bluuebunny/crossref_metadata_2025 huggingface dataset:
Differences in gas exchange contribute to habitat differentiation in Iberian columbines from contrasting light and water environments
Authors: Jaime R. , Serichol C. , Alcántara J. M. , Rey P. J.
Published: August 2013

During photosynthesis, respiration and transpiration, gas exchange occursviathe stomata and so plants face a trade‐off between maximising photosynthesis while minimising transpiration (expressed as water use efficiency,WUE). The ability to cope with this trade‐off and regulate photosynthetic rate and stomatal conductance may be related to niche differentiation between closely related species. The present study explored this as a possible mechanism for habitat differentiation in Iberian columbines. The roles of irradiance and water stress were assessed to determine niche differentiation among Iberian columbinesviadistinct gas exchange processes. Photosynthesis–irradiance curves (P–I curves) were obtained for four taxa, and common garden experiments were conducted to examine plant responses to water and irradiance stress, by measuring instantaneous gas exchange and plant performance. Gas exchange was also measured in ten individuals using two to four field populations per taxon. The taxa had different P–I curves and gas exchange in the field. At the species level, water stress and irradiance explained habitat differentiation. Within each species, a combination of irradiance and water stress explained the between‐subspecies habitat differentiation. Despite differences in stomatal conductance andCO2assimilation, taxa did not have differentWUEunder field conditions, which suggests that the environment equally modifies photosynthesis and transpiration. The P–I curves, gas exchange in the field and plant responses to experimental water and irradiance stresses support the hypothesis that habitat differentiation is associated with differences among taxa in tolerance to abiotic stress mediated by distinct gas exchange responses.
Targeted destruction of fungal structures of Erysiphe trifoliorum on flat leaf surfaces of Marchantia polymorpha
Authors: Takikawa Y. , Senga Y. , Nonomura T. , Matsuda Y. , Kakutani K. , Toyoda H.
Published: August 2013

In this study, we observed the germination behaviour of airborne conidia from powdery mildews that settle on thalloid surfaces. We inoculated thalli (flat, sheet‐like leaf tissues) and gemmae (small, flat, sheet‐like leaf tissues that propagate asexually via bud‐like structures) of the common liverwort (Marchantia polymorpha) with conidia from tomato powdery mildew (Oidium neolycopersici; KTP‐02) and red clover powdery mildew (Erysiphe trifoliorum; KRCP‐4N) and examined their germination and subsequent appressorium formation under a high‐fidelity digital microscope. Conidial bodies and germ tubes of the inoculated KRCP‐4N conidia were destroyed on both the thalli and gemmae. The destruction of these fungal structures was observed only for KRCP‐4N conidia inoculated onto M. polymorpha on both leaf surfaces. No differences in destruction of the KRCP‐4N fungal structures between thalli and gemmae were observed. At 4 h post‐inoculation, destruction of the germ tube tip was observed when it reached the gemmae leaf surface. At 6 h post‐inoculation, the conidial bodies and germ tubes were destroyed. In contrast, KTP‐02 conidia were not destroyed and formed normal, well‐lobed appressoria on the surface of M. polymorpha gemmae.
Face‐Off: Facial Features and Strategic Choice
Authors: Tingley Dustin
Published: August 2013

I study experimentally a single‐shot trust game where players have the opportunity to choose an avatar—a computer‐generated face—to represent them. These avatars vary on several dimensions—trustworthiness, dominance, and threat—identified by previous work as influencing perceptions of those who view the faces (Todorov, Said, Engell, & Oosterhof, 2008). I take this previous work and ask whether subjects choose faces that are ex ante more trustworthy, whether selected avatars have an influence on strategy choices, and whether individuals who evaluate faces as more trustworthy are also more likely to trust others. Results indicate affirmative answers to all three questions. Additional experimental sessions used randomly assigned avatars. This design allows me to compare behavior when everyone knows avatars are self‐selected versus when everyone knows they are randomly assigned. Random assignment eliminated all three effects observed when subjects chose their avatars.
Personality Traits (“Big Five”) and the Propensity to Political Protest: Alternative Models
Authors: Brandstätter Hermann , Opp Karl‐Dieter
Published: August 2013

In a representative panel study, citizens of Leipzig (EastGermany) were interviewed in 1993 and 1996 about their incentives for and participation in political protest activities. Conscientiousness, neuroticism, agreeableness, openness to experience, and extraversion (theBig Five) were measured with 16 bipolar adjectives. The present report supplements a previous work of the authors that drew on the theories of rational choice and collective action and conceived of incentives as proximal causes and personality dispositions as distant causes of political protest. Based on structural equation modelling (SEM), the present article deals with the respondents' recurrent reports on protest incentives and protest acts as indicators of the latent constructprotest propensitythat is according to the predictions directly influenced by openness to experience (O+), agreeableness (A−), neuroticism (N−), and reciprocity orientation (N*E+) with 35% explained variance.
The (Identification) Cards You Are Dealt: Biased Treatment ofAnglos andLatinos Using Municipal‐Issued versus UnofficialIDCards
Authors: Ditlmann Ruth K. , Lagunes Paul
Published: August 2013

The current field experiment investigated if and howLatinos versusAnglos experience biased treatment in a setting where documentation is relevant. In an audit experiment, Latino customers were treated differently than a matched team ofAnglo customers when making $10 check payments at retail stores. Specifically,Latinos were asked to present an identification card (ID) more frequently thanAnglo customers, were quoted a higher minimum‐dollar amount for purchasing a gift certificate, and received more negative affect from salespersons. Among those who were asked for identification, a municipal‐issuedIDcard was declined at equal rates fromLatinos andAnglos, while an unofficialIDcard was declined more fromAnglos thanLatinos. The association of Latino identity with foreignness and undocumented immigration, and the potential of municipal‐IDcard programs to serve undocumented immigrants are discussed.
A Taste for Justice: Unpacking Identity Politics in a Nascent Democracy
Authors: Epstein Liana Maris , Goff Phillip Atiba , Huo Yuen J. , Wong Lauren Hitomi
Published: August 2013

This article examines attention to justice cues in the novel context of the nascent democracy of Tanzania. Using secondary national survey data, we illustrate Tanzanian citizens' attention to justice cues. We then test two competing hypotheses about the impact of religious identity on attention to justice cues. The first hypothesized model, based on System Justification Theory, predicts that subordinate group members (Muslims) will stay more loyal than dominant group members (Christians) to their government due to a decreased attention to justice cues. The second hypothesized model, based on the relational model of procedural justice, predicts that subordinate group members (Muslims) will dissent more than dominant group members (Christians) from their government due to an increased attention to justice cues. Multiple regression and mediational analyses indicate support for the procedural justice framework, with trust in the dominant political party mediating the relationship between process satisfaction and party identification. Implications for political and psychological theorizing about democratic processes will be discussed.
A Cognitive Anatomy of Political Trust and Respective Bases: Evidence from a Two‐City Survey inChina
Authors: Lu Jie
Published: August 2013

Building on contemporary research on social cognition and psychology, trust, political representation and accountability, and candidate evaluation, this article proposes to decompose political trust into two cognitively distinct but related components for examination: competence versus intention evaluations. This article further argues that people's evaluations of their government's competence and intention in governance can have distinct bases due to the varying accessibility of pertinent information. Using valid instruments from a unique sampling survey in twoChinese cities in 2005, this article tests the validity of this cognitive scheme. Empirical evidence shows that (1) the surveyedChinese urban residents effectively differentiated between their central government's competence and intention in governance: on average, they had a quite positive assessment of the central government's intention to serve its people, despite their relatively pessimistic views of its competence to deliver good governance; (2) theChinese urbanites did consult different sources of information and heuristics when evaluating their central government's competence and intention, respectively.
New Technologies, New Identities, and the Growth of Mass Opposition in the Arab Spring
Authors: McGarty Craig , Thomas Emma F. , Lala Girish , Smith Laura G. E. , Bliuc Ana‐Maria
Published: August 2013

The recent revolutions known as the Arab Spring have been characterized as the products of social media. However, there is an alternative view that revolution takes place on the street or the battlefield and that the role of social media has been overstated. We argue that some new technologies can serve to facilitate rapid social change when they provide ways to overcome restrictions on the freedoms of expression and association. In doing so, communication technologies enable the formation of new social identities that can challenge existing social orders by promoting the growth of a social movement that is positioned as loyal to the nation and its people but opposed to the government. Our analyses focus on the role of social media in spreading video images of dissent and the links between this video material, satellite television, and mobile telephones in Tunisia and Egypt.
The Differential Effects of Right‐Wing Authoritarianism and Social Dominance Orientation on Political Intolerance
Authors: Crawford Jarret T. , Pilanski Jane M.
Published: August 2013

Decades of scholarship have identified several determinants of political intolerance, including authoritarianism and normative threat. Previous attempts in the literature to associate other individual difference variables (i.e., social dominance orientation [SDO]) and situational variables (i.e., out‐groups' gains in power and status) have been unsuccessful. Using a dual‐process motivational (DPM) model framework, in Study 1 we found that SDO predicted political intolerance of groups with hierarchy‐attenuating political objectives. This relationship was consistent over and above other well‐known predictors of political intolerance, including right‐wing authoritarianism (RWA). RWA predicted intolerance of groups with both hierarchy‐attenuating and cohesion‐reducing objectives. In Study 2, we manipulated whether an immigrant‐rights group was described as presenting a normative threat or as gaining power and status. Consistent with extant findings, RWA moderated the effect of normative threat on political intolerance. More interestingly, SDO moderated the effect of gains in power and status on political intolerance. The implications of these findings are discussed.
Oral health champions in long‐term care facilities—a pilot study
Authors: Amerine Carol , Boyd Linda , Bowen Denise M. , Neill Karen , Johnson Tara , Peterson Teri
Published: August 2013

This preintervention/postintervention pilot study examined impact of onsite support by a dental hygiene champion (DHC) on oral health and quality of life (QOL) of elderly residents in three long‐term care facilities (LTCFs) in Arkansas. Oral health and oral health‐related QOL were operationalized using the Oral Health Assessment Tool (OHAT) and Geriatric Oral Health Assessment Index (GOHAI), respectively. CNAs in Facility A received standardized oral health education/materials with onsite DHC support. Facility B received education/materials only. Facility C served as control. Data analyses included Wilcoxon‐signed rank tests (OHAT) and repeated measures ANOVA (GOHAI) (p ≤ .05). OHAT postintervention data in Facility A showed significant improvements in three measured areas (tongue health, denture status, and oral cleanliness); in Facility B, one area (tongue health); and none in Facility C. No significant differences were found in GOHAI scores across facilities.

Findings suggest that the presence of DHCs in LTCFs may positively impact the oral health of CNA‐assisted residents.
Differences in V1 and V2 ski skating techniques described by accelerometers
Authors: Myklebust H. , Losnegard T. , Hallén J.
Published: August 2013

The aims of the study were to describe the differences between the ski skating techniques V1 and V2 and evaluate reproducibility in complex cyclic hip movements measured by accelerometers. Fourteen elite senior male cross‐country skiers rollerskied twice for 1 min (V1 and V2) at 4° inclination and 3 m/s. Tests were repeated after 20 min and again 4 months later. Five triaxial accelerometers were attached to the subject's hip (os sacrum), poles, and ski boots. Post‐processing included transforming to an approximately global coordinate system, normalization for cycle time, double integration for displacement, and revealing temporal patterns. Different acceleration patterns between techniques and large correlation coefficients (Pearson's r = 0.6–0.9) between repeated trials were seen for most parameters. In V2, the hip was lowered [−10.9 (1.2) cm], whereas in V1, the hip was elevated [4.8 (1.5) cm] during the pole thrust. In conclusion, V2 but not V1 showed similarities to double poling in the way that potential energy is gained between poling strokes and transferred to propulsion during the poling action. Elite skiers reproduce their own individual patterns. One triaxial accelerometer on the lower back can distinguish techniques and might be useful in field research as well as in providing individual feedback on daily technique training.
Prevalence, incidence and course of lower extremity injuries in runners during a 12‐month follow‐up period
Authors: van Poppel D. , Scholten‐Peeters G. G. M. , van Middelkoop M. , Verhagen A. P.
Published: August 2013

To describe the incidence, 12‐month prevalence, and course of lower extremity injuries that occurred during and after the Amgen Singelloop Breda in 2009. The design was based on a prospective cohort study with a population‐based setting. In total, 3605 registered runners received a web‐based baseline questionnaire of which 713 participants completed and returned it. Information about previous injuries, training programs, and demographic data were gathered at baseline. Site and intensity of running injuries and occurrence of new injuries were obtained from five post‐race questionnaires. The main outcome measurement was lower extremity injury. The incidence of running injuries during the Amgen Singelloop Breda itself was 7.8%; most of these injuries occurred in the calf muscle, thigh, and knee joint. Three‐month incidence of injuries during follow‐up varied between 13.5% and 16.3%. During the 12‐month follow‐up period, 277 new running injuries were reported. Runners who ran more than 10 km are more susceptible to injury in comparison with runners who ran short distances (10 km or less). In total, 69.1% of running injuries resolves within 10 days. Running injuries are very common among recreational runners. Injuries mostly occur in the knee, thigh, and calf muscle.
A novel HLA allele, HLA‐A*02:393, identified in a two generation Italian family
Authors: Longa L. A. , Perotti L. , Piovano F. , Prucca M. , Menardi G. , Peano G.
Published: August 2013

HLA‐A*02:393 differs by a single nucleotide substitution from both A*02:26 (A524G) and from A*02:40:01 (T527A)
Identification of a novel HLA‐B*40 allele, HLA‐B*40:211, in a Chinese individual
Authors: Sun Y. , Xie J. H. , Yang J. H. , Zheng J. W. , Liu Y. , Jiang Y. Q. , Tang Q. J. , Du K. M.
Published: August 2013

HLA‐B*40:211 allele differs from HLA‐B*40:02:01 by an amino acid exchange at position 132, which has a missense mutation in exon 3 from Ser to Tyr.
A nonsynonymous mutation at HLA‐E defines the new E*01:06 allele in Brazilian individuals
Authors: Veiga‐Castelli L. C. , Felício L. P. , Georg R. C. , Castelli E. C. , Donadi E. A.
Published: August 2013

We report a novel nonclassical class I HLA‐E*01:06 allele observed in Brazilian individuals.
Interleukin‐6 level and gene polymorphism in spontaneous miscarriage
Authors: Drozdzik M. , Szlarb N. , Kurzawski M.
Published: August 2013

The aetiology of spontaneous miscarriage, the most common pregnancy complication, remains undefined. One of postulated factors involved in miscarriage pathology is interleukin 6 (IL‐6). Therefore, the aim of the study was to evaluate IL‐6 and interleukin 6 receptor (IL‐6R) gene polymorphisms in patients with spontaneous miscarriage. One hundred fifty‐seven patients diagnosed with spontaneous miscarriage and age and gestational time matched controls were included in the case–control study. In all study participants circulating IL‐6 levels (chemiluminescent immunoassay) and IL6–174G>C as well as IL6R rs2228145:A>C polymorphisms were evaluated. The distribution of IL6 as well as IL6R alleles and genotypes were similar in the controls and patients with miscarriage. Only a trend of more frequent appearance of −174GC+CC and C allele in the patients with miscarriage was noted. Blood serum concentrations of IL‐6 were significantly elevated in patients with miscarriage vs those with physiological pregnancy. Likewise, IL‐6 concentrations differ significantly with the types of miscarriage. The highest concentrations of the cytokine was seen in subjects with incomplete miscarriage (4.28 ± 4.88 pg/ml) followed by imminent miscarriage (2.97 ± 2.42 pg/ml), and then missed miscarriage (2.07 ± 1.90 pg/ml), being significantly the lowest in missed miscarriage group. No association between the IL6 genotype and IL‐6 serum concentration were noted, both in the miscarriage group and in the control group. The findings of the study support the role of IL‐6 in spontaneous miscarriage irrespectively of its type. However, no correlation between circulating IL‐6 and IL6 gene polymorphism, as well as IL‐6 and IL‐6R polymorphisms associations with spontaneous miscarriage were revealed.
Discourse particles in Colloquial Singapore English
Authors: SMAKMAN DICK , WAGENAAR STEPHANIE
Published: August 2013

The research looked into choices by speakers of Colloquial Singapore English with different ethnicities (Chinese, Indian and Malay) in the use of particles whose roots lie not in English. The 76 speakers under investigation used 1,427 such particles in 30 conversations. The general rate of particle usage by the members of each ethnicity was similar. The particleslahandah, whose linguistic origins are unknown and which account for almost 94 per cent of the total particle use, were both frequently used across ethnic groups. The Chinese speakers used these articles less than the other two ethnicities and were more inclined than the other two groups to use Cantonese particles, especiallylor. Two other Cantonese particles,horandleh, were used six and nine times respectively, and these rare instances were exclusively produced by Chinese speakers. Indian speakers did not distinguish between the number of particles in intra‐ and interethnic settings, while the other two groups did, especially the Malay speakers, for this group the difference was significant. Our research shows that while ethnic patterns seem absent in the use of the most frequent CSE particles, infrequent particles may nevertheless reveal such patterns. Future research should focus on infrequent CSE particles.
Effects of policy on English‐medium instruction in Africa
Authors: KAMWANGAMALU NKONKO M.
Published: August 2013

This study examines the effects of policy on English‐medium instruction in public schools in Africa. The focus is on illiteracy and elite closure. It argues that policy on English‐medium instruction has failed to achieve the key objectives around which it was adopted: spread literacy among and create opportunities for the populace to participate in the socioeconomic and political development of the continent. The paper calls for an inclusive language policy that promotes a dual‐medium educational system including an English‐medium stream and a vernacular‐medium stream to achieve the purported objectives. It warns that for vernacular‐medium education to be accepted by the population, however, it must be vested with comparable material returns that are currently associated only with English‐medium education.
Language choice in multilingual socio‐religious settings in southwest Cameroon
Authors: KOUEGA JEAN‐PAUL , EMALEU CLAIRE‐SOLANGE
Published: August 2013

This paper examines the factors motivating language choice in church in two semi‐urban, multilingual localities of Anglophone Cameroon, namely, Kumba and Mundemba. The informants were priests, catechists, choir leaders and parishioners; and the data were collected through participant observation and a questionnaire. The structural‐functional model proposed by Kouega (2008) was adopted. The findings revealed amongst other facts, that the languages used in these two places were English, Pidgin English, Latin, Lingala and Lamnso’ and those used in one or the other locality were Oroko and Bamileke. These languages were found to be chosen for one or more of the following reasons: the priests were proficient in them, the parishioners understood them, there were religious materials available in them, there were choirs singing in them and, lastly, there existed a collection of captivating lyrics in them.
The language of Hinduism in the US diaspora
Authors: PANDHARIPANDE RAJESHWARI V.
Published: August 2013

The use of English in rituals in the Hindu diaspora in the US is a major change for the religion, since English is excluded from Hindu rituals in India. This paper demonstrates that: (a) this change has impacted the structure of English and the system of Hinduism; (b) Hindu saints, the ‘authority’ in Hinduism, sanction this change; (c) the media further promotes it; and (d) it impacts the degree of functional load and transparency for the languages of rituals while creating di‐systems, or mixed codes with two systems of thought. The implications of this discussion for the theory of language change, maintenance and loss of language will be presented.
Implosion for hyperkähler manifolds
Authors: Dancer Andrew , Kirwan Frances , Swann Andrew
Published: August 2013

We introduce an analogue in hyperkähler geometry of the symplectic implosion, in the case of$\mathrm{SU} (n)$actions. Our space is a stratified hyperkähler space which can be defined in terms of quiver diagrams. It also has a description as a non-reductive geometric invariant theory quotient.
Glicci ideals
Authors: Migliore Juan , Nagel Uwe
Published: August 2013

A central problem in liaison theory is to decide whether every arithmetically Cohen–Macaulay subscheme of projective $n$-space can be linked by a finite number of arithmetically Gorenstein schemes to a complete intersection. We show that this can indeed be achieved if the given scheme is also generically Gorenstein and we allow the links to take place in an $(n+ 1)$-dimensional projective space. For example, this result applies to all reduced arithmetically Cohen–Macaulay subschemes. We also show that every union of fat points in projective 3-space can be linked in the same space to a union of simple points in finitely many steps, and hence to a complete intersection in projective 4-space.
Positroid varieties: juggling and geometry
Authors: Knutson Allen , Lam Thomas , Speyer David E.
Published: August 2013

While the intersection of the Grassmannian Bruhat decompositions for all coordinate flags is an intractable mess, it turns out that the intersection of only the cyclic shifts of one Bruhat decomposition has many of the good properties of the Bruhat and Richardson decompositions. This decomposition coincides with the projection of the Richardson stratification of the flag manifold, studied by Lusztig, Rietsch, Brown–Goodearl–Yakimov and the present authors. However, its cyclic-invariance is hidden in this description. Postnikov gave many cyclic-invariant ways to index the strata, and we give a new one, by a subset of the affine Weyl group we call bounded juggling patterns. We call the strata positroid varieties. Applying results from [A. Knutson, T. Lam and D. Speyer, Projections of Richardson varieties, J. Reine Angew. Math., to appear, arXiv:1008.3939 [math.AG]], we show that positroid varieties are normal, Cohen–Macaulay, have rational singularities, and are defined as schemes by the vanishing of Plücker coordinates. We prove that their associated cohomology classes are represented by affine Stanley functions. This latter fact lets us connect Postnikov’s and Buch–Kresch–Tamvakis’ approaches to quantum Schubert calculus.
Electrohydrodynamic Conduction Driven Single- and Two-Phase Flow in Microchannels With Heat Transfer
Authors: Pearson Matthew R. , Seyed-Yagoobi Jamal
Published: August 2013

Microchannels have well-known applications in cooling because of their ability to handle large quantities of heat from small areas. Electrohydrodynamic (EHD) conduction pumping at the microscale has previously been demonstrated to effectively pump dielectric liquids through adiabatic microchannels by using electrodes that are flushed against the walls of the channel. In this study, an EHD micropump is used to pump liquid within a two-phase loop that contains a microchannel evaporator. Additional EHD electrodes are embedded within the evaporator, which can be energized separately from the adiabatic pump. The effect of these embedded electrodes on the heat transport process, flow rate, and pressure in the micro-evaporator and on the two-phase loop system is characterized. Local enhancements are found to be up to 30% at low heat fluxes. The reverse effect that phase-change has on the EHD conduction pumping phenomenon is also quantified.
Flow Over a Stretching Sheet in a Dusty Fluid With Radiation Effect
Authors: Ramesh G. K. , Gireesha B. J.
Published: August 2013

The radiation effect on a steady two-dimensional boundary layer flow of a dusty fluid over a stretching sheet is analyzed. The governing nonlinear partial differential equations have been transformed by a similarity transformation into a system of nonlinear ordinary differential equations and then solved numerically by applying Runge Kutta Fehlberg fourth-fifth order method (RKF45 method). The effect of fluid particle interaction parameter, Prandtl number, Eckert number, and radiation parameter on heat transfer characteristics in two different general cases, namely (1) the prescribed surface temperature (PST) and (2) the prescribed heat flux (PHF) are presented graphically and discussed. The rate of heat transfer is computed and tabulated for various values of the different parameters. Comparison of the obtained numerical results is made with previously published results.
H

∞ Switched
Filtering for Networked Systems Based on Delay Occurrence Probabilities1
Authors: Zhang Hui , Shi Yang , Liu Mingxi
Published: August 2013

This paper considers the state estimation problem for discrete-time systems in a network environment. Specifically, the network-induced delay from the sensor node to the estimator node is modeled as a finite set of delays with corresponding occurrence probabilities. The design of H∞ switched filters is proposed. The switching is performed according to the detected time delay. The occurrence probability of the delay is incorporated into the filter design, which can improve the filtering performance. Simulation studies and comparisons illustrate the effectiveness and the improvement of the proposed design method.
Smart Glass and Its Potential in Energy Savings
Authors: Wong Kaufui V. , Chan Richard
Published: August 2013

Smart glass is such that its properties may be changed by application of a potential across it. The change in properties may be engineered to alter the amount of heat energy that can penetrate the glass which provides heating and cooling design options. Therein lies its potential in energy savings. Smart glass may be classified into three types: electrochromic, suspended particle, and polymer dispersed liquid crystal (PDLC). Each of these types has their own mechanisms, advantages, and disadvantages. Electrochromic smart glass is the most popular, currently it utilizes an electrochromic film with an ion storage layer and ion conductor placed between two transparent plates. The electrochromic film is usually made of tungsten oxide, owing to the electrochromic nature of transition metals. An electric potential initiates a redox reaction of the electrochromic film transitioning the color and the transparency of the smart glass. Suspended particle smart glass has needle shaped particles suspended within an organic gel placed between two electrodes. In its off state, the particles are randomly dispersed and have a low light transmittance. Once a voltage is applied, the needle particles will orient themselves to allow for light to pass through. PDLC smart glass works similarly to the suspended particle variety. However, in PDLC smart glass, the central layer is a liquid crystal placed within a polymer matrix between electrodes. Similar in behavior to the suspended particles, in the off position the liquid crystals are randomly dispersed and have low transmittance. With the application of a voltage, the liquid crystals orient themselves, thereby allowing for the transmittance of light. These different smart glasses have many different applications, but with one hindrance. The requirement of a voltage source is a major disadvantage which greatly complicates the overall installation and manufacturing processes. However, the integration of photovoltaic (PV) devices into smart glass technology has provided one solution. Photovoltaic films attached in the smart glass will provide the necessary voltage source. The photovoltaic film may even be designed to produce more voltage than needed. The use a photovoltaic smart glass system provides significant cost savings in regards to heating, cooling, lighting, and overall energy bills. Smart glass represents a technology with a great deal of potential to reduce energy demand. Action steps have been identified to propagate the popular use of smart glass.
Time-Resolved Two-Dimensional Temperature Measurement From Acetylene-Oxygen Flame Using Chemical Seeding Spectrocamera
Authors: Oyama Hiroyuki , Kayahana Joe , Yatsu Shigeo , Kitagawa Kuniyuki , Gupta Ashwani K.
Published: August 2013

Precise knowledge on temperature and its fluctuation in combustion systems are among the important energy issues in almost all industrial sectors, energy conversion and power fields. In this study, a spectroscopic technique is used to measure the time-resolved temperature distribution by a comparatively simple optical system that involved two band-pass filters (BPF), and a charge-coupled device with image intensifier (ICCD) video camera. The system was assembled and applied to an acetylene-oxygen premixed flame that are widely used for welding purposes because of very high temperature in such flames. The temperature distribution and its fluctuation directly impact the quality of soldering. The results provided direct visualization of temperature and its fluctuation in the flames that are conjectured to emanate from thermal and hydrodynamic phenomena from chemical reactions in the flame and interaction with surrounding air.
Influence of Tip Shape on Reynolds Number Sensitivity for a Seven Hole Pressure Probe
Authors: Crawford James , Michael Birk A.
Published: August 2013

The effects of tip shape on Reynolds number sensitivity of a seven hole pressure probe are studied over a range of flows associated with practical use of turbomachinery. It is shown that at low flow angles the response of a conical or hemispherical tipped probe is independent of a Reynolds number above Re = 3000, and at high flow angles Re = 6000. Despite there not being a discernible difference in the average error in flow properties at different Reynolds numbers between the two tip shapes, it is shown that the hemispherical tip is preferred because the pressure distributions around the tip are more consistent.
Characteristics of Flame Modes for a Conical Bluff Body Burner With a Central Fuel Jet
Authors: Tang Haojie , Yang Dong , Zhang Tongfeng , Zhu Min
Published: August 2013

Bluff body stabilized nonpremixed flames are usually used as pilot flames in lean-premixed combustors. Experiments are conducted to investigate the characteristics of the flame. Typical flame modes are investigated in both stable and unstable conditions. The flow structures, the reaction zone, and the dynamics of unstable flames are measured with particle image velocimetry (PIV), intensified charge-coupled device (ICCD) and a high-speed camera, respectively, based on which the inherent mechanisms that influence the configuration and stabilization of the flame are analyzed. Stable flames are apparently influenced by the mixing characteristics in the recirculation zone. Flame detachment, a typical phenomenon of stable flames in a turbulent air flow, can be explained by the distribution of fuel concentration in the recirculation zone. The Reynolds number of air has different effects on different parts of the flame, which results in three unstable flame modes at different Reynolds numbers of air. These results could be helpful for the design of stable burners in practice.
Inverted Brayton Cycle With Exhaust Gas Recirculation—A Numerical Investigation
Authors: Henke Martin , Monz Thomas , Aigner Manfred
Published: August 2013

Microgas turbine (MGT) based combined heat and power (CHP) units provide a highly efficient, low-pollutant technology to supply heat and electrical power from fossil and renewable energy sources; however, pressurized MGT systems in an electrical power range from 1 to 5 kWel utilize very small turbocharger components. These components suffer from higher losses, like seal and tip leakages, resulting in a reduced electrical efficiency. This drawback is avoided by an inverted Brayton cycle (IBC) based system. In an IBC hot gas is produced in a combustion chamber at atmospheric pressure. Subsequently, the exhaust gas is expanded in a turbine from an atmospheric to a subatmospheric pressure level. In order to increase electrical efficiency, heat from the turbine exhaust gas is recuperated to the combustion air. After recuperation, the gas is compressed to atmospheric pressure and is discharged from the cycle. To decrease the power demand of the compressor, and thereby increasing the electrical cycle efficiency, it is crucial to further extract residual thermal power from the gas before compression. Coolant flows provided by heating applications can use this heat supply combined with heat from the discharged exhaust gas. The low pressure levels of the IBC result in high volumetric gas flows, enabling the use of large, highly efficient turbocharger components. Because of this efficiency benefit and the described cooling demand, micro-CHP applications provide an ideal field for utilization of the IBC. To further increase the total efficiency, discharged exhaust gas can be partially recirculated to the air inlet of the cycle. In the present paper a steady state analysis of an IBC with exhaust gas recirculation (EGR) is shown, and compared to the performance of a conventional Brayton cycle with equivalent component properties. Using EGR, it could be found that the sensitivity of the electrical cycle efficiency to the coolant temperature further increases. The sequent discussion focuses on the trade-off between total efficiency and electrical efficiency, depending on coolant temperature and EGR rate. The results show that EGR can increase the total efficiency by 10% to 15% points, while electrical efficiency decreases by 0.5% to 1% point. If the coolant temperature is below 35 °C, condensation of water vapor in the exhaust gas leads to a further increase of heat recovery efficiency. A validated in-house simulation tool based on turbocharger maps has been used for the calculations.
Myocardial borders segmentation from cine MR images using bidirectional coupled parametric deformable models
Authors: Sliman Hisham , Khalifa Fahmi , Elnakib Ahmed , Soliman Ahmed , El‐Baz Ayman , Beache Garth M. , Elmaghraby Adel , Gimel'farb Georgy
Published: August 2013

Purpose:

The authors propose 3D (2D + time) novel, fast, robust, bidirectional coupled parametric deformable models that are capable of segmenting left ventricle (LV) wall borders using first‐ and second‐order visual appearance features. The authors examine the effect of the proposed segmentation method on the estimation of global cardiac performance indexes.

Methods:

First‐order visual appearance of the cine cardiac magnetic resonance (CMR) signals (inside and outside the boundary of the deformable model) is modeled with an adaptive linear combination of discrete Gaussians (LCDG). Second‐order visual appearance of the LV wall is accurately modeled with a translational and rotation‐invariant second‐order Markov–Gibbs random field (MGRF). The LCDG parameters are estimated using our previously proposed modification of the EM algorithm, and the potentials of rotationally invariant MGRF are computed analytically.

Results:

The authors tested the proposed segmentation approach on 15 cine CMR data sets using the Dice similarity coefficient (DSC) and the average distance (AD) between the ground truth and automated segmentation contours. The authors documented an average DSC value of 0.926 ± 0.022 and an average AD value of 2.16 ± 0.60 mm compared to two other level set methods that achieve an average DSC values of 0.904 ± 0.033 and 0.885 ± 0.02; and an average AD values of 2.86 ± 1.35 mm and 5.72 ± 4.70 mm, respectively.

Conclusions:

The proposed segmentation approach demonstrated superior performance over other methods. Specifically, the comparative results on the publicly available MICCAI 2009 Cardiac MR Left Ventricle Segmentation database documented superior performance of the proposed approach over published methods. Additionally, the high accuracy of our segmentation approach leads to accurate estimation of the global performance indexes, as evidenced by the Bland–Altman analyses of the end‐systolic volume (ESV), end‐diastolic volume (EDV), and the ejection fraction (EF) ratio.
Feasibility of kilovoltage x‐ray energy modulation by gaseous media and its application in contrast‐enhanced radiotherapy
Authors: Facundo‐Flores E. L. , Garnica‐Garza H. M.
Published: August 2013

Purpose:

To present a method to modulate the energy contents of a kilovoltage x‐ray beam that makes use of a gas as the modulating medium. The method is capable of producing arbitrary x‐ray spectra by varying the pressure of the modulating gas and the peak kilovoltage (kVp) of the x‐ray beams whose energy is being modulated.

Methods:

An aluminum chamber was machined with a 0.5 cm wall thickness, designed to withstand pressures of more than 80 atm. A pressure sensor and electrovalves were used to monitor and regulate the gas pressure. Argon was used as the modulating gas. A CdTe spectrometer was used to measure x‐ray spectra for different combinations of kVp and gas pressure, thus obtaining a set of basis x‐ray functions. An arbitrary x‐ray spectrum can then be formed by the linear combination of such basis functions. In order to show one possible application of the modulation method, a contrast‐enhanced radiotherapy prostate treatment was optimized with respect to the x‐ray beam energy, without restrictions on the possible shape of the resultant x‐ray spectra.

Results:

The x‐ray spectra basis functions obtained display a smooth and gradual variation of their average energy as a function of the gas pressure for a given kVp, sometimes in the order of 1 or 2 keV. This gradual variation would be difficult to obtain with a conventional aluminum or copper filters, as the change in thickness necessary to reproduce the data presented would be in the order of micrometers, making necessary the use of a large number of such filters. Using the modulation method presented here, the authors were able to reconstruct the optimized x‐ray spectra from the measured basis functions, for different optimization objectives.

Conclusions:

A method has been developed that allows for the controlled modulation of the energy contents of kilovoltage x‐ray spectra. The method has been shown to be able to reproduce spectra of arbitrary shape, such as those obtained from the optimization of contrast‐enhanced radiotherapy. The method may have other applications as well, such as in the precise matching of diagnostic x‐ray catalog spectra.
Geometric explanation of conic-section interference fringes in a Michelson interferometer
Authors: Fang Guangyu , Huang Li , Xin Li , Zhao Haifa , Huo Lei , Wu Lili
Published: August 2013

A simple geometric method based on wave-front analysis is developed to provide a concise explanation for the various interference fringes in a Michelson interferometer without the compensator plate. In view of the fact that a homocentric pencil of rays from a point light source becomes astigmatic as it passes obliquely through a glass plate, the wave-front deviation from a spherical one is obtained by calculating the astigmatic focal distance of the central ray. If the compensator plate is removed, the two central rays along the interfering paths have different astigmatic focal distances (AFDs), therefore, the optical path length difference can never be compensated with the movement of the reflected mirrors. The wave-front difference or the optical path difference is determined to the accuracy of second order by comparing the two pairs of principal curvature radii, and the trivial point-by-point calculation of the optical path length difference (OPD) is avoided. Numerical results support the theoretical analysis with great accuracy.
Response times to conceptual questions
Authors: Lasry Nathaniel , Watkins Jessica , Mazur Eric , Ibrahim Ahmed
Published: August 2013

We measured the time taken by students to respond to individual Force Concept Inventory (FCI) questions. We examine response time differences between correct and incorrect answers, both before and after instruction. We also determine the relation between response time and expressed confidence. Our data reveal three results of interest. First, response times are longer for incorrect answers than for correct ones, indicating that distractors are not automatic choices. Second, response times increase after instruction for both correct and incorrect answers, supporting the notion that instruction changes students' approach to conceptual questions. Third, response times are inversely related to students' expressed confidence; the lower their confidence, the longer it takes to respond.
How to model connection wires in a circuit: From physical vector fields to circuit scalar quantities
Authors: Vandenbosch Guy A. E.
Published: August 2013

Starting from the basic equations of electromagnetism, Maxwell's equations, the concepts of inductive coupling in a loop and capacitive coupling between two pieces of wire are formally explained. Inductive coupling is linked to Faraday's law and capacitive coupling to the Ampere-Maxwell law. Capacitive coupling is also inherently linked to the phenomenon of surface charges, which has been recently studied thoroughly in the literature, especially in static situations. It is shown that, when applied to the connecting wires in a circuit at higher frequencies, simple circuit theory must be significantly modified in order to take into account the effects of the two types of coupling between the wires.
A cost-efficient frequency-domain photoacoustic imaging system
Authors: LeBoulluec Peter , Liu Hanli , Yuan Baohong
Published: August 2013

Photoacoustic (PA) imaging techniques have recently attracted much attention and can be used for noninvasive imaging of biological tissues. Most PA imaging systems in research laboratories use the time domain method with expensive nanosecond pulsed lasers that are not affordable for most educational laboratories. Using an intensity modulated light source to excite PA signals is an alternative technique, known as the frequency domain method, with a much lower cost. In this paper, we describe a simple frequency domain PA system and demonstrate its imaging capability. The system provides opportunities not only to observe PA signals in tissue phantoms but also to acquire hands-on skills in PA signal detection. It also provides opportunities to explore the underlying mechanisms of the PA effect.
Seeing an Old Lab in a New Light: Transforming a Traditional Optics Lab into Full Guided Inquiry
Authors: Maley Tim , Stoll Will , Demir Kadir
Published: August 2013

This paper describes the authors' experiences transforming a “cookbook” lab into an inquiry-based investigation and the powerful effect the inquiry-oriented lab had on our students' understanding of lenses. We found the inquiry-oriented approach led to richer interactions between students as well as a deeper conceptual understanding of how images are formed. We observed engaged students participating in scientific discourse full of hypothesizing, modeling, and argumentation based on evidence.
Susac's syndrome: an immune mediated endotheliopathy laden with challenges and controversies
Authors: Malhotra Abhishek , Reyneke Elizabeth , Needham Merrilee
Published: August 2013

Susac's syndrome is a microangiopathy of the retina, inner ear and brain manifesting as a triad of encephalopathy, hearing loss and branch retinal artery occlusion. The pathological mechanism is thought to be an immune-mediated small vessel vasculitis with some pathophysiological similarity to dermatomyositis. Awareness and early recognition of this syndrome is important as early treatment with immunosuppression can minimise cognitive, audiological and visual sequelae. We report a case of a 33-year-old woman who presented with the characteristic syndrome. She was treated with immunomodulatory therapy and remains well 2 years postpresentation with no new events.
Renal denervation in fibromuscular dysplasia
Authors: Kelle Sebastian , Teller Desiree Claudia , Fleck Eckart , Stawowy Philipp
Published: August 2013

Renal denervation offers novel treatment opportunities in patients with resistant hypertension, including cases with rare causes (fibromuscular dysplasia), warranting further investigation.
Sustained antidepressant response to ketamine
Authors: Atigari Onome Victor , Healy David
Published: August 2013

Case series outlining the treatment of three patients with ketamine, in which two of the patients had a sustained antidepressant effect to ketamine without the need for maintenance on antidepressants. These two responders have an established diagnosis of bipolar affective disorder with a history of response to electroconvulsive therapy and lithium, both of which have an influence on the seizure threshold as has ketamine. The mechanism of action of ketamine is yet unclear and although the current focus is on theN-methyl-d-aspartate and alpha-amino-3-4-hydroxy-5methyl-4-isoxazoleproprionic acid receptors, we additionally recommend that its impact on the seizure threshold should be explored with a view to fully elucidating the mechanism of action.