bluuebunny/crossref_metadata_2025 huggingface dataset:
DELAYS AT SIGNALIZED INTERSECTIONS WITH EXHAUSTIVE TRAFFIC CONTROL
Authors: Boon M.A.A. , Adan I.J.B.F. , Winands E.M.M. , Down D.G.
Published: June 2012

In this paper, we study a traffic intersection with vehicle-actuated traffic signal control. Traffic lights stay green until all lanes within a group are emptied. Assuming general renewal arrival processes, we derive exact limiting distributions of the delays under heavy traffic (HT) conditions. Furthermore, we derive the light traffic (LT) limit of the mean delays for intersections with Poisson arrivals, and develop a heuristic adaptation of this limit to capture the LT behavior for other interarrival-time distributions. We combine the LT and HT results to develop closed-form approximations for the mean delays of vehicles in each lane. These closed-form approximations are quite accurate, very insightful, and simple to implement.
LIKELIHOOD RATIO AND HAZARD RATE ORDERINGS OF THE MAXIMA IN TWO MULTIPLE-OUTLIER GEOMETRIC SAMPLES
Authors: Du Baojun , Zhao Peng , Balakrishnan N.
Published: June 2012

In this paper, we study some stochastic comparisons of the maxima in two multiple-outlier geometric samples based on the likelihood ratio order, hazard rate order, and usual stochastic order. We establish a sufficient condition on parameter vectors for the likelihood ratio ordering to hold. For the special case whenn= 2, it is proved that thep-larger order between the two parameter vectors is equivalent to the hazard rate order as well as usual stochastic order between the two maxima. Some numerical examples are presented for illustrating the established results.
SOME UNIFIED RESULTS ON COMPARING LINEAR COMBINATIONS OF INDEPENDENT GAMMA RANDOM VARIABLES
Authors: Kochar Subhash , Xu Maochao
Published: June 2012

In this paper, a new sufficient condition for comparing linear combinations of independent gamma random variables according to star ordering is given. This unifies some of the newly proved results on this problem. Equivalent characterizations between various stochastic orders are established by utilizing the new condition. The main results in this paper generalize and unify several results in the literature including those of Amiri, Khaledi, and Samaniego [2], Zhao [18], and Kochar and Xu [9].
OPTIMAL REPLACEMENT POLICIES UNDER ENVIRONMENT-DRIVEN DEGRADATION
Authors: Ulukus M. Yasin , Kharoufeh Jeffrey P. , Maillart Lisa M.
Published: June 2012

We examine the problem of optimally maintaining a stochastically degrading system using preventive and reactive replacements. The system's rate of degradation is modulated by an exogenous stochastic environment process, and the system fails when its cumulative degradation level first reaches a fixed deterministic threshold. The objective is to minimize the total expected discounted cost of preventively and reactively replacing such a system over an infinite planning horizon. To this end, we present and analyze a Markov decision process model. It is shown that, for each environment state, there exists an optimal threshold-type replacement policy. Additionally, empirical evidence suggests that, when the environment process is monotone, and the state-dependent degradation rates are totally ordered, the optimal threshold is monotone. Lastly, we derive closed-form bounds on the optimal thresholds.
Parkinson's disease – pathology, aetiology and diagnosis
Authors: Macphee Graeme JA , Stewart David A
Published: June 2012

Parkinson's disease is a progressive neurodegenerative condition. There is an increasing incidence and prevalence with advancing age and more cases are predicted as the population ages. Because of likely differing aetiology, genetics and pathology in individual patients, as well as confounding co-morbidities, diagnosis can be difficult even for specialists. We present an overview of the pathology, aetiology and differential diagnosis of Parkinson's disease in older people. The importance of specialist medical input in diagnosis is emphasized.
What can e-learning offer geriatric medicine in the UK?
Authors: Tullo Ellen , Newton Julia , Clapp Alison
Published: June 2012

The expansion of e-learning in medical education is a reflection of the inherent advantages that technology can bring to teaching and learning. Geriatric medicine has taken advantage of some of the benefits associated with e-learning in terms of undergraduate education, specialty training and interdisciplinary training. However, there are further opportunities and challenges to be met for geriatric medicine to make the very most of e-learning. This review outlines the terminology associated with e-learning, summarizes the advantages and potential problems, and considers the evidence base for the efficacy of e-learning. Current use of e-learning amongst professional groups is summarized and recommendations made for expanding the use of e-learning for all healthcare professionals working with older people.
Montreal Cognitive Assessment (MoCA): Validation Study for Vascular Dementia
Authors: Freitas Sandra , Simões Mário R. , Alves Lara , Vicente Margarida , Santana Isabel
Published: June 2012

The Montreal Cognitive Assessment (MoCA) is a brief instrument developed for the screening of milder forms of cognitive impairment, having surpassed the well-known limitations of the MMSE. The aim of the present study was to validate the MoCA as well as its short version, which was proposed by the NINDS-CSN VCI Harmonization Standards for screening Vascular Dementia (VaD) patients. The results, based on a homogeneous sample of 34 VaD patients, indicate that the MoCA is a psychometrically valid and reliable instrument for cognitive screening in VaD patients, showing excellent discriminant validity. Both the full and short versions of the MoCA had excellent diagnostic accuracy in discriminating VaD patients, exhibiting an area under curve (AUC) higher than the MMSE [AUC(MoCA full version) = .950; 95% IC = .868–.988; AUC(MoCA short version) = .936; 95% IC = .849–.981; AUC(MMSE) = .860; 95% IC = .754–.932]. With a cutoff below 17 on the MoCA full version and 8 on the short version, the results for sensitivity, specificity, positive and negative predictive values, and classification accuracy were superior compared to the MMSE. In conclusion, both versions of the MoCA are valid, reliable, sensitive and accurate screening instruments for VaD patients. (JINS, 2012, 18, 1–10)
Kant's Refutation of Idealism: Once More Unto the Breach
Authors: Dicker Georges
Published: June 2012

In ‘Kant's Refutation of Idealism’ (Noûs, 47), I defend a version of the Refutation, pioneered by Paul Guyer inKant and the Claims of Knowledge, whose core idea is that the only way that one can know the order of one's own past experiences, except in certain rare cases, is by correlating them with the successive states of perceived external objects that caused the experiences. Andrew Chignell has offered a probing critique of my reconstruction of Kant's argument (Philosophical Quarterly, 60), and I have responded (Philosophical Quarterly, 61). In a rebuttal of my response, Chignell raises three new objections (Philosophical Quarterly, 61). My purpose in this paper is to reply to these.
Original Sin and Radical Evil: Kierkegaard and Kant
Authors: Fremstedal Roe
Published: June 2012

By comparing the theories of evil found in Kant and Kierkegaard, this article aims to shed new light on Kierkegaard, as well as on the historical and conceptual relations between the two philosophers. The author shows that there is considerable overlap between Kant's doctrine of radical evil and Kierkegaard's views on guilt and sin and argues that Kierkegaard approved of the doctrine of radical evil. Although Kierkegaard's distinction between guilt and sin breaks radically with Kant, there are more Kantian elements in Kierkegaard than was shown by earlier scholarship. Finally, Kierkegaard provides an alternative solution to the problem of the universality of guilt, a problem much discussed in the literature on Kant.
Rawls and Kantian Constructivism
Authors: Kaufman Alexander
Published: June 2012

John Rawls's account of Kantian constructivism is perhaps his most striking contribution to ethics. In this paper, I examine the relation between Rawls's constructivism and its foundation in Kantian intuitions. In particular, I focus on the progressive influence on Rawls's approach of the Kantian intuition that the substance of morality is best understood as constructed by free and equal people under fair conditions. Rawls's focus on this Kantian intuition, I argue, motivates the focus on social contract that grounds both his accounts of the original position and of reflective equilibrium. Critics, including Onora O'Neill and Larry Krasnoff, object that Rawls's view distorts various aspects of Kantian moral reasoning. I argue that these objections (i) exaggerate the distinctions between Kant's and Rawls's decision procedures and (ii) reflect an unnecessarily constricted view of Kant's moral thought.
Happiness Proportioned to Virtue: Kant and the Highest Good
Authors: O'Connell Eoin
Published: June 2012

This paper considers two contenders for the title of highest good in Kant's theory of practical reason: happiness proportioned to virtue and the maximization of happiness and virtue. I defend the ‘proportionality thesis’ against criticisms made by Andrews Reath and others, and show how it resolves a dualism between prudential and moral practical reasoning. By distinguishing between the highest good as a principle of evaluation and an object of agency, I conclude that the maximization of happiness and virtue is a corollary of the instantiation of the proportionality thesis.
Once Again: What is the ‘First Proposition’ in Kant's Groundwork? Some Refinements, a New Proposal, and a Reply to Henry Allison
Authors: Schönecker Dieter
Published: June 2012

Discussing the concept of duty in Groundwork 1, Kant refers to a ‘second proposition’ and a ‘third proposition’, the latter being a ‘Folgerung aus beiden vorigen’. However, Kant does not identify what the ‘first proposition’ is. In this paper, I will argue that the first proposition is this: An action from duty is an action from respect for the moral law. I defend this claim against a critique put forward by Allison according to which ‘respect’ is a concept that is not, and could not be, introduced in paragraphs 9–13 of Groundwork 1. Further, I will argue that the first proposition as I understand it can also be reconstructed as the conclusion (‘Folgerung’) of a deductive argument proper; however, I will also discuss the option that ‘Folgerung’ could be understood as a corollary rather than a conclusion. Finally, Allison's own interpretation will be criticized.
What Does Kant Mean by ‘Power of Judgement’ in hisCritique of the Power of Judgement?
Authors: Teufel Thomas
Published: June 2012

The notion of ‘power of judgement’ in the title of Kant'sCritique of the Power of Judgementis commonly taken to refer to a cognitive power inclusive of both determining judgement and reflecting judgement. I argue, first, that this seemingly innocuous view is in conflict both with the textual fact that Kant attempts a Critical justification of the reflecting power of judgement – only – and with the systematic impossibility of a transcendentally grounded determining power of judgement. The conventional response to these difficulties is to point out that, Kant's systematic ambitions in the thirdCritiquenotwithstanding, reflection, qua concept-forming synthesis, is too closely tied to determination to be a cognitive power in its own right. I argue, second, that this response is question-begging, since the notion of reflection it employs is not only not one central to the thirdCritiquebut one antecedently tied to the understanding. I argue, third, that Kant's discussion, in the pivotal § § 76–7, of our cognitive relation to sensible particularity addresses an epistemic problem present (but not raised) in theCritique of Pure Reason. This is the problem of the synthesizability, qua absolute unity, of unsynthesized intuitions. Solving this problem requires Critical justification of a principle of reflection. It follows that Kant's systematic ambitions in the thirdCritiqueare appropriate. Given the problem Kant seeks to address, he must offer what he takes himself to be offering: aCritique of the(Reflecting)Power of Judgement.
A Kantian Critique of the Care Tradition: Family Law and Systemic Justice
Authors: Varden Helga
Published: June 2012

Liberal theories of justice have been rightly criticized for two things by care theorists. First, they have failed to deal with private care relations’ inherent (inter)dependency, asymmetry and particularity. Second, they have been shown unable properly to address the asymmetry and dependency constitutive of care workers’ and care-receivers’ systemic conditions. I apply Kant’s theory of right to show that current care theories unfortunately reproduce similar problems because they also argue on the assumption that good care requires only virtuous private individuals. Giving up this assumption enables us to solve the problems regarding both private care relations and systemic injustice.
The Sources and Interpretation of Olympic Law
Authors: James Mark , Osborn Guy
Published: June 2012

In this article, Mark James and Guy Osborn discuss how the relationships between the various members of the Olympic Movement are governed by the Olympic Charter and the legal framework within which an edition of the Olympic Games is organised. The legal status of the Charter and its interpretation by the Court of Arbitration for Sport are examined to identify who is subject to its terms and how challenges to its requirements can be made. Finally, by using the UK legislation that has been enacted to regulate advertising and trading at London 2012, the far-reaching and sometimes unexpected reach of Olympic Law is explored.
Olympics and International Sports Law Research Guide
Authors: Cho Esther
Published: June 2012

The Olympic Games are the world's most recognised international sporting event alongside the FIFA World Cup. Started in ancient Greece, the Olympic Games were revived in modern times in 1896 and occur every four years. This article, by Esther Cho, discusses how to research the structure and legal aspects of the Olympic Movement. It also encompasses the general array of international sports law resources connected to the Olympic Movement.
A Mare's Nest? The Jockey Club and Judicial Review of Sports Governing Bodies
Authors: Morgan Jonathan
Published: June 2012

In this article Jonathan Morgan reveals how the tradition of self-regulation in British sport has raised difficult questions for lawyers. On what basis can the decisions of governing bodies – which are clearly not organs of the state – be challenged? The Jockey Club was a regular subject of legal challenges from the mid 20th Century. An analysis of those cases illuminates the wider debate concerning the basis and extent of judicial review in English law.
Copyright and Contracts: the Use of Electronic Resources Provided by University Libraries
Authors: Shelly Marita , Jackson Margaret
Published: June 2012

Universities enter into contracts with publishers or providers of aggregated resources on behalf of university libraries to provide staff and students with access to material in electronic format for educational and research purposes. Following a brief review of twelve database provider contracts, our research demonstrates that Australian academics are potentially breaching the contractual terms and conditions of electronic resources when accessing, downloading and printing articles and other materials. They are covered for research purposes, but not for educational purposes.
Online Legal Information Systems in India: a Case Study from the Faculty of Law, University of Delhi
Authors: Bhardwaj Raj Kumar
Published: June 2012

In this digital age, users require immediate access to information. To foster the process of research, the legal fraternity demands efficient online legal information systems. Raj Kumar Bhardwaj provides a view from India and reports on a case study that has been conducted on the use of various legal information databases in the Faculty of Law, University of Delhi, India. In his paper, he also reviews and discusses the various aspects relating to legal information retrieval systems, with particular reference to the various essential legal databases that cover Indian law.
Aromatase inhibitors and mood disturbances
Authors: Rocha-Cadman Xiomara , Massie Mary Jane , Du Hamel Katherine
Published: June 2012

We describe the case of a 56-year old woman with no prior psychiatric history who was diagnosed with hormone receptor positive early-stage breast cancer and who developed severe mood changes after administration of anastrozole, which resolved after discontinuation of treatment. Aromatase inhibitors (AIs) are the preferred hormonal approach for postmenopausal women with estrogen hormone sensitive breast cancer. The third-generation agents (anastrozole, letrozole, and exemestane) have been shown to be more effective and safer than the selective estrogen receptor modulators tamoxifen and raloxifen. Treatment strategies with these agents include the use of an AI as an upfront strategy for 5 years, as a sequential approach after 2–3 years of tamoxifen, or as extended use after the classical 5 years of tamoxifen. The side effects of AIs, as compared with selective estrogen receptor modulators, are different, reflecting the specific mechanism of action of these drugs. AIs are well tolerated and cause a lower incidence of gynecological symptoms (vaginal bleeding, discharge, and endometrial neoplasia), venous thromboembolic events, and hot flashes compared with tamoxifen. However, the use of AIs have been associated with loss of bone density, arthralgia, myalgia, a negative effect on lipid metabolism, and cardiovascular risk (Tomao et al., 2011). Mood disturbances, somnolence, anxiety, fatigue, hot flashes, and memory impairment have been reported among patients receiving anastrozole as adjuvant therapy.
Measures of birth size in relation to risk of prostate cancer: the Malmö Diet and Cancer Study, Sweden
Authors: Lahmann P. H. , Wallström P. , Lissner L. , Olsson H. , Gullberg B.
Published: June 2012

There is some evidence that perinatal factors, specifically birth weight (BW), may be related to the onset of prostate cancer (PRCA). This case–control study, nested within the Malmö Diet and Cancer Cohort Study, used archived birth record data from 308 incident PRCA cases diagnosed between 1991 and 2005, and 637 age-matched controls among 4781 men born (1923–1945) in Malmö and Lund, Sweden. We applied conditional logistic regression to examine the birth size–PRCA association, including tumour subtypes, adjusting for perinatal and adult factors. Compared with controls, cases had a non-significantly higher mean BW and were more likely to have high (>4000 g) BW (21% v. 18%), but did not differ in other birth size measures, nor in mean adult body mass index . We observed a non-linear association between BW and PRCA risk. Compared with BWs between 3000 and 3500 g (reference), the fully adjusted odds ratios (OR, 95% CI) were 0.55 (0.33–0.91) for <3000 g, 0.86 (0.61–1.22) for 3500–4000 g and 0.98 (0.64–1.50) for >4000 g. Among men with aggressive tumours, the reduction in risk for those with BWs <3000 g (OR 0.26, 95% CI 0.09–0.72) was stronger than the rate of risk for PRCA overall. Crude risk estimates were minimally attenuated when adjusted for gestational age, maternal age, birth order and adult factors. Birth length, head circumference and placental weight were not associated with prostate cancer. Our results indicate a protective effect of lower BW on risk of total and aggressive prostate cancer, rather than any direct effect of larger birth size.
Stress‐ and aftershock‐constrained joint inversions for coseismic and postseismic slip applied to the 2004 M6.0 Parkfield earthquake
Authors: Wang Lifeng , Hainzl Sebastian , Zöller Gert , Holschneider Matthias
Published: June 2012

Both aftershocks and geodetically measured postseismic displacements are important markers of the stress relaxation process following large earthquakes. Postseismic displacements can be related to creep‐like relaxation in the vicinity of the coseismic rupture by means of inversion methods. However, the results of slip inversions are typically non‐unique and subject to large uncertainties. Therefore, we explore the possibility to improve inversions by mechanical constraints. In particular, we take into account the physical understanding that postseismic deformation is stress‐driven, and occurs in the coseismically stressed zone. We do joint inversions for coseismic and postseismic slip in a Bayesian framework in the case of the 2004 M6.0 Parkfield earthquake. We perform a number of inversions with different constraints, and calculate their statistical significance. According to information criteria, the best result is preferably related to a physically reasonable model constrained by the stress‐condition (namely postseismic creep is driven by coseismic stress) and the condition that coseismic slip and large aftershocks are disjunct. This model explains 97% of the coseismic displacements and 91% of the postseismic displacements during day 1–5 following the Parkfield event, respectively. It indicates that the major postseismic deformation can be generally explained by a stress relaxation process for the Parkfield case. This result also indicates that the data to constrain the coseismic slip model could be enriched postseismically. For the 2004 Parkfield event, we additionally observe asymmetric relaxation process at the two sides of the fault, which can be explained by material contrast ratio across the fault of ∼1.15 in seismic velocity.
Variations in hydrological connectivity of Australian semiarid landscapes indicate abrupt changes in rainfall‐use efficiency of vegetation
Authors: Moreno‐de las Heras Mariano , Saco Patricia M. , Willgoose Garry R. , Tongway David J.
Published: June 2012

Dryland vegetation frequently shows self‐organized spatial patterns as mosaic‐like structures of sources (bare areas) and sinks (vegetation patches) of water runoff and sediments with variable interconnection. Good examples are banded landscapes displayed by Mulga in semiarid Australia, where the spatial organization of vegetation optimizes the redistribution and use of water (and other scarce resources) at the landscape scale. Disturbances can disrupt the spatial distribution of vegetation causing a substantial loss of water by increasing landscape hydrological connectivity and consequently, affecting ecosystem function (e.g., decreasing the rainfall‐use efficiency of the landscape). We analyze (i) connectivity trends obtained from coupled analysis of remotely sensed vegetation patterns and terrain elevations in several Mulga landscapes subjected to different levels of disturbance, and (ii) the rainfall‐use efficiency of these landscapes, exploring the relationship between rainfall and remotely sensed Normalized Difference Vegetation Index. Our analyses indicate that small reductions in the fractional cover of vegetation near a particular threshold can cause abrupt changes in ecosystem function, driven by large nonlinear increases in the length of the connected flowpaths. In addition, simulations with simple vegetation‐thinning algorithms show that these nonlinear changes are especially sensitive to the type of disturbance, suggesting that the amount of alterations that an ecosystem can absorb and still remain functional largely depends on disturbance type. In fact, selective thinning of the vegetation patches from their edges can cause a higher impact on the landscape hydrological connectivity than spatially random disturbances. These results highlight surface connectivity patterns as practical indicators for monitoring landscape health.
The effect of phase scintillations on the accuracy of phase screen simulation using deterministic screens derived from GPS and ALTAIR measurements
Authors: Carrano Charles S. , Groves Keith M. , Caton Ronald G.
Published: June 2012

Radio receivers capable of high‐rate sampling such as GPS scintillation monitors and the ALTAIR VHF/UHF tracking radar can measure ionospheric phase fluctuations suitable for scintillation modeling using phase screen techniques. For modeling purposes, the phase variations caused by the refractive effects of electron density irregularities encountered along the propagation path are desired. The phase fluctuations measured by ground‐based receivers, however, also include the unwanted effects of diffraction (phase scintillations). In this paper, we investigate the effect of phase scintillations on the accuracy of phase screen simulation when using the phase measured on the ground as a proxy for the ionospheric screen. Using stochastic and deterministic (measured) phase screens, we quantitatively assess the accuracy of this approach by cross‐correlating the predicted and measured intensity fluctuations. We find that the intensity cross‐correlation is less than unity even in the weak scatter limit, due to the presence of weak phase scintillations. This correlation decreases rapidly with increasing irregularity strength once rapid transitions in the phase (strong phase scintillations) develop. We demonstrate that, when using the measured phase on the ground as a proxy for the ionospheric screen, both the temporal structure of simulated fluctuations and their statistics deviate increasingly from those of the measurements as the turbulence strength increases, especially when strong phase scintillations are present. We also demonstrate that back‐propagating the complex signal up to ionospheric altitudes prior to the forward propagation calculation yields improved results, but some errors still remain as a consequence of neglecting amplitude fluctuations which develop inside the random medium.
Seismic imaging of the Cocos plate subduction zone system in central Mexico
Authors: Kim YoungHee , Miller Meghan S. , Pearce Frederick , Clayton Robert W.
Published: June 2012

Broadband data from the Meso‐America Subduction Experiment (MASE) line in central Mexico were used to image the subducted Cocos plate and the overriding continental lithosphere beneath central Mexico using a generalized radon transform based migration. Our images provide insight into the process of subducting relatively young oceanic lithosphere and its complex geometry beneath continental North America. The converted and reverberated phase image shows complete horizontal tectonic underplating of the Cocos oceanic lithosphere beneath the North American continental lithosphere, with a clear image of a very thin low‐velocity oceanic crust (7–8 km) which dips at 15–20 degrees at Acapulco then flattens approximately 300 km from the Middle America Trench. Farther inland the slab then appears to abruptly change from nearly horizontal to a steeply dipping geometry of approximately 75 degrees underneath the Trans‐Mexican Volcanic Belt (TMVB). Where the slab bends underneath the TMVB, the migrated image depicts the transition from subducted oceanic Moho to continental Moho at ∼230 km from the coast, neither of which were clearly resolved in previous seismic images. The deeper seismic structure beneath the TMVB shows a prominent negative discontinuity (fast‐to‐slow) at ∼65–75 km within the upper mantle. This feature, which spans horizontally beneath the arc (∼100 km), may delineate the top of a layer of ponded partial melt.
Temporal changes of seismic velocity associated with the 2006 Mw 6.1 Taitung earthquake in an arc‐continent collision suture zone
Authors: Yu Tai‐Chieh , Hung Shu‐Huei
Published: June 2012

To detect temporal changes of elastic properties associated with the 2006 Mw 6.1 Taitung earthquake in southeast Taiwan, whereby the collision between the Luzon arc riding on the Philippine Sea plate and the Asian margin is taking place, we construct the Green's functions from auto‐ and cross‐correlation function (ACF and CCF) of continuous ambient noise between stations. Time lapse changes in the retrieved coda arrivals are estimated for monitoring spatiotemporal variations of seismic velocities around the ruptured fault zones. To the south of the main shock epicenter where the earthquake may have ruptured along two perpendicularly‐intersecting fault planes resulting in intense coseismic slip and widely‐dispersed aftershocks, the ACFs (2–8 Hz) at nearby stations reveal a large, sudden velocity drop of over 1% after the event occurrence. The CCFs (0.1–0.9 Hz) also show moderate reduction about 0.1% for the interstation paths traveling through the southeast quadrant of the focal sphere which has experienced the maximum peak ground acceleration and dilatational strain change. The intense seismic shaking combined with the rupture‐induced damage near the junction of the two faults is the most plausible cause for such localized, but significant coseismic velocity reduction. The response of groundwater levels to precipitation is in‐phase correlated with velocity variations over 3 years of investigation. Unlike the postseismic surface displacements gradually relaxed, the velocity remained slow until October 2006 due to the typhoon‐induced heavy rains between May and September.
The Indian summer monsoon during peaks in the 11 year sunspot cycle
Authors: van Loon Harry , Meehl Gerald A.
Published: June 2012

An analysis of sea‐level pressure anomalies at 14 sunspot peaks in the 11 year solar cycle in the Indian region in summer shows that the mean sea level pressure anomalies consist of relatively high pressure over land surrounded by low pressure anomalies over the sea. This signal is robust enough to appear when the data are divided into two segments. The accompanying mean rainfall anomalies, with anomalies as high as 20% above normal, have maxima on the coasts and over water and are an enhancement of the mean Indian monsoon rainfall. In the sunspot peaks the Findlater Jet appears to shift east and strengthen somewhat, consistent with the lower sea level pressure and stronger monsoon rainfall.
A year of internal Poincaré waves in southern Lake Michigan
Authors: Choi Jun , Troy Cary D. , Hsieh Tsung‐Chan , Hawley Nathan , McCormick Michael J.
Published: June 2012

A unique set of full year, deep water observations from the middle of Lake Michigan's southern basin are analyzed to quantify the seasonal variability of the dominant near‐inertial internal Poincaré wave. At this mid‐lake location, the Poincaré wave is seen to describe more than 80% of the observed surface current variability for much of the year, with characteristic near‐inertial frequency and clockwise‐rotating velocities. The dominance of the near‐inertial seiche on the flow decreases with depth. The wave persists during the “stratified period,” roughly May through late December, and is supported by as few as 1–2 degrees of thermal stratification over 150 m; only after complete water column mixing does the wave go dormant for January through April. The strongest Poincaré wave activity is seen to correspond to the period of strongest summer thermal stratification (August), in spite of the relatively weak winds at this time. A simple inertial slab model optimized with linear friction is shown to capture the seasonal variability of the near‐inertial energy at this location reasonably well. The vertical structure of the wave shows good agreement with that calculated with a standard normal modes formulation, which is in turn used to characterize the potential shear and mixing caused by the wave. Late‐spring and summer events of elevated Poincaré wave activity are shown to generate sufficiently strong shear with persistent periods of sub‐1 Richardson numbers within the thermocline, suggesting that the near‐inertial seiche is likely generating thermocline instabilities in the lake's interior.
Orbital velocity and breaking in steep random gravity waves
Authors: Grue John , Jensen Atle
Published: June 2012

Laboratory measurements by PIV of strongly nonlinear irregular waves are compared to orbital velocity calculations of directional field waves. Nondimensional fluid velocities are obtained dividing by a local wave phase speed which is evaluated from a local wave number and wave slope. 30 laboratory waves have slope in the range 0.14–0.4. Nine among the waves have a slope of about 0.3, and breaking is measured in four among the waves. A backward breaking wave has local wave slope as small as 0.22. Wave induced acceleration is measured. Orbital velocity of two samples of directional field waves in storm conditions are calculated by nonlinear method and compared to the laboratory kinematics. The effect of the ocean surface current is accounted for. The field data include wave groups of local elevation gradient up to 0.3. The sample with the longest fetch exhibits nondimensional orbital velocities that are similar to the laboratory waves including levels up to breaking. In the other field sample, nondimensional fluid velocities are proportional to the local wave slope (up to 0.3), and velocities are well below breaking level.
Climate response of the South Asian monsoon system to anthropogenic aerosols
Authors: Ganguly Dilip , Rasch Philip J. , Wang Hailong , Yoon Jin‐Ho
Published: June 2012

The equilibrium climate response to the total effects (direct, indirect and semi‐direct effects) of aerosols arising from anthropogenic and biomass burning emissions on the South Asian summer monsoon system is studied using a coupled atmosphere‐slab ocean model. Our results suggest that anthropogenic and biomass burning aerosols generally induce a reduction in mean summer monsoon precipitation over most parts of the Indian subcontinent, strongest along the western coastline of the Indian peninsula and eastern Nepal region, but modest increases also occur over the north western part of the subcontinent. While most of the noted reduction in precipitation is triggered by increased emissions of aerosols from anthropogenic activities, modest increases in the north west are mostly associated with decreases in local emissions of aerosols from forest fire and grass fire sources. Anthropogenic aerosols from outside Asia also contribute to the overall reduction in precipitation but the dominant contribution comes from aerosol sources within Asia. Local emissions play a more important role in the total rainfall response to anthropogenic aerosol sources during the early monsoon period, whereas both local as well as remote emissions of aerosols play almost equally important roles during the later part of the monsoon period. While precipitation responses are primarily driven by local aerosol forcing, regional surface temperature changes over the region are strongly influenced by anthropogenic aerosols from sources further away (non‐local changes). Changes in local anthropogenic organic and black carbon emissions by as much as a factor of two (preserving their ratio) produce the same basic signatures in the model's summer monsoon temperature and precipitation responses.
Calibration of two‐dimensional floodplain modeling in the central Atchafalaya Basin Floodway System using SAR interferometry
Authors: Jung Hahn Chul , Jasinski Michael , Kim Jin‐Woo , Shum C. K. , Bates Paul , Neal Jeffrey , Lee Hyongki , Alsdorf Doug
Published: June 2012

Two‐dimensional (2‐D) satellite imagery has been increasingly employed to improve prediction of floodplain inundation models. However, most focus has been on validation of inundation extent, with little attention on the spatial variations of water elevation and slope. The availability of high resolution Interferometric Synthetic Aperture Radar (InSAR) imagery offers unprecedented opportunity for quantitative validation of surface water heights and slopes derived from 2D hydrodynamic models. In this study, the LISFLOOD‐ACC hydrodynamic model is applied to the central Atchafalaya Basin Floodway System, Louisiana, during high flows typical of spring floods in the Mississippi Delta region, for the purpose of demonstrating the utility of InSAR in 2‐D floodplain model calibration. Two schemes calibrating Manning's roughness in channels and floodplains are compared. First, the model is calibrated in terms of water elevations at a single in situ gage during a 62‐d simulation period from 1 April 2008 to 1 June 2008. Second, the model is calibrated in terms of water elevation changes calculated from ALOS PALSAR 2D imagery acquired on 16 April 2008 and 1 June 2009, an interval of 46 d. The best‐fit model shows that the mean absolute error is 5.7 cm/46 d for InSAR water level calibration. Daily storage changes within the ∼230‐km2 model area are also calculated to be on the order of 107 m3 d−1 during high water of the modeled period. The favorable comparison between both approaches demonstrates the feasibility of SAR interferometry for 2‐D hydrodynamic model calibration and for improved understanding of complex floodplain hydrodynamics.
Kinetic analysis reveals successive steps leading to miRNA‐mediated silencing in mammalian cells
Authors: Béthune Julien , Artus‐Revel Caroline G , Filipowicz Witold
Published: June 2012

MicroRNAs (miRNAs) regulate most cellular functions, acting by posttranscriptionally repressing numerous eukaryotic mRNAs. They lead to translational repression, deadenylation and degradation of their target mRNAs. Yet, the relative contributions of these effects are controversial and little is known about the sequence of events occurring during the miRNA‐induced response. Using stable human cell lines expressing inducible reporters, we found that translational repression is the dominant effect of miRNAs on newly synthesized targets. This step is followed by mRNA deadenylation and decay, which is the dominant effect at steady state. Our findings have important implications for understanding the mechanism of silencing and reconcile seemingly contradictory data.
Intestinal peptidases form functional complexes with the neutral amino acid transporter B0AT1
Authors: Fairweather Stephen J. , Bröer Angelika , O'Mara Megan L. , Bröer Stefan
Published: June 2012

The brush-border membrane of the small intestine and kidney proximal tubule are the major sites for the absorption and re-absorption of nutrients in the body respectively. Transport of amino acids is mediated through the action of numerous secondary active transporters. In the mouse, neutral amino acids are transported by B0AT1 [broad neutral (0) amino acid transporter 1; SLC6A19 (solute carrier family 6 member 19)] in the intestine and by B0AT1 and B0AT3 (SLC6A18) in the kidney. Immunoprecipitation and Blue native electrophoresis of intestinal brush-border membrane proteins revealed that B0AT1 forms complexes with two peptidases, APN (aminopeptidase N/CD13) and ACE2 (angiotensin-converting enzyme 2). Physiological characterization of B0AT1 expressed together with these peptidases in Xenopus laevis oocytes revealed that APN increased the substrate affinity of the transporter up to 2.5-fold and also increased its surface expression (Vmax). Peptide competition experiments, in silico modelling and site-directed mutagenesis of APN suggest that the catalytic site of the peptidase is involved in the observed changes of B0AT1 apparent substrate affinity, possibly by increasing the local substrate concentration. These results provide evidence for the existence of B0AT1-containing digestive complexes in the brush-border membrane, interacting differentially with various peptidases, and responding to the dynamic needs of nutrient absorption in the intestine and kidney.
miR-297 modulates multidrug resistance in human colorectal carcinoma by down-regulating MRP-2
Authors: Xu Ke , Liang Xin , Shen Ke , Cui Daling , Zheng Yuanhong , Xu Jianhua , Fan Zhongze , Qiu Yanyan , Li Qi , Ni Lei , Liu Jianwen
Published: June 2012

Colorectal carcinoma is a frequent cause of cancer-related death in men and women. miRNAs (microRNAs) are endogenous small non-coding RNAs that regulate gene expression negatively at the post-transcriptional level. In the present study we investigated the possible role of microRNAs in the development of MDR (multidrug resistance) in colorectal carcinoma cells. We analysed miRNA expression levels between MDR colorectal carcinoma cell line HCT116/L-OHP cells and their parent cell line HCT116 using a miRNA microarray. miR-297 showed lower expression in HCT116/L-OHP cells compared with its parental cells. MRP-2 (MDR-associated protein 2) is an important MDR protein in platinum-drug-resistance cells and is a predicted target of miR-297. Additionally miR-297 was down-regulated in a panel of human colorectal carcinoma tissues and negatively correlated with expression levels of MRP-2. Furthermore, we found that ectopic expression of miR-297 in MDR colorectal carcinoma cells reduced MRP-2 protein level and sensitized these cells to anti-cancer drugs in vitro and in vivo. Taken together, our findings suggest that miR-297 could play a role in the development of MDR in colorectal carcinoma cells, at least in part by modulation of MRP-2.
A novel derivative of decursin, CSL‐32, blocks migration and production of inflammatory mediators and modulates PI3K and NF‐κB activities in HT1080 cells
Authors: Lee Seung‐Hee , Lee Jee Hyun , Kim Eun‐Ju , Kim Won‐Jung , Suk Kyoungho , Kim Joo‐Hwan , Song Gyu Yong , Lee Won‐Ha
Published: June 2012

Decursin and related coumarin compounds in herbal extracts have a number of biological activities against inflammation, angiogenesis and cancer. We have analysed a derivative of decursin (CSL‐32) for activity against inflammatory activation of cancer cells, such as migration, invasion and expression of pro‐inflammatory mediators. The human fibrosarcoma cell line, HT1080, was treated with TNFα (tumour necrosis factor α) in the presence or absence of CSL‐32. The cellular responses and modification of signalling adapters were analysed with respect to the production of pro‐inflammatory mediators, as also migration, adhesion and invasion. Treatment of HT1080 cells with CSL‐32 inhibited their proliferation, without affecting cell viability, and TNFα‐induced expression of pro‐inflammatory mediators, such as MMP‐9 (matrix metalloproteinase‐9) and IL‐8 (interleukin‐8). CSL‐32 also suppressed phosphorylation and degradation of IκB (inhibitory κB), phosphorylation of p65 subunit of NF‐κB (nuclear factor‐κB) and nuclear translocation of NF‐κB, which are required for the expression of pro‐inflammatory mediators. In addition, CSL‐32 inhibited invasion and migration of HT1080 cells, as also cellular adhesion to fibronectin, an ECM (extracellular matrix) protein. CSL‐32 treatment resulted in a dose‐dependent inhibition of PI3K (phosphoinositide 3‐kinase) activity, required for the cellular migration. The analyses show that CSL‐32 inhibits processes associated with inflammation, such as the production of pro‐inflammatory mediators, as well as adhesion, migration and invasion in HT1080 cells.
Cell versus protoplasm: revisionist history
Authors: Welch G. Rickey , Clegg James S.
Published: June 2012

Recent investigations give reason to question anew the historical status of the ‘cell theory’ as the ultimate driving force in the development of our understanding of life's processes at the most fundamental level. A revisitation of critical research papers and commentaries from the 19th Century shows that the disregarded (and historically maligned) ‘protoplasmic theory of life’ played a more deterministic role in the early advancement of knowledge on cell structure and function.
Improvement of Voc and Jsc in CuInGaSe2 solar cells using a novel sandwiched CuGa/CuInGa/In precursor structure
Authors: Ru Hsu Hung , Chun Hsu Shu , Liu Yung-sheng
Published: June 2012

In this study, a novel structure using a sandwiched CuGa/CuInGa/In precursor layer is employed for improving the Voc and Jsc of a CIGS solar cell. The addition of a CuGa layer on the surface of CuInGa precursor enhanced the Ga concentration in the space charge region and thus enhanced the Voc by about 18.2%. The addition of an In layer to the bottom of CuGa/CuInGa/In precursors increased the absorber solar spectrum edge and thus improved the Jsc by about 14%. The device conversion efficiency using this novel precursor structure was found to increase by about 50% from 6.2% to 9.5%.
Aminated graphene for DNA attachment produced via plasma functionalization
Authors: Baraket Mira , Stine Rory , Lee Woo K. , Robinson Jeremy T. , Tamanaha Cy R. , Sheehan Paul E. , Walton Scott G.
Published: June 2012

We demonstrate the use of a unique plasma source to controllably functionalize graphene with nitrogen and primary amines, thereby tuning the chemical, structural, and electrical properties. Critically, even highly aminated graphene remains electronically conductive, making it an ideal transduction material for biosensing. Proof-of-concept testing of aminated graphene as a bio-attachment platform in a biologically active field-effect transistor used for DNA detection is demonstrated.
Maximum-entropy closure of hydrodynamic moment hierarchies including correlations
Authors: Hughes Keith H. , Burghardt Irene
Published: June 2012

Generalized hydrodynamic moment hierarchies are derived which explicitly include nonequilibrium two-particle and higher-order correlations. The approach is adapted to strongly correlated media and nonequilibrium processes on short time scales which necessitate an explicit treatment of time-evolving correlations. Closure conditions for the extended moment hierarchies are formulated by a maximum-entropy approach, generalizing related closure procedures for kinetic equations. A self-consistent set of nonperturbative dynamical equations are thus obtained for a chosen set of single-particle and two-particle (and possibly higher-order) moments. Analytical results are derived for generalized Gaussian closures including the dynamic pair distribution function and a two-particle correction to the current density. The maximum-entropy closure conditions are found to involve the Kirkwood superposition approximation.
Quantum charge transport and conformational dynamics of macromolecules
Authors: Boninsegna L. , Faccioli P.
Published: June 2012

We study the dynamics of quantum excitations inside macromolecules which can undergo conformational transitions. In the first part of the paper, we use the path integral formalism to rigorously derive a set of coupled equations of motion which simultaneously describe the molecular and quantum transport dynamics, and obey the fluctuation/dissipation relationship. We also introduce an algorithm which yields the most probable molecular and quantum transport pathways in rare, thermally activated reactions. In the second part of the paper, we apply this formalism to simulate the propagation of a quantum charge during the collapse of a polymer from an initial stretched conformation to a final globular state. We find that the charge dynamics is quenched when the chain reaches a molten globule state. Using random matrix theory we show that this transition is due to an increase of quantum localization driven by dynamical disorder. We argue that collapsing conducting polymers may represent a physical realization of quantum small-world networks with dynamical rewiring probability.