bluuebunny/crossref_metadata_2025 huggingface dataset:
Increasing water‐use efficiency directly through genetic manipulation of stomatal density
Authors: Franks Peter J. , W. Doheny‐Adams Timothy , Britton‐Harper Zoe J. , Gray Julie E.
Published: March 2015

Improvement in crop water‐use efficiency (WUE) is a critical priority for regions facing increased drought or diminished groundwater resources. Despite new tools for the manipulation of stomatal development, the engineering of plants with high WUE remains a challenge.

We used Arabidopsis epidermal patterning factor (EPF) mutants exhibiting altered stomatal density to test whether WUE could be improved directly by manipulation of the genes controlling stomatal density. Specifically, we tested whether constitutive overexpression of EPF2 reduced stomatal density and maximum stomatal conductance (gw(max)) sufficiently to increase WUE.

We found that a reduction in gw(max) via reduced stomatal density in EPF2‐overexpressing plants (EPF2OE) increased both instantaneous and long‐term WUE without altering significantly the photosynthetic capacity. Conversely, plants lacking both EPF1 and EPF2 expression (epf1epf2) exhibited higher stomatal density, higher gw(max) and lower instantaneous WUE, as well as lower (but not significantly so) long‐term WUE.

Targeted genetic modification of stomatal conductance, such as in EPF2OE, is a viable approach for the engineering of higher WUE in crops, particularly in future high‐carbon‐dioxide (CO2) atmospheres.
Translational psychiatry—light at the end of the tunnel
Authors: Jones Kenneth A. , Menniti Frank S. , Sivarao Digavalli V.
Published: March 2015

Neuroscience has made tremendous progress delineating the cellular and molecular processes important for understanding neuronal development and behavior, but this knowledge has been slow to translate to new treatments for psychiatric illness. To accelerate this transfer of knowledge to the human condition requires the wide‐scale adoption of biomarkers that can bridge preclinical and clinical discoveries, and serve as surrogate measures of efficacy before commencing expensive phase III studies. Several biomarker methodologies, including imaging, electroencephalography (EEG), and blood transcriptomics/proteomics, are now showing promise. From an industry perspective, we highlight the utility of quantitative EEG as one example of a translatable biomarker applicable to psychiatric drug development and discuss recent insights into glutamate system dysfunction in schizophrenia and depression gained through translational studies of the drug ketamine.
Comparison of reintroduction and enhancement effects on metapopulation viability
Authors: Halsey Samniqueka J. , Bell Timothy J. , McEachern Kathryn , Pavlovic Noel B.
Published: March 2015

Metapopulation viability depends upon a balance of extinction and colonization of local habitats by a species. Mechanisms that can affect this balance include physical characteristics related to natural processes (e.g. succession) as well as anthropogenic actions. Plant restorations can help to produce favorable metapopulation dynamics and consequently increase viability; however, to date no studies confirm this is true. Population viability analysis (PVA) allows for the use of empirical data to generate theoretical future projections in the form of median time to extinction and probability of extinction. In turn, PVAs can inform and aid the development of conservation, recovery, and management plans. Pitcher's thistle (Cirsium pitcheri) is a dune endemic that exhibited metapopulation dynamics. We projected viability of three natural and two restored populations with demographic data spanning 15–23 years to determine the degree the addition of reintroduced population affects metapopulation viability. The models were validated by comparing observed and projected abundances and adjusting parameters associated with demographic and environmental stochasticity to improve model performance. Our chosen model correctly predicted yearly population abundance for 60% of the population‐years. Using that model, 50‐year projections showed that the addition of reintroductions increases metapopulation viability. The reintroduction that simulated population performance in early‐successional habitats had the maximum benefit. In situ enhancements of existing populations proved to be equally effective. This study shows that restorations can facilitate and improve metapopulation viability of species dependent on metapopulation dynamics for survival with long‐term persistence of C. pitcheri in Indiana likely to depend on continued active management.
Nurses experience of using scientific knowledge in clinical practice: a grounded theory study
Authors: Renolen Åste , Hjälmhult Esther
Published: March 2015

Background

Guidelines recommend the use of evidence‐based practice in nursing. Nurses are expected to give patients care and treatment based on the best knowledge available. They may have knowledge and positive attitudes, but this does not mean that they are basing their work on evidence‐based practice. Knowledge is still lacking about what is needed to successfully implement evidence‐based practice.

Aim

The aim of this study was to gain more knowledge about what nurses perceive as the most important challenge in implementing evidence‐based practice and to explain how they act to face and overcome this challenge.

Method

We used classical grounded theory methodology and collected data through four focus groups and one individual interview in different geographical locations in one large hospital trust in Norway. Fourteen registered clinical practice nurses participated. We analysed the data in accordance with grounded theory, using the constant comparative method.

Results

Contextual balancing of knowledge emerged as the core category and explains how the nurses dealt with their main concern, how to determine what types of knowledge they could trust. The nurses' main strategies were an inquiring approach, examining knowledge and maintaining control while taking care of patients. They combined their own experienced‐based knowledge and the guidelines of evidence‐based practice with a sense of control in the actual situation.

Conclusion

The grounded theory contextual balancing of knowledge may help us to understand how nurses detect what types of knowledge they can trust in clinical practice. The nurses needed to rely on what they did, and they seemed to rely on their own experience rather than on research.
Factors related to self‐efficacy among men and women undergoing outpatient chemotherapy in Japan
Authors: Sato Miho , Sumi Naomi
Published: March 2015

Objective

This study aims to examine factors that influence self‐efficacy in Japanese patients with cancer receiving outpatient chemotherapy and to identify whether there are gender‐specific similarities or differences that determine self‐efficacy in this setting.

Methods

A cross‐sectional survey was conducted among 156 patients with cancer (86 men and 70 women) undergoing chemotherapy as outpatients across five hospitals in Japan. The patients completed the European Organization for Research and Cancer Core Quality of Life questionnaire (EORTC QLQ‐C30), the Self‐Efficacy for Advanced Cancer questionnaire (SEAC) which consists of three subscales (affect regulation efficacy, symptom‐coping efficacy and activities of daily living efficacy), and a patient information form. Multiple regression analysis was conducted to identify factors associated with self‐efficacy in men and women.

Results

In both men and women, insomnia was related to affect regulation efficacy, while fatigue and nausea/vomiting correlated with activities of daily living efficacy. For male patients, fatigue and nausea/vomiting also correlated with affect regulation efficacy and symptom‐coping efficacy. Emotional functioning influenced self‐efficacy for both genders, while physical functioning affected self‐efficacy in female patients only.

Conclusions

These results suggest that to enhance self‐efficacy in Japanese patients with cancer undergoing outpatient chemotherapy, effective intervention is required with regard to the management of both emotional and physical functioning, specifically symptoms such as fatigue, nausea/vomiting and insomnia in both genders. Furthermore, women with a reduced level of physical function may require particular attention, as they may be at risk of lower levels of self‐efficacy.
Use of the Hospital Anxiety and Depression Scale in Spanish caregivers
Authors: Sánchez‐López María Pilar , Limiñana‐Gras Rosa María , Colodro‐Conde Lucía , Cuéllar‐Flores Isabel
Published: March 2015

Background

The Hospital Anxiety and Depression Scale (HADS) is widely used in the assessment of anxiety and depression, but there are scarce data about its psychometric properties in caregivers of older relatives.

Objective

The goal of this study was to analyse the factor structure of the HADS to verify its suitability to assess emotional symptomatology in family caregivers of old people, its internal consistency and confirming its relation with the General Health Questionnaire (GHQ‐12) and an index of disease and physical complaints.

Methods

One hundred and seventy‐five family caregivers (25 men and 150 women) aged 32–86, who were taking care of at least one older person in a situation of dependence, were recruited for this study. A descriptive, comparative, correlational design was employed. The scientific adequacy of the questionnaire and its structure were analysed using confirmatory factor analysis. The scores obtained in the GHQ and in an index of disease and physical complaints were used as external criteria to assess the adequacy of the HADS for caregivers.

Results

Higher levels of anxiety and depression than in the normal population were obtained. The reliability/internal validity of the questionnaire was adequate. A bifactor model, with one subscale for anxiety and one for depression, provides the best fit to the data. The subscales were related to GHQ‐12 and index of diseases/physical complaints.

Conclusions

The HADS was shown to be useful to assess the presence of anxiety and depression in family caregivers, and the original two‐dimensional model is the most adequate.
End of life of patients treated with haemodialysis as narrated by their close relatives
Authors: Axelsson Lena , Klang Birgitta , Lundh Hagelin Carina , Jacobson Stefan H. , Andreassen Gleissman Sissel
Published: March 2015

Aim

The study aimed to describe end of life for patients treated with maintenance haemodialysis as narrated by their close relatives.

Introduction

Many patients undergoing haemodialysis are older, have several comorbidities and underestimated symptoms and are in their last year of life. To improve care, we need to know more about their end‐of‐life situation.

Design

Qualitative and descriptive.

Methods

Qualitative retrospective interviews were conducted with 14 close relatives of deceased haemodialysis patients (3–13 months after death). Data were analysed using qualitative content analysis. The study is ethically approved.

Findings

In the last months, a gradual deterioration in health with acute episodes necessitating hospital admissions was described. This involved diminishing living space and expressions of dejection, but also of joy. Three patterns emerged in the last weeks: uncertain anticipation of death as life fades away; awaiting death after haemodialysis withdrawal; and sudden but not unexpected death following intensive care. Findings show complexities of decisions on haemodialysis withdrawal.

Conclusions

Different end‐of‐life patterns all involved increasingly complex care needs and existential issues. Findings show a need for earlier care planning. The identification of organisational factors to facilitate continuity and whole person care to meet these patients' specific care needs with their complex symptom burdens and comorbidities is needed. Findings indicate the need for integration of a palliative care approach in the treatment of patients in haemodialysis care.
The Use of Calcimimetics for the Treatment of Secondary Hyperparathyroidism: A 10 Year Evidence Review
Authors: Rodríguez Mariano , Goodman William G. , Liakopoulos Vassilios , Messa Piergiorgio , Wiecek Andrzej , Cunningham John
Published: March 2015

Until the discovery of calcimimetics, the management of secondary hyperparathyroidism (SHPT) relied exclusively on treatment with phosphate binders, vitamin D derivatives or surgical parathyroidectomy with limited success. The therapeutic use of calcimimetic agents, together with a better understanding of the pivotal role of the calcium‐sensing receptor (CaSR) in the physiological regulation of parathyroid gland function, substantially advanced the management of hyperparathyroidism in dialysis practice. Calcimimetics bind selectively to the CaSR receptor in parathyroid tissue and enhance the inhibitory effect of extracellular calcium ions on parathyroid hormone (PTH) secretion, thereby reducing PTH levels even when serum calcium concentrations are normal or low. The availability of calcimimetic agents for clinical use has opened a new era in the management of patients with SHPT. Indeed, calcimimetic compounds have been shown to reduce PTH levels and to lower serum calcium concentrations in all forms of hyperparathyroidism, including primary hyperparathyroidism (PHPT) and parathyroid carcinoma. Such findings underscore the critical importance of the CaSR as a therapeutic target in this family of clinical disorders. New calcimimetic agents are being developed that have the potential to offer improved efficacy and safety compared with currently available calcimimetic compounds.
Back‐flow ripples in troughs downstream of unit bars: Formation, preservation and value for interpreting flow conditions
Authors: Herbert Christopher M. , Alexander Jan , Martínez de Álvaro María J.
Published: March 2015

Back‐flow ripples are bedforms created within the lee‐side eddy of a larger bedform with migration directions opposed or oblique to that of the host bedform. In the flume experiments described in this article, back‐flow ripples formed in the trough downstream of a unit bar and changed with mean flow velocity; varying from small incipient back‐flow ripples at low velocities, to well‐formed back‐flow ripples with greater velocity, to rapidly migrating transient back‐flow ripples formed at the greatest velocities tested. In these experiments back‐flow ripples formed at much lower mean back‐flow velocities than predicted from previously published descriptions. This lower threshold mean back‐flow velocity is attributed to the pattern of velocity variation within the lee‐side eddy of the host bedform. The back‐flow velocity variations are attributed to vortex shedding from the separation zone, wake flapping and increases in the size of, and turbulent intensity within, the flow separation eddy controlled by the passage of superimposed bedforms approaching the crest of the bar. Short duration high velocity packets, whatever their cause, may form back‐flow ripples if they exceed the minimum bed shear stress for ripple generation for long enough or, if much faster, may wash them out. Variation in back‐flow ripple cross‐lamination has been observed in the rock record and, by comparison with flume observations, the preserved back‐flow ripple morphology may be useful for interpreting formative flow and sediment transport dynamics.
The role of intracontinental deformation in supercontinent assembly: insights from the Ribeira Belt, Southeastern Brazil (Neoproterozoic West Gondwana)
Authors: Meira Vinícius T. , García‐Casco Antonio , Juliani Caetano , Almeida Renato P. , Schorscher Johann Hans D.
Published: March 2015

In this study, we challenge the multiple collision model for the tectonic evolution of the Neoproterozoic Ribeira Belt in Southeastern Brazil. New U–Pb SHRIMP data reveal Palaeoproterozoic (2153 ± 15 Ma) and Cryogenian (783 ± 6 and 768 ± 8 Ma) granitic rocks in the Embu Domain, and detrital zircon data of metasedimentary units from the Embu and Costeiro domains suggest a coherent tectonic evolution for the whole Ribeira Belt. Rather than by multiple collisions, these data are best explained by a simpler tectonic model involving continent (craton)‐volcanic arc collisions in the Dom Feliciano and Brasilia belts that led to intracontinental crustal thickening of the adjacent thinned hinterland (Ribeira Belt) at ~640–610 Ma, followed by widespread post‐collisional magmatism and rift‐related sedimentation at ~600–540 Ma. We suggest that intracontinental orogeny is a relevant process during supercontinent assembly, as illustrated here by the evolution of significant parts of the Brasiliano orogen.
Thirty Years After Marr's Vision: Levels of Analysis in Cognitive Science
Authors: Peebles David , Cooper Richard P.
Published: March 2015

Thirty years after the publication of Marr's seminal book Vision (Marr, 1982) the papers in this topic consider the contemporary status of his influential conception of three distinct levels of analysis for information‐processing systems, and in particular the role of the algorithmic and representational level with its cognitive‐level concepts. This level has (either implicitly or explicitly) been downplayed or eliminated both by reductionist neuroscience approaches from below that seek to account for behavior from the implementation level and by Bayesian approaches from above that seek to account for behavior in purely computational‐level terms.
Lipoxygenase‐derived 9‐hydro(pero)xides of linoleoylethanolamide interact with ABA signaling to arrest root development during Arabidopsis seedling establishment
Authors: Keereetaweep Jantana , Blancaflor Elison B. , Hornung Ellen , Feussner Ivo , Chapman Kent D.
Published: March 2015

Ethanolamide‐conjugated fatty acid derivatives, also known as N‐acylethanolamines (NAEs), occur at low levels (μg per g) in desiccated seeds, and endogenous amounts decline rapidly with seedling growth. Linoleoylethanolamide (NAE18:2) is the most abundant of these NAEs in seeds of almost all plants, including Arabidopsis thaliana. In Arabidopsis, NAE18:2 may be oxidized by lipoxygenase (LOX) or hydrolyzed by fatty acid amide hydrolase (FAAH) during normal seedling establishment, and this contributes to the normal progression of NAE depletion that is coincident with the depletion of abscisic acid (ABA). Here we provide biochemical, genetic and pharmacological evidence that a specific 9‐LOX metabolite of NAE18:2 [9‐hydro(pero)xy linoleoylethanolamide (9‐NAE‐H(P)OD)] has a potent negative influence on seedling root elongation, and acts synergistically with ABA to modulate the transition from embryo to seedling growth. Genetic analyses using mutants in ABA synthesis (aba1 and aba2), perception (pyr1, pyl1, pyl2, pyl4, pyl5 and pyl8) or transcriptional activation (abi3‐1) indicated that arrest of root growth by 9‐NAE‐H(P)OD requires an intact ABA signaling pathway, and probably operates to increase ABA synthesis as part of a positive feedback loop to modulate seedling establishment in response to adverse environmental conditions. These results identify a specific, bioactive ethanolamide oxylipin metabolite of NAE18:2, different from those of ethanolamide‐conjugated linolenic acid (NAE18:3), as well as a molecular explanation for its inhibitory action, emphasizing the oxidative metabolism of NAEs as an important feature of seedling development.
A Conserved Di‐Basic Motif of Drosophila Crumbs Contributes to Efficient ER Export
Authors: Kumichel Alexandra , Kapp Katja , Knust Elisabeth
Published: March 2015

The Drosophila type I transmembrane protein Crumbs is an apical determinant required for the maintenance of apico‐basal epithelial cell polarity. The level of Crumbs at the plasma membrane is crucial, but how it is regulated is poorly understood. In a genetic screen for regulators of Crumbs protein trafficking we identified Sar1, the core component of the coat protein complex II transport vesicles. sar1 mutant embryos show a reduced plasma membrane localization of Crumbs, a defect similar to that observed in haunted and ghost mutant embryos, which lack Sec23 and Sec24CD, respectively. By pulse‐chase assays in Drosophila Schneider cells and analysis of protein transport kinetics based on Endoglycosidase H resistance we identified an RNKR motif in Crumbs, which contributes to efficient ER export. The motif identified fits the highly conserved di‐basic RxKR motif and mediates interaction with Sar1. The RNKR motif is also required for plasma membrane delivery of transgene‐encoded Crumbs in epithelial cells of Drosophila embryos. Our data are the first to show that a di‐basic motif acts as a signal for ER exit of a type I plasma membrane protein in a metazoan organism.
Riboflavin and UV light treatment of platelets: a protective effect of platelet additive solution?
Authors: van der Meer Pieter F. , Bontekoe Ido J. , Daal Brunette B. , de Korte Dirk
Published: March 2015

BACKGROUND

Pathogen reduction technologies (PRTs) increase the safety of the blood supply, but are also associated with cell damage. Our aim was to investigate the effect of Mirasol PRT on platelet (PLT) concentrates stored in plasma and whether the use of a PLT additive solution (PAS) is able to improve in vitro quality.

STUDY DESIGN AND METHODS

Twenty‐two buffy coats (BCs) were pooled and split into two equal parts. To one half, 2 units of plasma were added, and to the other, 2 units of SSP+ PAS were added. Each part was equally split in half again (to resemble pooling five BCs) and PLT concentrates were prepared. One plasma PLT concentrate was Mirasol treated, and the other served as control; similarly, one SSP+ PLT concentrate was Mirasol treated, and the other not. PLT concentrates were stored for 8 days (n = 12).

RESULTS

Mirasol PRT led to elevated lactate production in PLT concentrates in plasma, giving lower pH values throughout storage. The use of SSP+ mostly abrogated this effect, and Mirasol‐treated PLT concentrates in SSP+ had only slightly higher lactate production rates and annexin A5 binding as control PLT concentrates in plasma. However, irrespective whether plasma or SSP+ was used, Mirasol PRT led to higher CD62P expression and lower hypotonic shock response (HSR) scores.

CONCLUSION

Mirasol treatment leads to higher PLT activation and lower HSR scores both when stored in plasma or SSP+. However, if Mirasol‐treated PLTs are stored in SSP+, lactate metabolism and annexin A5 binding are lower, showing that PAS can partly mitigate the effect of PRT. The clinical relevance of this finding needs to be demonstrated.
A multicenter study on the performance of a fully automated, walk‐away high‐throughput analyzer for pretransfusion testing in the US population
Authors: Roback John D. , Barclay Sheilagh , Moulds JoAnn M. , Denomme Gregory A.
Published: March 2015

BACKGROUND

Moving to automation is a major focus of transfusion centers. Erytra (Grifols) is a walk‐away analyzer with high‐performance and ‐throughput capacity for pretransfusion testing. Efficiency and performance of Erytra with its cards and reagents were evaluated in comparison to Food and Drug Administration (FDA)‐approved reference methods.

STUDY DESIGN AND METHODS

A total of 5279 blood samples (46% patients; 54% donors) were obtained from US blood establishment facilities. Samples were analyzed with Erytra and results were compared with the routine FDA‐licensed automated platforms used by the clinical study sites. A total of 25,217 tests were performed (15,322 ABO/D/reverse typing; 4916 Rh phenotypes, 669 K typing, 838 antibody screens, 759 antibody identifications, 250 cross‐matches, 244 ABO compatibilities by immediate‐spin cross‐match, and 219 direct antiglobulin tests [DATs]).

RESULTS

Global agreement between Erytra and the comparison platforms was 99.66%, with 99.82% positive percent agreement (95% lower confidence bound [LCB], 99.75%) and 99.50% negative percent agreement (95% LCB, 99.37%). There were 85 discrepancies (0.34%), including cross‐matches (n = 13), antibody screens (n = 10), antibody identifications (n = 21), and DATs (n = 5), whereas an excellent concordance was obtained in blood grouping determinations (ABO/D/C/E/c/e/K, 0.04%‐0.22% discrepancies). Analysis of the discrepancies showed that Erytra provided the correct result in 51 of them (60%), with only five false negatives (one O patient transplanted with A, one mixed‐field reaction in a very weak D, one anti‐Vel, two A2rr). Erytra results were 100% reproducible in a series of 3760 repetition tests.

CONCLUSION

Grifols' Erytra analyzer showed reliable efficacy compared with equivalent FDA‐licensed reagents and FDA‐cleared instruments.
Global Competition for Attracting Talents and the World Economy
Authors: Docquier Frédéric , Machado Joël
Published: March 2015

This paper studies the effect of liberalising the international mobility of college‐educated workers on the world economy. First, we combine data on effective and desired migration to identify the net pool of foreign talents (NPFT) of selected high‐income countries. So far, the EU‐15 has poorly benefited from its NPFT while the US has mobilised a large portion of it. Second, we use a micro‐founded model to simulate the effects of skill‐selective liberalisation shocks. In our benchmark model, a worldwide liberalisation induces larger long‐run income gains for the EU‐15 (+8.8 per cent) than for the US (+5.9 per cent). However, less attractive EU countries such as Austria, Belgium, Germany, Greece, Luxembourg and the Netherlands benefit less than the US. In addition, liberalising high‐skilled migration decreases income per worker by 2.5 per cent in developing countries. Overall, it increases efficiency (+6.2 per cent in the worldwide average level of income per capita) and inequality (+1.2 percentage points in the Theil inequality index). Much greater effects can be obtained if total factor productivity varies with human capital.
Design and Performance Evaluation of a Bio-Inspired and Single-Motor-Driven Hexapod Robot With Dynamical Gaits
Authors: Huang Ke-Jung , Chen Shen-Chiang , Komsuoglu Haldun , Lopes Gabriel , Clark Jonathan , Lin Pei-Chun
Published: March 2015

Over its lifetime, the hexapedal robot RHex has shown impressive performance. Combining preflexes with a range of control schemes, various behaviors such as leaping, running, bounding, as well as running on rough terrain have been exhibited. In order to better determine the extent to which the passive and mechanical aspects of the design contribute to performance, a new version of the hexapedal spring-loaded inverted pendulum (SLIP)-based runner with a novel minimal control scheme is developed and tested. A unique drive mechanism is utilized to allow for operation (including steering) of the robot with only two motors. The simplified robot operates robustly and it exhibits walking, SLIP-like running, or high-speed motion profiles depending only on the actuation frequency. In order to better capture the critical nonlinear properties of the robot’s legs, a more detailed dynamic model termed R2-SLIP is presented. The performance of the robot is compared to the basic SLIP, the R-SLIP, and this new R2-SLIP model. Furthermore, these results suggest that, in the future, the R2-SLIP model can be used to tune/improve the design of the leg compliance and noncircular gears to optimize performance.
Velocity-Regulated Path Planning Algorithm for Aerosol Printing Systems
Authors: Thompson Bradley , Yoon Hwan-Sik
Published: March 2015

Aerosol printing is one of the common methods used in printed electronics. In this study, an improved path planning algorithm is developed for an aerosol printing system. The continuous aerosol stream provided by a printing nozzle requires a constant relative velocity between the printer head and substrate in order to evenly deposit materials. To ensure consistency, the proposed algorithm confines speed fluctuations by predetermining potential velocity errors and compensating with a novel scheme. The path planning algorithm can control motion of an XY stage for an arbitrary printing path and desired velocity while minimizing material waste. Linear segments with parabolic blends (LSPB) trajectory planning is used during printing, and minimum time trajectory (MTT) planning is used during printer transition. Simulation results demonstrate the algorithm's improved capability to maintain the desired velocity while minimizing print time.
Rigidity Analysis of Protein Molecules
Authors: Shahbazi Zahra , Demirtas Ahmet
Published: March 2015

Intrinsic flexibility of protein molecules enables them to change their 3D structure and perform their specific task. Therefore, identifying rigid regions and consequently flexible regions of proteins has a significant role in studying protein molecules' function. In this study, we developed a kinematic model of protein molecules considering all covalent and hydrogen bonds in protein structure. Then, we used this model and developed two independent rigidity analysis methods to calculate degrees of freedom (DOF) and identify flexible and rigid regions of the proteins. The first method searches for closed loops inside the protein structure and uses Grübler–Kutzbach (GK) criterion. The second method is based on a modified 3D pebble game. Both methods are implemented in a matlab program and the step by step algorithms for both are discussed. We applied both methods on simple 3D structures to verify the methods. Also, we applied them on several protein molecules. The results show that both methods are calculating the same DOF and rigid and flexible regions. The main difference between two methods is the run time. It's shown that the first method (GK approach) is slower than the second method. The second method takes 0.29 s per amino acid versus 0.83 s for the first method to perform this rigidity analysis.
Rotational Stiffness of American Football Shoes Affects Ankle Biomechanics and Injury Severity
Authors: Button Keith D. , Braman Jerrod E. , Davison Mark A. , Wei Feng , Schaeffer Maureen C. , Haut Roger C.
Published: March 2015

While previous studies have investigated the effect of shoe–surface interaction on injury risk, few studies have examined the effect of rotational stiffness of the shoe. The hypothesis of the current study was that ankles externally rotated to failure in shoes with low rotational stiffness would allow more talus eversion than those in shoes with a higher rotational stiffness, resulting in less severe injury. Twelve (six pairs) cadaver lower extremities were externally rotated to gross failure while positioned in 20 deg of pre-eversion and 20 deg of predorsiflexion by fixing the distal end of the foot, axially loading the proximal tibia, and internally rotating the tibia. One ankle in each pair was constrained by an American football shoe with a stiff upper, while the other was constrained by an American football shoe with a flexible upper. Experimental bone motions were input into specimen-specific computational models to examine levels of ligament elongation to help understand mechanisms of ankle joint failure. Ankles in flexible shoes allowed 6.7±2.4 deg of talus eversion during rotation, significantly greater than the 1.7±1.0 deg for ankles in stiff shoes (p = 0.01). The significantly greater eversion in flexible shoes was potentially due to a more natural response of the ankle during rotation, possibly affecting the injuries that were produced. All ankles failed by either medial ankle injury or syndesmotic injury, or a combination of both. Complex (more than one ligament or bone) injuries were noted in 4 of 6 ankles in stiff shoes and 1 of 6 ankles in flexible shoes. Ligament elongations from the computational model validated the experimental injury data. The current study suggested flexibility (or rotational stiffness) of the shoe may play an important role in both the severity of ankle injuries for athletes.
The Use of Shear Thickening Nanocomposites in Impact Resistant Materials
Authors: Fowler Jeremy N. , Pallanta Anthony A. , Swanik Charles B. , Wagner Norman J.
Published: March 2015

The work presented here demonstrates using a novel, field-responsive nanocomposite based on shear thickening fluids (STFs) as responsive protective materials with superior damping and energy adsorption properties. Peak forces and accelerations measured using an instrumented Instron™ drop tower demonstrate that STF nanocomposite prototypes and impact foam taken from a commercial football helmet have similar performance for low kinetic energy impacts. However, tests with STF nanocomposite samples exhibit significantly reduced peak acceleration and peak force for impacts above 15 J. Thus, the STF containing nanocomposite material provides improved energy adsorption upon impact as compared to the commercial foam. These tests suggest that STF nanocomposite materials have promising potential as novel energy dissipating components in personal protective equipment.
Wave Based Method for Free and Forced Vibration Analysis of Cylindrical Shells With Discontinuity in Thickness
Authors: Chen Meixia , Xie Kun , Xu Kun , Yu Peng
Published: March 2015

Wave based method (WBM) is presented to analyze the free and forced vibration of cylindrical shells with discontinuity in thickness. The hull is first divided into multiple segments according to the locations of thickness discontinuity and/or driving points, and then the Flügge theory is adopted to describe the motion of cylindrical segments. The dynamic field variables in each segment are expressed as wave function expansions, which accurately satisfy the equations of motion and can be used to analyze arbitrary boundary conditions, e.g., classical or elastic boundary conditions. Finally, the boundary conditions and interface continuity conditions between adjacent segments are used to assemble the final governing equation to obtain the free and forced vibration results. By comparing with the results existing in open literate and calculated by finite element method (FEM), the present method WBM is verified. Furthermore, the influences of the boundary conditions and the locations of thickness discontinuity on the beam mode frequency and fundamental frequency are discussed. The effects of the direction of external force, location of external point force, and the structural damping on the forced vibration are also analyzed.
Numerical Investigation on Frequency Jump of Flow Over a Cavity Using Large Eddy Simulation
Authors: Wang Yuchuan , Tan Lei , Wang Binbin , Cao Shuliang , Zhu Baoshan
Published: March 2015

Large eddy simulation (LES) approach was used to investigate jumps of primary frequency of shear layer flow over a cavity. Comparisons between computational results and experimental data show that LES is an appropriate approach to accurately capturing the critical values of velocity and cavity length of a frequency jump, as well as characteristics of the separated shear layer. The drive force of the self-sustained oscillation of impinging shear layer is fluid injection and reinjection. Flow patterns in the shear layer and cavity before and after the frequency jump demonstrate that the frequency jump is associated with vortex–corner interaction. Before frequency jump, a mature vortex structure is observed in shear layer. The vortex is clipped by impinging corner at approximately half of its size, which induces strong vortex–corner interaction. After frequency jump, successive vortices almost escape from impinging corner without the generation of a mature vortex, thereby indicating weaker vortex–corner interaction. Two wave peaks are observed in the shear layer after the frequency jump because of: (1) vortex–corner interaction and (2) centrifugal instability in cavity. Pressure fluctuations inside the cavity are well regulated with respect to time. Peak values of correlation coefficients close to zero time lags indicate the existence of standing waves inside the cavity. Transitions from a linear to a nonlinear process occurs at the same position (i.e., x/H = 0.7) for both velocity and cavity length variations. Slopes of linear region are solely the function of cavity length, thereby showing increased steepness with increased cavity length.
Thermo-Fluid-Stress-Deformation Analysis of Two-Layer Microchannels for Cooling Chips With Hot Spots
Authors: Abdoli Abas , Dulikravich George S. , Vasquez Genesis , Rastkar Siavash
Published: March 2015

Two-layer single phase flow microchannels were studied for cooling of electronic chips with a hot spot. A chip with 2.45 × 2.45 mm footprint and a hot spot of 0.5 × 0.5 mm in its center was studied in this research. Two different cases were simulated in which heat fluxes of 1500 W cm−2 and 2000 W cm−2 were applied at the hot spot. Heat flux of 1000 W cm−2 was applied on the rest of the chip. Each microchannel layer had 20 channels with an aspect ratio of 4:1. Direction of the second microchannel layer was rotated 90 deg with respect to the first layer. Fully three-dimensional (3D) conjugate heat transfer analysis was performed to study the heat removal capacity of the proposed two-layer microchannel cooling design for high heat flux chips. In the next step, a linear stress analysis was performed to investigate the effects of thermal stresses applied to the microchannel cooling design due to variations of temperature field. Results showed that two-layer microchannel configuration was capable of removing heat from high heat flux chips with a hot spot.
Cloud Manufacturing: Current Trends and Future Implementations
Authors: Buckholtz Ben , Ragai Ihab , Wang Lihui
Published: March 2015

Manufacturing technology changes with the needs of consumers. The globalization of the world economy has helped to create the concept of cloud manufacturing (CM). The purpose of this paper is to provide both an overview and an update on the status of CM and define the key technologies that are being developed to make CM a dependable configuration in today's manufacturing industry. Topics covered include: cloud computing (CC), the role of small and medium enterprises (SMEs), pay-as-you-go, resource virtualization, interoperability, security, equipment control, and the future outlook of the development of CM.
Cerebrospinal fluid involvement in acute promyelocytic leukaemia at presentation
Authors: Mishra Jyoti , Gupta Mayank
Published: March 2015

In acute promyelocytic leukaemia (APL), extramedullary disease (EMD) is rare but can occur in those who relapse following therapy. Although the most common site of EMD in APL is central nervous system (CNS) and skin, CNS involvement in recently diagnosed patients with APL is very rare and rarely described. We report cerebrospinal fluid involvement in a case of APL, on day 3 of induction therapy.
Relationships between fungal endophytes and wood-rot fungi in wood of Platanus acerifolia in urban environments
Authors: Robles Carolina A. , Lopez Silvia E. , McCargo Patricia D. , Carmarán Cecilia C.
Published: March 2015

Urban forests, which are highly valuable for the urban environment, include trees from city streets that might be susceptible to wood-decay fungi. Fungal endophytes can colonize healthy plant tissues without causing external disease symptoms in standing trees. In this study, the diversity of endophytes isolated from wood of Platanus acerifolia (Aiton) Willd. from Buenos Aires, Argentina, is described and related to different levels of urban disturbance, tree age, and presence of wood-decay basidiomycetes. Samples were obtained from 28 asymptomatic trees (1643 wood core fragments) and 75 symptomatic trees (1516 wood sample fragments) from four sites with different levels of human disturbance. Fungal isolates were morphologically identified, and potential wood-decay isolates were phylogenetically analyzed. Twenty-seven endophytic taxa, including five basidiomycetes, were identified. The multivariate analysis suggested that the endophyte community of wood is highly influenced by the level of urban disturbance, followed by tree age and presence of potential pathogenic basidiomycetes.
Role of division algebra in seven-dimensional gauge theory
Authors: Kalauni Pushpa , Barata J. C. A.
Published: March 2015

The algebra of octonions 𝕆 forms the largest normed division algebra over the real numbers ℝ, complex numbers ℂ and quaternions ℍ. The usual three-dimensional vector product is given by quaternions, while octonions produce seven-dimensional vector product. Thus, octonionic algebra is closely related to the seven-dimensional algebra, therefore one can extend generalization of rotations in three dimensions to seven dimensions using octonions. An explicit algebraic description of octonions has been given to describe rotational transformation in seven-dimensional space. We have also constructed a gauge theory based on non-associative algebra to discuss Yang–Mills theory and field equation in seven-dimensional space.
The Use of Ensemble-Based Data Preprocessing Techniques for Software Defect Prediction
Authors: Gao Kehan , Khoshgoftaar Taghi M. , Napolitano Amri
Published: March 2015

Software defect prediction models that use software metrics such as code-level measurements and defect data to build classification models are useful tools for identifying potentially-problematic program modules. Effectiveness of detecting such modules is affected by the software measurements used, making data preprocessing an important step during software quality prediction. Generally, there are two problems affecting software measurement data: high dimensionality (where a training dataset has an extremely large number of independent attributes, or features) and class imbalance (where a training dataset has one class with relatively many more members than the other class). In this paper, we present a novel form of ensemble learning based on boosting that incorporates data sampling to alleviate class imbalance and feature (software metric) selection to address high dimensionality. As we adopt two different sampling methods (Random Undersampling (RUS) and Synthetic Minority Oversampling (SMOTE)) in the technique, we have two forms of our new ensemble-based approach: selectRUSBoost and selectSMOTEBoost. To evaluate the effectiveness of these new techniques, we apply them to two groups of datasets from two real-world software systems. In the experiments, four learners and nine feature selection techniques are employed to build our models. We also consider versions of the technique which do not incorporate feature selection, and compare all four techniques (the two different ensemble-based approaches which utilize feature selection and the two versions which use sampling only). The experimental results demonstrate that selectRUSBoost is generally more effective in improving defect prediction performance than selectSMOTEBoost, and that the techniques with feature selection do help for getting better prediction than the techniques without feature selection.
Continuous CMMI Assessment Using Non-Invasive Measurement and Process Mining
Authors: Astromskis Saulius , Janes Andrea , Sillitti Alberto , Succi Giancarlo
Published: March 2015

The reputation of lightweight software development processes such as Agile and Lean is damaged by practitioners that claim benefits of such processes that are not true.

Teams that want to demonstrate their seriousness, could benefit from matching their processes to the CMMI model, a recognized model by industry and the public administration. CMMI stands for Capability Maturity Model Integration and provides a reference model to improve and evaluate processes according to their maturity based on best practices.

On the other hand, particularly in a lightweight software development process, the costs of a CMMI appraisal are hard to justify since its advantages are not directly related to the creation of value for the customer.

This paper presents Jidoka4CMMI, a tool that — once a CMMI appraisal has been conducted — allows the documentation of the assessment criteria in form of executable test cases. The test cases, and so the CMMI appraisal, can be repeated anytime, without additional costs.

The use of Jidoka4CMMI increases the benefits of conducting a CMMI appraisal. We hope that this encourages practitioners using lightweight software development processes to assess their processes using a CMMI model.
A Causal Model for Analyzing the Impact of Graphical Modeling Languages on Usability
Authors: Schalles Christian , Creagh John , Rebstock Michael
Published: March 2015

Today, developing the conceptual design of information systems has become inconceivable without the support of graphical models. Models are developed using graph-based modeling languages such as UML. This study focuses on the impact of metamodel properties on different usability attributes in the domain of graphical modeling languages. The study is based on a model of hypotheses including a structural causal model developed under consideration of cognitive theories and usability theory. Survey data is collected and the causal hypotheses are assessed using a structure equation modeling approach. The study shows important findings for practical and theoretical issues of how differing modeling languages are influencing usability attributes on causal stages in the modeling domain. The main focus of this article is to define differences and similarities of how language metaproperties impact usability attributes in model interpretation scenarios.
A mathematical model for volatility flocking with a regime switching mechanism in a stock market
Authors: Bae Hyeong-Ohk , Ha Seung-Yeal , Kim Yongsik , Lee Sang-Hyeok , Lim Hyuncheul , Yoo Jane
Published: March 2015

We present a mathematical model for stock market volatility flocking. Our proposed model consists of geometric Brownian motions with time-varying volatilities coupled with Cucker–Smale (C–S) flocking and regime switching mechanisms. For all-to-all interactions, we assume that all assets' volatilities are coupled to each other with a constant interaction weight, and we show that the common volatility emerges asymptotically and discuss its financial applications. We also provide several numerical simulations and compare them to existing analytical results.
FINDING THE WAY TO AMBIDEXTERITY: EXPLORING THE RELATIONSHIPS AMONG ORGANISATIONAL DESIGN, KNOWLEDGE CREATION AND INNOVATION
Authors: MARTINI ANTONELLA , NEIROTTI PAOLO , ALOINI DAVIDE
Published: March 2015

Research suggests the firm's structural and contextual attributes that foster ambidexterity, but theory and testing on their combined effects on knowledge creation, ambidexterity and financial performance remain rather poor. By using a theoretical perspectives built on organisation design and the knowledge-based view of the firm, this article takes into consideration firms' exploration attainments and exploitation initiatives in relation to both their ability to create knowledge in innovation processes and their capacity to apply it into product innovation. Using data from a survey on 112 hi-tech firms in Italy, results show that organisational context attributes influence firm's degree of ambidexterity in knowledge creation in the innovation processes, but it does not have a direct influence on the actual degree of ambidexterity in innovation development. A fundamental condition to ambidexterity in innovation development is the structural separation of exploration and exploitation innovation initiatives. Specifically, we found that structural separation of these initiatives within the organisation directly affects ambidexterity and leads to higher sales growth than when firms achieve ambidexterity through an appropriate organisational context solely. These findings provide a rich explanation of the way firms develop ambidexterity and can obtain superior economic performance from it.