bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of abandonment on plant diversity in semi‐natural grasslands along soil and climate gradients
Authors: Wehn Sølvi , Taugourdeau Simon , Johansen Line , Hovstad Knut Anders
Published: May 2017

Questions

What are the effects of abandonment on plant diversity in semi‐natural grasslands? Do the effects of abandonment on taxonomic and functional diversity vary along environmental gradients of climate and soil?

Location

West and mid‐Norway.

Methods

Plant composition was surveyed in 110 subplots of 4 m2 in 14 sites across grazed and abandoned semi‐natural grasslands. Climate data were extracted and soil composition analysed. To reduce the number of explanatory variables and deal with collinearity, we performed PCA. Data on the plant species vegetative height (H), leaf dry matter content (LDMC), specific leaf area (SLA), seed mass (SM) and number of seeds per plant (SNP) for 175 species were extracted from the LEDA database. Measures of plant diversity (species richness, CWM of functional traits and functional diversity (evenness and range)) were calculated for each subplot. To estimate the effects of abandonment on plant diversity and examine how these effects are moderated by gradients in soil and climate, we fitted mixed models to the data including site as a random effect.

Results

Species richness in the subplots was lower in abandoned semi‐natural grasslands, especially on more calcareous soils. CWM H, LDMC and SM were higher in abandoned semi‐natural grasslands. CWM LDMC was only higher in the driest subplots. The ranges in H, SLA and SM, as well as evenness in LDMC were also higher in abandoned semi‐natural grasslands,but the range in LDMC was lower.

Conclusions

It is important to assess both taxonomic and functional diversity to understand ecosystem processes. The species pool in ecosystems influenced by a long history of intermediate grazing includes a high proportion of low stature, grazing‐tolerant plant species. Abandonment of extensive land‐use practices will cause a decline in taxonomic diversity (plant species richness) in such systems due to increased abundance of plants with high stature that outcompete the lower, grazing‐tolerant plants. This process is predominant especially if moisture, soil fertility and pH are at intermediate levels. Changes in species communities due to abandonment will also influence ecosystem functioning, such as nutrient turnover and fodder production resilience.
The practice of caricature in 18th‐century Britain
Authors: Taylor David Francis
Published: May 2017

This essay offers a survey of critical studies of caricature—as in the art of physiognomic exaggeration and distortion—in 18th‐century Britain. It reviews scholarship that has grappled with such questions as: what is caricature and how do we recognize it? Why caricature? How does caricature make itself felt within the hierarchies of 18th‐century British culture? When and why does it emerge in Britain as a dominant mode of visual satire? What, in this cultural matrix, is its politics, if it can be said to have a politics at all? And can we speak of caricature as a verbal practice as much as a graphic one? This essay begins with a consideration of early efforts to formulate a theory of caricature before turning to more recent contributions to the field that have sought to map the cultural politics of caricature's presence within 18th‐century graphic satire. In a final section, it then considers the work undertaken to trace practices of caricature on stage and in the novel.
Inductive constructivism and national identities: letting the data speak
Authors: Alemán José , Woods Dwayne
Published: May 2017

The literature on nationalism has provided conceptual definitions of national identity that supposedly delineate its underlying empirical manifestations. A binary conceptualization (civic versus ethnic) is widely used by scholars. There are confusion and ambiguity in the definition, however, as well as sense that the prevailing schema does not adequately capture the fluidity and complexity of the phenomenon. We posit that abstract conceptual definitions do not validly capture the way individuals actually experience identification with their nations. Using a methodology that models the distribution of responses to survey questionnaires – latent class analysis – we demonstrate that individuals cluster in two different groups in the way they identify with their nations: nationalists are strongly attached to the nation and more exacting in their criteria for membership, while cosmopolitans display lower identification with the nation and are more inclusive in their desired criteria of membership. These classes are to some degree fluid across indicators and nations. Broadly speaking, however, the configurations are comparable cross‐nationally.
Heterogeneity of enterochromaffin cells within the gastrointestinal tract
Authors: Diwakarla S. , Fothergill L. J. , Fakhry J. , Callaghan B. , Furness J. B.
Published: May 2017

Enterochromaffin cells were the first endocrine cells of the gastrointestinal tract to be chemically distinguished, almost 150 years ago. It is now known that the chromaffin reaction of these cells was due to their content of the reactive aromatic amine, 5‐hydroxytryptamine (5‐HT, also known as serotonin). They have commonly been thought to be a special class of gut endocrine cells (enteroendocrine cells) that are distinct from the enteroendocrine cells that contain peptide hormones. The study by Martin et al. in the current issue of this journal reveals that the patterns of expression of nutrient receptors and transporters differ considerably between chromaffin cells of the mouse duodenum and colon. However, even within regions, chromaffin cells differ; in the duodenum there are chromaffin cells that contain both secretin and 5‐HT, cholecystokinin and 5‐HT, and all three of secretin, cholecystokinin, and 5‐HT. Moreover, the ratios of these different cell types differ substantially between species. And, in terms of function, 5‐HT has many roles, including in appetite, motility, fluid secretion, release of digestive enzymes and bone metabolism. The paper thus emphasizes the need to define the many different classes of enterochromaffin cells and relate this to their roles.
Change in over‐refraction after scleral lens settling on average corneas
Authors: Bray Chelsea , Britton Stephanie , Yeung Debby , Haines Lacey , Sorbara Luigina
Published: May 2017

Purpose

The purpose of this study was to determine the change in over‐refraction, if any, after a scleral lens settled on the eye for 6–8 h.

Methods

Sixteen patients of varying refractive errors and normal corneal curvatures (measured with Pentacam™ Oculus) were fitted with trial Mini‐Scleral Design (MSD) scleral lenses (15.8 mm diameter) in one eye. The sagittal depths of the scleral lenses were selected by adding 350 μm to the corneal sagittal heights measured at a chord length of 15 mm with the Visante™ optical coherence tomographer (OCT) anterior segment scans and picking the closest available trial lens in the set. Initial measurements were taken 30 min after lens insertion and included an auto‐refraction, subjective refraction, and best sphere refraction over the contact lens. Visual acuities and Visante™ OCT anterior segment scans were also taken. These measurements were repeated after 6–8 h of lens wear.

Results

Over the trial wearing period, the average change in the spherical component of the over‐refraction was +0.06 D (S.D. 0.17) (p = 0.16). The average change in cylinder was +0.04 D (S.D. 0.19) (p = 0.33). The average absolute change in axis was 1.06° (S.D. 12.11) (p = 0.74). The average change in best sphere was +0.13 ± 0.30 D (p = 0.12). There was no significant change in visual acuity with the best sphere over‐refraction over the 6–8 h wearing period. There was a significant change in central corneal clearance over the wearing period of 83 μm (S.D. 22) (p < 0.0001).

Conclusion

Despite a significant change in the central corneal clearance due to thinning of the fluid reservoir as the scleral lens settled (an average decrease of 83 μm after wearing the lenses for 6–8 h), there was not a statistically significant change in the subjective over‐refraction (sphere, cylinder, and axis) or best sphere or visual acuity. This study has confirmed that there is no link between reduction in central corneal clearance and change in over‐refraction for average corneas.
Low fossilization potential of keratin protein revealed by experimental taphonomy
Authors: Saitta Evan T. , Rogers Chris , Brooker Richard A. , Abbott Geoffrey D. , Kumar Sumit , O'Reilly Shane S. , Donohoe Paul , Dutta Suryendu , Summons Roger E. , Vinther Jakob
Published: May 2017

Recent studies have suggested the presence of keratin in fossils dating back to the Mesozoic. However, ultrastructural studies revealing exposed melanosomes in many fossil keratinous tissues suggest that keratin should rarely, if ever, be preserved. In this study, keratin's stability through diagenesis was tested using microbial decay and maturation experiments on various keratinous structures. The residues were analysed using pyrolysis‐gas chromatography‐mass spectrometry and compared to unpublished feather and hair fossils and published fresh and fossil melanin from squid ink. Results show that highly matured feathers (200–250°C/250 bars/24 h) become a volatile‐rich, thick fluid with semi‐distinct pyrolysis compounds from those observed in less degraded keratins (i.e. fresh, decayed, moderately matured, and decayed and moderately matured) suggesting hydrolysis of peptide bonds and potential degradation of free amino acids. Neither melanization nor keratin (secondary) structure (e.g. ⍺‐ vs β‐keratin) produced different pyrograms; melanin pyrolysates are largely a subset of those from proteins, and proteins have characteristic pyrolysates. Analyses of fossil fur and feather found a lack of amides, succinimide and piperazines (present even in highly matured keratin) and showed pyrolysis compounds more similar to fossil and fresh melanin than to non‐matured or matured keratin. Although the highly matured fluid was not water soluble at room temperature, it readily dissolved at elevated temperatures easily attained during diagenesis, meaning it could leach away from the fossil. Future interpretations of fossils must consider that calcium phosphate and pigments are the only components of keratinous structures known to survive fossilization in mature sediments.
Indeterministic Causation and Two Patches for the Pairing Argument
Authors: Saad Bradford
Published: May 2017

The pairing argument aims to demonstrate the impossibility of non‐spatial objects (including minds) standing in causal relations. Its chief premises are (roughly) that causation requires pairing relations between causes and effects and that pairing relations require spatial relations. Critics have argued that the first claim suffers from counterexamples involving indeterministic causation. After briefly rehearsing the pairing argument and the objection from indeterministic causation, I offer two ways of revising the pairing argument to meet the objection from indeterministic causation.
Stimulation of the L2–L3 Dorsal Root Ganglia Induces Effective Pain Relief in the Low Back
Authors: Huygen Frank , Liem Liong , Cusack William , Kramer Jeffery
Published: May 2017

Introduction

Chronic low back pain affects millions of people worldwide and can arise through a variety of clinical origins. In the case of failed back surgery syndrome (FBSS), previous surgical procedures can contribute to low back pain that is often unresponsive to intervention. Although spinal cord stimulation (SCS) can be an effective treatment modality, it does not provide sufficient pain relief for some intractable cases. Recently, alternative neuromodulation options have been developed, including dorsal root ganglion (DRG) stimulation. The objective of this report is to further investigate these clinical observations.

Methods

Twelve patients with significant chronic discogenic low back pain due to FBSS were included. All subjects underwent implantation of DRG stimulation systems that had at least 1 lead placed at L2 or L3. Subjects’ pain ratings, mood, and quality of life were tracked prospectively for up to 12 months.

Results

More than half of subjects reported 50% or better pain relief in the low back, and the average low back pain relief was 45.5% at 12 months. Concomitant reductions in overall pain, leg pain, pain interference, mood, and quality of life were also found.

Discussion

For the studied population, DRG stimulation at the L2–L3 levels was effective at relieving low back pain. These reductions in pain were associated with improvements in quality of life. Thus, DRG stimulation at these levels may be effective for low back pain by recruiting both segmental and nonsegmental neural pathways that are not otherwise accessible via traditional SCS.
Toxic epidermal necrolysis in a child 6 months post‐hematopoietic stem cell transplantation
Authors: Oba Utako , Yamada Hiroshi , Suenobu So‐ichi , Nakamura Yusuke , Ito Akiko , Hatano Yutaka , Itonaga Nobuyoshi , Ohshima Kouichi , Koga Yuhki , Ohga Shouichi , Ihara Kenji
Published: May 2017

TEN is a rare and critical disease mostly caused by drugs. It is mediated by activated CD8+ T cells that cause keratinocyte apoptosis with the assistance of cytokines/chemokines. We herein report a pediatric case of TEN after allogeneic HSCT with precursor B‐cell acute lymphoblastic leukemia (pre‐B‐ALL) in second complete remission. Although we did not evaluate the T‐cell subpopulation in blood or skin lesion of the patient, an imbalanced immune reconstitution after HSCT might additively contribute to the development of TEN.
Postracial Society as Social Fantasy: Black Communities Trapped Between Racism and a Struggle for Political Recognition
Authors: Zevnik Andreja
Published: May 2017

The article discusses postracial society as social fantasy. It opens with a discussion of the lived experience of Americans and their attitude towards racism and social and political inequality. Drawing on the studies of public attitude, the article points towards a persisting racism the postracial society aimed to overcome and to the effect recent Black activism had on dismantling the fantasy. The article shows how on the one hand, racism is grounded in the unconscious and in the way a subject becomes politicized, while on the other hand, racism already permeates political categories such as rights or citizenship, concluding that a Black subject cannot exist politically as a Black subject. There is always something that a Black subject has in the excess and that mis‐fits with White political categories. The article turns to Lacan's psychoanalysis and his ideas of identification to address the relationship between the subject and the form of authority. Further, the article draws on the postcolonial psychoanalytically inspired ideas of Franz Fanon and W. E. B. Du Bois to frame the relationship between the White master and the Black subject and to present the impossibility the Black subject faces when met with the implicitly racially biased White political categories.
Pathogenic variability of Plasmopara halstedii infecting sunflower in the Czech Republic
Authors: Drábková Trojanová Z. , Sedlářová M. , Pospíchalová R. , Lebeda A.
Published: May 2017

Plasmopara halstedii was isolated from diseased sunflowers collected from eight locations in the Czech Republic from 2007 to 2014. Races of the pathogen were determined based on 84 isolates collected during the study. In total, eight races of P. halstedii were detected using a set of nine sunflower differential lines. Races 700, 704, 705, 710, 714 and 715 were proven by soil drench inoculation, and two additional races (730 and 770) proposed by the previously applied leaf disc inoculation method. Race 700 was the most dominant in the Czech P. halstedii populations, with race 710 being the second most frequent. Races 704 and 714 were found over three seasons, while other races were recorded only in one growing season (race 730 in 2010, and the new races 705 and 715 in 2014). A comprehensive study was further conducted for isolates collected in 2013–14 using an extended differential set consisting of 15 sunflower lines. According to the latter methodology which marks races with five‐digit virulence codes, races 70060, 70471, 70571, 71060, 71461 and 71571 were recorded. The growing complexity of P. halstedii pathogenicity exhibited by the ability to infect higher numbers of differential genotypes and resulting in determination of the new pathogen races (virulence profiles) 70571, 71461 and 71571 is alarming. Although the limited number of isolates studied cannot characterize the entire pathogen diversity in the Czech Republic, the trend towards more diverse virulence in P. halstedii populations is clearly demonstrated by the new records of races 704, 705, 714 and 715, all capable of overcoming the resistance gene Pl6.
Vaccinia virus proteins A36 and F12/E2 show strong preferences for different kinesin light chain isoforms
Authors: Gao William N.D. , Carpentier David C.J. , Ewles Helen A. , Lee Stacey‐Ann , Smith Geoffrey L.
Published: May 2017

Vaccinia virus (VACV) utilizes microtubule‐mediated trafficking at several stages of its life cycle, of which virus egress is the most intensely studied. During egress VACV proteins A36, F12 and E2 are involved in kinesin‐1 interactions; however, the roles of these proteins remain poorly understood. A36 forms a direct link between virions and kinesin‐1, yet in its absence VACV egress still occurs on microtubules. During a co‐immunoprecipitation screen to seek an alternative link between virions and kinesin, A36 was found to bind isoform KLC1 rather than KLC2. The F12/E2 complex associates preferentially with the C‐terminal tail of KLC2, to a region that overlaps the binding site of cellular 14‐3‐3 proteins. F12/E2 displaces 14‐3‐3 from KLC and, unlike 14‐3‐3, does not require phosphorylation of KLC for its binding. The region determining the KLC1 specificity of A36 was mapped to the KLC N‐terminal heptad repeat region that is responsible for its association with kinesin heavy chain. Despite these differing binding properties F12/E2 can co‐operatively enhance A36 association with KLC, particularly when using a KLC1‐KLC2 chimaera that resembles several KLC1 spliceforms and can bind A36 and F12/E2 efficiently. This is the first example of a pathogen encoding multiple proteins that co‐operatively associate with kinesin‐1.
Regionalization of the stretch reflex in the human vastus medialis
Authors: Gallina Alessio , Blouin Jean‐Sébastien , Ivanova Tanya D. , Garland S. Jayne
Published: May 2017

Key points

Regionalization of the stretch reflex, i.e. the notion that the activation of 1a afferents from a muscle region influences only the activation of motor units in the same region, has been demonstrated previously in animals but not in humans.

Mechanical stretches applied to regions of vastus medialis as close as 10 mm apart resulted in recruitment of motor units localized topographically with respect to the location of the mechanical stretch.

Stretch reflexes are regionalized in the human vastus medialis.

The human spinal cord has the neuromuscular circuitry to preferentially activate motoneurones innervating muscle fibres located in different regions of the vastus medialis.

The localization of motor unit territories provides an anatomical basis to suggest that the CNS may have more independence in motor unit recruitment and control strategies than what was previously thought. In this study, we investigated whether the human spinal cord has the neuromuscular circuitry to independently activate motor units located in different regions of the vastus medialis. Mechanical taps were applied to multiple locations in the vastus medialis (VM) in nine healthy individuals. Regional responses within the muscle were observed using a grid of 5 × 13 surface EMG electrodes. The EMG amplitude was quantified for each channel, and a cluster of channels showing the largest activation was identified. The spatial location of the EMG response was quantified as the position of the channels in the cluster. In a subset of three participants, intramuscular recordings were performed simultaneously with the surface EMG recordings. Mechanical taps resulted in localized, discrete responses for each participant. The spatial location of the elicited responses was dependent on the location of the tap (P < 0.001). Recordings with intramuscular electrodes confirmed the regional activation of the VM for different tap locations. Selective stimulation of 1a afferents localized in a region of the VM results in reflex recruitment of motor units in the same region. These findings suggest that the human spinal cord has the neuromuscular circuitry to modulate spatially the motoneuronal output to vastus medialis regions, which is a neuroanatomical prerequisite for regional activation.
A General Friction Model of Discrete Interactions for Tendon Actuated Dexterous Manipulators
Authors: Gao Anzhu , Zou Yun , Wang Zhidong , Liu Hao
Published: May 2017

Continuum robots present the great dexterity and compliance as dexterous manipulators to accomplish complex positioning tasks in confined anatomy during minimally invasive surgery. Tendon actuation is one of the most popular approaches, which is to insert the tendon to eccentrically go through and interact with the flexible backbone to accomplish compliant bends. However, hysteresis of tip trajectory of tendon actuated dexterous manipulators (TA–DMs) has been observed during the loading and unloading procedure, which is mainly caused by the hindered friction at discrete interactions between the actuation tendon and conduits. This paper aims to propose a general friction model to describe the interactions and friction profile at the multiple discrete contact points for tendon actuated dexterous manipulators under the history-dependent tendon tension. The friction model was integrated into the beam theory to describe the hysteresis and loading history-dependent behavior by solving the profiles of tendon force, normal force, and friction force, as well as the deflection of the dexterous manipulator. Experiments were carried out to validate the effectiveness of the proposed friction model. Results indicate that the friction model can successfully describe the discrete interaction and predict the deflection of dexterous manipulator subject to the different tendon loading histories. Furthermore, the effects of discrete friction to the tendon force propagation and the loading history-dependent behavior are discussed.
Modeling and Dynamic Analysis of an Electrical Helmholtz Resonator for Active Control of Resonant Noise
Authors: Kim Sang-Myeong , Pereira Joao A. , Turra Antonio E. , Cho Jun-Ho
Published: May 2017

This paper describes a theoretical and experimental investigation into an electrical Helmholtz resonator (EHR): that is, an active noise control (ANC) loudspeaker used in conjunction with a microphone and a feedback controller for suppressing resonant noise in an acoustic cavity. The microphone is collocated with the loudspeaker and a band pass filter of second-order is used as the control filter inside the controller. The EHR is configured as such in order to suppress an acoustic mode that is within the volume velocity drive frequency range of the loudspeaker used. The concepts of impedance and passivity are used to develop the mathematical model as well as to study its dynamics. From these, it is theoretically shown that the EHR for single-mode suppression is an extremely low-impedance acoustic damping device that electrically realizes the pressure neutralization mechanism of a conventional Helmholtz resonator (HR). Experimental work is also presented, in which an EHR is constructed to suppress the Helmholtz mode of an acoustic cavity at about 40 Hz by more than 40 dB, to justify the mathematical model and also to verify the dynamic control mechanism.
Longitudinal Associations Between Sedentary Behavior of Adolescent Girls, Their Mothers, and Best Friends
Authors: Raudsepp Lennart , Riso Eva-Maria
Published: May 2017

Purpose:

The objective of this study was to examine the prospective relationship and changes in sedentary behavior between adolescent girls, their mothers and best friends over time.

Method:

The results are based on 122 girls aged 11–12 years at baseline measurement, their mothers and best friends who completed ecological momentary assessment diary for the assessment of sedentary behavior. All measurements were taken at 3 time points separated by one year. We used structural equation modeling to examine associations among sedentary behavior of adolescent girls, their mothers and best friends.

Results:

A linear growth model for adolescent girls’ and their best friends’ sedentary behavior fit the data well, revealing an overall significant increase in sedentary behavior across time. Initial levels of mothers’ and best friends’ sedentary behavior were positively related with sedentary behavior of adolescent girls. The changes of adolescent girls’ and best friends’ sedentary behavior across 3 years were positively related. Cross-lagged panel analysis demonstrated significant reciprocal effects between adolescent girls’ and best friends’ sedentary behavior. Mothers’ sedentary behavior at baseline predicted daughters’ sedentary behavior at 1-year follow-up and vice versa.

Conclusion:

From early to midadolescence, changes in adolescent girls’ sedentary behavior were associated with changes in best friends’ sedentary behavior. These findings suggest reciprocal associations between sedentary behavior of adolescent girls and their best friends.
Toward “Sport for all”: Jang Gwon and Sport Promotion by the Korean YMCA in the Japanese Occupation Era
Authors: Cho Moongi
Published: May 2017

This study examines the historical significance of Jang Gwon’s activities in the sport promotion carried out by Korea’s YMCA. At its birth, the Korean YMCA’s sport promotion was closely linked with the Korean nationalist movement under Japanese colonial rule, and this link was most evident around 1920, when Jang Gwon worked as a judo master. Citing the Sokol movement in Czechoslovakia, Jang Gwon took initiatives to enlighten Korean people’s consciousness and popularize sports, including judo and basketball, across the country through the Korean YMCA’s sport promotion. In particular, Jang Gwon introduced modern judo—formally known as Gangdogwan (Kodokan judo), initiated by Jigoro Kano—in Korea and took initiatives to establish the Korean Basketball Association and the Korean Basketball Referee Association. Through the Korean YMCA’s sport promotion, Jang Gwon motivated the Korean people to aspire to liberation and independence from Japanese colonial rule. Moreover, amid the prevailing social climate, in which physical activities were discouraged due to the influence of Neo-Confucianism, he provided a paradigm shift that called for “sport for all,” which enabled the modernization of sports and physical education in Korea.
A Qualitative Examination of Adolescent Girls’ Sport Participation in a Low-Income, Urban Environment
Authors: Wright E. Missy , Griffes Katie R. , Gould Daniel R.
Published: May 2017

Even though African American girls and/or girls in low-income, urban environments are specifically challenged with their sport involvement, little research has focused specifically on this population’s experience with sport. The purpose of this study was to examine various factors related to sport participation for adolescent girls (predominantly African American) living in a low-income urban environment. The study examined the barriers that might impede their sport involvement, the benefits they perceive, and the reasons why they do or do not participate. Four focus groups were conducted in Detroit, Michigan (a large urban Midwestern city). Participants were grouped by age, as well as sport participation status (current sort participants and girls who have not participated in organized sport for at least one year). Each group consisted of 4 girls. Results revealed various reasons why the participants engaged in sport, including that sport occupies their time and that it is fun, while reasons like lack of opportunities and the negative role of others were some of the reasons provided for not participating in sport. These girls face numerous barriers to sport participation, such as logistical, financial, and cosmetic. Positive psychosocial development and scholarships were noted as benefits to participation. Directions for future research and programmatic level applications are described in light of these findings.
Relationship Among Gender, Athletic Involvement, Student Organization Involvement and Leadership
Authors: Mak Jennifer Y. , Kim Chong
Published: May 2017

Leadership development is important for society, and participating in athletics and student organizations has provided opportunities for young adults to develop and display leadership qualities (Dobosz & Beaty, 1999; Knoppers, 2011; Todd & Kent, 2004; Williams, Roberts, & Bosselman, 2011). The empirical research examining the leadership development through athletics and student organizations involvement has, unfortunately, been limited. Thus, the purpose of this study was to identify and investigate the relationship among gender, athletic involvement, and student organization involvement in relation to transformational leadership skills. Stratified random sampling and the Salant and Dillman (1994) survey methodology procedure were adopted for data collection. Data were collected from 992 college students (493 females and 495 males) in a Mid-Atlantic university. The Transformational Leadership Scale (Hellriegel & Slocum, 2004) was used as the instrument to measure the variables. Descriptive statistics and factorial ANOVA were used for data analysis. Results showed significant differences existed among gender, athletic involvement, and student organization involvement in relation to transformational leadership skills. Females, athletes, and student officers received significantly higher scores than males, nonathletes and nonstudent officers in transformational leadership.
Papers of note in
Science
356
(6337)
Authors: VanHook Annalisa M.
Published: May 2017

This week’s articles address the role of macrophage metabolic reprogramming in resolving inflammation and an epidermal pattern formation system that is self-organizing and can adjust to fit the size of the tissue.
The Etest Performed Directly on Blood Culture Bottles Is a Reliable Tool for Detection of Fluconazole-Resistant Candida albicans Isolates
Authors: Escribano Pilar , Marcos-Zambrano Laura Judith , Gómez Ana , Sánchez Carlos , Martínez-Jiménez M. Carmen , Bouza Emilio , Guinea Jesús
Published: May 2017

We assessed the ability of the Etest performed directly on positive blood cultures (ET
DIR
) to detect fluconazole susceptibility in 6 fluconazole-resistant and 12 fluconazole-susceptible
Candida albicans
isolates, according to CLSI M27-A3 and EUCAST EDef 7.2 procedures. Categorical agreement between ET
DIR
and broth microdilution was 100% when the trays were incubated at 25°C and trailing effect was ruled out. ET
DIR
is a reliable procedure when screening for the presence of fluconazole resistance in
C. albicans
.
New Aspects of the Interplay between Penicillin Binding Proteins,
murM
, and the Two-Component System CiaRH of Penicillin-Resistant Streptococcus pneumoniae Serotype 19A Isolates from Hungary
Authors: Schweizer Inga , Blättner Sebastian , Maurer Patrick , Peters Katharina , Vollmer Daniela , Vollmer Waldemar , Hakenbeck Regine , Denapaite Dalia
Published: May 2017

The
Streptococcus pneumoniae
clone Hungary
19A
-6 expresses unusually high levels of β-lactam resistance, which is in part due to mutations in the MurM gene, encoding a transferase involved in the synthesis of branched peptidoglycan. Moreover, it contains the allele
ciaH232
, encoding the histidine kinase CiaH (M. Müller, P. Marx, R. Hakenbeck, and R. Brückner, Microbiology 157:3104–3112, 2011,
https://doi.org/10.1099/mic.0.053157-0
). High-level penicillin resistance primarily requires the presence of low-affinity (mosaic) penicillin binding protein (PBP) genes, as, for example, in strain Hu17, a closely related member of the Hungary
19A
-6 lineage. Interestingly, strain Hu15 is β-lactam sensitive due to the absence of mosaic PBPs. This unique situation prompted us to investigate the development of cefotaxime resistance in transformation experiments with genes known to play a role in this phenotype,
pbp2x
,
pbp1a
,
murM
, and
ciaH
, and penicillin-sensitive recipient strains R6 and Hu15. Characterization of phenotypes, peptidoglycan composition, and CiaR-mediated gene expression revealed several novel aspects of penicillin resistance. The
murM
gene of strain Hu17 (
murM
Hu17
), which is highly similar to
murM
of
Streptococcus mitis
, induced morphological changes which were partly reversed by
ciaH232. murM
Hu17
conferred cefotaxime resistance only in the presence of the
pbp2x o
f strain Hu17 (
pbp2x
Hu17
). The
ciaH232
allele contributed to a remarkable increase in cefotaxime resistance in combination with
pbp2x
Hu17
and
pbp1a
of strain Hu17 (
pbp1a
Hu17
), accompanied by higher levels of expression of CiaR-regulated genes, documenting that
ciaH232
responds to PBP1a
Hu17
-mediated changes in cell wall synthesis. Most importantly, the proportion of branched peptides relative to the proportion of linear muropeptides increased in cells containing mosaic PBPs, suggesting an altered enzymatic activity of these proteins.
Multicenter Study of Outcomes with Ceftazidime-Avibactam in Patients with Carbapenem-Resistant Enterobacteriaceae Infections
Authors: King Madeline , Heil Emily , Kuriakose Safia , Bias Tiffany , Huang Vanthida , El-Beyrouty Claudine , McCoy Dorothy , Hiles Jon , Richards Lynette , Gardner Julianne , Harrington Nicole , Biason Kenneth , Gallagher Jason C.
Published: May 2017

Ceftazidime-avibactam is a novel cephalosporin–beta-lactamase inhibitor combination that is active against many carbapenem-resistant
Enterobacteriaceae
(CRE). We describe a retrospective chart review for 60 patients who received ceftazidime-avibactam for a CRE infection. In-hospital mortality was 32%, 53% of patients had microbiological cure, and 65% had clinical success. In this severely ill population with CRE infections, ceftazidime-avibactam was an appropriate option.
Ceftolozane-Tazobactam Activity against Pseudomonas aeruginosa Clinical Isolates from U.S. Hospitals: Report from the PACTS Antimicrobial Surveillance Program, 2012 to 2015
Authors: Shortridge Dee , Castanheira Mariana , Pfaller Michael A. , Flamm Robert K.
Published: May 2017

The activity of ceftolozane-tazobactam was compared to the activities of 7 antimicrobials against 3,851
Pseudomonas aeruginosa
isolates collected from 32 U.S. hospitals in the Program to Assess Ceftolozane-Tazobactam Susceptibility from 2012 to 2015. Ceftolozane-tazobactam and comparator susceptibilities were determined using the CLSI broth microdilution method at a central monitoring laboratory. For ceftolozane-tazobactam, 97.0% of the isolates were susceptible. Susceptibilities of the other antibacterials tested were: amikacin, 96.9%; cefepime, 85.9%; ceftazidime, 85.1%; colistin, 99.2%; levofloxacin, 76.6%; meropenem, 81.8%; and piperacillin-tazobactam, 80.4%. Of the 699 (18.1%) meropenem-nonsusceptible
P. aeruginosa
isolates, 87.6% were susceptible to ceftolozane-tazobactam. Six hundred seven isolates (15.8%) were classified as multidrug resistant (MDR), and 363 (9.4%) were classified as extensively drug resistant (XDR). Only 1 isolate was considered pandrug resistant, which was resistant to all tested agents, including colistin. Of the 607 MDR isolates, 84.9% were ceftolozane-tazobactam susceptible, and 76.9% of XDR isolates were ceftolozane-tazobactam susceptible.
In vitro
activity against drug-resistant
P. aeruginosa
indicates ceftolozane-tazobactam may be an important agent in treating serious bacterial infections.
Toll-Like Receptor 2 and Mincle Cooperatively Sense Corynebacterial Cell Wall Glycolipids
Authors: Schick Judith , Etschel Philipp , Bailo Rebeca , Ott Lisa , Bhatt Apoorva , Lepenies Bernd , Kirschning Carsten , Burkovski Andreas , Lang Roland
Published: May 2017

NontoxigenicCorynebacterium diphtheriaeandCorynebacterium ulceranscause invasive disease in humans and animals. Host sensing of corynebacteria is largely uncharacterized, albeit the recognition of lipoglycans by Toll-like receptor 2 (TLR2) appears to be important for macrophage activation by corynebacteria. The members of the orderCorynebacterineae(e.g., mycobacteria, nocardia, and rhodococci) share a glycolipid-rich cell wall dominated by mycolic acids (termed corynomycolic acids in corynebacteria). The mycolic acid-containing cord factor of mycobacteria, trehalose dimycolate, activates the C-type lectin receptor (CLR) Mincle. Here, we show that glycolipid extracts from the cell walls of several pathogenic and nonpathogenicCorynebacteriumstrains directly bound to recombinant Minclein vitro. Macrophages deficient in Mincle or its adapter protein Fc receptor gamma chain (FcRγ) produced severely reduced amounts of granulocyte colony-stimulating factor (G-CSF) and of nitric oxide (NO) upon challenge with corynebacterial glycolipids. Consistently, cell wall extracts of a particularC. diphtheriaestrain (DSM43989) lacking mycolic acid esters neither bound Mincle nor activated macrophages. Furthermore, TLR2 but not TLR4 was critical for sensing of cell wall extracts and whole corynebacteria. The upregulation of Mincle expression upon encountering corynebacteria required TLR2. Thus, macrophage activation by the corynebacterial cell wall relies on TLR2-driven robust Mincle expression and the cooperative action of both receptors.
Association of Metal Homeostasis and (p)ppGpp Regulation in the Pathophysiology of Enterococcus faecalis
Authors: Colomer-Winter C. , Gaca A. O. , Lemos J. A.
Published: May 2017

In
Enterococcus faecalis
, the regulatory nucleotides pppGpp and ppGpp, collectively, (p)ppGpp, are required for growth in blood, survival within macrophages, and virulence. However, a clear understanding of how (p)ppGpp promotes virulence in
E. faecalis
and other bacterial pathogens is still lacking. In the host, the essential transition metals iron (Fe) and manganese (Mn) are not readily available to invading pathogens because of a host-driven process called nutritional immunity. Considering its central role in adaptation to nutritional stresses, we hypothesized that (p)ppGpp mediates
E. faecalis
virulence through regulation of metal homeostasis. Indeed, supplementation of serum with either Fe or Mn restored growth and survival of the Δ
rel
Δ
relQ
[(p)ppGpp
0
] strain to wild-type levels. Using a chemically defined medium, we found that (p)ppGpp accumulates in response to either Fe depletion or Mn depletion and that the (p)ppGpp
0
strain has a strong growth requirement for Mn that is alleviated by Fe supplementation. Although inactivation of the nutrient-sensing regulator
codY
restored some phenotypes of the (p)ppGpp
0
strain, transcriptional analysis showed that the (p)ppGpp/CodY network does not promote transcription of known metal transporters. Interestingly, physiologic and enzymatic investigations suggest that the (p)ppGpp
0
strain requires higher levels of Mn in order to cope with high levels of endogenously produced reactive oxygen species (ROS). Because (p)ppGpp mediates antibiotic persistence and virulence in several bacteria, our findings have broad implications and provide new leads for the development of novel therapeutic and preventive strategies against
E. faecalis
and beyond.
Quorum Sensing Gene Regulation by LuxR/HapR Master Regulators in Vibrios
Authors: Ball Alyssa S. , Chaparian Ryan R. , van Kessel Julia C.
Published: May 2017

The coordination of group behaviors in bacteria is accomplished via the cell-cell signaling process called quorum sensing. Vibrios have historically been models for studying bacterial communication due to the diverse and remarkable behaviors controlled by quorum sensing in these bacteria, including bioluminescence, type III and type VI secretion, biofilm formation, and motility. Here, we discuss the
Vibrio
LuxR/HapR family of proteins, the master global transcription factors that direct downstream gene expression in response to changes in cell density. These proteins are structurally similar to TetR transcription factors but exhibit distinct biochemical and genetic features from TetR that determine their regulatory influence on the quorum sensing gene network. We review here the gene groups regulated by LuxR/HapR and quorum sensing and explore the targets that are common and unique among
Vibrio
species.
The first reported case of Atypical Femoral Fracture caused by daily ibandronate prescribed for bone metastases in breast cancer
Authors: Espey Robert , Grimes Stephanie , Heyburn Gary , Kealey William David
Published: May 2017

A 55-year-old woman with bony metastatic breast cancer was commenced on daily ibandronic acid to prevent skeletal related events (SREs). Four years later, she began to experience new lower limb and groin pain with investigations leading to the suspicion of further metastatic spread to her left femur. While awaiting radiotherapy for this, she unfortunately tripped and fell sustaining a fracture to the proximal third of her left femur. Radiographic findings of her femur from both before and after the fall were suggestive of an atypical femoral fracture, presumed secondary to her bisphosphonate therapy rather than metastatic spread.
Toothpick impaction in a sigmoid diverticulum
Authors: Kumar Shanesh , Mehdipour Ramin , Arachchi Asiri , Cass Antony
Published: May 2017

A 70-year-old woman presented to our emergency department with recurrent episodes of left lower quadrant pain. She subsequently underwent high anterior resection with working diagnosis of acute diverticulitis, but intraoperatively was found to have perforated sigmoid diverticulum due to toothpick impaction. A high index of suspicion is required for diagnosis of toothpick ingestion. Appropriate preoperative investigations such as endoscopy and CT, despite their fairly low sensitivity, should be performed to increase the ability to accurately diagnose this condition and therefore optimise subsequent management.
Aripiprazole-induced hypersensitivity pneumonitis
Authors: Gunasekaran Kulothungan , Murthi Swetha , Jennings Jeffrey , Lone Nazir
Published: May 2017

Aripiprazole is an atypical antipsychotic agent commonly used in the management of schizophrenia. Aripiprazole has not been reported to have an association with interstitial lung disease. We describe a case of a 36-year-old woman who began to experience respiratory issues shortly after starting aripiprazole and presented to us 4 years later with progressive exertional shortness of breath. High-resolution CT of the chest showed a bilateral ground glass pattern. Video-assisted thoracoscopy with biopsy revealed alveolar septal thickening and an inflammatory infiltrate composed mainly of lymphocytes, suggestive of chronic hypersensitivity pneumonitis. After discontinuing aripiprazole and initiating prednisolone therapy, the patient’s pulmonary symptoms improved. This case highlights that aripiprazole can cause hypersensitivity pneumonitis in susceptible individuals.
Acute urinary retention and constipation precipitated by herpes zoster infection
Authors: MacCraith Eoin , Davis Niall F , Walsh Kilian
Published: May 2017

A 76-year-old man presented to the emergency department complaining of acute urinary retention (AUR) and severe constipation. His recent medical history included 4 days of treatment in the community for gluteal herpes zoster with famciclovir. A transurethral catheter was passed and the patient completed a full course of famciclovir with resolution of constipation. The patient’s catheter was successfully removed 3 weeks after his presentation. We report on the clinical presentation and management of an unusual case of AUR and constipation caused by a zoster viral infection of the S2–S4 dermatome.
Approach to investigation and treatment of persistent symptoms following sport-related concussion: a systematic review
Authors: Makdissi Michael , Schneider Kathryn J , Feddermann-Demont Nina , Guskiewicz Kevin M , Hinds Sidney , Leddy John J , McCrea Michael , Turner Michael , Johnston Karen M
Published: May 2017

Objective

To conduct a systematic review of the literature regarding assessment and treatment modalities in patients with persistent symptoms following sport-related concussion (SRC).

Data sources

We searched Medline, Embase, SPORTSDiscus, PsycINFO, CINAHL, Cochrane library and ProQuest Dissertation & Theses Global electronic databases.

Study eligibility criteria

Studies were included if they were original research, reported on SRC as the primary source of injury, included patients with persistent postconcussive symptoms (>10 days) and investigated the role of assessment or treatment modalities.

Results

Of 3225 articles identified in the preliminary search, 25 articles met the inclusion criteria. 11 articles were concerned with assessment and 14 articles with treatment of persistent symptoms following SRC. There were three randomised control trials and one quasi-experimental study. The remainder consisting of cross-sectional studies, historical cohorts and case series.

‘Persistent symptoms’ following SRC can be defined as clinical recovery that falls outside expected time frames (ie, >10–14 days in adults and >4 weeks in children). It does not reflect a single pathophysiological entity, but describes a constellation of non-specific post-traumatic symptoms that may be linked to coexisting and/or confounding pathologies. A detailed multimodal clinical assessment is required to identify specific primary and secondary processes, and treatment should target specific pathologies identified. There is preliminary evidence supporting the use of symptom-limited aerobic exercise, targeted physical therapy and a collaborative approach that includes cognitive behavioural therapy. Management of patients with persistent symptoms is challenging and should occur in a multidisciplinary collaborative setting, with healthcare providers with experience in SRC.