bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of reports of missed nursing care: Registered Nurses vs. practical nurses in hospitals
Authors: Bragadóttir Helga , Kalisch Beatrice J.
Published: March 2018

Background

Missed nursing care is an error of omission defined as standard, required nursing care that is not completed or is seriously delayed. Study findings from around the world show that missed nursing care is a global concern.

Purpose

The purpose of this study was to compare reports of missed nursing care by two types of nurses – registered nurses and practical nurses – in acute care hospitals in Iceland. Former studies in theUSAindicate a variance in reports of missed nursing care by staff with different roles.

Methods

This was a cross‐sectional descriptive study using theMISSCARESurvey‐Icelandicquestionnaire for data collection. The questionnaire asks about the amount of missed nursing care on the unit for 24 nursing elements (Part A) and 17 reasons of care being missed (Part B). Participants were nursing staff from medical, surgical and intensive care units in all hospitals in Iceland.

Findings

At‐test for independent groups showed a significant difference for the overall missed nursing care score (Part A) between registered nurses (M= 2.09,SD= 0.51) and practical nurses (M= 1.82,SD= 0.59) [t(541) = 5.703, p < 0.001]. A comparison of the overall mean score for reasons of missed nursing care (Part B) between registered nurses (M= 2.32,SD= 0.38) and practical nurses (M= 2.21,SD= 0.62) indicated a significant difference in their reporting [t(299) = 2.210, p = 0.028]. In spite of the overall significant difference in ratings of the elements and reasons for missed nursing care by registered nurses and practical nurses, a pattern is evident in the ranking of the elements of nursing care being missed and reasons.

Conclusions

The findings of this study point to the need to acknowledge certain aspects of missed nursing care and the different roles within nursing. They indicate a need to improve open, sincere and structured communication and mutual respect and trust within healthcare teams in Icelandic hospitals.
Provenance of the great Cambrian sandstone succession of northern Gondwana unravelled by strontium, neodymium and lead isotopes of feldspars and clays
Authors: Ben Dor Yoav , Harlavan Yehudit , Avigad Dov
Published: March 2018

The great Cambro–Ordovician sandstone succession of northern Gondwana is one of the most voluminous siliciclastic deposits on Earth. Its deposition took place following the Neoproterozoic Pan‐African Orogeny and the consolidation of Gondwana, a crucial episode in Earth history. Its provenance is of great importance for reconstructing palaeogeographic and tectonic settings and determining sediment dispersal patterns. In Israel and its environs, Palaeozoic sandstones overlie the juvenile Neoproterozoic basement of the Arabian–Nubian Shield. These basement rocks were considered as an important sediment source to the Cambro–Ordovician succession. However, recent studies established that a dominant portion of detrital zircons in the succession was derived from Archean–Proterozoic remobilized terranes, suggesting transportation distances of thousands of kilometres beyond the Arabian–Nubian Shield, and thus question the provenance of other, less weathering‐resistant constituents, which were not necessarily derived from the same localities. Feldspars and clays were separated from 13 samples and analyzed for mineralogical and geochemical compositions, strontium, neodymium and lead isotopes, in order to further constrain the provenance of the Cambro–Ordovician succession of northern Gondwana. Detrital feldspars have εNd values significantly different from feldspars of the Arabian–Nubian Shield, ranging from −8 to −14, with model ages of 950 to 1750 Ma, more radiogenic lead compositions, and μ (238U/204Pb) values ranging from 9·8 to 10·26. Clays are dominated by illite, smectite and kaolinite, with εNd values ranging between −14 and −9, with 87Sr/86Sr ratios up to 0·757. These findings point to a significant contribution of remote ancient terranes from outside the Arabian–Nubian Shield to the Cambro–Ordovician sandstone of northern Gondwana. The possible sources for these sediments are the Saharan Metacraton and the southern regions of the East African Orogen.
An Empirical Test of the Three‐Step Theory of Suicide in U.K. University Students
Authors: Dhingra Katie , Klonsky E. David , Tapola Vojna
Published: March 2018

The purpose of this study was to further our understanding of how individuals move down the pathway from first thinking about suicide to ultimately attempting to take their own lives by empirically testing the Three‐Step Theory (3ST) in a sample of university students (n = 665). Results largely support the theory's central propositions. First, an interactive model of pain and hopelessness accounted for substantial variance in suicidal desire. This result replicated in both men and women, and across age groups (i.e., below 35 and at or above 35). Also, as predicted, connectedness was protective against ideation in those high on both pain and hopelessness. However, contrary to our prediction, connectedness was similarly protective among everyone else. Finally, suicide capacity predicted suicide attempt history over and above current and lifetime suicide ideation. These findings provide further support to the 3ST.
Differences in in vivo muscle fascicle and tendinous tissue behavior between the ankle plantarflexors during running
Authors: Lai A. K. M. , Lichtwark G. A. , Schache A. G. , Pandy M. G.
Published: March 2018

The primary human ankle plantarflexors, soleus (SO), medial gastrocnemius (MG), and lateral gastrocnemius (LG) are typically regarded as synergists and play a critical role in running. However, due to differences in muscle‐tendon architecture and joint articulation, the muscle fascicles and tendinous tissue of the plantarflexors may exhibit differences in their behavior and interactions during running. We combined in vivo dynamic ultrasound measurements with inverse dynamics analyses to identify and explain differences in muscle fascicle, muscle‐tendon unit, and tendinous tissue behavior of the primary ankle plantarflexors across a range of steady‐state running speeds. Consistent with their role as a force generator, the muscle fascicles of the uniarticular SO shortened less rapidly than the fascicles of the MG during early stance. Furthermore, the MG and LG exhibited delays in tendon recoil during the stance phase, reflecting their ability to transfer power and work between the knee and ankle via tendon stretch and storage of elastic strain energy. Our findings add to the growing body of evidence surrounding the distinct mechanistic functions of uni‐ and biarticular muscles during dynamic movements.
Relations between parenting and adolescent's attachment in families differing in solidarity patterns
Authors: Lubiewska Katarzyna , Albert Isabelle , Trommsdorff Gisela , Friedlmeier Wolfgang
Published: March 2018

To explain attachment development in adolescence in different contexts we applied the family solidarity model (e.g., Bengtson, 2001 generally used to analyze intergenerational adult children‐elderly parents relations. The model differentiates four family solidarity patterns which were assumed in our study to occur in adolescent–parent relations, though with a different distribution. We tested a susceptibility hypothesis assuming that effects of parenting will be stronger in family patterns with higher, compared with lower, affectual solidarity. A sample of Polish adolescents, their mothers (N = 570, both), and their fathers (N = 290) was surveyed as part of the Value‐of‐Children‐Study (Trommsdorff & Nauck, 2005). Four family patterns were identified: highly affectual amicable and harmonious; and less affectual and most frequently displayed detached and disharmonious patterns. The parenting susceptibility hypothesis was supported: For amicable and harmonious families, adolescents’ perception of maternal rejection was more strongly related with their attachment compared with the other family types. Partly in line with our hypothesis, effects of paternal rejection on adolescents’ attachment were strongest in amicable families, however, not significant in harmonious families. The study demonstrates that the relation between parenting on adolescents’ attachment representation is influenced by the pattern of family parents–child relations.
Formative assessment and the role of teachers' content area
Authors: Lyon Christine Jennifer , Wylie Elizabeth Caroline , Brockway Debra , Mavronikolas Elia
Published: March 2018

Professional development (PD) programs focused on increasing teachers' use of formative assessment generally provide a framework designed to help teachers understand the breadth and complexity of formative assessment, while advocating for teacher choice with respect to the specific implementation. This study examined the implementation patterns of 82 high school mathematics and science teachers to understand whether implementation approaches differed by content area. Results suggested that mathematics and science teachers significantly increased their self‐reported practice of formative assessment, in similar ways; however, the specific approaches that mathematics and science teachers chose to operationalize on a daily basis differed. These findings have implications for the design of PD and future research efforts.
Veteran‐centred content in medical education
Authors: Ross Paula T , Lypson Monica L
Published: March 2018

Background

Veterans have unique experiences that warrant special consideration in health care. Unfortunately, training in veteran‐centred care has not been a clear focus of medical education, and only a very small proportion of medical schools include military cultural competency in their curricula.

Methods

We conducted an 80‐minute focus group with six US veterans. Open‐ended questions were used to elicit their perceptions of the health care that they receive, and how it can be improved. The audio‐recording was transcribed verbatim and coded for thematic content. A phenomenological analytic approach was used to analyse the 31‐page transcript and arrive at the final themes.

Results

Former service members from various periods of conflict (e.g. World War II, Vietnam, Persian Gulf) offered key insights about how to improve veterans’ health care experiences. Veterans suggested that consideration of their previous military service would improve care. They lamented that the lack of military consciousness is a barrier to care. Finally, they suggested that clinicians pay close attention to the transition from service member to civilian, as reintegration to civilian life is a critical life experience.

Training in veteran‐centred care has not been a clear focus of medical education

Discussion

Veteran‐centred care ensures optimal health care through ease of access to services, and through positive patient–provider interactions. Being aware of military culture can help providers to contextualise veterans’ experiences and beliefs about health care seeking and illness management, particularly for invisible wounds of war, including traumatic brain injury (TBI) and post‐traumatic stress disorder (PTSD).
Aspergillus flavus native valve endocarditis following combined liver and renal transplantation: Case report and review of the literature
Authors: Alsobayeg Sultan , Alshehri Nada , Mohammed Shamayel , Fadel Bahaa M. , Omrani Ali S. , Almaghrabi Reem S.
Published: March 2018

Aspergillus endocarditis is a rare infection that occurs most commonly in patients with prior cardiac surgery but cases in post‐transplant recipients without prior cardiac surgery have been reported. Diagnosis is often delayed and requires high index of suspicion. We here report a case of Aspergillus endocarditis in solid organ transplant recipient.
Re‐infection of Toxoplasma gondii after HSCT presenting lymphadenopathy resembling recurrence of lymphoma
Authors: Hashiguchi Junichi , Onozawa Masahiro , Naka Tomoaki , Hatanaka Kanako C. , Shiratori Souichi , Sugita Junichi , Fujimoto Katsuya , Matsuno Yoshihiro , Teshima Takanori
Published: March 2018

Toxoplasma gondii (T. gondii) reactivation is one of the fatal complications after hematopoietic stem cell transplantation (HSCT); however, re‐infection has not been reported. Here, we report a case of mycosis fungoides in which cervical lymphadenopathy developed after HSCT. Initially, recurrent lymphoma was suspected. However, biopsy of the lymph node showed typical histology of toxoplasmosis and serology showed re‐infection of T. gondii. Toxoplasmosis needs to be differentiated for cases with lymphoadenopthy after HSCT.
GreenCut protein CPLD49 of Chlamydomonas reinhardtii associates with thylakoid membranes and is required for cytochrome b6f complex accumulation
Authors: Wittkopp Tyler M. , Saroussi Shai , Yang Wenqiang , Johnson Xenie , Kim Rick G. , Heinnickel Mark L. , Russell James J. , Phuthong Witchukorn , Dent Rachel M. , Broeckling Corey D. , Peers Graham , Lohr Martin , Wollman Francis‐André , Niyogi Krishna K. , Grossman Arthur R.
Published: March 2018

The GreenCut encompasses a suite of nucleus‐encoded proteins with orthologs among green lineage organisms (plants, green algae), but that are absent or poorly conserved in non‐photosynthetic/heterotrophic organisms. In Chlamydomonas reinhardtii, CPLD49 (Conserved in Plant Lineage and Diatoms49) is an uncharacterized GreenCut protein that is critical for maintaining normal photosynthetic function. We demonstrate that a cpld49 mutant has impaired photoautotrophic growth under high‐light conditions. The mutant exhibits a nearly 90% reduction in the level of the cytochrome b6f complex (Cytb6f), which impacts linear and cyclic electron transport, but does not compromise the ability of the strain to perform state transitions. Furthermore, CPLD49 strongly associates with thylakoid membranes where it may be part of a membrane protein complex with another GreenCut protein, CPLD38; a mutant null for CPLD38 also impacts Cytb6f complex accumulation. We investigated several potential functions of CPLD49, with some suggested by protein homology. Our findings are congruent with the hypothesis that CPLD38 and CPLD49 are part of a novel thylakoid membrane complex that primarily modulates accumulation, but also impacts the activity of the Cytb6f complex. Based on motifs of CPLD49 and the activities of other CPLD49‐like proteins, we suggest a role for this putative dehydrogenase in the synthesis of a lipophilic thylakoid membrane molecule or cofactor that influences the assembly and activity of Cytb6f.
Regulation of early endosomes across eukaryotes: Evolution and functional homology of Vps9 proteins
Authors: Herman Emily K. , Ali Moazzam , Field Mark C. , Dacks Joel B.
Published: March 2018

Endocytosis is a crucial process in eukaryotic cells. The GTPases Rab 5, 21 and 22 that mediate endocytosis are ancient eukaryotic features and all available evidence suggests retained conserved function. In animals and fungi, these GTPases are regulated in part by proteins possessing Vps9 domains. However, the diversity, evolution and functions of Vps9 proteins beyond animals or fungi are poorly explored. Here we report a comprehensive analysis of the Vps9 family of GTPase regulators, combining molecular evolutionary data with functional characterization in the non‐opisthokont model organism Trypanosoma brucei. At least 3 subfamilies, Alsin, Varp and Rabex5 + GAPVD1, are found across eukaryotes, suggesting that all are ancient features of regulation of endocytic Rab protein function. There are examples of lineage‐specific Vps9 subfamily member expansions and novel domain combinations, suggesting diversity in precise regulatory mechanisms between individual lineages. Characterization of the Rabex5 + GAPVD1 and Alsin orthologues in T. brucei demonstrates that both proteins are involved in endocytosis, and that simultaneous knockdown prevents membrane recruitment of Rab5 and Rab21, indicating conservation of function. These data demonstrate that, for the Vps9‐domain family at least, modulation of Rab function is mediated by evolutionarily conserved protein‐protein interactions.
Analytical validation of a flow cytometric protocol for quantification of platelet microparticles in dogs
Authors: Cremer Signe E. , Krogh Anne K. H. , Hedström Matilda E. K. , Christiansen Liselotte B. , Tarnow Inge , Kristensen Annemarie T.
Published: March 2018

Background

Platelet microparticles (PMPs) are subcellular procoagulant vesicles released upon platelet activation. In people with clinical diseases, alterations in PMP concentrations have been extensively investigated, but few canine studies exist.

Objectives

This study aims to validate a canine flow cytometric protocol for PMP quantification and to assess the influence of calcium on PMP concentrations.

Methods

Microparticles (MP) were quantified in citrated whole blood (WB) and platelet‐poor plasma (PPP) using flow cytometry. Anti‐CD61 antibody and Annexin V (AnV) were used to detect platelets and phosphatidylserine, respectively. In 13 healthy dogs, CD61+/AnV− concentrations were analyzed with/without a calcium buffer. CD61+/AnV−, CD61+/AnV+, and CD61−/AnV+ MP quantification were validated in 10 healthy dogs. The coefficient of variation (CV) for duplicate (intra‐assay) and parallel (inter‐assay) analyses and detection limits (DLs) were calculated.

Results

CD61+/AnV− concentrations were higher in calcium buffer; 841,800 MP/μL (526,000‐1,666,200) vs without; 474,200 MP/μL (278,800‐997,500), P < .05. In WB, PMP were above DLs and demonstrated acceptable (<20%) intra‐assay and inter‐assay CVs in 9/10 dogs: 1.7% (0.5‐8.9) and 9.0% (0.9‐11.9), respectively, for CD61+/AnV− and 2.4% (0.2‐8.7) and 7.8% (0.0‐12.8), respectively, for CD61+/AnV+. Acceptable CVs were not seen for the CD61−/AnV+ MP. In PPP, quantifications were challenged by high inter‐assay CV, overlapping DLs and hemolysis and lipemia interfered with quantification in 5/10 dogs.

Conclusions

Calcium induced higher in vitro PMP concentrations, likely due to platelet activation. PMP concentrations were reliably quantified in WB, indicating the potential for clinical applications. PPP analyses were unreliable due to high inter‐CV and DL overlap, and not obtainable due to hemolysis and lipemia interference.
Multicenter in vitro thromboelastography and thromboelastometry standardization
Authors: Goggs Robert , Borrelli Antonio , Brainard Benjamin M. , Chan Daniel L. , de Laforcade Armelle , Goy‐Thollot Isabelle , Jandrey Karl E. , Kristensen Annemarie T. , Kutter Annette , Marschner Clara B. , Rannou Benoît , Sigrist Nadja , Wagg Catherine
Published: March 2018

Objective

To establish and compare the repeatability and reproducibility of activated thromboelastography (TEG) and thromboelastometry (ROTEM) assays.

Design

Multicenter in vitro test standardization.

Setting

Veterinary academic centers.

Animals

Test samples were obtained from normal, healthy dogs. Sixty identical 5 mL aliquots of canine platelet‐rich plasma collected by apheresis, frozen in 6% dimethyl sulfoxide, were tested initially. Sixty identical 6 mL aliquots of canine fresh frozen plasma with admixed cryoprecipitate were subsequently evaluated.

Interventions

None.

Measurements and Main Results

Frozen study samples, quality controls, reagents, and consumables were distributed to participating centers (7 TEG and 3 ROTEM). TEG centers analyzed study samples with kaolin and tissue factor activated assays; ROTEM centers ran proprietary ellagic acid activated and tissue factor activated assays. All machines underwent quality control prior to sample analysis. Within‐ and between‐center coefficients of variation (CVs) were calculated and compared using Mann–Whitney tests and calculation of intraclass correlation coefficients. Within and between centers, individual parameters for both TEG and ROTEM assays were comparable. Both within‐center and between‐center CVs varied markedly (0.7–120.5% and 1.4–116.5%, respectively) with assay type, instrument, and parameter. CVs for equivalent parameters were not significantly different between the 2 platforms. Intraclass correlation coefficients suggested moderate agreement between centers. In general, individual parameter CVs for platelet‐rich plasma samples were lower in TEG centers, while CVs for canine fresh frozen plasma with admixed cryoprecipitate samples were lower in ROTEM centers.

Conclusions

More variation within and between centers was identified than anticipated, but some parameters such as alpha angle were repeatable and reproducible. Sample types for future multicenter standardization efforts will require further optimization and may need to be adapted separately to each platform. Individual centers using viscoelastic tests for evaluation and management of clinical patients should take steps to minimize preanalytical and analytical sources of variation.
Arthroscopic removal of osteochondral fragments in the dorsal pouch of the proximal intertarsal joint in 29 horses
Authors: Espinosa‐Mur Pablo , Coté Nathalie , Desjardins Marc R.
Published: March 2018

Objective

To describe the radiographic and surgical findings of horses with osteochondral fragments (OCF) in the proximal intertarsal joint (PIJ) and to detail the technique for arthroscopic fragment retrieval and report outcomes.

Study design

Retrospective case series.

Animals

Twenty‐nine horses (32 tarsi) with OCF in the PIJ.

Methods

Medical records of horses with radiographic evidence of OCF in the PIJ were reviewed. Clinical features, number of fragments, location, arthroscopic appearance, and outcome were recorded. Technical modifications with visual aids specific to this arthroscopic technique are described.

Results

Twenty‐seven horses (93%) had radiographic evidence of osteochondritis dissecans lesions in the tarsocrural joint (TCJ). OCF were most commonly located distal to the medial trochlear ridge of the talus. In all cases, fragments were successfully retrieved with a technique based on exposing the fragments after resection of the proximal intertarsal joint capsule (PIJC). Fragments were visible from the TCJ prior resection of the PIJC in 4 of 32 tarsi. A third portal was created to access fragments located distal to the lateral trochlear ridge in 3 of 32 tarsi. Moderate intra‐articular bleeding occurred when the PIJC was resected in 3 of 32 tarsi. One horse had postoperative swelling that resolved with conservative medical management. All horses with long‐term follow‐up available (16/29) started training or returned to their athletic career.

Conclusion and clinical significance

The arthroscopic technique based on resection of PIJC was effective in retrieving OCF in the PIJ and was associated with minor complications. The clinical relevance of these fragments in the PIJ remains unknown.
Reviewer Acknowledgements
Authors: Smith Robert
Published: March 2018

Journal of Education and Training Studies (JETS) would like to acknowledge the following reviewers for their assistance with peer review of manuscripts for this issue. Many authors, regardless of whether JETS publishes their work, appreciate the helpful feedback provided by the reviewers. Their comments and suggestions were of great help to the authors in improving the quality of their papers. Each of the reviewers listed below returned at least one review for this issue.Reviewers for Volume 6, Number 4 Burcu Duman, Bartin University, TurkeyChosang Tendhar, Long Island University (LIU), USAEman ElBealy, Kiing Khalid University, Saudi ArabiaErkut Tutkun, Uludağ University, TurkeyFadime Seçgin, Gaziosmanpaşa University, TurkeyFatih Yazıcı, TurkeyGökhan Gencer, TurkeyHüseyin Eroğlu, Turkeyİbrahim Yaşar Kazu, Firat University, TurkeyIntakhab Khan, King Abdulaziz University, Saudi ArabiaIoannis Syrmpas, University of Thessaly, GreeceIşıl Tanriseven, Mersin University, TurkeyJohn Bosco Azigwe, Bolgatanga Polytechnic, GhanaKadir Yıldız, TurkeyLisa Marie Portugal, Grand Canyon University, USALorna T. Enerva, Polytechnic University of the Philippines, PhilippinesMaria Pavlis Korres, Hellenic Open University, GreeceMark Willems, University of Chichester, TurkeyMehmet Elban, TurkeyMehmet Inan, Marmara University, TurkeyMetin Kaya, TurkeyMurat Taş, TurkeyMurtaza Aykaç, Niğde Ömer Halis Demir University, TurkeyMustafa Gümüş, Bulent Ecevit University, TurkeyMuzaffer Selcuk, TurkeyNecdet Ekinci, TurkeyÖnder Dağlıoğlu, Gaziantep University, TurkeyPirkko Siklander, University of Lapland, FinlandRichard H. Martin, Mercer University, USARichard Penny, University of Washington Bothell, USASadia Batool, Preston University Islamabad, PakistanSelcuk Akpinar, TurkeySerdar Büyükipekçi, TurkeySermin Algul, TurkeySerpil Özdemir, Bartin University, TurkeySimona Savelli, Università degli Studi Guglielmo Marconi, ItalySisi Chen, American University of Health Sciences, USASüleyman Murat Yildiz, Muğla Sıtkı Koçman University, TurkeyTurhan Toros, TurkeyUğur Sönmezoğlu, Pamukkale University, TurkeyVedat Ayan, TurkeyVedat Cinar, TurkeyVeronica Rosa, University Rome, ItalyYerlan Seisenbekov, Kazakh National Pedagogical University, KazakhstanZeynep Dinç, Turkey                          Robert SmithEditorial AssistantOn behalf of,The Editorial Board of Journal of Education and Training StudiesRedfame Publishing9450 SW Gemini Dr. #99416Beaverton, OR 97008, USAURL: http://jets.redfame.com
Agreement Errors in Learner Corpora across CEFR: A Computer-Aided Error Analysis of Greek and Turkish EFL Learners Written Productions
Authors: Can Cem
Published: March 2018

This paper illustrates the use of learner corpus data (extracted from Cambridge Learner Corpus – CLC) to carry out an error analysis to investigate authentic learner errors and their respective frequencies in terms of types and tokens as well as contexts in which they regularly occur across four distinct proficiency levels, B1-B2; C1-C2, as defined by Common European Framework of Reference for Languages (henceforth CEFR) (Council of Europe, 2001). As a variety of learner corpora compiled by researchers become relatively accessible, it is possible to explore interlanguage errors and conduct error analysis (EA) on learner-generated texts. The necessity to cogitate over these authentic learner errors in designing foreign language learning programs and remedial teaching materials has been widely emphasized by many researchers (see e.g., Juozulynas, 1994; Mitton, 1996; Cowan, Choi, & Kim, 2003; Ndiaye & Vandeventer Faltin, 2003; Allerton et al., 2004). This study aims at conducting a corpus-based error analysis of agreement errors to reveal the related error categories between Greek and Turkish EFL learners, the distribution of agreement errors along the B1 - C2 proficiency range according to CEFR, and the distribution of agreement error types in respect of the L1 of the learners. The data analyzed in this study is extracted from the Cambridge Learner Corpus (CLC), the largest annotated test performance corpus which enables the investigation of the linguistic and rhetorical features of the learner performances in the above stated proficiency bands. The findings from this study reveal that, across B1-C2 proficiency levels and across different registers and genres, the most common agreement error categories by the frequency in which they occur are Verb Agreement (AGV), Noun Agreement (AGN), Anaphor Agreement (AGA), Determiner Agreement (AGD), Agreement Error (AG), and Quantifier Agreement (AGQ) errors. This study’s approach uses the techniques of computer corpus linguistics and follows the steps of the Error Analysis framework proposed by Corder (1971): identification, description, classification and explanation of errors.
Metaboreceptor activation in heart failure with reduced ejection fraction: Linking cardiac and peripheral vascular haemodynamics
Authors: Barrett‐O'Keefe Zachary , Lee Joshua F. , Berbert Amanda , Witman Melissa A. H. , Nativi‐Nicolau Jose , Stehlik Josef , Richardson Russell S. , Wray D. Walter
Published: March 2018

New Findings

What is the central question of this research?

Do patients with heart failure with reduced ejection fraction (HFrEF) exhibit a greater dependence on cardiac or peripheral vascular haemodynamics across multiple levels of muscle metaboreflex activation provoked by postexercise circulatory occlusion?

What is the main finding and its importance?

The metaboreflex‐induced pressor response in HFrEF patients is governed almost entirely by the peripheral circulation, which places a substantial haemodynamic load on the failing heart. This maladaptive response exacerbates the disease‐related impairment of systolic function that is a hallmark feature of HFrEF and may therefore contribute to exercise intolerance in this patient group.

We sought to evaluate the muscle metaboreflex in heart failure with reduced ejection fraction (HFrEF) patients, with an emphasis on the interaction between cardiac and peripheral vascular haemodynamics across multiple levels of metaboreceptor activation. In 23 HFrEF patients (63 ± 2 years of age) and 15 healthy control subjects (64 ± 3 years of age), we examined changes in mean arterial pressure, cardiac output, systemic vascular conductance, effective arterial elastance, stroke work and forearm deoxyhaemoglobin concentration during metaboreceptor activation elicited by postexercise circulatory occlusion (PECO) after three levels of static‐intermittent handgrip exercise (15, 30 and 45% maximal voluntary contraction). Across workloads, the metaboreflex‐induced increase in deoxyhaemoglobin and mean arterial pressure were similar between groups. However, in control subjects, the pressor response was driven by changes (Δ) in cardiac output  (Δ495 ± 155, Δ564 ± 156 and Δ666 ± 217 ml min−1), whereas this change was accomplished by intensity‐dependent reductions in systemic vascular conductance in patients with HFrEF (Δ−4.9 ± 1.5, Δ−9.1 ± 1.9 and Δ−12.7 ± 1.8 ml min mmHg−1). This differential response contributed to the exaggerated increases in effective arterial elastance in HFrEF patients compared with control subjects, coupled with a blunted response in stroke work in the HFrEF patients. Together, these findings indicate a preserved role of the metaboreflex‐induced pressor response in HFrEF but suggest that this response is governed by changes in the peripheral circulation. The net effect of this response appears to be maladaptive, as it places a substantial haemodynamic load on the left ventricle that may exacerbate left ventricular systolic dysfunction and contribute to exercise intolerance in this patient population.
Initiation and slow propagation of epileptiform activity from ventral to dorsal medial entorhinal cortex is constrained by an inhibitory gradient
Authors: Ridler Thomas , Matthews Peter , Phillips Keith G. , Randall Andrew D. , Brown Jonathan T.
Published: March 2018

Key points

The medial entorhinal cortex (mEC) has an important role in initiation and propagation of seizure activity. Several anatomical relationships exist in neurophysiological properties of mEC neurons; however, in the context of hyperexcitability, previous studies often considered it as a homogeneous structure.

Using multi‐site extracellular recording techniques, ictal‐like activity was observed along the dorso‐ventral axis of the mEC in vitro in response to various ictogenic stimuli. This originated predominantly from ventral areas, spreading to dorsal mEC with a surprisingly slow velocity.

Modulation of inhibitory tone was capable of changing the slope of ictal initiation, suggesting seizure propagation behaviours are highly dependent on levels of GABAergic function in this region.

A distinct disinhibition model also showed, in the absence of inhibition, a prevalence for interictal‐like initiation in ventral mEC, reflecting the intrinsic differences in mEC neurons.

These findings suggest the ventral mEC is more prone to hyperexcitable discharge than the dorsal mEC, which may be relevant under pathological conditions.

The medial entorhinal cortex (mEC) has an important role in the generation and propagation of seizure activity. The organization of the mEC is such that a number of dorso‐ventral relationships exist in neurophysiological properties of neurons. These range from intrinsic and synaptic properties to density of inhibitory connectivity. We examined the influence of these gradients on generation and propagation of epileptiform activity in the mEC. Using a 16‐shank silicon probe array to record along the dorso‐ventral axis of the mEC in vitro, we found 4‐aminopyridine application produces ictal‐like activity originating predominantly in ventral areas. This activity spreads to dorsal mEC at a surprisingly slow velocity (138 μm s−1), while cross‐site interictal‐like activity appeared relatively synchronous. We propose that ictal propagation is constrained by differential levels of GABAergic control since increasing (diazepam) or decreasing (Ro19‐4603) GABAA receptor activation, respectively, reduced or increased the slope of ictal initiation. The observation that ictal activity is predominately generated in ventral mEC was replicated using a separate 0‐Mg2+ model of epileptiform activity in vitro. By using a distinct disinhibition model (co‐application of kainate and picrotoxin) we show that additional physiological features (for example intrinsic properties of mEC neurons) still produce a prevalence for interictal‐like initiation in ventral mEC. These findings suggest that the ventral mEC is more likely to initiate hyperexcitable discharges than the dorsal mEC, and that seizure propagation is highly dependent on levels of GABAergic expression across the mEC.
Inhibition of Na+/K+‐ATPase and KIR channels abolishes hypoxic hyperaemia in resting but not contracting skeletal muscle of humans
Authors: Racine Matthew L. , Crecelius Anne R. , Luckasen Gary J. , Larson Dennis G. , Dinenno Frank A.
Published: March 2018

Key points

Increasing blood flow (hyperaemia) to exercising muscle helps match oxygen delivery and metabolic demand. During exercise in hypoxia, there is a compensatory increase in muscle hyperaemia that maintains oxygen delivery and tissue oxygen consumption.

Nitric oxide (NO) and prostaglandins (PGs) contribute to around half of the augmented hyperaemia during hypoxic exercise, although the contributors to the remaining response are unknown.

In the present study, inhibiting NO, PGs, Na+/K+‐ATPase and inwardly rectifying potassium (KIR) channels did not blunt augmented hyperaemia during hypoxic exercise beyond previous observations with NO/PG block alone. Furthermore, although inhibition of only Na+/K+‐ATPase and KIR channels abolished hyperaemia during hypoxia at rest, it had no effect on augmented hyperaemia during hypoxic exercise.

This is the first study in humans to demonstrate that Na+/K+‐ATPase and KIR channel activation is required for augmented muscle hyperaemia during hypoxia at rest but not during hypoxic exercise, thus providing new insight into vascular control.

Exercise hyperaemia in hypoxia is augmented relative to the same exercise intensity in normoxia. During moderate‐intensity handgrip exercise, endothelium‐derived nitric oxide (NO) and vasodilating prostaglandins (PGs) contribute to ∼50% of the augmented forearm blood flow (FBF) response to hypoxic exercise (HypEx), although the mechanism(s) underlying the remaining response are unclear. We hypothesized that combined inhibition of NO, PGs, Na+/K+‐ATPase and inwardly rectifying potassium (KIR) channels would abolish the augmented hyperaemic response in HypEx. In healthy young adults, FBF responses were measured (Doppler ultrasound) and forearm vascular conductance was calculated during 5 min of rhythmic handgrip exercise at 20% maximum voluntary contraction under regional sympathoadrenal inhibition in normoxia and isocapnic HypEx (O2 saturation ∼80%). Compared to control, combined inhibition of NO, PGs, Na+/K+‐ATPase and KIR channels (l‐NMMA + ketorolac + ouabain + BaCl2; Protocol 1; n = 10) blunted the compensatory increase in FBF during HypEx by ∼50% (29 ± 6 mL min−1 vs. 62 ± 8 mL min−1, respectively, P < 0.05). By contrast, ouabain + BaCl2 alone (Protocol 2; n = 10) did not affect this augmented hyperaemic response (50 ± 11 mL min−1 vs. 60 ± 13 mL min−1, respectively, P > 0.05). However, the blocked condition in both protocols abolished the hyperaemic response to hypoxia at rest (P < 0.05). We conclude that activation of Na+/K+‐ATPase and KIR channels is involved in the hyperaemic response to hypoxia at rest, although it does not contribute to the augmented exercise hyperaemia during hypoxia in humans.
Moderate and severe hypoxia elicit divergent effects on cardiovascular function and physiological rhythms
Authors: Allwood Melissa A. , Edgett Brittany A. , Eadie Ashley L. , Huber Jason S. , Romanova Nadya , Millar Philip J. , Brunt Keith R. , Simpson Jeremy A.
Published: March 2018

Key points

In the present study, we provide evidence for divergent physiological responses to moderate compared to severe hypoxia, addressing an important knowledge gap related to severity, duration and after‐effects of hypoxia encountered in cardiopulmonary situations.

The physiological responses to moderate and severe hypoxia were not proportional, linear or concurrent with the time‐of‐day.

Hypoxia elicited severity‐dependent physiological responses that either persisted or fluctuated throughout normoxic recovery.

The physiological basis for these distinct cardiovascular responses implicates a shift in the sympathovagal set point and probably not molecular changes at the artery resulting from hypoxic stress.

Hypoxia is both a consequence and cause of many acute and chronic diseases. Severe hypoxia causes hypertension with cardiovascular sequelae; however, the rare studies using moderate severities of hypoxia indicate that it can be beneficial, suggesting that hypoxia may not always be detrimental. Comparisons between studies are difficult because of the varied classifications of hypoxic severities, methods of delivery and use of anaesthetics. Thus, to investigate the long‐term effects of moderate hypoxia on cardiovascular health, radiotelemetry was used to obtain in vivo physiological measurements in unanaesthetized mice during 24 h of either moderate or severe hypoxia, followed by 72 h of normoxic recovery. Systolic blood pressure was decreased during recovery following moderate hypoxia but increased following severe hypoxia. Moderate and severe hypoxia increased haeme oxygenase‐1 expression during recovery, suggesting parity in hypoxic stress at the level of the artery. Severe but not moderate hypoxia increased the low/high frequency ratio of heart rate variability 72 h post‐hypoxia, indicating a shift in sympathovagal balance. Moderate hypoxia dampened the amplitude of circadian rhythm, whereas severe disrupted rhythm during the entire insult, with perturbations persisting throughout normoxic recovery. Thus, hypoxic severity differentially regulates circadian blood pressure.
Stable Isotope Probing for Microbial Iron Reduction in Chocolate Pots Hot Spring, Yellowstone National Park
Authors: Fortney Nathaniel W. , He Shaomei , Kulkarni Ajinkya , Friedrich Michael W. , Holz Charlotte , Boyd Eric S. , Roden Eric E.
Published: March 2018

Chocolate Pots hot springs (CP) is a circumneutral-pH Fe-rich geothermal feature located in Yellowstone National Park. Previous Fe(III)-reducing enrichment culture studies with CP sediments identified close relatives of known dissimilatory Fe(III)-reducing bacterial (FeRB) taxa, including
Geobacter
and
Melioribacter
. However, the abundances and activities of such organisms in the native microbial community are unknown. Here, we used stable isotope probing experiments combined with 16S rRNA gene amplicon and shotgun metagenomic sequencing to gain an understanding of the
in situ
Fe(III)-reducing microbial community at CP. Fe-Si oxide precipitates collected near the hot spring vent were incubated with unlabeled and
13
C-labeled acetate to target active FeRB. We searched reconstructed genomes for homologs of genes involved in known extracellular electron transfer (EET) systems to identify the taxa involved in Fe redox transformations. Known FeRB taxa containing putative EET systems (
Geobacter
,
Ignavibacteria
) increased in abundance under acetate-amended conditions, whereas genomes related to
Ignavibacterium
and
Thermodesulfovibrio
that contained putative EET systems were recovered from incubations without electron donor. Our results suggest that FeRB play an active role in Fe redox cycling within Fe-Si oxide-rich deposits located at the hot spring vent.

IMPORTANCE
The identification of past near-surface hydrothermal environments on Mars emphasizes the importance of using modern Earth environments, such as CP, to gain insight into potential Fe-based microbial life on other rocky worlds, as well as ancient Fe-rich Earth ecosystems. By combining stable carbon isotope probing techniques and DNA sequencing technology, we gained insight into the pathways of microbial Fe redox cycling at CP. The results suggest that microbial Fe(III) oxide reduction is prominent
in situ
, with important implications for the generation of geochemical and stable Fe isotopic signatures of microbial Fe redox metabolism within Fe-rich circumneutral-pH thermal spring environments on Earth and Mars.
Comparison of an
In Vitro
Diagnostic Next-Generation Sequencing Assay with Sanger Sequencing for HIV-1 Genotypic Resistance Testing
Authors: Tzou Philip L. , Ariyaratne Pramila , Varghese Vici , Lee Charlie , Rakhmanaliev Elian , Villy Carolin , Yee Meiqi , Tan Kevin , Michel Gerd , Pinsky Benjamin A. , Shafer Robert W.
Published: March 2018

The ability of next-generation sequencing (NGS) technologies to detect low frequency HIV-1 drug resistance mutations (DRMs) not detected by dideoxynucleotide Sanger sequencing has potential advantages for improved patient outcomes. We compared the performance of an
in vitro
diagnostic (IVD) NGS assay, the Sentosa SQ HIV genotyping assay for HIV-1 genotypic resistance testing, with Sanger sequencing on 138 protease/reverse transcriptase (RT) and 39 integrase sequences. The NGS assay used a 5% threshold for reporting low-frequency variants. The level of complete plus partial nucleotide sequence concordance between Sanger sequencing and NGS was 99.9%. Among the 138 protease/RT sequences, a mean of 6.4 DRMs was identified by both Sanger and NGS, a mean of 0.5 DRM was detected by NGS alone, and a mean of 0.1 DRM was detected by Sanger sequencing alone. Among the 39 integrase sequences, a mean of 1.6 DRMs was detected by both Sanger sequencing and NGS and a mean of 0.15 DRM was detected by NGS alone. Compared with Sanger sequencing, NGS estimated higher levels of resistance to one or more antiretroviral drugs for 18.2% of protease/RT sequences and 5.1% of integrase sequences. There was little evidence for technical artifacts in the NGS sequences, but the G-to-A hypermutation was detected in three samples. In conclusion, the IVD NGS assay evaluated in this study was highly concordant with Sanger sequencing. At the 5% threshold for reporting minority variants, NGS appeared to attain a modestly increased sensitivity for detecting low-frequency DRMs without compromising sequence accuracy.
Evaluation of choroidal lesions with swept-source optical coherence tomography
Authors: Ung Cindy , Laíns Inês , Silverman Rebecca F , Woods Russell , Lane Anne Marie , Papakostas Thanos D , Husain Deeba , Miller Joan W , Gragoudas Evangelos S , Kim Ivana K , Miller John B
Published: March 2018

Aims

The aim of our study was to image choroidal lesions with swept-source optical coherence tomography (SS-OCT) and to identify the morphological characteristics associated with optimal visualisation.

Methods

This was a prospective, cross-sectional study. Patients with choroidal melanocytic lesions <3 mm in thickness on B-scan ultrasonography were recruited. All participants underwent SS-OCT. On SS-OCT we evaluated qualitative (eg, lesion outline, detection of scleral-choroidal interface and quality of the image) and quantitative (measurement of maximum lesion thickness and the largest basal diameter) parameters. Probability of optimal image quality was examined using ordered logistic regression models. The main outcome measure was quality of the choroidal lesion images on SS-OCT, defined as: optimal, suboptimal or poor.

Results

We included 85 choroidal lesions of 82 patients. There were 24 choroidal lesions (29%) for which image quality was classified as optimal, 31 lesions (37%) as suboptimal and 30 lesions (36%) as poor. The factors associated with optimal image quality were distance closer to the fovea (OR 0.76, p<0.001), posterior pole location (OR 3.87, p=0.05), lower ultrasonography thickness (OR 0.44, p=0.04), lighter lesion pigmentation (OR 0.12, p=0.003) and smaller lesion diameter (OR 0.73, p<0.001). In the multivariable analysis, closer distance to the fovea (OR 0.81, p=0.005), lighter lesion pigmentation (OR 0.11, p=0.01) and smaller lesion diameter (OR 0.76, p=0.006) remained statistically significant.

Conclusion

SS-OCT is useful in imaging most choroidal melanocytic lesions. Image quality is best when the choroidal lesion is closer to the fovea, has a smaller diameter and a lighter choroidal pigmentation.
Assessing the health effects associated with occupational radiation exposure in Korean radiation workers: protocol for a prospective cohort study
Authors: Seo Songwon , Lim Wan Young , Lee Dal Nim , Kim Jung Un , Cha Eun Shil , Bang Ye Jin , Lee Won Jin , Park Sunhoo , Jin Young Woo
Published: March 2018

Introduction

The cancer risk of radiation exposure in the moderate-to-high dose range has been well established. However, the risk remains unclear at low-dose ranges with protracted low-dose rate exposure, which is typical of occupational exposure. Several epidemiological studies of Korean radiation workers have been conducted, but the data were analysed retrospectively in most cases. Moreover, groups with relatively high exposure, such as industrial radiographers, have been neglected. Therefore, we have launched a prospective cohort study of all Korean radiation workers to assess the health effects associated with occupational radiation exposure.

Methods and analysis

Approximately 42 000 Korean radiation workers registered with the Nuclear Safety and Security Commission from 2016 to 2017 are the initial target population of this study. Cohort participants are to be enrolled through a nationwide self-administered questionnaire survey between 24 May 2016 and 30 June 2017. As of 31 March 2017, 22 982 workers are enrolled in the study corresponding to a response rate of 75%. This enrolment will be continued at 5-year intervals to update information on existing study participants and recruit newly hired workers. Survey data will be linked with the national dose registry, the national cancer registry, the national vital statistics registry and national health insurance data via personal identification numbers. Age-specific and sex-specific standardised incidence and mortality ratios will be calculated for overall comparisons of cancer risk. For dose–response assessment, excess relative risk (per Gy) and excess absolute risk (per Gy) will be estimated with adjustments for birth year and potential confounders, such as lifestyle factors and socioeconomic status.

Ethics and dissemination

This study has received ethical approval from the institutional review board of the Korea Institute of Radiological and Medical Sciences (IRB No. K-1603-002-034). All participants provided written informed consent prior to enrolment. The findings of the study will be disseminated through scientific peer-reviewed journals and be provided to the public, including radiation workers, via the study website (http://www.rhs.kr/) and onsite radiation safety education.