bluuebunny/crossref_metadata_2025_split huggingface dataset:
Generalized Semiparametric Varying-Coefficient Model for Longitudinal Data with Applications to Adaptive Treatment Randomizations
Authors: Qi Li , Sun Yanqing , Gilbert Peter B. 
Published: December 2016

Summary
This article investigates a generalized semiparametric varying-coefficient model for longitudinal data that can flexibly model three types of covariate effects: time-constant effects, time-varying effects, and covariate-varying effects. Different link functions can be selected to provide a rich family of models for longitudinal data. The model assumes that the time-varying effects are unspecified functions of time and the covariate-varying effects are parametric functions of an exposure variable specified up to a finite number of unknown parameters. The estimation procedure is developed using local linear smoothing and profile weighted least squares estimation techniques. Hypothesis testing procedures are developed to test the parametric functions of the covariate-varying effects. The asymptotic distributions of the proposed estimators are established. A working formula for bandwidth selection is discussed and examined through simulations. Our simulation study shows that the proposed methods have satisfactory finite sample performance. The proposed methods are applied to the ACTG 244 clinical trial of HIV infected patients being treated with Zidovudine to examine the effects of antiretroviral treatment switching before and after HIV develops the T215Y/F drug resistance mutation. Our analysis shows benefits of treatment switching to the combination therapies as compared to continuing with ZDV monotherapy before and after developing the 215-mutation.
Virtual forms, actual effects: how amplifying student voice through digital media promotes reflective practice and positions students as pedagogical partners to prospective high school and practicing college teachers
Authors: Cook‐Sather Alison 
Published: December 2016

AbstractDigital media have unique potential to amplify student voice in both high school teacher preparation and academic development for college faculty. This paper applies narrative analysis to participant descriptions of how three uses of digital media amplify student voice in the context of a single higher education consortium: (1) high school students and prospective high school teachers use email to engage in dialogue as part of a larger project within the consortium's secondary teacher preparation program, (2) undergraduate student consultants use visual mapping technology as a classroom observation tool through one of the consortium's academic development programs for college faculty and (3) graduate and undergraduate students, faculty and staff engaged in pedagogical partnerships within and beyond this consortium use on an online platform to publish reflective essays on their collaborative work. Amplifying student voice through these uses of digital media has the following actual effects: it creates the possibility for exchanges between students and teachers across space and time; it supports the development of reflective practice; and it encourages the embrace of a partnership approach to teaching and learning.
Orchestrating 21st century learning in higher education: A perspective on student voice
Authors: Hämäläinen Raija , Kiili Carita , Smith Blaine E. 
Published: December 2016

AbstractFor universities to meet the 21st‐century learning needs of today's students, it is important they allow students to take an active role in developing pedagogy and sharing their perspective. This paper introduces design‐based research aiming to develop a pedagogic approach to support technology‐enhanced learning practices at the university level with the focus on teacher orchestration of learning activities and student voice. Drawing from the perspectives of teachers and students who participated in a course focused on learning and 21st‐century competencies, four main elements indicating student voice and technology‐enhanced pedagogy are presented: increased interaction among university communities, teacher orchestration, technology and collaborative learning. Enabling and hindering factors related to student voice are presented for each element.
Evaluating a blended degree program through the use of the NSSE framework
Authors: Vaughan Norman , Cloutier David 
Published: December 2016

AbstractThe purpose of this student‐faculty partnership research study was to evaluate the effectiveness of a blended four‐year Bachelor of Education Elementary Program at a Canadian university using the National Survey of Student Engagement (NSSE) framework. Data was collected from the first graduating cohort of students from the B.Ed. program in partnership with four Undergraduate Student Research Assistants (USRA). The students in this study completed online surveys and participated in focus groups at the end of their first and fourth years in the program. The study participants provided recommendations for improving the quality of the program based on the five NSSE benchmarks and the use of digital technologies. The main recommendations that emerged from this study were that student and faculty interactions, outside of the classroom, could be enhanced through the use of web‐based conferencing tools to support “virtual” office hours. Course assignments that incorporate peer mentoring activities through the use of social media applications could provide richer opportunities for active and collaborative learning. Creating more intentional connections between academic coursework and field placements through the use of Google applications could help to strengthen the relationship between theory and practice in the program. Enriching educational experiences could be expanded through the use of social media applications to promote and communicate student led academic and social events. A supportive campus environment could be improved by the development of a digital “road map” and co‐curricular record for the program.
Iron overload across the spectrum of non‐transfusion‐dependent thalassaemias: role of erythropoiesis, splenectomy and transfusions
Authors: Porter John B. , Cappellini Maria Domenica , Kattamis Antonis , Viprakasit Vip , Musallam Khaled M. , Zhu Zewen , Taher Ali T. 
Published: December 2016

SummaryNon‐transfusion‐dependent thalassaemias (NTDT) encompass a spectrum of anaemias rarely requiring blood transfusions. Increased iron absorption, driven by hepcidin suppression secondary to erythron expansion, initially causes intrahepatic iron overload. We examined iron metabolism biomarkers in 166 NTDT patients with β thalassaemia intermedia (n = 95), haemoglobin (Hb) E/β thalassaemia (n = 49) and Hb H syndromes (n = 22). Liver iron concentration (LIC), serum ferritin (SF), transferrin saturation (TfSat) and non‐transferrin‐bound iron (NTBI) were elevated and correlated across diagnostic subgroups. NTBI correlated with soluble transferrin receptor (sTfR), labile plasma iron (LPI) and nucleated red blood cells (NRBCs), with elevations generally confined to previously transfused patients. Splenectomised patients had higher NTBI, TfSat, NRBCs and SF relative to LIC, than non‐splenectomised patients. LPI elevations were confined to patients with saturated transferrin. Erythron expansion biomarkers (sTfR, growth differentiation factor‐15, NRBCs) correlated with each other and with iron overload biomarkers, particularly in Hb H patients. Plasma hepcidin was similar across subgroups, increased with >20 prior transfusions, and correlated inversely with TfSat, NTBI, LPI and NRBCs. Hepcidin/SF ratios were low, consistent with hepcidin suppression relative to iron overload. Increased NTBI and, by implication, risk of extra‐hepatic iron distribution are more likely in previously transfused, splenectomised and iron‐overloaded NTDT patients with TfSat >70%.
A qualitative perspectival review of the Australian and New Zealand Urology Education and Training program
Authors: Rashid Prem 
Published: December 2016

ObjectivesTo conduct a prospective, qualitative review to explore the challenges associated with the delivery of current and future high‐quality urological training, and to report the reflective considerations and opinions of leaders in the Australian and New Zealand (ANZ) urological surgical training programme.MethodsEthics‐approved semi‐structured, template‐based, qualitative interview techniques were used to evaluate key aspects of the current urology training programme. Those interviewed were senior office bearers and management staff involved in the Surgical Education and Training (SET) programme. Interviews were recorded and transcribed for analysis. Grounded theory was used with thematic analysis to assess the data. The initial impression given by the data was used to identify critical codes and themes, which were then developed and abstracted to bring together global concepts.ResultsTwenty‐four extracted themes were outlined. The recent evolution of urology training was documented as the pathway into training has changed several times over the years. The changes in the programme have led to concern from opinion leaders that the ‘pendulum has swung too far.’ Surgical teachers will only truly develop if appropriate resources are allocated. This can be achieved by making up‐skilling courses accessible, relevant and, ultimately, a part of the accreditation of training posts. Management of underperforming trainees is challenging and continues to occupy a significant and disproportionate allocation of resources. Early constructive intervention is very important to avoid unnecessary escalation of complex issues and the resultant inter‐personal consequences.ConclusionsThe ANZ SET urology programme began, like many of the other surgical specialties, from humble beginnings. It is now a mature programme, but there remain areas needing improvement. The workload of supervisors and office bearers has been increasing and the management of underperforming trainees takes time and resources away from progress in educational development. Progressive steps can be instituted to improve supervisor up‐skilling, and structural changes can be made to ensure that office bearers can continue to undertake their valuable work without undue pressure and stress. Some of this will involve separating innovation in education and training from day‐to‐day trainee management.
THE OPTIMAL RISK CHOICE OF COOPERATIVE AND NONCOOPERATIVE R&D IN DUOPOLY WITH SPILLOVERS
Authors: Xing Mingqing 
Published: December 2016

ABSTRACTThis study examines the R&D risk choice in a duopoly market with technology spill overs. The firms conduct R&D programmes with different degrees of risk but an identical expected outcome and they compete or cooperate in R&D. Findings indicate that, in equilibrium, the R&D risk level decreases in the spill over rate under noncooperative R&D, while it may increase under cooperative R&D. Firms are more likely to engage in higher R&D risks under cooperative R&D than they are under non‐cooperative R&D. Moreover, the equilibrium R&D risk level both under competition and cooperation R&D is always too low from the perspective of social welfare, and the extent of this inefficiency increases with the spill over rate if the size of the spill over is large, but the opposite may occur if the size of the spill over is small.
Reflections on the IPCC and global change science: Time for a more (physical) geographical tradition
Authors: Spencer Thomas , Lane Stuart N. 
Published: December 2016

Key Messages

Single factor climate change metrics, such as global mean temperature increase or global sea level rise, have little meaning for the explanation of landscape scale change.
Global scale analyses struggle to incorporate landscape settings; the role of climatic variability alongside secular change; intrinsic systems feedbacks which modulate external forcing; and spatial and temporal cascades of energy and matter.
The ultimate goal of global change research should be the study of the implications of climate change for human lives and livelihoods and here the geographical tradition can make a significant contribution.
Hierarchical Bucket Queuing for Fine‐Grained Priority Scheduling on the GPU
Authors: Kerbl Bernhard , Kenzel Michael , Schmalstieg Dieter , Seidel Hans‐Peter , Steinberger Markus 
Published: December 2016

AbstractWhile the modern graphics processing unit (GPU) offers massive parallel compute power, the ability to influence the scheduling of these immense resources is severely limited. Therefore, the GPU is widely considered to be only suitable as an externally controlled co‐processor for homogeneous workloads which greatly restricts the potential applications of GPU computing. To address this issue, we present a new method to achieve fine‐grained priority scheduling on the GPU: hierarchical bucket queuing. By carefully distributing the workload among multiple queues and efficiently deciding which queue to draw work from next, we enable a variety of scheduling strategies. These strategies include fair‐scheduling, earliest‐deadline‐first scheduling and user‐defined dynamic priority scheduling. In a comparison with a sorting‐based approach, we reveal the advantages of hierarchical bucket queuing over previous work. Finally, we demonstrate the benefits of using priority scheduling in real‐world applications by example of path tracing and foveated micropolygon rendering.
Effect of Redox‐Modifying Agents on the Activity of Channelrhodopsin‐2
Authors: Wu Bao‐Ming , Leng Tian‐Dong , Inoue Koichi , Li Jun , Xiong Zhi‐Gang 
Published: December 2016

SummaryBackgroundThe algal protein Channelrhodopsin‐2 (ChR2) has been widely used in recent years in optogenetic technique to investigate the functions of complex neuronal networks through minimally invasive and temporally precise photostimulation of genetically defined neurons. However, as with any other new technique, current optogentic approaches have various limitations. In addition, how ChR2 may behave in response to complex biochemical changes associated with various physiological/pathological conditions is largely unknown.AimIn this study, we investigated whether a change in redox state of the cell affects the activity of ChR2 channels.MethodsWhole‐cell patch‐clamp recordings were used to examine the effect of reducing and oxidizing agents on ChR2 currents activated by blue light.ResultsWe show that the reducing agent dithiothreitol (DTT) dramatically potentiates the ChR2 currents in a reversible and concentration‐dependent manner. Glutathione, an endogenous reducing agent, shows a similar effect on ChR2 currents. The oxidizing agent 5,5′‐dithio‐bis‐(2‐nitrobenzoic acid) (DTNB) has no effect on ChR2 currents by itself; however, it completely reverses the potentiating effect of DTT. DTT also causes a shift in the current–voltage relationship by 23 ± 4.31 mV, suggesting a change in ion selectivity.ConclusionTaken together, these data suggest that redox modification of ChR2 plays an important role in its sensitivity to the light stimulation. Our findings not only help for a better understanding of how ChR2 may behave in physiological/pathological conditions where changes in redox state are common, but also provide a new direction for further optimization of this important opsin.
Assessment of mammal reproduction for hunting sustainability through community‐based sampling of species in the wild
Authors: Mayor Pedro , El Bizri Hani , Bodmer Richard E. , Bowler Mark 
Published: December 2016

AbstractWildlife subsistence hunting is a major source of protein for tropical rural populations and a prominent conservation issue. The intrinsic rate of natural increase. (rmax) of populations is a key reproductive parameter in the most used assessments of hunting sustainability. However, researchers face severe difficulties in obtaining reproductive data in the wild, so these assessments often rely on classic reproductive rates calculated mostly from studies of captive animals conducted 30 years ago. The result is a flaw in almost 50% of studies, which hampers management decision making. We conducted a 15‐year study in the Amazon in which we used reproductive data from the genitalia of 950 hunted female mammals. Genitalia were collected by local hunters. We examined tissue from these samples to estimate birthrates for wild populations of the 10 most hunted mammals. We compared our estimates with classic measures and considered the utility of the use ofrmaxin sustainability assessments. For woolly monkey (Lagothrix poeppigii) and tapir (Tapirus terrestris), wild birthrates were similar to those from captive populations, whereas birthrates for other ungulates and lowland‐paca (Cuniculus paca) were significantly lower than previous estimates. Conversely, for capuchin monkeys (Sapajus macrocephalus), agoutis (Dasyprocta sp.), and coatis (Nasua nasua), our calculated reproductive rates greatly exceeded often‐used values. Researchers could keep applying classic measures compatible with our estimates, but for other species previous estimates ofrmaxmay not be appropriate. We suggest that data from local studies be used to set hunting quotas. Our maximum rates of population growth in the wild correlated with body weight, which suggests that our method is consistent and reliable. Integration of this method into community‐based wildlife management and the training of local hunters to record pregnancies in hunted animals could efficiently generate useful information of life histories of wild species and thus improve management of natural resources.
Hybrid approaches for detecting credit card fraud
Authors: Kültür Yiğit , Çağlayan Mehmet Ufuk 
Published: December 2016

AbstractAs a natural consequence of the multibillion dollar annual losses incurred as a result of credit card fraud, banks attach great importance to credit card fraud detection. In this paper, we proposed the use of six known models, namely, decision tree, random forest, Bayesian network, Naïve Bayes, support vector machine, and K* models, to form an ensemble for the detection of credit card fraud. We focused on the voting mechanisms used by the ensemble and proposed optimistic, pessimistic, and weighted voting strategies. The proposed model is called optimistic, pessimistic, and weighted voting in an ensemble of models. A dataset of real credit card transactions from a leading bank in Turkey was used to evaluate the performance of optimistic, pessimistic, and weighted voting in an ensemble of models. The results showed that the optimistic voting strategy enables the detection of 31.59% of fraudulent transactions with a false alarm rate of only 0.10%, the pessimistic voting strategy detects 93.92% of fraudulent transactions with a false alarm rate of 13.72%, and the weighted voting strategy detects 64.02% of fraudulent transactions with a false alarm rate of 0.75%. Banks can choose among these voting mechanisms depending on their preferred strategies for fraud detection and desired false alarm rates.
Does dispersal capacity matter for freshwater biodiversity under climate change?
Authors: Bush Alex , Hoskins Andrew J. 
Published: December 2016

Summary

Freshwater ecosystems appear to be sensitive to even minor climatic shifts, and the dendritic nature of rivers as well as patchy distribution of habitats within the terrestrial landscape could limit the ability of species to track suitable climate conditions. Although the importance of dispersal is recognised in theory, there is great uncertainty when quantifying the capacity of species to shift their distributions in response to climate change.

The influence of dispersal capacity on species’ vulnerability to climate change was assessed, using the modelled projections of 527 freshwater species in New South Wales (NSW), Australia. Species’ future ranges were calculated by iteratively identifying colonisation of accessible habitats and loss of suitable habitats within network models. The accessibility of new habitats was based on a given dispersal mode (aquatic, semi‐terrestrial and aerial). The relative impact of dispersal parameters on projected range were evaluated alongside other known sources of uncertainty (climate and emissions scenarios, modelling algorithm and biological group), analysed collectively in a generalised additive mixed‐model, and spatially to locate regions of NSW where projections are associated with the most uncertainty.

Our simulations (1.4 million scenario combinations) suggest at least a third of species will lose more than half their range under climate change. Nevertheless, we emphasise the broad uncertainty that any average encapsulates. Dispersal capacity only had a minor impact on projected range shifts relative to other modelling assumptions but the network‐pathways and maps of uncertainty have value for conservation planning at large scales. Projected range losses initially decreased rapidly as dispersal rates increased but the benefits are reduced above 2–3 km year−1. Taxa restricted to dispersal within the stream network (aquatic) were more vulnerable to climate change than taxa with semi‐terrestrial or aerial dispersal and maps of variation due to dispersal mode and rate indicate where habitat connectivity would be most beneficial.

This study demonstrates the breadth of uncertainties that challenge plans for improving ecosystem adaptation under climate change and highlights where in the landscape those differences were consistent. We emphasise the need for freshwater conservation studies to be ecologically representative, to focus on broad‐scale connectivity for taxa that can move between catchments, and an accessible network of refugia for taxa with more limited dispersal.
Primary productivity of snow algae communities on stratovolcanoes of the Pacific Northwest
Authors: Hamilton T. L. , Havig J. 
Published: December 2016

AbstractThe majority of geomicrobiological research conducted on glacial systems to date has focused on glaciers that override primarily carbonate or granitic bedrock types, with little known of the processes that support microbial life in glacial systems overriding volcanic terrains (e.g., basalt or andesite). To better constrain the role of the supraglacial ecosystems in the carbon and nitrogen cycles, to gain insight into microbiome composition and function in alpine glacial systems overriding volcanic terrains, and to constrain potential elemental sequestration or release through weathering processes associated with snow algae communities, we examined the microbial community structure and primary productivity of snow algae communities on stratovolcanoes in the Cascade Range of the Pacific Northwest. Here, we present the first published values for carbon fixation rates of snow algae communities on glaciers in the Pacific Northwest. We observed varying levels of light‐dependent carbon fixation on supraglacial and periglacial snowfields at Mt. Hood, Mt. Adams, and North Sister. Recovery of abundant 18S rRNA transcripts affiliated with photoautotrophs and 16S rRNA transcripts affiliated with heterotrophic bacteria is consistent with previous studies indicating the majority of primary productivity on snow and ice can be attributed to photoautotrophs. In contrast to previous observations of glacial ecosystems, our geochemical, isotopic, and microcosm data suggest these assemblages are not limited by phosphorus or fixed nitrogen availability. Furthermore, our data indicate these snow algae communities actively sequester Fe, Mn, and P leached from minerals sourced from the local rocks. Our observations of light‐dependent primary productivity on snow are consistent with similar studies in polar ecosystems; however, our data may suggest that DIC may be a limiting nutrient in contrast to phosphorus or fixed nitrogen as has been observed in other glacial ecosystems. Our data underscore the need for similar studies on glacier surfaces and seasonal snowfields to better constrain the role of local bedrock and nutrient delivery on carbon fixation and biogeochemical cycling in these ecosystems.