bluuebunny/crossref_metadata_2025 huggingface dataset:
Muscle Activation and Performance During Trunk Strength Testing in High-Level Female and Male Football Players
Authors: Roth Ralf , Donath Lars , Zahner Lukas , Faude Oliver
Published: December 2015

For performance and injury prevention in sport, core strength and endurance are focused prerequisites. Therefore we evaluated characteristics of trunk muscle activation and performance during strength-endurance related trunk field tests. Strength-endurance ability, as total time to failure, and activation of trunk muscles was measured in 39 football players of the highest German female football league (Bundesliga) (N = 18, age: 20.7 y [SD 4.4]) and the highest national male under-19 league (N = 21, age: 17.9 y [0.7]) in prone plank, side plank, and dorsal position. Maximal isometric force was assessed during trunk extension and flexion, rotation, and lateral flexion to normalize EMG and to compare with the results of strength-endurance tests. For all positions of endurance strength tests, a continuous increase in normalized EMG activation was observed (P < .001). Muscle activation of the rectus abdominis and external oblique in prone plank position exceeded the maximal voluntary isometric contraction activation, with a significantly higher activation in females (P = .02). We conclude, that in the applied strength-endurance testing, the activation of trunk muscles was high, especially in females. As high trunk muscle activation can infer fatigue, limb strength can limit performance in prone and side plank position, particularly during high trunk muscle activation.
Comparison of Estimated and Measured Muscle Activity During Inclined Walking
Authors: Alexander Nathalie , Schwameder Hermann
Published: December 2015

While inclined walking is a frequent daily activity, muscle forces during this activity have rarely been examined. Musculoskeletal models are commonly used to estimate internal forces in healthy populations, but these require a priori validation. The aim of this study was to compare estimated muscle activity using a musculoskeletal model with measured EMG data during inclined walking. Ten healthy male participants walked at different inclinations of 0°, ± 6°, ± 12°, and ± 18° on a ramp equipped with 2 force plates. Kinematics, kinetics, and muscle activity of the musculus (m.) biceps femoris, m. rectus femoris, m. vastus lateralis, m. tibialis anterior, and m. gastrocnemius lateralis were recorded. Agreement between estimated and measured muscle activity was determined via correlation coefficients, mean absolute errors, and trend analysis. Correlation coefficients between estimated and measured muscle activity for approximately 69% of the conditions were above 0.7. Mean absolute errors were rather high with only approximately 38% being ≤ 30%. Trend analysis revealed similar estimated and measured muscle activities for all muscles and tasks (uphill and downhill walking), except m. tibialis anterior during uphill walking. This model can be used for further analysis in similar groups of participants.
Orthotic Heel Wedges Do Not Alter Hindfoot Kinematics and Achilles Tendon Force During Level and Inclined Walking in Healthy Individuals
Authors: Weinert-Aplin Robert A. , Bull Anthony M.J. , McGregor Alison H.
Published: December 2015

Conservative treatments such as in-shoe orthotic heel wedges to treat musculoskeletal injuries are not new. However, weak evidence supporting their use in the management of Achilles tendonitis suggests the mechanism by which these heel wedges works remains poorly understood. It was the aim of this study to test the underlying hypothesis that heel wedges can reduce Achilles tendon load. A musculoskeletal modeling approach was used to quantify changes in lower limb mechanics when walking due to the introduction of 12-mm orthotic heel wedges. Nineteen healthy volunteers walked on an inclinable walkway while optical motion, force plate, and plantar pressure data were recorded. Walking with heel wedges increased ankle dorsiflexion moments and reduced plantar flexion moments; this resulted in increased peak ankle dorsiflexor muscle forces during early stance and reduced tibialis posterior and toe flexor muscle forces during late stance. Heel wedges did not reduce overall Achilles tendon force during any walking condition, but did redistribute load from the medial to lateral triceps surae during inclined walking. These results add to the body of clinical evidence confirming that heel wedges do not reduce Achilles tendon load and our findings provide an explanation as to why this may be the case.
A Global Gait Asymmetry Index
Authors: Cabral Silvia , Resende Renan A. , Clansey Adam C. , Deluzio Kevin J. , Selbie W. Scott , Veloso António P.
Published: December 2015

High levels of gait asymmetry are associated with many pathologies. Our long-term goal is to improve gait symmetry through real-time biofeedback of a symmetry index. Symmetry is often reported as a single metric or a collective signature of multiple discrete measures. While this is useful for assessment, incorporating multiple feedback metrics presents too much information for most subjects to use as visual feedback for gait retraining. The aim of this article was to develop a global gait asymmetry (GGA) score that could be used as a biofeedback metric for gait retraining and to test the effectiveness of the GGA for classifying artificially-induced asymmetry. Eighteen participants (11 males; age 26.9 y [SD = 7.7]; height 1.8 m [SD = 0.1]; body mass 72.7 kg [SD = 8.9]) walked on a treadmill in 3 symmetry conditions, induced by wearing custom-made sandals: a symmetric condition (identical sandals) and 2 asymmetric conditions (different sandals). The GGA score was calculated, based on several joint angles, and compared between conditions. Significant differences were found among all conditions (P < .001), meaning that the GGA score is sensitive to different levels of asymmetry, and may be useful for rehabilitation and assessment.
Comparison of Two Methods to Compute Respiratory Volumes Using Optoelectronic Plethysmography
Authors: Meric Henri , Lofaso Frédéric , Falaize Line , Pradon Didier
Published: December 2015

Plethysmography is an indispensable component of clinical lung function testing. However, lung volume measurement in the supine position using an optoelectronic system requires the placement of reflective markers on the anterior and lateral torso surface. The conventional method computes breath-by-breath changes in the volume between the markers and the bed, which serves as the reference plane. In contrast, the surface method consists of measuring the volume delineated by the surface area of the marker network at the onset and end of inspiration. We compared these 2 methods to spirometry during spontaneous breathing in 11 healthy volunteers and in 14 patients receiving routine visits for neuromuscular disease. Bland-Altman plots showed that agreement with spirometry was better for the surface method that the conventional method. Our results open up prospects for integrating these methods in the development of new devices.
The Effect of High- and Low-Damping Prosthetic Foot Structures on Knee Loading in the Uninvolved Limb Across Different Walking Speeds
Authors: Jin Li , Adamczyk Peter G. , Roland Michelle , Hahn Michael E.
Published: December 2015

Lower limb amputation has been associated with secondary impairments such as knee osteoarthritis in the uninvolved limb. Greater knee loading in the frontal plane has been related to severity and rate of progression in knee osteoarthritis. Reduced push-off work from the involved limb can increase uninvolved limb knee loading. However, little is known about specific effects that prosthetic foot damping may have on uninvolved limb loading. We hypothesized that uninvolved limb peak knee internal abduction moment (IAM) and loading rates would be greater when using a high-damping foot compared with a low-damping foot, across walking speeds. Eight healthy, young subjects walked in a prosthesis simulator boot using the experimental feet. Greater uninvolved limb first peak IAM (+16% in fast speed, P = .002; +11% in slow speed, P = .001) and loading rates (+11% in fast speed, P = .003) were observed when using the high-damping foot compared with low-damping foot. Within each foot, uninvolved limb first peak IAM and loading rates had a trend to increase with increased walking speed. These findings suggest that damping properties of prosthetic feet are related to uninvolved limb peak knee IAM and loading rates.
Physical Activity and Aging Research: A Bibliometric Analysis
Authors: Müller Andre Matthias , Ansari Payam , Ebrahim Nader Ale , Khoo Selina
Published: December 2015

Physical activity and aging research has burgeoned in the past few decades. However, despite the increase in scholarly publications, no attempts have been made to summarize the publication landscape and identify work that has had great impact on physical activity and aging research. We conducted a bibliometric analysis and collected publication data from 1980 to February 6, 2015, in the Web of Science Core Collection. Of 9,935 publications, most were published after 2007 and almost 60% were in the category of geriatrics and gerontology or sport sciences. Highly cited publications (n = 45) were mostly authored by researchers from US institutions and were quantitative in nature. Publications that reported on the associations between physical activity and health, or effects of physical activity on health, in older adults made up 60% of the highly cited publications. We expect more scholars from various backgrounds and geographical regions to join the conversation on physical activity and aging.
Correlation Between Ankle-Dorsiflexion and Hip-Flexion Range of Motion and the Functional Movement Screen Hurdle-Step Score
Authors: Janicki Jacob J. , Switzler Craig L. , Hayes Bradley T. , Hicks-Little Charlie A.
Published: December 2015

Context:

Functional movement screening (FMS) has been gaining popularity in the fields of sports medicine and performance. Currently, limited research has examined whether FMS screening that identifies low FMS scores is attributed primarily to limits in range of motion (ROM).

Objective:

To compare scores from the FMS hurdle-step movement with ROM measurements for ankle dorsiflexion and hip flexion (HF).

Design:

Correlational research design.

Setting:

Sports medicine research laboratory.

Participants:

20 healthy active male (age 21.2 ± 2.4 y, weight 77.8 ± 10.2 kg, height 180.8 ± 6.8 cm) and 20 healthy active female (21.3 ± 2.0 y, 67.3 ± 8.9 kg, 167.4 ± 6.6 cm) volunteers.

Intervention:

All 40 participants completed 3 trials of the hurdle-step exercise bilaterally and goniometric ROM measurements for active ankle dorsiflexion and HF.

Main Outcome Measures:

Correlations were determined between ROM and FMS scores for right and left legs. In addition, mean data were compared between FMS scores, gender, and dominant and nondominant limbs.

Results:

There were no significant correlations present when all participants were grouped. However, when separated by gender significant correlations were identified. There was a weak correlation with HF and both hurdle-step (HS) and average hurdle-step (AHS) scores on both left (r = .536, P = .015 and r = .512, P = .012) and right (r = .445, P = .049 and r = .565, P = .009) legs for women. For men, there was a poor negative correlation of HF and both HS and AHS on the left leg (r = –.452, P = .045 and r = .451, P = .046).

Conclusion:

Our findings suggest that although hip and ankle ROMs do not have a strong relationship with FMS hurdle-step scores, they are a contributing factor. More research should be conducted to identify other biomechanical factors that contribute to individual FMS test scores.
Effects of Experimental Anterior Knee Pain on Muscle Activation During Landing and Jumping Performed at Various Intensities
Authors: Park Jihong , Denning W. Matt , Pitt Jordan D. , Francom Devin , Hopkins J. Ty , Seeley Matthew K.
Published: December 2015

Context:

Although knee pain is common, some facets of this pain are unclear. The independent effects (ie, independent from other knee injury or pathology) of knee pain on neural activation of lower-extremity muscles during landing and jumping have not been observed.

Objective:

To investigate the independent effects of knee pain on lower-extremity muscle (gastrocnemius, vastus medialis, medial hamstrings, gluteus medius, and gluteus maximus) activation amplitude during landing and jumping, performed at 2 different intensities.

Design:

Laboratory-based, pretest, posttest, repeated-measures design, where all subjects performed both data-collection sessions.

Methods:

Thirteen able-bodied subjects performed 2 different land and jump tasks (forward and lateral) under 2 different conditions (control and pain), at 2 different intensities (high and low). For the pain condition, experimental knee pain was induced via a hypertonic saline injection into the right infrapatellar fat pad. Functional linear models were used to evaluate the influence of experimental knee pain on muscle-activation amplitude throughout the 2 land and jump tasks.

Results:

Experimental knee pain independently altered activation for all of the observed muscles during various parts of the 2 different land and jump tasks. These activation alterations were not consistently influenced by task intensity.

Conclusion:

Experimental knee pain alters activation amplitude of various lower-extremity muscles during landing and jumping. The nature of the alteration varies between muscles, intensities, and phases of the movement (ie, landing and jumping). Generally, experimental knee pain inhibits the gastrocnemius, medial hamstring, and gluteus medius during landing while independently increasing activation of the same muscles during jumping.
Breaking up prolonged sitting time with walking does not affect appetite or gut hormone concentrations but does induce an energy deficit and suppresses postprandial glycaemia in sedentary adults
Authors: Bailey Daniel P. , Broom David R. , Chrismas Bryna C.R. , Taylor Lee , Flynn Edward , Hough John
Published: December 2015

Breaking up periods of prolonged sitting can negate harmful metabolic effects but the influence on appetite and gut hormones is not understood and is investigated in this study. Thirteen sedentary (7 female) participants undertook three 5-h trials in random order: (i) uninterrupted sitting (SIT), (ii) seated with 2-min bouts of light-intensity walking every 20 min (SIT + LA), and (iii) seated with 2-min bouts of moderate-intensity walking every 20 min (SIT + MA). A standardised test drink was provided at the start of each trial and an ad libitum pasta test meal provided at the end of each trial. Subjective appetite ratings and plasma acylated ghrelin, peptide YY, insulin, and glucose were measured at regular intervals. Area under the curve (AUC) was calculated for each variable. AUC values for appetite and gut hormone concentrations were unaffected in the activity breaks conditions compared with uninterrupted sitting (linear mixed modelling: p > 0.05). Glucose AUC was lower in SIT + MA than in SIT + LA (p = 0.004) and SIT (p = 0.055). There was no difference in absolute ad libitum energy intake between conditions (p > 0.05); however, relative energy intake was lower in SIT + LA (39%; p = 0.011) and SIT + MA (120%; p < 0.001) than in SIT. In conclusion, breaking up prolonged sitting does not alter appetite and gut hormone responses to a meal over a 5-h period. Increased energy expenditure from activity breaks could promote an energy deficit that is not compensated for in a subsequent meal.
Responses of Eastern Red-backed Salamander (Plethodon cinereus) abundance 1 year after application of wood ash in a northern hardwood forest
Authors: Gorgolewski Adam , Caspersen John , Hazlett Paul , Jones Trevor , Tran Honghi , Basiliko Nathan
Published: December 2015

Wood ash may be an effective soil amendment in North America to restore acidified and low-nutrient forest soils, but little research exists beyond its effects on soil and plants. Eastern Red-backed Salamander (Plethodon cinereus (Green, 1818)) abundance was assessed in a northern hardwood forest 1 year following an ash-addition field trial. Plots were established with fly ash and bottom ash treatments of 0, 1, 4, and 8 Mg·ha−1 (n = 4), and cover boards were positioned both with and without ash beneath. One year following ash additions, salamander abundance had increased under boards with fly ash beneath, and bottom ash had no effect. Soil pH and electrical conductivity increased under cover boards with ash beneath them and for uncovered soil, and the effects were strongest under cover boards with ash beneath. The effects of ash were generally stronger at higher dosages, and fly ash was stronger than bottom ash. The moisture holding capacity of fly ash was 60% higher than the soil and was 63% lower than the soil for bottom ash, but they had little effect on moisture of the forest floor. These results suggest that ash altered salamander abundance via soil pH and moisture and would not inhibit salamander movement over the forest floor.
Direct estimates of downslope deadwood movement over 30 years in a temperature forest illustrate impacts of treefall on forest ecosystem dynamics
Authors: Oberle Brad , Milo Amy M. , Myers Jonathan A. , Walton Maranda L. , Young Darcy F. , Zanne Amy E.
Published: December 2015

Deadwood plays important roles in forest ecosystems by storing carbon, influencing hydrology, and provisioning countless organisms. Models for these processes often assume that deadwood does not move and ignore redistribution that occurs when trees fall. To evaluate the effects of treefall, we provide the first direct estimates for the magnitude, direction, and drivers of deadwood movement in a long-term oak–hickory forest dynamics plot in Missouri, USA. Among 1871 total pieces of deadwood, logs today pointed downslope more often than branches and occurred at lower elevation than snags. Of these, 477 logs retained tags from which we reconstructed movement using new formulae for reconciling survey coordinates and calculating log shape. Relocated logs occurred at lower elevation than their original rooting location, with the magnitude of the drop dependent on log size, degree of decay, and slope. Although changes in elevation were modest, the log centroids moved up to several meters horizontally. Consequently, as large trees fall, they predictably redistribute deadwood downhill, suggesting that models of deadwood dynamics in small inventory plots may gain accuracy by incorporating import and export along with recruitment and decay. We highlight implications of small-scale deadwood movement for forest inventories, carbon dynamics, and biodiversity.
Sparse Sums of Positive Semidefinite Matrices
Authors: Silva Marcel K. De Carli , Harvey Nicholas J. A. , Sato Cristiane M.
Published: December 2015

Many fast graph algorithms begin by preprocessing the graph to improve its sparsity. A common form of this is spectral sparsification, which involves removing and reweighting the edges of the graph while approximately preserving its spectral properties. This task has a more general linear algebraic formulation in terms of approximating sums of rank-one matrices. This article considers a more general task of approximating sums of symmetric, positive semidefinite matrices of arbitrary rank. We present two deterministic, polynomial time algorithms for solving this problem. The first algorithm applies the pessimistic estimators of Wigderson and Xiao, and the second involves an extension of the method of Batson, Spielman, and Srivastava. These algorithms have several applications, including sparsifiers of hypergraphs, sparse solutions to semidefinite programs, sparsifiers of unique games, and graph sparsifiers with various auxiliary constraints.
Randomization-Based Intrusion Detection System for Advanced Metering Infrastructure*
Authors: Ali Muhammad Qasim , Al-Shaer Ehab
Published: December 2015

Smart grid deployment initiatives have been witnessed in recent years. Smart grids provide bidirectional communication between meters and head-end systems through Advanced Metering Infrastructure (AMI). Recent studies highlight the threats targeting AMI. Despite the need for tailored Intrusion Detection Systems (IDSs) for smart grids, very limited progress has been made in this area. Unlike traditional networks, smart grids have their own unique challenges, such as limited computational power devices and potentially high deployment cost, that restrict the deployment options of intrusion detectors. We show that smart grids exhibit deterministic and predictable behavior that can be accurately modeled to detect intrusion. However, it can also be leveraged by the attackers to launch evasion attacks. To this end, in this article, we present a robust mutation-based intrusion detection system that makes the behavior unpredictable for the attacker while keeping it deterministic for the system. We model the AMI behavior using event logs collected at smart collectors, which in turn can be verified using the invariant specifications generated from the AMI behavior and mutable configuration. Event logs are modeled using fourth-order Markov chain and specifications are written in Linear Temporal Logic (LTL). To counter evasion and mimicry attacks, we propose a configuration randomization module. The approach provides robustness against evasion and mimicry attacks; however, we discuss that it still can be evaded to a certain extent. We validate our approach on a real-world dataset of thousands of meters collected at the AMI of a leading utility provider.
Integrated Parallel Sentence and Fragment Extraction from Comparable Corpora
Authors: Chu Chenhui , Nakazawa Toshiaki , Kurohashi Sadao
Published: December 2015

Parallel corpora are crucial for statistical machine translation (SMT); however, they are quite scarce for most language pairs and domains. As comparable corpora are far more available, many studies have been conducted to extract either parallel sentences or fragments from them for SMT. In this article, we propose an integrated system to extract both parallel sentences and fragments from comparable corpora. We first apply parallel sentence extraction to identify parallel sentences from comparable sentences. We then extract parallel fragments from the comparable sentences. Parallel sentence extraction is based on a parallel sentence candidate filter and classifier for parallel sentence identification. We improve it by proposing a novel filtering strategy and three novel feature sets for classification. Previous studies have found it difficult to accurately extract parallel fragments from comparable sentences. We propose an accurate parallel fragment extraction method that uses an alignment model to locate the parallel fragment candidates and an accurate lexicon-based filter to identify the truly parallel fragments. A case study on the Chinese--Japanese Wikipedia indicates that our proposed methods outperform previously proposed methods, and the parallel data extracted by our system significantly improves SMT performance.
A Survey on Energy Efficiency in P2P Systems
Authors: Brienza Simone , Cebeci Sena Efsun , Masoumzadeh Seyed Saeid , Hlavacs Helmut , Özkasap Öznur , Anastasi Giuseppe
Published: December 2015

Several Peer-to-Peer (P2P) protocols and applications have been developed to allow file distribution/sharing, video and music streaming, and data and information dissemination. These P2P systems are regularly used by a large number of users, both in desktop and mobile environments, and they generate a remarkable portion of the overall Internet traffic. However, many common P2P protocols and applications were designed neglecting the energy problem. In fact, they often require always-on devices in order to work properly, thus producing significant energy waste. The problem is even more relevant in the mobile context, since the battery lifetime of mobile devices is limited. Therefore, energy efficiency in P2P systems is a highly debated topic in the literature. New P2P approaches—more energy efficient than traditional client/server solutions—have been proposed. In addition, several improvements to existing P2P protocols have been introduced to reduce their energy consumption. In this article, we present a general taxonomy to classify state-of-the-art approaches to the energy problem in P2P systems and applications. Then, we survey the main solutions available in the literature, focusing on three relevant classes of P2P systems and applications:
file sharing/distribution
,
content streaming,
and
epidemics
. Furthermore, we outline open issues and provide future research guidelines for each class of P2P systems.
A Taxonomy of Attacks and a Survey of Defence Mechanisms for Semantic Social Engineering Attacks
Authors: Heartfield Ryan , Loukas George
Published: December 2015

Social engineering
is used as an umbrella term for a broad spectrum of computer exploitations that employ a variety of attack vectors and strategies to psychologically manipulate a user. Semantic attacks are the specific type of social engineering attacks that bypass technical defences by actively manipulating object characteristics, such as platform or system applications, to deceive rather than directly attack the user. Commonly observed examples include obfuscated URLs, phishing emails, drive-by downloads, spoofed websites and scareware to name a few. This article presents a taxonomy of semantic attacks, as well as a survey of applicable defences. By contrasting the threat landscape and the associated mitigation techniques in a single comparative matrix, we identify the areas where further research can be particularly beneficial.
A Survey of Automatic Protocol Reverse Engineering Tools
Authors: Narayan John , Shukla Sandeep K. , Clancy T. Charles
Published: December 2015

Computer network protocols define the rules in which two entities communicate over a network of unique hosts. Many protocol specifications are unknown, unavailable, or minimally documented, which prevents thorough analysis of the protocol for security purposes. For example, modern botnets often use undocumented and unique application-layer communication protocols to maintain command and control over numerous distributed hosts. Inferring the specification of closed protocols has numerous advantages, such as intelligent deep packet inspection, enhanced intrusion detection system algorithms for communications, and integration with legacy software packages. The multitude of closed protocols coupled with existing time-intensive reverse engineering methodologies has spawned investigation into automated approaches for reverse engineering of closed protocols. This article summarizes and organizes previously presented automatic protocol reverse engineering tools by approach. Approaches that focus on reverse engineering the finite state machine of a target protocol are separated from those that focus on reverse engineering the protocol format.
Highlights of broadening participation research at RESPECT'15
Authors: Barnes Tiffany , Payton Jamie , Guzdial Mark
Published: December 2015

RESPECT'15, the first international conference of the IEEE Computer Society Special Technical Community on Broadening Participation, was held this August in conjunction with the STARS Celebration in Charlotte, NC. Themes from the conference provide research-based evidence of what's working and what's left to be done to support broadening participation (BP) in computing. The percentage of women in undergraduate programs in computing continues to decline, but there are bright spots, such as the rise of women in interdisciplinary computing programs and the increase in the number of Hispanic/Latina women in computing. BP programs that build community, competence, and identity are effective, and have a higher impact on people from underrepresented groups, as highlighted in RESPECT'15 papers on the STARS Computing Corps, Georgia Tech's Project Rise Up for CS, NCWIT's Aspirations in Computing, and undergraduate research. Many effective BP interventions intentionally engage people from underrepresented groups in designing and implementing the change. The RESPECT'15 proceedings will be available soon in IEEE Xplore and the ACM Digital Library.
Risk Assessment in Criminal Sentencing
Authors: Monahan John , Skeem Jennifer L.
Published: December 2015

The past several years have seen a surge of interest in using risk assessment in criminal sentencing, both to reduce recidivism by incapacitating or treating high-risk offenders and to reduce prison populations by diverting low-risk offenders from prison. We begin by sketching jurisprudential theories of sentencing, distinguishing those that rely on risk assessment from those that preclude it. We then characterize and illustrate the varying roles that risk assessment may play in the sentencing process. We clarify questions regarding the various meanings of “risk” in sentencing and the appropriate time to assess the risk of convicted offenders. We conclude by addressing four principal problems confronting risk assessment in sentencing: conflating risk and blame, barring individual inferences based on group data, failing adequately to distinguish risk assessment from risk reduction, and ignoring whether, and if so, how, the use of risk assessment in sentencing affects racial and economic disparities in imprisonment.
Roles and Regulation of Renal K Channels
Authors: Welling Paul A.
Published: December 2015

More than two dozen types of potassium channels, with different biophysical and regulatory properties, are expressed in the kidney, influencing renal function in many important ways. Recently, a confluence of discoveries in areas from human genetics to physiology, cell biology, and biophysics has cast light on the special function of five different potassium channels in the distal nephron, encoded by the genes KCNJ1, KCNJ10, KCNJ16, KCNMA1, and KCNN3. Research aimed at understanding how these channels work in health and go awry in disease has transformed our understanding of potassium balance and provided new insights into mechanisms of renal sodium handling and the maintenance of blood pressure. This review focuses on recent advances in this rapidly evolving field.
A Resource for the Transcriptional Signature of Bona Fide Trophoblast Stem Cells and Analysis of Their Embryonic Persistence
Authors: Kuales Georg , Weiss Matthias , Sedelmeier Oliver , Pfeifer Dietmar , Arnold Sebastian J.
Published: December 2015

Trophoblast stem cells (TSCs) represent the multipotent progenitors that give rise to the different cells of the embryonic portion of the placenta. Here, we analysed the expression of key TSC transcription factorsCdx2,Eomes, andElf5in the early developing placenta of mouse embryos and in cultured TSCs and reveal surprising heterogeneity in protein levels. We analysed persistence of TSCs in the early placenta and find that TSCs remain in the chorionic hinge until E9.5 and are lost shortly afterwards. To define the transcriptional signature of bona fide TSCs, we used inducible gain- and loss-of-function alleles ofEomesorCdx2, andEomesGFP, to manipulate and monitor the core maintenance factors of TSCs, followed by genome-wide expression profiling. Combinatorial analysis of resulting expression profiles allowed for defining novel TSC marker genes that might functionally contribute to the maintenance of the TSC state. Analyses by qRT-PCR andin situhybridisation validated novel TSC- and chorion-specific marker genes, such asBok/Mtd, Cldn26, Duox2, Duoxa2, Nr0b1, andSox21. Thus, these expression data provide a valuable resource for the transcriptional signature of bona fide and early differentiating TSCs and may contribute to an increased understanding of the transcriptional circuitries that maintain and/or establish stemness of TSCs.
Porous Silicates Modified with Zirconium Oxide and Sulfate Ions for Alcohol Dehydration Reactions
Authors: Esteban Benito Heriberto , García Alamilla Ricardo , Hernández Enríquez Juan Manuel , Paraguay Delgado Francisco , Lardizabal Gutiérrez Daniel , García Pedro
Published: December 2015

Porous silicates were synthesized by a nonhydrothermal method, using sodium silicate as a source of silica and cetyltrimethylammonium bromide as a template agent. Catalysts were characterized using thermogravimetric analysis, N2physisorption, X-ray diffraction, FTIR spectroscopy, pyridine adsorption, potentiometric titration withn-butylamine, scanning electronic microscopy, and transmission electronic microscopy. The surface area of the materials synthesized was greater than 800 m2/g. The introduction of zirconium atoms within the porous silicates increased their acid strength from −42 to 115 mV, while the addition of sulfate ions raised this value to 470 mV. The catalytic activity for the dehydration of alcohols yields conversions of up to 70% for ethanol and 30% for methanol.
Uncommon Trimethoxylated Flavonol Obtained fromRubus rosaefoliusLeaves and Its Antiproliferative Activity
Authors: Petreanu Marcel , Ferreira Emili Kamila , Sagaz Ana Paula M. , Vendramini-Costa Débora B. , Ruiz Ana Lúcia T. G. , De Carvalho João Ernesto , Campos Adriana , Cechinel Filho Valdir , Delle Monache Franco , Niero Rivaldo
Published: December 2015

This study shows the evaluation the antiproliferative effect of the extract, fractions, and uncommon compounds isolated fromR. rosaefoliusleaves. The compounds were identified by conventional spectroscopic methods such as NMR-H1and C13and identified as 5,7-dihydroxy-6,8,4′-trimethoxyflavonol (1), 5-hydroxy-3,6,7,8,4′-pentamethoxyflavone (2), and tormentic acid (3). Both hexane and dichloromethane fractions showed selectivity for multidrug-resistant ovary cancer cell line (NCI-ADR/RES) with total growth inhibition values of 11.1 and 12.6 μg/ml, respectively. Compound1also showed selective activity against the same cell line (18.8 μg/ml); however, it was especially effective against glioma cells (2.8 μg/ml), suggesting that this compound may be involved with thein vitroantiproliferative action.
Derivative Spectrophotometric Methods for the Analysis and Stability Studies of Colistin Sulphate
Authors: Mutasim Elimam Mohammed , Wagiealla Shantier Shaza , Ahmed Gadkariem Elrasheed , Awadalla Mohamed Magdi
Published: December 2015

Simple spectrophotometric methods were developed for the quantitative determination of colistin sulphate in bulk and dosage forms. The methods were based on the measurement of first and second derivative spectra of colistin sulphate at 298 nm and 318 nm, respectively. Beer’s law was obeyed in the concentration range 800–4000 IU/mL with good correlation coefficient (not less than 0.998) for both methods. The developed first derivative spectrophotometric method was then selected to study the degradation behavior of colistin sulphate in alkaline media at different temperatures as the second derivative method failed to give reproducible results for the stability study. The pH-rate profile indicates a first-order dependence of the degradation rate on [OH−] at pH ranging between 8 and 11. The obtained results for the photochemical study reflected photostability of colistin sulphate.
Electrical Stimulation Promotes Cardiac Differentiation of Human Induced Pluripotent Stem Cells
Authors: Hernández Damián , Millard Rodney , Sivakumaran Priyadharshini , Wong Raymond C. B. , Crombie Duncan E. , Hewitt Alex W. , Liang Helena , Hung Sandy S. C. , Pébay Alice , Shepherd Robert K. , Dusting Gregory J. , Lim Shiang Y.
Published: December 2015

Background. Human induced pluripotent stem cells (iPSCs) are an attractive source of cardiomyocytes for cardiac repair and regeneration. In this study, we aim to determine whether acute electrical stimulation of human iPSCs can promote their differentiation to cardiomyocytes. Methods. Human iPSCs were differentiated to cardiac cells by forming embryoid bodies (EBs) for 5 days. EBs were then subjected to brief electrical stimulation and plated down for 14 days. Results. In iPS(Foreskin)‐2 cell line, brief electrical stimulation at 65 mV/mm or 200 mV/mm for 5 min significantly increased the percentage of beating EBs present by day 14 after plating. Acute electrical stimulation also significantly increased the cardiac gene expression of ACTC1, TNNT2, MYH7, and MYL7. However, the cardiogenic effect of electrical stimulation was not reproducible in another iPS cell line, CERA007c6. Beating EBs from control and electrically stimulated groups expressed various cardiac‐specific transcription factors and contractile muscle markers. Beating EBs were also shown to cycle calcium and were responsive to the chronotropic agents, isoproterenol and carbamylcholine, in a concentration‐dependent manner. Conclusions. Our results demonstrate that brief electrical stimulation can promote cardiac differentiation of human iPS cells. The cardiogenic effect of brief electrical stimulation is dependent on the cell line used.
Hepatocyte Growth Factor Effects on Mesenchymal Stem Cells Derived from Human Arteries: A Novel Strategy to Accelerate Vascular Ulcer Wound Healing
Authors: Valente Sabrina , Ciavarella Carmen , Pasanisi Emanuela , Ricci Francesca , Stella Andrea , Pasquinelli Gianandrea
Published: December 2015

Vascular ulcers are a serious complication of peripheral vascular disease, especially in diabetics. Several approaches to treat the wounds are proposed but they show poor outcomes and require long healing times. Hepatocyte Growth Factor/Scatter Factor (HGF/SF) is a pleiotropic cytokine exerting many biological activities through the c‐Met receptor. This study was aimed at verifying whether HGF/SF influences proliferation, migration, and angiogenesis on mesenchymal stem cells isolated from human arteries (hVW‐MSCs). hVW‐MSCs were exposed to NIBSC HGF/SF (2.5, 5, 10, and 70 ng/mL) from 6 hrs to 7 days. HGF and c‐MET mRNA and protein expression, cell proliferation (Alamar Blue and Ki–67 assay), migration (scratch and transwell assays), and angiogenesis (Matrigel) were investigated. hVW‐MSCs displayed stemness features and expressed HGF and c‐MET. HGF/SF did not increase hVW‐MSC proliferation, whereas it enhanced the cell migration, the formation of capillary‐like structures, and the expression of angiogenic markers (vWF, CD31, and KDR). The HGF/SF effects on hVW‐MSC migration and angiogenic potential are of great interest to accelerate wound healing process. Local delivery of HGF/SF could therefore improve the healing of unresponsive vascular ulcers.
Maladaptive Modulations of NLRP3 Inflammasome and Cardioprotective Pathways Are Involved in Diet‐Induced Exacerbation of Myocardial Ischemia/Reperfusion Injury in Mice
Authors: Mastrocola Raffaella , Collino Massimo , Penna Claudia , Nigro Debora , Chiazza Fausto , Fracasso Veronica , Tullio Francesca , Alloatti Giuseppe , Pagliaro Pasquale , Aragno Manuela
Published: December 2015

Excessive fatty acids and sugars intake is known to affect the development of cardiovascular diseases, including myocardial infarction. However, the underlying mechanisms are ill defined. Here we investigated the balance between prosurvival and detrimental pathways within the heart of C57Bl/6 male mice fed a standard diet (SD) or a high‐fat high‐fructose diet (HFHF) for 12 weeks and exposed to cardiac ex vivo ischemia/reperfusion (IR) injury. Dietary manipulation evokes a maladaptive response in heart mice, as demonstrated by the shift of myosin heavy chain isoform content from α to β, the increased expression of the Nlrp3 inflammasome and markers of oxidative metabolism, and the downregulation of the hypoxia inducible factor‐ (HIF‐)2α and members of the Reperfusion Injury Salvage Kinases (RISK) pathway. When exposed to IR, HFHF mice hearts showed greater infarct size and lactic dehydrogenase release in comparison with SD mice. These effects were associated with an exacerbated overexpression of Nlrp3 inflammasome, resulting in marked caspase‐1 activation and a compromised activation of the cardioprotective RISK/HIF‐2α pathways. The common mechanisms of damage here reported lead to a better understanding of the cross‐talk among prosurvival and detrimental pathways leading to the development of cardiovascular disorders associated with metabolic diseases.
The Effect of Leonurus sibiricus Plant Extracts on Stimulating Repair and Protective Activity against Oxidative DNA Damage in CHO Cells and Content of Phenolic Compounds
Authors: Sitarek Przemysław , Skała Ewa , Wysokińska Halina , Wielanek Marzena , Szemraj Janusz , Toma Monika , Śliwiński Tomasz
Published: December 2015

Leonurus sibiricus L. has been used as a traditional and medicinal herb for many years in Asia and Europe. This species is known to have antibacterial, anti‐inflammatory, and antioxidant activity and has demonstrated a reduction of intracellular reactive oxygen species. All tested extracts of L. sibiricus showed protective and DNA repair stimulating effects in Chinese hamster ovary (CHO) cells exposed to H2O2. Preincubation of the CHO cells with 0.5 mg/mL of plant extracts showed increased expression level of antioxidant genes (SOD2, CAT, and GPx). LC‐MS/MS and HPLC analyses revealed the presence of nine phenolic compounds in L. sibiricus plant extracts: catechin, verbascoside, two flavonoids (quercetin and rutin), and five phenolic acids (4‐hydroxybenzoic acid, chlorogenic acid, caffeic acid, p‐coumaric acid, and ferulic acid). The roots and aerial parts of in vitro L. sibiricus plant extracts, which had the strongest antioxidant properties, may be responsible for stimulating CHO cells to repair oxidatively induced DNA damage, as well as protecting DNA via enhanced activation of the antioxidant genes (SOD2, CAT, and GPx) regulating intracellular antioxidant capacity. The content of phenolic compounds in in vitro raised plants was greater than the levels found in plants propagated from seeds.
Cdk5r1 Overexpression Induces Primaryβ-Cell Proliferation
Authors: Draney Carrie , Hobson Amanda E. , Grover Samuel G. , Jack Benjamin O. , Tessem Jeffery S.
Published: December 2015

Decreasedβ-cell mass is a hallmark of type 1 and type 2 diabetes. Islet transplantation as a method of diabetes therapy is hampered by the paucity of transplant ready islets. Understanding the pathways controlling islet proliferation may be used to increase functionalβ-cell mass through transplantation or by enhanced growth of endogenousβ-cells. We have shown that the transcription factor Nkx6.1 inducesβ-cell proliferation by upregulating the orphan nuclear hormone receptors Nr4a1 and Nr4a3. Using expression analysis to define Nkx6.1-independent mechanisms by which Nr4a1 and Nr4a3 induceβ-cell proliferation, we demonstrated that cyclin-dependent kinase 5 regulatory subunit 1 (Cdk5r1) is upregulated by Nr4a1 and Nr4a3 but not by Nkx6.1. Overexpression of Cdk5r1 is sufficient to induce primary ratβ-cell proliferation while maintaining glucose stimulated insulin secretion. Overexpression of Cdk5r1 inβ-cells confers protection against apoptosis induced by etoposide and thapsigargin, but not camptothecin. The Cdk5 kinase complex inhibitor roscovitine blocks islet proliferation, suggesting that Cdk5r1 mediatedβ-cell proliferation is a kinase dependent event. Overexpression of Cdk5r1 results in pRb phosphorylation, which is inhibited by roscovitine treatment. These data demonstrate that activation of the Cdk5 kinase complex is sufficient to induceβ-cell proliferation while maintaining glucose stimulated insulin secretion.
Connexin-Based Therapeutics and Tissue Engineering Approaches to the Amelioration of Chronic Pancreatitis and Type I Diabetes: Construction and Characterization of a Novel Prevascularized Bioartificial Pancreas
Authors: Rhett J. Matthew , Wang Hongjun , Bainbridge Heather , Song Lili , Yost Michael J.
Published: December 2015

Total pancreatectomy and islet autotransplantation is a cutting-edge technique to treat chronic pancreatitis and postoperative diabetes. A major obstacle has been low islet cell survival due largely to the innate inflammatory response. Connexin43 (Cx43) channels play a key role in early inflammation and have proven to be viable therapeutic targets. Even if cell death due to early inflammation is avoided, insufficient vascularization is a primary obstacle to maintaining the viability of implanted cells. We have invented technologies targeting the inflammatory response and poor vascularization: a Cx43 mimetic peptide that inhibits inflammation and a novel prevascularized tissue engineered construct. We combined these technologies with isolated islets to create a prevascularized bioartificial pancreas that is resistant to the innate inflammatory response. Immunoconfocal microscopy showed that constructs containing islets express insulin and possess a vascular network similar to constructs without islets. Glucose stimulated islet-containing constructs displayed reduced insulin secretion compared to islets alone. However, labeling for insulin post-glucose stimulation revealed that the constructs expressed abundant levels of insulin. This discrepancy was found to be due to the expression of insulin degrading enzyme. These results suggest that the prevascularized bioartificial pancreas is potentially a tool for improving long-term islet cell survivalin vivo.
Effect on Multipotency and Phenotypic Transition of Unrestricted Somatic Stem Cells from Human Umbilical Cord Blood after Treatment with Epigenetic Agents
Authors: Ghanjati Foued , Santourlidis Simeon
Published: December 2015

The epigenetic mechanism of DNA methylation is of central importance for cellular differentiation processes. Unrestricted somatic stem cells (USSCs) from human umbilical cord blood, which have a broad differentiation spectrum, reside in an uncommitted epigenetic state with partial methylation of the regulatory region of the gene coding for the pluripotency master regulator OCT4. Thus we hypothesized that further opening of this “poised” epigenetic state could broaden the differentiation potential of USSCs. Here we document that USSCs drastically change their phenotype after treatment by a new elaborated cultivation protocol which utilizes the DNA hypomethylating compound 5′‐aza‐2‐deoxycytidine (5‐Aza‐CdR) and the histone deacetylase inhibitor trichostatin A (TSA). This treatment leads to a new stable, spheroid‐forming cell type which we have named SpheUSSC. These cells can be stably propagated over at least 150 cell divisions, express OCT4, retain the potential to undergo osteogenic differentiation, and have additionally acquired the ability to uniformly differentiate into adipocytes, unlike the source USSC population. Here we describe our treatment protocol and provide evidence that it induces a dedifferentiation step and concomitantly the acquisition of an extended differentiation capability of the new SpheUSSC type.
Cholesterol Enhances the Toxic Effect of Ethanol and Acetaldehyde in Primary Mouse Hepatocytes
Authors: López-Islas Anayelly , Chagoya-Hazas Victoria , Pérez-Aguilar Benjamin , Palestino-Domínguez Mayrel , Souza Verónica , Miranda Roxana U. , Bucio Leticia , Gómez-Quiroz Luis Enrique , Gutiérrez-Ruiz María-Concepción
Published: December 2015

Obesity and alcohol consumption are risk factors for hepatic steatosis, and both commonly coexist. Our objective was to evaluate the effect of ethanol and acetaldehyde on primary hepatocytes obtained from mice fed for two days with a high cholesterol (HC) diet. HC hepatocytes increased lipid and cholesterol content. HC diet sensitized hepatocytes to the toxic effect of ethanol and acetaldehyde. Cyp2E1 content increased with HC diet, as well as in those treated with ethanol or acetaldehyde, while the activity of this enzyme determined in microsomes increased in the HC and in all ethanol treated hepatocytes, HC and CW. Oxidized proteins were increased in the HC cultures treated or not with the toxins. Transmission electron microscopy showed endoplasmic reticulum (ER) stress and megamitochondria in hepatocytes treated with ethanol as in HC and the ethanol HC treated hepatocytes. ER stress determined by PERK content was increased in ethanol treated hepatocytes from HC mice and CW. Nuclear translocation of ATF6 was observed in HC hepatocytes treated with ethanol, results that indicate that lipids overload and ethanol treatment favor ER stress. Oxidative stress, ER stress, and mitochondrial damage underlie potential mechanisms for increased damage in steatotic hepatocyte treated with ethanol.