bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of a β-lactamase that contributes to intrinsic β-lactam resistance inClostridioides difficile
Authors: Sandhu Brindar K. , Edwards Adrianne N. , Anderson Sarah E. , Woods Emily C. , McBride Shonna M.
Published: May 2019

Clostrididioides difficilecauses severe antibiotic-associated diarrhea and colitis.C. difficileis an anaerobic, Gram-positive spore former that is highly resistant to β-lactams, the most commonly prescribed antibiotics. The resistance ofC. difficileto β-lactam antibiotics allows the pathogen to replicate and cause disease in antibiotic-treated patients. However, the mechanisms of β-lactam resistance inC. difficileare not fully understood. Our data reinforce prior evidence thatC. difficileproduces a β-lactamase, which is a common β-lactam resistance mechanism found in other bacterial species. We identified an operon encoding a lipoprotein of unknown function and a β-lactamase that was greatly induced in response to several classes of β-lactam antibiotics. An in-frame deletion of the operon abolished β-lactamase activity inC. difficilestrain 630Δermand resulted in decreased resistance to the β-lactam ampicillin. We found that the activity of this β-lactamase, herein named BlaD, is dependent upon the redox state of the enzyme. In addition, we observed that transport of BlaD out of the cytosol and to the cell surface is facilitated by an N-terminal signal sequence. Our data demonstrate that a co-transcribed lipoprotein, BlaX, aids in BlaD activity. Further, we identified a conserved BlaRI regulatory system and demonstrated via insertional disruption that BlaRI controls transcription of theblaXDoperon in response to β-lactams. These results provide support for the function of a β-lactamase inC. difficileantibiotic resistance, and reveal the unique roles of a co-regulated lipoprotein and reducing environment in β-lactamase activity.

IMPORTANCE

Clostridioides difficileis an anaerobic, gastrointestinal human pathogen. One of the highest risk factors for contractingC. difficileinfection is antibiotic treatment, which causes microbiome dysbiosis.C. difficileis resistant to β-lactam antibiotics, the most commonly prescribed class of antibiotics.C. difficileproduces a recently discovered β-lactamase, which cleaves and inactivates numerous β-lactams. In this study, we report the contribution of this anaerobic β-lactamase to ampicillin resistance inC. difficile, as well as the transcriptional regulation of the gene,blaD, by a BlaRI system. In addition, our data demonstrate co-transcription ofblaDwithblaX, which encodes a membrane protein of previously unknown function. Furthermore, we provide evidence that BlaX enhances β-lactamase activity in a portion ofC. difficilestrains. This study demonstrates a novel interaction between a β-lactamase and a membrane protein in a Gram-positive pathogen, and due to the anaerobic nature of the β-lactamase activity, suggests that more β-lactamases are yet to be identified in other anaerobes.
Large Scale-Free Network Organization is Likely Key for Biofilm Phase Transition
Authors: Selvarajoo Kumar
Published: May 2019

Non-linear Kuramoto model has been used to study synchronized or sync behavior in numerous fields, however, its application in biology is scare. Here, I introduce the basic model and provide examples where large scale small-world or scale-free networks are crucial for spontaneous sync even for low coupling strength. This information was next checked for relevance in living systems where it is now well-known that biological networks are scale-free. Our recent transcriptome-wide data analysis of Saccharomyces cerevisiae biofilm showed that low to middle expressed genes are key for scale invariance in biology. Together, the current data indicate that biological network connectivity structure with low coupling strength, or expression levels, is sufficient for sync behavior. For biofilm regulation, it may, therefore, be necessary to investigate large scale low expression genes rather than small scale high expression genes.
The photoactive site modulates current rectification and channel closing in the natural anion channelrhodopsin GtACR1
Authors: Sineshchekov Oleg A. , Govorunova Elena G. , Li Hai , Wang Xin , Spudich John L.
Published: May 2019

The crystal structure of GtACR1 from Guillardia theta revealed an intramolecular tunnel predicted to expand to form the anion-conducting channel upon photoactivation (Li et al. 2019). The location of the retinylidene photoactive site within the tunnel raised the question of whether, in addition to triggering channel opening by photoisomerization, the site also participates in later channel processes. Here we demonstrate the involvement of the photoactive site in chloride conductance and channel closing. Electrostatic perturbation of the photoactive retinylidene Schiff base region by glutamate substitutions alters the rectification of the photocurrent as well as channel closing kinetics. Substitutions on opposite sides of the photoactive site causes opposite changes, with channel closing kinetically correlated with Schiff base deprotonation, and the extent of these effects closely correlate with distance of the introduced glutamyl residue from the photoactive site.
Comparison of silhouette-based reallocation methods for vegetation classification
Authors: Lengyel Attila , Roberts David W. , Botta-Dukát Zoltán
Published: May 2019

Aims

To introduce REMOS, a new iterative reallocation method (with two variants) for vegetation classification, and to compare its performance with OPTSIL. We test (1) how effectively REMOS and OPTSIL maximize mean silhouette width and minimize the number of negative silhouette widths when run on classifications with different structure; (2) how these three methods differ in runtime with different sample sizes; and (3) if classifications by the three reallocation methods differ in the number of diagnostic species, a surrogate for interpretability.

Study area

Simulation; example data sets from grasslands in Hungary and forests in Wyoming and Utah, USA.

Methods

We classified random subsets of simulated data with the flexible-beta algorithm for different values of beta. These classifications were subsequently optimized by REMOS and OPTSIL and compared for mean silhouette widths and proportion of negative silhouette widths. Then, we classified three vegetation data sets of different sizes from two to ten clusters, optimized them with the reallocation methods, and compared their runtimes, mean silhouette widths, numbers of negative silhouette widths, and the number of diagnostic species.

Results

In terms of mean silhouette width, OPTSIL performed the best when the initial classifications already had high mean silhouette width. REMOS algorithms had slightly lower mean silhouette width than what was maximally achievable with OPTSIL but their efficiency was consistent across different initial classifications; thus REMOS was significantly superior to OPTSIL when the initial classification had low mean silhouette width. REMOS resulted in zero or a negligible number of negative silhouette widths across all classifications. OPTSIL performed similarly when the initial classification was effective but could not reach as low proportion of misclassified objects when the initial classification was inefficient. REMOS algorithms were typically more than an order of magnitude faster to calculate than OPTSIL. There was no clear difference between REMOS and OPTSIL in the number of diagnostic species.

Conclusions

REMOS algorithms may be preferable to OPTSIL when (1) the primary objective is to reduce or eliminate negative silhouette widths in a classification, (2) the initial classification has low mean silhouette width, or (3) when the time efficiency of the algorithm is important because of the size of the data set or the high number of clusters.
Co-regulation and functional cooperativity of FOXM1 and RHNO1 bidirectional genes in ovarian cancer
Authors: Barger Carter J , Branick Connor , Chee Linda , Albahrani Mustafa , Klinkebiel David , Drapkin Ronny , Odunsi Kunle , Zou Lee , Karpf Adam R.
Published: May 2019

We report that the oncogenic transcription factorFOXM1is arranged in a head-to-head configuration withRHNO1, a gene involved in the ATR/CHK1-dependent DNA replication stress (DRS) response.FOXM1andRHNO1are both amplified and upregulated in high-grade serous ovarian cancer (HGSC).FOXM1andRHNO1expression are closely associated in normal and cancer tissues, including single cells, and a bidirectional promoter (F/R-BDP) mediates balanced expression. Targeting of FOXM1 and RHNO1 in HGSC cells using shRNA, CRISPR mutagenesis, or CRISPR interference directed to the F/R-BDP reduced DNA homologous recombination repair (HR) capacity, increased DNA damage, reduced clonogenic survival, and sensitized HGSC cells to the poly-ADP ribosylase inhibitor (PARPi) olaparib. Thus, there is functional cooperativity between FOXM1 and RHNO1 in cancer cells, and combinatorial targeting of this bidirectional gene pair may be a novel cancer therapeutic strategy. More broadly, our data provide evidence that bidirectional gene units function in human cancer.
“Health literacy assessment of primary care patients in Low and Middle Income Countries”
Authors: Pasha F. , Dreshaj D. , Ismaili A. , Sopjani I. , Brooke J. , Dreshaj Sh.
Published: May 2019

Aim

To explore health literacy levels of primary care patients, and associations with demographic variables, frequency of visits, hospitalization rates, and self-perception of health.

Background

Health literacy is the ability to obtain, read, understand and apply healthcare information to inform decision-making to commence or adhere to treatment. The benefits of a population proficient in health literacy include enhanced communication, adherence to treatment, engagement in self-care, and ultimately improved health with financial savings for healthcare providers.

Design

Cross-sectional epidemiological study, reported using STROBE guidelines.

Materials and Methods

Data were collected from patients attending a primary care center in Prishtina, Kosovo from August to September 2018. Data collection included the Short Test of Functional Health Literacy in Adults (S-TOFHLA), gender, age, socioeconomic status, education, self-perception of health, number of visits to the doctor and hospital. Data were analyzed with SPSS software (version 20).

Results

Participants (n=557) ages ranged from 15 to >65 (mean 27.82) years, were female (57.85%), Albanian (97.13%), with a response rate of 92.83%, 79% were health literate, 9% had moderate health literacy, 12% were health illiterate. Four variables determined health literacy, level of education (p < .01), gender (p = .033), hospitalization rates (p < .05), socioeconomic status of unemployed compared to being a student (p<.01).

Conclusions

There remains a need to address health literacy levels in Kosovo, through the development or adaptation of health literacy tools appropriate for this population, which will support and positively impact on patient’s wellbeing. Nurses are the best-placed professionals to implement these tools and support patients with low health literacy.

Relevance to clinical practice

Nurses have a key role in implementing health literacy tools and supporting patients by adapting their communication styles in accordance with each patient’s level of health literacy, which will support adherence to advice, safety and treatment outcomes.

What does this paper contribute to the wider global clinical community?

Health literacy is associated with level of education, gender and socioeconomic status and hospitalization rates of primary care patients.

A focus on health literacy is essential to address the inequalities of health for those with marginal or inadequate health literacy.

Nurses are the best-placed health care professionals to support individuals with low levels of health literacy through interventions, and adapting their communication styles.
Vapour growth, morphology, absolute structure and pyroelectric coefficient ofmeta-nitroaniline single crystals
Authors: Hesterberg Rolf , Bonin Michel , Sommer Martin , Burgener Matthias , Trusch Bernhard , Damjanovic Dragan , Hulliger Jürg
Published: May 2019

The growth speed of (hkl) faces in the vapour phase, the absolute structure obtained by X-ray crystallography, and the value and the sign of the pyroelectric coefficient ofmeta-nitroaniline (mNA) were analysed in detail. Thein situobservation of morphologically well developed faces of several mNA crystals growing in evacuated ampoules reveals no pronounced growth speed anisotropy for polar faces defining the unique axis 2 of themm2 group. Scanning pyroelectric microscopy confirms mono-domain mNA crystals. X-ray measurements in the space groupPca21show that the molecular planes coincide with the {\bar 211} and {\bar 2\bar 1\bar 1} faces, and the nitro groups cover the {201} face in the opposite direction to the crystal tip, characterizing the polar habitus studied here. At room temperature, the sign of the pyroelectric coefficient is positive for a measured effective value of 6.3 µC m−2 K−1, in good agreement with values reported by other authors. From previous elastic and piezoelectric published data, the secondary pyroelectric effect was calculated to be positive and far greater than the effective one, yielding a negative value for the primary pyroelectric coefficient.
Thermally induced transformations of Au@Cu2O core–shell nanoparticles into Au–Cu nanoparticles from temperature-programmed in situ powder X-ray diffraction
Authors: Koch Robert , Li Guangfang , Pandey Shubham , Phillpot Simon , Wang Hui , Misture Scott T.
Published: May 2019

Temperature-programmed in situ X-ray diffraction with whole-powder-pattern modeling is used to investigate the reaction of Au@Cu2O core–shell nanoparticles to form nanocrystalline bimetallic Cu
x
Au1−x
alloys (x = 0, 0.25, 0.5, 0.75, 1.0) in a reducing atmosphere. The mechanisms of the reactions are key to informed design of tailored non-equilibrium nanostructures for catalytic and plasmonic materials. The Au@Cu2O reaction is initiated by reduction of the Cu2O cuprite shell to form nanocrystalline metallic Cu at about 413 K. Alloying begins immediately upon formation of metallic Cu at 413 K, with the nucleation of an Au-rich alloy phase which reaches the nominal Cu content of the overall system stoichiometry by 493 K. All bimetallic alloys form a transient ordered Cu3Au intermetallic compound at intermediate temperatures, with the onset of ordering and subsequent disordering varying by composition. No evidence for an ordered Au3Cu intermetallic is found for any composition. Significant crystal growth in the bimetallic phase is apparent at higher temperatures, with the onset temperature increasing with Cu concentration and initial Cu-shell thickness. The reduction of the cuprite phase is slowed by the presence of the core–shell interface, and crystal growth in the Cu shell is completely suppressed within the alloy systems.
Commercial or educational orientations
Authors: Ho Amaly
Published: May 2019

Purpose

Taught postgraduate (TPg) education is the resource for lifelong learning and continuing education in respond to the demands of a qualified workforce in the digital era. Good TPg governance is crucial for ensuring the quality of student learning outcomes. The purpose of this paper is to discuss the framework of the market-oriented governance model of TPg education in Hong Kong from the aspects of provision, finance and quality assurance. The framework is applied to analyse the pitfalls of TPg students’ learning in curriculum, assessment and management, of which data were collected from an empirical study.

Design/methodology/approach

Based on the grounded theory approach, semi-structured interviews were conducted with 23 TPg students from four universities in Hong Kong at individual or group level to understand their motivation towards further study. The interview protocols were analysed to develop a thematic framework, and a part of it is presented in this paper to discuss the programme factors that caused negative student learning outcomes in the light of the drawbacks of the TPg governance model in Hong Kong.

Findings

A balance between commercial purposes and educational orientations of TPg provision could be sought by adjust the power distribution of the central government and institutions in terms of quality assurance mechanism, and the setting and implementation of general and specific goals of TPg education.

Originality/value

TPg education is an under investigation area. It is an important education sector that provides opportunities for lifelong learning with the purpose of cultivating a skilful workforce. This paper contributes to the development of efficient TPg governance for ensuring the qualities of TPg programmes to benefit the advancement of society in the Hong Kong context.
Inpatient treatment of borderline personality disorder in adults with intellectual disability: reflections on practice
Authors: Iversen Trine Elisabeth , Horndalsveen Kristin , Matre Espen , Henriksen Tine Finstad , Fusche Sarah , Kildahl Arvid Nikolai , Bakken Trine Lise
Published: May 2019

Purpose

There are few publications on personality disorder in adults with intellectual disability (ID), and on borderline personality disorder (BPD) specifically. Publications concerning treatment are sparse, despite the high symptom burden in these patients. This paper aims to discuss these issues.

Design/methodology/approach

Six patients with BPD and ID were recruited from the same inpatient unit. Behaviour problems and mental health symptoms were scored on admission and discharge. Information about treatment, length of stay, etc. was taken from case files.

Findings

Both mental health symptoms measured by the SCL-90-R, and behaviour problems measured by the Aberrant Behaviour Checklist were significantly reduced on discharge. In the active treatment period, the two main aspects of treatment were validation and practicing new solutions when emotional and behavioural problems occur, i.e. skills training.

Research limitations/implications

The limitations related to this study are that the study is conducted in one milieu only. Another limitation is that the patients were admitted over a five-year period, where, some changes were made in the treatment approach.

Practical implications

Inpatient treatment of this patient group seems to be effective if individually adjusted to the patient’s psychopathology, ID and communication style. Close co-operation between the individual therapist and milieu therapists is essential.

Originality/value

There is a need for intervention studies on BPD in ID. This study may be a valuable contribution.
What’s the penalty for using the Square Root Law of inventory centralisation?
Authors: Oeser Gerald
Published: May 2019

Purpose

The square root law (SRL) is a popular model for assessing inventory levels when changing the number of warehouses. Previous empirical research, however, has shown that mostly its underlying assumptions do not hold in practice. This sparks the question how inaccurate the SRL’s results are. The paper aims to discuss this issue.

Design/methodology/approach

In 26 company cases of reducing the number of warehouses, the estimation error of the SRL is analysed irrespective of its underlying assumptions.

Findings

The analysis reveals an average estimation error for total inventory of 27.85 per cent (median=27.84 per cent), but a high variability across the cases. The SRL seems to mostly overestimate inventory savings from centralisation and inventory increases from decentralisation. Managers should only use the SRL if inventory depends on the number of warehouses in their situation, i.e. if they use the economic order or production quantity policy and safety factor approach. Suggestions for coping with the SRL’s estimation error are given.

Research limitations/implications

This paper is based on the 26 cases that could be found in a thorough literature review in the ten most widely spoken languages and that contained or allowed to deduce the necessary information. In order to enable wider generalisations, this sample could be extended.

Originality/value

Most past research has been more theoretical in nature. This research is the first to investigate the SRL’s estimation error using a variety of company cases and how to cope with this error.
“It’s a bit of freedom away from home and cleaning all the time”
Authors: Cudworth Dave
Published: May 2019

Purpose

Much has been written over the past 50 years about the concerns associated with the educational underachievement of Gypsy children in England. This work has usually focussed on ethnicity and mobility as key factors that affect school attendance. However, it is only relatively recently that a concern with gender relations has entered the debate. Therefore, the purpose of this paper is to provide an empirically driven contribution to this fledging area of enquiry.

Design/methodology/approach

This paper draws on semi-structured interview material and a focus group discussion about the educational experiences and aspirations of three mothers and six young women from the community. Further, interview materials were collected from two head teachers with Gypsy children in their schools and two Traveller Education Support Staff.

Findings

This paper finds how educational “public” space is providing a place for girls and young women to think differently and even begin to challenge the gender regimes embedded within the “private” space of their communities.

Originality/value

In line with the idea that space and place are fundamental in formulating gender relations, this paper frames this phenomenon within a socio-spatial context.
Psoriasis is associated with increased risk of bullous pemphigoid: A nationwide population‐based cohort study in Taiwan
Authors: Ho Yi‐Hsin , Hu Hsiao‐Yun , Chang Yun‐Ting , Li Chung‐Pin , Wu Chen‐Yi
Published: May 2019

Psoriasis may coexist with bullous pemphigoid (BP); however, no cohort studies have investigated the relationship between psoriasis and the risk of BP. This study aims to investigate the relationship between psoriasis and the risk of BP in Taiwan. This cohort study consists of 109 777 psoriatic patients and 109 777 matched non‐exposed controls. Psoriatic patients diagnosed between 2002 and 2012 were identified from the Taiwan National Health Insurance Research Database. The age‐, sex‐ and index date‐matched non‐exposed group was selected from the same database. The relationship between psoriasis and the risk of BP was investigated using Cox proportional hazards analyses. Psoriasis was significantly associated with an increased risk of BP (hazard ratio, 3.05; 95% confidence interval, 2.10–4.43; P < 0.001). The mean interval between the diagnoses of psoriasis and BP was 2.86 years, with the highest occurrence in the first year after psoriasis diagnosis, and gradually decreasing with each year of observation. Psoriatic patients with BP were significantly younger than BP patients in the non‐exposed group (71.6 ± 13.9 vs 76.6 ± 7.7 years, respectively; P = 0.030). A higher proportion of patients with coexisting psoriasis and BP received phototherapy (20%). In conclusion, psoriasis was independently associated with a 3.05‐fold increased risk of BP, and psoriatic patients with BP were younger, with over one‐third of BP cases diagnosed in the first year after incident psoriasis. Therefore, clinicians treating patients with psoriasis may be aware of the possibility of the development of BP.
Marketing Integration Decisions, Intermediate Goals and Market Expansion in Horizontal Acquisitions: How Marketing Fit Moderates the Relationships on Intermediate Goals
Authors: Bauer Florian , Rothermel Marcella , Tarba Shlomo Y. , Arslan Ahmad , Uzelac Borislav
Published: May 2019

Despite their enormous importance for value creation, marketing topics are broadly ignored in merger and acquisitions (M&A) research. Even though the internal aspects of M&A processes receive much research attention, marketing‐related integration decisions play an important role in customer retention and market expansion. In this paper, we develop a model that integrates core marketing integration decisions, intermediate goals and market expansion by considering the contingency of marketing fit. The theoretical framework was tested empirically through a sample of 82 horizontal acquisitions made by acquirers from German‐speaking countries. Our results show that there are no universally pertinent integration decisions; rather, there are important trade‐offs that, when aggregated, may explain the insignificant results achieved by commonly accepted success factors. Furthermore, intermediate goals mediate the relationship between integration decisions and market expansion. Implications for management research and practice are also discussed.
An Ethnographic Perspective on Urban Planning in Brazil: Temporality, Diversity and Critical Urban Theory
Authors: Koster Martijn
Published: May 2019

This article provides an ethnographic perspective on urban planning by presenting the creative practices of marginalized slum residents in Recife, Northeast Brazil, who are affected by planners’ decisions. It argues that such a perspective contributes to current critical urban theory in three ways. First, while many studies of urban planning follow the temporality of the timeframe of a particular project (‘project time’), this analysis emphasizes the timeframe of the lives of the affected residents (‘people's time’). Second, it attends to diversity, taking account of the variety of affected residents and the diverse consequences of urban planning on their lives. Third, it shows how urban interventions — similar to marriage, divorce, the birth of children and the death of loved ones — are high‐impact life events for the urban poor. Finally, the article assesses the engagement between ethnography and critical urban theory and argues in favour of ‘grounding’ the latter better in the analysis of actual practices and experiences.
Structural Evolution of Chepaizi Uplift and its Control on Stratigraphic Deposition in the Western Junggar Basin, China
Authors: NI Minjie , CHEN Shi , LIU Zichao , SHANG Fengkai , QI Jiafu , WANG Lishuang
Published: May 2019

Geological mapping, interpreted cross sections, structural analyses and residual thickness maps were used to characterize the evolution of stress setting, structure and stratigraphic distribution of the Chepaizi Uplift, which is a NW‐SE trending structure located in the Western Junggar Basin. The NS‐trending faults show an important transpressional phase during the Late Permian, as demonstrated by tectonic stress field and stratigraphic thickness variations. A major compressional thrusting and strike‐slip phase during the Late Jurassic created a series of NW‐SE faults that originated by the large‐scale uplift event in the Northern Tianshan. Faults were reactivated as thrust and dextral strike‐slip faults. In addition, the angular unconformity observed between Jurassic and Cretaceous provide evidence of this tectonic event. Lots of normal faults indicate that the area records southward tilting and regional derived extensional stress that took place during the Neogene. Before that, thick Early Cenozoic strata are widely deposited. The balanced cross‐section highlights the evolution of stress setting and stratigraphic distribution of the Chepaizi Uplift.
Full‐Sized Pore Structure and Fractal Characteristics of Marine‐Continental Transitional Shale: A Case Study in Qinshui Basin, North China
Authors: YIN Liangliang , GUO Shaobin
Published: May 2019

Based on 10 shale samples collected from 4 wells in Qinshui Basin, we investigate the full‐sized pore structure and fractal characteristics of Marine‐Continental transitional shale by performing organic geochemistry, mineralogical composition, Nitrogen gas adsorption (N2 adsorption) and Nuclear Magnetic Resonance (NMR) measurements and fractal analysis. Results show that the TOC content of the shale samples is relatively high, with an average value of 2.44wt%, and the thermal evolution is during the mature‐over mature stage. The NMR T2 spectrum can be used to characterize the full‐sized pore structure characteristics of shale. By combining N2 adsorption pore structure parameters and NMR T2 spectrums, the surface relaxivity of samples are calculated to be between 1.7877 um/s and 5.2272 um/s. On this basis, the T2 spectrums are converted to full‐sized pore volume and surface area distribution curves. The statistics show that the pore volume is mainly provided by mesopore, followed by micropore, and the average percentages are 65.04% and 30.83% respectively; the surface area is mainly provided by micropore, followed by mesopore, and the average percentages are 60.8004% and 39.137% respectively; macropore contributes little to pore volume and surface area. The pore structure characteristics of shale have no relationship with TOC, but strong relationships with clay minerals content. NMR fractal dimensions Dmicro and Dmeso have strong positive relationships with the N2 adsorption fractal dimensions D1 and D2 respectively, indicating that Dmicro can be used to characterize the fractal characteristics of pore surface, and Dmeso can be used to characterize the fractal characteristics of pore structure. The shale surface relaxivity is controlled by multiple factors. The increasing of clay mineral content, pore surface area, pore surface fractal dimension and the decreasing of average pore size, will all lead to the decreasing of shale surface relaxivity.
Discovery and Analysis of Shale Gas in a Carboniferous Reservoir and its Enrichment Characteristics in the Northern Nanpanjiang Depression, Guizhou Province, China
Authors: LU Shufan , LUO Xiangjian , DU Shengjiang , HE Ben , FU Hongbin , LIU Kuiyong
Published: May 2019

Shale gas resources are considered to be extremely abundant in southern China, which has dedicated considerable attention to shale gas exploration in recent years. Exploration of shale gas has considerably progressed and several breakthroughs have been made in China. However, shale gas explorations are still scarce. Summary and detailed analysis studies on black shale reservoirs are still to be performed for many areas. This lack of information slows the progress of shale gas explorations and results in low quantities of stored black shale. The Carboniferous Dawuba Formation, which is widely distributed and considerably thick, is one of the black shale formations targeted for shale gas exploration in southern China in the recent years. The acquisition and analysis of total organic carbon, vitrinite reflectance, types of organic matter, mineral composition, porosity, and permeability are basic but important processes. In addition, we analyzed the microscopic pores present in the shale. This study also showesd the good gas content of the Dawuba Formation, as well as the geological factors affecting its gas content and other characteristics. To understand the prospect of exploration, we compared this with other shale reservoirs which have been already successfully explored for gas. Our comparison showesd that those shale reservoirs have similar but not identical geological characteristics.
Pore Structure Heterogeneity of the Xiamaling Formation Shale Gas Reservoir in the Yanshan Area of China: Evaluation of Geological Controlling Factors
Authors: LI Xueyuan , CHEN Shangbin , WANG Xiaoqi , ZHU Yanming , CHANG Minghua , UWAMAHORO Clementine
Published: May 2019

Micro‐heterogeneity is an integral parameter of the pore structure of shale gas reservoir and it forms an essential basis for setting and adjusting development parameters. In this study, scanning electron microscopy, high‐pressure mercury intrusion and low‐temperature nitrogen adsorption experiments were used to qualitatively and quantitatively characterize the pore structure of black shale from the third member of the Xiamaling Formation in the Yanshan area. The pore heterogeneity was studied using fractal theory, and the controlling factors of pore development and heterogeneity were evaluated in combination with geochemical parameters, mineral composition, and geological evolution history. The results show that the pore structure of the reservoir was intricate and complicated. Moreover, various types of micro‐nano scale pores such as dissolution pores, intergranular pores, interlayer pores, and micro‐cracks are well developed in member 3 of the Xiamaling Formation. The average porosity was found to be 6.30%, and the mean value of the average pore size was 4.78 nm. Micropores and transition pores provided most of the storage space. Pore development was significantly affected by the region and was mainly related to the total organic carbon content, vitrinite reflectance and mineral composition. The fractal dimension, which characterizes the heterogeneity, is 2.66 on average, indicating that the pore structure is highly heterogeneous. Fractal dimension is positively correlated with maturity and clay mineral content, while it is negatively correlated with brittle mineral content and average pore size. These results indicate that pore heterogeneity is closely related to thermal history and material composition. Combined with the geological background of this area, it was found that the pore heterogeneity was mainly controlled by the Jurassic magmatism. The more intense the magma intrusion, the stronger the pore heterogeneity. The pore structure and its heterogeneity characteristics present today are a general reflection of the superimposed geological processes of sedimentary‐diagenetic‐late transformation. The influence of magmatic intrusion on the reservoir is the main geological factor that should be considered for detailed evaluation of the Xiamaling Formation shale gas reservoir in the Yanshan area.
Origin and Petrogenetic Implications of Spessartine Garnet in Highly‐Fractionated Granite from the Central Eastern Desert of Egypt
Authors: SAMI Mabrouk , NTAFLOS Theodoros , MOHAMED Haroun A. , FARAHAT Esam S. , HAUZENBERGER Christoph , MAHDY Nasser M. , ABDELFADIL Khaled M. , FATHY Douaa
Published: May 2019

A highly‐fractionated garnet‐bearing muscovite granite represents the marginal granitic facies of the Abu‐Diab multiphase pluton in the Central Eastern Desert of Egypt. New electron microprobe analyses (EMPA) and laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) data from garnets are reported, in order to constrain their origin and genesis. Garnet in the Abu‐Diab host granite is euhedral to subhedral, generally homogeneous and, in rare cases, it shows weak zonation. The garnet contains appreciable amounts of MnO and FeO, with lesser amounts of MgO and CaO, yielding an end‐member formula of Sps61–72Alm25–35Prp1–4Adr0–1. Moreover, it is depleted in large ion lithophile elements (LILE) with lower values of Ba, Nb and Sr relative to the primitive mantle. Additionally, it contains high concentrations of HREE and Y and their REE pattern shows strong negative Eu anomalies. The garnet was crystallized under relatively low temperature (646°C–591°C) and pressure (< 3 kbar) conditions. The textural and chemical features indicate that the garnet is magmatic in origin and is chemically similar to that from highly‐fractionated A‐type granite. It was probably formed at the expense of biotite in a highly‐evolved MnO‐rich magma and/or by hydroxyl complexing of Mn during the ascending fluid phases.
Pore Structure Characterization of Clay Minerals in the Lower Karamay Formation Conglomerate Reservoir in the Junggar Basin and its Impact on Hydrocarbon Storage and Seepage
Authors: ABITKAZY Taskyn , DU Shuheng , XU Feng , SHI Yongmin
Published: May 2019

The micro‐nano pore structure of conglomerate in the Lower Karamay Formation of the Xinjiang Oilfield, Junggar Basin, northern China is characterized to predict its impact on fluid reserves and seepage. Authigenic clay minerals are mainly kaolinite (67%), followed by an illite/smectite mixed layer (18%), illite (10%), and chlorite (5%). For kaolinite, pore throats between 0–200 nm are dominant, accounting for 90% of the total pore throats. For illite/smectite mixed layer, pore throats also between 0–200 nm account for nearly 80%, while pore throats between 200‐500 nm only account for 15%. For illite, pore throats below 100 nm account for about 80%, while pore throats in the range of 100–500 nm only account for 20%. For chlorite, most throats are below 200 nm. The pore roundness of illite is the highest, while the pore roundness of chlorite is relatively lower. The lower limits of the dynamic and static pore throat radii are 42.128 nm and 72.42 nm, respectively. The theoretical contribution rates of the illite/smectite mixed layer, kaolinite, illite and chlorite to storage/seepage are 60%/45.86%, 52.72%/38.18%, 37.07%/28.78% and 32.97%/26.3%, respectively. Therefore, the contribution rates of clay minerals in the study area are as follows: illite/smectite mixed layer, kaolinite, illite and chlorite.
Vasoactive intestinal peptide‐induced tolerogenic dendritic cells attenuated arthritis in experimental collagen‐induced arthritic mice
Authors: Wu Huaxiang , Shen Jingfang , Liu Lei , Lu Xiaoyong , Xue Jing
Published: May 2019

Aim

Cumulative evidence has revealed that tolerogenic dendritic cells (tolDC) could relieve inflammation reactions in various autoimmune diseases. This study investigated the potential therapeutic application of vasoactive intestinal peptide (VIP)‐induced tolDC (VIP‐DC) on arthritis using collagen‐induced arthritis (CIA) mice.

Methods

Bone marrow cells were differentiated into dendritic cells (DC) using granulocyte macrophage colony‐stimulating factor and interleukin (IL)‐4. tolDC were induced by either VIP or Bay 11‐7082 in vitro. Immunophenotypes and cytokine production of VIP‐DC and Bay‐DC were detected by fluorescence‐activated cell sorting and enzyme‐linked immunosorbent assay, respectively. Bay‐DC, VIP‐DC and untreated DC were ip administrated to CIA mice on day 40 when arthritis was onset. The treatment effects on arthritic and pathological changes, including synovial hyperplasia, pannus formation, inflammation and bone erosion, were assessed.

Results

VIP‐DC (40 ng/mL) and Bay‐DC (0.5 µg/mL) had a lower level of major histocompatibility complex II, CD40 and CD86 expression, reduced γ‐interferon and increased IL‐4 production (P < 0.05 or 0.01), compared with untreated DC. The administration of VIP‐DC and Bay‐DC decreased the arthritis score clinically at the end of the therapy. Pathological assessments showed that bone erosion and inflammation were alleviated in the VIP‐DC group compared with those in the untreated DC group (P < 0.05 and P < 0.01, respectively).

Conclusion

VIP‐DC showed reduced immunogenicity and enhanced anti‐inflammatory cytokine production. Both VIP‐DC and Bay‐DC could ameliorate arthritis in CIA mice clinically. VIP‐DC were not inferior to Bay 11‐7082‐induced tolDC but may exert a better preventive effect on bone destruction.
Forecast Accuracy and Consistent Preferences for the Timing of Information Arrival
Authors: Hofmann Christian , Rothenberg Naomi R.
Published: May 2019

We study a principal's choice of whether to produce an imperfect forecast about a firm's outcome either before or after an agent's effort choice. The early forecast affects the agent's effort choice, which means the forecast can also be used to infer information about the effect of the agent's effort on outcome. The late forecast is more accurate because, by working hard, the agent also learns about productivity, implying that the late forecast has an additional performance measurement role. With verifiable information, the principal prefers a late forecast when the agent's effect on the accuracy of the forecast is either large or small. The agent has consistent preferences when the agent's effect on the accuracy of the late forecast is not too large. With unverifiable information, the agent's information rents imply that the principal cannot use either forecast as a performance measure. Thus, the accuracy of the late forecast has no effect on the principal's preference. However, if the accuracy of the early forecast is low and its decision‐making function is diminished, the principal prefers a late signal.
It Goes without Saying: The Effects of Intrinsic Motivational Orientation, Leadership Emphasis of Intrinsic Goals, and Audit Issue Ambiguity on Speaking Up
Authors: Kadous Kathryn , Proell Chad A. , Rich Jay , Zhou Yuepin (Daniel)
Published: May 2019

Regulation requires auditors to raise significant audit issues and concerns to the attention of audit engagement leadership and requires leadership to encourage such communication. This research demonstrates, using an experiment and a survey, that audit team members' willingness to speak up about such issues is associated with their intrinsic motivational orientation. Based on this result, we test whether audit leadership can leverage this relationship to increase speaking up, particularly when audit issues are more ambiguous, by emphasizing intrinsic goals. Results across three additional experiments indicate that auditors whose leaders emphasize intrinsic goals, whether directly or through tone at the top and firm culture, are more likely to speak up than are other auditors. We also find that auditors are more likely to speak up when an audit issue is less versus more ambiguous. We conclude that leadership can fulfill their obligation to encourage upward communication by emphasizing intrinsic versus extrinsic goals, regardless of the level of ambiguity surrounding the audit issue.
Molecular footprint of Medawar’s mutation accumulation process in mammalian aging
Authors: Turan Zeliha Gözde , Parvizi Poorya , Dönertaş Handan Melike , Tung Jenny , Khaitovich Philipp , Somel Mehmet
Published: May 2019

Medawar's mutation accumulation hypothesis explains aging by the declining force of natural selection with age: Slightly deleterious germline mutations expressed in old age can drift to fixation and thereby lead to aging‐related phenotypes. Although widely cited, empirical evidence for this hypothesis has remained limited. Here, we test one of its predictions that genes relatively highly expressed in old adults should be under weaker purifying selection than genes relatively highly expressed in young adults. Combining 66 transcriptome datasets (including 16 tissues from five mammalian species) with sequence conservation estimates across mammals, here we report that the overall conservation level of expressed genes is lower at old age compared to young adulthood. This age‐related decrease in transcriptome conservation (ADICT) is systematically observed in diverse mammalian tissues, including the brain, liver, lung, and artery, but not in others, most notably in the muscle and heart. Where observed, ADICT is driven partly by poorly conserved genes being up‐regulated during aging. In general, the more often a gene is found up‐regulated with age among tissues and species, the lower its evolutionary conservation. Poorly conserved and up‐regulated genes have overlapping functional properties that include responses to age‐associated tissue damage, such as apoptosis and inflammation. Meanwhile, these genes do not appear to be under positive selection. Hence, genes contributing to old age phenotypes are found to harbor an excess of slightly deleterious alleles, at least in certain tissues. This supports the notion that genetic drift shapes aging in multicellular organisms, consistent with Medawar's mutation accumulation hypothesis.
Increased relapse to cocaine‐seeking in a genetic model for depression
Authors: Zilkha Noga , Barnea‐Ygael Noam , Keidar Liraz , Zangen Abraham
Published: May 2019

The greatest difficulty in treating cocaine addiction is the enormous rates of relapse, which occur despite immense negative consequences. Relapse risks are even greater in addicts with comorbid depression, perhaps because they use drugs to alleviate depressive symptoms. Only a few preclinical studies have examined this comorbidity, mostly exploring depressive‐like effects following drug exposure. We examined rats from two different depression‐like models: (a) chronic‐mild‐stress (CMS), which respond to antidepressant medications and (b) depressed‐rat‐line (DRL), a genetic model of selective breeding, which is less responsive to antidepressant medications. We tested addictive behaviors in a cocaine self‐administration procedure, including the “conflict model,” where drug‐seeking and relapse encounter adverse consequences: an electrified grid in front of the drug‐delivering lever. Following behavioral testing, we explored a potential association between behavioral outcomes and protein expression of brain‐derived neurotrophic factor (BDNF). We found that DRL rats self‐administer more cocaine compared with both CMS and controls, while CMS and control groups did not differ significantly. Notably, DRL but not CMS rats, displayed higher rates of relapse than controls, and expressed higher levels of BDNF in the prelimbic cortex (PLC). Potential translation of these results suggest that medication‐resistant depressed patients tend to consume more drugs and are more susceptible to relapse. The increase in PLC BDNF levels is consistent with previous rat models of depression, and concomitantly, with its suggested role in promoting cocaine‐seeking.
Exposure of the wild bee Osmia bicornis to the honey bee pathogen Nosema ceranae
Authors: Müller Uta , McMahon Dino P. , Rolff Jens
Published: May 2019

Wild bees are important pollinators for agricultural crops and solitary species such as Osmia bicornis are particularly suitable for pollination management. Wild bees share floral resources with managed honey bees and may be exposed to emerging infectious diseases. Although studies have explored the prevalence of pathogens in solitary wild bee species, data regarding the impact of pathogens on solitary bee health are lacking.

We carried out experiments examining whether the solitary bee species O. bicornis is susceptible to infection with the emerging pathogen Nosema ceranae and recorded the impact of exposure on survival.

The results obtained indicate that N. ceranae may be able to infect O. bicornis but its impact on host fitness is negligible: survival rates did not differ between control and inoculated bees, although male survival was marginally lower after infection. To explore the possible field‐relevance of our findings, we collected wild bees near an infected and a non‐infected hive and showed that N. ceranae was shared between managed and wild bees, although only the in presence of infected honey bees.

The findings of the present study show that O. bicornis is susceptible to pathogen spillover and could act as a potential reservoir host for N. ceranae in pollinator networks. Additional studies on this species incorporating sublethal effects, multiple infections and other interacting stressors are warranted.