 English Language Learners Through Creative Drama
Authors: Brouillette Liane
Published: February 2012

In recent decades the United States has experienced a dramatic increase in children entering school whose home language is not English. If they are to achieve to their full potential, these children need direct and frequent interaction with individuals who can provide English language learners with accurate feedback. Creative drama activities that allow for the use of nonverbal communication in combination with verbal interactions can be an effective way for teachers to directly interact with many children at once, providing feedback and building vocabulary. This article describes a standards‐based creative drama curriculum designed to enhance K–2 English‐language development. Readers are invited to download lesson materials developed by the San Diego Unified School District and the University of California, Irvine, as well as to view online streaming videos of classroom interactions.
Overview of the West African Monsoon 20111
Authors: Cornforth Rosalind
Published: February 2012

The 2011 West African monsoon (WAM) season was, overall, near normal but rainfall was patchy. The irregularity of the rainfall during the crucial July‐August‐September (JAS) season proved difficult to predict because of conflicting signals and this highlights the significant challenges we continue to face for this region. The vagaries of the rainfall in sub‐Saharan Africa have profound and often dire effects on African society and economy as the people of the region depend on it for food and water. To reduce the vulnerability of these communities to variations in the strength of the WAM, we desperately need to improve the reliability of forecasts so as to enable them to plan ahead, and national governments need to adopt coordinated policies in order to increase their capacity to cope with extended periods of water shortages due to drought. With the launch of the Africa Climate Exchange (Afclix), the UK climate community is working with the humanitarian sector and African policy‐makers with the aim of channeling the latest climate science into policies to help build resilience and in‐country capacity for climate compatible development in sub‐Saharan Africa. The emphasis is on ‘feet on the (African) ground’ mechanisms of knowledge‐sharing activities at the science‐policy interface. Copyright © 2012 Royal Meteorological Society
The Right and Wrong of Growing Old: Assessing the Argument from Evolution
Authors: Foddy Bennett
Published: February 2012

One argument which is frequently levelled against the enhancement of human biology is that we do not understand the evolved function of our bodies well enough to meddle in our biology without producing unintended and potentially catastrophic effects. In particular, this argument is levelled against attempts to slow or eliminate the processes of human ageing, or ‘senescence’, which cause us to grow decrepit before we die. In this article, I claim that even if this argument could usefully be applied against attempts to enhance other human traits, it cannot be valid in the case of attempts to enhance the various processes that constitute senescence. I begin by reviewing the biology of ageing to show how it consists of a number of unrelated traits. Then, following the arguments of a number of evolutionary biologists, I explain that every one of these traits is a product of evolutionary ‘neglect’ rather than ‘intent’. Finally, I consider the strongest version of the argument against enhancing senescence, which acknowledges these facts about the evolution of ageing but insists that we have nevertheless have prudential reasons to avoid enhancement wherever there is some uncertainty about the genetics or evolutionary function of a trait. I provide two reasons for rejecting this version of the argument as well, even in the case of human senescence, where such uncertainty is currently significant.
Prenatal Health, Educational Attainment, and Intergenerational Inequality: The Northern Finland Birth Cohort 1966 Study
Authors: Härkönen Juho , Kaymakçalan Hande , Mäki Pirjo , Taanila Anja
Published: February 2012

In this article, we study the effects of prenatal health on educational attainment and on the reproduction of family background inequalities in education. Using Finnish birth cohort data, we analyze several maternal and fetal health variables, many of which have not been featured in the literature on long-term socioeconomic effects of health despite the effects of these variables on birth and short-term health outcomes. We find strong negative effects of mother’s prenatal smoking on educational attainment, which are stronger if the mother smoked heavily but are not significant if she quit during the first trimester. Anemia during pregnancy is also associated with lower levels of attained education. Other indicators of prenatal health (pre-pregnancy obesity, mother’s antenatal depressed mood, hypertension and preeclampsia, early prenatal care visits, premature birth, and small size for gestational age) do not predict educational attainment. Our measures explain little of the educational inequalities by parents’ class or education. However, smoking explains 12%—and all health variables together, 19%—of the lower educational attainment of children born to unmarried mothers. Our findings point to the usefulness of proximate health measures in addition to general ones. They also point to the potentially important role played by early health in intergenerational processes.
Miscible displacement flows in near-horizontal ducts at low Atwood number
Authors: Taghavi S. M. , Alba K. , Seon T. , Wielage-Burchard K. , Martinez D. M. , Frigaard I. A.
Published: February 2012

We study buoyant displacement flows with two miscible fluids of equal viscosity in the regime of low Atwood number and in ducts that are inclined close to horizontal. Using a combination of experimental, computational and analytical methods, we characterize the transitions in the flow regimes between inertial- and viscous-dominated regimes, and as the displacement flow rate is gradually increased. Three dimensionless groups largely describe these flows: densimetric Froude number $\mathit{Fr}$, Reynolds number $\mathit{Re}$ and duct inclination $\ensuremath{\beta} $. Our results show that the flow regimes collapse into regions in a two-dimensional $(\mathit{Fr}, \mathit{Re}\cos \ensuremath{\beta} / \mathit{Fr})$ plane. These regions are qualitatively similar between pipes and plane channels, although viscous effects are more extensive in pipes. In each regime, we are able to give a leading-order estimate for the velocity of the leading displacement front, which is effectively a measure of displacement efficiency.
The Ivory Tower: the history of a figure of speech and its cultural uses
Authors: SHAPIN STEVEN
Published: February 2012

This is a historical survey of how and why the notion of the Ivory Tower became part of twentieth- and twenty-first-century cultural vocabularies. It very briefly tracks the origins of the tag in antiquity, documents its nineteenth-century resurgence in literary and aesthetic culture, and more carefully assesses the political and intellectual circumstances, especially in the 1930s and 1940s, in which it became a common phrase attached to universities and to features of science and in which it became a way of criticizing practices and institutions deemed to be ‘irrelevant’. The paper concludes by reflecting on the tag's relationship to pervasive cultural tropes and how its modern history may be used to appreciate better where science and its academic setting now stand in the ancient debate between the active and contemplative lives.
Metabolite movement across the schistosome surface
Authors: Da'dara A. , Krautz-Peterson G. , Faghiri Z. , Skelly P.J.
Published: February 2012

Intravascular schistosome parasites are covered by an unusual double lipid bilayer. Nutrients, such as glucose and amino acids, as well as other metabolites, are known to be transported across this surface via specific transporter proteins. For instance, the glucose transporter protein SGTP4 is found in the host-interactive tegumental membranes. A second glucose transporter, SGTP1, localizes to the tegumental basal membrane (and internal tissues). Following expression inXenopusoocytes, SGTP1 and SGTP4 both function as facilitated-diffusion sugar transporters. Suppressing the expression of SGTP1 and SGTP4 in juvenile schistosomes using RNA interference (RNAi) impairs the parasite's ability to import glucose and severely decreases worm viability. Amino acids can also be imported into schistosomes across their surface and an amino acid transporter (SPRM1lc) has been localized in the parasite surface membranes (as well as internally). InXenopusoocytes, SPRM1lc can import the basic amino acids arginine, lysine and histidine as well as leucine, phenylalanine, methionine and glutamine. To function, this protein requires the assistance of a heavy-chain partner (SPRM1hc) which acts as a chaperone. Water is transported across the tegument of schistosomes via the aquaporin protein SmAQP. Suppressing SmAQP gene expression makes the parasites less able to osmoregulate and decreases their viability. In addition, SmAQP-suppressed adult parasites have been shown to be impaired in their ability to excrete lactate. Analysis of tegumental transporter proteins, as described in this report, is designed to generate a comprehensive understanding of the role of such proteins in promoting parasite survival by controlling the movement of metabolites into and out of the worms.
CO2 Laser acceleration of forward directed MeV proton beams in a gas target at critical plasma density
Authors: TSUNG F. , TOCHITSKY S. YA. , HABERBERGER D. J. , MORI W. B. , JOSHI C.
Published: February 2012

The generation of 1–5 MeV protons from the interaction of a 3 ps TW CO2 laser pulse with a gas target with a peak density around the critical plasma density has been studied by 2D particle-in-cell simulations. The proton acceleration in the preformed plasma with a symmetric, linearly ramped density distribution occurs via formation of sheath of the hot electrons on the back surface of the target. The maximum energy of the hot electrons and, hence, net acceleration of protons is mainly defined by Forward Raman scattering instability in the underdense part of the plasma. Forward directed ion beams from a debris free gaseous target can find an application as a high-brightness ion source-injector to a conventional accelerator operating up to kHz pulse repetition frequency.
On unstable electromagnetic radiation through nonlinear wave–particle interactions in presence of drift wave turbulence
Authors: DEKA P. N. , BORGOHAIN A.
Published: February 2012

A study on the generation of unstable electromagnetic wave through nonlinear wave–particle interactions in an inhomogeneous plasma has been presented. Drift wave turbulence, which is one of the common features of inhomogeneous plasma, is found to be strongly in phase relation with thermal particles. The plasma particles, accelerated by drift wave turbulence field, may transfer their energy to electromagnetic O-mode through a modulated field. This process has been described by Vlasov Maxwell system of equations. From the nonlinear dispersion relation for O-mode the growth rate has been estimated. It has been observed that growth of unstable O-mode may predict magnetospheric electromagnetic radiation phenomena.
Payments for ecosystem services in an African protected area: exploring issues of legitimacy, fairness, equity and effectiveness
Authors: Gross-Camp Nicole D. , Martin Adrian , McGuire Shawn , Kebede Bereket , Munyarukaza Joseph
Published: February 2012

We explore the potential for payments for ecosystem services (PES) to reconcile conservation and development goals, using a case study of an experimental PES intervention around the Nyungwe National Park in Rwanda. The scheme involves the purchase of biodiversity conservation services from local communities in four selected locations. Although a portion of the payment is awarded at the household level, it is the collective action of the community that determines the level of the payment. Contracts are negotiated annually and include performance indicators within each participating community. We examine the ability of PES to achieve conservation and development objectives, through three sub-questions: Is the PES scheme effective? Is it legitimate and fair? Is it equitable? Our findings indicate that the relationship between these evaluation criteria is complex, with both trade-offs and synergies. In this case study the effectiveness of PES is dependent on the equitable distribution of the payment, participants’ belief and acceptance of the service being paid for, institutional histories that aid in the establishment of legitimacy and fairness, and the complementary nature of PES to more conventional enforcement methods.
Gold for the Barbarians? Uniface Gold Medallions of the House of Constantine Found in Britain and Ireland
Authors: Bland Roger
Published: February 2012

The paper discusses a hitherto neglected group of five uniface gold medallions in the names of Constantine I and II, issued betweenc.a.d.318 and 337, found in Britain and Ireland. These have been found either beyond the frontier (three examples are from Ireland and one from Scotland) or close to it (one example is from Cumbria). It is suggested that they may have been produced as diplomatic gifts for peoples beyond the frontier or as payment forlaeti.
Revealing the shape of knowledge using an intersectionality lens: results of a scoping review on the health and health care of ethnocultural minority older adults
Authors: KOEHN SHARON , NEYSMITH SHEILA , KOBAYASHI KAREN , KHAMISA HAMISH
Published: February 2012

This paper uses an intersectionality theoretical lens to interrogate selected findings of a scoping review of published and grey literature on the health and health-care access of ethnocultural minority older adults. Our focus was on Canada and countries with similar immigrant populations and health-care systems. Approximately 3,300 source documents were reviewed covering the period 1980–2010: 816 met the eligibility criteria; 183 were Canadian. Summarised findings were presented to groups of older adults and care providers for critical review and discussion. Here we discuss the extent to which the literature accounts for the complexity of categories such as culture and ethnicity, recognises the compounding effects of multiple intersections of inequity that include social determinants of health as well as the specificities of immigration, and places the experience of those inequities within the context of systemic oppression. We found that Canada's two largest immigrant groups – Chinese and South Asians – had the highest representation in Canadian literature but, even for these groups, many topics remain unexplored and the heterogeneity within them is inadequately captured. Some qualitative literature, particularly in the health promotion and cultural competency domains, essentialises culture at the expense of other determinants and barriers, whereas the quantitative literature suffers from oversimplification of variables and their effects often due to the absence of proportionally representative data that captures the complexity of experience in minority groups.
Isospectral surfaces of genus two and three
Authors: BARDEN DENNIS , KANG HYUNSUK
Published: February 2012

We give examples of isospectral non-isometric surfaces of genus two and three with variable curvature, as well as hyperbolic orbifolds of genus two. We apply the first result to construct isospectral potentials on a Riemann surface of genus two.
The Fibonacci groups. II
Authors: Chalk C. P. , Johnson D. L.
Published: February 2012

Synopsis

Since the appearance of the article [15] to which this is a sequel, considerable progress has been made in the study of the groups F(r, n) of the title. It is therefore our intention to give a brief account of these developments before proceeding to our main theme, which is to apply the elegant and powerful methods of small cancellation theory to these groups. This has a variety of consequences, perhaps the most important of which is the generalisation to arbitrary r of Lyndon's proof that F(2, n) is infinite for n ≧ 11.
Token-reflexive, anaphoric and deictic functions of ‘here’
Authors: Fretheim Thorstein , Amfo Nana Aba Appiah , Vaskó Ildikó
Published: February 2012

There are basically three ways in which the reference of a token of the English proximal spatial indexicalhereand corresponding terms in other languages can be resolved in the context-dependent, pragmatic phase of the addressee's determination of the propositional content of an utterance that contains this adverbial adjunct. ‘Here’ may refer reflexively to the place of utterance, including minimally the spot occupied by the speaker (token-reflexive reference), it may be anaphoric upon a discourse antecedent that provides information necessary for identification of the referent (anaphoric reference), or resolution of the reference depends on information derived from processing of a perceptual stimulus (deictic reference). These three pragmatic paths to resolution of the reference of proximal spatial indexicals are not mutually exclusive, so they do not warrant postulation of lexical ambiguity, at least not the traditional kind of ambiguity based on differences in conceptual meaning.
The past, present and future of the Pite Saami language: Sociological factors and revitalization efforts
Authors: Valijärvi Riitta-Liisa , Wilbur Joshua
Published: February 2012

Our paper is a report on the past, current and future state of the endangered Pite Saami language (aka: Arjeplog Saami) spoken in Swedish Lapland. Our primary data come from interviews with Pite Saami individuals and our field observations. We estimate the vitality of Pite Saami based on the UNESCO Language Vitality Scale, taking into consideration factors such as the number of speakers, language attitudes and the quality of documentation. We also discuss the possible reasons for the decline of Pite Saami, report on the speakers’ views of other Saami languages and Swedish, consider whether there is a specific Pite Saami identity, describe revitalization efforts already taking place, and discuss the future prospects of the language.
Transmission and strain variation of Shigella flexneri 4a after mass prophylaxis in a long-stay psychiatric centre
Authors: KO C. F. , WANG L. Y. , LIN N. T. , CHIOU C. S. , YEH H. C. , RENN J. H. , LEE Y. S.
Published: February 2012

Shigella flexneri 4a caused sustained outbreaks in a large long-stay psychiatric centre, Taiwan, 2001–2006. Trimethoprim-sulphamethoxazole (SXT) prophylaxis was administered in 2004. We recovered 108 S. flexneri 4a isolates from 83 symptomatic (including one caregiver) and 12 asymptomatic subjects (11 contacts, one caregiver). The isolates were classified into eight antibiogram types and 15 genotypes (six clusters) by using antimicrobial susceptibility testing and pulsed-field gel electrophoresis of NotI-digested DNA, respectively. These characteristics altered significantly after SXT prophylaxis (P < 0·05), with concomitant emergence of SXT-resistant isolates in two antibiogram types. P01 (n = 71), the predominant epidemic genotype, caused infection in two caregivers and five patients under their care; two P01 isolates were recovered from the same patient 6 months apart. These results indicate the importance of sustained person-to-person transmission of S. flexneri 4a by long-term convalescent, asymptomatic or caregiver carriers, and support the emergence of SXT-resistant strains following selective pressure by SXT prophylaxis.
L'ANGLE DE CONTINGENCE: UN PROBLÈME DE PHILOSOPHIE DES MATHÉMATIQUES
Authors: Rashed Roshdi
Published: February 2012

From Euclid to the second half of the 17th century, mathematicians as well as philosophers continued to raise the question of the angle of contact and, generally, of the concept of angle. This article is the first essay devoted to this subject in Arabic mathematics. It deals with Greek writings translated into Arabic on the one hand, and contributions of Arabic mathematicians on the other hand: al-Nayrīzī, Ibn al-Haytham, al-Samawʾal, al-Shīrāzī, al-Fārisī, al-Qūshjī, among others. Most of these contributions are hitherto unknown.
CREATIO EX NIHILO– A GENUINELY PHILOSOPHICAL INSIGHT DERIVED FROM PLATO AND ARISTOTLE? SOME NOTES ON THETREATISE ON THE HARMONY BETWEEN THE TWO SAGES
Authors: Gleede Benjamin
Published: February 2012

The article aims at demonstrating that in attributing thecreatio ex nihiloto both Plato and Aristotle as their unanimous philosophical conviction theTreatise on the Harmony between the Two Sagesdeeply depends upon the Neoplatonic reading of those two philosophers. The main obstacles for such a view in the works of the two sages are Plato's assumption of a precosmic chaos in theTimaeusand Aristotle's denial of any efficient causality to the unmoved mover in theMetaphysics. Both of these points had been, however, done away with by the Neoplatonist commentators already, especially by Ammonius in his lost treatise on efficient and final causality in Aristotle the use of which in theHarmonyis shown by a comparison with Simplicius. Christian and Muslim readers just had to transfer those arguments and hermeneutical techniques into an anti-eternalist context in order to make the two philosophers agree with one of the basic tenents of their face, a hermeneutical technique considerably different from the one employed by al-Fārābī in his exposition of Plato's and Aristotle's philosophy which is compared to theHarmonyin a briefly sketched concluding section.
Bayesian over-dispersed Poisson model and the Bornhuetter & Ferguson claims reserving method
Authors: England Peter D. , Verrall Richard J. , Wüthrich Mario V.
Published: February 2012

We consider the Bayesian over-dispersed Poisson (ODP) model for claims reserving in general insurance. We choose two different types of prior distributions for the parameters and then study the different Bayesian predictors. This study leads, on the one hand, to the classical chain ladder predictor and, on the other hand, to Bornhuetter & Ferguson predictors. We highlight (either analytically or numerically) how these predictors are obtained and how their prediction uncertainty can be determined.
Is a bipolar seesaw consistent with observed Antarctic climate variability and trends?
Authors: Schneider David P. , Noone David C.
Published: February 2012

A bipolar seesaw of Arctic and Antarctic temperature anomalies has been reported to be evident in instrumental data on decadal timescales during the last century. This finding hinges upon a global temperature data set that for the area poleward of ∼60°S is derived from only one sub‐Antarctic station prior to the mid‐1940s, and does not include a substantial number of Antarctic stations until the late 1950s. The timeseries of the single‐station record for the early period spliced to the data based on broader coverage for the latter period is an artificial estimate of the Antarctic climate trend and its variability. We estimate the real variability using the original timeseries from the sub‐Antarctic station, a reconstruction of the Southern Annular Mode index, and an ice‐core based reconstruction of Antarctic temperature. None of these Antarctic timeseries are significantly correlated with Arctic or North Atlantic climate records, nor with the index of the Atlantic Multidecadal Oscillation, which was proposed as the driving mechanism of the seesaw. Instead, each of these records is consistently correlated with tropical Pacific sea surface temperatures. However, neither the seesaw nor the tropics alone can fully capture the complexity of Antarctic climate variability and climate change.
Relative contributions of temperature and salinity to seasonal mixed layer density changes and horizontal density gradients
Authors: Johnson Gregory C. , Schmidtko Sunke , Lyman John M.
Published: February 2012

Temperature and salinity both contribute to ocean density, including its seasonal cycle and spatial patterns in the mixed layer. Temperature and salinity profiles from the Argo Program allow construction and analysis of a global, monthly, mixed layer climatology. Temperature changes dominate the seasonal cycle of mixed layer density in most regions, but salinity changes are dominant in the tropical warm pools, Arctic, and Antarctic. Under the Intertropical Convergence Zone, temperature and salinity work in concert to increase seasonal stratification, but the seasonal density changes there are weak because the temperature and salinity changes are small. In the eastern subtropics, seasonal salinity changes partly compensate those in temperature and reduce seasonal mixed layer density changes. Besides a hemispheric seasonal reversal, the times of maximum and minimum mixed layer density exhibit regional variations. For instance, the equatorial region is more closely aligned with Southern Hemisphere timing, and much of the North Indian Ocean has a minimum density in May and June. Outside of the tropics, the maximum mixed layer density occurs later in the winter toward the poles, and the minimum earlier in the summer. Finally, at the times of maximum mixed layer density, some of the ocean has horizontal temperature and salinity gradients that work against each other to reduce the horizontal density gradient. However, on the equatorial sides of the subtropical salinity maxima, temperature and salinity gradients reinforce each other, increasing the density gradients there. Density gradients are generally stronger where either salinity or temperature gradients are dominant influences.
Land use/land cover and scale influences on in‐stream nitrogen uptake kinetics
Authors: Covino Tim , McGlynn Brian , McNamara Rebecca
Published: February 2012

Land use/land cover change often leads to increased nutrient loading to streams; however, its influence on stream ecosystem nutrient transport remains poorly understood. Given the deleterious impacts elevated nutrient loading can have on aquatic ecosystems, it is imperative to improve understanding of nutrient retention capacities across stream scales and watershed development gradients. We performed 17 nutrient addition experiments on six streams across the West Fork Gallatin Watershed, Montana, USA, to quantify nitrogen uptake kinetics and retention dynamics across stream sizes (first to fourth order) and along a watershed development gradient. We observed that stream nitrogen (N) uptake kinetics and spiraling parameters varied across streams of different development intensity and scale. In more developed watersheds we observed a fertilization affect. This fertilization affect was evident as increased ash‐free dry mass, chlorophylla, and ambient and maximum uptake rates in developed as compared to undeveloped streams. Ash‐free dry mass, chlorophylla, and the number of structures in a subwatershed were significantly correlated to nutrient spiraling and kinetic parameters, while ambient and average annual N concentrations were not. Additionally, increased maximum uptake capacities in developed streams contributed to low in‐stream nutrient concentrations during the growing season, and helped maintain watershed export at low levels during base flow. Our results indicate that land use/land cover change can enhance in‐stream uptake of limiting nutrients and highlight the need for improved understanding of the watershed dynamics that control nutrient export across scales and development intensities for mitigation and protection of aquatic ecosystems.