bluuebunny/crossref_metadata_2025 huggingface dataset:
Cu–Zn disorder and band gap fluctuations in Cu2ZnSn(S,Se)4: Theoretical and experimental investigations
Authors: Scragg Jonathan J. S. , Larsen Jes K. , Kumar Mukesh , Persson Clas , Sendler Jan , Siebentritt Susanne , Platzer Björkman Charlotte
Published: September 2015

Cu2ZnSn(S,Se)4 (CZTS(e)) solar cells suffer from low‐open‐circuit voltages that have been blamed on the existence of band gap fluctuations, with different possible origins. In this paper, we show from both theoretical and experimental standpoints that disorder of Cu and Zn atoms is in all probability the primary cause of these fluctuations. First, quantification of Cu–Zn disorder in CZTS thin films is presented. The results indicate that disorder is prevalent in the majority of practical samples used for solar cells. Then, ab initio calculations for different arrangements and densities of disorder‐induced [CuZn + ZnCu] defect pairs are presented and it is shown that spatial variations in band gap of the order of 200 meV can easily be caused by Cu–Zn disorder, which would cause large voltage losses in solar cells. Experiments using Raman spectroscopy and room temperature photoluminescence combined with in situ heat‐treatments show that a shift in the energy of the dominant band‐to‐band recombination pathway correlates perfectly to the order‐disorder transition, which clearly implicates Cu–Zn disorder as the cause of band gap fluctuations in CZTS. Our results suggest that elimination or passivation of Cu–Zn disorder could be very important for future improvements in the efficiency of CZTS(e)‐based solar cells.
Fracture of polycrystalline graphene membranes by in situ nanoindentation in a scanning electron microscope
Authors: Suk Ji Won , Mancevski Vladimir , Hao Yufeng , Liechti Kenneth M. , Ruoff Rodney S.
Published: September 2015

Failure of polycrystalline graphene grown by chemical vapor deposition was investigated by nanoindentation in a scanning electron microscope. Circular graphene membranes were subject to central point loads using a nanomanipulator combined with an atomic force microscope cantilever as a force sensor. The grain boundaries of the polycrystalline graphene were visualized by Raman spectroscopy coupled with a carbon isotope labeling technique. Graphene membranes without any grain boundary had a failure strength of 45.4 ± 10.4 GPa, compared to 16.4 ± 5.1 GPa for those with grain boundaries when a Young's modulus was assumed to be 1 TPa. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)
Observation‐based evaluation of ensemble reliability
Authors: Yamaguchi Munehiko , Lang Simon T. K. , Leutbecher Martin , Rodwell Mark J. , Radnoti Gabor , Bormann Niels
Published: September 2015

In order to obtain new insight into the reliability of the ensemble prediction system of the European Centre for Medium‐range Weather Forecasts (ECMWF), we compare the ensemble spread‐error relationship obtained from an observation‐based verification to the one obtained from an analysis‐based verification. Observations used in this study are mainly radiosonde temperatures and radiance measurements from the AMSU‐A channel 5 microwave temperature sounder. The observation operators from the 4D‐Var data assimilation scheme are used to map the forecasts into observation space. In ‘observation‐space’, observed radiances are compared with forecast radiances, derived from the ensemble's atmospheric profiles of temperature, gas concentrations, cloud, and surface properties using the ‘RTTOV’ radiative transfer code.

The observation‐space assessment yields different results than the analysis‐based assessment in the extratropics for short‐range forecasts (1‐day), and in the Tropics in general. In the extratropics, for 5‐day forecasts the discrepancy between the analysis‐based and observation‐based verification is small and the ensemble variances are quite reliable.

The observation‐based diagnostics indicate that the stochastic model error schemes contribute to the well‐tuned ensemble spread in the extratropics, but can degrade the reliability of the ensemble in the Tropics. It is suggested that observation‐based diagnostics should be used more routinely to diagnose the ensemble performance, and help diagnosing the effectiveness of model error schemes and estimating the amplitude of the initial perturbations.
Intermittent Urinary Catheterization: The Impact of Training on a Low-Fidelity Simulator on the Self-Confidence of Patients and Caregivers
Authors: Silva Dayane R. A. , Mazzo Alessandra , Jorge Beatriz M. , Souza Júnior Valtuir D. , Fumincelli Laís , Almeida Rodrigo G. S.
Published: September 2015

Purpose:

The purpose of this study was to identify how training on a low-fidelity simulator impacts the confidence of caregivers and patients with neurogenic bladder who use clean intermittent urinary catheterization.

Design:

Quasi-experimental study.

Methods:

Developed in a rehabilitation center in Brazil including patients who use clean intermittent urinary catheterization and caregivers from September to November 2013. After Ethics approval (Opinion 146/2012) during the nursing consultation, data were collected before and after training on a low-fidelity simulator.

Findings:

A total of 36 respondents (72.0%) patients and 14 (28.0%) caregivers participated. The self-confidence acquired after training on low-fidelity simulators was significant.

Conclusions:

In this study sample, low-fidelity simulation was demonstrated to be an effective strategy for the development of self-confidence.

Clinical Relevance:

Low-fidelity simulation training enables patients and caregivers to increase their self-confidence when performing clean intermittent urinary catheterization and should be used as a training strategy by healthcare professionals.
What is carbon? Conceptualising carbon and capabilities in the context of community sequestration projects in the global South
Authors: Twyman Chasca , Smith Thomas Aneurin , Arnall Alex
Published: September 2015

Carbon has been described as a ‘surreal commodity.’ While carbon trading, storage, sequestration, and emissions have become a part of the contemporary climate lexicon, how carbon is understood, valued, and interpreted by actors responsible for implementing carbon sequestration projects is still unclear. In this review paper, we are concerned with how carbon has come to take on a range of meanings. In particular, we appraise what is known about the situated meanings that people involved in delivering, and participating in, carbon sequestration projects in the global South assign to this complex element. There has been some reflection on the new meanings conferred on carbon via the neoliberal processes of marketisation and on how these processes interact with historical and contemporary narratives of environmental change. But less is known about how these meanings are (re)produced and (re)interpreted locally. We review how carbon has been defined both as a chemical element and as a tradable, marketable commodity. We discuss the implications these global meanings might have for situated understandings, particularly linked to climate change narratives, among communities in the global South. We consider how the concept of carbon capabilities, alongside theoretical notions of networks, assemblages, and local knowledges of the environment and nature, might be useful in beginning to understand how communities engage with abstract notions of carbon. We discuss the implications of specific values attributed to carbon, and therefore to different ecologies, for wider conceptualizations of how nature is valued, and climate is understood. We review in particular how this may impact on community interactions with carbon sequestration projects. Knowing more about how people understand, value, and know carbon allows policies to be better informed and practices more effectively targeted at engaging local populations meaningfully in carbon‐related projects. WIREs Clim Change 2015, 6:627–641. doi: 10.1002/wcc.367

This article is categorized under:

Climate and Development > Knowledge and Action in Development

Social Status of Climate Change Knowledge > Knowledge and Practice
The Hubble Constant
Authors: Jackson Neal
Published: September 2015

I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. There are two broad categories of measurements. The first uses individual astrophysical objects which have some property that allows their intrinsic luminosity or size to be determined, or allows the determination of their distance by geometric means. The second category comprises the use of all-sky cosmic microwave background, or correlations between large samples of galaxies, to determine information about the geometry of the Universe and hence the Hubble constant, typically in a combination with other cosmological parameters. Many, but not all, object-based measurements give H0 values of around 72–74 km s−1 Mpc−1, with typical errors of 2–3 km s−1 Mpc−1. This is in mild discrepancy with CMB-based measurements, in particular those from the Planck satellite, which give values of 67–68 km s−1 Mpc−1 and typical errors of 1–2 km s−1 Mpc−1. The size of the remaining systematics indicate that accuracy rather than precision is the remaining problem in a good determination of the Hubble constant. Whether a discrepancy exists, and whether new physics is needed to resolve it, depends on details of the systematics of the object-based methods, and also on the assumptions about other cosmological parameters and which datasets are combined in the case of the all-sky methods.
Is membrane homeostasis the missing link between inflammation and neurodegenerative diseases?
Authors: de Groot Natalia Sánchez , Burgas Marc Torrent
Published: September 2015

Systemic inflammation and infections are associated with neurodegenerative diseases. Unfortunately, the molecular bases of this link are still largely undiscovered. We, therefore, review how inflammatory processes can imbalance membrane homeostasis and theorize how this may have an effect on the aggregation behavior of the proteins implicated in such diseases. Specifically, we describe the processes that generate such imbalances at the molecular level, and try to understand how they affect protein folding and localization. Overall, current knowledge suggests that microglia pro-inflammatory mediators can generate membrane damage, which may have an impact in terms of triggering or accelerating disease manifestation.
68Ga-PSMA-11 PET/CT: a new technique with high potential for the radiotherapeutic management of prostate cancer patients
Authors: Sterzing Florian , Kratochwil Clemens , Fiedler Hannah , Katayama Sonja , Habl Gregor , Kopka Klaus , Afshar-Oromieh Ali , Debus Jürgen , Haberkorn Uwe , Giesel Frederik L.
Published: September 2015

Purpose

Radiotherapy is the main therapeutic approach besides surgery of localized prostate cancer. It relies on risk stratification and exact staging. This report analyses the potential of [68Ga]Glu-urea-Lys(Ahx)-HBED-CC (68Ga-PSMA-11), a new positron emission tomography (PET) tracer targeting prostate-specific membrane antigen (PSMA) for prostate cancer staging and individualized radiotherapy planning.

Methods

A cohort of 57 patients with prostate cancer scanned with 68Ga-PSMA-11 PET/CT for radiotherapy planning was retrospectively reviewed; 15 patients were at initial diagnosis and 42 patients at time of biochemical recurrence. Staging results of conventional imaging, including bone scintigraphy, CT or MRI, were compared with 68Ga-PSMA ligand PET/CT results and the influence on radiotherapeutic management was quantified.

Results

68Ga-PSMA ligand PET/CT had a dramatic impact on radiotherapy application in the presented cohort. In 50.8 % of the cases therapy was changed.

Conclusion

The presented imaging technique of 68Ga-PSMA PET/CT could be a key technology for individualized radiotherapy management in prostate cancer.
Heart valve tissue engineering: how far is the bedside from the bench?
Authors: Sanz-Garcia Andres , Oliver-de-la-Cruz Jorge , Mirabet Vicente , Gandía Carolina , Villagrasa Alejandro , Sodupe Enrique , Escobedo-Lucea Carmen
Published: September 2015

Heart disease, including valve pathologies, is the leading cause of death worldwide. Despite the progress made thanks to improving transplantation techniques, a perfect valve substitute has not yet been developed: once a diseased valve is replaced with current technologies, the newly implanted valve still needs to be changed some time in the future. This situation is particularly dramatic in the case of children and young adults, because of the necessity of valve growth during the patient's life. Our review focuses on the current status of heart valve (HV) therapy and the challenges that must be solved in the development of new approaches based on tissue engineering. Scientists and physicians have proposed tissue-engineered heart valves (TEHVs) as the most promising solution for HV replacement, especially given that they can help to avoid thrombosis, structural deterioration and xenoinfections. Lastly, TEHVs might also serve as a model for studying human valve development and pathologies.
Successful bone-anchored hearing aid implantation in a patient with osteogenesis imperfecta
Authors: Coutinho M B , Marques C , Mendes G J , Gonçalves C
Published: September 2015

Objective:

To report a case of successful bone-anchored hearing aid implantation in an adult patient with type III osteogenesis imperfecta, which is commonly regarded as a contraindication to this procedure.

Case report:

A 45-year-old man with type III osteogenesis imperfecta presented with mixed hearing loss. There was a mild sensorineural component in both ears, with an air–bone gap between 45 and 50 dB HL. He was implanted with a bone-anchored hearing aid. The audiological outcome was good, with no complications and good implant stability (as measured by resonance frequency analysis).

Conclusion:

To our knowledge, this is the first recorded case of bone-anchored hearing aid implantation in a patient with osteogenesis imperfecta.
FROMMYTHOSTOLOGOS: JEAN-PIERRE VERNANT, MAX WEBER, AND THE NARRATIVE OF OCCIDENTAL RATIONALIZATION
Authors: YU KENNETH W.
Published: September 2015

This article begins with a remark by Jean-Pierre Vernant in his inaugural lecture at the Collège de France about the inadequacy of Max Weber's historical sociology for the study of ancient religions. Despite posing shared research questions and often reaching similar conclusions, Vernant, one of the most influential twentieth-century ancient historians, neither engaged nor acknowledged Weber and thereby secured his absence in the field of ancient religions generally. Vernant's narrative of the historical emergence of Greek rationality is at direct odds with Weber's views on the matter inSociology of Religionand elsewhere, and I argue that, beyond methodological concerns, Vernant's fundamentally Durkheimian position inherits early twentieth-century polemics between French and German sociologists. Vernant's relationships with Marcel Mauss, Ignace Meyerson, and Claude Lévi-Strauss, and his participation in the French Resistance, moreover, reaffirmed his Durkheimian views about society and committed him to a long tradition of anti-German scholarship. I conclude with a brief coda on the historiographical implications of these observations for the study of religion and its relation to social life.
When The “Why” Makes You Socially Useful
Authors: Mange Jessica , Sénémeaud Cécile , Somat Alain
Published: September 2015

Abstract. This research investigates whether higher-level act identities, which indicate why one is performing a given action or the effects it will have, is more socially valued than lower-level act identities, which indicate how one performs the action. We investigated this question using three complementary paradigms involving self-presentation (Study 1, N = 39), identification (Study 2, N = 79), and a judge (Study 3, N = 63), respectively. Overall, we found that higher-level act identities met with greater social approval. In Studies 2 and 3, we found that higher-level act identities were valued because of their social utility and not associated with social desirability. We discuss the benefits of using a normative approach for understanding action identification processes and the effect of social pressure on endorsements of higher-level act identities.
To Include, or Not to Include?
Authors: Frauendorfer Denise , Schmid Mast Marianne , Sutter Corinne
Published: September 2015

Abstract. We investigated whether including an applicant’s photograph on a resume boosts or hampers the accurate assessment of that person’s (Big Five) personality traits and intelligence. A group of 114 participants rated 8 applicants (4 men and 4 women) with respect to their personality traits and intelligence. We used a 3 × 2 (Condition [resume with photograph, resume without photograph, photograph only] × Sex [male, female]) between-subjects design. In all conditions, all personality traits (except Agreeableness) were assessed at better than guessing level. Including a photograph on the resume did not significantly alter the accuracy of personality assessment.
Comprehensive multi-modality assessment of regional and global arterial structure and function in adults born preterm
Authors: Boardman Henry , Birse Katherine , Davis Esther F , Whitworth Polly , Aggarwal Veena , Lewandowski Adam J , Leeson Paul
Published: September 2015

Preterm birth is associated with higher blood pressure, which could be because preterm birth alters early aortic elastin and collagen development to cause increased arterial stiffness. We measured central and conduit artery size and multiple indices of arterial stiffness to define the extent and severity of macrovascular changes in individuals born preterm. A total of 102 young adults born preterm and 102 controls who were born after an uncomplicated pregnancy underwent cardiovascular magnetic resonance on a Siemens 1.5 T scanner to measure the aortic cross-sectional area in multiple locations. Ultrasound imaging with a Philips CX50 and linear array probe was used to measure carotid and brachial artery diameters. Carotid-femoral pulse wave velocity and the augmentation index were measured by SphygmoCor, brachial-femoral pulse wave velocity by Vicorder and aortic pulse wave velocity by cardiovascular magnetic resonance. The cardio-ankle vascular index (CAVI) was used as a measurement of global stiffness, and ultrasound was used to assess peripheral vessel distensibility. Adults born preterm had 20% smaller thoracic and abdominal aortic lumens (2.19±0.44 vs. 2.69±0.60 cm2, P<0.001; 1.25±0.36 vs. 1.94±0.45 cm2, P<0.001, respectively) but similar carotid and brachial diameters to adults born at term. Pulse wave velocity was increased (5.82±0.80 vs. 5.47±0.59 m s−1, P<0.01, 9.06±1.25 vs. 8.33±1.28 m s−1, P=0.01, 5.23±1.19 vs. 4.75±0.91 m s−1, P<0.01) and carotid distensibility was decreased (4.75±1.31 vs. 5.60±1.48 mm Hg−1103, P<0.001) in this group compared with the group born at term. However, the global and peripheral arterial stiffness measured by CAVI and brachial ultrasound did not differ (5.95±0.72 vs. 5.98±0.60, P=0.80 and 1.07±0.48 vs. 1.19±0.54 mm Hg−1103, P=0.12, respectively). Adults who are born preterm have significant differences in their aortic structure from adults born at term, but they have relatively small differences in central arterial stiffness that may be partially explained by blood pressure variations.
Wnt signalling tunes neurotransmitter release by directly targeting Synaptotagmin-1
Authors: Ciani Lorenza , Marzo Aude , Boyle Kieran , Stamatakou Eleanna , Lopes Douglas M. , Anane Derek , McLeod Faye , Rosso Silvana B. , Gibb Alasdair , Salinas Patricia C.
Published: September 2015

The functional assembly of the synaptic release machinery is well understood; however, how signalling factors modulate this process remains unknown. Recent studies suggest that Wnts play a role in presynaptic function. To examine the mechanisms involved, we investigated the interaction of release machinery proteins with Dishevelled-1 (Dvl1), a scaffold protein that determines the cellular locale of Wnt action. Here we show that Dvl1 directly interacts with Synaptotagmin-1 (Syt-1) and indirectly with the SNARE proteins SNAP25 and Syntaxin (Stx-1). Importantly, the interaction of Dvl1 with Syt-1, which is regulated by Wnts, modulates neurotransmitter release. Moreover, presynaptic terminals from Wnt signalling-deficient mice exhibit reduced release probability and are unable to sustain high-frequency release. Consistently, the readily releasable pool size and formation of SNARE complexes are reduced. Our studies demonstrate that Wnt signalling tunes neurotransmitter release and identify Syt-1 as a target for modulation by secreted signalling proteins.
Ultra-low-power hybrid light–matter solitons
Authors: Walker P. M. , Tinkler L. , Skryabin D. V. , Yulin A. , Royall B. , Farrer I. , Ritchie D. A. , Skolnick M. S. , Krizhanovskii D. N.
Published: September 2015

New functionalities in nonlinear optics will require systems with giant optical nonlinearity as well as compatibility with photonic circuit fabrication techniques. Here we introduce a platform based on strong light–matter coupling between waveguide photons and quantum-well excitons. On a sub-millimetre length scale we generate picosecond bright temporal solitons at a pulse energy of only 0.5 pJ. From this we deduce a nonlinear refractive index three orders of magnitude larger than in any other ultrafast system. We study both temporal and spatio-temporal nonlinear effects and observe dark–bright spatio-temporal polariton solitons. Theoretical modelling of soliton formation in the strongly coupled system confirms the experimental observations. These results show the promise of our system as a high speed, low power, integrated platform for physics and devices based on strong interactions between photons.
PTEN regulates cilia through Dishevelled
Authors: Shnitsar Iryna , Bashkurov Mikhail , Masson Glenn R. , Ogunjimi Abiodun A. , Mosessian Sherly , Cabeza Eduardo Aguiar , Hirsch Calley L. , Trcka Daniel , Gish Gerald , Jiao Jing , Wu Hong , Winklbauer Rudolf , Williams Roger L. , Pelletier Laurence , Wrana Jeffrey L. , Barrios-Rodiles Miriam
Published: September 2015

Cilia are hair-like cellular protrusions important in many aspects of eukaryotic biology. For instance, motile cilia enable fluid movement over epithelial surfaces, while primary (sensory) cilia play roles in cellular signalling. The molecular events underlying cilia dynamics, and particularly their disassembly, are not well understood. Phosphatase and tensin homologue (PTEN) is an extensively studied tumour suppressor, thought to primarily act by antagonizing PI3-kinase signalling. Here we demonstrate that PTEN plays an important role in multicilia formation and cilia disassembly by controlling the phosphorylation of Dishevelled (DVL), another ciliogenesis regulator. DVL is a central component of WNT signalling that plays a role during convergent extension movements, which we show here are also regulated by PTEN. Our studies identify a novel protein substrate for PTEN that couples PTEN to regulation of cilia dynamics and WNT signalling, thus advancing our understanding of potential underlying molecular etiologies of PTEN-related pathologies.
STIM1 dimers undergo unimolecular coupling to activate Orai1 channels
Authors: Zhou Yandong , Wang Xizhuo , Wang Xianming , Loktionova Natalia A. , Cai Xiangyu , Nwokonko Robert M. , Vrana Erin , Wang Youjun , Rothberg Brad S. , Gill Donald L.
Published: September 2015

The endoplasmic reticulum (ER) Ca2+ sensor, STIM1, becomes activated when ER-stored Ca2+ is depleted and translocates into ER–plasma membrane junctions where it tethers and activates Orai1 Ca2+ entry channels. The dimeric STIM1 protein contains a small STIM-Orai-activating region (SOAR)—the minimal sequence sufficient to activate Orai1 channels. Since SOAR itself is a dimer, we constructed SOAR concatemer–dimers and introduced mutations at F394, which is critical for Orai1 coupling and activation. The F394H mutation in both SOAR monomers completely blocks dimer function, but F394H introduced in only one of the dimeric SOAR monomers has no effect on Orai1 binding or activation. This reveals an unexpected unimolecular coupling between STIM1 and Orai1 and argues against recent evidence suggesting dimeric interaction between STIM1 and two adjacent Orai1 channel subunits. The model predicts that STIM1 dimers may be involved in crosslinking between Orai1 channels with implications for the kinetics and localization of Orai1 channel opening.
Trophic network architecture of root-associated bacterial communities determines pathogen invasion and plant health
Authors: Wei Zhong , Yang Tianjie , Friman Ville-Petri , Xu Yangchun , Shen Qirong , Jousset Alexandre
Published: September 2015

Host-associated bacterial communities can function as an important line of defence against pathogens in animals and plants. Empirical evidence and theoretical predictions suggest that species-rich communities are more resistant to pathogen invasions. Yet, the underlying mechanisms are unclear. Here, we experimentally test how the underlying resource competition networks of resident bacterial communities affect invasion resistance to the plant pathogen Ralstonia solanacearum in microcosms and in tomato plant rhizosphere. We find that bipartite resource competition networks are better predictors of invasion resistance compared with resident community diversity. Specifically, communities with a combination of stabilizing configurations (low nestedness and high connectance), and a clear niche overlap with the pathogen, reduce pathogen invasion success, constrain pathogen growth within invaded communities and have lower levels of diseased plants in greenhouse experiments. Bacterial resource competition network characteristics can thus be important in explaining positive diversity–invasion resistance relationships in bacterial rhizosphere communities.
High damage tolerance of electrochemically lithiated silicon
Authors: Wang Xueju , Fan Feifei , Wang Jiangwei , Wang Haoran , Tao Siyu , Yang Avery , Liu Yang , Beng Chew Huck , Mao Scott X. , Zhu Ting , Xia Shuman
Published: September 2015

Mechanical degradation and resultant capacity fade in high-capacity electrode materials critically hinder their use in high-performance rechargeable batteries. Despite tremendous efforts devoted to the study of the electro–chemo–mechanical behaviours of high-capacity electrode materials, their fracture properties and mechanisms remain largely unknown. Here we report a nanomechanical study on the damage tolerance of electrochemically lithiated silicon. Our in situ transmission electron microscopy experiments reveal a striking contrast of brittle fracture in pristine silicon versus ductile tensile deformation in fully lithiated silicon. Quantitative fracture toughness measurements by nanoindentation show a rapid brittle-to-ductile transition of fracture as the lithium-to-silicon molar ratio is increased to above 1.5. Molecular dynamics simulations elucidate the mechanistic underpinnings of the brittle-to-ductile transition governed by atomic bonding and lithiation-induced toughening. Our results reveal the high damage tolerance in amorphous lithium-rich silicon alloys and have important implications for the development of durable rechargeable batteries.
Climate constrains the evolutionary history and biodiversity of crocodylians
Authors: Mannion Philip D. , Benson Roger B. J. , Carrano Matthew T. , Tennant Jonathan P. , Judd Jack , Butler Richard J.
Published: September 2015

The fossil record of crocodylians and their relatives (pseudosuchians) reveals a rich evolutionary history, prompting questions about causes of long-term decline to their present-day low biodiversity. We analyse climatic drivers of subsampled pseudosuchian biodiversity over their 250 million year history, using a comprehensive new data set. Biodiversity and environmental changes correlate strongly, with long-term decline of terrestrial taxa driven by decreasing temperatures in northern temperate regions, and biodiversity decreases at lower latitudes matching patterns of increasing aridification. However, there is no relationship between temperature and biodiversity for marine pseudosuchians, with sea-level change and post-extinction opportunism demonstrated to be more important drivers. A ‘modern-type’ latitudinal biodiversity gradient might have existed throughout pseudosuchian history, and range expansion towards the poles occurred during warm intervals. Although their fossil record suggests that current global warming might promote long-term increases in crocodylian biodiversity and geographic range, the 'balancing forces' of anthropogenic environmental degradation complicate future predictions.
O-GlcNAcylation of G6PD promotes the pentose phosphate pathway and tumor growth
Authors: Rao Xiongjian , Duan Xiaotao , Mao Weimin , Li Xuexia , Li Zhonghua , Li Qian , Zheng Zhiguo , Xu Haimiao , Chen Min , Wang Peng G. , Wang Yingjie , Shen Binghui , Yi Wen
Published: September 2015

The pentose phosphate pathway (PPP) plays a critical role in macromolecule biosynthesis and maintaining cellular redox homoeostasis in rapidly proliferating cells. Upregulation of the PPP has been shown in several types of cancer. However, how the PPP is regulated to confer a selective growth advantage on cancer cells is not well understood. Here we show that glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme of the PPP, is dynamically modified with an O-linked β-N-acetylglucosamine sugar in response to hypoxia. Glycosylation activates G6PD activity and increases glucose flux through the PPP, thereby providing precursors for nucleotide and lipid biosynthesis, and reducing equivalents for antioxidant defense. Blocking glycosylation of G6PD reduces cancer cell proliferation in vitro and impairs tumor growth in vivo. Importantly, G6PD glycosylation is increased in human lung cancers. Our findings reveal a mechanistic understanding of how O-glycosylation directly regulates the PPP to confer a selective growth advantage to tumours.
Acute DNA damage activates the tumour suppressor p53 to promote radiation-induced lymphoma
Authors: Lee Chang-Lung , Castle Katherine D. , Moding Everett J. , Blum Jordan M. , Williams Nerissa , Luo Lixia , Ma Yan , Borst Luke B. , Kim Yongbaek , Kirsch David G.
Published: September 2015

Genotoxic cancer therapies, such as chemoradiation, cause haematological toxicity primarily by activating the tumour suppressor p53. While inhibiting p53-mediated cell death during cancer therapy ameliorates haematologic toxicity, whether it also impacts carcinogenesis remains unclear. Here we utilize a mouse model of inducible p53 short hairpin RNA (shRNA) to show that temporarily blocking p53 during total-body irradiation (TBI) not only ameliorates acute toxicity, but also improves long-term survival by preventing lymphoma development. Using KrasLA1 mice, we show that TBI promotes the expansion of a rare population of thymocytes that express oncogenic KrasG12D. However, blocking p53 during TBI significantly suppresses the expansion of KrasG12D-expressing thymocytes. Mechanistically, bone marrow transplant experiments demonstrate that TBI activates p53 to decrease the ability of bone marrow cells to suppress lymphoma development through a non-cell-autonomous mechanism. Together, our results demonstrate that the p53 response to acute DNA damage promotes the development of radiation-induced lymphoma.
Urbanization in China drives soil acidification of Pinus massoniana forests
Authors: Huang Juan , Zhang Wei , Mo Jiangming , Wang Shizhong , Liu Juxiu , Chen Hao
Published: September 2015

Soil acidification instead of alkalization has become a new environmental issue caused by urbanization. However, it remains unclear the characters and main contributors of this acidification. We investigated the effects of an urbanization gradient on soil acidity of Pinus massoniana forests in Pearl River Delta, South China. The soil pH of pine forests at 20-cm depth had significantly positive linear correlations with the distance from the urban core of Guangzhou. Soil pH reduced by 0.44 unit at the 0–10 cm layer in urbanized areas compared to that in non-urbanized areas. Nitrogen deposition, mean annual temperature and mean annual precipitation were key factors influencing soil acidification based on a principal component analysis. Nitrogen deposition showed significant linear relationships with soil pH at the 0–10 cm (for ammonium N ("Equation missing"-N), P < 0.05; for nitrate N ("Equation missing"-N), P < 0.01) and 10–20 cm (for "Equation missing"-N, P < 0.05) layers. However, there was no significant loss of exchangeable non-acidic cations along the urbanization gradient, instead their levels were higher in urban than in urban/suburban area at the 0–10 cm layer. Our results suggested N deposition particularly under the climate of high temperature and rainfall, greatly contributed to a significant soil acidification occurred in the urbanized environment.
Associations between interleukin and interleukin receptor gene polymorphisms and risk of gout
Authors: Liu Shiguo , Zhou Zheng , Wang Can , Guo Mingzhen , Chu Nan , Li Changgui
Published: September 2015

Gout is a self-limiting, auto-inflammatory arthritis induced by the deposition of monosodium urate crystals in the synovial fluid and periarticular tissues. The aim of this study was to investigate the associations between genetic variants in the interleukin (IL) and interleukin receptor (ILR) genes IL-33, IL-1RL1, IL-23R and signal transducer and activator of transcription 4 (STAT4) and susceptibility to gout in Chinese Han male individuals. The genetic distributions of rs3939286 in IL-33, rs13015714 in IL-1RL1, rs10889677 in IL-23R and rs7574865 in STAT4 were detected in 1100 men with gout and 1227 ethnically matched controls, using Taqman allelic discrimination real-time polymerase chain reaction (PCR). Differences in these polymorphisms between the groups were investigated using χ2 tests. The genotype-phenotype relationship among gout patients was tested by analysis of variance. There was a significant difference in genotypic frequencies of IL-23R rs10889677 between gout patients and controls (χ2 = 81.386, P < 0.001). However, there were no significant differences in distributions of the other polymorphisms between the groups. Our results revealed that the rs10889677 variant in IL-23R may be involved in the development of gout in Chinese Han male individuals. However, further studies in other ethnic groups are needed to confirm these results.
Tunable mid-infrared coherent perfect absorption in a graphene meta-surface
Authors: Fan Yuancheng , Liu Zhe , Zhang Fuli , Zhao Qian , Wei Zeyong , Fu Quanhong , Li Junjie , Gu Changzhi , Li Hongqiang
Published: September 2015

Graphene has drawn considerable attention due to its intriguing properties in photonics and optoelectronics. However, its interaction with light is normally rather weak. Meta-surfaces, artificial structures with single planar function-layers, have demonstrated exotic performances in boosting light-matter interactions, e.g., for absorption enhancement. Graphene based high efficiency absorber is desirable for its potential applications in optical detections and signal modulations. Here we exploit graphene nanoribbons based meta-surface to realize coherent perfect absorption (CPA) in the mid-infrared regime. It was shown that quasi-CPA frequencies, at which CPA can be demonstrated with proper phase modulations, exist for the grapheme meta-surface with strong resonant behaviors. The CPA can be tuned substantially by merging the geometric design of the meta-surface and the electrical tunability of graphene. Furthermore, we found that the graphene nanoribbon meta-surface based CPA is realizable with experimentally achievable graphene sample.
Opposite Effects of M1 and M2 Macrophage Subtypes on Lung Cancer Progression
Authors: Yuan Ang , Hsiao Yi-Jing , Chen Hsuan-Yu , Chen Huei-Wen , Ho Chao-Chi , Chen Yu-Yun , Liu Yi-Chia , Hong Tsai-Hsia , Yu Sung-Liang , Chen Jeremy J.W. , Yang Pan-Chyr
Published: September 2015

Macrophages in a tumor microenvironment have been characterized as M1- and M2-polarized subtypes. Here, we discovered the different macrophages’ impacts on lung cancer cell A549. The M2a/M2c subtypes promoted A549 invasion and xenograft tumor growth. The M1 subtype suppressed angiogenesis. M1 enhanced the sensitivity of A549 to cisplatin and decreased the tube formation activity and cell viability of A549 cells by inducing apoptosis and senescence. Different macrophage subtypes regulated genes involved in the immune response, cytoskeletal remodeling, coagulation, cell adhesion and apoptosis pathways in A549 cells, which was a pattern that correlated with the altered behaviors of the A549 cells. Furthermore, we found that the identified M1/M2 gene signatures were significantly correlated with the extended overall survival of lung cancer patients. These results suggest that M1/M2 gene expression signature may be used as a prognostic indicator for lung cancer patients and M1/M2 polarization may be a target of investigation of immune-modulating therapies for lung cancer in the future.
Starvation-Induced Dietary Behaviour in Drosophila melanogaster Larvae and Adults
Authors: Ahmad Muhammad , Chaudhary Safee Ullah , Afzal Ahmed Jawaad , Tariq Muhammad
Published: September 2015

Drosophila melanogasterlarvae are classified as herbivores and known to feed on non-carnivorous diet under normal conditions. However, when nutritionally challenged these larvae exhibit cannibalistic behaviour by consuming a diet composed of larger conspecifics. Herein, we report that cannibalism inDrosophilalarvae is confined not only to scavenging on conspecifics that are larger in size, but also on their eggs. Moreover, such cannibalistic larvae develop as normally as those grown on standard cornmeal medium. When stressed,Drosophila melanogasterlarvae can also consume a carnivorous diet derived from carcasses of organisms belonging to diverse taxonomic groups, includingMusca domestica,Apis melliferaandLycosidae sp. While adults are ill-equipped to devour conspecific carcasses, they selectively oviposit on them and also consume damaged cadavers of conspecifics. Thus, our results suggest that nutritionally stressedDrosophilashow distinct as well as unusual feeding behaviours that can be classified as detritivorous, cannibalistic and/or carnivorous.
A novel stearic acid-modified hirudin peptidomimetic with improved pharmacokinetic properties and anticoagulant activity
Authors: Liu Zhuguo , Yu Zheng , Huang Yuanyuan , Zhang Yan , Han Guozhu , Li Xian , Dong Mingxin , Yu Shuo , Wang Yu , Hu Jie , Guo Huiqin , Cheng Yuanguo , Lv Li , Dai Qiuyun
Published: September 2015

A novel hirudin isoform 3 mimetic peptide, named peptide S2, has been prepared by introduction of a stearic acid modification. Peptide S2 exhibited superior inhibitory activity to hirulog-1 (Bivariludin) and showed significantly higher anticoagulant potency in vivo. Peptide S2 elevated the thrombin time, prothrombin time and activated partial thromboplastin time of rat and human plasma more efficiently than hirulog-1 and the unmodified form of peptide S2 (peptide 1). Furthermore, peptide S2 inhibited arterial thrombosis and inferior vena cava in rat model 8 h after administration and was 10-fold more potent than hirulog-1 300 min after administration of 0.1 μmol/kg peptide. The enhanced antithrombotic activity could be attributed to its long half-life (T1/2 = 212.2 ± 58.4 min), which was 13.1 and 14.7-fold longer than those of hirulog-1 (T1/2 = 15.1 ± 1.3 min) and peptide 1 (T1/2 = 13.5 ± 2.6 min), respectively. Further enzymatic degradation and binding assay with human serum albumin (HSA) demonstrated that the longer duration time should be originated from the slowing of trypsin or thrombin–mediated degradation, as well as its binding to HSA. The improved pharmacokinetic properties observed for peptide S2 has made it a promising therapeutic agent for the treatment of thrombi-related diseases.
When fur and feather occur together: interclass transmission of avian influenza A virus from mammals to birds through common resources
Authors: Jeffrey Root J. , Shriner Susan A. , Ellis Jeremy W. , VanDalen Kaci K. , Sullivan Heather J. , Franklin Alan B.
Published: September 2015

The potential role of wild mammals in avian influenza A virus (IAV) transmission cycles has received some attention in recent years and cases where birds have transmitted IAV to mammals have been documented. However, the contrasting cycle, wherein a mammal could transmit an avian IAV to birds, has been largely overlooked. We experimentally tested the abilities of two mammalian species to transmit avian IAV to mallards (Anas platyrhynchos) in simulated natural environments. Results suggested that striped skunks (Mephitis mephitis) can successfully transmit avian IAV to mallards through indirect contact with shared resources, as transmission was noted in 1 of 4 of the mallards tested. Cottontail rabbits (Sylvilagus sp.) exhibited a similar pattern, as one of five cottontail rabbits successfully transmitted IAV to a mallard, likely through environmental contamination. For each mammalian species tested, the mallards that became infected were those paired with the individual mammals with the lowest shedding levels but were anecdotally observed to be the most active animals. Mammals associated with and around poultry rearing facilities should be taken into consideration in biosecurity plans.
Ab initio molecular dynamics of liquid water using embedded-fragment second-order many-body perturbation theory towards its accurate property prediction
Authors: Willow Soohaeng Yoo , Salim Michael A. , Kim Kwang S. , Hirata So
Published: September 2015

A direct, simultaneous calculation of properties of a liquid using an ab initio electron-correlated theory has long been unthinkable. Here we present structural, dynamical and response properties of liquid water calculated by ab initio molecular dynamics using the embedded-fragment spin-component-scaled second-order many-body perturbation method with the aug-cc-pVDZ basis set. This level of theory is chosen as it accurately and inexpensively reproduces the water dimer potential energy surface from the coupled-cluster singles, doubles and noniterative triples with the aug-cc-pVQZ basis set, which is nearly exact. The calculated radial distribution function, self-diffusion coefficient, coordinate number and dipole moment, as well as the infrared and Raman spectra are in excellent agreement with experimental results. The shapes and widths of the OH stretching bands in the infrared and Raman spectra and their isotropic-anisotropic Raman noncoincidence, which reflect the diverse local hydrogen-bond environment, are also reproduced computationally. The simulation also reveals intriguing dynamic features of the environment, which are difficult to probe experimentally, such as a surprisingly large fluctuation in the coordination number and the detailed mechanism by which the hydrogen donating water molecules move across the first and second shells, thereby causing this fluctuation.
Pathogenic Escherichia coli producing Extended-Spectrum β-Lactamases isolated from surface water and wastewater
Authors: Franz Eelco , Veenman Christiaan , van Hoek Angela H. A. M. , Husman Ana de Roda , Blaak Hetty
Published: September 2015

To assess public health risks from environmental exposure to Extended-Spectrum β-Lactamases (ESBL)-producing bacteria, it is necessary to have insight in the proportion of relative harmless commensal variants and potentially pathogenic ones (which may directly cause disease). In the current study, 170 ESBL-producing E. coli from Dutch wastewater (n = 82) and surface water (n = 88) were characterized with respect to ESBL-genotype, phylogenetic group, resistance phenotype and virulence markers associated with enteroaggregative E. coli (EAEC), enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), extraintesinal E. coli (ExPEC) and Shiga toxin-producing E. coli (STEC). Overall, 17.1% of all ESBL-producing E. coli were suspected pathogenic variants. Suspected ExPECs constituted 8.8% of all ESBL-producing variants and 8.3% were potential gastrointestinal pathogens (4.1% EAEC, 1.8% EPEC, 1.2% EIEC, 1.2% ETEC, no STEC). Suspected pathogens were significantly associated with ESBL-genotype CTX-M-15 (X2 = 14.7, P < 0.001) and phylogenetic group B2 (X2 = 23.5, P < 0.001). Finally, 84% of the pathogenic ESBL-producing E. coli isolates were resistant to three or more different classes of antibiotics. In conclusion, this study demonstrates that the aquatic environment is a potential reservoir of E. coli variants that combine ESBL-genes, a high level of multi-drug resistance and virulence factors and therewith pose a health risk to humans upon exposure.
Longitudinal tracking of single live cancer cells to understand cell cycle effects of the nuclear export inhibitor, selinexor
Authors: Marcus Joshua M. , Burke Russell T. , DeSisto John A. , Landesman Yosef , Orth James D.
Published: September 2015

Longitudinal tracking is a powerful approach to understand the biology of single cells. In cancer therapy, outcome is determined at the molecular and cellular scale, yet relationships between cellular response and cell fate are often unknown. The selective inhibitor of nuclear export, selinexor, is in development for the treatment of various cancers. Selinexor covalently binds exportin-1, causing nuclear sequestration of cargo proteins, including key regulators of the cell cycle and apoptosis. The cell cycle effects of selinexor and the relationships between cell cycle effects and cell fates, has not been described for individual cells. Using fluorescent cell cycle indicators we report the majority of cell death after selinexor treatment occurs from a protracted G1-phase and early S-phase. G1- or early S-phase treated cells show the strongest response and either die or arrest, while those treated in late S- or G2-phase progress to mitosis and divide. Importantly, the progeny of cell divisions also die or arrest, mostly in the next G1-phase. Cells that survive selinexor are negative for multiple proliferation biomarkers, indicating a penetrant, arrested state. Selinexor acts quickly, shows strong cell cycle selectivity and is highly effective at arresting cell growth and inducing death in cancer-derived cells.
Preserving low perfusion during surgical liver blood inflow control prevents hepatic microcirculatory dysfunction and irreversible hepatocyte injury in rats
Authors: Li Chong-Hui , Chen Yong-Wei , Chen Yong-Liang , Yao Li-Bin , Ge Xin-Lan , Pan Ke , Zhang Ai-Qun , Dong Jia-Hong
Published: September 2015

Hepatic ischaemia/reperfusion (I/R) injury is of primary concern during liver surgery. We propose a new approach for preserving low liver blood perfusion during hepatectomy either by occlusion of the portal vein (OPV) while preserving hepatic artery flow or occlusion of the hepatic artery while limiting portal vein (LPV) flow to reduce I/R injury. The effects of this approach on liver I/R injury were investigated. Rats were randomly assigned into 4 groups: sham operation, occlusion of the portal triad (OPT), OPV and LPV. The 7-day survival rate was significantly improved in the OPV and LPV groups compared with the OPT group. Microcirculatory liver blood flow recovered rapidly after reperfusion in the OPV and LPV groups but decreased further in the OPT group. The OPV and LPV groups also showed much lower ALT and AST levels, Suzuki scores, inflammatory gene expression levels and parenchymal necrosis compared with the OPT group. An imbalance between the expression of vasoconstriction and vasodilation genes was observed in the OPT group but not in the OPV or LPV group. Therefore, preserving low liver blood perfusion by either the OPV or LPV methods during liver surgery is very effective for preventing hepatic microcirculatory dysfunction and hepatocyte injury.