bluuebunny/crossref_metadata_2025 huggingface dataset:
Divalent Metal Cations Potentiate the Predatory Capacity of Amoeba for Cryptococcus neoformans
Authors: Fu Man Shun , Casadevall Arturo
Published: November 2017

Among the best-studied interactions between soil phagocytic predators and a human-pathogenic fungus is that of
Acanthamoeba castellanii
and
Cryptococcus neoformans
. The experimental conditions used in amoeba-fungus confrontation assays can have major effects on whether the fungus or the protozoan is ascendant in the interaction. In the presence of Mg
2+
and Ca
2+
in phosphate-buffered saline (PBS),
C. neoformans
was consistently killed when incubated with
A. castellanii
.
A. castellanii
survived better in the presence of Mg
2+
and Ca
2+
, even when incubated with
C. neoformans
. In the absence of Mg
2+
and Ca
2+
,
C. neoformans
survived when incubated with
A. castellanii
, and the percentage of dead amoebae was higher than when incubated without yeast cells. These results show that the presence of Mg
2+
and Ca
2+
can make a decisive contribution toward tilting the outcome of the interaction in favor of the amoeba. Of the two metals, Mg
2+
had a stronger effect than Ca
2+
. The cations enhanced
A. castellanii
activity against
C. neoformans
via enhanced phagocytosis, which is the major mechanism by which amoebae kill fungal cells. We found no evidence that amoebae use extracellular killing mechanisms in their interactions with
C. neoformans
. In summary, the presence of Mg
2+
and Ca
2+
enhanced the cell adhesion on the surfaces and the motility of the amoeba, thus increasing the chance for contact with
C. neoformans
and the frequency of phagocytosis. Our findings imply that the divalent cation concentration in soils could be an important variable for whether amoebae can control
C. neoformans
in the environment.

IMPORTANCE
The grazing of soil organisms by phagocytic predators such as amoebae is thought to select for traits that enable some of them to acquire the capacity for virulence in animals. Consequently, knowledge about the interactions between amoebae and soil microbes, such as pathogenic fungi, is important for understanding how virulence can emerge. We show that the interaction between an amoeba and the pathogenic fungus
C. neoformans
is influenced by the presence in the assay of magnesium and calcium, which potentiate amoebae. The results may also have practical applications, since enriching soils with divalent cations may reduce
C. neoformans
numbers in contaminated soils.
Sinorhizobium meliloti Glutathione Reductase Is Required for both Redox Homeostasis and Symbiosis
Authors: Tang Guirong , Li Ningning , Liu Yumin , Yu Liangliang , Yan Junhui , Luo Li
Published: November 2017

Glutathione (
l
-γ-glutamyl-
l
-cysteinylglycine) (GSH), one of the key antioxidants in
Sinorhizobium meliloti
, is required for the development of alfalfa (
Medicago sativa
) nitrogen-fixing nodules. Glutathione exists as either reduced glutathione (GSH) or oxidized glutathione (GSSG), and its content is regulated by two pathways in
S. meliloti
. The first pathway is the
de novo
synthesis of glutathione from its constituent amino acids, namely, Glu, Cys, and Gly, catalyzed by γ-glutamylcysteine synthetase (GshA) and glutathione synthetase (GshB). The second pathway is the recycling of GSSG via glutathione reductase (GR). However, whether the
S. meliloti
GR functions similarly to GshA and GshB1 during symbiotic interactions with alfalfa remains unknown. In this study, a plasmid insertion mutation of the
S. meliloti
gor
gene, which encodes GR, was constructed, and the mutant exhibited delayed alfalfa nodulation, with 75% reduction in nitrogen-fixing capacity. The
gor
mutant demonstrated increased accumulation of GSSG and a decreased GSH/GSSG ratio in cells. The mutant also showed defective growth in rich broth and minimal broth and was more sensitive to the oxidants H
2
O
2
and sodium nitroprusside. Interestingly, the expression of
gshA
,
gshB1
,
katA
, and
katB
was induced in the mutant. These findings reveal that the recycling of glutathione is important for
S. meliloti
to maintain redox homeostasis and to interact symbiotically with alfalfa.

IMPORTANCE
The antioxidant glutathione is regulated by its synthetase and reductase in cells. In the symbiotic bacterium
S. meliloti
, the
de novo
synthesis of glutathione is essential for alfalfa nodulation and nitrogen fixation. In this study, we observed that the recycling of glutathione from GSSG not only was required for redox homeostasis and oxidative stress protection in
S. meliloti
cells but also contributed to alfalfa nodule development and competition capacity. Our findings demonstrate that the recycling of glutathione plays a key role in nitrogen fixation symbiosis.
Multi-omics Reveals the Lifestyle of the Acidophilic, Mineral-Oxidizing Model Species Leptospirillum ferriphilum
T
Authors: Christel Stephan , Herold Malte , Bellenberg Sören , El Hajjami Mohamed , Buetti-Dinh Antoine , Pivkin Igor V. , Sand Wolfgang , Wilmes Paul , Poetsch Ansgar , Dopson Mark
Published: November 2017

Leptospirillum ferriphilum
plays a major role in acidic, metal-rich environments, where it represents one of the most prevalent iron oxidizers. These milieus include acid rock and mine drainage as well as biomining operations. Despite its perceived importance, no complete genome sequence of the type strain of this model species is available, limiting the possibilities to investigate the strategies and adaptations that
Leptospirillum ferriphilum
DSM 14647
T
(here referred to as
Leptospirillum ferriphilum
T
) applies to survive and compete in its niche. This study presents a complete, circular genome of
Leptospirillum ferriphilum
T
obtained by PacBio single-molecule real-time (SMRT) long-read sequencing for use as a high-quality reference. Analysis of the functionally annotated genome, mRNA transcripts, and protein concentrations revealed a previously undiscovered nitrogenase cluster for atmospheric nitrogen fixation and elucidated metabolic systems taking part in energy conservation, carbon fixation, pH homeostasis, heavy metal tolerance, the oxidative stress response, chemotaxis and motility, quorum sensing, and biofilm formation. Additionally, mRNA transcript counts and protein concentrations were compared between cells grown in continuous culture using ferrous iron as the substrate and those grown in bioleaching cultures containing chalcopyrite (CuFeS
2
). Adaptations of
Leptospirillum ferriphilum
T
to growth on chalcopyrite included the possibly enhanced production of reducing power, reduced carbon dioxide fixation, as well as elevated levels of RNA transcripts and proteins involved in heavy metal resistance, with special emphasis on copper efflux systems. Finally, the expression and translation of genes responsible for chemotaxis and motility were enhanced.

IMPORTANCE
Leptospirillum ferriphilum
is one of the most important iron oxidizers in the context of acidic and metal-rich environments during moderately thermophilic biomining. A high-quality circular genome of
Leptospirillum ferriphilum
T
coupled with functional omics data provides new insights into its metabolic properties, such as the novel identification of genes for atmospheric nitrogen fixation, and represents an essential step for further accurate proteomic and transcriptomic investigation of this acidophile model species in the future. Additionally, light is shed on adaptation strategies of
Leptospirillum ferriphilum
T
for growth on the copper mineral chalcopyrite. These data can be applied to deepen our understanding and optimization of bioleaching and biooxidation, techniques that present sustainable and environmentally friendly alternatives to many traditional methods for metal extraction.
The Swinholide Biosynthesis Gene Cluster from a Terrestrial Cyanobacterium, Nostoc sp. Strain UHCC 0450
Authors: Humisto Anu , Jokela Jouni , Liu Liwei , Wahlsten Matti , Wang Hao , Permi Perttu , Machado João Paulo , Antunes Agostinho , Fewer David P. , Sivonen Kaarina
Published: November 2017

Swinholides are 42-carbon ring polyketides with a 2-fold axis of symmetry. They are potent cytotoxins that disrupt the actin cytoskeleton. Swinholides were discovered from the marine sponge
Theonella
sp. and were long suspected to be produced by symbiotic bacteria. Misakinolide, a structural variant of swinholide, was recently demonstrated to be the product of a symbiotic heterotrophic proteobacterium. Here, we report the production of swinholide A by an axenic strain of the terrestrial cyanobacterium
Nostoc
sp. strain UHCC 0450. We located the 85-kb
trans
-AT polyketide synthase (PKS) swinholide biosynthesis gene cluster from a draft genome of
Nostoc
sp. UHCC 0450. The swinholide and misakinolide biosynthesis gene clusters share an almost identical order of catalytic domains, with 85% nucleotide sequence identity, and they group together in phylogenetic analysis. Our results resolve speculation around the true producer of swinholides and demonstrate that bacteria belonging to two distantly related phyla both produce structural variants of the same natural product. In addition, we described a biosynthesis cluster from
Anabaena
sp. strain UHCC 0451 for the synthesis of the cytotoxic and antifungal scytophycin. All of these biosynthesis gene clusters were closely related to each other and created a group of cytotoxic macrolide compounds produced by
trans
-AT PKSs of cyanobacteria and proteobacteria.

IMPORTANCE
Many of the drugs in use today originate from natural products. New candidate compounds for drug development are needed due to increased drug resistance. An increased knowledge of the biosynthesis of bioactive compounds can be used to aid chemical synthesis to produce novel drugs. Here, we show that a terrestrial axenic culture of
Nostoc
cyanobacterium produces swinholides, which have been previously found only from marine sponge or samples related to them. Swinholides are polyketides with a 2-fold axis of symmetry, and they are potent cytotoxins that disrupt the actin cytoskeleton. We describe the biosynthesis gene clusters of swinholide from
Nostoc
cyanobacteria, as well as the related cytotoxic and antifungal scytophycin from
Anabaena
cyanobacteria, and we study the evolution of their
trans
-AT polyketide synthases. Interestingly, swinholide is closely related to misakinolide produced by a symbiotic heterotrophic proteobacterium, demonstrating that bacteria belonging to two distantly related phyla and different habitats can produce similar natural products.
Draft Genome Sequences of 23 Salmonella enterica Strains Isolated from Cattle in Ibadan, Nigeria, Representing 21
Salmonella
Serovars
Authors: Sanchez Leon Maria , Fashae Kayode , Kastanis George , Allard Marc
Published: November 2017

To provide a better understanding of the diversity of
Salmonella enterica
, we report the assembled genome sequences of 23
Salmonella enterica
strains isolated from fecal samples of cattle in Nigeria comprising 21 different
Salmonella
serovars.
Whole-Genome Sequence of Salmonella enterica subsp.
enterica
Serovar Typhimurium Strain UPM 260, Isolated from a Broiler Chicken in Perak, Malaysia
Authors: Roslan Najwa Syahirah , Jabeen Shagufta , Mat Isa Nurulfiza , Omar Abdul Rahman , Bejo Mohd Hair , Ideris Aini
Published: November 2017

Salmonella enterica
subsp.
enterica
serovar Typhimurium is one of several well-categorized
Salmonella
serotypes recognized globally. Here, we report the whole-genome sequence of
S
. Typhimurium strain UPM 260, isolated from a broiler chicken.
Draft Genome Sequence of Carbapenemase-Producing Serratia marcescens Isolated from a Patient with Chronic Obstructive Pulmonary Disease
Authors: Lepuschitz Sarah , Sorschag Sieglinde , Springer Burkhard , Allerberger Franz , Ruppitsch Werner
Published: November 2017

The occurrence of multidrug-resistant
Serratia marcescens
strains producing metallo-β-lactamases or extended-spectrum β-lactamases represents a serious public health threat. Here, we report the draft genome sequence of a multidrug-resistant carbapenemase-producing
Serratia marcescens
isolate recovered from the bronchoalveolar lavage specimen of a patient suffering from chronic obstructive pulmonary disease (COPD).
Complete Genome Sequence of Bacillus cereus C1L, a Plant Growth-Promoting Rhizobacterium from the Rhizosphere of Formosa Lily in Taiwan
Authors: Huang Chien-Jui , Zheng Po-Xing , Ou Jheng-Yang , Lin Yao-Cheng , Chen Chao-Ying
Published: November 2017

Bacillus cereus
C1L, a plant growth-promoting rhizobacterium, provides protection against fungal pathogens in monocot plants. To gain new insights into the biocontrol mechanisms used by this rhizobacterium, we determined the complete genome sequence of
B. cereus
C1L. One chromosome and three plasmids were identified with a total size of ~6.0 Mb.
A Simulator-Assisted Workshop for Teaching Chemostat Cultivation in Academic Classes on Microbial Physiology
Authors: Hakkaart Xavier D. V. , Pronk Jack T. , van Maris Antonius J. A.
Published: November 2017

Understanding microbial growth and metabolism is a key learning objective of microbiology and biotechnology courses, essential for understanding microbial ecology, microbial biotechnology and medical microbiology. Chemostat cultivation, a key research tool in microbial physiology that enables quantitative analysis of growth and metabolism under tightly defined conditions, provides a powerful platform to teach key features of microbial growth and metabolism.

Substrate-limited chemostat cultivation can be mathematically described by four equations. These encompass mass balances for biomass and substrate, an empirical relation that describes distribution of consumed substrate over growth and maintenance energy requirements (Pirt equation), and a Monod-type equation that describes the relation between substrate concentration and substrate-consumption rate. The authors felt that the abstract nature of these mathematical equations and a lack of visualization contributed to a suboptimal operative understanding of quantitative microbial physiology among students who followed their Microbial Physiology B.Sc. courses.

The studio-classroom workshop presented here was developed to improve student understanding of quantitative physiology by a set of question-guided simulations. Simulations are run on Chemostatus, a specially developed MATLAB-based program, which visualizes key parameters of simulated chemostat cultures as they proceed from dynamic growth conditions to steady state.

In practice, the workshop stimulated active discussion between students and with their teachers. Moreover, its introduction coincided with increased average exam scores for questions on quantitative microbial physiology. The workshop can be easily implemented in formal microbial physiology courses or used by individuals seeking to test and improve their understanding of quantitative microbial physiology and/or chemostat cultivation.
A Laboratory Activity Demonstrating the Antibacterial Effects of Extracts from Two Plant Species,
Moringa oleifera
and
Allium sativum
(Garlic)
Authors: Miller Grace J. , Cunningham Anna M. G. , Iwase Yui , Lautensack Nicole L. , Sattley W. Matthew
Published: November 2017

A variety of plants synthesize natural products that either kill or inhibit the growth of various microorganisms. These plant products may serve as useful natural alternatives to synthetic antimicrobial pharmaceuticals and can be especially important in regions where commercial drugs are often not available. Despite this, the role of plants as producers of natural antimicrobial agents is often understated or even ignored in undergraduate biology curricula. In this laboratory exercise, students extract water-soluble constituents from two plants,
Moringa oleifera
(moringa) and
Allium sativum
(garlic), and determine their activity against both a gram-positive (
Bacillus cereus
strain 971) and a gram-negative (
Escherichia coli
strain K12) bacterium using a disk diffusion assay on Mueller-Hinton agar. Disks infused with commercially available antibiotics (e.g., penicillin and tetracycline) serve as controls. Following an incubation period of 24 hours, students obtain quantitative data by measuring zones of growth inhibition that develop as a result of strain sensitivity. To determine the effectiveness of the learning objectives, an unannounced quiz was administered both before and after the activity, and the students showed significant gains in their understanding of key concepts. Because this activity combines aspects of two major branches of biology—plant biology and microbiology—it is suitable for use as a laboratory exercise in courses related to either discipline, or it may be used as a laboratory component of a general biology course.
Concept Inventory Development Reveals Common Student Misconceptions about Microbiology
Authors: Briggs Amy G. , Hughes Lee E. , Brennan Robert E. , Buchner John , Horak Rachel E. A. , Amburn D. Sue Katz , McDonald Ann H. , Primm Todd P. , Smith Ann C. , Stevens Ann M. , Yung Sunny B. , Paustian Timothy D.
Published: November 2017

Misconceptions, or alternative conceptions, are incorrect understandings that students have incorporated into their prior knowledge. The goal of this study was the identification of misconceptions in microbiology held by undergraduate students upon entry into an introductory, general microbiology course. This work was the first step in developing a microbiology concept inventory based on the American Society for Microbiology’s Recommended Curriculum Guidelines for Undergraduate Microbiology. Responses to true/false (T/F) questions accompanied by written explanations by undergraduate students at a diverse set of institutions were used to reveal misconceptions for fundamental microbiology concepts. These data were analyzed to identify the most difficult core concepts, misalignment between explanations and answer choices, and the most common misconceptions for each core concept. From across the core concepts, nineteen misconception themes found in at least 5% of the coded answers for a given question were identified. The top five misconceptions, with coded responses ranging from 19% to 43% of the explanations, are described, along with suggested classroom interventions. Identification of student misconceptions in microbiology provides a foundation upon which to understand students’ prior knowledge and to design appropriate tools for improving instruction in microbiology.
Development, Validation, and Application of the Microbiology Concept Inventory
Authors: Paustian Timothy D. , Briggs Amy G. , Brennan Robert E. , Boury Nancy , Buchner John , Harris Shannon , Horak Rachel E. A. , Hughes Lee E. , Katz-Amburn D. Sue , Massimelli Maria J. , McDonald Ann H. , Primm Todd P. , Smith Ann C. , Stevens Ann M. , Yung Sunny B.
Published: November 2017

If we are to teach effectively, tools are needed to measure student learning. A widely used method for quickly measuring student understanding of core concepts in a discipline is the concept inventory (CI). Using the American Society for Microbiology Curriculum Guidelines (ASMCG) for microbiology, faculty from 11 academic institutions created and validated a new microbiology concept inventory (MCI). The MCI was developed in three phases. In phase one, learning outcomes and fundamental statements from the ASMCG were used to create T/F questions coupled with open responses. In phase two, the 743 responses to MCI 1.0 were examined to find the most common misconceptions, which were used to create distractors for multiple-choice questions. MCI 2.0 was then administered to 1,043 students. The responses of these students were used to create MCI 3.0, a 23-question CI that measures students’ understanding of all 27 fundamental statements. MCI 3.0 was found to be reliable, with a Cronbach’s alpha score of 0.705 and Ferguson’s delta of 0.97. Test item analysis demonstrated good validity and discriminatory power as judged by item difficulty, item discrimination, and point-biserial correlation coefficient. Comparison of pre- and posttest scores showed that microbiology students at 10 institutions showed an increase in understanding of concepts after instruction, except for questions probing metabolism (average normalized learning gain was 0.15). The MCI will enable quantitative analysis of student learning gains in understanding microbiology, help to identify misconceptions, and point toward areas where efforts should be made to develop teaching approaches to overcome them.
Using Backward Design in Education Research: A Research Methods Essay
Authors: Jensen Jamie L. , Bailey Elizabeth G. , Kummer Tyler A. , Weber K. Scott
Published: November 2017

Education research within the STEM disciplines applies a scholarly approach to teaching and learning, with the intent of better understanding how people learn and of improving pedagogy at the undergraduate level. Most of the professionals practicing in this field have ‘crossed over’ from other disciplinary fields and thus have faced challenges in becoming experts in a new discipline. In this article, we offer a novel framework for approaching education research design called Backward Design in Education Research. It is patterned on backward curricular design and provides a three-step, systematic approach to designing education projects: 1) Define a research question that leads to a testable causal hypothesis based on a theoretical rationale; 2) Choose or design the assessment instruments to test the research hypothesis; and 3) Develop an experimental protocol that will be effective in testing the research hypothesis. This approach provides a systematic method to develop and carry out evidence-based research design.
Are the early predictors of long-term work absence following injury time dependent? Results from the Prospective Outcomes of Injury Study
Authors: Lilley Rebbecca , Davie Gabrielle , Derrett Sarah
Published: November 2017

Objectives

Few studies examine the influence of early predictors of work absence beyond 12 months following injury or the time-dependent relative importance of these factors. This study aimed to identify the most important sociodemographic, occupational, health, lifestyle and injury predictors of work absence at 12 and 24 months following injury and to examine changes in the relative importance of these over time.

Design

Prospective cohort study.

Setting

The Prospective Outcomes of Injury Study, New Zealand.

Participants

2626 injured New Zealand workers aged 18–64 years were identified from the Prospective Outcomes of Injury Study recruited form New Zealand’s monopoly injury compensation provider injury claims register: 2092 completed the 12-month interview (80% follow-up) and 2082 completed the 24-month interview (79% follow-up).

Primary and secondary outcomes measures

The primary outcomes of interest was absence from work at the time of the 12-month and 24-month follow-up interviews.

Results

Using modified Poisson regression to estimate relative risks, important groups of workers were identified at increased risk of work absence at both 12 and 24 months: males, low-income workers, trade/manual workers, temporary employees, those reporting two or more comorbidities and those experiencing a work-related injury. Important factors unique to predicting work absence at 12 months included financial insecurity, fixed-term employment and long weekly hours worked; unique factors at 24 months included job dissatisfaction, long weekly days worked, a prior injury and sustaining an injury that was perceived to be a threat to life.

Conclusions

Important early predictors of work absence at 12 or 24 months following injury are multidimensional and have a time dependent pattern. A consistent set of predictors was, however, present at both time periods that are prime for early intervention. Understanding the multidimensional, time-dependent patterns of early predictors of long-term disability is important to optimally target timely interventions to prevent long-term work disability.
Impact of preterm birth on parental separation: a French population-based longitudinal study
Authors: Nusinovici Simon , Olliac Bertrand , Flamant Cyril , Müller Jean-Baptiste , Olivier Marion , Rouger Valérie , Gascoin Géraldine , Basset Hélène , Bouvard Charlotte , Rozé Jean-Christophe , Hanf Matthieu
Published: November 2017

Objective

The objective of this study was to investigate both the effects of low gestational age and infant’s neurodevelopmental outcome at 2 years of age on the risk of parental separation within 7 years of giving birth.

Design

Prospective.

Setting

24 maternity clinics in the Pays-de-la-Loire region.

Participants

This study included 5732 infants delivered at <35 weeks of gestation born between 2005 and 2013 who were enrolled in the population-based Loire Infant Follow-up Team cohort and who had a neurodevelopmental evaluation at 2 years. This neurodevelopmental evaluation was based on a physical examination, a psychomotor evaluation and a parent-completed questionnaire.

Outcome measure

Risk of parental separation (parents living together or parents living separately).

Results

Ten percent (572/5732) of the parents reported having undergone separation during the follow-up period. A mediation analysis showed that low gestational age had no direct effect on the risk of parental separation. Moreover, a non-optimal neurodevelopment at 2 years was associated with an increased risk of parental separation corresponding to a HR=1.49(1.23 to 1.80). Finally, the increased risk of parental separation was aggravated by low socioeconomic conditions.

Conclusions

The effect of low gestational age on the risk of parental separation was mediated by the infant’s neurodevelopment.
Platelet rich Plasma in Achilles Tendon Healing 2 (PATH-2) trial: protocol for a multicentre, participant and assessor-blinded, parallel-group randomised clinical trial comparing platelet-rich plasma (PRP) injection versus placebo injection for Achilles tendon rupture
Authors: Alsousou Joseph , Keene David J , Hulley Philippa A , Harrison Paul , Wagland Susan , Byrne Christopher , Schlüssel Michael Maia , Dutton Susan J , Lamb Sarah E , Willett Keith
Published: November 2017

Background

Achilles tendon injuries give rise to substantial long-lasting morbidity and pose considerable challenges for clinicians and patients during the lengthy healing period. Current treatment strategies struggle to curb the burden of this injury on health systems and society due to lengthy rehabilitation, work absence and reinjury risk. Platelet-rich plasma (PRP) is an autologous preparation that has been shown to improve the mechanobiological properties of tendons in laboratory and animal studies. The use of PRP in musculoskeletal injuries is on the increase despite the lack of adequately powered clinical studies.

Methods and design

This is a multicentre randomised controlled trial to evaluate the efficacy and mechanism of PRP in patients with acute Achilles tendon rupture (ATR). All adults with acute ATR presenting within 12 days of the injury who are to be treated non-operatively are eligible. A total of 230 consenting patients will be randomly allocated via a remote web-based service to receive PRP injection or placebo injection to the site of the injury. All participants will be blinded to the intervention and will receive standardised rehabilitation to reduce efficacy interference.

Participants will be followed up with blinded assessments of muscle–tendon function, quality of life, pain and overall patient’s functional goals at 4, 7, 13, 24 weeks and 24 months post-treatment. The primary outcome is the heel-rise endurance test (HRET), which will be supervised by a blinded assessor at 24 weeks. A subgroup of 16 participants in one centre will have needle biopsy under ultrasound guidance at 6 weeks. Blood and PRP will be analysed for cell count, platelet activation and growth factor concentrations.

Ethics and dissemination

The protocol has been approved by the Oxfordshire Research Ethics Committee (Oxfordshire Research Ethics Committee A, reference no 14/SC/1333). The trial will be reported in accordance with the CONSORT statement and published in peer-reviewed scientific journals.

Trial registration number

ISRCTN: 54992179, assigned 12 January 2015. ClinicalTrials.gov:NCT02302664, received 18 November 2014. UK Clinical Research Network Study Portfolio Database: ID 17850.
Biochemical monitoring after initiation of aldosterone antagonist therapy in users of renin–angiotensin system blockers: a UK primary care cohort study
Authors: Sinnott Sarah-Jo , Mansfield Kathryn E , Schmidt Morten , Bhaskaran Krishnan , Smeeth Liam , Nitsch Dorothea , Tomlinson Laurie A
Published: November 2017

Objective

To determine the frequency of biochemical monitoring after initiation of aldosterone antagonists(AA) in patients also using angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEI/ARB).

Setting

UK primary care.

Participants

ACEI/ARB users who initiated AA between 2004 and 2014.

Outcomes

We calculated the proportions with: (1) biochemical monitoring ≤2 weeks post initiation of AA, (2) adverse biochemical values ≤2 months (potassium ≥6 mmol/L, creatinine ≥220 µmol/L and ≥30% increase in creatinine from baseline) and (3) discontinuers of AA in those with an adverse biochemical value. We used logistic regression to study patient characteristics associated with monitoring and adverse biochemical values.

Results

In 10 546 initiators of AA, 3291 (31.2%) had a record of biochemical monitoring ≤2 weeks post initiation. A total of 2.0% and 2.7% of those with follow-up monitoring within 2 months of initiation experienced potassium ≥6 mmol/L and creatinine ≥220 µmol/L, respectively, whereas 13.5% had a ≥30% increase in creatinine. Baseline potassium (OR 3.59, 95% CI 2.43 to 5.32 for 5.0–5.5 mmol/L compared with <5.0 mmol/L) and estimated glomerular filtration rate 45-59 ml/min/1.73 m2(OR 2.06, 95% CI 1.26 to 3.35 compared with ≥60 ml/min/1.73 m2) were independently predictive of potassium ≥6 mmol/L. Women and people with diabetes had higher odds of ≥30% increase in creatinine.

Conclusion

Less than one-third of patients taking ACEI/ARB had biochemical monitoring within 2 weeks of initiating AAs. Higher levels of monitoring may reduce adverse biochemical events.
Patient-level and practice-level factors associated with consultation duration: a cross-sectional analysis of over one million consultations in English primary care
Authors: Stevens Sarah , Bankhead Clare , Mukhtar Toqir , Perera-Salazar Rafael , Holt Tim A , Salisbury Chris , Hobbs F D Richard
Published: November 2017

Objectives

Consultation duration has previously been shown to be associated with patient, practitioner and practice characteristics. However, previous studies were conducted outside the UK, considered only small numbers of general practitioner (GP) consultations or focused primarily on practitioner-level characteristics. We aimed to determine the patient-level and practice-level factors associated with duration of GP and nurse consultations in UK primary care.

Design and setting

Cross-sectional data were obtained from English general practices contributing to the Clinical Practice Research Datalink (CPRD) linked to data on patient deprivation and practice staffing, rurality and Quality and Outcomes Framework (QOF) achievement.

Participants

218 304 patients, from 316 English general practices, consulting from 1 April 2013 to 31 March 2014.

Analysis

Multilevel mixed-effects models described the association between consultation duration and patient-level and practice-level factors (patient age, gender, smoking status, ethnic group, deprivation and practice rurality, number of full-time equivalent GPs/nurses, list size, consultation rate, quintile of overall QOF achievement and training status).

Results

Mean duration of face-to-face GP consultations was 9.24 min and 5.32 min for telephone consultations. Nurse face-to-face and telephone consultations lasted 9.70 and 5.73 min on average, respectively. Longer GP consultation duration was associated with female patient gender, practice training status and older patient age. Shorter duration was associated with higher deprivation and consultation rate. Longer nurse consultation duration was associated with male patient gender, older patient age and ever smoking; and shorter duration with higher consultation rate. Observed differences in duration were small (eg, GP consultations with female patients compared with male patients were 8 s longer on average).

Conclusions

Small observed differences in consultation duration indicate that patients are treated similarly regardless of background. Increased consultation duration may be beneficial for older or comorbid patients, but the benefits and costs of increased consultation duration require further study.
Risk factors for recurrent intussusception in children: a retrospective cohort study
Authors: Guo Wan-liang , Hu Zhang-chun , Tan Ya-lan , Sheng Mao , Wang Jian
Published: November 2017

Objective

The aim of this study was to assess the frequency of clinical features and pathological lead points in recurrent intussusception, with a special focus on the risk factors that lead to recurrent intussusception.

Design

This is a retrospective cohort study. A 5-year retrospective study was performed between January 2012 and July 2016 in the Children’s Hospital of Soochow University, Suzhou, China, to determine the clinical features and pathological lead points of recurrent intussusception.

Setting

This is a retrospective chart review of recurrent intussusception cases in a large university teaching hospital.

Participants

The medical records were obtained for 1007 cases with intussusception, including demographics, clinical signs and symptoms, imaging and recurrence times if available.

Interventions

Univariate and multivariate logistic regression analyses were used to measure significant factors affecting recurrent intussusception and recurrent intussusception with pathological lead points.

Results

There were 481 total episodes of recurrence in 191 patients. Among these, 87 had one recurrence and 104 had multiple recurrences. After comparing recurrent and non-recurrent intussusception cases using univariate analysis, it was determined that the factors associated with recurrent intussusception were age (>1 year), duration of symptoms (≤12 hours), the lack of bloody stool, paroxysmal crying or vomiting, the mass location (right abdomen) and pathological lead point (P<0.05). Age (>1 year), duration of symptoms (≤12 hours), the absence of vomiting, mass location (right abdomen) and pathological lead point were significantly independently predictive of recurrent intussusception. The factors associated with recurrent intussusception with lead points present were vomiting and mass location in the right abdomen (P<0.05). Vomiting and mass location (left abdomen) were significantly predictive of recurrent intussusception with lead points.

Conclusions

Age (>1 year), symptom duration (≤12 hours), the absence of vomiting, mass location (right abdomen) and pathological lead points were significantly predictive of recurrent intussusception. Vomiting and mass location (left abdomen) were significantly predictive of recurrent intussusception with lead points.
Non-invasive markers of liver fibrosis in fatty liver disease are unreliable in people of South Asian descent
Authors: De Silva Sampath , Li Wenhao , Kemos Polychronis , Brindley James H , Mecci Jibran , Samsuddin Salma , Chin-Aleong Joanne , Feakins Roger M , Foster Graham R , Syn Wing-Kin , Alazawi William
Published: November 2017

Objective

Liver biopsy is the most accurate method for determining stage and grade of injury in non-alcoholic fatty liver disease (NAFLD). Given risks and limitations of biopsy, non-invasive tests such as NAFLD fibrosis score, aspartate transaminase (AST) to platelet ratio index, Fib-4, AST/alanine transaminase ratio and BARD are used. Prevalence and severity of NAFLD and metabolic syndrome vary by ethnicity, yet tests have been developed in largely white populations. We tested our hypothesis that non-invasive tests that include metabolic parameters are less accurate in South Asian compared with white patients.

Design

Retrospective cross-sectional.

Setting

Specialist liver centre.

Patients

Patients with histologically confirmed NAFLD.

Interventions

Scores calculated using clinical data taken within 1 week and compared with histology (Kleiner).

Main outcome measures

Diagnostic test characteristics.

Results

175 patients were identified. South Asians (n=90) were younger, had lower body mass index and lower proportion of obesity compared with white patients (n=79), with comparable rates of diabetes and liver injury. Tests are less sensitive at detecting advanced fibrosis in South Asian compared with white patients. Relative risk of correct diagnosis in white patients compared with South Asians is 1.86 (95% CI 1.4 to 2.6). In binary logistic regression models, ethnicity and platelet count predicted accuracy. Transient elastography was equally and highly accurate in both ethnicities.

Conclusions

Blood test-based non-invasive scores are less accurate in South Asian patients, irrespective of metabolic parameters. Ethnicity should be considered when devising risk-stratification algorithms for NAFLD.
Cumulative burden of inflammation predicts colorectal neoplasia risk in ulcerative colitis: a large single-centre study
Authors: Choi Chang-Ho Ryan , Al Bakir Ibrahim , Ding Nik-Sheng (John) , Lee Gui-Han , Askari Alan , Warusavitarne Janindra , Moorghen Morgan , Humphries Adam , Ignjatovic-Wilson Ana , Thomas-Gibson Siwan , Saunders Brian P , Rutter Matthew D , Graham Trevor A , Hart Ailsa L
Published: November 2017

Objective

Ulcerative colitis (UC) is a dynamic disease with its severity continuously changing over time. We hypothesised that the risk of colorectal neoplasia (CRN) in UC closely follows an actuarial accumulative inflammatory burden, which is inadequately represented by current risk stratification strategies.

Design

This was a retrospective single-centre study. Patients with extensive UC who were under colonoscopic surveillance between 2003 and 2012 were studied. Each surveillance episode was scored for a severity of microscopic inflammation (0=no activity; 1=mild; 2=moderate; 3=severe activity). The cumulative inflammatory burden (CIB) was defined as sum of: average score between each pair of surveillance episodes multiplied by the surveillance interval in years. Potential predictors were correlated with CRN outcome using time-dependent Cox regression.

Results

A total of 987 patients were followed for a median of 13 years (IQR, 9-18), 97 (9.8%) of whom developed CRN. Multivariate analysis showed that the CIB was significantly associated with CRN development (HR, 2.1 per 10-unit increase in CIB (equivalent of 10, 5 or 3.3 years of continuous mild, moderate or severe active microscopic inflammation); 95% CI 1.4 to 3.0; P<0.001). Reflecting this, while inflammation severity based on the most recent colonoscopy alone was not significant (HR, 0.9 per-1-unit increase in severity; 95% CI 0.7 to 1.2; P=0.5), a mean severity score calculated from all colonoscopies performed in preceding 5 years was significantly associated with CRN risk (HR, 2.2 per-1-unit increase; 95% CI 1.6 to 3.1; P<0.001).

Conclusion

The risk of CRN in UC is significantly associated with accumulative inflammatory burden. An accurate CRN risk stratification should involve assessment of multiple surveillance episodes to take this into account.
Can a documentary increase help-seeking intentions in men? A randomised controlled trial
Authors: King Kylie Elizabeth , Schlichthorst Marisa , Spittal Matthew J , Phelps Andrea , Pirkis Jane
Published: November 2017

Background

We investigated whether a public health intervention—a three-part documentary calledMan Upwhich explored the relationship between masculinity and mental health, well-being and suicidality—could increase men’s intentions to seek help for personal and emotional problems.

Methods

We recruited men aged 18 years or over who were not at risk of suicide to participate in a double-blind randomised controlled trial. Participants were randomly assigned (1:1) via computer randomisation to viewMan Up(the intervention) or a control documentary. We hypothesised that 4 weeks after viewingMan Upparticipants would report higher levels of intention to seek help than those who viewed the control documentary. Our primary outcome was assessed using the General Help Seeking Questionnaire, and was analysed for all participants. The trial was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12616001169437, Universal Trial Number: U1111-1186-1459) and was funded by the Movember Foundation.

Results

Three hundred and fifty-four men were assessed for eligibility for the trial and randomised to viewMan Upor the control documentary. Of these, 337 completed all stages (nine participants were lost to follow-up in the intervention group and eight in the control group). Linear regression analysis showed a significant increase in intentions to seek help in the intervention group, but not in the control group (coef.=2.06, 95% CI 0.48 to 3.63, P=0.01).

Conclusions

Our trial demonstrates the potential for men’s health outcomes to be positively impacted by novel, media-based public health interventions that focus on traditional masculinity.

Trial registration number

ACTRN12616001169437, Results.
Autonomy, nudging and post-truth politics
Authors: Keeling Geoff
Published: November 2017

In his excellent essay, ‘Nudges in a post-truth world’, Neil Levy argues that ‘nudges to reason’, or nudges which aim to make us more receptive to evidence, are morally permissible. A strong argument against the moral permissibility of nudging is that nudges fail to respect the autonomy of the individuals affected by them. Levy argues that nudges to reason do respect individual autonomy, such that the standard autonomy objection fails against nudges to reason. In this paper, I argue that Levy fails to show that nudges to reason respect individual autonomy.
Homothetic matter collineations of LRS Bianchi type I spacetimes
Authors: Hussain Tahir , Rahim Waqas
Published: November 2017

A complete classification of locally rotationally symmetric (LRS) Bianchi type I spacetimes via homothetic matter collineations (HMCs) is presented. For non-degenerate energy–momentum tensor, a general form of the vector field generating HMCs is found, subject to some integrability conditions. Solving the integrability conditions in different cases, it is found that the LRS Bianchi type I spacetimes admit 6-, 7-, 8-, 10- or 11-dimensional Lie algebra of HMCs. When the energy–momentum tensor is degenerate, two cases give 6 and 11 HMCs, while the remaining cases produce infinite number of HMCs. Some LRS Bianchi type I metrics are provided admitting HMCs.
Radiative corrections and instability of large Q-balls
Authors: Kovtun A. V. , Nugaev E. Ya.
Published: November 2017

We discuss stability of Q-balls interacting with fermions in theory with small coupling constant [Formula: see text]. We argue that for configurations with large global U(1)-charge [Formula: see text], the problem of classical stability becomes more subtle. For example, in model with flat direction there is maximal value of charge for stable solutions with [Formula: see text]. This result may be crucial for the self-consistent consideration of Q-ball evaporation into the fermions. We study the origin of additional instability and discuss possible ways to avoid it.
Adaptive Partition-Cluster-Based Median Filter for Random-Valued Impulse Noise Removal
Authors: Pang Ke , Shi Zaifeng , Xu Jiangtao , Yao Suying
Published: November 2017

As the most popular nonlinear denoise technique, the median filter has attracted significant attention in recent years. In this paper, a novel adaptive median filter is presented to remove random-valued impulse noise in images, named Adaptive Partition-Cluster-Based Median (APCM) Filter. Based on the partition cluster idea, the noise detector classifies pixels into different groups and identifies the noisy pixels in different regions adaptively without iterations. According to the results of noise detection, an improved adaptive decision-based filter is presented to restore the pixels which are corrupted by random-valued impulse noise. The proposed filter technique is open to any impulse noise. Extensive simulation results demonstrate that the proposed method substantially outperforms other state-of-the-arts impulse noise filter techniques both visually and in terms of objective quality measures. Furthermore, the proposed method is much friendly to the hardware parallel implementation of image processing because of its low computation complexity and simple realizable structure.
CHAM: Improving Prefetch Efficiency Using a Composite Hierarchy-Aware Method
Authors: Qian Cheng , Huang Libo , Yu Qi , Wang Zhiying
Published: November 2017

Hardware prefetching has always been a crucial mechanism to improve processor performance. However, an efficient prefetch operation requires a guarantee of high prefetch accuracy; otherwise, it may degrade system performance. Prior studies propose an adaptive priority controlling method to make better use of prefetch accesses, which improves performance in two-level cache systems. However, this method does not perform well in a more complex memory hierarchy, such as a three-level cache system. Thus, it is still necessary to explore the efficiency of prefetch, in particular, in complex hierarchical memory systems.

In this paper, we propose a composite hierarchy-aware method called CHAM, which works at the middle level cache (MLC). By using prefetch accuracy as an evaluation criterion, CHAM improves the efficiency of prefetch accesses based on (1) a dynamic adaptive prefetch control mechanism to schedule the priority and data transfer of prefetch accesses across the cache hierarchical levels in the runtime and (2) a prefetch efficiency-oriented hybrid cache replacement policy to select the most suitable policy. To demonstrate its effectiveness, we have performed extensive experiments on 28 benchmarks from SPEC CPU2006 and two benchmarks from BioBench. Compared with a similar adaptive method, CHAM improves the MLC demand hit rate by 9.2% and an improvement of 1.4% in system performance on average in a single-core system. On a 4-core system, CHAM improves the demand hit rate by 33.06% and improves system performance by 10.1% on average.
Interval Methods in Knowledge Representation
Authors: Kreinovich Vladik
Published: November 2017

Please send your abstracts (or copies of papers that you want to see reviewed here) to vladik@utep.edu, or by regular mail to Vladik Kreinovich, Department of Computer Science, University of Texas at El Paso, El Paso, TX 79968, USA.
Feasibility Analysis of SMA-Based Damping Devices for Use in Seismic Isolation of Low-Rise Frame Buildings
Authors: Qiu Canxing , Tian Li
Published: November 2017

For seismic isolated buildings, the isolators should be able to control peak deformation and have good restoring ability to return the building to its original position. Shape memory alloys (SMAs) are known for their properties of energy dissipation and deformation recovery, which make them appealing for use in isolation systems. To this end, the feasibility of SMA-based damping devices for use in an isolation system of low-rise frame buildings is studied in this paper. Numerical analyses were conducted and compared for buildings installed with SMA-based bearings (SMABs) and lead-rubber bearings (LRBs). A two-mass isolated frame building installed with these bearings was subjected to earthquakes corresponding to multilevel seismic hazards. The results show that the SMABs offer comparable seismic hazard mitigation efficacy to that of the LRBs while successfully restoring the building to the rest position after the earthquake. Furthermore, adding the energy dissipation capacity and properly using the strain hardening behavior of the SMAs are favorable for controlling isolation deformation while protecting the superstructure. The strain hardening behavior of the SMABs is beneficial for controlling deformation at the isolator level, which can still maintain isolation efficacy.