bluuebunny/crossref_metadata_2025 huggingface dataset:
That's the spirit: exploring the approach of the world's leading spirits' producers to corporate social responsibility
Authors: Jones Peter , Hillier David , Comfort Daphne
Published: September 2011

The aims of this paper are to provide an exploratory review of both the corporate social responsibility (CSR) agenda being publicly reported by the world's leading spirits' producers and the nature of their reporting CSR processes and to offer some wider reflections on the ways these producers are addressing and pursuing CSR strategies. The paper begins with a short discussion of the characteristics of CSR. It draws its empirical material from the most recent CSR reports posted on the Internet by the world's top 10 spirits' producers. The findings reveal that the leading spirits producers are moving towards integrating CSR into their core business; and while they particularly emphasise their commitment to promote responsible drinking, they also address a wide range of impacts within the marketplace, the communities in which they operate, the environment and the workplace. Although the leading spirits producers generally adopt a positive stance in their CSR reports, the independent external assessment of the reporting process is limited. More generally, the paper offers some critical reflections on the CSR agenda currently being by pursued by the leading spirits' producers. The paper provides an overview and some reflections on the CSR agenda being pursued by some of the world's leading spirits' producers; and as such, it will interest academics in business and management and hospitality departments, a range of people working in management positions within the drinks industry and those professionals who work with the industry. Copyright © 2011 John Wiley & Sons, Ltd.
Kalopanaxsaponins A and B Isolated from Kalopanax pictus Ameliorate Memory Deficits in Mice
Authors: Joh Eun‐Ha , Lee In‐Ah , Kim Dong‐Hyun
Published: September 2011

The stem‐bark of Kalopanax pictus (KP, family Araliaceae), which contains triterpenoid saponins, has been shown to exhibit anticarcinogenic, antiinflammatory, antirheumatoid and antidiabetic activities. In a preliminary study, a KP methanol extract demonstrated acetylcholinesterase activity in vitro and memory enhancement in scopolamine‐treated mice. Therefore, we isolated acetylcholinesterase inhibitors, kalopanaxsaponins A and B, from a KP butanol (BuOH) fraction, measured acetylcholinesterase activity in vitro, and investigated their memory‐enhancing effects in a passive avoidance test, Y‐maze test and Morris water maze test. These constituents inhibited acetylcholinesterase activity and significantly reversed scopolamine‐induced deficits. They also increased brain‐derived neurotrophic factor (BDNF) and phosphorylated cAMP response element binding (p‐CREB) protein expression but reduced TNF‐α increased by scopolamine. Based on these findings, kalopanaxsaponins A and B may ameliorate memory deficits by inhibiting acetylcholinesterase activity and inducing BDNF and p‐CREB expression. Copyright © 2011 John Wiley & Sons, Ltd.
Determination of elemental composition of volatile organic compounds from Chinese rose oil by spectral accuracy and mass accuracy
Authors: Zhou Wei , Zhang Yaheng , Xu Hongliang , Gu Ming
Published: September 2011

Elemental composition determination of volatile organic compounds through high mass accuracy and isotope pattern matching could not be routinely achieved with a unit‐mass resolution mass spectrometer until the recent development of the comprehensive instrument line‐shape calibration technology. Through this unique technology, both m/z values and mass spectral peak shapes are calibrated simultaneously. Of fundamental importance is that calibrated mass spectra have symmetric and mathematically known peak shapes, which makes it possible to deconvolute overlapped monoisotopes and their 13C‐isotope peaks and achieve accurate mass measurements. The key experimental requirements for the measurements are to acquire true raw data in a profile or continuum mode with the acquisition threshold set to zero. A total of 13 ions from Chinese rose oil were analyzed with internal calibration. Most of the ions produced high mass accuracy of better than 5 mDa and high spectral accuracy of better than 99%. These results allow five tested ions to be identified with unique elemental compositions and the other eight ions to be determined as a top match from multiple candidates based on spectral accuracy. One of them, a coeluted component (Nerol) with m/z 154, could not be identified by conventional GC/MS (gas chromatography/mass spectrometry) and library search. Such effective determination for elemental compositions of the volatile organic compounds with a unit‐mass resolution quadrupole system is obviously attributed to the significant improvement of mass accuracy. More importantly, high spectral accuracy available through the instrument line‐shape calibration enables highly accurate isotope pattern recognition for unknown identification. Copyright © 2011 John Wiley & Sons, Ltd.
Faculty and first‐generation college students: Bridging the classroom gap together
Authors: Wiggins Janice
Published: September 2011

Drawing on her thirteen years of experience as director of Indiana University‐Bloomington's Groups Program, which serves first‐generation and low‐income students, the author details the challenges facing first‐generation college students (FGS). She argues for the need for sourcebooks such as this one to educate higher‐education personnel about the academic, cultural, and social experiences of FGS. Educating college and university personnel is the first step toward improving FGS' college success, retention, and graduation rates.
Introduction: Shall we gather in the classroom?
Authors: Housel Teresa Heinz , Harvey Vickie L.
Published: September 2011

First‐generation college students (FGS) often straddle different cultures between school and home. Because of this cultural disparity, FGS frequently encounter barriers to academic success and require additional support resources on campus. Simply offering more financial aid does not address the cultural and emotional challenges that these students experience. The volume's coeditors draw on their own first‐generation college experiences to assert the necessity of this volume to assist college and university administrators, faculty, and staff who frequently work with FGS.
First‐generation Latina graduate students: Balancing professional identity development with traditional family roles
Authors: Leyva Valerie Lester
Published: September 2011

The author discusses the little‐examined tensions that female and Latina first‐generation college students (FGS) experience while negotiating their ethnic and professional identities. Despite having general parental support for pursuing an education, Latina and female FGS who are graduate students in the author's university department must juggle multiple identities of gender role expectations with being students, family members, and parents.
Understanding the first‐generation student experience in higher education through a relational dialectic perspective
Authors: Lowery‐Hart Russell , Pacheco George
Published: September 2011

The authors use relational dialectics theory to argue that first‐generation college students (FGS) often struggle with a give‐and‐take tension between getting involved in campus life and losing their familial and working‐class identity. They suggest that because FGS straddle two different cultures of academia and home, institutions must address these tensions to improve the students' retention and graduate rates.
First‐generation issues: Learning outcomes of the dismissal testimonial for academically dismissed students in the arts & sciences
Authors: Brost Jennifer , Payne Kelly
Published: September 2011

The authors found that the experience of academic dismissal for first‐generation college students (FGS) differs from that of non‐FGS in that the FGS cited wrong course choices, inability to examine personal strengths and weaknesses, and not seeking academic help as reasons for dismissal. FGS who appealed the institution's dismissal decision indicated that if permitted to re‐enroll, they would become more involved in campus and seek faculty contact; these behaviors, the authors suggest, are crucial for the students' academic success.
Alzheimer's Disease and Co-Morbidity: Increased Prevalence and Possible Risk Factors of Excess Mortality in a Naturalistic 7-Year Follow-Up
Authors: Heun R. , Schoepf D. , Potluri R. , Natalwala A.
Published: September 2011

Background

Subjects with late-onset Alzheimer's disease (AD) have to be sufficiently healthy to live long enough to experience and to be diagnosed with dementia in later life. In contrast, neurodegeneration and cognitive deficits in AD may increase the frequency of co-morbid disorders and their possible influence on mortality. Consequently, we investigated whether the pattern of co-morbidity and its relevance for later death differed between hospitalized AD and age-matched controls subjects.

Methods

Co-morbid diseases with a prevalence of more than 1% at hospital admission were compared between 634 hospitalized AD and 72,244 control subjects aged above 70 years admitted to the University of Birmingham NHS Trust between 1 January 2000 to 31 December 2007. Risk factors, i.e. co-morbid diseases that were predictors of mortality within the 7-year follow-up, were identified and compared.

Results

Subjects with AD suffer more eating disorders, infections, brain diseases and neck of femur fractures than other hospitalized elderly patients. In contrast, some cardiovascular diseases and diabetes mellitus were less prevalent in AD subjects in comparison with hospitalized controls. Diseases that might have contributed to later mortality in AD were pneumonia, ischemic heart disease and gastroenteritis, but there were no significant differences in their impact on mortality compared to other hospitalized elderly subjects with the same co-morbidities in multivariate logistic regression analyses.

Conclusion

Patients with AD have a different pattern of co-morbidity, but die from the same diseases as other hospitalized patients. Infections including pneumonia and diseases that may occur secondary to neurodegeneration and cognitive decline may need special attention in patients with AD who may not be able to identify or report the early symptoms. Preventive measures may be helpful to reduce the high risk and fatal consequences of undetected disease in AD.
The interaction of round synthetic jets with a turbulent boundary layer separating from a rounded ramp
Authors: Lardeau S. , Leschziner M. A.
Published: September 2011

A computational large eddy simulation (LES) study is presented of the interaction between a turbulent boundary layer separating from a rounded ramp in a duct and a pair of spanwise-periodic, round synthetic jets, actuated upstream of the nominal separation line. Several scenarios are considered, for different injection angles and velocity ratios. In all cases, the actuation frequency corresponds to the shedding-instability mode of the separated shear layer. Experimental data, available for both the baseline flow and one actuated configuration, are used to verify the validity of the computational solutions. The analysis includes a separation of coherent and stochastic contributions to the time-averaged statistics of the auto- and cross-correlations of the fluctuations. The control authority is examined by reference to the effects of the actuation on the size of the separated zone, the momentum thickness of the boundary layer, the velocity field, various turbulence quantities and phase-averaged properties. The study demonstrates that the principal aspect of the interaction, at mean-flow level, is an increase in mixing provoked by the formation of strong streamwise vortices away from the wall, the induction of much weaker streamwise vortices close to the wall, and the extra production of stochastic turbulence caused by unsteady straining. The coherent stresses arising from the periodic perturbations are high – typically 5 times the levels of the unperturbed flow – but only within about 5–7 diameters of the jet orifice, and 2 orifice diameters on each side of the jet, and these are dominant primarily in the outer parts of the boundary layer. Stochastic turbulence is also elevated, but more modestly. The global effect of the actuation is a reduction of 10–20 % in the length of the separated region and 20–40 % in the thickness of the reverse-flow layer, depending on the actuation scheme, counter-flow actuation being the most effective. This reduction is mainly associated with a delay in separation. These results highlight the need for synthetic jets to be placed close to the separation zone and for the inter-jet distance to be of order 5 or lower to achieve a high level of separation-control authority.
Transitional flow of a rarefied gas over a spinning sphere
Authors: Volkov Alexey N.
Published: September 2011

Three-dimensional transitional flow of a rarefied monatomic gas over a spinning sphere is studied numerically by the direct simulation Monte Carlo method. Gas molecules interact with each other as hard spheres. The Maxwell model of specular–diffuse scattering is used to describe the interaction between gas molecules and the sphere surface. The effect of all dimensionless governing parameters of the problem on the flow structure, distributions of stresses and heat flux density on the sphere surface, aerodynamic force and torque exerted on the sphere, and heat flux on the sphere surface is analysed. Simulations are conducted at Mach numbers raging from$0. 03$to$2$and Knudsen numbers raging from$0. 01$to$20$. Two qualitatively different streamline patterns are observed around the sphere depending on its dimensionless rotational velocity. The direction and magnitude of the transverse Magnus force in transitional flow depend on the Knudsen and Mach numbers. The torque and heat flux coefficients are found to be functions of the Mach number and dimensionless rotational velocity. The effect of rotation on the sphere aerodynamics weakens with an increase in the sphere temperature with respect to the gas temperature in the free stream. A complete set of equations is developed to fit the computed values of the aerodynamic and heat flux coefficients in a case when the sphere temperature is equal to the temperature of the free stream.
Equol production changes over time in pre-menopausal women
Authors: Franke Adrian A. , Lai Jennifer F. , Pagano Ian , Morimoto Yukiko , Maskarinec Gertraud
Published: September 2011

Equol (EQ) is a metabolite produced by gut bacteria through the chemical reduction of the soya isoflavone daidzein (DE), but only by 30–60 % of the population. EQ is believed to provide benefits derived from soya intake and its production is widely viewed as a relatively stable phenomenon. In a randomised, cross-over intervention with soya foods, seventy-nine pre-menopausal women were challenged with a high-soya and a low-soya diet each for 6 months, separated by a 1-month washout period. Overnight urine was collected at three time points during each diet period and analysed for DE and EQ by liquid chromatography tandem MS. Remaining an EQ producer (EP) or non-producer (NP) or changing towards an EP or NP was assessed using an EQ:DE ratio of ≥ 0·018 combined with a DE threshold of ≥ 2 nmol/mg creatinine as a cut-off point. We observed 19 and 24 % EP during the low-soya and high-soya diet periods, respectively, and found that 6–11 % of our subjects changed EQ status ‘within’ each study period (on an average of 1·2 times), while 16 % changed ‘between’ the two diet periods. The present finding challenges the widely held conviction that EQ production within an individual remains stable over time. The precise factors contributing to changes in EQ status, however, remain elusive and warrant further investigation.
Pharmacokinetics of fucoxanthinol in human plasma after the oral administration of kombu extract
Authors: Hashimoto Takashi , Ozaki Yoshiaki , Mizuno Masashi , Yoshida Masaru , Nishitani Yosuke , Azuma Takeshi , Komoto Akitoshi , Maoka Takashi , Tanino Yuka , Kanazawa Kazuki
Published: September 2011

Dietary fucoxanthin has been reported to exert several physiological functions, and fucoxanthinol is considered to be the primary active metabolite of fucoxanthin. However, there is no information about the pharmacokinetics of fucoxanthinol in human subjects. In the present study, eighteen human volunteers were orally administered kombu extract containing 31 mg fucoxanthin, and their peripheral blood was collected 5 min before and 0·5, 1, 2, 4, 8 and 24 h after the treatment. Plasma fucoxanthinol concentrations were measured by HPLC, and the pharmacokinetics of fucoxanthinol were as follows: maximum concentration, 44·2 nmol/l; time at maximum concentration, 4 h; terminal half-time, 7·0 h; area under the curve (AUC) for 1–24 h, 578·7 nmol/l × h; AUC(∞), 663·7 nmol/l × h. In addition to fucoxanthinol, we also attempted to detect amarouciaxanthin A, a hepatic metabolite of fucoxanthinol, using HPLC, but it was not present in the volunteers' plasma. On the other hand, a peak that was suspected to represent the cis-isomer of fucoxanthinol was found in the HPLC chromatogram. By comparing the present results with those of a previous study using mice, we found that the bioavailability and metabolism of fucoxanthinol differ between human subjects and mice.
Group actions on topological graphs
Authors: DEACONU VALENTIN , KUMJIAN ALEX , QUIGG JOHN
Published: September 2011

We define the action of a locally compact groupGon a topological graphE. This action induces a natural action ofGon theC*-correspondence ℋ(E) and on the graphC*-algebraC*(E). If the action is free and proper, we prove thatC*(E)⋊rGis strongly Morita equivalent toC*(E/G) . We define the skew product of a locally compact groupGby a topological graphEvia a cocyclec:E1→G. The group acts freely and properly on this new topological graphE×cG. IfGis abelian, there is a dual action onC*(E) such that$C^*(E)\rtimes \hat {G}\cong C^*(E\times _cG)$. We also define the fundamental group and the universal covering of a topological graph.
Path Dependence and the Modernisation of Agriculture: A Case Study of Aragon, 1955–85
Authors: CLAR ERNESTO , PINILLA VICENTE
Published: September 2011

This paper explains how technological developments and changes in production encouraged and drove the processes of agricultural modernisation that occurred in the second half of the twentieth century, taking the region of Aragon in north eastern Spain as a case study. The main agricultural macro-variables reveal a surge in output, coincident with a far-reaching restructuring of production, in which livestock and animal feeds played a key role. The relative success of this high speed agricultural transformation was largely due to technological progress and the development of Aragon's trade links before 1936. Meanwhile, the earlier development of irrigation schemes, the capitalisation of farms and experimentation with different seed varieties allowed the region to adapt quickly to the new Green Revolution technologies that came to the fore after 1950. At the same time, established trade links allowed a swift transition to livestock and related produce destined for fast developing agro-industrial regions, like Catalonia and Valencia. As in other countries, technological and trade path dependency also explain the polarisation of agricultural development within Aragon itself, and in particular the success of the provinces of Zaragoza and Huesca in contrast to failure and depopulation in Teruel. The experience of Aragon may thus be useful to understand the dynamics of other less developed regions currently in the throes of transformation.
Working on word-processed French
Authors: Dayan Peter
Published: September 2011

In October 1992, I was awarded funding by the Edinburgh University Enterprise Centre for a ninemonth project entitled ‘The Development of Self-Directed Learning using Computers and Satellite TV’. The aim of the ‘computers’ half of the project was to find ways of getting first-year students to spend more time working by themselves on the quality of their written French.
Towards user/system collaboration in developing a student model for intelligent computer assisted language learning
Authors: Bull Susan
Published: September 2011

This paper examines research in the field of collaborative learning, concentrating on aspects suitable for use in an intelligent computer assisted language learning (ICALL) system. Current work on the project focuses on the construction of a student model, based on the notion that a model constructed and repaired through collaboration between the system and student will lead to a more accurate representation of the learner's beliefs, and is less likely to be regarded with suspicion by the student. Further, the act of collaboration should promote reflection on both the language to be learnt and the student's approaches to learning.
Computer-assisted vocabulary acquisition: an evaluation of the text analysis program
Authors: McKee Jane
Published: September 2011

The Text Analysis Program (TAP) was designed by a team from the Department of European Studies and Modern Languages and the Computer Services Department of the University of Ulster with a view to enhancing language learning techniques for third level language students. Work on the program was funded jointly by the CTI and the University of Ulster. A Multiple Choice Question (MCQ) program was also developed as part of the same project. The program came into service in the academic year 1989-90 when it was tested on three groups of students. Some minor modifications were made before it was reused in 1990-91 and 1991-92 with the group of students who seemed to us most likely to benefit from its use. It is now undergoing further adjustment in the light of the second and third year's experience and is set to become a permanent feature of second year teaching on the BA (Hons) International Business Communication course (IBC). The present paper seeks to evaluate the program under two headings: ease of use and effectiveness as a means of enhancing linguistic awareness and language learning techniques.
Environmental standard and employment: impact of productivity effect
Authors: Sen Anindita , Acharyya Rajat
Published: September 2011

This paper analyses the effect of environmental standards on aggregate employment in the presence of a productivity effect in a multi-sector general equilibrium framework of an open economy. The productivity effect is generated among the skilled and unskilled workers as an improvement in the environmental quality improves their health, leading to an increase in their productivity. Though the productivity effect initially lowers labour demand as labour requirement per unit of production falls, a standard may raise employment depending on the parametric configurations. In this paper, we identify the role of this productivity effect on the change in employment and show that it may actually improve the chances of an employment expansion.
The Psychometric Properties of the DS14 in Hebrew and the Prevalence of Type D Personality in Israeli Adults
Authors: Zohar Ada H. , Denollet Johan , Lev Ari Lilac , Cloninger C. Robert
Published: September 2011

Objectives: To examine the psychometric properties of the 14-item Type D Scale (DS14) in Hebrew, and to estimate the prevalence of Type D personality (high negative affectivity and social inhibition) in Israeli adults. Methods: 1,350 consecutive community volunteers were recruited and completed questionnaires that included the DS14, the 140-item Temperament and Character Inventory (TCI-140), the Toronto Alexithymia Scale-20 (TAS-20), the Positive and Negative Affect Scale (PANAS), social support, well-being, assessment of smoking behavior, physical and sexual activity, known medical diagnoses, and family history of coronary heart disease (CHD). Results: The structural validity, as demonstrated by exploratory and confirmatory factor analysis, and the internal reliability of the DS14 was acceptable. Overall prevalence of Type D was 24.1%; individuals of Type D versus non-D were significantly higher in self-reported rates of hypertension, CHD diagnosis, and first-degree relatives diagnosed with CHD. They were also elevated for TCI-140 Harm Avoidance, as well as negative affect, alexithymia, and significantly lower in TCI-140 Novelty Seeking, Reward Dependence, Persistence, Self-Directedness, and Cooperativeness, as well as in subjective well-being, social support, and positive affect. Conclusion: The DS14 in Hebrew has good psychometric qualities, supporting cross-cultural validity.
The Impact of Group Entitativity on Linguistic Discrimination
Authors: Moscatelli Silvia , Rubini Monica
Published: September 2011

This study investigated the impact of minimal group entitativity on linguistic ingroup favoritism and outgroup derogation. Group entitativity varied across three conditions: mere categorization, spatial separation of groups, and common fate. Participants described with spontaneous language negative outcome allocations performed either by ingroup or by outgroup members. Findings showed that linguistic discrimination was not elicited by mere categorization and occurred only in the common fate condition. Group entitativity mainly affected linguistic outgroup derogation. This study adds to the evidence of linguistic discrimination in minimal groups and shows the strength of a linguistic measure in disentangling the different components of intergroup bias.
Platelet Mitochondrial Dysfunction is Evident in Type 2 Diabetes in Association with Modifications of Mitochondrial Anti-Oxidant Stress Proteins
Authors: Avila C. , Huang R. , Stevens M. , Aponte A. , Tripodi D. , Kim K. , Sack M.
Published: September 2011

Mitochondrial dysfunction and oxidative stress in insulin responsive tissues is implicated in the pathogenesis of type 2 diabetes. Whether these perturbations extend to other tissues and contribute to their pathophysiology is less well established. The objective of this study was to investigate platelet mitochondria to evaluate whether type 2 diabetes associated mitochondrial dysfunction is evident in circulating cells.

A pilot study of mitochondrial respiratory function and proteomic changes comparing platelets extracted from insulin sensitive (n=8) and type 2 diabetic subjects (n=7).

In-situ platelet mitochondria show diminished oxygen consumption and lower oxygen-dependent ATP synthesis in diabetic vs. control subjects. Mass spectrometric identification and confirmatory immunoblot analysis identifies induction of the mitochondrial anti-oxidant enzymes superoxide dismutase 2 and thioredoxin-dependent peroxide reductase 3 in platelets of diabetic subjects. As oxidative stress upregulates anti-oxidant enzymes we assessed mitochondrial protein carbonylation as an index of oxidative-stress. Platelets of diabetic subjects exhibit significantly increased protein carbonylation compared to controls.

As platelets are anuclear fragments of megakaryocytes, our data suggest that the bone marrow compartment in type 2 diabetic subjects is exposed to increased mitochondrial oxidative stress with upregulation of nuclear-encoded antioxidant mitochondrial enzymes. This ‘stress-signature’ in platelets of diabetic subjects is associated with a diminution of their mitochondrial contribution to energy production and support that mitochondrial perturbations in type 2 diabetes extends beyond the classical insulin responsive tissues. Platelets, as “accessible human tissue”, may be useful to measure the mitochondrial modulatory effects of emerging anti-diabetic therapeutics.
Simulations reveal fast mode shocks in magnetic reconnection outflows
Authors: Workman Jared C. , Blackman Eric G. , Ren Chuang
Published: September 2011

Magnetic reconnection is commonly perceived to drive flow and particle acceleration in flares of solar, stellar, and astrophysical disk coronae but the relative roles of different acceleration mechanisms in a given reconnection environment are not well understood. While outflow fast mode shocks have been predicted analytically, we show for the first time via direct numerical simulations that such shocks do indeed occur in the outflows of fast reconnection when an obstacle is present. These shocks are distinct from the slow mode Petschek inflow shocks. If Fermi acceleration of electrons operates in the weak fast shocks, the associated compression ratios will induce a Fermi acceleration particle spectrum that is significantly steeper than strong fast shocks commonly studied, but consistent with the demands of solar flares. While this is not the only acceleration mechanism operating in a reconnection environment, it is plausibly a ubiquitous one.
Comparison between pulsed laser and frequency-domain photoacoustic modalities: Signal-to-noise ratio, contrast, resolution, and maximum depth detectivity
Authors: Lashkari Bahman , Mandelis Andreas
Published: September 2011

In this work, a detailed theoretical and experimental comparison between various key parameters of the pulsed and frequency-domain (FD) photoacoustic (PA) imaging modalities is developed. The signal-to-noise ratios (SNRs) of these methods are theoretically calculated in terms of transducer bandwidth, PA signal generation physics, and laser pulse or chirp parameters. Large differences between maximum (peak) SNRs were predicted. However, it is shown that in practice the SNR differences are much smaller. Typical experimental SNRs were 23.2 dB and 26.1 dB for FD-PA and time-domain (TD)-PA peak responses, respectively, from a subsurface black absorber. The SNR of the pulsed PA can be significantly improved with proper high-pass filtering of the signal, which minimizes but does not eliminate baseline oscillations. On the other hand, the SNR of the FD method can be enhanced substantially by increasing laser power and decreasing chirp duration (exposure) correspondingly, so as to remain within the maximum permissible exposure guidelines. The SNR crossover chirp duration is calculated as a function of transducer bandwidth and the conditions yielding higher SNR for the FD mode are established. Furthermore, it was demonstrated that the FD axial resolution is affected by both signal amplitude and limited chirp bandwidth. The axial resolution of the pulse is, in principle, superior due to its larger bandwidth; however, the bipolar shape of the signal is a drawback in this regard. Along with the absence of baseline oscillation in cross-correlation FD-PA, the FD phase signal can be combined with the amplitude signal to yield better axial resolution than pulsed PA, and without artifacts. The contrast of both methods is compared both in depth-wise (delay-time) and fixed delay time images. It was shown that the FD method possesses higher contrast, even after contrast enhancement of the pulsed response through filtering.
Nanoscale dynamic inhomogeneities in electroluminescence of conjugated polymers
Authors: Hatano Tatsuhiko , Nozue Shuho , Habuchi Satoshi , Vacha Martin
Published: September 2011

We report the observation and characterization of dynamic spatial heterogeneities in the electroluminescence (EL) of conjugated polymer organic light-emitting diodes via high-sensitivity fluorescence microscopy. The active layers of the single-layer devices are polymers of the poly(phenylene vinylene) family, i.e., poly[2-methoxy, 5-(2′-ethyl-hexyloxy)-p-phenylene vinylene] and a commercially available copolymer, Super Yellow. The devices are prepared directly on a microscope coverslip, making it possible to use high numerical aperture oil-immersion objective lenses with a diffraction-limited resolution of a few hundred nanometers for microscopic EL imaging. Detection via high-sensitivity CCD camera allows the measurement of EL dynamics with millisecond time resolution for a wide range of applied voltages. We found spatial heterogeneities in the form of high EL intensity sites in all devices studied. The EL from these sites is strongly fluctuating in time, and the dynamics is bias voltage dependent. At the same time, there is no difference in the local microscopic EL spectra between the high- and low-intensity sites. The results are interpreted in terms of a changing charge balance and local structural changes in the active film layer.
The effects of inhomogeneous boundary dilution on the coating flow of an anti-HIV microbicide vehicle
Authors: Tasoglu Savas , Peters Jennifer J. , Park Su Chan , Verguet Stéphane , Katz David F. , Szeri Andrew J.
Published: September 2011

A recent study in South Africa has confirmed, for the first time, that a vaginal gel formulation of the antiretroviral drug Tenofovir, when topically applied, significantly inhibits sexual HIV transmission to women [Karim et al., Science 329, 1168 (2010)]. However, the gel for this drug and anti-HIV microbicide gels in general have not been designed using an understanding of how gel spreading and retention in the vagina govern successful drug delivery. Elastohydrodynamic lubrication theory can be applied to model spreading of microbicide gels [Szeri et al., Phys. Fluids 20, 083101 (2008)]. This should incorporate the full rheological behavior of a gel, including how rheological properties change due to contact with, and dilution by, ambient vaginal fluids. Here, we extend our initial analysis, incorporating the effects of gel dilution due to contact with vaginal fluid produced at the gel-tissue interface. Our original model is supplemented with a convective-diffusive transport equation to characterize water transport into the gel and, thus, local gel dilution. The problem is solved using a multi-step scheme in a moving domain. The association between local dilution of gel and rheological properties is obtained experimentally, delineating the way constitutive parameters of a shear-thinning gel are modified by dilution. Results show that dilution accelerates the coating flow by creating a slippery region near the vaginal wall akin to a dilution boundary layer, especially if the boundary flux exceeds a certain value. On the other hand, if the diffusion coefficient of boundary fluid is increased, the slippery region diminishes in extent and the overall rate of gel spreading decreases.
Breakdown voltage of ultrathin dielectric film subject to electrostatic discharge stress
Authors: Jin Hao , Dong Shurong , Miao Meng , Jei Liou Juin , Yang Cary Y.
Published: September 2011

Ultrathin silicon oxide film for nano-electromechanical system (NEMS) applications is investigated under electrostatic discharge (ESD) stress using a transmission line pulse (TLP) tester. The measured breakdown voltage and transient response are analyzed. The results show that the voltage stress time has a significant effect on the breakdown voltage. By shortening the stress time, the breakdown voltage increases by 2–3 times. With the area shrinking breakdown voltage increases, and there is a critical value, below which the breakdown voltage increases dramatically with decreasing area. It is possible to enhance the ESD robustness by using a multiple small-area dielectric layer structure. Shorten ESD pulse rise-time induces a higher overshoot current and then accelerates oxide failure, resulting in a lower breakdown voltage for a faster pulse.
Pressure-induced phase transformations during femtosecond-laser doping of silicon
Authors: Smith Matthew J. , Lin Yu-Ting , Sher Meng-Ju , Winkler Mark T. , Mazur Eric , Gradečak Silvija
Published: September 2011

Silicon hyperdoped with chalcogens via femtosecond-laser irradiation exhibits unique near-unity sub-bandgap absorptance extending into the infrared region. The intense light-matter interactions that occur during femtosecond-laser doping produce pressure waves sufficient to induce phase transformations in silicon, resulting in the formation of metastable polymorphic phases, but their exact formation mechanism and influence on the doping process are still unknown. We report direct observations of these phases, describe their formation and distribution, and consider their potential impact on sub-bandgap absorptance. Specifically, the transformation from diamond cubic Si-I to pressure-induced polymorphic crystal structures (amorphous Si, Si-XII, and Si-III) during femtosecond-laser irradiation was investigated using scanning electron microscopy, Raman spectroscopy, and transmission electron microscopy. Amorphous Si, Si-XII, and Si-III were found to form in femtosecond-laser doped silicon regardless of the presence of a gaseous or thin-film dopant precursor. The rate of pressure loading and unloading induced by femtosecond-laser irradiation kinetically limits the formation of pressure-induced phases, producing regions of amorphous Si 20 to 200 nm in size and nanocrystals of Si-XII and Si-III. The surface texturing that occurs during femtosecond-laser irradiation produces inhomogeneous pressure distributions across the surface and causes delayed development of high-pressure silicon polymorphs over many laser pulses. Finally, we find that the polymorph phases disappear during annealing more rapidly than the sub-bandgap absorptance decreases, enabling us to decouple these two processes through post-treatment annealing.
Quantum and semiclassical theories for nonadiabatic transitions based on overlap integrals related to fast degrees of freedom
Authors: Fujii Mikiya
Published: September 2011

Alternative treatments of quantum and semiclassical theories for nonadiabatic dynamics are presented. These treatments require no derivative couplings and instead are based on overlap integrals between eigenstates corresponding to fast degrees of freedom, such as electronic states. Derived from mathematical transformations of the Schr\documentclass[12pt]{minimal}\begin{document}$\ddot{\rm o}$\end{document}ödinger equation, the theories describe nonlocal characteristics of nonadiabatic transitions. The idea that overlap integrals can be used for nonadiabatic transitions stems from an article by Johnson and Levine [Chem. Phys. Lett. 13, 168 (1972)]10.1016/0009-2614(72)80069-1. Furthermore, overlap integrals in path-integral form have been recently made available by Schmidt and Tully [J. Chem. Phys. 127, 094103 (2007)]10.1063/1.2757170 to analyze nonadiabatic effects in thermal equilibrium systems. The present paper expands this idea to dynamic problems presented in path-integral form that involve nonadiabatic semiclassical propagators. Applications to one-dimensional nonadiabatic transitions have provided excellent results, thereby verifying the procedure. In principle these theories that are presented can be applied to multidimensional systems, although numerical costs could be quite expensive.
Spectroscopic signature of strain-induced quantum dots created by buried InAs quantum dots in an InGaAs quantum well
Authors: Mazur Yu. I. , Dorogan V. G. , Marega E. , Tarasov G. G. , Salamo G. J.
Published: September 2011

Spectroscopic study of self-assembled InAs/GaAs quantum dots (QDs) capped with an InxGa1−xAs quantum well (QW) is carried out under variable excitation intensity and temperature. The QW reduces strain in the QDs, and it is demonstrated that the cap layer shifts the transition energy of the QD lower, while maintaining the strong quantization of the QD electronic states which develops in photoluminescence as a series of excited state transitions at higher excitation intensity. An additional spectral band is also revealed below the energy of the InGaAs QW exciton, which is unambiguously assigned to the emission of a strain-induced QD layer created by the InAs stressors within the InGaAs QW.
Distinguished self-adjoint extensions of Dirac operators via Hardy-Dirac inequalities
Authors: Arrizabalaga Naiara
Published: September 2011

We prove some Hardy-Dirac inequalities with two different weights including measure valued and Coulombic ones. Those inequalities are used to construct distinguished self-adjoint extensions of Dirac operators for a class of diagonal potentials related to the weights in the mentioned inequalities.
Electronic properties of vacancy related defects in ZnO induced by mechanical polishing
Authors: Quemener V. , Vines L. , Monakhov E. V. , Svensson B. G.
Published: September 2011

Electronic properties of defects induced by mechanical polishing in hydrothermally grown n-type ZnO have been investigated by capacitance versus voltage measurements and deep level transient spectroscopy (DLTS). The DLTS measurements have been performed in the temperature range 80-600 K enabling exploration of deep-level states in the vicinity of the middle of the energy bandgap. The results show that mechanical polishing forms defects in the near surface region which strongly compensate and/or passivate the dominant shallow donors. Two pronounced polishing-induced defects are revealed with energy level positions around 1.0 eV and 1.2 eV below the conduction band edge. These levels are assigned to vacancy-related defect centers and substantially reduced in strength by post-polishing etching in diluted hydrofluoric acid.
Remarkable enhancement in photocurrent of In0.20Ga0.80N photoanode by using an electrochemical surface treatment
Authors: Li Mingxue , Luo Wenjun , Liu Bin , Zhao Xin , Li Zhaosheng , Chen Dunjun , Yu Tao , Xie Zili , Zhang Rong , Zou Zhigang
Published: September 2011

The photocurrent and incident photon conversion efficiency of In0.20Ga0.80N increased about 2 times after a simple electrochemical surface treatment. X-ray photoelectron spectroscopy and photoluminescence analysis suggested that In-rich InGaN region on the surface of the In0.20Ga0.80N electrode was removed by using the electrochemical surface treatment. The enhancement of the photocurrent was attributed to the removal of In-rich InGaN phases caused by indium segregations on the surface of the electrode, which played a major role as surface recombination centers of photo-generated electron-hole pairs.
Photocatalytic Water Oxidation Using Manganese Compounds Immobilized in Nafion Polymer Membranes
Authors: Young Karin J. , Gao Yunlong , Brudvig Gary W.
Published: September 2011

Robust water oxidation catalysts using earth abundant metals are required as part of an overall scheme to convert sunlight into fuels. Here, we report the immobilization of [Mn4IVO5(terpy)4(H2O)2](ClO4)6 (terpy = 2,2′;6′,2′′-terpyridine), [Mn4O6(tacn)4](ClO4)4 (tacn = 1,4,7-triazacyclononane), and manganese dioxide nanoparticles in Nafion on fluorine-doped tin oxide conducting glass electrodes. The electrodes are illuminated with white light in the presence of an applied potential and the resulting photocurrent is assigned to the oxidation of solvent water. Photodecomposition of the tetrameric complexes results in a material that is more active for light-driven electrooxidation of water. The reactivity, wavelength dependence, and stability of the compounds in Nafion under illumination are discussed.
Functionalized Polymers as Receptors for Detection of Cells
Authors: Polreichova Miroslava , Latif Usman , Dickert Franz L.
Published: September 2011

Mass sensitive sensors were applied for fast and label-free detection of bio-analytes. Robust and miniaturized sensor devices were fabricated by combining bio-mimetic imprinted surfaces with quartz crystal microbalances for the analysis of yeast and bacteria cells. These sensors allow us to differentiate between different growing stages of yeast cells. Moreover, the viability of cells was detected by structuring quartz crystal microbalance electrodes like a grid. Artificial yeast cells were produced to pattern the recognition layer, giving reversible enrichment of the respective bio-analytes. This approach was followed to ensure the reproducibility of the identical sensitive material in each case, because the properties of each cell depend on its growth stage, which varies over time. The strategy was further applied to develop a sensitive system for Escherichia coli. Structuring of these materials by soft lithography allows differentiation between cell strains, e.g. E. coli (strain W & B) with a five-fold selectivity.
Organometallic Complexes for Non-linear Optics. 49.* Third-Order Non-linear Optical Spectral Dependence Studies of Arylalkynylruthenium Dendrimers
Authors: Samoc Marek , Corkery T. Christopher , McDonagh Andrew M. , Cifuentes Marie P. , Humphrey Mark G.
Published: September 2011

The cubic hyperpolarizabilities of 1,3,5-(trans-[RuCl(dppe)2(C≡CC6H4-4-C≡C)])3C6H3 (1), 1,3,5-(trans-[Ru(C≡CPh)(dppe)2(C≡CC6H4-4-C≡C)])3C6H3 (2), 1,3,5-(trans-[Ru(C≡CC6H4-4-NO2)(dppe)2(C≡CC6H4-4-C≡C)])3C6H3 (3), 1,3,5-{trans-[Ru(C≡C-3,5-(trans-[Ru(C≡CPh)(dppe)2(C≡CC6H4-4-C≡C)])2C6H3)(dppe)2(C≡CC6H4-4-C≡C)]}3C6H3 (4), and 1,3,5-{trans-[Ru(C≡C-3,5-(trans-[Ru(C≡CC6H4-4-NO2)(dppe)2(C≡CC6H4-4-C≡C)])2C6H3)(dppe)2(C≡CC6H4-4-C≡C)]}3C6H3 (5) have been assessed over the spectral range 520–1600 nm using the Z-scan technique and ~150 fs pulses. All complexes exhibit negative values of γreal (corresponding to self-defocusing behaviour) and significant positive values of γimag (corresponding to two-photon absorption) at short wavelengths (up to 1000 nm). The maximal values of γreal and γimag increase in magnitude on dendrimer generation increase (proceeding from 2 to 4 or 3 to 5). The open-aperture Z-scan results have been used to confirm and contrast the two-photon (2PA) and three-photon absorption (3PA) behaviour of 1–5, the data being consistent with the existence of 2PA at the short wavelength range, but with significant 3PA at longer wavelengths for 1–3 and 5, a record 3PA coefficient for an inorganic complex for 5 at 1180 nm, and appreciable 3PA at the telecommunications wavelength of 1300 nm.
Impact of defoliation severity on photosynthesis, carbon metabolism and transport gene expression in perennial ryegrass
Authors: Lee Julia M. , Sathish Puthigae , Donaghy Daniel J. , Roche John R.
Published: September 2011

Defoliation severity affects grass regrowth. The changes to biological processes affecting regrowth induced by severe defoliation are not fully understood, nor have they been investigated at a molecular level in field-grown plants. Field-grown perennial ryegrass (Lolium perenne L.) plants were defoliated to 20, 40 or 60 mm during winter. Throughout regrowth, transcript profiles of 17 genes involved in photosynthesis and carbon metabolism or transport were characterised in stubble and lamina tissue. Although defoliation to 20 mm reduced residual lamina area and stubble water-soluble carbohydrate reserves compared with plants defoliated to 40 or 60 mm, net herbage regrowth was not reduced. Transcript profiles indicated a potential compensatory mechanism that may have facilitated regrowth. At the one-leaf regrowth stage, plants defoliated to 20 mm had greater abundance of photosynthesis-related gene transcripts (rca, rbcS1, rbcS2, fba, fbp and fnr) and 20% greater stubble total nitrogen than plants defoliated to 60 mm. A greater capacity for photosynthesis in outer leaf sheaths may be one potential mechanism used by severely defoliated plants to compensate for the reduced residual lamina area; however, this premise requires further investigation.