bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution of male costs of copulation in sepsid flies (Diptera: Sepsidae)
Authors: Rohner Patrick T. , Shen Yoong Kai , Tuan Mindy J. M. , Meier Rudolf
Published: February 2018

Reproduction is well known to be costly for females, but longevity costs of copulations in males are still poorly understood. In particular, the effect of the number of copulations on male longevity is rarely considered. Work on black scavenger flies (Diptera: Sepsidae) showed contrasting results: in Saltella sphondylii the number of copulations is strongly negatively correlated with male longevity, whereas in Sepsis cynipsea mated males did not suffer from reduced longevity. Here we summarize the findings of several studies covering four additional species of sepsid flies from across the phylogenetic tree of sepsids to better understand the evolution of male reproductive costs in this clade. After accounting for the mating system differences between species, we find no evidence for longevity costs in Allosepsis sp., Sepsis fulgens and Themira superba, while in Saltella nigripes multiple copulations drastically reduced longevity. Mapping this trait onto the most current phylogenetic hypothesis for Sepsidae suggests that male cost in Saltella is derived while there is an absence of longevity costs for all other sepsids. We discuss the origin of this novel longevity cost in Saltella in the context of a change in their reproductive strategy, namely the evolution of high polygynandry coupled with unusually brief copulations.
An evolutionary-conserved Wnt3/β-catenin/Sp5 feedback loop restricts head organizer activity inHydra
Authors: Vogg Matthias C. , Beccari Leonardo , Iglesias Ollé Laura , Rampon Christine , Vriz Sophie , Perruchoud Chrystelle , Wenger Yvan , Galliot Brigitte
Published: February 2018

TheHydrapolyp regenerates its head by transforming the gastric tissue below the wound into a head organizer made of two antagonistic cross-reacting components. The activator, previously characterized asWnt3, drives apical differentiation by acting locally and auto-catalytically. The uncharacterized inhibitor, produced under the control of the activator, prevents ectopic head formation. By crossing RNA-seq data obtained in aβ-catenin(RNAi) screen performed in planarians and a quantitative analysis of positional and temporal gene expression inHydra, we identified Sp5 as a transcription factor that fulfills the head inhibitor properties: a Wnt/β-catenin inducible expression, a graded apical-to-basal expression, a sustained up-regulation during head regeneration, a multi-headed phenotype when knocked-down, a repressing activity on Wnt3 expression. In mammalian cells,Hydraand zebrafish Sp5 repressWnt3promoter activity whileHydra Sp5also auto-activates its expression, possibly via β-catenin and/or Tcf/Lef1 interaction. This work identifies Sp5 as a novel potent feedback loop inhibitor of Wnt/β-catenin signaling across eumetazoans.
Fanconi Anemia FANCM/FNCM-1 and FANCD2/FCD-2 are required for maintaining histone methylation levels and interact with the histone demethylase LSD1/SPR-5 inC. elegans
Authors: Kim Hyun-Min , Beese-Sims Sara E. , Colaiácovo Monica P.
Published: February 2018

The histone demethylase LSD1 was originally discovered as removing methyl groups from di- and monomethylated histone H3 lysine 4 (H3K4me2/1), and several studies suggest it plays roles in meiosis as well as epigenetic sterility given that in its absence there is evidence of a progressive accumulation of H3K4me2 through generations. In addition to transgenerational sterility, growing evidence for the importance of histone methylation in the regulation of DNA damage repair has attracted more attention to the field in recent years. However, we are still far from understanding the mechanisms by which histone methylation is involved in DNA damage repair and only a few studies have been focused on the roles of histone demethylases in germline maintenance. Here, we show that the histone demethylase LSD1/CeSPR-5 is interacting with the Fanconi Anemia (FA) protein FANCM/CeFNCM-1 based on biochemical, cytological and genetic analyses. LSD1/CeSPR-5 is required for replication stress-induced S-phase checkpoint activation and its absence suppresses the embryonic lethality and larval arrest observed infncm-1mutants. FANCM/CeFNCM-1 re-localizes upon hydroxyurea exposure and co-localizes with FANCD2/CeFCD-2 and LSD1/CeSPR-5 suggesting coordination between this histone demethylase and FA components to resolve replication stress. Surprisingly, the FA pathway is required for H3K4me2 maintenance regardless of the presence of replication stress. Our study reveals a connection between Fanconi Anemia and epigenetic maintenance, therefore providing new mechanistic insight into the regulation of histone methylation in DNA repair.
‘Big bang’ of B-cell development revealed
Authors: Murre Cornelis
Published: February 2018

Earlier studies have identified transcription factors that specify B-cell fate, but the underlying mechanisms remain to be revealed. Two new studies by Miyai and colleagues (pp. 112–126) and Li and colleagues (pp. 96–111) in this issue of Genes & Development provide new and unprecedented insights into the genetic and epigenetic mechanisms that establish B-cell identity.
Conserved microRNA targeting reveals preexisting gene dosage sensitivities that shaped amniote sex chromosome evolution
Authors: Naqvi Sahin , Bellott Daniel W. , Lin Kathy S. , Page David C.
Published: February 2018

Mammalian X and Y Chromosomes evolved from an ordinary autosomal pair. Genetic decay of the Y led to X Chromosome inactivation (XCI) in females, but some Y-linked genes were retained during the course of sex chromosome evolution, and many X-linked genes did not become subject to XCI. We reconstructed gene-by-gene dosage sensitivities on the ancestral autosomes through phylogenetic analysis of microRNA (miRNA) target sites and compared these preexisting characteristics to the current status of Y-linked and X-linked genes in mammals. Preexisting heterogeneities in dosage sensitivity, manifesting as differences in the extent of miRNA-mediated repression, predicted either the retention of a Y homolog or the acquisition of XCI following Y gene decay. Analogous heterogeneities among avian Z-linked genes predicted either the retention of a W homolog or gene-specific dosage compensation following W gene decay. Genome-wide analyses of human copy number variation indicate that these heterogeneities consisted of sensitivity to both increases and decreases in dosage. We propose a model of XY/ZW evolution incorporating such preexisting dosage sensitivities in determining the evolutionary fates of individual genes. Our findings thus provide a more complete view of the role of dosage sensitivity in shaping the mammalian and avian sex chromosomes and reveal an important role for post-transcriptional regulatory sequences (miRNA target sites) in sex chromosome evolution.
Place learning overrides innate behaviors in Drosophila
Authors: Baggett Vincent , Mishra Aditi , Kehrer Abigail L. , Robinson Abbey O. , Shaw Paul , Zars Troy
Published: February 2018

Animals in a natural environment confront many sensory cues. Some of these cues bias behavioral decisions independent of experience, and action selection can reveal a stimulus–response (S–R) connection. However, in a changing environment it would be a benefit for an animal to update behavioral action selection based on experience, and learning might modify even strong S–R relationships. How animals use learning to modify S–R relationships is a largely open question. Three sensory stimuli, air, light, and gravity sources were presented to individual Drosophila melanogaster in both naïve and place conditioning situations. Flies were tested for a potential modification of the S–R relationships of anemotaxis, phototaxis, and negative gravitaxis by a contingency that associated place with high temperature. With two stimuli, significant S–R relationships were abandoned when the cue was in conflict with the place learning contingency. The role of the dunce (dnc) cAMP-phosphodiesterase and the rutabaga (rut) adenylyl cyclase were examined in all conditions. Both dnc1 and rut2080 mutant flies failed to display significant S–R relationships with two attractive cues, and have characteristically lower conditioning scores under most conditions. Thus, learning can have profound effects on separate native S–R relationships in multiple contexts, and mutation of the dnc and rut genes reveal complex effects on behavior.
The beneficial effect of prior experience on the acquisition of spatial memory in rats with CA1, but not large hippocampal lesions: a possible role for schema formation
Authors: Ocampo Amber C. , Squire Larry R. , Clark Robert E.
Published: February 2018

Prior experience has been shown to improve learning in both humans and animals, but it is unclear what aspects of recent experience are necessary to produce beneficial effects. Here, we examined the capacity of rats with complete hippocampal lesions, restricted CA1 lesions, or sham surgeries to benefit from prior experience. Animals were tested in two different spatial tasks in the watermaze, the conventional watermaze task and delayed match-to-position. The two lesions impaired performance in both tasks when rats had no prior experience. However, when given prior training with one task, CA1 lesions had no effect on performance in the other task. In contrast, rats with hippocampal lesions did not benefit from prior training. The findings show that prior experience can benefit learning even when the previously learned task and a new task are quite different. The concept of schema may be useful for understanding the benefits of prior experience.
Deleting HDAC3 rescues long-term memory impairments induced by disruption of the neuron-specific chromatin remodeling subunit BAF53b
Authors: Shu Guanhua , Kramár Enikö A. , López Alberto J. , Huynh Grace , Wood Marcelo A. , Kwapis Janine L.
Published: February 2018

Multiple epigenetic mechanisms, including histone acetylation and nucleosome remodeling, are known to be involved in long-term memory formation. Enhancing histone acetylation by deleting histone deacetylases, like HDAC3, typically enhances long-term memory formation. In contrast, disrupting nucleosome remodeling by blocking the neuron-specific chromatin remodeling subunit BAF53b impairs long-term memory. Here, we show that deleting HDAC3 can ameliorate the impairments in both long-term memory and synaptic plasticity caused by BAF53b mutation. This suggests a dynamic interplay exists between histone acetylation/deacetylation and nucleosome remodeling mechanisms in the regulation of memory formation.
Determinants of ethical work behaviour of Malaysian public sector auditors
Authors: Ismail Suhaiza , Yuhanis Nursia
Published: February 2018

Purpose

The purpose of this paper is to investigate factors affecting ethical work behaviour among Malaysian public sector auditors. Based on Hunt and Vitell model, there are four research objectives for this study: to investigate the influence of ethical climate on public sector auditors ethical work behaviour; to examine the effect of professional commitment on ethical work behaviour of public sector auditors; to investigate the effect of corporate ethical values (CEV) on ethical work behaviour of public sector auditors; and to examine the effect of ethical ideology on ethical work behaviour of public sector auditors.

Design/methodology/approach

The respondents of the study were public sector auditors of National Audit Department in Malaysia. Using a survey questionnaire comprising instruments about the ethical climate, CEV, professional commitment, ethical ideology and organisational misbehaviour, a total of 382 were received and usable. In achieving the research objectives, multiple regressions were performed.

Findings

The results reveal that ethical work behaviour among public sector auditors in Malaysia is influenced by law and independence ethical climate, professional commitment, CEV and both idealism and relativism ethical ideology.

Originality/value

The present study provides new additional empirical evidence on determinants of ethical work behaviour of auditors in public sector from a developing economy (i.e. Malaysia) which is currently limited.
Perception of hospital environment before and after relocation
Authors: Reijula Jori , Ruohomäki Virpi
Published: February 2018

Purpose

This study assessed employees’ perceptions of their hospital work environment, its quality and functionality, as well as their satisfaction and well-being both before and after relocation within the hospital campus.

Design/methodology/approach

The study was carried out in a Finnish University Hospital. Employees from the anesthesia, orthopedics and physiatrics department took part in the study. The data were collected from the employees with online questionnaires before and after the relocation. The statistical differences between the questionnaire variables were analyzed using the Chi-square test.

Findings

Remarkable improvements in the quality of the new workplace included ability to adjust temperature, ventilation and furniture, ability to see out of windows, accessibility, number of meeting rooms, places to discuss confidential matters, quality of interior design, improved work satisfaction and desire to implement Lean. Significant deteriorations after relocation included unsettled work environment, impaired quality of cooperation and decreased interaction between employees.

Originality/value

This study discovered several improvements in the new facilities that had a visible effect on the assessed employee satisfaction and well-being parameters. The paper contains new, significant information that is relevant to the hospital facilities management and provides insight about the pros and cons of relocation and wherein their focus should be placed.
Living where you work
Authors: Carswell Andrew T.
Published: February 2018

Purpose

This paper aims to examine whether property managers who live on-site within a residential apartment building provide a value-added benefit to the management in the form of cost control and revenue maximization.

Design/methodology/approach

This research uses two large US data sets that cover operational and financial data of apartment owners/operators and the financial and individual housing situations of renters themselves. The regression models developed were general linear models with operating expenses, rent collection and monthly rent paid as dependent variables, with on-site resident manager status as the experimental variable.

Findings

This research finds that the value of on-site property managers does not definitively maximize rent revenue, as expected. On-site property managers also don’t show significant reductions in operating expenses, although they are not cost centers either. Individual renter households do, however, pay a significant rent premium for units in communities with on-site personnel living there.

Research limitations/implications

The limitations of this research include the inability to merge the two data sets and the inability to measure the intangible attributes of the on-site residential manager’s experience.

Practical implications

As roughly 30 per cent of US rental apartment buildings have some form of on-site manager, this research has some practical implications for multifamily housing investors/owners, a highly visible US building sector.

Social implications

The action of hiring an on-site residential property manager also addresses issues related to the optimization and efficient allocation of human resources for property management companies.

Originality/value

This appears to be the first research addressing property managers who live at the site where they also work.
The NLS-based nonlinear grey Bernoulli model with an application to employee demand prediction of high-tech enterprises in China
Authors: Pei Lingling , Li Qin , Wang Zhengxin
Published: February 2018

Purpose

The purpose of this paper is to propose a new method based on nonlinear least squares (NLS) for solving the parameters of nonlinear grey Bernoulli model (NGBM(1,1)) and to verify the proposed model using the case of employee demand prediction of high-tech enterprises in China.

Design/methodology/approach

First of all, minimising the square sum of fitting error of grey differential equation of NGBM(1,1) is taken as the optimisation target and the parameters of classic grey model (GM(1,1)) are set as the initial value of parameter vector. Afterwards, the structural parameters and power exponents are solved by using the Gauss-Newton iteration algorithm so as to calculate the parameters of NGBM(1,1) under given rules for ceasing the algorithm. Finally, by taking the employee demand of high-tech enterprises in the state-level high-tech industrial development zone in China as examples, the validity of the new method is verified.

Findings

The results show that the parameter estimation algorithm based on the NLS method can effectively identify the power exponents of NGBM(1,1) and therefore can favourably adapt to the nonlinear fluctuations of sequences. In addition, the algorithm is superior to the GM(1,1) model, grey Verhulst model, and Quadratic-Exponential smoothing algorithm in terms of the simulation and prediction accuracy.

Research limitations/implications

Under the framework of solving parameters based on NLS, various aspects of NGBM(1,1) remain to be further investigated including background value, initial condition and variable structural modelling methods.

Practical implications

The parameter estimation algorithm based on NLS can effectively identify the power exponent of NGBM(1,1) and therefore it can favourably adapt to the nonlinear fluctuation of sequences.

Originality/value

According to the basic principle of NLS, a new method for solving the parameters of NGBM(1,1) is proposed by using the Gauss-Newton iteration algorithm. Moreover, by conducting the modelling case about employees demand in high-tech enterprises in China, the effectiveness and superiority of the new method are verified.
The effect of service charge responsibilities on tenants’ leasing experience and satisfaction
Authors: Halvitigala Dulani
Published: February 2018

Purpose

Despite the growing diversity of lease structures in different global economies, the existing literature related to property service charge mechanisms has been largely confined to the UK property market. This study aims to examine tenants’ perceptions, experiences and satisfaction with being responsible for service charges in New Zealand, where major office submarkets are dominated by alternative forms of leases with different service charge responsibilities.

Design/methodology/approach

The study uses a structured survey of 107 major tenants of New Zealand’s listed property trust-owned properties located in Auckland (where net leases dominate) and Wellington (where gross leases dominate) complemented by ten in-depth interviews with senior property managers of tenant organisations. The collected data were analysed using various statistical tests and thematic analysis.

Findings

The results identify that tenants who are directly responsible for service charges are significantly more dissatisfied with their operating expenses (OPEX) responsibilities than tenants who do not have direct service charge responsibilities. They are dissatisfied with the interpreting, budgeting, calculating, accounting, allocating and auditing processes in the service charge management process. Tenants who are directly responsible for service charges are significantly more dissatisfied with the operation and maintenance procedures of their buildings and have weaker relationship strengths with landlords. Tenant perceptions of being responsible for service charges vary with their power relationship with the landlord, lease expectations and priorities, financial constraints, willingness to take part in the management of the premises and trust in the landlord.

Originality/value

This research highlights the importance of understanding the complexity of service charge mechanisms in countries where there are no regulations or codes of practice governing them and their impact on tenant leasing behaviours, experiences and satisfaction. Here, the importance of developing more widely applicable codes of practice representing countries with different lease environments is highlighted. The findings also emphasise the importance of understanding the dynamics of key market agents that actively create lease environments and how they interact and behave within these contexts.
The role of compliance for organisational change
Authors: Busse Ronald , Doganer Ufuk
Published: February 2018

Purpose

Fuelled by the latest scandals at Siemens, VW or Walmart, there is a lively debate on the role of compliance and ethics programmes. Unlike large corporations, small and medium-sized enterprises (SMEs) arguably tend to underestimate their significance and lag behind. Hence, the purpose of this paper is to shed light on the process of introducing compliance codes and its effects on employee acceptance and performance.

Design/methodology/approach

In line with the qualitative methodology, the authors conducted 12 in-depth interviews with German SME employees which the authors evaluated with the qualitative content analysis.

Findings

As for the major contribution, results indicate the emergence of a lack of understanding, anger, anxiety and operational performance losses – both at the individual and the corporate level – especially when employees feel uninvolved in the initial introduction stadium.

Originality/value

Practicing managers may benefit from the recommendation to facilitate staff involvement at earlier stages. As for theory advancement, the authors draw on Kotter’s (2007) long surviving “Eight Steps Change Management Model” and find significant support for shifting the spotlight of attention towards the first four phases. The authors discuss the original value of the research, admit limitations and illuminate some promising future research trajectories.
Planned organisational change management
Authors: Rosenbaum David , More Elizabeth , Steane Peter
Published: February 2018

Purpose

The purpose of this paper is to identify the development of planned organisational change models (POCMs) since Lewin’s three-step model and to highlight key linkages between them.

Design/methodology/approach

A total of 13 commonly used POCMs were identified and connections with Lewin’s three-step framework and associated process attributes were made, reflecting the connections between these models and Lewin.

Findings

The findings show that first Lewin’s three-step model represents a framework for planned change; however, these steps could not be viewed in isolation of other interrelated processes, including action research, group dynamics, and force field analysis. These process steps underpin the iterative aspects of his model. Second, all 13 POCMs have clearly identified linkages to Lewin, suggesting that the ongoing development of POCMs is more of an exercise in developing ongoing procedural steps to support change within the existing framework of the three-step model.

Research limitations/implications

The authors recognise that the inclusion of additional POCMs would help strengthen linkages to Lewin. The findings from this paper refocus attention on the three-step model, suggesting its ongoing centrality in planned organisational change rather than it being dismissed as an historical approach from which more recently developed models have become more relevant.

Practical implications

This paper presents opportunities for organisational change management researchers to challenge their thinking with regard to the ongoing search for model refinement, and for practitioners in the design and structure of POCM.

Originality/value

An analysis of the ongoing relevance of Lewin and his linkage with modern POCMs assist in rationalising the broadening, and often confusing literature on change. This paper therefore not only contributes to filtering such literature, but also helps clarify the myriad of POCMs and their use.
Process factors affecting adhesion of encapsulation molding compounds
Authors: Liaw Yow-Ching , Chao Shou-Yen , Chou Jung-Hua
Published: February 2018

Purpose

The purpose of this paper is to determine the key process factors which affect the adhesion strength of encapsulation molding compounds (EMCs) to leadframes to obtain reliable components without any need to pretreat the leadframe surface.

Design/methodology/approach

EMCs were molded to Cu leadframes to experimentally quantify the effect of mold temperature, resin viscosity, leadframe oxidation and powder moisture on the adhesion force. Component reliability was assessed by PCT.

Findings

A higher mold temperature result in a larger adhesion force. The mold temperature of 175°C provides the largest process window. Leadframe oxidation can increase adhesion first, but then decrease it drastically with further oxidation. The powder moisture content has mixed effect on adhesion.

Practical implications

By molding at 175°C, limiting the wire bonding time and minimizing the powder moisture content, reliable components can be obtained without any need for leadframe surface pretreatment such as plasma cleaning or surface coating.

Originality/value

Quantify the key process factors which affect the adhesion of EMCs and reveal reason behind the current industrial practice of using the mold temperature of 175°C.
Photolithography-free PDMS stamps for paper microdevice fabrication
Authors: Montgomery R. Hunter , Phelan Kelsey , Stone Sawyer D. , Decuir Francois , Hollins Bryant C.
Published: February 2018

Purpose

This paper aims to investigate the applicability of 3D-printed molds to be used as a substitute for photolithography in the formation of polymer-based stamps. It proposes leveraging 3D printing as a rapid prototyping tool to be applied to microfluidic fabrication.

Design/methodology/approach

Different designs are created using computer-aided design (CAD) software and printed via Makerbot 3D printer. The molds serve as negative reliefs for a PDMS stamp. The stamp is used to apply paraffin wax to chromatography paper, creating hydrophobic barriers and hydrophilic channels. The minimum functional channel widths and barrier widths are determined for the method.

Findings

The method is demonstrated to be effective for bypassing the more cost-prohibitive photolithography approach for rapid paper microdevice fabrication. This approach produces functional channels that can be used for on-chip analytical assays. The minimum functional barrier widths and minimum functional channel widths are in good agreement with other published methods for paper-based microchannel fabrication.

Research limitations/implications

The approach cannot generate the high-resolution structures possible with photolithography. Therefore, if higher resolutions are needed for a particular application, this approach is not the best.

Practical implications

The simplicity of the approach introduces an affordable method to create disposable devices that can be used at the point of testing.

Originality/value

The paper satisfies a need for inexpensive, rapid prototyping of paper-based devices. The method is simple and can be used as a tool for introducing labs to microfluidics research.
Minimizing voids for a material extrusion-based process
Authors: Eiliat Hasti , Urbanic Ruth Jill
Published: February 2018

Purpose

After experimental testing, it was recognized that a component’s strength relationship with respect to the volume material usage is inconsistent and that failures occurred in regions of voids. The purpose of this study is to present an optimal toolpath for a material extrusion process to minimize voids and discontinuities using standard parameters and settings available for any given machine.

Design/methodology/approach

To carry out this study, a literature review was performed to understand the influence of the build parameters. Then, an analysis of valid parameter settings to be targeted was performed for a commercial system. Fortus 400 machine build parameters are used for the case studies presented here. Optimal relationships are established based on the geometry and are to be applied on a layer-by-layer or sub-region basis and available machine build options. The component geometry is analyzed and decomposed into build regions. Matlab® is used to determine a standard (available) toolpath parameters with optimal variables (bead height, bead width, raster angle and the airgap) for each layer/build region.

Findings

It was found that the unwanted voids are decreased by up to 8 per cent with the new model. The final component will contain multiple bead widths and overlap conditions, but all are feasible as the available machine solutions are used to seed the model.

Practical implications

Unwanted voids can create failure points. Introducing an optimization solution for a maximized material fill strategy using existing build options will reduce the presence of voids and will eliminate “chimneys” or a void present in every layer of the component. This solution can be implemented using existing machine-toolpath solutions.

Originality/value

This study demonstrates that existing build settings and toolpath strategies can be used to improve the interior fill by performing targeted optimization strategies for the build parameters.
Influence of laser parameters on the surface morphology of slurry-based Al2O3 parts produced through selective laser melting
Authors: Zhang Kai , Liu Tingting , Liao Wenhe , Zhang Changdong , Yan Yishuai , Du Daozhong
Published: February 2018

Purpose

The purpose of this paper is to obtain high-performance ceramics and enrich additive manufacturing of ceramic parts. Also, a new manufacturing technique based on slurry by selective laser melting (SLM) was studied, which has some significant advantages compared to indirect selective laser sintering of ceramic powders.

Design/methodology/approach

To study the effect of laser parameters on the surface morphology and melting state of pure Al2O3 ceramics, laser power varied between 100 and 200 W and scan speed varied between 60 and 90 mm/s.

Findings

Experimental results show that Al2O3 slurry melts completely when the laser power is about 200 W and the scanning speed is 90 mm/s. Surface quality cannot be improved effectively by changing the scanning speed. However, surface quality improves when the laser power is 200∼205 W and energy density is 889∼911 J/mm3. Thermocapillary convection was observed during SLM. By changing the temperature gradient, streak convection and flowing Bénard cells were obtained during SLM of Al2O3 slurry.

Originality/value

It is feasible to produce slurry ceramic parts without binders through SLM. Increasing the laser power is the most effective way to fully melt the ceramics. Complex thermocapillary convection was observed during this new process; it may be used to produce crystals.
Fournier's gangrene: A 10‐year review and validation of mortality predictors in a Hong Kong major regional centre
Authors: Chan Brian Yin‐On , Wong Ben Wui‐Bun , Lo Kelly Ka‐Yee , Yim Carmen , Tse Cyrus Tak‐Yin
Published: February 2018

Aim

Fournier's gangrene (FG) is a surgical emergency necessitating urgent debridement and aggressive antimicrobials. Early recognition of high‐risk patients enables timely critical care, but controversies existed in common scoring systems. No local data are available on their applicability and valid prognosticating factors; therefore, the aim of the present study was to improve triage and mortality.

Patients and Methods

Fifty patients with FG from 2006 to 2015 were retrospectively reviewed. Baseline demographics, physiological and laboratory values, management options, and parameters in established scoring systems were compared between survivors and nonsurvivors via univariate analyses. Receiver operating characteristic curves for the three commonest indexes were plotted to evaluate their diagnostic performance.

Results

Mortality was 20 per cent, compatible with international literature. Nonsurvivors had greater median age (63 vs 53 years, P = 0.05), smoking habit (70 vs 30 per cent, P = 0.03), diabetes (80 vs 38 per cent, P = 0.03), immunosuppression (100 vs 68 per cent, P = 0.046), orchidectomy (30 vs 3 per cent, P = 0.022) and serum creatinine (1.2 vs 0.91 mg/dL, P = 0.042) and lower haematocrit (31 vs 36 per cent, P = 0.006). No survival benefit was observed in the construction of defunctioning stoma and suprapubic catheterization. For scoring systems, no difference in translated score levels was seen. The area under the curve of the FG severity index was 0.798, whereas that for the simplified and Uludag versions were 0.588 and 0.833, respectively; all were statistically not significant.

Conclusion

Smokers and elderly, diabetic, or immunocompromised patients, those with a higher creatinine or lower haematocrit level and those requiring orchidectomy had a poorer prognosis and could benefit from intensive care. Current scoring systems either perform poorly or have troublesome frontline application. The present study is the first local study of such intent.
Wireless ambulatory urodynamic study: A 6‐year retrospective review in a tertiary paediatric urological referral centre
Authors: Hung Judy W.S. , Chung Kenneth L.Y. , Yam Felix S.D. , Leung Yvonne C.L. , Lau Ambrose K.W. , Ng Robin B.C. , Liu Clarence S.W. , Tang Paula M.Y. , Chao Nicholas S.Y. , Leung Michael W.Y.
Published: February 2018

Aim

Urodynamic study is a functional assessment of the lower urinary tract. It has an essential role in the evaluation of paediatric patients with lower urinary tract symptoms, be it due to neurogenic or nonneurogenic causes. Since 2013, we have introduced wireless ambulatory form of the study. In the present study, we performed a baseline review of our paediatric urodynamic service within a 6‐year period to determine its indications, outcomes and complications.

Patients and Methods

A retrospective review of all urodynamic studies performed between August 2011 and April 2017 in patients <18 years of age was performed. Demographics, including age and sex, and indications were collected. Urodynamic parameters, including type of catheter used, presence of detrusor overactivity, bladder compliance, end‐fill detrusor pressure, maximum voiding detrusor pressure, postvoid residual bladder volume and bladder emptying efficiency, were collected. Complications from either catheter insertion or the urodynamic study itself were documented.

Results

Sixty‐seven studies were done between the study period in 55 patients (16 females and 39 males). Fifty‐eight ambulatory studies with natural and conventional fill were performed since 2013. The median age at study was 2.1 years (range 0.1–17 years). Indications included myelodysplasia (61 per cent, n = 41 studies), bilateral high‐grade vesicoureteric reflux (18 per cent, n = 12), dysfunctional voiding (15 per cent, n = 10) and patient with posterior urethral valve (6 per cent, n = 4). Suprapubic catheters were used in 62 studies in patients with urethral sensation, and transurethral catheters were used in five studies. Overall, 53 studies were considered abnormal (79.1 per cent). No complications resulted from suprapubic catheter insertion or urodynamic studies.

Conclusion

Ambulatory urodynamic studies using our unit’s protocol remain safe and child friendly, with minimal complications and high patient and parent satisfaction.
Disturbance of Fluid and Electrolyte Transport in Cystic Fibrosis Epithelia
Authors: BIJMAN J.
Published: February 2018

Studies of the disease CF suggest that the basic defect is related to impaired electrolyte movement in the epithelia of a variety of organs with exocrine function. The disturbances of electrolyte secretion in the organs classically involved in CF range from 1) a decrease in secretion‐ or uptake of chloride ions in all the organs studied; 2) an increase in sodium uptake in nasal airway epithelium and 3) a decrease in bicarbonate output of the pancreas. In this review an overview is presented of the expression of the CF defect, the abnormalities of fluid and electrolyte secretion in each CF affected organ are considered in more detail with particular emphasis on the hormonal and neuronal (dys)regulation of ion transport systems in epithelial cells.
The Molecular Basis of Chloride Channel Dysregulation in Cystic Fibrosis
Authors: DE JONGE H. R.
Published: February 2018

The opening and closing of chloride (Cl−) channels in the apical membrane of epithelial cells is regulated by hormones, neurotransmitters and enterotoxins (intestine) acting through a variety of intracellular messengers, including cyclic nucleotides (cAMP, cGMP), calcium (Ca) and diacylglycerol (DAG). The chloride impermeability of epithelial membranes observed in cystic fibrosis (CF) patients does not result from a defect in the Cl− conducting properties of the channel or in channel recruitment but stems either from a defect in a key regulator of the channel, presumably a phosphoprotein, or from the hyperactivation of a channel closing mechanism, presumably a protein phosphatase or a down‐regulating protein kinase (i.e. protein kinase C). In vitro phosphorylation of isolated intestinal brush border membranes has revealed the existence of a 25000 molecular weight proteolipid (p25) acting as a cosubstrate for both cGMP‐ and cAMP‐dependent protein kinases and cross‐reacting with antibodies directed against the cytoplasmic tail of the band 3 anion exchanger from erythrocytes. The putative role of p25 in Cl− channel regulation and its relationship to an unidentified GTP‐binding protein recently implicated in Cl− channel activation is discussed on the basis of a regulatory model indicating potential sites of the CF defect at a molecular level.
Epithelial Cell Dysfunction in Cystic Fibrosis: Implications for Airways Disease
Authors: BOAT THOMAS F. , CHENG PI WAN
Published: February 2018

An important pathophysiologic factor in CF airways is the failure to clear poorly hydrated secretions. The water deficit in CF mucous secretions can now be ascribed to a fundamental defect of epithelial cell regulatory processes which promotes sodium reabsorption from surface liquids and interferes with chloride secretion onto the luminal surface. In addition, it is now known that CF airway epithelial cells oversulfate high molecular weight glycoconjugates, both secreted and cell surface‐associated. Oversulfation of glycoconjugates may contribute to the altered clearance properties of CF airways mucus and in addition could favor colonization of airways by organisms such as P. aeruginosa.
Host Response to Pseudomonas aeruginosa
Authors: DÖRING GERD
Published: February 2018

Patients with cystic fibrosis (CF) do not reveal a primary immune defect and respond with high numbers of functional polymorphonuclear leukocytes (PMN) and specific antibodies to lung infection with Pseudomonas aeruginosa. The mucoid character of P. aeruginosa, an altered epithelial cell surface, and high concentrations of PMN‐derived lysosomal enzymes contribute to impaired bacterial lung clearance and result in chronic infection. Released PMN‐elastase inactivates exotoxin A, the major toxin of P. aeruginosa, thus reducing its virulence. The imbalance between PMN‐proteinases and their inhibitors leads to lung tissue damage, impaired opsonophagocytosis, and T‐cell and B‐cell imbalance. New therapeutical concepts in CF therefore combine anti‐inflammatory drugs with effective antibiotics.
Gene Mapping in Cystic Fibrosis and Its Clinical Applications
Authors: WILLIAMSON ROBERT
Published: February 2018

Current techniques in molecular genetics have permitted the localisation of the mutation causing cystic fibrosis to chromosome 7q31, and allowed isolation of very tightly linked markers. It is possible to offer early prenatal diagnosis, carrier testing, and alteration of risk of unaffected partners in most cases. However, community‐wide definitive carrier testing and new methods of treatment await the isolation of the gene.
Letter: mucosal response in discriminating intestinal tuberculosis from Crohn's disease—when to look for it?
Authors: Sharma V. , Mandavdhare H. S. , Dutta U.
Published: February 2018

Linked content

This article is linked to Partap Mouli et al papers. To view these articles visit https://doi.org/10.1111/apt.13840 and https://doi.org/10.1111/apt.14535.
Editorial: the post‐Helicobacter stomach—not the same for cohorts and individuals. Authors’ reply
Authors: Kim N. , Hwang Y. J.
Published: February 2018

Linked content

This article is linked to Hwang et al and Genta papers. To view these articles visit https://doi.org/10.1111/apt.14424 and https://doi.org/10.1111/apt.14491.
Editorial: sofosbuvir plus daclatasvir for the treatment of hepatitis C—can one size fit all?
Authors: Sun J. , Liang X. , Fan R. , Hou J.
Published: February 2018

Linked content

This article is linked to El‐Khayat et al paper. To view this article visit https://doi.org/10.1111/apt.14482.
Evolution and development of scyphozoan jellyfish
Authors: Helm Rebecca R.
Published: February 2018

Scyphozoan jellyfish, or scyphomedusae, are conspicuous members of many ocean ecosystems, and have large impacts on human health and industry. Most scyphomedusae are the final stage in a complex life cycle that also includes two intermediate stages: the larval planula and benthic polyp. In species with all three life‐cycle stages, the metamorphosis of a polyp into a juvenile scyphomedusa (ephyra) is termed strobilation, and polyps can produce one ephyra (termed monodisc strobilation) or many ephyrae (termed polydisc strobilation). In contrast to species with planula, polyp and medusa stages, a handful of scyphozoan species possess modified life cycles with reduced or absent stages. The evolutionary patterns associated with strobilation and life‐cycle type have not been thoroughly investigated, and many studies of ephyra development and strobilation induction are not yet synthesized. Herein, I place the development of scyphomedusae in an evolutionary context. I first review the current evolutionary hypotheses for Scyphozoa. Next, I review what is known about scyphomedusa development across a broad diversity of species, including the first signs of strobilation, the formation of strobila segments, and the morphogenesis of ephyrae. I then review cases where the canonical scyphozoan life cycle has been modified, and take advantage of phylogenetic hypotheses to place these observations in an evolutionary context. I show that the evolution of monodisc strobilation occurred at least twice, and that the loss of intermediate life‐cycle stages occurred several times independently; by contrast, the reduction of the medusa stage appears to have occurred within a single clade. I then briefly review the major natural cues of strobilation induction. Finally, I summarize what is currently known about the molecular mechanisms of strobilation induction and ephyra development. I conclude with suggestions for future directions in the field.
The benefit sharing vision of H3Africa
Authors: Dauda Bege , Joffe Steven
Published: February 2018

One of the central ethical tenets of research in developing countries is the sponsor's obligation to benefit host participants and communities. Two known models of benefits provision dominate the ethical discourse of research in developing countries. The first model, known as the “reasonable availability,” endorses the obligation to provide interventions proven to be effective at the end of a study. This contrasts with the second model, known as “fair benefits,” which endorses other forms of benefits that host communities may deem as fair beyond those derived directly from the study's findings. This paper explores a third benefit model consistent with the writings of the Human Hereditary and Health in Africa (H3Africa) research initiative. The H3Africa—a North‐South collaborative initiative predicated by U.S. National Institutes of Health, the Wellcome Trust and the African Society of Human Genetics upholds a benefit model that endorses capacity building as the primary obligation of its research agenda. This is evident by the endorsement of mechanisms to strengthen capacity building in its research projects. While capacity building remains a plausible means of improving the expertise, quality and independence of research in Africa, sustainable measures are needed to realizing the full potential for African‐led research on the continent.
Layer‐specific global longitudinal strain reveals impaired cardiac function in patients with reversible ischemia
Authors: Hagemann Christoffer E. , Hoffmann Søren , Olsen Flemming J. , Jørgensen Peter G. , Fritz‐Hansen Thomas , Jensen Jan S. , Biering‐Sørensen Tor
Published: February 2018

Aims

Two‐dimensional speckle tracking echocardiography (2DSTE) detects early signs of left ventricular dysfunction; however, it is unknown whether layer‐specific global longitudinal strain (GLS) has incremental value in diagnosis of patients with reversible ischemia assessed by single photon emission computed tomography (SPECT).

Methods and Results

Eighty patients with stable angina pectoris (SAP), normal left ventricular ejection fraction (LVEF), and no history of ischemic heart disease were retrospectively identified to have been examined by 2DSTE, SPECT, and coronary angiography (CAG). Patients with a normal SPECT constituted the control group, and patients with a positive SPECT were divided into patients with or without (true‐ or false‐ positive SPECT) significant stenosis assessed by CAG. GLS was measured for two myocardial layers (endocardial and epicardial) and as well as mid‐myocardial GLS. Patients with reversible ischemia had significantly lower GLS compared to the control group (GLSEndocardial: −19.0 ± 4.4% vs −21.4 ± 3.7%, P = .011; GLSEpicardial: −14.3 ± 2.9% vs −16.3 ± 2.9%, P = .004); GLSMid‐myocardial: −16.5 ± 3.6% vs −18.6 ± 3.2%, P = .006. This difference was even more evident in patients with a true‐positive SPECT (GLSEndocardial: −18.0 ± 4.4% vs −21.4 ± 3.7%, P < .001; GLSEpicardial: −13.6 ± 3.0% vs −16.3 ± 2.9%, P < .001); GLSMid‐myocardial: −15.6 ± 3.6% vs −18.6 ± 3.2%, P < .001. Notably, no significant differences existed in patients with a false‐positive SPECT. GLSEpicardial was the only independent predictor of coronary artery disease.

In conclusion

In patients with SAP and preserved LVEF, layer‐specific GLS at rest identifies patients with reversible ischemia. This seems to be evident only in patients with a true‐positive SPECT, thus, 2DSTE at rest might improve the diagnostic accuracy of a positive SPECT.