bluuebunny/crossref_metadata_2025 huggingface dataset:
Is nitrogen transfer among plants enhanced by contrasting nutrient‐acquisition strategies?
Authors: TESTE FRANÇOIS P. , VENEKLAAS ERIK J. , DIXON KINGSLEY W. , LAMBERS HANS
Published: May 2014

Nitrogen (N) transfer among plants has been found where at least one plant can fix N2. In nutrient‐poor soils, where plants with contrasting nutrient‐acquisition strategies (without N2 fixation) co‐occur, it is unclear if N transfer exists and what promotes it. A novel multi‐species microcosm pot experiment was conducted to quantify N transfer between arbuscular mycorrhizal (AM), ectomycorrhizal (EM), dual AM/EM, and non‐mycorrhizal cluster‐rooted plants in nutrient‐poor soils with mycorrhizal mesh barriers. We foliar‐fed plants with a K15NO3 solution to quantify one‐way N transfer from ‘donor’ to ‘receiver’ plants. We also quantified mycorrhizal colonization and root intermingling. Transfer of N between plants with contrasting nutrient‐acquisition strategies occurred at both low and high soil nutrient levels with or without root intermingling. The magnitude of N transfer was relatively high (representing 4% of donor plant N) given the lack of N2 fixation. Receiver plants forming ectomycorrhizas or cluster roots were more enriched compared with AM‐only plants. We demonstrate N transfer between plants of contrasting nutrient‐acquisition strategies, and a preferential enrichment of cluster‐rooted and EM plants compared with AM plants. Nutrient exchanges among plants are potentially important in promoting plant coexistence in nutrient‐poor soils.
Soybean resistance to stink bugs (Nezara viridula and Piezodorus guildinii) increases with exposure to solar UV‐B radiation and correlates with isoflavonoid content in pods under field conditions
Authors: ZAVALA JORGE A. , MAZZA CARLOS A. , DILLON FRANCISCO M. , CHLUDIL HUGO D. , BALLARÉ CARLOS L.
Published: May 2014

Solar UV‐B radiation (280–315 nm) has a significant influence on trophic relationships in natural and managed ecosystems, affecting plant–insect interactions. We explored the effects of ambient UV‐B radiation on the levels of herbivory by stink bugs (Nezara viridula and Piezodorus guildinii) in field‐grown soybean crops. The experiments included two levels of UV‐B radiation (ambient and attenuated UV‐B) and four soybean cultivars known to differ in their content of soluble leaf phenolics. Ambient UV‐B radiation increased the accumulation of the isoflavonoids daidzin and genistin in the pods of all cultivars. Soybean crops grown under attenuated UV‐B had higher numbers of unfilled pods and damaged seeds than crops grown under ambient UV‐B radiation. Binary choice experiments with soybean branches demonstrated that stink bugs preferred branches of the attenuated UV‐B treatment. We found a positive correlation between percentage of undamaged seeds and the contents of daidzin and genistin in pods. Our results suggest that constitutive and UV‐B‐induced isoflavonoids increase plant resistance to stink bugs under field conditions.
Plant volatiles and the environment
Authors: LORETO FRANCESCO , DICKE MARCEL , SCHNITZLER JÖRG‐PETER , TURLINGS TED C. J.
Published: May 2014

Volatile organic compounds emitted by plants represent the largest part of biogenic volatile organic compounds (BVOCs) released into our atmosphere. Plant volatiles are formed through many biochemical pathways, constitutively and after stress induction. In recent years, our understanding of the functions of these molecules has made constant and rapid progress. From being considered in the past as a mere waste of carbon, BVOCs have now emerged as an essential element of an invisible language that is perceived and exploited by the plants' enemies, the enemies of plant enemies, and neighbouring plants. In addition, BVOCs have important functions in protecting plants from abiotic stresses. Recent advances in our understanding of the role of BVOC in direct and indirect defences are driving further attention to these emissions. This special issue gathers some of the latest and most original research that further expands our knowledge of BVOC. BVOC emissions and functions in (1) unexplored terrestrial (including the soil) and marine environments, (2) in changing climate conditions, and (3) under anthropic pressures, or (4) in complex trophic communities are comprehensively reviewed. Stepping up from scientific awareness, the presented information shows that the manipulation and exploitation of BVOC is a realistic and promising strategy for agricultural applications and biotechnological exploitations.
Reactive oxygen species, abscisic acid and ethylene interact to regulate sunflower seed germination
Authors: EL‐MAAROUF‐BOUTEAU HAYAT , SAJJAD YASAR , BAZIN JÉRÉMIE , LANGLADE NICOLAS , CRISTESCU SIMONA M. , BALZERGUE SANDRINE , BAUDOUIN EMMANUEL , BAILLY CHRISTOPHE
Published: May 2014

Sunflower (Helianthus annuus L.) seed dormancy is regulated by reactive oxygen species (ROS) and can be alleviated by incubating dormant embryos in the presence of methylviologen (MV), a ROS‐generating compound. Ethylene alleviates sunflower seed dormancy whereas abscisic acid (ABA) represses germination. The purposes of this study were to identify the molecular basis of ROS effect on seed germination and to investigate their possible relationship with hormone signalling pathways. Ethylene treatment provoked ROS generation in embryonic axis whereas ABA had no effect on their production. The beneficial effect of ethylene on germination was lowered in the presence of antioxidant compounds, and MV suppressed the inhibitory effect of ABA. MV treatment did not alter significantly ethylene nor ABA production during seed imbibition. Microarray analysis showed that MV treatment triggered differential expression of 120 probe sets (59 more abundant and 61 less abundant genes), and most of the identified transcripts were related to cell signalling components. Many transcripts less represented in MV‐treated seeds were involved in ABA signalling, thus suggesting an interaction between ROS and ABA signalling pathways at the transcriptional level. Altogether, these results shed new light on the crosstalk between ROS and plant hormones in seed germination.
The “Deliberative Digital Divide:” Opinion Leadership and Integrative Complexity in the U.S. Political Blogosphere
Authors: Brundidge Jennifer , Reid Scott A. , Choi Sujin , Muddiman Ashley
Published: May 2014

This study examined the association between political ideology and linguistic indicators of integrative complexity and opinion leadership in U.S. political blog posts (N = 519). Using Linguistic Inquiry and Word Count (LIWC) text analysis, we found that the posts of conservative bloggers were more integratively simple than those of liberal bloggers. Furthermore, in support of a proposed opinion leadership model of integrative complexity, the relationship between ideology and integrative complexity was mediated by psychological distancing (an indicator of a hierarchical communication style). These findings demonstrate an ideological divide in the extent to which the blogosphere reflects deliberative democratic ideals.
Continuous positive airway pressure is associated with a decrease in pulmonary artery pressure in patients with obstructive sleep apnoea: A meta‐analysis
Authors: Sun Xuefeng , Luo Jinmei , Xiao Yi
Published: May 2014

Pulmonary hypertension has been recognized as being associated with obstructive sleep apnoea (OSA). Continuous positive airway pressure (CPAP) might reduce pulmonary artery pressure in OSA patients; however, evidence from clinical studies is limited and inconsistent. This meta‐analysis aims to assess whether CPAP is associated with a decrease in pulmonary artery pressure in patients with OSA. This systematic review was performed in accordance with the Meta‐analysis of Observational Studies in Epidemiology guidelines. Published studies were identified through a search in MEDLINE, EMBASE and the Cochrane library through to May 2013. Two reviewers sorted papers and extracted data. A random‐effects model was used to combine results across studies comparing pulmonary artery pressure in OSA patients before and after CPAP treatment. Six articles with 181 patients were included in this meta‐analysis, including five before‐after studies and one matched‐control study. The meta‐analysis showed that CPAP was associated with a statistically significant reduction in pulmonary artery pressure in OSA patients (standardized mean difference −1.34, 95% confidence interval: −2.33 to −0.34, P = 0.009). Although this meta‐analysis has some limitations, it indicates that CPAP is associated with a decrease in pulmonary artery pressure in patients with OSA.
Effects of irrigation and nitrogen fertilizer on yield, carbon inputs from above ground harvest residues and soil organic carbon contents of a sandy soil in Germany
Authors: Trost B. , Ellmer F. , Baumecker M. , Meyer‐Aurich A. , Prochnow A. , Drastig K.
Published: May 2014

To better understand the complex interactions between irrigation and nitrogen fertilizer application on soil organic carbon content, the results from long‐term field experiments over a period of 40 years were analysed. The combined effect of irrigation and nitrogen fertilizer rates on crop yields, carbon input by above ground harvest residues and soil organic carbon content has been investigated at a site on a sandy soil in northeast Germany. Combined with nitrogen fertilizer application, irrigation has frequently had a significantly positive effect on crop yield and carbon inputs from above ground harvest residues. However, enhanced carbon inputs to the soil under irrigation did not lead to significantly greater soil organic carbon contents. As the combination of irrigation and nitrogen also improved microbial decomposition by changing of above ground harvest residues C/N ratio and soil moisture, the effect of an additional input of carbon from above ground harvest residues was nullified.
Human herpesvirus 6 reactivation on the 30th day after allogeneic hematopoietic stem cell transplantation can predict grade 2–4 acute graft‐versus‐host disease
Authors: Gotoh M. , Yoshizawa S. , Katagiri S. , Suguro T. , Asano M. , Kitahara T. , Akahane D. , Okabe S. , Tauchi T. , Ito Y. , Ohyashiki K.
Published: May 2014

Background

Viral infections and their occult reactivation occasionally cause not only organ damage, but also exacerbation of acute graft‐versus‐host disease (aGVHD), which may increase transplantation‐related mortality synergistically. To determine correlations between viral reactivation and transplantation‐related complications, we performed various viral screening tests on the 30th day after allogeneic hematopoietic stem cell transplantation (HSCT), and assessed the clinical implications.

Patients and methods

Between August 2007 and January 2013, 49 patients (37 men, 12 women) underwent HSCT in our hospital. The stem cell sources were bone marrow (n = 21), peripheral blood (n = 13), and cord blood (n = 15). The presence of cytomegalovirus (CMV), Epstein–Barr virus (EBV), herpesvirus (HHV) 6, and HHV7 in plasma samples prospectively collected from HSCT recipients on day 30 after HSCT was assayed by quantitative polymerase chain reaction, and the correlations with transplantation‐related complications were evaluated.

Results

The positivities of CMV, EBV, HHV6, and HHV7 were 44.9%, 22.4%, 53.1%, and 18.3%, respectively. We analyzed transplantation‐related complications, and a significant correlation was found only between HHV6 and grade 2–4 aGVHD from day 30 to day 100 (P < 0.001). Using a receiver operating characteristic curve, the area under the curve was calculated as 0.86 (95% confidence interval [CI], 0.74–0.98) between the viral load (VL) of HHV6 and grade 2–4 aGVHD. The sensitivity and specificity were 79% and 93%, respectively, when a cutoff value of 87 copies/mL was used. In multivariate analysis using the Fine and Gray proportional hazards model, the clinically determined high‐risk patients (P = 0.004; hazard ratio [HR], 3.69; 95% CI, 1.52–9.00) and the positivity of HHV6 (P < 0.001; HR, 9.957; 95% CI, 2.68–37.06) were extracted as independent risk factors for the cumulative incidence of grade 2–4 aGVHD on or after post‐HSCT day 30. The only risk factor extracted for the elevation of HHV6 VL >87 copies/mL was cord blood transplantation (P = 0.0032; odds ratio, 7.10; 95% CI, 1.98–30.00).

Conclusion

All of the risk factors previously reported to predict severe aGVHD were obtained only during, but not after, HSCT. Our study suggests that the reactivation of HHV6 (≥87 copies/mL) at 30 days after HSCT is a possible predictive marker for grade 2–4 aGVHD on or after post‐HSCT day 30.
Jehovah's Witnesses and cardiac surgery: a single institution's experience
Authors: McCartney Sharon , Guinn Nicole , Roberson Russell , Broomer Bob , White William , Hill Steven
Published: May 2014

Background

Based on biblical doctrines, patients of the Jehovah's Witness faith refuse allogeneic blood transfusion. Cardiac surgery carries a high risk of blood transfusion, but has been performed in Jehovah's Witnesses for many years. The literature contains information on the outcomes of this cohort, but does not detail the perioperative care of these patients. This article describes a single institution's experience in perioperative care of Jehovah's Witnesses undergoing cardiac surgery.

Study Design and Methods

A chart review of adult Jehovah's Witness patients undergoing cardiac surgery at Duke University between January 2005 and June 2012 was completed. Institutional protocols regarding preoperative erythropoietin (EPO) therapy and intraoperative isovolemic hemodilution are detailed. Patient demographics and use of various blood conservation techniques are described. Hemoglobin (Hb) at various points throughout the perioperative management, hospital length of stay, and mortality are reviewed as indicators of outcome.

Results

Forty‐five Jehovah's Witness patients underwent cardiac surgery at Duke University Medical Center. Preoperative EPO increased the mean Hb by 1.2 g/dL before surgery. Intraoperative normovolemic hemodilution was used in 37 patients with intraoperative mean nadir Hb of 10.3 g/dL. Antifibrinolytics and desmopressin were commonly used as coagulation adjuncts. Mean cardiopulmonary bypass time was 137 minutes, with mean nadir temperature of 30.5°C. The mean length of hospital stay was 6.2 days, with mean intensive care unit stay of 1.7 days. This cohort had zero 90‐day mortality in the perioperative period.

Conclusions

This case series demonstrates that bloodless cardiac surgery can be performed in select patients refusing allogeneic blood transfusion.
Interactions between the tillage system and crop rotation on the crop yield and weed populations under arid conditions
Authors: Sarani Mansoor , Oveisi Mostafa , Mashhadi Hamid Rahimian , Alizade Hassan , Gonzalez‐Andujar Jose Luise
Published: May 2014

Field experiments were conducted in Iran in order to determine the interactions between the tillage system and crop rotation on weed seedling populations and crop yields from 2002 to 2005. No tillage, shallow tillage and deep tillage were the main plots and three crop sequences comprising continuous wheat (W‐W), wheat–canola–wheat–canola (C‐W) and wheat–safflower–wheat–safflower (S‐W) were the subplots. Bromus japonicus, Carthumus lanatus, Polygonum aviculare, Lolium temulentum and Avena ludoviciana were found to be the dominant species. The initial weed population in 2002 was estimated at 65 seedlings per m2 and B. japonicus (∼35 seedlings per m2) was the most abundant species, followed by A. ludoviciana and L. temulentum. The dominant weed species mostly did not favor the combination of S‐W and C‐W with any tillage type. For the B. japonicus population, S‐W in combination with moldboard plowing indicated the lowest seedling population. In conclusion, the crop sequence in combination with tillage would help to control troublesome weed species. Safflower and canola were determined to be effective in reducing the grass weeds. The inclusion of these crops in rotation also increased the total revenue of the cropping systems because of the higher sale price of canola and safflower.
Genetic diversity of the declining arable plant Centaurea cyanus: population fragmentation within an agricultural landscape is not associated with enhanced spatial genetic structure
Authors: Le Corre V , Bellanger S , Guillemin J‐P , Darmency H
Published: May 2014

Agricultural intensification has recently resulted in the decrease in frequency and abundance of arable weed species. This includes the previously widespread Centaurea cyanus, whose populations are now fragmented and infrequent in western Europe. The consequences of habitat modification and fragmentation in terms of genetic diversity of the remaining populations have not yet been addressed. We used ten microsatellite markers to assess the genetic diversity and genetic structure of populations contained in an agricultural landscape in north‐eastern France. The ten microsatellites were all highly polymorphic. Centaurea cyanus appears to be a genetically variable species, with high levels of genetic diversity within each cultivated field. Genetic structure was investigated using a Bayesian method. The partitioning of the genetic variation into three clusters was not associated with sampling locations, and most individuals were admixed. These results suggest that the cornflower populations investigated may have multiple origins in the past and that genetic variation has been reshuffled by human transportation of seeds. Thus, anthropogenic dispersal associated with farming activities is probably a major factor driving the structure of genetic diversity in arable land plants. Despite low levels of genetic differentiation between populations, fine‐scale spatial genetic structure was observed within populations, suggesting limited local dispersal. We conclude that in areas where C. cyanus has become rare, the recent fragmentation of populations may in the future cause a loss of genetic diversity and even extinction.
Quality of healing: Defining, quantifying, and enhancing skeletal muscle healing
Authors: Shin Emily H. , Caterson Edward J. , Jackson Wesley M. , Nesti Leon J.
Published: May 2014

Skeletal muscle injury is common in everyday physical activity and athletics, as well as in orthopedic trauma and disease. The overall functional disability resulting from muscle injury is directly related to the intrinsic healing properties of muscle and extrinsic treatment options designed to maximize repair and/or regeneration of muscle tissue all while minimizing pathologic healing pathways. It is important to understand the injury and repair pathways in order to improve the speed and quality of recovery. Recent military conflicts in Iraq and Afghanistan have highlighted the importance of successfully addressing muscular injury and showed the need for novel treatment options that will maximize functional regeneration of the damaged tissue. These severe, wartime injuries, when juxtaposed to peacetime, sports‐related injuries, provide us with interesting case examples of the two extreme forms of muscular damage. Comparing and contrasting the differences in these healing pathways will likely provide helpful cues that will help physicians recapitulate the near complete repair and regeneration in less traumatic injuries in addition to more severe cases.
Healing of grafted adipose tissue: Current clinical applications of adipose‐derived stem cells for breast and face reconstruction
Authors: Philips Brian J. , Marra Kacey G. , Rubin J. Peter
Published: May 2014

Since their isolation and characterization nearly a decade ago, adipose‐derived stem cells (ASCs) have become one of the most popular adult stem cell populations for soft tissue engineering and regenerative medicine applications. Compared with other stem cell sources, ASCs offer several advantages including abundant autologous source, minor invasive harvesting (liposuction), significant proliferative capacity in culture, and multilineage potential. In this mini review, we focus on some of the more salient published clinical and preclinical data to date regarding ASC treatment for breast and facial soft tissue reconstruction.
The quality of healing: Articular cartilage
Authors: Gomoll Andreas H. , Minas Tom
Published: May 2014

Articular cartilage lacks an intrinsic capacity for self‐repair, and once damaged, it never heals. This creates an opportunity for surgical intervention, whether to stimulate a healing response that results in the formation of a lower‐quality fibrocartilaginous scar or formal cartilage repair in the form of cartilage transplants. This article will review the nature of cartilage injury and discuss indications and techniques for repair.
The cellular and molecular origin of tumor-associated macrophages
Authors: Franklin Ruth A. , Liao Will , Sarkar Abira , Kim Myoungjoo V. , Bivona Michael R. , Liu Kang , Pamer Eric G. , Li Ming O.
Published: May 2014

Long recognized as an evolutionarily ancient cell type involved in tissue homeostasis and immune defense against pathogens, macrophages are being rediscovered as regulators of several diseases, including cancer. Here we show that in mice, mammary tumor growth induces the accumulation of tumor-associated macrophages (TAMs) that are phenotypically and functionally distinct from mammary tissue macrophages (MTMs). TAMs express the adhesion molecule Vcam1 and proliferate upon their differentiation from inflammatory monocytes, but do not exhibit an “alternatively activated” phenotype. TAM terminal differentiation depends on the transcriptional regulator of Notch signaling, RBPJ; and TAM, but not MTM, depletion restores tumor-infiltrating cytotoxic T cell responses and suppresses tumor growth. These findings reveal the ontogeny of TAMs and a discrete tumor-elicited inflammatory response, which may provide new opportunities for cancer immunotherapy.
Reaching the magnetic anisotropy limit of a 3
d
metal atom
Authors: Rau Ileana G. , Baumann Susanne , Rusponi Stefano , Donati Fabio , Stepanow Sebastian , Gragnaniello Luca , Dreiser Jan , Piamonteze Cinthia , Nolting Frithjof , Gangopadhyay Shruba , Albertini Oliver R. , Macfarlane Roger M. , Lutz Christopher P. , Jones Barbara A. , Gambardella Pietro , Heinrich Andreas J. , Brune Harald
Published: May 2014

Maximizing atomic magnetic memory

A study of the magnetic response of cobalt atoms adsorbed on oxide surfaces may lead to much denser storage of data. In hard drives, data are stored as magnetic bits; the magnetic field pointing up or down corresponds to storing a zero or a one. The smallest bit possible would be a single atom, but the magnetism of a single atom —its spin—has to be stabilized by interactions with heavy elements or surfaces through an effect called spin-orbit coupling. Rau
et al.
(see the Perspective by Khajetoorians and Wiebe) built a model system in pursuit of single-atom bits—cobalt atoms adsorbed on magnesium oxide. At temperatures approaching absolute zero, the stabilization of the spin's magnetic direction reached the maximum that is theoretically possible.

Science
, this issue p.
988
; see also p.
976
Complete Genome Sequences of Lactobacillus johnsonii Strain N6.2 and Lactobacillus reuteri Strain TD1
Authors: Leonard Michael T. , Valladares Ricardo B. , Ardissone Alexandria , Gonzalez Claudio F. , Lorca Graciela L. , Triplett Eric W.
Published: May 2014

We report here the complete genome sequences of
Lactobacillus johnsonii
strain N6.2, a homofermentative lactic acid intestinal bacterium, and
Lactobacillus reuteri
strain TD1, a heterofermentative lactic acid intestinal bacterium, both isolated from a type 1 diabetes-resistant rat model.
Draft Genome Sequence of Lactobacillus sucicola JCM 15457
T
, a Motile Lactic Acid Bacterium Isolated from Oak Sap
Authors: Irisawa Tomohiro , Oshima Kenshiro , Suda Wataru , Kitahara Maki , Sakamoto Mitsuo , Kitamura Keiko , Iida Toshiya , Hattori Masahiro , Ohkuma Moriya
Published: May 2014

Here, we report the draft genome sequence of a motile lactic acid bacterium,
Lactobacillus sucicola
JCM 15457
T
, isolated from oak sap. Motility-related genes and their organization in the annotated genome were broadly similar to those in the sequenced genomes of related lactobacilli.
Yeast Identification by DNA Sequencing in an Undergraduate Mycology Laboratory
Authors: Safranek William W.
Published: May 2014

A yeast identification procedure based on the sequencing of the D1/D2 region of the yeast 26S ribosomal DNA was presented in an undergraduate general mycology laboratory. Extracted genomic DNA of environmental yeasts collected by the students was used to PCR-amplify the D1/D2 region of the isolates. Agarose gel electrophoresis confirmed the presence of the expected amplicon which was purified for sequencing by a spincolumn method then submitted to a commercial sequencing laboratory. The students examined the sequence of their isolates for base miscalls using Applied Biosytem’s Sequence Scan program. The sequences were then used to perform a BLAST search which compared them to the D1/D2 sequences of all validly described yeast species on file in the GenBank database. Of 37 isolates tested, 33 (89%) returned usable sequences for BLAST identification. The module required two lab periods of 1.5 and 2 hours, respectively, to complete with an enrollment of 40 students.
Undergraduate Urban Metagenomics Research Module
Authors: Muth Theodore R. , McEntee Catherine M.
Published: May 2014

The undergraduate urban metagenomics research module is an adaptable and tractable project that can be incorporated into exisiting microbiology, ecology, bioinformatics, introductory biology or other courses. The module takes advantage of recent advances in metagenomics and next generation sequencing, giving students an opportunity to apply these current technologies to novel questions regarding microbial community diversity and dynamics.
Engaging Allied-Health Students with Virtual Learning Environment Using Course Management System Tutorial Site
Authors: Nguyen Andrew , Tawde Mangala
Published: May 2014

Human Anatomy and Physiology I and II are major gateway courses into nursing and other health related sciences careers. Being a New York City community college, the students at Queensborough Community College are highly diverse not only in their ethnic and cultural background, but also in the levels of preparedness. When they take Human Anatomy-Physiology I as the first pre-requisite class, many are either freshman or returning students after a hiatus. Many students lack formal training in Science or Biology and are overwhelmed by the depth and immensity of the material presented in above courses. Though the enrollment for these classes is heavy; above factors lead to high attrition rates. However one common feature of this new generation of students is their access and familiarity to the internet, digital technology and other techno gadgets such as smart phones, tablets, etc. Though it is hard for us to accept, it is a fact that today’s generation of students (generation Y) is more techno savvy and these gadgets engage (or distract) them more than books. This indicated a clear need for developing alternatives to traditional teaching methods to engage students of an urban community college setting. We decided to investigate if a web-based supplemental tutorial would help engage these students and thus help them build their course knowledge base to improve their academic performance.
Two Laboratory Activities Using Conventional or Real-Time PCR to Simulate Pathogenic
E. coli
Detection
Authors: Klein Joanna R.
Published: May 2014

In these lab activities, students perform conventional PCR and real-time PCR to simulate pathogenic
E. coli
detection. The labs were designed to complement a previously published virtual PCR classroom activity in which students are asked to design a PCR-based diagnostic test for a pathogenic strain of
E. coli.
In the virtual PCR activity, students use bioinformatics to discover that the Shiga toxin genes (
stx1
and
stx2
) are unique to the Enterohemorrhagic
E. coli
(EHEC) strain O157:H7. Thus they come to the conclusion that doing PCR with primers designed for shiga toxin should be able to differentiate O157:H7 from other strains of
E. coli.
In the lab activity described here, students actually perform the PCR assay. Performing PCR enhanced student understanding of the technique beyond what was accomplished through the virtual PCR classroom activity and is recommended as an addition to the case study.
Reflections on the Value of Mapping the Final Theory Examination in a Molecular Biochemistry Unit
Authors: Eri Rajaraman , Cook Anthony , Brown Natalie
Published: May 2014

This article assesses the impact of examination mapping as a tool to enhancing assessment and teaching quality in a second-year biochemistry unit for undergraduates. Examination mapping is a process where all questions in a written examination paper are assessed for links to the unit’s intended learning outcomes. We describe how mapping a final written examination helped visualise the impact of the assessment task on intended learning outcomes and skills for that biochemistry unit. The method involved complete analysis of all the final examination questions, and linking each question to task-specific criteria or learning outcomes. This strategy also identified the distribution of marks to key learning outcomes such as knowledge, interpretation and application. Our results indicated that 45% of the questions addressed the knowledge aspect while 37% and 18% were allocated to interpretation and application facets of the intended learning outcomes respectively. In addition, our exam mapping strategy aided in defining the characteristics of examination questions. The examination mapping exercise proved to be a useful process that can enhance a balanced assessment of skills in addition to devising strategies such as criterion-referenced assessment for examinations.
Bacterial Monologue: An Engaging Writing Activity for Nonscience Majors
Authors: Song Pengfei
Published: May 2014

The anthropocentric focus of microbiology has painted a negative image of the largely unknown bacterial community, when in reality bacteria play many more significant roles than influencing human health. It is important to convey this message to college students so that they can make informed decisions as an educated citizen. Non-major students taking a microbiology course however, may demonstrate poor interest and become further alienated by the abstract terminologies. Recent studies suggest that story writing may enhance scientific literacy, and role-play activities are effective means to engage students. Here, I combine these two strategies and introduce a writing activity in which students impersonate an assigned bacterium. Through this writing exercise, students demonstrated deeper understanding of key concepts in microbiology, greater appreciation of the broad roles of bacteria, and improved attitude towards science and science learning.
A Guide to Understanding the Science behind Useful Approaches to LearningReview of:	The New Science of Learning: How to Learn in Harmony With Your Brain;	DoyleTerry and	ZakrajsekTodd; (	2013).	Stylus Publishing,	Sterling, VA.	126 pages.
Authors: Dewsbury Bryan M.
Published: May 2014

Review of:
The New Science of Learning: How to Learn in Harmony With Your Brain;
Terry Doyle and Todd Zakrajsek; (2013). Stylus Publishing, Sterling, VA. 126 pages.
Less experience and running pace are potential risk factors for medical complications during a 56 km road running race: a prospective study in 26 354 race starters—SAFER study II
Authors: Schwabe Karen , Schwellnus Martin P , Derman Wayne , Swanevelder Sonja , Jordaan Esme
Published: May 2014

Background

It is important to identify risk factors associated with medical complications during ultra-marathons so that prevention programmes can be developed.

Objective

To determine risk factors for medical complications during ultra-marathons.

Design

Prospective study.

Setting

Two Oceans ultra-marathon (56 km) races.

Participants

26 354 race starters.

Methods

Medical complications (defined as any runner requiring assessment by a doctor at the race medical facility or a local hospital on race day) were recorded over 4 years. Complications were subdivided according to the system that was affected and by final diagnosis. A Poisson regression model was used to determine risk factors for any medical complication and for more common specific complications.

Results

Risk factors for medical complications during 56 km road races were less running experience (≤1 medal vs 2–4 medals, p=0.0097), and both fastest (<6 vs 6–7 min/km, p=0.0051) and slowest (>7 vs 6–7 min/km, p<0.0001) running pace category. Year of observation was also associated with risk of complications (2009 vs 2008, p=0.0176; 2009 vs 2010, p=0.0007; 2010 vs 2011, p=0.0112). Risk factors for specific common medical complications were: postural hypotension (slowest pace), serious exercise-associated muscle cramping (older age, fastest pace), gastrointestinal complications (slowest pace) and dermatological complications (fastest pace).

Conclusions

Less experience and running at either a slow or a fast pace were risk factors for complications during 56 km road running. Annual variation may also affect risk. Risk factors for specific medical complications were also identified. These data form the basis of further studies to assist medical staff to plan appropriate care at races.
The clinical relevance and newsworthiness of NIHR HTA-funded research: a cohort study
Authors: Wright D , Young A , Iserman E , Maeso R , Turner S , Haynes R B , Milne R
Published: May 2014

Objective

To assess the clinical relevance and newsworthiness of the UK National Institute for Health Research (NIHR)Health Technology Assessment(HTA) Programme funded reports.

Study design

Retrospective cohort study.

Setting

The cohort included 311 NIHR HTA Programme funded reports publishing inHTAin the period 1 January 2007–31 December 2012. The McMaster Online Rating of Evidence (MORE) system independently identified the clinical relevance and newsworthiness of NIHR HTA publications and non-NIHR HTA publications. The MORE system involves over 4000 physicians rating publications on a scale of relevance (the extent to which articles are relevant to practice) and a scale of newsworthiness (the extent to which articles contain news or something clinicians are unlikely to know).

Main outcome measures

The proportion of reports published inHTAmeeting MORE inclusion criteria and mean average relevance and newsworthiness ratings were calculated and compared with publications from the same studies publishing outsideHTAand non-NIHR HTA funded publications.

Results

286/311 (92.0%) of NIHR HTA reports were assessed by MORE, of which 192 (67.1%) passed MORE criteria. The average clinical relevance rating for NIHR HTA reports was 5.48, statistically higher than the 5.32 rating for non-NIHR HTA publications (mean difference=0.16, 95% CI 0.04 to 0.29, p=0.01). Average newsworthiness ratings were similar between NIHR HTA reports and non-NIHR HTA publications (4.75 and 4.70, respectively; mean difference=0.05, 95% CI −0.18 to 0.07, p=0.402). NIHR HTA-funded original research reports were statistically higher for newsworthiness than reviews (5.05 compared with 4.64) (mean difference=0.41, 95% CI 0.18 to 0.64, p=0.001).

Conclusions

Funding research of clinical relevance is important in maximising the value of research investment. The NIHR HTA Programme is successful in funding projects that generate outputs of clinical relevance.
Testing the feasibility and acceptability of using the Nintendo Wii in the home to increase activity levels, vitality and well-being in people with multiple sclerosis (Mii-vitaliSe): protocol for a pilot randomised controlled study
Authors: Thomas Sarah , Fazakarley Louise , Thomas Peter W , Brenton Sarah , Collyer Sarah , Perring Steve , Scott Rebecca , Galvin Kathleen , Hillier Charles
Published: May 2014

Introduction

The benefits of physical activity for people with multiple sclerosis (pwMS) have been recognised. However, exercise regimens can be difficult to maintain over the longer term and pwMS may face unique barriers to physical activity engagement. Pilot research suggests the Nintendo Wii can be used safely at home by pwMS with minimal mobility/balance issues and may confer benefits. We have developed a home-based physiotherapist supported Wii intervention (‘Mii-vitaliSe’) for pwMS that uses commercial software. This is a pilot study to explore the feasibility of conducting a full scale clinical and cost-effectiveness trial of Mii-vitaliSe.

Methods and analysis

30 ambulatory, relatively inactive pwMS will be randomised to receive Mii-vitaliSe immediately, or after 6 months. Outcomes, measured at baseline and 6 and 12 months later, will include balance, gait, mobility, hand dexterity and self-reported physical activity levels, fatigue, self-efficacy, mood and quality of life. Interviews conducted on a purposive sample of participants will explore experiences of participation in the study and barriers and facilitators to using the Wii. Mean recruitment, adherence rate and standard deviations (SDs) of potential primary outcomes for the full trial will be estimated and precision summarised using 95% confidence intervals (CIs). Interview transcripts will be thematically analysed using a generic qualitative approach.

Ethics and dissemination

National Health Service (NHS; ref 12/SC/0420) and university ethical approvals have been obtained as has NHS Research and Development permission from the relevant trust. A home risk assessment will be undertaken for all potential participants. All adverse events will be closely monitored, documented and reported to the study Safety Monitoring Committee. At least one publication in a peer reviewed journal will be produced and research findings presented at a national and international conference. With service users, we will coproduce a summary of the findings for dissemination on our research unit's website and elsewhere.

Trial registration number

ISRCTN 49286846.
Interventions employed to improve intrahospital handover: a systematic review
Authors: Robertson Eleanor R , Morgan Lauren , Bird Sarah , Catchpole Ken , McCulloch Peter
Published: May 2014

Background

Modern medical care requires numerous patient handovers/handoffs. Handover error is recognised as a potential hazard in patient care, and the information error rate has been estimated at 13%. While accurate, reliable handover is essential to high quality care, uncertainty exists as to how intrahospital handover can be improved. This systematic review aims to evaluate the effectiveness of interventions aimed at improving the quality and/or safety of the intrahospital handover process.

Methods

We searched for articles on handover improvement interventions in EMBASE, MEDLINE, HMIC and CINAHL between January 2002 and July 2012. We considered studies of: staff knowledge and skills, staff behavioural change, process change or patient outcomes.

Results

631 potentially relevant papers were identified from which 29 papers were selected for inclusion (two randomised controlled trials and 27 uncontrolled studies). Most studies addressed shift-change handover and used a median of three outcome measures, but there was no outcome measure common to all. Poor study design and inconsistent reporting methods made it difficult to reach definite conclusions. Information transfer was improved in most relevant studies, while clinical outcome improvement was reported in only two of 10 studies. No difference was noted in the likelihood of success across four types of intervention.

Conclusions

The current literature does not confirm that any methodology reliably improves the outcomes of clinical handover, although information transfer may be increased. Better study designs and consistency of the terminology used to describe handover and its improvement are urgently required.
Recovery of pituitary function following treatment of an unruptured giant cavernous carotid aneurysm using Surpass flow-diverting stents
Authors: Tan Lee A , Sandler Victoria , Todorova-Koteva Kristina , Levine Laurence , Lopes Demetrius K , Moftakhar Roham
Published: May 2014

Giant aneurysms arising from the cavernous internal carotid artery (ICA) can mimic pituitary adenomas and may cause pituitary dysfunction due to their mass effect on the pituitary gland. We report a case of a 56-year-old man presenting with impotence, fatigue and panhypopituitarism who was found to have a giant unruptured aneurysm arising from the right cavernous ICA with severe mass effect on the pituitary gland. The patient underwent endovascular treatment of the giant aneurysm using two telescoping Surpass flow-diverting stents. At 6-month follow-up, repeat cerebral angiography showed Raymond grade II occlusion of the aneurysm with a small neck remnant. At the 10-month follow-up the patient showed full recovery of his pituitary function and clinical resolution of impotence and fatigue. This is the first report of occlusion of a giant cavernous carotid aneurysm using next generation Surpass flow-diverting stents leading to complete recovery of pituitary function.
Predicting the resistance profile of a spudcan penetrating sand overlying clay
Authors: Hu Pan , Wang Dong , Cassidy Mark J. , Stanier Sam A.
Published: May 2014

Assessment of the risk of punch-through failure of spudcan foundations on sand overlying clay requires prediction of the full penetration resistance profile, from touchdown and through punch-through to equilibrium of the vertical resistance at depth in the underlying clay layer. This study uses the Coupled Eulerian–Lagrangian approach, a large deformation finite element analysis method, to model the complete penetration resistance profile of a spudcan on sand overlying clay. The sand is modeled using the Mohr–Coulomb model, while the clay is modeled using a modified Tresca model to account for strain softening. The numerical method is then used to simulate a series of spudcan penetration tests, performed in a geotechnical centrifuge, on medium dense sand overlying clay. The punch-through behavior observed in the experiments is replicated, and the penetration resistance profiles from numerical analyses are generally a reasonable match to the experimental measurements. The influences of the sand layer height to foundation diameter ratio, sand–clay interface shear strength, and strength gradient in clay on the penetration resistance profiles are explored in a complementary parametric study. The penetration resistance in the underlying clay layer is well predicted using a simple linear expression for the bearing capacity factor for the spudcan and underlying sand plug. This expression is combined with an existing failure stress dependent model for predicting peak resistance to form a simplified method for prediction of the full penetration resistance profile. This new method provides estimates of the vertical penetration that the spudcan will run during the punch-through event. It is validated against both medium dense and dense sand centrifuge tests.
Electron scattering on the short-range potential of the crystal lattice defects in ZnO
Authors: Malyk O.P.
Published: May 2014

The processes of electron scattering on a short-range potential caused by interaction with polar and nonpolar optical phonons, piezoelectric and acoustic phonons, static strain, and neutral and ionized impurities in wurtzite n-ZnO with impurity concentration ∼1 × 1017 cm−3 are considered. The temperature dependences of electron mobility and Hall factor in the range 15/550 K are calculated.
Daytime declines in rumen–reticulum fill of male white-tailed deer (Odocoileus virginianus) from south Texas
Authors: Aiken M.R.E. , Duarte A. , Luna R.S. , Wolcott D.M. , Weckerly F.W.
Published: May 2014

Understanding rumen–reticulum fill dynamics gives us insight into how environmental conditions influence animal behaviors that affect when animals access forage. We examined whether there were daytime declines in rumen–reticulum fill in response to high ambient temperatures in free-ranging white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) on a diurnal scale. We hypothesized that to reduce heat-producing digestive processes in the heat of the day, rumen–reticulum fill and digestion in the rumen–reticulum would decline throughout the day. We collected the rumina and reticula of adult males and females across 30 h in two autumns in south Texas, USA. We also measured dry digesta mass, organ mass, and crude protein and acid detergent fiber concentrations of rumen–reticulum contents. In males, dry digesta mass declined throughout the day and crude protein concentrations were greatest when wet digesta and organ mass were the largest. Additionally, declines in dry digesta and wet digesta mass coincided with declines in crude protein concentrations and organ mass. Females did not display declines in rumen–reticulum fill (wet mass). Females were probably less vulnerable to heat than males because of their smaller body size. Male white-tailed deer foraged primarily during the cooler nights to reduce foraging and digestion during the heat of the day.
MULTISERVER RETRIAL QUEUES WITH TWO TYPES OF NONPERSISTENT CUSTOMERS
Authors: PHUNG-DUC TUAN
Published: May 2014

We consider M/M/c/K(K ≥ c ≥ 1) retrial queues with two types of nonpersistent customers, which are motivated from modeling of service systems such as call centers. Arriving customers that see the system fully occupied either join the orbit or abandon receiving service forever. After an exponentially distributed time in the orbit, each customer either abandons the system forever or retries to occupy a server again. For the case of K = c = 1, we present an analytical solution for the generating functions in terms of confluent hypegeometric functions. In the general case, the number of customers in the system and that in the orbit form a level-dependent quasi-birth-and-death (QBD) process whose structure is sparse. Based on this sparse structure, we develop a numerically stable algorithm to compute the joint stationary distribution. We show that the computational complexity of the algorithm is linear to the capacity of the queue. Furthermore, we present a simple fixed point approximation model for the case where the algorithm is time consuming. Numerical results show various insights into the system behavior.
Electrical and magnetic transport properties of Co-doped Bi2Se3 topological insulator crystals
Authors: Zhang Min , Lv Li , Wei Zhantao , Yang Liqin , Yang Xinsheng , Zhao Yong
Published: May 2014

Transition metal doped topological insulators (TI) Co x Bi 2-x Se 3 were prepared and the phase structure, electrical and magnetic transport properties, Hall mobility and Hall resistivity were studied. The lattice constant c decreased with the increasing Co concentration. All samples exhibited weak metallic resistivity. With increasing Co concentration, the value of ρxx increased, reaching a maximum at x = 0.02, and then decreased. The resistivity data could be fitted by different formulas below and above 30 K in all samples result from different mechanism corresponding to different temperature regions. The magnetoresistance (MR) of Bi 2 Se 3 TI showed a change dependence of concentration. The MR was enhanced by small quantity of Co doping, attaining a maximum value in Bi 1.98 Co 0.02 Se 3 crystal; but MR was suppressed in high-doped sample (x > 0.02). Those results were ascribed to the rivalry between the phonon scattering effect and the magnetic ordering in single crystals caused by Co ions. For low-doped samples doped, the contribution of phonon scattering was much higher than that of magnetic ordering, leading to larger MR value. However, in samples doped with higher Co concentrations, the magnetic ordering effect became dominant and caused the MR decreases. The MR increased with decreasing temperature and increasing magnetic field. The Hall mobility data indicated that incorporating Co in Bi 2 Se 3 single crystal can reduce native defect of Bi 2 Se 3.