bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Recruitment Dynamics of Alewife and Bloater in Lakes Michigan and Huron
Authors: Collingsworth Paris D. , Bunnell David B. , Madenjian Charles P. , Riley Stephen C.
Published: January 2014

The predictive power of recruitment models often relies on the identification and quantification of external variables, in addition to stock size. In theory, the identification of climatic, biotic, or demographic influences on reproductive success assists fisheries management by identifying factors that have a direct and reproducible influence on the population dynamics of a target species. More often, models are constructed as one‐time studies of a single population whose results are not revisited when further data become available. Here, we present results from stock recruitment models for Alewife Alosa pseudoharengus and Bloater Coregonus hoyi in Lakes Michigan and Huron. The factors that explain variation in Bloater recruitment were remarkably consistent across populations and with previous studies that found Bloater recruitment to be linked to population demographic patterns in Lake Michigan. Conversely, our models were poor predictors of Alewife recruitment in Lake Huron but did show some agreement with previously published models from Lake Michigan. Overall, our results suggest that external predictors of fish recruitment are difficult to discern using traditional fisheries models, and reproducing the results from previous studies may be difficult particularly at low population sizes.
Use of Genetic Stock Identification Data for Comparison of the Ocean Spatial Distribution, Size at Age, and Fishery Exposure of an Untagged Stock and Its Indicator: California Coastal versus Klamath River Chinook Salmon
Authors: Satterthwaite William H. , Mohr Michael S. , O'Farrell Michael R. , Anderson Eric C. , Banks Michael A. , Bates Sarah J. , Bellinger M. Renee , Borgerson Lisa A. , Crandall Eric D. , Garza John Carlos , Kormos Brett J. , Lawson Peter W. , Palmer‐Zwahlen Melodie L.
Published: January 2014

Managing weak stocks in mixed‐stock fisheries often relies on proxies derived from data‐rich indicator stocks, although there have been limited tests of the appropriateness of such proxies. For example, full cohort reconstruction of tagged Klamath River fall‐run Chinook Salmon Oncorhynchus tshawytscha of northern California enables the use of detailed models to inform management. Information gained from this stock is also used in the management of the untagged, threatened California Coastal Chinook Salmon (CCC) stock, where it is assumed that a cap on Klamath harvest rates effectively constrains impacts on CCC to acceptable levels. To evaluate use of this proxy, we used a novel approach based on genetic stock identification (GSI) data to compare the two stocks’ size at age and ocean distribution (as inferred from spatial variation in CPUE), two key factors influencing fishery exposure. We developed broadly applicable methods to account for both sampling and genetic assignment uncertainty in estimating total stock‐specific catch from GSI data, and propagated this uncertainty into models quantifying variation in CPUE across space and time. We found that, in 2010, the stocks were similar in size at age early in the year (age 3 and age 4), but CCC fish were larger later in the year. The stocks appeared similarly distributed early in the year (2010) but more concentrated near their respective source rivers later in the year (2010 and 2011). If these results are representative, relative fishery impacts on the two stocks might scale similarly early in the year, but management changes later in the year could have differing impacts on the two stocks. This novel modeling approach is suited to evaluating the concordance between other data‐limited stocks and their proxies, and can be broadly applied to estimate stock‐specific harvest, and the uncertainty therein, using GSI in other systems.
CXCR4 drives the metastatic phenotype in breast cancer through induction of CXCR2 and activation of MEK and PI3K pathways
Authors: Sobolik Tammy , Su Ying-jun , Wells Sam , Ayers Gregory D. , Cook Rebecca S. , Richmond Ann
Published: January 2014

Aberrant expression of CXCR4 in human breast cancer correlates with metastasis to tissues secreting CXCL12. To understand the mechanism by which CXCR4 mediates breast cancer metastasis, MCF-7 breast carcinoma cells were transduced to express wild-type CXCR4 (CXCR4WT) or constitutively active CXCR4 (CXCR4ΔCTD) and analyzed in two-dimensional (2D) cultures, three-dimensional reconstituted basement membrane (3D rBM) cultures, and mice using intravital imaging. Two-dimensional cultures of MCF-7 CXCR4ΔCTD cells, but not CXCR4WT, exhibited an epithelial-to-mesenchymal transition (EMT) characterized by up-regulation of zinc finger E box–binding homeobox 1, loss of E-cadherin, up-regulation of cadherin 11, p120 isoform switching, activation of extracellular signal-regulated kinase 1/2, and matrix metalloproteinase-2. In contrast to the 2D environment, MCF-7 CXCR4WT cells cultured in 3D rBM exhibited an EMT phenotype, accompanied by expression of CXCR2, CXCR7, CXCL1, CXCL8, CCL2, interleukin-6, and granulocyte–macrophage colony stimulating factor. Dual inhibition of CXCR2 with CXCR4, or inhibition of either receptor with inhibitors of mitogen-activated protein kinase 1 or phosphatidylinositol 3-kinase, reversed the aggressive phenotype of MCF-7 CXCR4-expressing or MDA-MB-231 cells in 3D rBM. Intravital imaging of CXCR4-expressing MCF-7 cells revealed that tumor cells migrate toward blood vessels and metastasize to lymph nodes. Thus CXCR4 can drive EMT along with an up-regulation of chemokine receptors and cytokines important in cell migration, lymphatic invasion, and tumor metastasis.
IDO2 is critical for IDO1-mediated T-cell regulation and exerts a non-redundant function in inflammation
Authors: Metz Richard , Smith Courtney , DuHadaway James B. , Chandler Phillip , Baban Babak , Merlo Lauren M. F. , Pigott Elizabeth , Keough Martin P. , Rust Sonja , Mellor Andrew L. , Mandik-Nayak Laura , Muller Alexander J. , Prendergast George C.
Published: January 2014

IDO2 is implicated in tryptophan catabolism and immunity but its physiological functions are not well established. Here we report the characterization of mice genetically deficient in IDO2, which develop normally but exhibit defects in IDO-mediated T-cell regulation and inflammatory responses. Construction of this strain was prompted in part by our discovery that IDO2 function is attenuated in macrophages from Ido1−/− mice due to altered message splicing, generating a functional mosaic with implications for interpreting findings in Ido1–/– mice. No apparent defects were observed in Ido2–/– mice in embryonic development or hematopoietic differentiation, with wild-type profiles documented for kynurenine in blood serum and for immune cells in spleen, lymph nodes, peritoneum, thymus and bone marrow of naive mice. In contrast, upon immune stimulation we determined that IDO1-dependent T regulatory cell generation was defective in Ido2−/− mice, supporting Ido1–Ido2 genetic interaction and establishing a functional role for Ido2 in immune modulation. Pathophysiologically, both Ido1−/− and Ido2−/− mice displayed reduced skin contact hypersensitivity responses, but mechanistic distinctions were apparent, with only Ido2 deficiency associated with a suppression of immune regulatory cytokines that included GM-CSF, G-CSF, IFN-γ, TNF-α, IL-6 and MCP-1/CCL2. Different contributions to inflammation were likewise indicated by the finding that Ido2−/− mice did not phenocopy Ido1−/− mice in the reduced susceptibility of the latter to inflammatory skin cancer. Taken together, our results offer an initial glimpse into immune modulation by IDO2, revealing its genetic interaction with IDO1 and distinguishing its non-redundant contributions to inflammation.
Involvement of histamine 4 receptor in the pathogenesis and progression of rheumatoid arthritis
Authors: Abd-Allah Adel R. A. , Ahmad Sheikh Fayaz , Alrashidi Ibrahim , Abdel-Hamied Hala E. , Zoheir Khairy M. A. , Ashour Abdelkader E. , Bakheet Saleh A. , Attia Sabry M.
Published: January 2014

Rheumatoid arthritis (RA) is one of the major autoimmune diseases with a global prevalence. Despite significant research into this disease, no drugs with acceptable safety profiles are yet available for its treatment. We investigated the possible anti-arthritic effects of the 4-methylhistamine (4-MeH) histamine 4 receptor (H4R) agonist and the JNJ77777120 (JNJ) H4R antagonist to explore the role of H4R in a mouse model of collagen antibody-induced arthritis (CAIA). Arthritis was induced via intravenous (tail vein) injection of Balb/c mice with a 5-clone cocktail of mAbs against collagen type II, followed by LPS, and the effects of treatment with 4-MeH or JNJ (30mg kg−1, i.p, twice daily) for 7 days (prophylactic or therapeutic regimens) were assessed. The results revealed increased paw edema, arthritic scores, joint histological inflammatory damage and matrix metalloproteinase-3 levels and high levels of Th1 pro-inflammatory cytokine mRNA and serum proteins in CAIA mice or following H4R activation via 4-MeH. Additionally, 4-MeH efficiently increased expression levels of NF-κB p65. JNJ-treated mice showed a substantial reduction in all the previously mentioned effects, with a similar trend being observed under prophylactic and therapeutic treatment regimens. The results of the present work indicate that JNJ exhibits significant anti-inflammatory and anti-arthritic activities, demonstrating the clear involvement of H4R antagonism in the pathogenesis and progression of RA.
Evolutionary search for new high-kdielectric materials: methodology and applications to hafnia-based oxides
Authors: Zeng Qingfeng , Oganov Artem R. , Lyakhov Andriy O. , Xie Congwei , Zhang Xiaodong , Zhang Jin , Zhu Qiang , Wei Bingqing , Grigorenko Ilya , Zhang Litong , Cheng Laifei
Published: January 2014

High-kdielectric materials are important as gate oxides in microelectronics and as potential dielectrics for capacitors. In order to enable computational discovery of novel high-kdielectric materials, we propose a fitness model (energy storage density) that includes the dielectric constant, bandgap, and intrinsic breakdown field. This model, used as a fitness function in conjunction with first-principles calculations and the global optimization evolutionary algorithm USPEX, efficiently leads to practically important results. We found a number of high-fitness structures of SiO2and HfO2, some of which correspond to known phases and some of which are new. The results allow us to propose characteristics (genes) common to high-fitness structures – these are the coordination polyhedra and their degree of distortion. Our variable-composition searches in the HfO2–SiO2system uncovered several high-fitness states. This hybrid algorithm opens up a new avenue for discovering novel high-kdielectrics with both fixed and variable compositions, and will speed up the process of materials discovery.
Bis{2-[(3,5-diphenyl-1H-pyrrol-2-ylidene-κN)amino]-3,5-diphenylpyrrol-1-ido-κN}palladium(II): a homoleptic four-coordinate tetraphenylazadipyrromethene complex of palladium
Authors: Jones Roderick C. , Müller-Bunz Helge , Evans Paul , O'Shea Donal F.
Published: January 2014

The structural chemistry of the title compound, [Pd(C32H22N3)2], at 173 K is described. The compound is comprised of two deprotonated (3,5-diphenyl-1H-pyrrol-2-yl)(3,5-diphenylpyrrol-2-ylidene)amine ligands coordinated to a central PdIIcation, which lies on an inversion centre and has distorted square-planar geometry. The Pd—N bond lengths range from 2.008 (4) to 2.014 (4) Å and the bite angle is 84.16 (14)°. The chelate plane makes a dihedral angle of 45.3 (2)° with respect to the central PdN4plane, giving a stepped conformation to the molecule. The complex displays simple intramolecular C—H...N hydrogen bonds, while the unit cell consists of discrete monomeric Pd(C32H22N3)2units which display intermolecular C—H...π interactions and limited intra- and intermolecular π–π stacking.
Positron emission tomography‐computed tomography on predicting the efficacy of targeted therapy for lung adenocarcinoma
Authors: Rong Xiaoxiang , Cai Xiaoli , Li Rong , Chen Jinzhang , Wang Quanshi , You Changxuan , Wu Wenyun , Liu Chuanxin , Zhang Junyi , Luo Rongcheng
Published: January 2014

Background

In this study, positron emission tomography‐computed tomography (PET‐CT) was used to monitor the maximal standard uptake value (SUVmax) in advanced lung adenocarcinoma patients with epithermal growth factor receptor (EGFR) mutation to prove its role in predicting the prognosis of targeted therapy.

Methods

A total of 46 patients with advanced lung adenocarcinoma (IIIb‐IV stage) were enrolled in the current study. They were positive for EGFR mutation. All patients received gefitinib (250 mg per day, administered orally). PET‐CT was conducted prior to (at baseline) and six months after gefitinib administration for the lesion size and SUVmax. The recommendations of the European Organization for Research and Treatment of Cancer criteria were chosen for PET assessment. Metabolic response (SUV decline < −25%) was compared with morphologic response evaluated by CT scan and overall survival.

Result

Compared to patients with △SUV% ≥ 25% (progressive metabolic disease), the survival time was significantly prolonged in △SUV% < −25% (including complete metabolic response and progressive metabolic disease) (10.6/18.4, P = 0.000), but was not in −25% ≤ △SUV% < 25% (stable metabolic disease) (10.6/10.7, P = 0.088). Patients who achieved △SUV% < −25% after treatment were associated with a longer median survival, higher control rate, and better prognosis. There was a strong correlation between SUV changes (△SUV%) and CT size change (△lesion size%) (R2 = 0.891, P = 0.000).

Conclusion

Changes in the SUV could be used to predict the prognosis of targeted therapy in advanced lung adenocarcinoma.
Are minority status children's cross‐ethnic friendships beneficial in a multiethnic context?
Authors: Bagci Sabahat C. , Rutland Adam , Kumashiro Madoka , Smith Peter K. , Blumberg Herbert
Published: January 2014

Past research has demonstrated the negative impact of perceived ethnic discrimination (PED) on psychological well‐being among children. Given research demonstrating the benefits of cross‐ethnic friendship for children's intergroup attitudes, we examined whether cross‐ethnic friendships would attenuate the effects of PED on well‐being and resilience within a multi‐ethnic context. Two hundred and forty‐seven South Asian British children (M = 11 years) recruited from 37 classrooms completed measures of perceived cross‐ethnic friendship quantity and quality, PED, psychological well‐being, and resilience. Friendship quality, but not quantity, had direct positive associations with psychological well‐being and resilience. A higher quantity of cross‐ethnic friendships moderated the negative effects of PED on both outcomes. Results suggest that cross‐ethnic friendships are beneficial for South Asian British children by functioning as a protective factor from the negative effects of discrimination within a multi‐ethnic context.
Can creative podcasting promote deep learning? The use of podcasting for learning content in an undergraduate science unit
Authors: Pegrum Mark , Bartle Emma , Longnecker Nancy
Published: January 2014

This paper examines the effect of a podcasting task on the examination performance of several hundred first‐year chemistry undergraduate students. Educational researchers have established that a deep approach to learning that promotes active understanding of meaning can lead to better student outcomes, higher grades and superior retention of knowledge over time. We attempted to promote such an approach by setting a task that involved student collaboration, contextualisation of content, and communication through new media, specifically creative podcasting.

Examination results were used as a source of empirical evidence of changes in understanding and retention that occurred for students who completed this task. In comparing results across 2 years on similar questions related to the podcasting topics, we found a statistically significant improvement after introduction of the podcasting task on the questions related to one of the topics on which students had actively created their own podcasts (“acids & bases”), but not on the other (“oxidisation and reduction”). Improved learning outcomes in the form of better understanding and retention over time in at least one case suggest that under some circumstances creative podcasting may indeed help to promote a deep learning approach.
Cost‐Effectiveness of Alternative Conservation Strategies with Application to the Pacific Leatherback Turtle
Authors: GJERTSEN HEIDI , SQUIRES DALE , DUTTON PETER H. , EGUCHI TOMOHARU
Published: January 2014

Although holistic conservation addressing all sources of mortality for endangered species or stocks is the preferred conservation strategy, limited budgets require a criterion to prioritize conservation investments. We compared the cost‐effectiveness of nesting site and at‐sea conservation strategies for Pacific leatherback turtles (Dermochelys coriacea). We sought to determine which conservation strategy or mix of strategies would produce the largest increase in population growth rate per dollar. Alternative strategies included protection of nesters and their eggs at nesting beaches in Indonesia, gear changes, effort restrictions, and caps on turtle takes in the Hawaiian (U.S.A.) longline swordfish fishery, and temporal and area closures in the California (U.S.A.) drift gill net fishery. We used a population model with a biological metric to measure the effects of conservation alternatives. We normalized all effects by cost to prioritize those strategies with the greatest biological effect relative to its economic cost. We used Monte Carlo simulation to address uncertainty in the main variables and to calculate probability distributions for cost‐effectiveness measures. Nesting beach protection was the most cost‐effective means of achieving increases in leatherback populations. This result creates the possibility of noncompensatory bycatch mitigation, where high‐bycatch fisheries invest in protecting nesting beaches. An example of this practice is U.S. processors of longline tuna and California drift gill net fishers that tax themselves to finance low‐cost nesting site protection. Under certain conditions, fisheries interventions, such as technologies that reduce leatherback bycatch without substantially decreasing target species catch, can be cost‐effective. Reducing bycatch in coastal areas where bycatch is high, particularly adjacent to nesting beaches, may be cost‐effective, particularly, if fisheries in the area are small and of little commercial value.

Rentabilidad de Estrategias de Conservación Alternativas Aplicadas a Tortugas Laúd del Pacífico
Total carbon and nitrogen in the soils of the world
Authors: Batjes N. H.
Published: January 2014

The soil is important in sequestering atmospheric CO2 and in emitting trace gases (e.g. CO2, CH4 and N2O) that are radiatively active and enhance the ‘greenhouse’ effect. Land use changes and predicted global warming, through their effects on net primary productivity, the plant community and soil conditions, may have important effects on the size of the organic matter pool in the soil and directly affect the atmospheric concentration of these trace gases.

A discrepancy of approximately 350 × 1015 g (or Pg) of C in two recent estimates of soil carbon reserves worldwide is evaluated using the geo‐referenced database developed for the World Inventory of Soil Emission Potentials (WISE) project. This database holds 4353 soil profiles distributed globally which are considered to represent the soil units shown on a ½º latitude by ½º longitude version of the corrected and digitized 1 : 5 M FAO–UNESCO Soil Map of the World.

Total soil carbon pools for the entire land area of the world, excluding carbon held in the litter layer and charcoal, amounts to 2157–2293 Pg of C in the upper 100 cm. Soil organic carbon is estimated to be 684–724 Pg of C in the upper 30 cm, 1462–1548 Pg of C in the upper 100 cm, and 2376–2456 Pg of C in the upper 200 cm. Although deforestation, changes in land use and predicted climate change can alter the amount of organic carbon held in the superficial soil layers rapidly, this is less so for the soil carbonate carbon. An estimated 695–748 Pg of carbonate‐C is held in the upper 100 cm of the world's soils. Mean C : N ratios of soil organic matter range from 9.9 for arid Yermosols to 25.8 for Histosols. Global amounts of soil nitrogen are estimated to be 133–140 Pg of N for the upper 100 cm. Possible changes in soil organic carbon and nitrogen dynamics caused by increased concentrations of atmospheric CO2 and the predicted associated rise in temperature are discussed.
Progressive damage modelling of 3D fully interlaced woven composite materials
Authors: Koumpias A. S. , Tserpes K. I. , Pantelakis S.
Published: January 2014

A progressive damage model (PDM) was developed to simulate the mechanical behaviour and predict strength of 3D fully interlaced woven composite materials. The PDM was applied at the micro‐scale on a homogenised representative volume element (RVE) of the woven material created using the geometry pre‐processor software TexGen. The PDM consists of three modules, namely stress analysis, failure analysis and material property degradation. Stress analysis of the RVE was performed using the finite element method. Failure analysis within the tows was performed using a set of Hashin‐type failure criteria. Material property degradation in the failed elements of the tows was applied using a damage mechanics‐based strain‐softening law. The non‐linear mechanical behaviour of the matrix was simulated using a multi‐linear continuum damage model. The PDM was validated successfully against experimental results from the literature. The mechanical behaviour of the 3D woven composite material was fully characterised by loading the RVE into uniaxial tension and compression in the three axes, and shear in the three planes. The proposed PDM can be used to numerically characterise any type of 3D woven composite material. Furthermore, as the computed mechanical properties of the material are representative at the macro‐scale, they can be used as input to simulation of structural parts made from the specific composite material.
System, scholar or students? Which most influences online MBA course effectiveness?
Authors: Arbaugh J.B.
Published: January 2014

Considering the increasingly challenging resource environments in many business schools, this study examined whether course technologies, learner behaviors or instructor behaviors best predict online course outcomes so that administrators and support personnel can prioritize their efforts and investments. Based on reviewing prior online and blended management education literature, we hypothesized that instructor behaviors would be most predictive of online course outcomes. However, our study of 48 online Master of Business Administration courses found that although instructor behaviors (operationalized as teaching presence) was the strongest predictor of any of our three outcome variables (perceived learning), only student behaviors (operationalized as social presence) significantly predicted all three (course grades, perceived learning and delivery medium satisfaction). Technological characteristics, operationalized using variables from the technology acceptance model and media variety, predicted perceived learning (perceived ease of use) and delivery medium satisfaction (perceived usefulness). The paper provides recommendations for instructors and administrators based on the findings, specifically advocating for a balance between instructor and administrator involvement in course design, presentation and conduct. The paper concludes by describing research opportunities regarding the roles of social presence in and collaborative approaches to online learning in business schools.
Brugada Syndrome: A Heterogeneous Disease with a Common ECG Phenotype?
Authors: GRAY BELINDA , SEMSARIAN CHRISTOPHER , SY RAYMOND W.
Published: January 2014

Brugada Syndrome

Our understanding of Brugada syndrome (BrS) has evolved since the syndrome was first described in 1992. BrS is considered to be a primary inherited channelopathy often involving the inward sodium current and the diagnosis has traditionally required the exclusion of overt structural heart disease.

In view of recently published observations about BrS, we propose that the term BrS may actually encompass a heterogeneous group of disorders with a variety of genetic and clinical phenotypes. This disease has classically been described as a primary electrical disorder involving the sodium channel leading to the characteristic electrocardiogram (ECG) changes of BrS. We challenge the current understanding and propose that patients with structurally normal hearts, family history of sudden cardiac death, with associated genetic abnormalities only account for a subset of patients with the “Brugada pattern” ECG. There may also be some patients with a diagnosis of BrS who may also have features which overlap with arrhythmogenic right ventricular cardiomyopathy. In these patients there may be an underlying structural abnormality. In this context, it is possible that catheter ablation may abolish the “Brugada pattern” ECG changes as well as abolishing the risk of life threatening arrhythmias in these patients.

Given the recent developments in the field, we propose a novel comprehensive multimodality model for risk stratification and assessment of patients with BrS. Identification of variations of diseases may facilitate more specific risk stratification models and management paradigms in patients with Brugada ECG pattern.
The perplexing role of autophagy in plant innate immune responses
Authors: Zhou Jie , Yu Jing‐Quan , Chen Zhixiang
Published: January 2014

Autophagy is a major intracellular process for the degradation of cytosolic macromolecules and organelles in the lysosomes or vacuoles for the purposes of regulating cellular homeostasis and protein and organelle quality control. In complex metazoan organisms, autophagy is highly engaged during the immune responses through interfaces either directly with intracellular pathogens or indirectly with immune signalling molecules. Studies over the last decade or so have also revealed a number of important ways in which autophagy shapes plant innate immune responses. First, autophagy promotes defence‐associated hypersensitive cell death induced by avirulent or related pathogens, but restricts unnecessary or disease‐associated spread of cell death. This elaborate regulation of plant host cell death by autophagy is critical during plant immune responses to the types of plant pathogens that induce cell death, which include avirulent biotrophic pathogens and necrotrophic pathogens. Second, autophagy modulates defence responses regulated by salicylic acid and jasmonic acid, thereby influencing plant basal resistance to both biotrophic and necrotrophic pathogens. Third, there is an emerging role of autophagy in virus‐induced RNA silencing, either as an antiviral collaborator for targeted degradation of viral RNA silencing suppressors or an accomplice of viral RNA silencing suppressors for targeted degradation of key components of plant cellular RNA silencing machinery. In this review, we summarize this important progress and discuss the potential significance of the perplexing role of autophagy in plant innate immunity.
Status and Ecological Effects of the World’s Largest Carnivores
Authors: Ripple William J. , Estes James A. , Beschta Robert L. , Wilmers Christopher C. , Ritchie Euan G. , Hebblewhite Mark , Berger Joel , Elmhagen Bodil , Letnic Mike , Nelson Michael P. , Schmitz Oswald J. , Smith Douglas W. , Wallach Arian D. , Wirsing Aaron J.
Published: January 2014

Preserving Predators

Large-bodied animals play essential roles in ecosystem structuring and stability through both indirect and direct trophic effects. In recent times, humans have disrupted this trophic structure through both habitat destruction and active extirpation of large predators, resulting in large declines in numbers and vast contractions in their geographic ranges.

Ripple
et al.

(
10.1126/science.1241484
; see the Perspective by

Roberts

) review the status, threats, and ecological importance of the 31 largest mammalian carnivores globally. These species are responsible for a suite of direct and indirect stabilizing effects in ecosystems. Current levels of decline are likely to result in ecologically ineffective population densities and can lead to ecosystem instability. The preservation of large carnivores can be challenging because of their need for large ranges and their potential for human conflict. However, the authors demonstrate that the preservation of large carnivores is ecologically important and that the need for conservation action is immediate, given the severity of the threats they face.
Performing Mathematical Operations with Metamaterials
Authors: Silva Alexandre , Monticone Francesco , Castaldi Giuseppe , Galdi Vincenzo , Alù Andrea , Engheta Nader
Published: January 2014

Computational Metamaterials

Optical signal processing of light waves can represent certain mathematical functions and perform computational tasks on signals or images in an analog fashion. However, the complex systems of lenses and filters required are bulky. Metamaterials can perform similar optical processing operations but with materials that need only be a wavelength thick.

Silva
et al.

(p.
160
; see the Perspective by

Sihvola

) present a simulation study that shows how an architecture based on such metamaterials can be designed to perform a suite of mathematical functions to create ultrathin optical signal and data processors.
Apical Abscission Alters Cell Polarity and Dismantles the Primary Cilium During Neurogenesis
Authors: Das Raman M. , Storey Kate G.
Published: January 2014

Developing Neurons Make the Cut

Neurons in the developing central nervous system of vertebrates derive from cells adjacent to the ventricles that then proliferate and differentiate to populate the brain. As one of these cells begins to differentiate, the cell nucleus migrates toward its new residence, away from the ventricle surface, and the cell stretches out. At some point, like any maturing adolescent, the cell has to leave home.
Das and Storey
(p.
200
; see the Perspective by

Tozer and Morin

) show that instead of letting go and drawing the trailing process up into the migrating cell, the cell cuts off and discards its first roots. The abscission process leaves behind the primary cilium and any signaling systems localized to the cilium.
Young Neurons Sever Ties to the Parental Niche
Authors: Tozer Samuel , Morin Xavier
Published: January 2014

Neuronal precursor cells of the vertebrate central nervous system shed an apical end-foot to differentiate.

[Also see Report by
Das and Storey
]
Evaluation of the AID TB Resistance Line Probe Assay for Rapid Detection of Genetic Alterations Associated with Drug Resistance in Mycobacterium tuberculosis Strains
Authors: Ritter C. , Lucke K. , Sirgel F. A. , Warren R. W. , van Helden P. D. , Böttger E. C. , Bloemberg G. V.
Published: January 2014

The rapid accurate detection of drug resistance mutations in
Mycobacterium tuberculosis
is essential for optimizing the treatment of tuberculosis and limiting the emergence and spread of drug-resistant strains. The TB Resistance line probe assay from Autoimmun Diagnostika GmbH (AID) (Strassburg, Germany) was designed to detect the most prevalent mutations that confer resistance to isoniazid, rifampin, streptomycin, amikacin, capreomycin, fluoroquinolones, and ethambutol. This assay detected resistance mutations in clinical
M. tuberculosis
isolates from areas with low and high levels of endemicity (Switzerland,
n
= 104; South Africa,
n
= 52) and in selected
Mycobacterium bovis
BCG 1721 mutant strains (
n
= 5) with 100% accuracy. Subsequently, the line probe assay was shown to be capable of rapid genetic assessment of drug resistance in MGIT broth cultures, the results of which were in 100% agreement with those of DNA sequencing and phenotypic drug susceptibility testing. Finally, the line probe assay was assessed for direct screening of smear-positive clinical specimens. Screening of 98 clinical specimens demonstrated that the test gave interpretable results for >95% of them. Antibiotic resistance mutations detected in the clinical samples were confirmed by DNA sequencing. We conclude that the AID TB Resistance line probe assay is an accurate tool for the rapid detection of resistance mutations in cultured isolates and in smear-positive clinical specimens.
Rapid Resistome Fingerprinting and Clonal Lineage Profiling of Carbapenem-Resistant Klebsiella pneumoniae Isolates by Targeted Next-Generation Sequencing
Authors: Arena Fabio , Rolfe P. Alexander , Doran Graeme , Conte Viola , Gruszka Sarah , Clarke Thomas , Adesokan Yemi , Giani Tommaso , Rossolini Gian Maria
Published: January 2014

Thirty-two carbapenem-resistant
Klebsiella pneumoniae
isolates, representative of different resistance mechanisms and clonal lineages, were analyzed with the Pathogenica HAI BioDetection system, based on targeted next-generation sequencing (NGS) technology. With most strains, the system simultaneously yielded comprehensive information on relevant β-lactam resistance determinants and accurate discrimination of clonal lineages, in a shorter time frame and in a less labor-intensive manner than currently available methods for molecular epidemiology analysis. Results supported the usefulness of targeted NGS-based technologies for similar applications.
Superinfection Exclusion in Alphabaculovirus Infections Is Concomitant with Actin Reorganization
Authors: Beperet Inés , Irons Sarah L. , Simón Oihane , King Linda A. , Williams Trevor , Possee Robert D. , López-Ferber Miguel , Caballero Primitivo
Published: January 2014

Superinfection exclusion is the ability of an established virus to interfere with a second virus infection. This effect was studiedin vitroduring lepidopteran-specific nucleopolyhedrovirus (genusAlphabaculovirus, familyBaculoviridae) infection. Homologous interference was detected in Sf9 cells sequentially infected with two genotypes ofAutographa californicamultiple nucleopolyhedrovirus (AcMNPV), each one expressing a different fluorescent protein. This was a progressive process in which a sharp decrease in the signs of infection caused by the second virus was observed, affecting not only the number of coinfected cells observed, but also the level of protein expression due to the second virus infection. Superinfection exclusion was concurrent with reorganization of cytoplasmic actin to F-actin in the nucleus, followed by budded virus production (16 to 20 h postinfection). Disruption of actin filaments by cell treatment with cytochalasin D resulted in a successful second infection. Protection against heterologous nucleopolyhedrovirus infection was also demonstrated, as productive infection of Sf9 cells bySpodoptera frugiperdanucleopolyhedrovirus (SfMNPV) was inhibited by prior infection with AcMNPV, and vice versa. Finally, coinfected cells were observed following inoculation with mixtures of these two phylogenetically distant nucleopolyhedroviruses—AcMNPV and SfMNPV—but at a frequency lower than predicted, suggesting interspecific virus interference during infection or replication. The temporal window of infection is likely necessary to maintain genotypic diversity that favors virus survival but also permits dual infection by heterospecific alphabaculoviruses.

IMPORTANCEInfection of a cell by more than one virus particle implies sharing of cell resources. We show that multiple infection, by closely related or distantly related baculoviruses, is possible only during a brief window of time that allows additional virus particles to enter an infected cell over a period of ca. 16 h but then blocks multiple infections as newly generated virus particles begin to leave the infected cell. This temporal window has two important consequences. First, it allows multiple genotypes to almost simultaneously infect cells within the host, thus generating genetically diverse virus particles for transmission. Second, it provides a mechanism by which different viruses replicating in the same cell nucleus can exchange genetic material, so that the progeny viruses may be a mosaic of genes from each of the parental viruses. This opens a completely new avenue of research into the evolution of these insect pathogens.
Insights into the Structure and Assembly of the Bacteriophage ϕ29 Double-Stranded DNA Packaging Motor
Authors: Cao Sheng , Saha Mitul , Zhao Wei , Jardine Paul J. , Zhang Wei , Grimes Shelley , Morais Marc C.
Published: January 2014

The tailed double-stranded DNA (dsDNA) bacteriophage ϕ29 packages its 19.3-kbp genome into a preassembled procapsid structure by using a transiently assembled phage-encoded molecular motor. This process is remarkable considering that compaction of DNA to near-crystalline densities within the confined space of the capsid requires that the packaging motor work against significant entropic, enthalpic, and DNA-bending energies. The motor consists of three phage-encoded components: the dodecameric connector protein gp10, an oligomeric RNA molecule known as the prohead RNA (pRNA), and the homomeric ring ATPase gp16. Although atomic resolution structures of the connector and different pRNA subdomains have been determined, the mechanism of self-assembly and the resulting stoichiometry of the various motor components on the phage capsid have been the subject of considerable controversy. Here a subnanometer asymmetric cryoelectron microscopy (cryo-EM) reconstruction of a connector-pRNA complex at a unique vertex of the procapsid conclusively demonstrates the pentameric symmetry of the pRNA and illuminates the relative arrangement of the connector and the pRNA. Additionally, a combination of biochemical and cryo-EM analyses of motor assembly intermediates suggests a sequence of molecular events that constitute the pathway by which the motor assembles on the head, thereby reconciling conflicting data regarding pRNA assembly and stoichiometry. Taken together, these data provide new insight into the assembly, structure, and mechanism of a complex molecular machine.

IMPORTANCE
Viruses consist of a protein shell, or capsid, that protects and surrounds their genetic material. Thus, genome encapsidation is a fundamental and essential step in the life cycle of any virus. In dsDNA viruses, powerful molecular motors essentially pump the viral DNA into a preformed protein shell. This article describes how a viral dsDNA packaging motor self-assembles on the viral capsid and provides insight into its mechanism of action.
Pregnancy as a risk factor for undertreatment after bariatric surgery
Authors: Jacquemyn Yves , Meesters Johanna
Published: January 2014

A pregnant woman presented at the emergency department with severe nausea and vomiting at 20 weeks of gestational age; she was known with gastric banding. Advanced imaging studies were avoided of fear to harm the fetus. The patient continued to vomit and at 23 weeks intrauterine fetal death was noted. The symptoms did not resolve after delivery and CT scan demonstrated slippage of the gastric band over the pylorus resulting in a high digestive obstruction as the cause of hyperemesis and finally resulting necrosis of the vasa brevia. The gastric band was laparoscopically removed along with the necrotic tissue. Avoidance of radiological and endoscopic investigations of fear to harm the pregnancy resulted in complications and possibly in fetal death.
Stereodynamics investigation of F + HO → HF + O(1D) on the ground singlet potential energy surface by means of the quasi-classical trajectory method
Authors: Zhao Dan , He Xiaohu , Guo Wei
Published: January 2014

The stereodynamics calculation of F + HO → HF + O(1D) was carried out using the quasi-classical trajectory method on the 11A′ potential energy surface provided by Gomez-Carrasco et al. (Chem. Phys. Lett. 2007, 435, 188). The effect of the collision energy, isotopic substitution, and different initial ro-vibrational states on the reaction is discussed. It is found that for the initial ground state of HO (v = 0, j = 0), the degree of the forward scattering and the product polarizations remarkably change as the collision energy varies. Isotopic effect leads to the increase of alignment and decrease of orientation of product rotational angular momentum. Moreover, the P(θr) distribution and P(φr) distribution change noticeably by varying the initial vibrational number. The initial vibrational excitation plays a more important role in the enhancement of alignment and orientation distribution of j′ for the title reaction. Although the influence of the initial rotational excitation effect on the aligned and oriented distribution of product is not stronger than that of the initial vibrational excitation effect, the initial rotational excitation makes the alignment of the product rotational angular momentum decrease to some extent. The probabilities show that the reactivity of the title reaction strongly depends on the initial vibrational state.
ON MINIMIZATION OF A NON-CONVEX FUNCTIONAL IN VARIABLE EXPONENT SPACES
Authors: CHACÓN GERARDO R. , COLUCCI RENATO , RAFEIRO HUMBERTO , VARGAS ANDRÉS
Published: January 2014

We study the existence of minimizers of a regularized non-convex functional in the context of variable exponent Sobolev spaces by application of the direct method in the calculus of variations. The results are new even in the framework of classical Lebesgue spaces.
CLASSIFICATION DYNAMICS OF TWO-DIMENSIONAL CHAINS OF EVOLUTION ALGEBRAS
Authors: MURODOV SH. N.
Published: January 2014

Recently by Casas et al. a notion of chain of evolution algebras (CEAs) is introduced. This chain is a dynamical system the state of which at each given time is an evolution algebra. It is known 25 distinct classes of chains of two-dimensional evolution algebras. In our previous paper we gave the classification of two-dimensional real evolution algebras. This classification contains seven (pairwise non-isomorphic) such algebras. For each known CEA we study its dynamics to be an element of a given class.
FUZZY CONIFOLD $Y_F^6$ AND MONOPOLES ON $S_F^2\times S_F^2$
Authors: ACHARYYA NIRMALENDU , VAIDYA SACHINDEO
Published: January 2014

In this paper, we construct the fuzzy (finite-dimensional) analogs of the conifold Y6 and its base X5. We show that fuzzy X5 is (the analog of) a principal U(1) bundle over fuzzy spheres [Formula: see text] and explicitly construct the associated monopole bundles. In particular, our construction provides an explicit discretization of the spaces Tκ, κ and Tκ, 0.
QUANTUM WALKS ON SIERPINSKI GASKETS
Authors: LARA PEDRO CARLOS S. , PORTUGAL RENATO , BOETTCHER STEFAN
Published: January 2014

We analyze discrete-time quantum walks on Sierpinski gaskets using a flip-flop shift operator with the Grover coin. We obtain the scaling of two important physical quantities: The mean-square displacement, and the mixing time as function of the number of points. The Sierpinski gasket is a fractal that lacks translational invariance and the results differ from those described in the literature for ordinary lattices. We find that the diffusion scaling depends on the initial location. Averaged over all initial locations, our simulation obtain an exponent very similar to the classical diffusion.
PARAMETRIC RESONANCE OF WOVEN FIBER LAMINATED COMPOSITE PLATES IN ADVERSE HYGROTHERMAL ENVIRONMENT
Authors: RATH M. K. , SAHU S. K.
Published: January 2014

The present study deals with the parametric instability of woven fiber laminated composite plates subjected to periodic dynamic loadings in adverse hygrothermal environment. The effects of various parameters like increase in number of layers and lamination angle of simply supported composite plates at elevated temperatures and moisture concentrations on the principal instability regions are investigated using finite element method. The effects of transverse shear deformation and rotary inertia, is used to study the anti-symmetric angle-ply square plates. The results show that instability of woven fiber laminated composite plates occurs for different parameters with increase in adverse temperature and moisture environment.
FTMP-BASED MODELING AND SIMULATION OF MAGNESIUM
Authors: KAJIWARA NAOKI , IMIYA KAZUHIRO , HASEBE TADASHI
Published: January 2014

The present study proposes a constitutive model for deformation twinning which takes into account the twin degrees of freedom via incompatibility tensor model based on Field Theory of Multiscale Plasticity (FTMP). The model is introduced in the hardening law in the FTMP-based crystalline plasticity framework, which is further implemented into a finite element code. Deformation analyses are made for pure single crystal magnesium with HCP structure, and the descriptive capabilities of the proposed model are confirmed based on critical comparisons with experimental data under plain–strain compression in multiple orientations, available in the literature. The simulated results are demonstrated to successfully reproduce the unique stress–strain responses induced by twinning. The evolution of the relative activities of the various slips, and twin mechanisms for each orientation are extensively examined.
Protein kinase G increases antioxidant function in lung microvascular endothelial cells by inhibiting the c-Abl tyrosine kinase
Authors: Stephens R. Scott , Servinsky Laura E. , Rentsendorj Otgonchimeg , Kolb Todd M. , Pfeifer Alexander , Pearse David B.
Published: January 2014

Oxidant injury contributes to acute lung injury (ALI). We previously reported that activation of protein kinase GI (PKGI) posttranscriptionally increased the key antioxidant enzymes catalase and glutathione peroxidase 1 (Gpx-1) and attenuated oxidant-induced cytotoxicity in mouse lung microvascular endothelial cells (MLMVEC). The present studies tested the hypothesis that the antioxidant effect of PKGI is mediated via inhibition of the c-Abl tyrosine kinase. We found that activation of PKGI with the cGMP analog 8pCPT-cGMP inhibited c-Abl activity and decreased c-Abl expression in wild-type but not PKGI−/− MLMVEC. Treatment of wild-type MLMVEC with atrial natriuretic peptide also inhibited c-Abl activation. Moreover, treatment of MLMVEC with the c-Abl inhibitor imatinib increased catalase and GPx-1 protein in a posttranscriptional fashion. In imatinib-treated MLMVEC, there was no additional effect of 8pCPT-cGMP on catalase or GPx-1. The imatinib-induced increase in antioxidant proteins was associated with an increase in extracellular H2O2 scavenging by MLMVEC, attenuation of oxidant-induced endothelial barrier dysfunction, and prevention of oxidant-induced endothelial cell death. Finally, in the isolated perfused lung, imatinib prevented oxidant-induced endothelial toxicity. We conclude that cGMP, through activation of PKGI, inhibits c-Abl, leading to increased key antioxidant enzymes and resistance to lung endothelial oxidant injury. Inhibition of c-Abl by active PKGI may be the downstream mechanism underlying PKGI-mediated antioxidant signaling. Tyrosine kinase inhibitors may represent a novel therapeutic approach in oxidant-induced ALI.