bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coherent dynamics in the rotor tip shear layer of utility-scale wind turbines
Authors: Yang Xiaolei , Hong Jiarong , Barone Matthew , Sotiropoulos Fotis 
Published: September 2016

Recent field experiments conducted in the near wake (up to 0.5 rotor diameters downwind of the rotor) of a Clipper Liberty C96 2.5 MW wind turbine using snow-based super-large-scale particle image velocimetry (SLPIV) (Hong et al., Nat. Commun., vol. 5, 2014, 4216) were successful in visualizing tip vortex cores as areas devoid of snowflakes. The so-visualized snow voids, however, suggested tip vortex cores of complex shape consisting of circular cores with distinct elongated comet-like tails. We employ large-eddy simulation (LES) to elucidate the structure and dynamics of the complex tip vortices identified experimentally. We show that the LES, with inflow conditions representing as closely as possible the state of the flow approaching the turbine when the SLPIV experiments were carried out, reproduce vortex cores in good qualitative agreement with the SLPIV results, essentially capturing all vortex core patterns observed in the field in the tip shear layer. The computed results show that the visualized vortex patterns are formed by the tip vortices and a second set of counter-rotating spiral vortices intertwined with the tip vortices. To probe the dependence of these newly uncovered coherent flow structures on turbine design, size and approach flow conditions, we carry out LES for three additional turbines: (i) the Scaled Wind Farm Technology (SWiFT) turbine developed by Sandia National Laboratories in Lubbock, TX, USA; (ii) the wind turbine developed for the European collaborative MEXICO (Model Experiments in Controlled Conditions) project; and (iii) the model turbine presented in the paper by Lignarolo et al. (J. Fluid Mech., vol. 781, 2015, pp. 467–493), and the Clipper turbine under varying inflow turbulence conditions. We show that similar counter-rotating vortex structures as those observed for the Clipper turbine are also observed for the SWiFT, MEXICO and model wind turbines. However, the strength of the counter-rotating vortices relative to that of the tip vortices from the model turbine is significantly weaker. We also show that incoming flows with low level turbulence attenuate the elongation of the tip and counter-rotating vortices. Sufficiently high turbulence levels in the incoming flow, on the other hand, tend to break up the coherence of spiral vortices in the near wake. To elucidate the physical mechanism that gives rise to such rich coherent dynamics we examine the stability of the turbine tip shear layer using the theory proposed by Leibovich & Stewartson (J. Fluid Mech., vol. 126, 1983, pp. 335–356). We show that for all simulated cases the theory consistently indicates the flow to be unstable exactly in the region where counter-rotating spirals emerge. We thus postulate that centrifugal instability of the rotating turbine tip shear layer is a possible mechanism for explaining the phenomena we have uncovered herein.
Transition to turbulence over 2D and 3D periodic large-scale roughnesses
Authors: Hamed A. M. , Sadowski M. , Zhang Z. , Chamorro L. P. 
Published: September 2016

A laboratory investigation was performed to study distinctive features of the laminar-to-turbulent transition over distributed roughness characterized by two-dimensional (2D) and three-dimensional (3D) periodic, low-order topographies at roughness Reynolds number $Re_{k}\approx 300$. Systematic experiments were performed using high-spatial-resolution planar particle image velocimetry (PIV) in a refractive-index-matching (RIM) channel, where the roughness covered the entire length of the test section. The results show that the flow over the 2D roughness becomes turbulent much sooner than its 3D counterpart ($Re_{x}=50\,000$ versus 120 000). This is attributed to the presence of a velocity inflection point resulting from flow separation within the troughs of the 2D roughness. In the transitional region, unsteady disturbances above the two roughnesses appear upstream of near-roughness disturbances. The above-roughness disturbances are associated with the inflection point in the vertically displaced boundary layer for the 2D case, and with the mean velocity deficit resulting from the interaction of the wakes of upstream elements for the 3D case. The near-roughness fluctuations are associated with the shear layer present behind the crests of both roughnesses. The transitional region is characterized by the interaction between above- and near-roughness disturbances, which merge, leading to a rapid vertical growth of the turbulent fluctuations.
The electrophoretic mobilities of a circular cylinder in close proximity to a dielectric wall
Authors: Yariv Ehud 
Published: September 2016

In their bipolar-coordinate analysis of circular-cylinder electrophoresis near a dielectric wall, Keh et al. (J. Fluid Mech., vol. 231, 1991, pp. 211–228) found that, when an electric field is applied parallel to the wall, the translational and rotational electrophoretic mobilities increase monotonically as the ratio $\unicode[STIX]{x1D6FF}$ of the cylinder–wall separation to the cylinder radius decreases, eventually diverging as $\unicode[STIX]{x1D6FF}^{-1/2}$ when $\unicode[STIX]{x1D6FF}\rightarrow 0$. Considering the singular limit $\unicode[STIX]{x1D6FF}\ll 1$ from the outset, we conduct here an asymptotic analysis of that electrokinetic problem, providing insight to the manner by which the intense electric field in the narrow gap is transformed into $O(\unicode[STIX]{x1D6FF}^{-3/2})$ shear stresses; these stresses, in turn, overcome the large Stokes resistance so as to provide the large electrophoretic mobilities. In a companion problem, where the cylinder is exposed to a uniform current emanating from a nearby reactive electrode, the intense gap-scale electric field results in an $O(\unicode[STIX]{x1D6FF}^{-2})$ pressure, giving rise in turn to a large repulsive force. In that problem we find that the cylinder velocity perpendicular to the wall approaches a finite limit as $\unicode[STIX]{x1D6FF}\rightarrow 0$. We also discuss the role of ‘dielectrophoretic’ forces which are inevitable in the above semi-bounded configurations.
“The Living, The Dead, The Undecided”: An Annotated Bibliography of Law Review Articles Dealing with the Law of Absentees and Returnees
Authors: Jarvis Robert M. , Chaney Megan F. 
Published: September 2016

AbstractOver the years, the legal problems posed by absentees and returnees have attracted the attention of scores of law review authors. Their work is difficult to access, however, because it is scattered across time and place. This is particularly problematic for a field that has no current organizing text. Accordingly, this bibliography collects and annotates the more notable pieces, dividing them into three principal categories: General Works, State-Specific Works, and Subject-Specific Works.
Crustal shortening at the Sierra Pie de Palo (Sierras Pampeanas, Argentina): near-surface basement folding and thrusting
Authors: BELLAHSEN N. , SEBRIER M. , SIAME L. 
Published: September 2016

AbstractThe Sierras Pampeanas consist of basement uplifts that are mainly controlled by W-verging crustal thrusts. One of these, the Sierra Pie de Palo, is controlled by a blind thrust whose kinematics is debated. We analysed the reverse faults located along the eastern side of the range and show that these are characterized by small displacements (few hundreds of metres) of the Neogene and Quaternary deposits controlled by the inherited basement metamorphic foliation and shear zones. At the sierra scale, the inherited foliation pattern appears already folded, before the Cenozoic shortening, forming a series of antiforms and synforms with various wavelengths. We propose that this structure is amplified during the Plio-Quaternary shortening, resulting in a large asymmetrical basement-cored anticline where foliation-parallel slip can act as folding mechanism. The overall kinematics is consistent with an E-verging fault-propagation fold; this proposed kinematics is an alternative to the frequently suggested W-verging fault-bend fold model. Finally, we propose a new, alternative and speculative crustal and lithospheric structure for this region consisting of two E-verging basement thrusts coeval to W-verging Pampean thrusts, both rooting below the Precordillera, above an eclogitized lower crust.
Cognitive remediation for individuals with psychosis: efficacy and mechanisms of treatment effects
Authors: Fiszdon J. M. , Choi K. H. , Bell M. D. , Choi J. , Silverstein S. M. 
Published: September 2016

BackgroundThe popularity of cognitive remediation (CR) interventions for individuals with psychosis is in part based on the well-established link between cognition and functioning and the assumption that by targeting cognition, function can improve. While numerous trials have reported CR's efficacy, it is still not considered an evidence-based treatment. Importantly, little is known about the mechanisms through which it may affect functioning.MethodIn this study, we evaluated CR's proximal and distal effects, and examined potential mechanisms. A total of 75 individuals with psychotic disorders were randomized to a combination of strategy-based and drill-and-practice CR or wait-list control, with assessments of training task performance, neurocognition, functional capacity, symptoms and functioning conducted at baseline, end of the 2-month intervention, and 2-month follow-up.ResultsCompared with treatment as usual, CR was associated with large post-training improvements on training tasks targeting attention, visuospatial memory, and verbal learning and memory, with persisting group differences at the 2-month follow-up. These generalized to mostly large improvements on neuropsychological measures targeting visuospatial memory, verbal learning and memory, delayed verbal memory and verbal working memory. While there were no CR-associated improvements on measures of functional capacity, symptoms, or a self-report measure of independent living skills, there was an effect on an interviewer-rated measure of functioning (Quality of Life Scale), which appeared primarily driven by the Intrapsychic Foundations subscale. Finally, for those randomized to CR, there were significant, medium-sized correlations between training task improvement, neuropsychological improvement and functioning measures.ConclusionsThis suggests a complex, multifactorial relationship between CR, and cognitive and functional change.
Two distinct patterns of treatment resistance: clinical predictors of treatment resistance in first-episode schizophrenia spectrum psychoses
Authors: Lally J. , Ajnakina O. , Di Forti M. , Trotta A. , Demjaha A. , Kolliakou A. , Mondelli V. , Reis Marques T. , Pariante C. , Dazzan P. , Shergil S. S. , Howes O. D. , David A. S. , MacCabe J. H. , Gaughran F. , Murray R. M. 
Published: September 2016

BackgroundClozapine remains the only evidence-based antipsychotic for treatment-resistant schizophrenia (TRS). The ability to predict which patients with their first onset of schizophrenia would subsequently meet criteria for treatment resistance (TR) could help to diminish the severe functional disability which may ensue if TR is not recognized and correctly treated.MethodThis is a 5-year longitudinal assessment of clinical outcomes in a cohort of 246 first-episode schizophrenia spectrum patients recruited as part of the NIHR Genetics and Psychosis (GAP) study conducted in South London from 2005 to 2010. We examined the relationship between baseline demographic and clinical measures and the emergence of TR. TR status was determined from a review of electronic case records. We assessed for associations with early-, and late-onset TR, and non-TR, and differences between those TR patients treated with clozapine and those who were not.ResultsSeventy per cent (n= 56) of TR patients, and 23% of the total study population (n= 246) were treatment resistant from illness onset. Those who met criteria for TR during the first 5 years of illness were more likely to have an early age of first contact for psychosis (<20 years) [odds ratio (OR) 2.49, 95% confidence interval (CI) 1.25–4.94] compared to those with non-TR. The relationship between an early age of first contact (<20 years) and TR was significant in patients of Black ethnicity (OR 3.71, 95% CI 1.44–9.56); and patients of male gender (OR 3.13 95% CI 1.35–7.23).ConclusionsFor the majority of the TR group, antipsychotic TR is present from illness onset, necessitating increased consideration for the earlier use of clozapine.
Gender and age group differences in suicide risk associated with co-morbid physical and psychiatric disorders in older adults
Authors: Vasiliadis Helen-Maria , Lamoureux-Lamarche Catherine , Gontijo Guerra Samantha 
Published: September 2016

ABSTRACTBackground:It is unclear whether health service use influences the association between psychiatric and physical co-morbidity and suicide risk in older adults.Methods:Controls were older adults (n= 2,494) participating in a longitudinal study on the health of the elderly carried out between 2004 and 2007, in Quebec. The cases were all suicide decedents (n= 493) between 2004 and 2007, confirmed by the Quebec Coroner's office. Multivariate analyses were carried out to test the association between suicide and the presence of psychiatric and physical illnesses controlling for health service use and socio-demographic factors by gender and age group. Interaction terms were also tested between suicide and co-morbidity on outpatient service use.Results:The presence of physical illnesses only, was associated with a reduced risk of suicide across all sex and age groups. The presence of a mental disorder only was associated with an increased risk of suicide overall and specifically in females and those aged 70 to 84 years of age. Suicide risk was lower in those with a psychiatric and physical co-morbidity and consulting mental health services.Conclusions:Increased mental health follow-up in older adults with psychiatric illnesses is needed for the detection of suicidal behavior and reducing suicide risk in males. Further research should focus on the mitigating effect of the presence of physical illnesses on stigma and health service use and the presence of social support in the elderly.
Adipose-derived mesenchymal stem cells promote the survival of fat grafts via crosstalk between the Nrf2 and TLR4 pathways
Authors: Chen Xiaosong , Yan Liu , Guo Zhihui , Chen Zhaohong , Chen Ying , Li Ming , Huang Chushan , Zhang Xiaoping , Chen Liangwan 
Published: September 2016

AbstractAutologous fat grafting is an effective reconstructive surgery technique; however, its success is limited by inconsistent graft retention and an environment characterized by high oxidative stress and inflammation. Adipose-derived stem cells (ADSCs) increase the survival of fat grafts, although the underlying mechanisms remain unclear. Here, TLR4−/− and Nrf2−/− mice were used to explore the effects of oxidative stress and inflammation on the viability and function of ADSCs in vitro and in vivo. Enrichment of fat grafts with ADSCs inhibited inflammatory cytokine production, enhanced growth factor levels, increased fat graft survival, downregulated NADPH oxidase (NOX)1 and 4 expression, increased vascularization and reduced ROS production in a manner dependent on toll-like receptor (TLR)-4 and nuclear factor erythroid 2-related factor 2 (Nrf2) expression. Immunohistochemical analysis showed that exposure to hypoxia enhanced ADSC growth and promoted the differentiation of ADSCs into vascular endothelial cells. Hypoxia-induced inflammatory cytokine, growth factor and NOX1/4 upregulation, as well as increased ROS production and apoptosis in ADSCs were dependent on TLR4 and Nrf2, which also modulated the effect of ADSCs on promoting endothelial progenitor cell migration and angiogenesis. Western blot analyses showed that the effects of hypoxia on ADSCs were regulated by crosstalk between Nrf2 antioxidant responses and NF-κB- and TLR4-mediated inflammatory responses. Taken together, our results indicate that ADSCs can increase the survival of fat transplants through the modulation of inflammatory and oxidative responses via Nrf2 and TLR4, suggesting potential strategies to improve the use of ADSCs for cell therapy.
Broad activation of latent HIV-1 in vivo
Authors: Barton Kirston , Hiener Bonnie , Winckelmann Anni , Rasmussen Thomas Aagaard , Shao Wei , Byth Karen , Lanfear Robert , Solomon Ajantha , McMahon James , Harrington Sean , Buzon Maria , Lichterfeld Mathias , Denton Paul W. , Olesen Rikke , Østergaard Lars , Tolstrup Martin , Lewin Sharon R. , Søgaard Ole Schmeltz , Palmer Sarah 
Published: September 2016

AbstractThe ‘shock and kill’ approach to cure human immunodeficiency virus (HIV) includes transcriptional induction of latent HIV-1 proviruses using latency-reversing agents (LRAs) with targeted immunotherapy to purge infected cells. The administration of LRAs (panobinostat or vorinostat) to HIV-1-infected individuals on antiretroviral therapy induces a significant increase in cell-associated unspliced (CA-US) HIV-1 RNA from CD4+ T cells. However, it is important to discern whether the increases in CA-US HIV-1 RNA are due to limited or broad activation of HIV-1 proviruses. Here we use single-genome sequencing to find that the RNA transcripts observed following LRA administration are genetically diverse, indicating activation of transcription from an extensive range of proviruses. Defective sequences are more frequently found in CA HIV-1 RNA than in HIV-1 DNA, which has implications for developing an accurate measure of HIV-1 reservoir size. Our findings provide insights into the effects of panobinostat and vorinostat as LRAs for latent HIV-1.
Characterization of a putative NsrR homologue in Streptomyces venezuelae reveals a new member of the Rrf2 superfamily
Authors: Munnoch John T. , Martinez Ma Teresa Pellicer , Svistunenko Dimitri A. , Crack Jason C. , Le Brun Nick E. , Hutchings Matthew I. 
Published: September 2016

AbstractMembers of the Rrf2 superfamily of transcription factors are widespread in bacteria but their functions are largely unexplored. The few that have been characterized in detail sense nitric oxide (NsrR), iron limitation (RirA), cysteine availability (CymR) and the iron sulfur (Fe-S) cluster status of the cell (IscR). In this study we combined ChIP- and dRNA-seq with in vitro biochemistry to characterize a putative NsrR homologue in Streptomyces venezuelae. ChIP-seq analysis revealed that rather than regulating the nitrosative stress response like Streptomyces coelicolor NsrR, Sven6563 binds to a conserved motif at a different, much larger set of genes with a diverse range of functions, including a number of regulators, genes required for glutamine synthesis, NADH/NAD(P)H metabolism, as well as general DNA/RNA and amino acid/protein turn over. Our biochemical experiments further show that Sven6563 has a [2Fe-2S] cluster and that the switch between oxidized and reduced cluster controls its DNA binding activity in vitro. To our knowledge, both the sensing domain and the putative target genes are novel for an Rrf2 protein, suggesting Sven6563 represents a new member of the Rrf2 superfamily. Given the redox sensitivity of its Fe-S cluster we have tentatively named the protein RsrR for Redox sensitive response Regulator.
Rapid conversions and avoided deforestation: examining four decades of industrial plantation expansion in Borneo
Authors: Gaveau David L. A. , Sheil Douglas , Husnayaen  , Salim Mohammad A. , Arjasakusuma Sanjiwana , Ancrenaz Marc , Pacheco Pablo , Meijaard Erik 
Published: September 2016

AbstractNew plantations can either cause deforestation by replacing natural forests or avoid this by using previously cleared areas. The extent of these two situations is contested in tropical biodiversity hotspots where objective data are limited. Here, we explore delays between deforestation and the establishment of industrial tree plantations on Borneo using satellite imagery. Between 1973 and 2015 an estimated 18.7 Mha of Borneo’s old-growth forest were cleared (14.4 Mha and 4.2 Mha in Indonesian and Malaysian Borneo). Industrial plantations expanded by 9.1 Mha (7.8 Mha oil-palm; 1.3 Mha pulpwood). Approximately 7.0 Mha of the total plantation area in 2015 (9.2 Mha) were old-growth forest in 1973, of which 4.5–4.8 Mha (24–26% of Borneo-wide deforestation) were planted within five years of forest clearance (3.7–3.9 Mha oil-palm; 0.8–0.9 Mha pulpwood). This rapid within-five-year conversion has been greater in Malaysia than in Indonesia (57–60% versus 15–16%). In Indonesia, a higher proportion of oil-palm plantations was developed on already cleared degraded lands (a legacy of recurrent forest fires). However, rapid conversion of Indonesian forests to industrial plantations has increased steeply since 2005. We conclude that plantation industries have been the principle driver of deforestation in Malaysian Borneo over the last four decades. In contrast, their role in deforestation in Indonesian Borneo was less marked, but has been growing recently. We note caveats in interpreting these results and highlight the need for greater accountability in plantation development.
Induction of hippocampal long-term potentiation increases the morphological dynamics of microglial processes and prolongs their contacts with dendritic spines
Authors: Pfeiffer Thomas , Avignone Elena , Nägerl U. Valentin 
Published: September 2016

AbstractRecently microglia, the resident immune cells of the brain, have been recognized as multi-tasking talents that are not only essential in the diseased brain, but also actively contribute to synaptic circuit remodeling during normal brain development. It is well established that microglia dynamically scan their environment and thereby establish transient physical contacts with neuronal synapses, which may allow them to sense and influence synaptic function. However, it is unknown whether and how the morphological dynamics of microglia and their physical interactions with synapses are affected by the induction of synaptic plasticity in the adult brain. To this end, we characterized the morphological dynamics of microglia and their interactions with synapses before and after the induction of synaptic plasticity (LTP) in the hippocampus by time-lapse two-photon imaging and electrophysiological recordings in acute brain slices. We demonstrate that during hippocampal LTP microglia alter their morphological dynamics by increasing the number of their processes and by prolonging their physical contacts with dendritic spines. These effects were absent in the presence of an NMDA receptor antagonist. Taken together, this altered behavior could reflect an active microglial involvement in circuit remodeling during activity-dependent synaptic plasticity in the healthy adult brain.