bluuebunny/crossref_metadata_2025 huggingface dataset:
How Much Cardiopulmonary Resuscitation Does a Pediatric Emergency Provider Perform in 1 Year? A Video-Based Analysis
Authors: Donoghue Aaron , Abbadessa Mary Kate , Hsieh Ting-Chang , Frankenberger Warren , Myers Sage
Published: September 2018

Objectives

We aimed to quantify time performing chest compressions (CCs) per year of individual providers in a pediatric ED and to project a rate of opportunity for CC based on median clinical hours per provider category.

Methods

This was an observational study of video-recorded resuscitations in a pediatric ED over 1 year. Events where CCs were performed for more than 2 minutes were included. Identification of providers and duration of CCs per provider were determined by video review. Time of CCs was totaled per provider over the study period. Data were expressed as median and interquartile range (IQR). Rate of opportunity for providing CC to a child was calculated by dividing the median clinical hours per year per provider type by the number of CC events per year.

Results

Twenty-three CC events totaling 340 minutes of CCs were analyzed. Chest compressions were performed by 6 (13%) of 45 attending physicians, 3 (25%) of 12 fellows, 32 (22%) of 143 nurses, and 19 (59%) of 32 technicians. The median amount of time performing CC was 182 seconds (IQR, 91–396 seconds); by provider category, median amount of time was as follows: attending physicians, 83 seconds (IQR, 64–103 seconds); fellows, 45 seconds (IQR, 6–83 seconds); nurses, 128 seconds (IQR, 93–271 seconds); and technicians, 534 seconds (IQR, 217–793 seconds). The projected hours needed for an opportunity to perform CCs was 730 hours (91 shifts) for attending physicians, 243 hours (30 shifts) for fellows, and 1460 hours (121 shifts) for nurses and technicians.

Conclusions

Performing CCs on children in the ED is a rare event, with a median of 3 minutes per provider per year. Future studies should determine training methods to optimize readiness for these rare occurrences.
Classic and “Dissecting” Gonadoblastoma in a Phenotypic Girl With a 46, XX Peripheral Karyotype and No Evidence of a Disorder of Sex Development
Authors: Roth Lawrence M. , Davis Mary M. , Czernobilsky Bernard
Published: September 2018

Herein, we report a case of a 9-yr-old girl who had a 46, XX peripheral karyotype and apparent developmentally normal ovaries. She presented with abdominal pain and a right adnexal mass. No clinical or pathologic evidence of gonadal dysgenesis or undifferentiated gonadal tissue was detected. She underwent right salpingo-oophorectomy with rupture of the tumor at the time of operation due to recent adnexal torsion. The original pathologic diagnosis was gonadoblastoma and mixed germ cell tumor. Most significantly in our study, we identified a rare and novel pathway for the development of malignant mixed germ cell tumor from gonadoblastoma in the absence of identifiable dysgerminoma. The histologically identifiable steps of progression in our case were as follows: (1) residual islands of classic gonadoblastoma, (2) overgrowth by “dissecting” gonadoblastoma composed of transformed germ cells with clear cytoplasm and sex cord elements surrounded by a basement membrane, (3) stromal infiltration by dedifferentiated germ cells with loss of basement membrane, (4) formation of malignant mixed germ cell tumor. The dedifferentiated areas were composed of anaplastic germ cells with amphophilic cytoplasm that gradually replaced the sex cord elements by clonal expansion. Both the original transformed and the anaplastic germ cell components strongly expressed OCT4. We believe that the mixed germ cell tumor arose from the dedifferentiated germ cell component through neoplastic progression. This premise suggests that the germ cell component of “dissecting” gonadoblastoma rarely undergoes anaplastic change in the absence of transition to germinoma and can be the direct precursor of mixed germ cell tumor.
Safety in Hand Surgery: Eliminating Wrong-Site Surgery
Authors: Brown Ronald D. , Hammert Warren C.
Published: September 2018

Learning Objectives:

After studying this article, the participant should be able to: 1. Understand the definition of wrong-site surgery and what it may encompass. 2. State the causes of wrong-site hand surgery. 3. Give examples of initiatives used to prevent wrong-site surgery. 4. Describe a process to minimize the risk of performing wrong-site surgery.

Wrong-site surgery remains a problem in our ever-evolving culture of surgical safety, and hand surgeons are at particularly high risk. Broadly speaking, wrong-site surgery is a procedure performed at an incorrect anatomical site. In hand surgery, this includes errors in laterality, wrong digit(s), wrong procedure(s), or even a failure to complete all indicated procedures. This article examines the scope of this safety issue, the current challenges to preventing wrong-site surgery, and the authors’ proposed solutions to eliminating wrong-site surgery and establishing a culture of safety in hand surgery.
PET/CT Imaging for Solitary Primary Bone Lymphoma of Thoracic Vertebra
Authors: Shen Guohua , Su Minggang , Liu Bin , Kuang Anren
Published: September 2018

Primary bone lymphoma without classic nodal lesions or advanced disease may be mistaken for other osseous diseases, especially when involving a single bone site. In this patient, a series of imaging modalities including MRI, bone scan, and 18F-FDG PET/CT revealed only 1 solitary osseous lytic lesion with abnormal uptake in the third thoracic vertebra, suggesting a primary skeletal malignancy. The subsequent histopathologic examination confirmed the diagnosis of diffuse large B-cell lymphoma. After chemotherapy, he achieved an excellent clinical and metabolic response.
Uptake of Prostate-Specific Membrane Antigen–Targeted 18F-DCFPyL in Cerebral Radionecrosis
Authors: Salas Fragomeni Roberto A. , Pienta Kenneth J. , Pomper Martin G. , Gorin Michael A. , Rowe Steven P.
Published: September 2018

Recent PET imaging of glioblastoma multiforme and other high-grade gliomas using prostate-specific membrane antigen (PSMA)–targeted small-molecule radiotracers suggests a role for these agents in diagnostic imaging of recurrent/residual tumor and that PSMA-targeted endoradiotherapies may provide a new approach to therapy for patients with these difficult-to-treat tumors. We present a case of cerebral radionecrosis demonstrating PSMA-targeted radiotracer uptake. Our findings may represent a potential pitfall and limitation to the diagnostic application of PSMA-targeted agents for high-grade gliomas.
Pedicled Flaps Versus Free Flaps for Back Reconstruction
Authors: Komagoe Sho , Watanabe Toshiyuki , Komatsu Seiji , Kimata Yoshihiro
Published: September 2018

Background

Back reconstructions using a flap are relatively rare, and clinical reports on such reconstructions are few. We analyzed whether a pedicled flap or free flap was best for treating back defects and established a simplified algorithm for flap selection.

Methods

We retrospectively analyzed the cases of 22 patients who underwent flap reconstructions for the back between July 2000 and August 2016. We extracted data on the operative time, defect size, patients' height and body weight, and reoperation, and each defect size was calculated as a percentage in relation to the body surface area (BSA). We compared these values between both flap types using univariate analysis. In addition, reconstructions using pedicled flaps were classified as single pedicled flap and combination pedicled flap reconstructions. The reasons for reoperation were also reviewed.

Result

Seventeen patients underwent reconstructions using pedicled flaps, and 5 patients underwent reconstructions using free flaps. The operative time and the percentage of defect size in relation to the BSA were significantly lower when using pedicled flaps than when using free flaps (P = 0.002, P = 0.046, respectively). There was no significant difference in terms of the rate of reoperation (P = 0.16) between the 2 types of reconstructions. The operative time was also significantly shorter when using combination pedicled flaps than when using free flaps. However, there was no significant difference in terms of the percentage of defect size in relation to the BSA between combination pedicled flaps and free flaps. Reoperation was necessary because of flap necrosis in pedicled flaps and skin graft necrosis in free flaps.

Conclusions

Our results demonstrated that pedicled flaps should be the first choice for back reconstruction, independent of the defect size, reoperation rate, and reason for reoperation. This is because the operation time required is significantly lower, which benefits patients and surgeons. Free flaps can be used when pedicled flaps cannot be used efficiently.
Skin-Reducing Mastectomy and Direct-to-Implant Breast Reconstruction With Submuscular-Dermal-Mesh Pocket
Authors: Bonomi Stefano , Sala Laura , Gennaro Massimiliano , Ricci Cristian , Cortinovis Umberto
Published: September 2018

Background

Despite skin-sparing mastectomy techniques have significantly improved reconstructive options and aesthetic outcomes, patients with large and ptotic breasts remain a challenging group to treat satisfactorily. The Wise-pattern skin-reducing mastectomy (SRM) has been designed for this kind of patients but is not without morbidity. To improve safety, the authors reviewed their experience with a modified SRM and immediate 1-stage implant-based breast reconstruction, using a synthetic absorbable mesh combined with a dermal flap.

Methods

A retrospective review was undertaken to identify women with medium to large ptotic breast and medium minimally ptotic breast who had undergone SRM and direct-to-implant breast reconstruction using definitive anatomical gel implant, de-epithelialized dermal flap, and absorbable synthetic mesh, between October 2014 and December 2016. Patient demographics were queried, and complication rates, aesthetic outcomes, and patients satisfaction were assessed.

Results

Sixty-two procedures of SRM were performed in 56 patients. Forty-five women received contralateral symmetrization. Twenty-one overall complications occurred in 16 patients. Statistical correlation between risk factors and complications onset was assessed. Body mass index resulted the most substantial risk factor (P = 0.0028) for developing complications, whereas preoperative chemotherapy (P = 0.0050) and comorbidities (P = 0.0117) played a decent role. Smoking attitude (P = 0.1122), age (P = 0.9990), and implant weight (P = 0.1583) did not result as significant risk factors. The reconstructive outcomes were good to excellent in 92.8%, with patient satisfaction ranking very to highly satisfied in 84%.

Conclusions

The authors' series suggests that SRM with direct-to-implant breast reconstruction can be easily performed when an appropriate SRM pattern is designed, providing complete implant coverage with submuscular-dermal-mesh pocket.
US FDA Breast Implant Postapproval Studies
Authors: Coroneos Christopher J. , Selber Jesse C. , Offodile Anaeze C. , Butler Charles E. , Clemens Mark W.
Published: September 2018

Objective:

To analyze the long-term safety and efficacy outcomes of patients with breast implants.

Summary Background Data:

Research is ongoing regarding the safety of silicone breast implants. Despite the number of patients with breast implants followed by United States Food and Drug Administration large postapproval studies (LPAS), this database has not been thoroughly analyzed or reported.

Methods:

This is a multicentered, cohort study. LPAS prospectively monitor long-term implant-related outcomes and systemic harms for silicone/saline implants from 2 manufacturers (Allergan and Mentor) placed for primary/revision augmentation/reconstruction. Systemic harms, self-harm, and reproductive outcomes are compared with normative data. Implant-related complications are analyzed by implant composition and operative indication in the short and long terms.

Results:

LPAS data includes 99,993 patients, 56% of implants were silicone for primary augmentation. Long-term magnetic resonance imaging surveillance is under 5%. Compared with normative data, silicone implants are associated with higher rates of Sjogren syndrome (Standardized incidence ratio [SIR]8.14), scleroderma (SIR 7.00), rheumatoid arthritis (SIR5.96), stillbirth (SIR4.50), and melanoma (SIR3.71). One case of BI-ALCL is reported. There is no association with suicide. In the short term, rupture is higher for saline (2.5% vs. 0.5%, P < 0.001), and capsular contracture higher for silicone (5.0% vs. 2.8%, P < 0.001). At 7 years, reoperation rate is 11.7% for primary augmentation, and 25% for primary/revision reconstruction. Capsular contracture (III/IV) occurs in 7.2% of primary augmentations, 12.7% primary reconstructions, and is the most common reason for reoperation among augmentations.

Conclusions:

This is the largest study of breast implant outcomes. Silicone implants are associated with an increased risk of certain rare harms; associations need to be further analyzed with patient-level data to provide conclusive evidence. Long-term safety and implant-related outcomes should inform patient and surgeon decision-making when selecting implants.
Patient-Initiated Telephone Calls in the Postoperative Period After Female Pelvic Reconstructive Surgery
Authors: Ramaseshan Aparna S. , LaSala Christine , O’Sullivan David M. , Steinberg Adam C.
Published: September 2018

Objective

The aim of this study was to evaluate reasons and factors associated with patient calls in the postoperative period after female pelvic medicine and reconstructive surgery.

Methods

A retrospective review using electronic medical records was performed on consecutive patients who underwent surgery within our academic female pelvic medicine and reconstructive surgery practice during a 6-month period. Calls after postoperative discharge until first scheduled postoperative visit were included. Reasons and number of calls were tabulated. Clinical and surgical factors were extracted. Continuous data were evaluated with a Student t test or analysis of variance; categorical data were evaluated with a χ2 test. P < 0.05 was considered significant.

Results

During the designated period, 302 patients underwent surgery, and 173 (57.3%) patients made 345 calls (mean ± SD, 2.0 ± 1.5 calls). Reasons were categorized under 6 distinct domains: bowel, pain, activity, medication regimen, urinary, and bleeding. The most frequent concern within each domain was constipation (11.6%), abdominal pain (6.4%), physical activity (8.7%), pain regimen (14.5%), urinary catheter related (13.3%), and vaginal bleeding (12.1%), respectively. A greater number of phone calls were recorded among patients discharged home with catheters (P = 0.015), and patients who underwent posterior colporrhaphy (P = 0.005) and retropubic urethropexy (P = 0.014). Patients discharged with home nursing (11, 6.4%) demonstrated a significantly higher number of phone calls (3.8 ± 2.5, P < 0.001). Evaluations were required for 37% of callers. Twelve patients were seen in the emergency department, of whom 3 (1.7%) were readmitted to the hospital.

Conclusions

Postoperative patient-initiated telephone calls after pelvic reconstructive surgery are common. Bowel-, urinary-, and medication-based phone calls account for the highest frequency and volume.
Evaluation of Urine Choline Levels in Women With and Without Overactive Bladder Syndrome
Authors: Sheyn David , Hijaz Adonis K. , Hazlett Fred E. , Dawodu Konyinsola , El-Nashar Sherif , Mangel Jeffrey M. , Petrikovets Andrey , Mahajan Sangeeta T.
Published: September 2018

Objective

The objective of this study was to determine whether levels of choline (Ch) differ in women with and without overactive bladder (OAB) symptoms.

Methods

New patients were evaluated using the overactive bladder symptom score; Medical, Epidemiologic, and Social Aspects of Aging (MESA) urgency incontinence questionnaire; and Impact Questionnaire 7 and provided a urine sample. Patients were stratified into asymptomatic controls, scoring 0 on overactive bladder symptom score and the MESA questionnaire, and patients with OAB and urgency incontinence (OAB-wet). Patients with conditions predisposing to OAB or had a history of OAB treatment were excluded. Choline detection was accomplished using a commercially available kit. Wilcoxon rank sum test and Fisher exact test were used to express differences between groups. Spearman ρ correlation was used to determine the relationship between Ch and questionnaire scores. Logistic regression was used to identify significant variables associated with OAB.

Results

Sixty-three women were included in the final analysis. Patients with OAB-wet were older (P = 0.001), more likely to be obese (P = 0.04), had greater apical descent (P = 0.02), were more likely to be postmenopausal (P = 0.01), and were more likely to have stress incontinence (P = 0.005). Choline was 34.8% lower in OAB compared with the controls (P = 0.014). Lower Ch levels were associated with higher MESA (Spearman ρ = −0.311, P = 0.03). After logistic regression, lower Ch (adjusted odds ratio [aOR], 0.97; 95% confidence interval [CI], 0.96–0.98), age (aOR, 1.12; 95% CI, 1.08–1.18), and body mass index (aOR, 1.09; 95% CI, 1.01–1.18) were significantly associated with OAB-wet.

Conclusions

Choline levels are significantly decreased in women complaining of OAB with urgency incontinence, and lower levels are associated with higher MESA scores.
Health-related quality of life in children after burn injuries: A systematic review
Authors: Spronk Inge , Legemate Catherine M. , Polinder Suzanne , van Baar Margriet E.
Published: September 2018

BACKGROUND

Through improved survival of burns, more children have to deal with consequences of burns. Health-related quality of life (HRQL) measurement is important to qualify the perceived burden of burns in children. No systematic study of this outcome in children exists. Therefore, our objective was to review study designs, instruments, methodological quality, outcomes, and predictors of HRQL in children after burns.

METHODS

A systematic literature search was conducted in CINAHL, Embase, Google Scholar, Medline, The Cochrane library, and Web of science (PROSPERO ID, CRD42016048065). Studies examining HRQL in pediatric burn patients were included. The risk of bias was assessed using the Quality in Prognostic Studies (QUIPS) tool.

RESULTS

Twenty-seven studies using 12 HRQL instruments were included. The Burns Outcome Questionnaire aged 0 to 4 and 5 to 18 years were most often applied. All longitudinal studies showed improvement of HRQL over time. However, problems were reported on the longer term on the domains “(parental) concern” and “appearance.” Parental proxy scores were in general comparable to children's self-ratings. Severity of burns, facial burns, hand burns, comorbidity, and short time since burn predicted an impaired HRQL. The risk of bias of the studies was, in general, moderate.

CONCLUSION

Health-related quality of life in children after burns increases over time. Domains and patient groups that require special attention are identified. However, due to lack of comparability of studies, the available information could not be used optimally. To further improve our understanding of HRQL, consensus on design, data-analysis, and data presentation are needed.

LEVEL OF EVIDENCE

Systematic review, level III.
Neurophysiological Evidence of Motor Network Reorganization in Myotonic Dystrophy Type 1: A Pilot Magnetoencephalographic Study
Authors: Formaggio Emanuela , Del Felice Alessandra , Turco Cristina , Cudia Paola , Baba Alfonc , Bevilacqua Francesca , Masiero Stefano , Piccione Francesco
Published: September 2018

Purpose:

Myotonic dystrophy type 1 is the most common muscular dystrophy in adults. Although brain involvement is well recognized, the relationship between cortical motor control and voluntary movement has not been sufficiently explored. This study aims at assessing magnetoencephalographic (MEG) rhythms at oscillatory and connectivity levels to map central motor control.

Methods:

Magnetoencephalographic data were acquired from healthy subjects and five myotonic dystrophy type 1 subjects during resting state and foot movement. Resting state EEG band power, event-related desynchronization/synchronization, functional connectivity, and network features (node strength and betweenness centrality) were estimated. A statistical comparison of these indexes between the two groups was run; a linear correlation between event-related desynchronization and motor performance was obtained.

Results:

Myotonic dystrophy type 1 subjects showed higher theta power over central motor regions and lower beta power over frontal areas, with a decrease of beta node strength over the dominant hemisphere and an increase of betweenness centrality over the vertex. Foot movement in the most impaired myotonic dystrophy type 1 subjects was inefficient in evoking event-related desynchronization. In less severely impaired participants, dominant foot movement was related to a bilateral sensorimotor event-related desynchronization.

Conclusions:

Results provide proof of a central dysfunction of movement. Identification of neurophysiological motor patterns in myotonic dystrophy type 1 could provide a guide for tailored therapy.
Fast and sensitive protein sequence homology searches using hierarchical cluster BLAST
Authors: Nasko Daniel J. , Wommack K. Eric , Ferrell Barbra D. , Polson Shawn W.
Published: September 2018

The throughput of DNA sequencing continues to increase, allowing researchers to analyze genomes of interest at greater depths. An unintended consequence of this data deluge is the increased cost of analyzing these datasets. As a result, genome and metagenome annotation pipelines are left with a few options: (i) search against smaller reference databases, (ii) use faster, but less sensitive, algorithms to assess sequence similarities, or (iii) invest in computing hardware specifically designed to improve BLAST searches such as GPGPU systems and/or large CPU-rich clusters.

We present a pipeline that improves the speed of amino acid sequence homology searches with a minimal decrease in sensitivity and specificity by searching against hierarchical clusters. Briefly, the pipeline requires two homology searches: the first search is against a clustered version of the database and the second is against sequences belonging to clusters with a hit from the first search. We tested this method using two assembled viral metagenomes and three databases (Swiss-Prot, Metagenomes Online, and UniRef100). Hierarchical cluster homology searching proved to be 12-times faster than BLASTp and produced alignments that were nearly identical to BLASTp (precision=0.99; recall=0.97). This approach is ideal when searching large collections of sequences against large databases.
Spatial ecology of Paraguay’s last remaining Atlantic forest jaguars (Panthera onca): implications for their long-term survival
Authors: McBride Roy T , Thompson Jeffrey J
Published: September 2018

Using GPS telemetry we quantified space use and movements of jaguar (Panthera onca) in remnant populations in the Paraguayan Atlantic forest within a comparative context with populations in the Argentine and Brazilian Atlantic forest. Mean estimated home range size was 160 km2; estimated to be nearly equal to jaguars in the Morro do Diabo State Park in Brazil but jaguars in other populations in Argentina and Brazil had a 73% (Iguazú/Iguaçu national park complex) and 96% (Ivinhema State Park) probability of having larger home ranges. We found no relationship between home range size or movements and human population or the Human Footprint Index, while 75% of locations from all individuals were in protected areas. Our data and analysis highlight the dependence of Atlantic forest jaguars on protected areas, an avoidance of the landscape matrix and an extreme isolation of the remaining Paraguayan Atlantic forest jaguars.
Setting the Occasion for Incentive Motivation: Implications for Addiction
Authors: Fraser Kurt M. , Janak Patricia H.
Published: September 2018

The context in which reward-paired cues are encountered sets the occasion for appropriate reward-seeking but may also spur inappropriate behaviors such as the renewal of drug-seeking. The psychological processes underlying occasion setting remain unclear as contexts are diffuse and difficult to isolate from other stimuli. To overcome this, we modeled a context as a phasic and discrete event – an occasion setter – which allowed for control over its presentation and influence on cue-driven reward-seeking. This allowed us to directly assess how occasion setters, like contexts, regulate the predictive and motivational significance of Pavlovian cues. Male rats (n=50) were trained in a Pavlovian paradigm where the presentation of an ambiguous conditioned stimulus was reinforced only if preceded by an occasion setting cue. We assessed the motivational value of the occasion setter and conditioned stimulus alone or in combination using conditioned reinforcement. Rats showed enhanced conditioned approach to the reward port during the reward-adjacent conditioned stimulus when it was preceded by the occasion setter. When allowed the opportunity, rats responded more to obtain presentations of the conditioned stimulus in combination with the occasion setter than the conditioned stimulus alone. Critically, rats also worked to obtain presentations of the occasion setter alone more than the conditioned stimulus, and this was resistant to manipulations of the value of the occasion setter. We conclude that occasion setting can act via incentive motivational mechanisms and that, apart from resolving predictive information about ambiguous reward-paired cues, occasion setters themselves generate states of appetitive motivation that can facilitate reward-seeking.
The gene repressor complex NuRD interacts with the histone variant H3.3 at promoters of active genes
Authors: Kraushaar Daniel C. , Chen Zuozhou , Tang Qingsong , Cui Kairong , Zhang Junfang , Zhao Keji
Published: September 2018

The histone variant H3.3 is deposited across active genes, regulatory regions, and telomeres. It remains unclear how H3.3 interacts with chromatin modifying enzymes and thereby modulates gene activity. In this study, we performed a co-immunoprecipitation-mass spectrometry analysis of proteins associated with H3.3-containing nucleosomes and identified the nucleosome remodeling and deacetylase complex (NuRD) as a major H3.3-interactor. We show that the H3.3-NuRD interaction is dependent on the H3.3 lysine 4 residue and that NuRD binding occurs when lysine 4 is in its unmodified state. The majority of NuRD binding colocalizes with H3.3 and directly correlates with gene activity. H3.3 depletion led to reduced levels of NuRD at sites previously occupied by H3.3, as well as a global decrease in histone marks associated with gene activation. Our results demonstrate the importance of H3.3 in the maintenance of the cellular epigenetic landscape and reveal a highly prevalent interaction between the histone variant H3.3 and the multiprotein complex NuRD.
Chromosome Cohesion and Condensation in Xenopus Egg Extracts
Authors: da Silva Eulália M.L. , Rankin Susannah
Published: September 2018

Chromosome structure in both interphase and M-phase cells is strongly influenced by the action of the cohesin and condensin protein complexes. The cohesin complex tethers the identical copies of each chromosome, called sister chromatids, together following DNA replication and promotes normal interphase chromosome structure and gene expression. In contrast, condensin is active largely in M phase and promotes the compaction of individual chromosomes. The Xenopus egg extract system is uniquely suited to analyze the functions of both complexes. Egg extracts, in which the cell cycle state can be manipulated, contain stockpiles of nuclear proteins (including condensin and cohesin) sufficient for the assembly of thousands of nuclei per microliter. Extract prepared from unfertilized eggs is arrested by the presence of cytostatic factor (CSF) in a state with high levels of M-phase kinase activity, but can be stimulated to enter interphase, in which DNA replication occurs spontaneously. For cohesion assays, demembranated sperm nuclei are incubated in interphase extract, where they undergo rapid and synchronous DNA replication and cohesion establishment through the recruitment of proteins and other factors (e.g., nucleotides) from the extract. Sister chromatid cohesion is assessed by then driving the extract into M phase by the addition of fresh CSF-arrested extract. In contrast, because chromosome condensation occurs spontaneously in M-phase extracts, sperm nuclei are added directly to CSF extracts to assay condensation.
Microinjection of DNA Constructs into Xenopus Embryos for Gene Misexpression and cis-Regulatory Module Analysis
Authors: Yasuoka Yuuri , Taira Masanori
Published: September 2018

Introducing exogenous DNA into an embryo can promote misexpression of a gene of interest via transcription regulated by an attached enhancer-promoter. This protocol describes plasmid DNA microinjection into Xenopus embryos for misexpression of genes after zygotic gene expression begins. It also describes a method for coinjecting a reporter plasmid with mRNA or antisense morpholinos to perform luciferase reporter assays, which are useful for quantitative analysis of cis-regulatory sequences responding to endogenous or exogenous stimuli in embryos.
Cleavage Blastomere Deletion and Transplantation to Test Cell Fate Commitment in Xenopus
Authors: Moody Sally A.
Published: September 2018

Fate maps identify the precursors of an organ, and tracing the members of a blastomere lineage over time shows how its descendants come to populate that organ. The fates of the individual blastomeres of the two- to 32-cell Xenopus embryo have been fully mapped to reveal which cells are the major contributors to various cell types, tissues, and organs. However, because these fate maps were produced in the normal embryo, they do not reveal whether a precursor blastomere is competent to give rise to additional tissues or is already committed to its fate-mapped repertoire of descendants. To identify the mechanisms by which a cell's fate is committed, one needs to expose the cell to different experimental environments. If the cell's fate is determined, it will express its normal fate or gene expression profile in novel environments, whereas if it is not yet determined it will express different fates or gene expression profiles when exposed to novel external factors or neighboring cells. This protocol describes two techniques for testing cell fate commitment: single cell deletion and single cell transplantation. Deleting a blastomere allows one to test whether the deleted cell is required for the remaining cells to produce their normal, specific cell fates. Transplanting a blastomere to a novel location in a host embryo allows one to test whether the transplanted cell is committed to produce its normal fate-mapped repertoire, or whether it is still competent to respond to novel cell–cell interactions.
Assessing Antibody Responses to Pathogens or Model Antigens in Xenopus by Enzyme-Linked Immunosorbent Assay (ELISA)
Authors: Andino Francisco De Jesús , Robert Jacques
Published: September 2018

Xenopus laevis-specific monoclonal antibodies recognize IgM and IgY antibodies not only from X. laevis but also X. tropicalis as well as a variety of amphibian species including Ranidae, Bufonidae, and even some salamanders. These reagents are very useful to assess antibody responses from the serum or other animal secretions (e.g., peritoneal fluid). We present here an enzyme-linked immunosorbent assay (ELISA) optimized for amphibians that permits users to detect and titrate the presence of each type of antibody (IgM and IgY) produced against particular pathogens (e.g., virus, bacteria, or fungus) or antigens (e.g., DNP-KLH).
Studies of Limb Regeneration in Larval Xenopus
Authors: Mescher Anthony L. , Neff Anton W.
Published: September 2018

A basic protocol is given for animal maintenance and surgery in studies of hindlimb regeneration in larval Xenopus laevis. Unlike urodele limbs, those of larval frogs typically show much more variation in the extent of regeneration after amputation. Such variation can be reduced by optimizing the conditions of larval maintenance to regulate the rates of growth and development, by selecting only larvae with normal rates of growth and morphological development for experimental use, and by attention to precision and consistency in the proximo–distal level of surgical amputation.
Infrared Laser-Mediated Gene Induction at the Single-Cell Level in the Regenerating Tail of Xenopus laevis Tadpoles
Authors: Hasugata Riho , Hayashi Shinichi , Kawasumi-Kita Aiko , Sakamoto Joe , Kamei Yasuhiro , Yokoyama Hitoshi
Published: September 2018

We describe a precise and reproducible gene-induction method in the amphibian, Xenopus laevis. Tetrapod amphibians are excellent models for studying the mechanisms of three-dimensional organ regeneration because they have an exceptionally high regenerative ability. However, spatial and temporal manipulation of gene expression has been difficult in amphibians, hindering studies on the molecular mechanisms of organ regeneration. Recently, however, development of a Xenopus transgenic system with a heat-shock-inducible gene has enabled the manipulation of specific genes. Here, we applied an infrared laser-evoked gene operator (IR-LEGO) system to the regenerating tail of Xenopus tadpoles. In this method, a local heat shock by laser irradiation induces gene expression at the single-cell level. After amputation, Xenopus tadpoles regenerate a functional tail, including spinal cord. The regenerating tail is flat and transparent enabling the targeting of individual cells by laser irradiation. In this protocol, a single neural progenitor cell in the spinal cord of the regenerating tail is labeled with heat-shock-inducible green fluorescent protein (GFP). Gene induction at the single-cell level provides a method for rigorous cell-lineage tracing and for analyzing gene function in both cell-autonomous and noncell-autonomous contexts. The method can be modified to study the regeneration of limbs or organs in other amphibians, including Xenopus tropicalis, newts, and salamanders.
Methods for Examining Lens Regeneration in Xenopus
Authors: Henry Jonathan J. , Perry Kimberly J. , Hamilton Paul W.
Published: September 2018

Some vertebrates are able to regenerate the lens following its removal. This includes species in the genus Xenopus (i.e., X. laevis, X. tropicalis, and X. borealis), the only anurans known to undergo lens regeneration. In Xenopus the regenerated lens is derived de novo from cells located within the basal-most layer of the larval corneal epithelium, and is triggered by factors provided by the neural retina. In larval frogs the corneal epithelium is underlain by an endothelium separated from the corneal epithelium except for a small central attachment (i.e., the “stromal-attracting center”). This connection grows larger as the stroma forms and the frogs approach metamorphosis. Here we provide instructions for performing lentectomies (removal of the original lens) to study lens regeneration.
Calculating the Degradation Rate of Individual Proteins Using Xenopus Extract Systems
Authors: McDowell Gary S. , Philpott Anna
Published: September 2018

The Xenopus extract system has been used extensively as a simple, quick, and robust method for assessing the stability of proteins against proteasomal degradation. In this protocol, methods are provided for assessing the half-life of in vitro translated radiolabeled proteins using Xenopus egg or embryo extracts.
Reconstituting Nuclear and Chromosome Dynamics Using Xenopus Extracts
Authors: Rankin Susannah
Published: September 2018

Extracts prepared from the eggs of frogs, particularly Xenopus species, have provided critical material for seminal studies of nuclear and chromosome dynamics over several decades. Their usefulness for these types of analyses lies in several important characteristics: stockpiled nuclear components, absence of endogenous DNA, and intact and functioning signaling networks. These factors have allowed detailed molecular analyses of many aspects of chromosome biology, including DNA replication, checkpoint signaling, epigenetic control, and chromosome condensation, cohesion, and segregation. In this introduction, the preparation and application of Xenopus egg extracts for the study of chromosomes and chromatin are described in detail.
The HEPS project
Authors: Jiao Yi , Xu Gang , Cui Xiao-Hao , Duan Zhe , Guo Yuan-Yuan , He Ping , Ji Da-Heng , Li Jing-Yi , Li Xiao-Yu , Meng Cai , Peng Yue-Mei , Tian Sai-Ke , Wang Jiu-Qing , Wang Na , Wei Yuan-Yuan , Xu Hai-Sheng , Yan Fang , Yu Cheng-Hui , Zhao Ya-Liang , Qin Qing
Published: September 2018

The High Energy Photon Source (HEPS), a 6 GeV green-field diffraction-limited storage ring light source, will be built in Beijing, China. The HEPS design has been evolving for about ten years, and is now mostly finished and ready for construction. The storage ring is based on a modified hybrid seven-bend achromat (7BA) design, where bending magnets with reverse bending angles and longitudinal gradients are adopted to reach an ultralow natural emittance of 34.2 pm with a circumference of 1360.4 m. The central slice of the dipole in the middle of the modified hybrid 7BA, with flexible magnetic field, is used as the source of the bending-magnet beamline. Moreover, alternating high- and low-beta sections are specially designed to generate and deliver X-ray synchrotron radiation with high brightness of 5 × 1022 photons s−1 mm−2 mrad−2 (0.1% bandwidth)−1. Here, the HEPS storage ring design and solutions to the challenges inherent in this ultralow-emittance design are presented.
Rapid parameter identification and control of an induction machine
Authors: Nell Martin Marco , von Pfingsten Georg , Hameyer Kay
Published: September 2018

Purpose

Traction applications, e.g. the IMs are mainly operated by field-oriented control (FOC). This control technique requires an accurate knowledge of the machine’s parameters, such as the main inductance, the leakage inductances and the stator and rotor resistance. The accuracy of the parameters influences the precision of the calculated rotor flux and the rotor flux angle and the decoupling of the machine’s equations into the direct and quadrature coordinate system (dq-components). Furthermore, the parameters are used to configure the controllers of the FOC system and therefore influence the dynamic behavior and stability of the control.

Design/methodology/approach

In this paper, three different methods to calculate the machine’s parameters, in an automated and rapid procedure with minimal measuring expenditure, are analyzed and compared. Moreover, a method to configure a control that reduces the overall Ohmic losses of the machine in every torque speed operation point is presented. The machine control is configured only with the identified machine parameter.

Findings

Simulations and test bench measurements show that the evolutionary strategy is able to identify the electrical parameters of the machine in less time and with low error. Moreover, the controller is able to control the torque of the machine with a deviation of less than 2 per cent.

Originality/value

The most significant contribution of the research is the potential to identify the machine parameter of an induction motor and to configure an accurate control with these parameters.
Emirates Dates: a case of growth strategy dilemma
Authors: Zamberi Ahmad Syed , Rahim Abu Bakar Abdul
Published: September 2018

Subject area

Strategic marketing, Business strategy, Product diversification strategy and/or Market entry strategy.

Study level/applicability

This case is useful for undergraduate and postgraduate students who are pursuing majors in marketing, business management and/or strategic management.

Case overview

The Emirates Dates Factory commenced operations in 1989 in Ras Al Khaimah, United Arab Emirates (UAE), as a 100 per cent equity held by Mr Abdullah Al Shamsi. Over time, it has become one of the best and renowned factory for date production and processing. Emirates Dates derives its strength from its own plantations in Ras Al Khaimah and Al Ain, as well as from a wide variety of date products that it develops, including date syrup, dates in different packing and stuffed dates. The company seeks to be the leader of dates production and processing in terms of sales. However, the management is facing issues pertaining to determining the area of growth that it should pursue. This case study illustrates the growth options that Emirates Dates could pursue along with its opportunities and challenges that the firm faces.

Expected learning outcomes

This case study expose student to Ansoff growth matrix in general and the application of the market penetration strategy in specific. Accordingly, the case illustrates how one could develop other growth strategies to improve its revenues through product diversification and/or market development.

Supplementary materials

Teaching Notes are available for educators only. Please contact your library to gain login details or email support@emeraldinsight.com to request teaching notes.

Subject code

CSS 11: Strategy.
Quality higher education drives employability in the Middle East
Authors: Nauffal Diane , Skulte-Ouaiss Jennifer
Published: September 2018

Purpose

The purpose of this paper is to analyse and explain the high rates of employability of one group of Middle East youth by focussing on liberal arts and soft skills education as an integral part of quality higher education.

Design/methodology/approach

This paper employs the survey research method using questionnaires, focus groups and interviews to understand the labour market dynamics in Lebanon and explore factors that correlate positively with gainful employment with a special focus on the graduates of an institution that emphasises the liberal arts and soft skills training.

Findings

The paper finds that quality higher education – particularly with a focus on soft skills and internships – boosts the potential of graduates to secure their first jobs after graduation.

Research limitations/implications

Reliable data on higher education, employability and youth are scarce in Lebanon and the region. The paper is based on one labour market study in Lebanon while seeking to extrapolate to Lebanese youth as a whole as well as reflect on employability and youth in the Middle East region.

Practical implications

The paper demonstrates support for improving quality in higher education as well as making soft skills training and the liberal arts critical components for increased employability of youth in Lebanon and the Middle East.

Originality/value

The paper is innovative in its reliance on primary data from a labour market survey as such data are scarce in Lebanon. In addition, advocacy for soft skills training and the liberal arts in the midst of focus on science, technology, engineering and mathematics and other professional education at the university level is rare in the Middle East.
The increased international propensity of serial entrepreneurs demonstrating ambidextrous strategic agility
Authors: Vaillant Yancy , Lafuente Esteban
Published: September 2018

Purpose

The purpose of this paper is to analyze whether business owners that simultaneously demonstrate past entrepreneurial experience and process agility have greater export propensity levels.

Design/methodology/approach

The proposed hypotheses are tested using binary choice models relating past entrepreneurial experience and reported process agility on a unique sample of 246 Catalan business owners for the year 2010.

Findings

Consistent with the theoretical arguments on the relevance of generative-based cognitive agility, the results of this paper reveal that serial entrepreneurs demonstrate a greater export propensity. Additionally, the authors found that serial entrepreneurs who also demonstrate process agility show superior export propensity levels, compared to the group of business owners outside this ambidextrous group (first-time business owners without process agility).

Research limitations/implications

The findings of this study indicate that traits characterizing international marketing agility, decisional speed and accuracy are also linked with greater export propensity levels. The added export market expansion resulting from the opportunity responsiveness of serial entrepreneurs is found to be amplified by the accuracy of internal adaptation capabilities of process agility.

Practical implications

Therefore, the promotion of ambidextrous strategic agility coming from the complementarities between the benefits of entrepreneurial experience and adaptive process abilities is essential for increasing businesses’ internationalization.

Originality/value

The paper contributes to the literature by further exploring the influence of different sources of agility on the internationalization of entrepreneurial ventures and opens a link between entrepreneurs prone toward export market expansion and international marketing agility.
The European deposit insurance game plan
Authors: Kiriazidis Theo
Published: September 2018

Purpose

This paper aims to analyze the development of European Deposit Insurance (DI) and assess the recent development at the EU level to establish a European Deposit Insurance Scheme (EDIS) in the context of a more integrated financial framework: the Banking Union (BU).

Design/methodology/approach

The author uses literature review and empirical evidence to analyze the dynamic interaction among European governments in an effort to attract aggressive deposits with severe repercussion for financial stability.

Findings

The paper argues that a liquidity providing EDIS would render regulatory subsidy and rent-seeking behavior persisting by allowing national policies to be pursued with considerable discretionary power and in the context of increasing competition for deposits. This would run contrary to the BU objectives and constitute a major failure of the program.

Practical implications

The findings of the study can be helpful in understanding the DI policies pursued by European governments and their implications.

Originality/value

To the best of the authors’ knowledge, this is the first study that examines the interactions among European governments in pursuing DI policies and assesses the implications of EDIS.
The SEC Speaks 2018: the US Securities and Exchange Commission’s current priorities and conference overview
Authors: Russelo Gerald J. , Cohen Stephen L. , Sanchez Jose F.
Published: September 2018

Purpose

This paper aims to highlight certain comments made by US Securities and Exchange Commission (SEC) officials, which may provide insight into compliance and enforcement issues that may be important for market participants, including broker-dealers, investment advisors and reporting companies, in the future.

Design/methodology/approach

This paper explains comments made by SEC officials and highlights potential regulatory issues based on past experiences of attorneys within the firm, past comments made by the SEC and Financial Industry Regulatory Authority and past regulatory exam results.

Findings

This paper summarizes remarks from the recent SEC Speaks 2018 Conference conducted by SEC officials related to the Commission’s regulatory and enforcement priorities. Issuers, brokers, advisors and other financial organizations should familiarize themselves with the themes and guidance discussed at the Conference to prepare for regulatory compliance challenges in the upcoming year.

Originality/value

Practical guidance from experienced securities and financial services lawyers.