bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional flower traits and their diversity drive pollinator visitation
Authors: Fornoff Felix , Klein Alexandra‐Maria , Hartig Florian , Benadi Gita , Venjakob Christine , Schaefer H. Martin , Ebeling Anne 
Published: November 2016

Recent studies have shown that the diversity of flowering plants can enhance pollinator richness and visitation frequency and thereby increase the resilience of pollination. It is assumed that flower traits explain these effects, but it is still unclear which flower traits are responsible, and knowing that, if pollinator richness and visitation frequency are more driven by mass‐ratio effects (mean trait values) or by trait diversity.Here, we analyse a three‐year data set of pollinator observations collected in a European grassland plant diversity experiment (The Jena experiment). The data entail comprehensive flower trait measurements, including reward traits (nectar and pollen amount), morphological traits (height, symmetry, area, colour spectra) and chemical traits (nectar‐amino acid and nectar‐sugar concentration). We test if pollinator species richness and visitation frequency of flower communities depend on overall functional diversity combining all flower traits within a community, single trait diversities (within trait variation) and community‐weighted means of the single traits, using Bayesian inference.Overall functional diversity did not affect pollinator species richness, but reduced visitation frequency. When looking at individual flower traits separately, we found that single trait diversity of flower reflectance and flower morphology were important predictors of pollinator visitation frequency. Moreover, independent of total flower abundance, community‐weighted means of flower height, area, reflectance, nectar‐sugar concentration and nectar‐amino acid concentration strongly affected both pollinator species richness and visitation frequency.Our results, challenge the idea that functional diversity always positively affects ecosystem functions. Nonetheless, we demonstrate that both single trait diversity and mass‐ratio effects of flower traits play an important role for diverse and frequent flower visits, which underlines the functionality of flower traits for pollination services.
Spread of exotic grass in grazed native grass pastures and responses of insect communities
Authors: Monroe Adrian P. , Hill JoVonn G. , Martin James A. 
Published: November 2016

AbstractExotic grasses are widely established across the Southeastern United States for livestock forage, resulting in the structural and compositional simplification of grasslands. Replacing exotic forages with native warm‐season grasses (NWSG) could benefit insects due to increased complexity of plant structure and composition, but livestock grazing also may facilitate spread of remnant exotic grasses such as bermudagrass (Cynodon dactylon) by reducing height and coverage of NWSG. We investigated these relationships among 12 operational‐scale pastures (6.4–10.5 ha) in Mississippi, U.S.A., during May–July (2011–2012). We quantified changes in bermudagrass coverage from one treatment of grazed exotic forages and three treatments of recently established NWSG, including a grazed mixed NWSG polyculture, a grazed Indian grass (Sorghastrum nutans) monoculture to evaluate the effects of stand‐type richness among NWSG pastures, and a non‐grazed NWSG polyculture to evaluate the effects of grazing. We also assessed responses of two insect orders, Orthoptera and Hemiptera, to treatment and bermudagrass coverage. We estimated a 101–190% average increase in coverage of bermudagrass in grazed native grass pastures (NWSG polyculture and Indian grass monoculture), but not in non‐grazed NWSG, suggesting that grazing facilitated the spread of this grass. Composition of Orthopteran and Hemipteran communities was correlated with bermudagrass coverage, and inter‐year differences in composition for both communities in grazed mixed NWSG, and for Hemiptera in grazed Indian grass, corresponded with increasing bermudagrass coverage in those treatments. Our results suggest that incomplete eradication of exotic forages prior to establishment of NWSG may be exacerbated by grazing, which could then impact stand condition and insect communities.
Authoritarianism as a Research Constraint: Political Scientists in China*
Authors: Reny Marie‐Eve 
Published: November 2016

ObjectiveThis article examines the ways the authoritarian nature of the regime in the People's Republic of China constrains the conduct of political science research. It further seeks to identify ways in which researchers have circumvented authoritarian controls.MethodsThe article examines existing scholarly literature and curricula pertaining to Chinese politics to identify methodological and technical tendencies in the research field. It then conducts a deeper, theoretical investigation to show how researchers exploit loopholes and blindspots in the authoritarian system to generate novel research.ResultsThe study finds a marked propensity in the study of Chinese politics toward qualitative research. Research on local politics is considered less sensitive and thus is more prevalent than studies of the central government. Government restrictions have forced scholars to imperfect data for empirical support.ConclusionAlthough it is easier to generate new findings in politically open settings, the authoritarian nature of the Chinese regime does not necessarily hinder advancement in social science. Quantitative research that relies on government‐issued data is useful, but remains liable to government restriction. Qualitative and ethnographic research gives the researcher opportunities to bypass restrictions imposed by the regime. These opportunities depend upon the researcher's ability to immerse herself in the relevant communities, find reliable and context‐aware collaborators, and develop creative ways of collecting information about state behavior.
Regimes and Randomization: Authoritarianism and Field Research in Contemporary Kenya*
Authors: Sheely Ryan 
Published: November 2016

ObjectivesLittle is known about how the legacy of authoritarian politics shapes research in countries that have recently transitioned to democracy. How do previous periods of authoritarian rule shape field research that takes place after a regime transition? To what extent are authoritarian tendencies present in the practice of quantitative field research in a democracy?MethodsI engage in a reflexive and historical analysis of a number of episodes of field research in Kenya. I describe and categorize the two authoritarian political regimes that have governed Kenya: the colonial regime that governed the country from the early 20th century to independence in 1963 and the bureaucratic executive authoritarian regime that governed the country from 1963 until the 2002 election. I then analyze how the historical legacy of each of these regimes shapes the practice of research in contemporary Kenya, using both my own experiences and historical examples.ResultsMy results indicate that although the liberalization of the Kenyan regime over the past 20 years has permitted the expansion of social science research in the country, authoritarian institutions and practices continue to shape field research in the country in two ways. First, the institutional legacies of Kenya's previous authoritarian regimes continue to shape field research by informally shaping the behavior of both public officials and ordinary citizens. Second, the practice of randomized field research can lead to the reinforcement of authoritarian cultural practices and social norms by emphasizing centralization, control, and compliance rather than democratic norms of deliberation, participation, and collective ownership.ConclusionsBoth types of authoritarian influences on field research pose both methodological and ethical problems for field researchers in Kenya and other countries that have recently experienced regime change. I summarize the methodological and normative implications of these findings and provide a set of recommendations for field researchers.
Archivists and Adventurers: Research Strategies for Authoritarian Regimes of the Past and Present*
Authors: Art David 
Published: November 2016

ObjectiveTo analyze the theoretical and political stakes involved in researching authoritarian regimes.MethodA meta‐analysis of recent books and articles on authoritarianism, including the articles in this special volume.ResultsThe prevailing research methods set unrealistic standards for analyses of authoritarianism, with serious consequences for theory building and American foreign policy.ConclusionThe old rules of fieldwork still apply, and scholars are well advised to develop tactics and “work‐arounds” to meet the inherent challenge of discovering useful knowledge about authoritarian regimes. Historical cases of authoritarianism also provide an underused resource for theory development and testing.
On the Outside Looking In: Secrecy and the Study of Authoritarian Regimes*
Authors: Barros Robert 
Published: November 2016

ObjectiveThis study seeks to show how authoritarian secrecy complicates the reliable identification of the inner power configuration in dictatorships. This topic is relevant to recent research on autocratic regime subtypes and institutions.MethodsThe study pursues a theoretical and conceptual analysis of the implications of heteronomous structures of authoritarian power for: the opportunity and motive of autocrats to employ secrecy; the reliability of indirect types of evidence, such as the observable presence of institutions, legislation, or the regime's self‐presentation through media, speeches, and interviews; and the production and preservation of direct sources.ResultsI find that autocratic secrecy presents considerable obstacles for studying the highest levels of authoritarian power; that indirect forms of evidence are equivocal sources; and that, ultimately, we need to know how dictatorships actually operate to reliably classify regimes.ConclusionsSecrecy creates methodological problems for the study of autocracies that are largely absent in the study of democracies.
Standing in the Shadows of Obesity: The Local Food Environment and Obesity in Detroit
Authors: Ledoux Timothy F. , Vojnovic Igor , Manning Thomas June , Pothukuchi Kameshwari 
Published: November 2016

AbstractMuch of the literature examining associations between local food environments and obesity fail to consider whether or not respondents actually utilise the food stores around them. Drawing on survey data, this study examines the relationships between the neighbourhood food environment, mobility and obesity among residents from the lower eastside neighbourhoods of Detroit, Michigan. Certain dimensions of the local food environment are found to contribute to obesity, but these dimensions occur at different scales. Residents who rely on their immediate neighbourhood food environment have a higher likelihood of being obese than residents who do not utilise the stores around them. At a broader level, lower eastside Detroit residents with a greater concentration of fast food establishments around them have a higher possibility of being obese than residents with fewer fast food restaurants around them. The salience of the fast food environment warrants additional attention in terms of public health interventions.
Characterization of a novel form of progressive retinal atrophy in Whippet dogs: a clinical, electroretinographic, and breeding study
Authors: Somma André Tavares , Moreno Juan Carlos Duque , Sato Mario Teruo , Rodrigues Blanche Dreher , Bacellar‐Galdino Marianna , Occelli Laurence Mireille , Petersen‐Jones Simon Michael , Montiani‐Ferreira Fabiano 
Published: November 2016

AbstractObjectiveTo describe a form of progressive retinal atrophy (PRA) in Whippets including clinical, electroretinographic, optical coherence tomographic changes and pedigree analysis.Animals studiedClient‐owned Whippet dogs (n = 51) living in Brazil.ProceduresAll animals were submitted for routine ophthalmic screening for presumed inherited ocular disease, which included the following: visual tests, such as obstacle course tests, in scotopic and photopic conditions, cotton ball test, dazzle reflex, ocular fundus evaluation by indirect ophthalmoscopy followed by fundus photography. Additionally, electroretinography (ERG) and optical coherence tomography (OCT) were performed in 24 and four dogs, respectively.ResultsSixteen dogs were diagnosed with PRA. Vision deficits in dim light were detected in dogs examined at a young age associated with nystagmus. Funduscopic changes included the development of multifocal retinal bullae from 6 months of age. Retinal thinning became apparent later, at which time the bullae were no longer detected. OCT examination of selected young dogs revealed that the retinal bullae were due to separation between photoreceptors and the retinal pigment epithelium, and of dogs with more advanced disease confirmed the development of retinal thinning. Electroretinography in young dogs revealed a negative ERG due to a lack of b‐wave in both scotopic and photopic recordings. With progression, the ERG became unrecordable. Pedigree analysis suggested an autosomal recessive mode of inheritance.ConclusionThe retinal dystrophy reported here in Whippet dogs has a unique phenotype of an initial lack of ERG b‐wave, development of retinal bullae then a progressive generalized retinal degeneration.
Feasibility Study for Vision-Based Cable Force Measurement Using Smartphone
Authors: Zhao Xuefeng , Ri Kwang , Yu Yan , Kang Chunil , Li Mingchu , Ou Jinping 
Published: November 2016

An accurate cable force measurement is one of very important practical problems during construction period as well as during service period of cable stayed bridge. In the recent years, with the advances in smartphone technologies, it is possible to rapidly evaluate structural health status and postevent damage using ubiquitous smartphones.
In this paper, a novel vision-based cable force measurement method using smartphone camera is proposed for the first time, which enable to estimate cable force by recognizing cable vibration using smartphone camera, and then cable model test is carried out to verify the feasibility of the proposed method. The comparison test between the smartphone application Orion-CC measuring cable force from smartphone built-in accelerometer and the proposed method is conducted on a laboratory scale cable model with different sampling rates.
In the proposed method, the vibration responses of cable are obtained by monitoring displacements of a preprinted black circular target attached on the cable model using smartphone camera. The test results showed satisfactory agreements between two methods in both frequency domain and cable force value, demonstrating the feasibility of the proposed cable force measurement method and its advantages such as convenience, ease of operation, and speediness.
Inflatable Octet-Truss Structures
Authors: Robertson M. G. , Haseltine J. , Tawfick S. 
Published: November 2016

The development of variable-stiffness systems is key to the advance of compact engineering solutions in a number of fields. Rigidizable structures exhibit variable-stiffness based on external stimuli. This function is necessary for deployable structures, such as inflatable space antennas, where the deployed structure is semi-permanent. Rigidization is also useful for a wide range of applications, such as prosthetics and exoskeletons, to help support external loads. In general, variable-stiffness designs suffer from a tradeoff between the magnitude of stiffness change and the ability of the structure to resist mechanical failure at any stiffness state.
This paper presents the design, analysis, and fabrication of a rigidizable structure based on inflatable octet-truss cells. An octet-truss is a lattice-like configuration of elements, traditionally beams, arranged in a geometry reminiscent of that of the FCC lattice found in many metals; namely, the truss elements are arranged to form a single interior octahedral cell surrounded by eight tetrahedral cells. The interior octahedral cell is the core of the octet-truss unit cell, and is used as the main structure for examining the mechanics of the unit as a whole. In this work, the elements of the inflatable octet truss are pneumatic air muscles, also called McKibben actuators. Generalized McKibben actuators are a type of tubular pneumatic actuator that possess the ability to either contract or expand axially due to an applied pressure. Their unique kinematics are achieved by using a fiber wrap around an isotropic elastomeric shell. Under normal conditions, pressurizing the isotropic shell causes expansion in all directions, like a balloon. The fiber wrap constrains the ability of the shell to freely expand, due to the fiber stiffness. The wrap geometry thus guides the extensile/contractile motion of the actuator by controlling its kinematics. It is their ability to contract under pressure that makes McKibben actuators unique, and consequently they are of great interest presently to the robotics community due to their similitude to organic muscles. Kinematic analysis from constrained maximization of the shell volume during pressurization is used to obtain relations between the input work due to applied pressure and the resulting shape change due to strain energy. Analytical results are presented to describe the truss stiffness as a function of the McKibben geometry at varying pressures.
Sensorless Method for Switching Energy Harvester Based on Self-Sensing Approach
Authors: Yamamoto Y. , Asahina K. , Yoshimizu K. , Makihara K. 
Published: November 2016

Vibration energy harvesting extracts electrical energy from vibrating structures. The past studies of vibration energy harvesting suggest that the efficiency can be improved by switch regulation in the harvesting circuit. The switch-regulation is carried out depending on the motion of the target structure with the use of vibration sensors such as displacement sensor or accelerometer. This paper proposes a new vibration self-sensing method for switching energy harvesters that do not use those vibration sensors. In this method, the voltage of the piezoelectric transducer is measured, and the structural vibrational status is estimated from the measured voltage. The transducer voltage is not smooth and does not maintain the sinusoidal wave even when the structure vibrates in a sinusoidal wave because the switch energy harvesting method inverses the transducer voltage at every period. Thus, we establish a state observer based on a Kalman filter to estimate three state values of the target harvesting system: modal displacement, modal velocity, and electric charge in the transducer.
This paper describes the construction processes for the observer. The observed value is the transducer voltage. We also show an electric circuit for measuring the transducer voltage. Finally, we confirm the efficiency of the proposed state observer for switch harvesting with numerical simulations.
Design and Experimentation of a Tunably-Compliant Robotic Finger Using Low Melting Point Metals
Authors: Joo Heon , Swensen John P. 
Published: November 2016

In this paper, we describe the fabrication and testing of a tunably-compliant tendon-driven finger implemented through the geometric design of a skeleton made of the low-melting point Field’s metal encased in a silicone rubber. The initial prototype consists of a skeleton comprised of two rods of the metal, with heating elements in thermal contact with the metal at various points along its length, embedded in an elastomer. The inputs to the systems are both the force exerted on the tendon to bend the finger and the heat introduced to liquefy the metal locally or globally along the length of the finger. Selective localized heating allows multiple joints to be created along the length of the finger.
Fabrication was accomplished via a multiple step process of elastomer casting and liquid metal casting. Heating elements such as power resistors or Ni-Cr wire with electric connections were added as an intermediate step before the final elastomer casting. The addition of a tradition tendon actuation was inserted after all casting steps had been completed. While preliminary, this combination of selective heating and engineered geometry of the low-melting point skeletal structure will allow for further investigation into the skeletal geometry and its effects on local and global changes in device stiffness.
Design and Prototyping of a Wearable Assistive Tool for Hand Rehabilitation Using Shape Memory Alloys
Authors: Hadi A. , Alipour K. , Kazeminasab S. , Amerinatanzi A. , Elahinia M. 
Published: November 2016

Disability to move hands perfectly is one of the most severe human physical disabilities, and it is mostly common among adults or those who have experienced serious accidents. It is desired to find a methodology to restore the motion of the hand. To this aim, we proposed and evaluated the use of wearable robots (i.e., a smart glove) for clinical therapy that is equipped with shape memory alloy (SMA) actuators. The developed robotic tool, which is a smart glove, uses the structure of human hand as a base mechanism. This glove compensates the weakness of the hand muscles utilizing the forces produced by SMA actuators. The attractive property of high force to weight ratio in SMAs makes this glove a good candidate to be used as a wearable system.
The glove actuation mechanism is tendon driven. For every finger, two active Degrees Of Freedom (DOFs) are supported in design. Consequently, four tendons are considered for activating each DOF in order to complete opening and closing phases of the fingers. Totally, twenty tendons are used for rehabilitation of a hand through the glove. Using kinematic relations between tendon length and finger movement, the required deflection of each tendon is extracted. Since a short length of SMA wires cannot provide an enough displacement of tendons in the glove, therefore, an extra mechanism was embedded to the developed glove to support the required length of SMA wires. The SMA actuators were selected and mounted on the system to support the tendons of the mechanism effectively. Moreover, the gripping force provided by the developed glove was also studied. To this end, an analysis was accomplished to extract the relationship between tendon actuation and gripping force of the glove.
The obtained results offered a proper model for such a tendon driven glove. Coupling the model of the SMA actuators to that of the tendon driven glove, a composite model of smart glove was extracted. The aforementioned model was simulated numerically. Furthermore, the results were compared with those of the real-world prototype. The obtained results revealed the accuracy of the developed model which will be then employed for both system optimization and model-based control design.