bluuebunny/crossref_metadata_2025_split huggingface dataset:
6-Gingerol reduces Pseudomonas aeruginosa biofilm formation and virulence via quorum sensing inhibition
Authors: Kim Han-Shin , Lee Sang-Hoon , Byun Youngjoo , Park Hee-Deung 
Published: March 2015

AbstractPseudomonas aeruginosa is a well-known pathogenic bacterium that forms biofilms and produces virulence factors via quorum sensing (QS). Interfering with normal QS interactions between signal molecules and their cognate receptors is a developing strategy for attenuating its virulence. Here we tested the hypothesis that 6-gingerol, a pungent oil of fresh ginger, reduces biofilm formation and virulence by antagonistically binding to P. aeruginosa QS receptors. In silico studies demonstrated molecular binding occurs between 6-gingerol and the QS receptor LasR through hydrogen bonding and hydrophobic interactions. Experimentally 6-gingerol reduced biofilm formation, several virulence factors (e.g., exoprotease, rhamnolipid and pyocyanin) and mice mortality. Further transcriptome analyses demonstrated that 6-gingerol successfully repressed QS-induced genes, specifically those related to the production of virulence factors. These results strongly support our hypothesis and offer insight into the molecular mechanism that caused QS gene repression.
Mirror neuron therapy for hemispatial neglect patients
Authors: Wang Wei , Zhang Xin , Ji Xiangtong , Ye Qian , Chen Wenli , Ni Jun , Shen Guangyu , Zhang Bing , Yuan Ti-Fei , Shan Chunlei 
Published: March 2015

AbstractMirror neuron system(MNS) based therapy has been employed to treat stroke induced movement disorders. However, its potential effects on patients with hemispatial neglect were uninvestigated. The present study set out to test the therapeutic efficiency of video watching of series of hand actions/movements (protocol A) in two patients with left hemispatial neglect, due to the right hemisphere stroke. The video containing dynamic landscape of natural scene or cities but not human/animals was used as the protocol B. The “ABA” training procedure for 3 weeks therefore allows us to internally control the individual differences. Before and after each week of training, the Chinese behavioral inattention test- Hongkong version (CBIT-HK) was implemented to evaluate the hemispatial neglect severity. Functional magnetic resonance imaging (fMRI) experiment was implemented in two health subjects to reveal the difference of brain activation between protocol A and B. The results showed that protocol A rather than protocol B significantly improved the CBIT-HK scores at first and third weeks, respectively. Protocol A induced more bilateral activations including right inferior parietal lobe (supramarginal gyrus), which belongs to MNS and is also critical region resulting to hemineglect. Conclusion: MNS activation can provide a novel therapy for hemispatial neglect patients.
Understanding the influence of all nodes in a network
Authors: Lawyer Glenn 
Published: March 2015

AbstractCentrality measures such as the degree, k-shell, or eigenvalue centrality can identify a network's most influential nodes, but are rarely usefully accurate in quantifying the spreading power of the vast majority of nodes which are not highly influential. The spreading power of all network nodes is better explained by considering, from a continuous-time epidemiological perspective, the distribution of the force of infection each node generates. The resulting metric, the expected force, accurately quantifies node spreading power under all primary epidemiological models across a wide range of archetypical human contact networks. When node power is low, influence is a function of neighbor degree. As power increases, a node's own degree becomes more important. The strength of this relationship is modulated by network structure, being more pronounced in narrow, dense networks typical of social networking and weakening in broader, looser association networks such as the Internet. The expected force can be computed independently for individual nodes, making it applicable for networks whose adjacency matrix is dynamic, not well specified, or overwhelmingly large.
Legacies of Past Exploitation and Climate affect Mammalian Sexes Differently on the Roof of the World - The Case of Wild Yaks
Authors: Berger Joel , Schaller George B. , Cheng Ellen , Kang Aili , Krebs Michael , Li Lishu , Hebblewhite Mark 
Published: March 2015

AbstractIn polar environments, a lack of empirical knowledge about biodiversity prompts reliance on species distribution models to predict future change, yet these ignore the role of biotic interactions including the role of long past human exploitation. To explore how mammals of extreme elevation respond to glacial recession and past harvest, we combined our fieldwork with remote sensing and used analyses of ~60 expeditions from 1850–1925 to represent baseline conditions for wildlife before heavy exploitation on the Tibetan Plateau. Focusing on endangered wild yaks (Bos mutus), we document female changes in habitat use across time whereupon they increasingly relied on steeper post-glacial terrain and currently have a 20x greater dependence on winter snow patches than males. Our twin findings—that the sexes of a cold-adapted species respond differently to modern climate forcing and long-past exploitation—indicate that effective conservation planning will require knowledge of the interplay between past and future if we will assure persistence of the region's biodiversity.
The study of surface states in a semi-infinite crystal
Authors: Wang Huiping , Gao Tingting , Tao Ruibao 
Published: March 2015

AbstractAn infinite three dimensional (3D) crystal can be constructed by an infinite number of parallel 2D (hkl) crystal planes (CPs) coupled to each other. Based on lattice model Hamiltonian with the hopping between the nearest neighbor (1NN) CPs and all possible neighbor hoppings within each CP, we analytically prove that a (hkl) cut crystal will not accommodate any surface states if the original infinite crystal has the reflection symmetry which results in the forward transfer matrix F to be equal to the backward one B, named as F-B dynamical symmetry. We also study the effect of the longer range couplings among the nNN (n > 1) CPs and surface relaxation on our conclusion and find that the small perturbation from both factors has no effect on our conclusion based on the perturbation theory. Thus our model may have the potential for studying surface states in some cut crystals with low-index surfaces. Our result may be helpful to visually predict which cutting direction in some non-topological crystals is unfavorable to generate surface states.
Transformation optics with Fabry-Pérot resonances
Authors: Sadeghi M. M. , Li Sucheng , Xu Lin , Hou Bo , Chen Huanyang 
Published: March 2015

AbstractTransformation optics is a powerful tool to design various novel devices, such as invisibility cloak. Fantastic effects from this technique are usually accompanied with singular mappings, resulting in challenging implementations and narrow bands of working frequencies. Here in this article, Fabry-Pérot resonances in materials of extreme anisotropy are used to design various transformation optical devices that are not only easy to realize but also work well for a set of resonant frequencies (multiple frequencies). As an example, a prototype of a cylindrical concentrator is fabricated for microwaves.
The Kato problem for operators with weighted ellipticity
Authors: Cruz-Uribe SFO David , Rios Cristian 
Published: March 2015

We consider second order operators

L

w

=
−

w

−
1

div
⁡

A

w

∇

\mathcal {L}_{w}=-w^{-1}\operatorname {div}\mathbf {A}_{w}\nabla

with ellipticity controlled by a Muckemphout

A

2

A_{2}

weight

w
w

. We prove that the Kato square root estimate

‖

L

w

1

/

2

f
‖

L

2

(
w
)

≈

‖
∇
f
‖

L

2

(
w
)

\left \Vert \mathcal {L} _{w}^{1/2}f\right \Vert _{L^{2}\left ( w\right ) }\approx \left \Vert \nabla f\right \Vert _{L^{2}\left ( w\right ) }

holds in the weighted space

L

2

(
w
)

L^{2}\left ( w\right )

.
Lethal congenital abnormalities: the importance of a multidisciplinary approach
Authors: Story Lisa , Kyle Pippa 
Published: March 2015

Abstract
Thanatophoric dysplasia is the most common lethal skeletal dysplasia complicating 1:20 000 pregnancies. It is characterized by a number of skeletal abnormalities including short long bones, bowing of the femur, short ribs and fingers, macrocephaly with frontal bossing, and a cloverleaf skull. In this case, with a history of consanguinity, these features were detected at the anomaly scan. When a serious abnormality is detected, regular review in a dedicated fetal medicine unit is essential to ensure that parents are adequately counseled on prognosis, and for further genetic testing or termination to be conducted if necessary. Parent’s opting to proceed with an affected pregnancy should be offered input from neonatologists with a clear plan for delivery and initial palliative management made. In the event of neonatal death, investigations including postmortem, skeletal survey, and DNA testing should be offered to confirm diagnosis and aid counselling of future pregnancies.
Pulmonary hypertension in pregnancy
Authors: Curry Ruth , Steer Philip , Swan Lorna 
Published: March 2015

Abstract
Pregnant women with pulmonary hypertension have a high risk of maternal and fetal morbidity and mortality. This case describes a pregnancy in a woman with a previously undiagnosed atrioventricular septal defect, a common atrioventricular valve and pulmonary hypertension. Benefitting from expert commentary from both a specialist obstetrician and a cardiologist, it highlights how the cardiovascular changes associated with pregnancy impact on pre-existing cardiac disease, as well as illustrating how best to clinically assess and manage women such as these in antenatal clinics using a multidisciplinary team. Despite an encouraging trend towards improved outcomes, the importance of contraceptive advice and pre-pregnancy counselling regarding risk is emphasized.
HIV in pregnancy: the dilemmas of management
Authors: Datta Shreelata , Toby Martina , Harding Kate , de Ruiter Annemiek 
Published: March 2015

Abstract
The prevalence of HIV in pregnant women in the UK has increased steadily over the past 20 years. This case describes pregnancy in a woman with known HIV infection and emphasizes the key clinical management strategies for such women. This includes minimizing the maternal viral load to reduce risk of maternal to child transmission, early recognition of HIV-related complications, and appropriate decisions regarding mode of delivery. This case benefits from a multidisciplinary approach with regard to drug management, and discussion with regard to complications (which may or may not be HIV-related), and postnatal support.
Maternal pyrexia: challenges in optimal perinatal management
Authors: Nanda Surabhi , Langford Kate , Marlow Neil 
Published: March 2015

Abstract
This case describes a case of prolonged rupture of fetal membranes at term, followed by induction of labour with prostaglandin and synthetic oxytocin (syntocinon), complicated by pyrexia in labour and postpartum genital tract sepsis. The accompanying text and figures allow readers to follow the progressive change in maternal observations, biochemical parameters, and fetal cardiotocograph which provide important clues as to the severity of the sepsis, which progresses rapidly after birth. Use of early warning systems, such as a MEOWS chart, to facilitate early detection of the deteriorating septic woman, together with early antibiotic therapy, microbiology liaison, and strong handover communication are emphasized.
Premature ovarian failure: not the same as the ‘normal’ menopause
Authors: Cartwright Beth , Rymer Janice 
Published: March 2015

Abstract
Premature ovarian failure, defined as loss of ovarian function before the age of 45, affects 1 in 20 women. Whilst the cause is often unknown, this case describes the investigation and clinical management of premature ovarian failure in a 29-year-old woman, caused by an FMR1 premutation. It emphasizes the physiological and psychological differences in managing women with premature ovarian failure when compared to the ‘normal’ menopause, and the vital importance of oestrogen replacement therapy.
Recent evolution inRattus norvegicusis shaped by declining effective population size
Authors: Deinum Eva E. , Halligan Daniel L. , Ness Rob W. , Zhang Yao-Hua , Cong Lin , Zhang Jian-Xu , Keightley Peter D. 
Published: March 2015

AbstractThe brown rat,Rattus norvegicus, is both a notorious pest and a frequently used model in biomedical research. By analysing genome sequences of 12 wild-caught brown rats from their ancestral range in NE China, along with the sequence of a black rat,R. rattus, we investigate the selective and demographic forces shaping variation in the genome. We estimate that the recent effective population size (Ne) of this species = 1.24 × 105, based on silent site diversity. We compare patterns of diversity in these genomes with patterns in multiple genome sequences of the house mouse (Mus musculus castaneus), which has a much largerNe. This reveals an important role for variation in the strength of genetic drift in mammalian genome evolution. By a Pairwise Sequentially Markovian Coalescent (PSMC) analysis of demographic history, we infer that there has been a recent population size bottleneck in wild rats, which we date to approximately 20,000 years ago. Consistent with this, wild rat populations have experienced an increased flux of mildly deleterious mutations, which segregate at higher frequencies in protein-coding genes and conserved noncoding elements (CNEs). This leads to negative estimates of the rate of adaptive evolution (α) in proteins and CNEs, a result which we discuss in relation to the strongly positive estimates observed in wild house mice. As a consequence of the population bottleneck, wild rats also show a markedly slower decay of linkage disequilibrium with physical distance than wild house mice.
Measuring β‐diversity with species abundance data
Authors: Barwell Louise J. , Isaac Nick J. B. , Kunin William E. 
Published: March 2015

Summary

In 2003, 24 presence–absence β‐diversity metrics were reviewed and a number of trade‐offs and redundancies identified. We present a parallel investigation into the performance of abundance‐based metrics of β‐diversity.

β‐diversity is a multi‐faceted concept, central to spatial ecology. There are multiple metrics available to quantify it: the choice of metric is an important decision.

We test 16 conceptual properties and two sampling properties of a β‐diversity metric: metrics should be 1) independent of α‐diversity and 2) cumulative along a gradient of species turnover. Similarity should be 3) probabilistic when assemblages are independently and identically distributed. Metrics should have 4) a minimum of zero and increase monotonically with the degree of 5) species turnover, 6) decoupling of species ranks and 7) evenness differences. However, complete species turnover should always generate greater values of β than extreme 8) rank shifts or 9) evenness differences. Metrics should 10) have a fixed upper limit, 11) symmetry (βA,B = βB,A), 12) double‐zero asymmetry for double absences and double presences and 13) not decrease in a series of nested assemblages. Additionally, metrics should be independent of 14) species replication 15) the units of abundance and 16) differences in total abundance between sampling units. When samples are used to infer β‐diversity, metrics should be 1) independent of sample sizes and 2) independent of unequal sample sizes. We test 29 metrics for these properties and five ‘personality’ properties.

Thirteen metrics were outperformed or equalled across all conceptual and sampling properties. Differences in sensitivity to species’ abundance lead to a performance trade‐off between sample size bias and the ability to detect turnover among rare species. In general, abundance‐based metrics are substantially less biased in the face of undersampling, although the presence–absence metric, βsim, performed well overall. Only βBaselga R turn, βBaselga B‐C turn and βsim measured purely species turnover and were independent of nestedness. Among the other metrics, sensitivity to nestedness varied >4‐fold.

Our results indicate large amounts of redundancy among existing β‐diversity metrics, whilst the estimation of unseen shared and unshared species is lacking and should be addressed in the design of new abundance‐based metrics.
Resources, key traits and the size of fungal epidemics in Daphnia populations
Authors: Civitello David J. , Penczykowski Rachel M. , Smith Aimee N. , Shocket Marta S. , Duffy Meghan A. , Hall Spencer R. 
Published: March 2015

Summary

Parasites can profoundly affect host populations and ecological communities. Thus, it remains critical to identify mechanisms that drive variation in epidemics. Resource availability can drive epidemics via traits of hosts and parasites that govern disease spread.

Here, we map resource–trait–epidemic connections to explain variation in fungal outbreaks (Metschnikowia bicuspidata) in a zooplankton host (Daphnia dentifera) among lakes. We predicted epidemics would grow larger in lakes with more phytoplankton via three energetic mechanisms. First, resources should stimulate Daphnia reproduction, potentially elevating host density. Secondly, resources should boost body size of hosts, enhancing exposure to environmentally distributed propagules through size‐dependent feeding. Thirdly, resources should fuel parasite reproduction within hosts.

To test these predictions, we sampled 12 natural epidemics and tracked edible algae, fungal infection prevalence, body size, fecundity and density of hosts, as well as within‐host parasite loads.

Epidemics grew larger in lakes with more algal resources. Structural equation modelling revealed that resource availability stimulated all three traits (host fecundity, host size and parasite load). However, only parasite load connected resources to epidemic size. Epidemics grew larger in more dense Daphnia populations, but host density was unrelated to host fecundity (thus breaking its link to resources).

Thus, via energetic mechanisms, resource availability can stimulate key trait(s) governing epidemics in nature. A synthetic focus on resources and resource–trait links could yield powerful insights into epidemics.
The Thermus thermophilus comEA/comEC operon is associated with DNA binding and regulation of the DNA translocator and type IV pili
Authors: Salzer Ralf , Kern Timo , Joos Friederike , Averhoff Beate 
Published: March 2015

SummaryNatural transformation systems and type IV pili are linked in many naturally competent bacteria. In the Gram‐negative bacterium Thermus thermophilus, a leading model organism for studies of DNA transporters in thermophilic bacteria, seven competence proteins play a dual role in both systems, whereas two competence genes, comEA and comEC, are suggested to represent unique DNA translocator proteins. Here we show that the T. thermophilus ComEA protein binds dsDNA and is anchored in the inner membrane. comEA is co‐transcribed with the flanking comEC gene, and transcription of this operon is upregulated by nutrient limitation and low temperature. To our surprise, a comEC mutant was impaired in piliation. We followed this observation and uncovered that the impaired piliation of the comEC mutant is due to a transcriptional downregulation of pilA4 and the pilN both playing a dual role in piliation and natural competence. Moreover, the comEC mutation resulted in a dramatic decrease in mRNA levels of the pseudopilin gene pilA1, which is unique for the DNA transporter. We conclude that ComEC modulates transcriptional regulation of type IV pili and DNA translocator components thereby mediating a response to extracellular parameters.
Functional distinctness in the exoproteomes of marine Synechococcus
Authors: Christie‐Oleza Joseph A. , Armengaud Jean , Guerin Philippe , Scanlan David J. 
Published: March 2015

SummaryThe exported protein fraction of an organism may reflect its life strategy and, ultimately, the way it is perceived by the outside world. Bioinformatic prediction of the exported pan‐proteome of Prochlorococcus and Synechococcus lineages demonstrated that (i) this fraction of the encoded proteome had a much higher incidence of lineage‐specific proteins than the cytosolic fraction (57% and 73% homologue incidence respectively) and (ii) exported proteins are largely uncharacterized to date (54%) compared with proteins from the cytosolic fraction (35%). This suggests that the genomic and functional diversity of these organisms lies largely in the diverse pool of novel functions these organisms export to/through their membranes playing a key role in community diversification, e.g. for niche partitioning or evading predation. Experimental exoproteome analysis of marine Synechococcus showed transport systems for inorganic nutrients, an interesting array of strain‐specific exoproteins involved in mutualistic or hostile interactions (i.e. hemolysins, pilins, adhesins), and exoenzymes with a potential mixotrophic goal (i.e. exoproteases and chitinases). We also show how these organisms can remodel their exoproteome, i.e. by increasing the repertoire of interaction proteins when grown in the presence of a heterotroph or decrease exposure to prey when grown in the dark. Finally, our data indicate that heterotrophic bacteria can feed on the exoproteome of Synechococcus.
Effects, but no interactions, of ubiquitous pesticide and parasite stressors on honey bee (Apis mellifera) lifespan and behaviour in a colony environment
Authors: Retschnig Gina , Williams Geoffrey R. , Odemer Richard , Boltin Janina , Di Poto Cornelia , Mehmann Marion M. , Retschnig Peter , Winiger Pius , Rosenkranz Peter , Neumann Peter 
Published: March 2015

SummaryInteractions between pesticides and parasites are believed to be responsible for increased mortality of honey bee (Apis mellifera) colonies in the northern hemisphere. Previous efforts have employed experimental approaches using small groups under laboratory conditions to investigate influence of these stressors on honey bee physiology and behaviour, although both the colony level and field conditions play a key role for eusocial honey bees. Here, we challenged honey bee workers under in vivo colony conditions with sublethal doses of the neonicotinoid thiacloprid, the miticide tau‐fluvalinate and the endoparasite Nosema ceranae, to investigate potential effects on longevity and behaviour using observation hives. In contrast to previous laboratory studies, our results do not suggest interactions among stressors, but rather lone effects of pesticides and the parasite on mortality and behaviour, respectively. These effects appear to be weak due to different outcomes at the two study sites, thereby suggesting that the role of thiacloprid, tau‐fluvalinate and N. ceranae and interactions among them may have been overemphasized. In the future, investigations into the effects of honey bee stressors should prioritize the use of colonies maintained under a variety of environmental conditions in order to obtain more biologically relevant data.