bluuebunny/crossref_metadata_2025 huggingface dataset:
GRACE-Based Hydrological Drought Evaluation of the Yangtze River Basin, China
Authors: Zhang Dan , Zhang Qi , Werner Adrian D. , Liu Xiaomang
Published: December 2015

In this study, hydrological drought in the Yangtze River basin (YRB) is characterized based on Gravity Recovery and Climate Experiment (GRACE) total water storage (TWS). An artificial neural network approach is applied to extend the GRACE TWS observations (2003–12) to a longer TWS time series (1979–2012), which is well matched (Nash–Sutcliff efficiency of 0.83) to the GRACE data. Hydrological drought is identified by water storage deficit (WSD; the shortfall in TWS from the average value) in three consecutive months. The method builds on previous research by considering potentially ineffective interdrought events and by characterizing drought recovery time from a multidecadal TWS time series. The results show that the YRB was in hydrological drought 29 times during 1979–2012, and the three subbasins of the YRB (upper, middle, and lower YRB) experienced between 21 and 28 hydrological drought events during the same period. The drought recovery time, defined as the time required for WSD to recover to average conditions, is evaluated by a simple statistical approach based on the empirical cumulative distribution function. The average drought recovery time is 3.3 months for the entire YRB and ranges from 2.3 to 3.4 months for the three subbasins. The severest YRB drought occurred during 2003–08 as a result of below-average precipitation, high temperatures, and intense human activities. The results demonstrate that GRACE data are useful for reconstructing the TWS time series for a large river basin, from which hydrological drought can be characterized, and for investigating spatial and temporal trends in water storage conditions.
Mesoscale to Submesoscale Wavenumber Spectra in Drake Passage
Authors: Rocha Cesar B. , Chereskin Teresa K. , Gille Sarah T. , Menemenlis Dimitris
Published: December 2015

This study discusses the upper-ocean (0–200 m) horizontal wavenumber spectra in the Drake Passage from 13 yr of shipboard ADCP measurements, altimeter data, and a high-resolution numerical simulation. At scales between 10 and 200 km, the ADCP kinetic energy spectra approximately follow ak−3power law. The observed flows are more energetic at the surface, but the shape of the kinetic energy spectra is independent of depth. These characteristics resemble predictions of isotropic interior quasigeostrophic turbulence. The ratio of across-track to along-track kinetic energy spectra, however, significantly departs from the expectation of isotropic interior quasigeostrophic turbulence. The inconsistency is dramatic at scales smaller than 40 km. A Helmholtz decomposition of the ADCP spectra and analyses of synthetic and numerical model data show that horizontally divergent, ageostrophic flows account for the discrepancy between the observed spectra and predictions of isotropic interior quasigeostrophic turbulence. In Drake Passage, ageostrophic motions appear to be dominated by inertia–gravity waves and account for about half of the near-surface kinetic energy at scales between 10 and 40 km. Model results indicate that ageostrophic flows imprint on the sea surface, accounting for about half of the sea surface height variance between 10 and 40 km.
Action Research: Applying a Bilingual Parallel Corpus Collocational Concordancer to Taiwanese Medical School EFL Academic Writing
Authors: Reynolds Barry Lee
Published: December 2015

Lack of knowledge in the conventional usage of collocations in one’s respective field of expertise cause Taiwanese students to produce academic writing that is markedly different than more competent writing. This is because Taiwanese students are first and foremost English as a Foreign language (EFL) readers and may have difficulties picking up on the regularly encountered patterns of collocating words found in texts, since nothing on the page highlights collocations as such. As one step in determining a solution to this problem, this paper reports on action research that took place in an EFL writing classroom where undergraduate Taiwanese medical students (n = 25) were encouraged to self-edit their academic writing for verb-noun collocation errors through the use of a web-based English/Chinese bilingual parallel corpus collocational concordancer. Statistical analysis of students’ drafts revealed the use of the collocational concordancer resulted in verb-noun collocation accuracy increasing steadily with each subsequent draft for two essay types (i.e. descriptive and opinion). However, qualitative analysis of student feedback regarding their experience in using the collocational concordancer to self-edit their academic writing showed a difference in acceptance and success. Furthermore, students expressed negativity towards the EFL writing teacher requesting students to self-edit academic writing. The collocational concordancer functions, nuanced statistical results in terms of collocation accuracy, and pedagogical implications of the action research results are discussed.
“I Want to Do More and Change Things”: Reframing CTE Toward Possibilities in Urban Education
Authors: Jocson Korina M.
Published: December 2015

This article addresses the discourse on career and technical education (CTE) from a multiperspectival approach to challenge the persisting academic-vocational divide. The author illustrates the paradoxical rhetoric in CTE, then shares a personal experience, and draws on ethnographic research to reveal a different understanding of enabling human capacity to support racially and culturally minoritized youth. In the end, the author suggests that a push beyond the language of investment and skills embedded in educational reform becomes all the more important in preparing youth for the future. Implications for practice, research, and policy toward possibilities in urban education are also discussed.
China’s diplomatic initiatives in the Middle East: the quest for a great-power role in the region
Authors: Evron Yoram
Published: December 2015

Since the early 2010s, there have been mounting calls in China to intensify its role in the Middle East. But seeing the region as highly turbulent, Beijing seems to restrain its political involvement there. So what role does China actually strive for in the Middle East? To answer this question, the article first presents China’s discourse on its future role in the region; next, it analyzes China’s involvement in the Israeli–Palestinian conflict and the Syrian civil war, focusing on three diplomatic initiatives it has made concerning these issues. The argument here is that China strives to be part of major processes in the Middle East and attempts to advance its values and interests there, but in a unique pattern of big-power involvement in the region, it tries to achieve this without intensive investment of political, economic, and military resources.
Marshall Berman, November 24, 1940–September 11, 2013
Authors: Meehan James
Published: December 2015

This is a brief memorial tribute to Marshall Berman, which portrays him as a humanist chronicler of the “heroism of modern life.” Berman’s four books achieve this by creative variations in three broad themes: modernism, Marxism, and the metropolis. In Berman’s work, the works of Marx are fruitfully mined for their humanistic vision (with no distinction between the early work and the later “scientific” work), but he makes use of many intellectual and artistic perspectives as well, transcending ideological or disciplinary boundaries, in search of an understanding of the promises and perils of modernism. The metropolis as the theater of the modern life is the implicit or explicit backdrop in his works, and he draws upon his own urban biography to demonstrate the everyday heroism of ordinary people. While vulnerable to criticism as eclectic and naively optimistic, Berman’s writing is critical and empathetic, and true to the spirit of a humanist Marxist understanding of both the disasters and opportunities of modernist capitalist society.
Ultra-fast magnetic resonance encephalography of physiological brain activity – Glymphatic pulsation mechanisms?
Authors: Kiviniemi Vesa , Wang Xindi , Korhonen Vesa , Keinänen Tuija , Tuovinen Timo , Autio Joonas , LeVan Pierre , Keilholz Shella , Zang Yu-Feng , Hennig Jürgen , Nedergaard Maiken
Published: December 2015

The theory on the glymphatic convection mechanism of cerebrospinal fluid holds that cardiac pulsations in part pump cerebrospinal fluid from the peri-arterial spaces through the extracellular tissue into the peri-venous spaces facilitated by aquaporin water channels. Since cardiac pulses cannot be the sole mechanism of glymphatic propulsion, we searched for additional cerebrospinal fluid pulsations in the human brain with ultra-fast magnetic resonance encephalography. We detected three types of physiological mechanisms affecting cerebral cerebrospinal fluid pulsations: cardiac, respiratory, and very low frequency pulsations. The cardiac pulsations induce a negative magnetic resonance encephalography signal change in peri-arterial regions that extends centrifugally and covers the brain in ≈1 Hz cycles. The respiratory ≈0.3 Hz pulsations are centripetal periodical pulses that occur dominantly in peri-venous areas. The third type of pulsation was very low frequency (VLF 0.001–0.023 Hz) and low frequency (LF 0.023–0.73 Hz) waves that both propagate with unique spatiotemporal patterns. Our findings using critically sampled magnetic resonance encephalography open a new view into cerebral fluid dynamics. Since glymphatic system failure may precede protein accumulations in diseases such as Alzheimer's dementia, this methodological advance offers a novel approach to image brain fluid dynamics that potentially can enable early detection and intervention in neurodegenerative diseases.
Increased risk of trigeminal neuralgia in patients with migraine: A nationwide population-based study
Authors: Lin Kuan-Hsiang , Chen Yung-Tai , Fuh Jong-Ling , Wang Shuu-Jiun
Published: December 2015

Objectives

The objectives of this article are to evaluate the association between migraine and trigeminal neuralgia and to investigate the effects of age, sex, migraine subtype, and comorbid risk factors on trigeminal neuralgia development.

Methods

This population-based cohort study was conducted using data from Taiwan’s National Health Insurance Research Database. Individuals aged ≥ 20 years with neurologist-diagnosed migraine between 2005 and 2009 were included. A non-headache age-, sex-, and propensity score-matched control cohort was selected for comparison. All participants were followed until the end of 2010, death, or the occurrence of trigeminal neuralgia. Cox proportional hazards regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for comparison of the risk of trigeminal neuralgia between groups.

Results

Both cohorts ( n = 137,529 each) were followed for a mean of 3.1 years. During the follow-up period, 575 patients (421,581 person-years) in the migraine cohort and 88 matched controls (438,712 person-years) were newly diagnosed with trigeminal neuralgia (incidence rates, 136.39 and 20.06/100,000 person-years, respectively). The HR for trigeminal neuralgia was 6.72 (95% CI, 5.37–8.41; p < 0.001). The association between migraine and trigeminal neuralgia remained significant in sensitivity analyses. Among migraine subtypes, patients with migraine with aura were at greater risk of trigeminal neuralgia development. No other significant interaction was identified in subgroup analyses.

Conclusions

Migraine is a previously unidentified risk factor for trigeminal neuralgia. The association between these conditions suggests a linked underlying mechanism, which is worthy of further exploration.
Art for Foulkes’ Sake or How I Learned to Stop Worrying and Trust the Group
Authors: Power Kevin
Published: December 2015

This article addresses the title of the GASI’s 15th Symposium in Lisbon, ‘Group-Analysis as Art and Science’. It is eclectic and seeks to expose some fallacies in certain areas of practice and theory, and questions the trend towards medico-technological practice rather than valuing group analysis as a creative practice that contains much more for its participants than mere ‘recovery’. The underlying argument is that the process-art of the group that the members participate in is the dynamo of change in the group.
Evaluating the Cognitive Consequences of Playing Portal for a Short Duration
Authors: Adams Deanne M. , Pilegard Celeste , Mayer Richard E.
Published: December 2015

Learning physics often requires overcoming common misconceptions based on naïve interpretations of observations in the everyday world. One proposed way to help learners build appropriate physics intuitions is to expose them to computer simulations in which motion is based on Newtonian principles. In addition, playing video games that require spatial processing may also facilitate the development of spatial skills that have been associated with learning in science, technology, engineering, and mathematics areas. Two studies were conducted to examine whether playing the first-person perspective puzzle game Portal causes improvements in physics intuitions and spatial cognition skills. In Experiment 1, college students played Portal, the two-dimensional puzzle game Tetris, or the anagram game TextTwist for 75 minutes. There were no significant differences on measures of naïve physics reasoning (selected from the Force Concept Inventory) or measures of spatial cognition (mental rotation and perspective taking). To determine whether Portal could influence formal physics learning, in Experiment 2 participants viewed a brief lesson on Newton’s laws of motion after playing one of the three games for 1 hour. The groups did not differ on subsequent tests of physics learning. This study shows that Portal was not successful in priming intuitions about motion or spatial abilities related to physics learning.
The geometric principles of general spiral bevel gears of local bearing contact from spatial conjugate curves
Authors: Tan Rulong , Chen Bingkui , Peng Changyan , Liang Dong , Xiang Dongyun
Published: December 2015

This paper aims at obtaining the mathematical model of the general spiral bevel gears of local bearing contact from spatial conjugate curve theory. Differential geometry and gearing kinematics are introduced to derive this model. Meshing-correctly conditions are set in the theoretical derivation process. The final model is represented in the form of equations and inequalities. According to the arguments in this paper, a process of designing the tooth surface of spiral bevel gears of local bearing is proposed. Based on this process, the numerical example of a pair of these gears with specific profiles is represented by applying the finite element analysis. Results show that the magnitudes of the deviations between theoretical contact points and real contact points are small. Therefore, the results agree with the mathematical model of the spiral bevel gears of local bearing contact in this paper.
Experimental and numerical study on formation mechanism of linear macro-segregation in low-pressure die casting of Al–Cu–Mn–Ti Alloy
Authors: Wang Ye , Wu Shiping , Xue Xiang , Chen Ruirun , Zhang Jianbing , Xiao Wenfeng
Published: December 2015

The formation mechanism of linear macro-segregation in Al–Cu–Mn–Ti alloy cylindrical shell casting was studied by characterizing samples by X-ray detection, microscopic examinations, composition analysis, and simulation of the heat transfer of Al–Cu–Mn–Ti alloy cylindrical shell casting in the solidification process. Numerical and experimental results indicated that linear macro-segregation always occurred in the portion of casting connected with the slit gating system, because of the great hot tearing tendency, the hot cracks formed could be fed by the melt through the slit gating system with an excellent temperature gradient and feeding angle. According to significant effect of floatation of lower density α-Al grains, the solute gradient was formed along the vertical direction of the slit gating system. The hot cracks near the bottom of casting were fed by melt with high concentration of Cu and so, they were cicatrized by the eutectic structure/α-Al + Al2Cu at a temperature of 548℃.
Sanctions and Alternate Markets
Authors: Peksen Dursun , Peterson Timothy M.
Published: December 2015

Although much research has examined how third parties might affect the success of economic sanctions, scant research has considered the extent to which potential—rather than realized—alternate markets affect strategic behavior between sanctioning (sender) and target states prior to sanction use. We argue that the sender is more likely to threaten or impose sanctions against a potential target with higher trade dependence on the sender, but only under the condition that the target’s ability to redirect lost trade to third parties is low. As the target’s ability to redirect lost trade increases, the sender is less likely to use sanctions because it expects that the target could mitigate the intended costs of the coercion more easily. We capture potential alternate markets using a measure of the total economic capabilities held by the target’s allies, finding support for our expectations in statistical tests using data on U.S. sanctions spanning 1950 to 2005. Our results affirm the importance of accounting for third parties and alternate markets as factors influencing the strategic behavior associated with the use of economic coercion.
Defining the impact of the use of granulocyte colony stimulating factors on the incidence of chemotherapy-induced neutropenia in patients with gynecologic malignancies
Authors: Julius Justin M , Hammerstrom Aimee , Wei Caimiao , Rajesh Raeshmma , Bodurka Diane C , Kurian Shiney , Smith Judith A
Published: December 2015

Purpose

The objectives of this study were to characterize the incidence of chemotherapy-induced neutropenia (CIN) and febrile neutropenia (FN) with specific chemotherapy agents commonly used in the treatment of gynecologic malignancies, as well as defining the impact of granulocyte colony stimulating factors (G-CSF) on the prevention of CIN and FN in this patient population.

Methods

This retrospective analysis was conducted from a database of 635 gynecologic cancer patients who received chemotherapy between 1 September 2007 and 31 August 2008. A logistic regression analysis was conducted to determine the impact of potential covariates on the overall incidence of CIN.

Results

Overall, 28.3% of patients experienced CIN with one or more cycles chemotherapy, and 13.1% had treatment delays or dose reduction associated with CIN. The use of G-CSF prior to administration of chemotherapy resulted in a decrease in the incidence of CIN from 29.8% to 19.6% compared to no G-CSF use. No difference was observed in number of treatment delays or dose reductions in the 46 (7.2%) of gynecologic cancer patients that received G-CSF prophylaxis. Multivariate analysis found that both age and the number of current cycles jointly may predict risk of CIN.

Conclusions

Patients with gynecologic malignancies appear to be at a higher risk of development of neutropenia when treated with chemotherapy. The proactive use of G-CSF did decrease the risk of CIN by over 30%. Prospective study is warranted to determine the impact of G-CSF to reduce CIN in patients with gynecologic malignancies receiving chemotherapy.
Literacy and Numeracy Underachievement in Boys and Girls With ADHD
Authors: Silva Desiree , Colvin Lyn , Glauert Rebecca , Stanley Fiona , Srinivas Jois Ravisha , Bower Carol
Published: December 2015

Objective: To determine literacy and numeracy outcomes, among children with and without ADHD by gestational age and gender. Method: De-identified linked population data from the Western Australian Monitoring of Drug Dependence Systems, Western Australian Literacy and Numeracy Assessment database, and the Midwives Notification System used information on 6,819 children with ADHD compared with 14,451 non-ADHD children. Results: Twenty-three percent of boys and 28% of girls with ADHD had numeracy scores below the benchmark in School Year 3, compared with 11% of children without ADHD. These differences were also evident in reading, writing, and spelling through primary school. Children with ADHD and reduced gestational age were at a greater risk of not meeting numeracy and reading benchmarks, compared with children born at term. Conclusion: Children with ADHD are disadvantaged from an early age in key areas of learning, and this risk increased with reduction in gestational age at birth.
Effect of Anodal and Cathodal Transcranial Direct Current Stimulation on DLPFC on Modulation of Inhibitory Control in ADHD
Authors: Soltaninejad Zahra , Nejati Vahid , Ekhtiari Hamed
Published: December 2015

Objective: The purpose of this study was to improve the inhibitory control functions through transcranial direct current stimulation (tDCS) in adolescents with ADHD symptoms. Method: Twenty high school students with ADHD symptoms participated in this single-blinded, crossover, sham-controlled study. All the participants were tested during the application of Stroop and Go/No-Go tasks that is used to measure inhibitory control, using 1.5 mA of tDCS for 15 min over the left dorsolateral prefrontal cortex (DLPFC). Results: Anodal stimulation on left DLPFC had no effect on interference inhibition during the Stroop task and increased the proportion of correct responses in the “Go stage” of the Go/No-Go test compared with sham condition. Cathodal stimulation on the left DLPFC increased the inhibition accuracy in the inhibition stage during Go/No-Go task in comparison with sham. Conclusion: tDCS over the left DLPFC of adolescents who suffer from ADHD symptoms can improve inhibitory control in prepotent response inhibition.
Critical event recognition: An extended view of reflective learning
Authors: Lindh Ida , Thorgren Sara
Published: December 2015

This inductive case study extends existing reflective learning theory by introducing the concept of critical event recognition. We define this as the cognitive process through which individuals conclude that they are facing a critical learning point that demands a change of thoughts and actions. Extant theory has described reflection and learning as processes of interaction among an individual’s various experiences and has emphasized that critical events are important for these processes. Yet, theory has largely ignored how learners develop task-specific cognitions from such critical events when they lack previous task-specific experiences to which they can relate the reflection. This study proposes an extended perspective on reflective learning by shedding light on event recognition and by illustrating how cognitive development may progress when the individual has little prior experience with which to integrate the reflection from critical events.
The research on wing sail of a land-yacht robot
Authors: Xie Shaorong , Chen Jiqing , Li Hengyu , Luo Jun , Pu Huayan , Peng Yan
Published: December 2015

A wind-driven land-yacht robot which will be applied in polar expedition is presented in this article. As the main power of robot is provided by wing sail, improving the efficiency of wing sail is the key for its motion. Wing sail is composed of airfoil, so airfoil theory is researched first, and then several airfoils and their aerodynamic performance are compared, and a high-efficiency airfoil is selected. After that, overturning torque and start wind speed of robot are analyzed to determine the size of the wing sail. At last, the wing sail is manufactured and checked, and it is tested by start wind speed experiments, running speed experiments, steering motion, and obstacle avoidance experiments. The minimum start wind speed is 6 m/s. When wind speed is 10.3 m/s and angle of attack is 90°, running velocity of robot is 1.285 m/s. A land-yacht robot can run steering motion well and avoid obstacle to the target. The result shows that wing sail satisfies the motion requirement of land-yacht robot.
Career Aspirations and Emotional Adjustment of Chinese International Graduate Students
Authors: Cozart Deanna L. , Rojewski Jay W.
Published: December 2015

There are more Chinese student-scholars than any other group of international students studying in the United States. Despite this, there are relatively few studies that have focused on specific educational needs and required career support services for Chinese international students. This exploratory study was conducted to determine the relationship between career aspirations and emotional adjustment of Chinese international students. Results from Chinese students were compared with those of students from the United States. Relationships between the career aspirations and emotional adjustment of Chinese and U.S. students did not reveal statistically significant differences. However, regression analysis indicated that social stress was a statistically significant predictor of career aspirations for U.S. students. Chinese and U.S. students were more alike than different on career aspirations and emotional adjustment, and observed educational similarities appeared to outweigh any cultural differences that existed when determining these outcomes.
Nascent osteoblast matrix inhibits osteogenesis of human mesenchymal stem cells in vitro
Authors: Kolf Catherine M. , Song Lin , Helm Jeannine , Tuan Rocky S.
Published: December 2015

Introduction

Adult mesenchymal stem cells (MSCs) are considered promising candidates for cell-based therapies. Their potential utility derives primarily from their immunomodulatory activity, multi-lineage differentiation potential, and likely progenitor cell function in wound healing and repair of connective tissues. However,in vitro, MSCs often senesce and spontaneously differentiate into osteoblasts after prolonged expansion, likely because of lack of regulatory microenvironmental signals.In vivo, osteoblasts that line the endosteal bone marrow surface are in close proximity to MSCs in the marrow stroma and thus may help to regulate MSC fate.

Methods

We examined here how osteogenic differentiation of MSCsin vitrois affected by exposure to osteoblastic cells (OBCs). Human bone marrow MSCs were exposed to OBCs, derived by induced osteogenic differentiation of MSCs, either directly in contact co-cultures, or indirectly to OBC-conditioned medium or decellularized OBC extracellular matrix (ECM).

Results

Our results showed that OBCs can act as negative regulators of MSC osteogenesis. mRNA expression profiling revealed that OBCs did not affect MSC osteogenesis in direct contact cultures or via secreted factors. However, seeding MSCs on decellularized OBC ECM significantly decreased expression of several osteogenic genes and maintained their fibroblastic morphologies. Proteomic analysis identified some of the candidate protein regulators of MSC osteogenesis.

Conclusions

These findings provide the basis for future studies to elucidate the signaling mechanisms responsible for osteoblast matrix-mediated regulation of MSC osteogenesis and to better manipulate MSC fatein vitroto minimize their spontaneous differentiation.
Fluid Volume Expansion and Depletion in Hemodialysis Patients Lack Association with Clinical Parameters
Authors: Kalainy Sylvia , Reid Ryan , Jindal Kailash , Pannu Neesh , Braam Branko
Published: December 2015

Background:

Achievement of normal volume status is crucial in hemodialysis (HD), since both volume expansion and volume contraction have been associated with adverse outcome and events.

Objectives:

The objectives of this study are to assess the prevalence of fluid volume expansion and depletion and to identify the best clinical parameter or set of parameters that can predict fluid volume expansion in HD patients.

Design:

This study is cross-sectional.

Setting:

This study was conducted in three hemodialysis units.

Patients:

In this study, there are 194 HD patients.

Methods:

Volume status was assessed by multifrequency bio-impedance spectroscopy (The Body Composition Monitor, Fresenius) prior to the mid-week HD session.

Results:

Of all patients, 48 % ( n = 94) were volume-expanded and 9 % of patients were volume-depleted ( n = 17). Interdialytic weight gain was not different between hypovolemic, normovolemic, and hypervolemic patients. Fifty percent of the volume-expanded patients were hypertensive. Paradoxical hypertension was very common (31 % of all patients); its incidence was not different between patient groups. Intradialytic hypotension was relatively common and was more frequent among hypovolemic patients. Multivariate regression analysis identified only four predictors for volume expansion (edema, lower BMI, higher SBP, and smoking). None of these parameters displayed both a good sensitivity and specificity.

Limitations:

The volume assessment was performed once.

Conclusions:

The study indicates that volume expansion is highly prevalent in HD population and could not be identified using clinical parameters alone. No clinical parameters were identified that could reliably predict volume status. This study shows that bio-impedance can assist to determine volume status. Volume status, in turn, is not related to intradialytic weight gain and is unable to explain the high incidence of paradoxical hypertension.
Three-dimensional imaging of a Ag-Au-rich epithermal system in British Columbia, Canada, using airborne z-axis tipper electromagnetic and ground-based magnetotelluric data
Authors: Hübert Juliane , Lee Benjamin M. , Liu Lijuan , Unsworth Martyn J. , Richards Jeremy P. , Abbassi Bahman , Cheng Li Zhen , Oldenburg Douglas W. , Legault Jean M. , Rebagliati Mark
Published: December 2015

We have evaluated results from a study combining airborne z-axis tipper electromagnetic (ZTEM) and ground-based magnetotelluric (MT) data to image an epithermal system in British Columbia. The spatially coincident use of these two methods allowed for a direct comparison of both data sets in the overlapping frequency band and showed that both measurements were consistent. Inversion of just the ZTEM data suffered from the lack of electric field amplitude information, which could be provided by the MT data. Three-dimensional inversion modeling of the two individual data sets was performed. Models of electrical resistivity derived from both data sets were consistent and could be correlated with the geological and structural setting of the mineralization. Gold is associated with disseminated pyrite and marcasite in quartz-sericite-altered felsic volcanic rocks and intrusions, especially near the contact with mafic volcanic rocks and a late diorite intrusion. The quartz-sericite alteration yields a conductivity anomaly, relative to the more resistive mafic country rocks. Although ZTEM and MT do not possess the resolution of the geologic model derived from borehole data, our model agrees well with a regional assessment of the deposit.
Optimal control policy for a Brownian inventory system with concave ordering cost
Authors: Yao Dacheng , Chao Xiuli , Wu Jingchen
Published: December 2015

In this paper we consider an inventory system with increasing concave ordering cost and average cost optimization criterion. The demand process is modeled as a Brownian motion. Porteus (1971) studied a discrete-time version of this problem and under the strong condition that the demand distribution belongs to the class of densities that are finite convolutions of uniform and/or exponential densities (note that normal density does not belong to this class), an optimal control policy is a generalized (s, S) policy consisting of a sequence of (si, Si). Using a lower bound approach, we show that an optimal control policy for the Brownian inventory model is determined by a single pair (s, S).
Tollbooth tandem queues with infinite homogeneous servers
Authors: Chao Xiuli , He Qi-Ming , Ross Sheldon
Published: December 2015

In this paper we analyze a tollbooth tandem queueing problem with an infinite number of servers. A customer starts service immediately upon arrival but cannot leave the system before all customers who arrived before him/her have left, i.e. customers depart the system in the same order as they arrive. Distributions of the total number of customers in the system, the number of departure-delayed customers in the system, and the number of customers in service at time t are obtained in closed form. Distributions of the sojourn times and departure delays of customers are also obtained explicitly. Both transient and steady state solutions are derived first for Poisson arrivals, and then extended to cases with batch Poisson and nonstationary Poisson arrival processes. Finally, we report several stochastic ordering results on how system performance measures are affected by arrival and service processes.
Conditional Sojourn times and the volatility of payment schemes for bandwidth sharing in packet networks
Authors: Guillemin Fabrice M. , Mazumdar Ravi R.
Published: December 2015

Predictability of revenue and costs to both operators and users is critical for payment schemes. We study the issue of the design of payment schemes in networks with bandwidth sharing. The model we consider is a processor sharing system that is accessed by various classes of users with different processing requirements or file sizes. The users are charged according to a Vickrey–Clarke–Groves mechanism because of its efficiency and fairness when logarithmic utility functions are involved. Subject to a given mean revenue for the operator, we study whether it is preferable for a user to pay upon arrival, depending on the congestion level, or whether the user should opt to pay at the end. This leads to a study of the volatility of payment schemes and we show that opting for prepayment is preferable from a user point of view. The analysis yields new results on the asymptotic behavior of conditional response times for processor sharing systems and connections to associated orthogonal polynomials.
Phylogenetic confidence intervals for the optimal trait value
Authors: Bartoszek Krzysztof , Sagitov Serik
Published: December 2015

We consider a stochastic evolutionary model for a phenotype developing amongstnrelated species with unknown phylogeny. The unknown tree is modelled by a Yule process conditioned onncontemporary nodes. The trait value is assumed to evolve along lineages as an Ornstein-Uhlenbeck process. As a result, the trait values of thenspecies form a sample with dependent observations. We establish three limit theorems for the sample mean corresponding to three domains for the adaptation rate. In the case of fast adaptation, we show that for largenthe normalized sample mean is approximately normally distributed. Using these limit theorems, we develop novel confidence interval formulae for the optimal trait value.
The extinction time of a subcritical branching process related to the SIR epidemic on a random graph
Authors: Windridge Peter
Published: December 2015

We give an exponential tail approximation for the extinction time of a subcritical multitype branching process arising from the SIR epidemic model on a random graph with given degrees, where the type corresponds to the vertex degree. As a corollary we obtain a Gumbel limit law for the extinction time, when beginning with a large population. Our contribution is to allow countably many types (this corresponds to unbounded degrees in the random graph epidemic model, as the number of vertices tends to∞). We only require a second moment for the offspring-type distribution featuring in our model.
Financial Innovation, Collateral, and Investment
Authors: Fostel Ana , Geanakoplos John
Published: December 2015

Financial innovations that change how promises are collateralized affect prices and investment, even in the absence of any change in fundamentals. In C-models, the ability to leverage an asset always generates overinvestment compared to Arrow-Debreu. Credit Default Swaps always leads to underinvestment with respect to Arrow-Debreu, and in some cases even robustly destroy competitive equilibrium. The need for collateral would seem to cause under-investment. Our analysis illustrates a countervailing force: goods that serve as collateral yield additional services and can therefore be over-valued and over-produced. In models without cash flow problems there is never marginal underinvestment on collateral. (JEL D52, D86, D92, E44, G01, G12, R31)
Optimal Intermediary Rents
Authors: Schroth Josef
Published: December 2015

This paper studies a dynamic production economy with financial intermediation. It is assumed that claims held on intermediaries cannot be fully enforced such that intermediation is subject to intermediary equity requirements. It is shown that competitive equilibria are not constrained efficient whenever the aggregate amount of intermediary equity in the economy is low enough to limit production. Specifically, a constrained social planner can achieve a Pareto improvement by creating long-term rents for intermediaries, which immediately reduces intermediary equity requirements. The constrained-efficient allocation can be implemented by a positive tax on future intermediary activity. (JEL D21, D82, D86, G21, G28)
E-satisfação em compras de alto e baixo envolvimento
Authors: Ceribeli Harrison Bachion , Merlo Edgard Monforte
Published: December 2015

Esta pesquisa teve como objetivo identificar e analisar os elementos associados às experiências de compra online que influenciam a e-satisfação em compras de alto e baixo envolvimento no comércio eletrônico. Foi realizado um levantamento de campo, cuja amostra foi composta por 720 e-consumidores. Para análise dos dados referentes a compras de alto envolvimento, utilizou-se a Modelagem de Equações Estruturais; para análise dos dados referentes a compras de baixo envolvimento, utilizaram-se a Análise Fatorial Exploratória e a Análise de Regressão Múltipla. Constatou-se que a conveniência, a política de trocas e devoluções da empresa e a qualidade da entrega influenciam a e-satisfação em compras de alto envolvimento, enquanto a inovação percebida no website, os preços e a estética do website influenciam o fluxo online, que, por sua vez, influencia a e-satisfação. Complementarmente, constatou-se que a qualidade da entrega, as informações disponíveis no website e a estrutura de atendimento influenciam a e-satisfação em compras de baixo envolvimento.
O estado da arte na articulação entre os temas cultura organizacional e inovação
Authors: Fernandes Roberto Fabiano , Lemos Dannyela Da Cunha , Hoffmann Micheline Gaia , Feuerschütte Simone Ghisi
Published: December 2015

Este trabalho objetivou caracterizar o estado da arte na produção acadêmica que articula os temas inovação e cultura organizacional sob um enfoque prescritivo, ou seja, as abordagens ou propostas voltadas ao gerenciamento da cultura com vistas à inovação. Além disso, ressalta-se que este trabalho segue uma abordagem qualitativa e que os resultados aqui apresentados fazem parte da etapa de pré-campo de um projeto de pesquisa chamado – Núcleo de Apoio a Gestão da Inovação. Para tanto, foi realizada uma revisão bibliográfica sistemática com bibliometria, com o propósito de investigar estudos que empregaram modelos/instrumentos de pesquisa predominantes na literatura, no sentido de confirmar as suas contribuições. Os resultados permitiram a elaboração de um portfólio de 22 artigos, dos quais sete tratavam do Competing Values Framework (CVF), de Cameron e Quinn (1999, 2006, 2011).
Perfil dos frequentadores das academias ao ar livre da cidade de Pelotas - RS
Authors: Iepsen Alice , Silva Marcelo
Published: December 2015

O objetivo do estudo foi verificar o perfil dos frequentadores das academias ao ar livre (AAL) localizadas no perímetro urbano de Pelotas-RS. Todos indivíduos adultos com 20 anos ou mais de idade que utilizaram algum dos aparelhos das três AAL entre os meses de outubro e dezembro de 2014 foram entrevistados. As entrevistas foram realizadas nas segundas-feiras, terças-feiras e sábados, nos horários de maior fluxo de utilização. Para coleta de dados foi utilizado um questionário contendo questões demográficas, socioeconômicas, comportamentais, de saúde e relativas à utilização das AAL. Foi realizada a análise descritiva das variáveis por meio do programa Stata 13.0. Ao final do estudo, foram entrevistados 323 indivíduos. A maior frequência de usuários das AAL foi do sexo feminino (65,3%), de cor da pele branca (83,6%), casados ou vivendo com companheiro (61,9%), com 50 anos ou mais de idade (61,3%), com renda acima de 1319 reais (78,6%), com o ensino médio ou superior completos (69,3%), Índice de Massa Corporal (IMC) relativo à sobrepeso e obesidade (74,9%), não fumantes atuais (91,1%) e suficientemente ativos no lazer (77,7%). Apesar de 45,8% dos usuários perceberem sua saúde como sendo boa, 48,3 relataram ter pressão alta, 10,5% ter diabetes e 64,4% utilizar algum medicamento. Além disso, 19,2% frequentavam a AAL pelo menos três dias por semana, sendo que mais de 80% realizava AF em outro local. Estes resultados devem guiar intervenções para promover o maior uso das AAL e a prática de atividade física realizada nestes locais.
Avaliação da força de extensão do joelho em indivíduos idosos: confiabilidade de um protocolo de teste isocinético
Authors: Martins Wagner , Oliveira Ricardo , Silva Marianne , Santos Tacio , Diniz Leonardo , Carmo Jake , Moreno Ricardo , Bottaro Martim
Published: December 2015

A redução da força muscular pode ser resultado do envelhecimento, sendo considerado um fator de risco para quedas. Objetivou-se analisar a confiabilidade de avaliação do pico de torque isocinético de extensão do joelho em indivíduos idosos. Foram avaliados vinte idosos saudáveis, 10 homens (68.4 ± 6.6 anos) e 10 mulheres (69.8 ± 6.7 anos) que participaram de duas sessões (teste e reteste) com um intervalo de 48 horas. Cada sessão consistiu de uma etapa de aquecimento, seguido de 3 séries de 4 contrações de extensão concêntrica de joelho a 60º/s e de mais 3 séries de 4 contrações de extensão concêntrica de joelho a 120º/s. Não foi utilizado qualquer período de familiarização com o protocolo de avaliação. Para fins de análise foi considerando o maior pico de torque entre as 3 séries de 4 contrações nas respectivas velocidades investigadas. Para análise da confiabilidade absoluta e relativa foram utilizados o coeficiente de correlação intraclasse (ICC), o erro padrão da medida (SEM) e o método de representação gráfica de Bland-Altman. Os resultados da análise da confiabilidade relativa demonstraram ICC de 0,94 (60º/s) e de 0,96 (120º/s). Em relação à confiabilidade absoluta, o erro sistemático foi de 1,4 Nm (60º/s) e de 0,8 Nm (120º/s), e o erro aleatório foi de 15,1 Nm (60º/s) e de 12,1 Nm (120º/s). A avaliação do pico de torque de extensão do joelho em idosos saudáveis apresentou confiabilidade relativa e absoluta aceitável demonstrando que a ausência de familiarização não comprometeu a confiabilidade do teste de força muscular de idosos medido com equipamento isocinético.
Teacher and Parent Views on The Instruction of 5th Grade Students by Branch Teachers in The 4+4+4 Education System
Authors: Yildizhan Yusuf Hayri
Published: December 2015

The objective of this study is to examine the teacher and parent views on the instruction of 5th grade students by branch teachers. This study is designed according to the phenomenology design and uses qualitative data. In order to collect data, open- ended questions were asked to 18 teachers and 16 parents of 5th grade students on the subject, and the responses were analyzed. According to the results of the study, for parents, the disadvantageous aspects of instruction of 5th grade students by branch teachers are that the students could not express themselves in the new class, there is no one knowing and monitoring them closely in the new class and students have difficulty in doing the performance homework. On the other hand, advantageous aspects for students according to parents are that branch teachers give instruction as they have command on the subject and students take multiple teachers as models. The study found the disadvantageous aspects for teachers as having difficulty in completing the curriculum, following homework and maintaining classroom discipline.
Learning Mathematics in English at Basic Schools in Ghana: A Benefit or Hindrance?
Authors: Fredua-Kwarteng Eric , Ahia Francis
Published: December 2015

Facilitating effective mathematics learning and higher mathematics achievement have long been recognized as a key to the scientific and technological advancement of the African continent. While the central role that language proficiency plays in mathematics teaching and learning has received an overwhelming research attention in the literature over the past two decades, this is not the case among African policy-makers and political leaders. Drawing mainly from our professional experiences as mathematics educators and from the international research literature, our primary intent in this paper is to answer this question: How does the learning of mathematics in English at the basic school level help or hinder students’ mathematical proficiency? To answer this question, the paper is organized as follows. The first part, the introduction, gives a brief overview of the language of learning and teaching in Africa. The second part describes the method and conceptual framework undergirding the research. In the third section, we have analyzed the effects of mathematics learning and teaching through English for basic students whose mother tongue is a Ghanaian language. The conclusion offers four recommendations for developing and improving the mathematics proficiency of students in basic schools.
European Teachers’ Technological Pedagogical Content Knowledge (TPCK) and Educational Use of Web Technologies
Authors: Baris Mehmet Fatih
Published: December 2015

Several studies have been conducted on technological, pedagogical content knowledge and web-based education. In this study, the Technological Pedagogical Content Knowledge and Educational Use of Web Technologies (TPCK-W) were analyzed in addition to the self-efficacy and attitudes of 33 teachers from eight different branches carrying out their duties in 19 countries of the European Union (EU). In this study, the Technological Pedagogical Content Knowledge-Web (TPCK-W) Survey developed by Lee, Tsai, and Chan was used. The data obtained statistics software was analyzed using SPSS for Windows 17.0 statistics software. As a result of the analysis, it was revealed that TPCK-W self-efficacy of teachers carrying out their duties in EU countries was high and their attitudes were positive; and age, experience, and gender did not affect their TPCK-W self-efficacy and attitudes. Moreover, participants’ general web attitudes changed positively, depending on their web communication, web content, and pedagogical use of the web.
GROUP INTERVAL WEIGHTS BASED ON CONJUNCTION APPROXIMATION OF INDIVIDUAL INTERVAL WEIGHTS
Authors: Entani Tomoe
Published: December 2015

The individual and group decisions in this study are denoted as the normalized interval weights of alternatives as in Interval AHP. It assumes that a decision maker uses crisp values in the interval weights in giving comparisons. The interval weights reflect uncertainty in a decision maker’s mind. Then, the group interval weight is obtained as a conjunction approximation of the individual interval weights. For a consensus, the group interval weight is obtained so as to intersect with all the individual interval weights. In other words, the group interval weight has something in common with each individual interval weight. The group decision depends on how much the decision makers are satisfied or dissatisfied with it. The satisfaction of a decision maker is measured by the ranges of the group interval weights which s/he can support. Similarly, the decision maker’s dissatisfaction is defined by the ranges which are out of his/her decision. It is better to maximize the satisfaction and simultaneously to minimize the dissatisfaction. However, there is a trade-off between these two objectives. In the proposed model, the importance of the satisfaction or dissatisfaction is given. Then, the decision makers find not only the group decision but also their satisfaction and dissatisfaction with it. 