bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-term Risk of a Seizure Disorder After Eclampsia
Authors: Nerenberg Kara A. , Park Alison L. , Vigod Simone N. , Saposnik Gustavo , Berger Howard , Hladunewich Michelle A. , Gandhi Shital , Silversides Candice K. , Ray Joel G.
Published: November 2017

OBJECTIVE:

To evaluate the incidence rate and relative risk of a seizure disorder after eclampsia.

METHODS:

We evaluated 1,565,733 births in a retrospective data linkage cohort study in Ontario, Canada, from April 1, 2002, to March 31, 2014. We included females aged 15–50 years and excluded patients with epilepsy, conditions predisposing to seizure, and those who died within 30 days of the delivery discharge date. The exposure was defined as a hypertensive disorder of pregnancy, namely 1) eclampsia, 2) preeclampsia, or 3) gestational hypertension. The referent was an unaffected pregnancy. The primary outcome was the risk of seizure disorder starting 31 days after a hospital birth discharge. Risk was expressed as an incidence rate and a hazard ratio (HR) with 95% CI. The predefined study hypothesis was that women with eclampsia would have an increased risk of future seizure disorder.

RESULTS:

There were 1,615 (0.10%) pregnancies exclusively affected by eclampsia, 17,264 (1.1%) with preeclampsia, 60,863 (3.9%) with gestational hypertension, and 1,485,991 (94.9%) unaffected. A future seizure disorder was significantly more likely after a pregnancy with eclampsia (4.58/10,000 person-years) than a pregnancy without a hypertensive disorder of pregnancy (0.72/10,000 person-years; crude HR 6.09, 95% CI 2.73–13.60). The adjusted HR was minimally attenuated from 6.09 to 5.42 (95% CI 2.42–12.12) after multivariable adjustment for confounders at the index birth as well as adjusting for traumatic brain injury, stroke, cerebral tumor, aneurysm or hemorrhage, and multiple sclerosis. The risk of seizure disorder was doubled in pregnancies affected by preeclampsia (adjusted HR 1.96, 95% CI 1.21–3.17), but not by gestational hypertension (adjusted HR 1.01, 95% CI 0.71–1.43).

CONCLUSION:

Women with eclampsia should be reassured that, although the relative risk of a seizure disorder is higher than unaffected women, the absolute risk is extremely low (approximately one seizure/2,200 person-years).
NOVEL CASE OF CLOSTRIDIUM PERFRINGENS ENDOPHTHALMITIS AFTER ANTI–VASCULAR ENDOTHELIAL GROWTH FACTOR INJECTION
Authors: Kadaba Varsha R. , Menon Jayshree
Published: November 2017

Introduction:

Endophthalmitis after anti–vascular endothelial growth factor injection is a rare complication but may lead to rapid destruction of structures within the eye. Infection with Clostridium perfringens has not previously been reported in this context.

Case Report:

A 90-year-old woman presented with endophthalmitis of the right eye, 2 days after an intravitreal injection of ranibizumab. Initial examination showed a high intraocular pressure, refractive to topical treatment, reduced vision, and a hypopyon. Gram stain showed a Gram-positive bacillus, which was identified as C. perfringens. Despite the use of intravitreal and intravenous antibiotics, the patient went on to develop cornea-scleral melt of the right eye. She required an evisceration on the fifth day after ranibizumab.

Conclusion:

This case describes a unique and virulent pathogen leading to globe loss after an anti–vascular endothelial growth factor injection. C. perfringens, naturally living in feces or soil, is more commonly associated with dirty traumatic open-globe injuries. However, it is an important pathogen to consider when there is rapid destruction of eye structures associated with endophthalmitis. Based on a root cause analysis of this case, our department has introduced patient information leaflets on hand hygiene to educate patients having intraocular injections.
PARANEOPLASTIC VITELLIFORM MACULOPATHY ASSOCIATED WITH METASTATIC MELANOMA
Authors: Rahimi Mansour , Navajas Eduardo V. , Sarraf David
Published: November 2017

Purpose:

To report a case of paraneoplastic vitelliform maculopathy in a patient with metastatic melanoma of unknown primary site.

Methods:

Case report. Main outcome measures include funduscopic examination, fluorescein angiography, fundus autofluorescence, and spectral domain optical coherence tomography.

Results:

A 44-year-old man with a known history of metastatic melanoma was referred for ophthalmic evaluation because of bilateral vision loss. Funduscopic examination was remarkable for vitelliform maculopathy that was confirmed with fundus autofluorescence and spectral domain optical coherence tomography.

Conclusion:

We describe a rare case of paraneoplastic vitelliform maculopathy. There are many etiologies of acquired vitelliform retinal lesions in the retina. Multimodal retinal imaging, including fundus autofluorescence and spectral domain optical coherence tomography, can be best used to identify these lesions. A history of systemic metastatic melanoma should be ruled out in patients with vitelliform maculopathy.
AUTOIMMUNE RETINOPATHY IN A PATIENT WITH A MISSENSE MUTATION IN PITPNM3
Authors: Bakhoum Mathieu F. , Sengillo Jesse D. , Cui Xuan , Tsang Stephen H.
Published: November 2017

Purpose:

To describe a patient with a PITPNM3 missense mutation who developed late-onset autoimmune retinopathy.

Methods:

Case report.

Results:

An 85-year-old man presented with decreased vision, nyctalopia, and photoaversion after an uncomplicated cataract surgery. Multimodal retinal imaging revealed a scalloped pattern of atrophy and a ring of hyperautofluorescence in the perifoveal area on fundus autofluorescence. Spectral domain optical coherence tomography demonstrated loss of the ellipsoid band, along with outer retinal atrophy, sparing the fovea in both eyes. Full field electroretinogram revealed extinguished rod response and severely attenuated cone response. Antiretinal antibodies to 20-kDa and 125-kDa proteins were detected. Whole-exome sequencing revealed a heterozygous variant, c.2579T>C, p.(Ile860Thr) in PITPNM3, predicted to be severely damaging and deleterious to the protein structure and function. Over the course of 3 months, the patient experienced a rapid progression. Neoplastic workup was negative and he was started on immunosuppressive therapy for a presumed diagnosis of nonparaneoplastic autoimmune retinopathy.

Conclusion:

To the authors' knowledge, this is the first report of autoimmune retinopathy in a patient with PITPNM3 mutation. PITPNM3 has been previously shown to affect regulatory T cell function.
CAT SCRATCH DISEASE IMITATING A TOXOCARA GRANULOMA OF THE OPTIC DISK
Authors: Sayyad Fouad E. , Zeglam Ahmaida , Agarwal-Sinha Swati
Published: November 2017

Purpose:

The study reports an unusual presentation of a young female patient presenting with a granulomatous posterior pole mass and profound vision loss secondary to infection with Bartonella henselae.

Methods:

A single case report in a child.

Results:

An 8-year-old female presented with a recent history of flu-like illness associated with profound vision loss, panuveitis and leukocoria in the left eye. She was found to have a posterior granulomatous mass associated with an exudative retinal detachment presumed as a toxocara granuloma. Magnetic Resonance Imaging ruled out retinoblastoma. Lab work done was negative for toxocariasis and positive for Bartonella henselae titers. She was treated for Cat Scratch Disease (CSD) with steroids and azithromycin. With treatment, the inflammation and exudative retinal detachment resolved, however, the patient had no improvement in visual acuity.

Conclusions:

Young patients presenting with leukocoria need a full work up, which includes ruling out retinoblastoma. CSD can present as a granulomatous mass similar to toxocariasis, which can rarely lead to debilitating and irreversible vision loss.
Vitamin B1 Deficiency Related to Excessive Soft Drink Consumption in Japan
Authors: Okumura Akihisa , Ida Shinobu , Mori Masaaki , Shimizu Toshiaki ,   Committee on Pediatric Nutrition of the Child Health Consortium of Japan
Published: November 2017

The aim of this study was to clarify the picture of vitamin B1 deficiency (VB1D) caused by excessive soft drink consumption in Japan. A nationwide survey of children with soft drink‐induced VB1D was conducted using a structured research form. Patient information was obtained from 2 sources: training hospitals for board‐certified pediatricians and those identified by a database search. We obtained data from 33 children. Twenty‐one children had a nonnurturing home environment. The median duration of excessive soft drink intake was 3.5 months and the daily intake was 1000 mL or more in 25 children. Infection was the most common reason for excessive soft drink consumption. Only 4 children had the classical triad of Wernicke encephalopathy. One child died, and 12 had neurological sequelae. A majority of children with soft drink‐induced VB1D did not have a nurturing home environment. It is imperative to establish measures to prevent future cases of VB1D.
Noninvasive Methods of Predicting Large Esophageal Varices in Children With Intrahepatic Portal Hypertension
Authors: Adami Marina Rossato , Kieling Carlos Oscar , Schwengber Fernando Pereira , Hirakata Vania N. , Vieira Sandra Maria Gonçalves
Published: November 2017

Objective:

Esophageal variceal bleeding is a severe complication of portal hypertension. The standard diagnostic screening test and therapeutic procedure for esophageal varices (EV) is endoscopy, which is invasive in pediatric patients. This study aimed to evaluate the role of noninvasive parameters as predictors of large varices in children with intrahepatic portal hypertension.

Methods:

Participants included in this cross‐sectional study underwent a screening endoscopy. Variceal size, red marks, and portal gastropathy were assessed and rated. Patients were classified into two groups: Group 1 (G1) with small or no varices and Group 2 (G2) with large varices. The population consisted of 98 children with no history of gastrointestinal (GI) bleeding, with a mean age of 8.9 ± 4.7 years. The main outcome evaluated was the presence of large varices.

Results:

The first endoscopy session revealed the presence of large varices in 32 children. The best noninvasive predictors for large varices were platelets (Area under the ROC Curve [AUROC] 0.67; 95% CI 0.57–0.78), the Clinical Prediction Rule (CPR; AUROC 0.65; 95% CI 0.54–0.76), and risk score (AUROC 0.66; 95% CI 0.56–0.76). The logistic regression model showed that children with a CPR value under 114 were 8.59 times more likely to have large varices. Risk scores higher than −1.2 also increased the likelihood of large varices (OR 6.09; P = 0.014), as did a platelet count/spleen size z score lower than 25 (OR 3.99; P = 0.043). The combination of these three tests showed a high negative predictive value.

Conclusions:

The CPR, the risk score, and the platelet count/spleen size z score could be helpful in identifying cirrhotic children who may be eligible for endoscopy.
Emergency Intubations in a High-Volume Pediatric Emergency Department
Authors: Pek Jen Heng , Ong Gene Yong-Kwang
Published: November 2017

Introduction

Resuscitation of critically ill children can be chaotic, and emergency airway management is often fraught with difficulties. This study aimed to characterize the Singaporean landscape of tracheal intubation in a pediatric emergency unit, placing emphasis on safety outcomes, procedural process of care, and provider training.

Methods

A retrospective review of all cases presented to the KK Women's and Children's Hospital from January 2009 to December 2013 with intubation carried out within the pediatric emergency unit was done. Medical records were accessed for data collection, and the information was subsequently used for analysis.

Results

A total of 207 intubations were carried out in the pediatric emergency unit. The median age was 4 years (interquartile range, 11 months to 8 years). Oral tracheal intubation with the combination of sedation and paralysis was the main approach. Atropine was used for pretreatment in 156 cases (75.4%). Midazolam was the most commonly used induction agent, and succinylcholine was the most commonly used the paralytic agent. Intubation was achieved on the first attempt in 175 cases (84.5%). Postintubation sedation was initiated in 94 cases (45.4%). Postintubation paralysis was initiated in 50 cases (24.2%). Postintubation analgesia was initiated in 13 cases (6.3%). Twenty emergency intubations (9.7%) were associated with at least 1 tracheal intubation adverse event, with 7 cases (3.4%) having severe tracheal intubation adverse events. In 1 case (0.5%), the patient died within the pediatric emergency unit, and 27 patients (13.0%) did not survive to discharge from the hospital.

Conclusions

All tracheal intubations performed were successful. Variance still exists in tracheal intubation practice. Further elucidation of patient, practice, and provider factors will aid development of a bundle quality improvement intervention directed at addressing these factors.
Important Considerations for Performing Prepectoral Breast Reconstruction
Authors: Sbitany Hani
Published: November 2017

Prepectoral breast reconstruction has emerged as an excellent technique for postmastectomy reconstruction, as it allows for full preservation of a patient’s pectoralis major muscle and chest wall function. This reduces pain, eliminates animation deformity, and results in high patient satisfaction. Safely performed prepectoral breast reconstruction requires a careful patient selection process before committing to the procedure, taking into account comorbidities, radiation status, and oncologic criteria such as tumor location and breast cancer stage. Furthermore, a thorough intraoperative assessment of mastectomy skin flaps is critical, with careful and precise confirmation that the skin is viable and well perfused, prior to proceeding with prepectoral breast reconstruction. This can be done both clinically and with perfusion assessment devices. The use of acellular dermal matrix (ADM) has enhanced outcomes and aesthetics of prepectoral reconstruction, by providing implant coverage and soft-tissue support. The ADM also adds the benefit of reducing capsular contracture rates and offers full control over the aesthetic definition of the newly reconstructed breast pocket. Aesthetic enhancement of results requires routine use of oversizing implants in the skin envelope, careful selection of full capacity or cohesive gel implants, and autologous fat grafting. In this way, patients in all clinical scenarios can benefit from the full muscle-sparing technique of prepectoral breast reconstruction, including those undergoing immediate reconstruction, delayed reconstruction, and delayed conversion from a subpectoral to prepectoral plane to correct animation deformity.
Options in Acellular Dermal Matrix–Device Assembly
Authors: Sigalove Steven
Published: November 2017

Prepectoral prosthetic breast reconstruction has become increasingly popular during the last several years. Original shortcomings and poor outcomes in the 1970s have been overcome with the use of the bioengineered breast concept—namely, use of improved form stable breast implants, autologous fat grafting, and acellular dermal matrices (ADMs). Careful use of these reconstructive tools combined with improved mastectomy skin flaps has lead to successful early outcomes. Prepectoral breast reconstruction mitigates the animation deformities and muscle tightness previously associated with dual-plane prosthetic breast reconstruction while at the same time producing reproducible and outstanding aesthetic outcomes. The use of ADM is a critical component to performing prepectoral breast reconstruction. There are many techniques utilized to inset the ADM. Various methods of direct in vivo inset have been performed. These techniques are employed following completion of the mastectomy and are performed with both 2-stage as well as single-stage direct-to-implant reconstruction. Various ex vivo techniques have also been used for prepectoral breast reconstruction. Various prefabricated constructs of ADM and implant/tissue expander can be created on the back table while the mastectomy is in progress, which decreases operative time and improves surgical efficiency. This article will describe briefly the history of prepectoral reconstruction as well as describing the various techniques used for creating the ADM-device interphase.
Prepectoral Breast Reconstruction: The Breast Surgeon’s Perspective
Authors: Storm-Dickerson Toni , Sigalove Noemi
Published: November 2017

Prepectoral breast reconstruction has been reemerging as a technique for postmastectomy implant-based reconstruction. Due to its advantage in eliminating animation deformity, shortening length of hospital stay and decreasing the amount of narcotics used for pain control, the technique has been embraced by patients and surgeons alike. The authors examined the breast surgeon’s perspective regarding prepectoral reconstruction taking into consideration oncologic criteria, breast cancer recurrence, surgical technique, and the team approach to patient care.
Pharmacokinetics and pharmacodynamics of antibiotics in central nervous system infections
Authors: Nau Roland , Seele Jana , Djukic Marija , Eiffert Helmut
Published: November 2017

Purpose of review

The barriers surrounding the central nervous system (CNS) together with the emergence of multiresistant pathogens pose a therapeutic challenge for the effective treatment of CNS infections.

Recent findings

In addition to vancomycin, colistin and aminoglycosides, classically used for intrathecal injection, drug concentrations in cerebrospinal fluid after intrathecal injection of daptomycin and tigecyclin were recently studied.

The entry of antiinfectives into the CNS compartments is determined by the physicochemical properties of the drug and by conditions in the host. The most important drug properties are lipophilicity at a neutral pH, molecular mass and drug binding to serum proteins. In clinical practice, active transport is of importance only for some drugs. In recent years, intrathecal injection of antiinfectives in addition to systemic therapy has regained attention as a means to achieve high cerebrospinal fluid concentrations. The classification of antibacterials and antifungals into time-dependent and concentration-dependent compounds is also valid for the CNS compartments.
18F-FDG PET/CT Imaging of Hidradenocarcinoma Arising From Preexisting Hidradenoma of the Knee
Authors: Patel Tirth V. , Oldan Jorge
Published: November 2017

Malignant tumors of the sweat glands are exceedingly rare and aggressive tumors. We present here a case of a 60-year-old man with a malignant hidradenocarcinoma that developed in a background of preexisting benign hidradenoma on the lateral aspect of the knee that was initially resected, but rapidly recurred with associated inguinal lymphadenopathy. 18F-FDG PET/CT was performed as part of preoperative staging, which demonstrated abnormal inguinal lymph nodes and metastatic disease to the lungs. FDG PET/CT can play an invaluable role in the initial staging and follow-up of this rare malignancy.
Incisional Hernia After Midline Versus Transverse Specimen Extraction Incision
Authors: Lee Lawrence , Mata Juan , Droeser Raoul A. , Kaneva Pepa , Liberman Sender , Charlebois Patrick , Stein Barry , Fried Gerald M. , Feldman Liane S.
Published: November 2017

Objective:

To compare the incidence of incisional hernia (IH) between midline and transverse specimen extraction site in patients undergoing laparoscopic colectomy.

Background:

Midline specimen extraction incision is most commonly used in laparoscopic colectomy, but has high IH risk. IH may be lower for transverse incision.

Methods:

A single-center superiority trial was conducted. Eligible patients undergoing laparoscopic colectomy were randomly assigned to midline or transverse specimen extraction. Primary outcome was IH incidence at 1 year. Power calculation required 76 patients per group to detect a reduction in IH from 20% to 5%. Secondary outcomes included perioperative outcomes, pain scores, health-related quality of life (SF-36), and cosmesis (Body Image Questionnaire).

Results:

A total of 165 patients were randomly assigned to transverse (n = 79) or midline (n = 86) specimen extraction site, of which 141 completed 1-year follow-up (68 transverse, 73 midline). Patient, tumor, surgical data, and perioperative morbidity were similar. Pain scores were similar on each postoperative day. On intention-to-treat analysis, there was no difference in the incidence of IH at 1 year (transverse 2% vs midline 8%, P = 0.065) or after mean 30.3 month (standard deviation 9.4) follow-up (6% vs 14%, P = 0.121). On per-protocol analysis there were more IH after midline incision with longer follow-up (15% vs 2%, P = 0.013). On intention-to-treat analysis, SF-36 domains body pain and social functioning were improved after transverse incision. Cosmesis was higher after midline incision on per-protocol analysis, but without affecting body image.

Conclusions:

Per-protocol analysis of this trial demonstrates that a transverse specimen extraction site has a lower incidence of IH compared to midline with longer follow-up but has worse cosmesis.
Cerebrovascular Steal Phenomenon and Electroconvulsive Therapy
Authors: Hategan Ana , Hirsch Calvin H.
Published: November 2017

Electroconvulsive therapy (ECT) is a safe and effective treatment for major depressive disorder, but cerebrovascular and cardiovascular complications, although rare, remain the most concerning. This is particularly notable in those with preexisting cerebrovascular disease, which impacts dynamic cerebral autoregulation. In these patients, the increased blood flow to the seizing portions of the brain induced by ECT potentially can reduce cerebral blood flow to ischemic areas, possibly causing adverse neurological events. The authors describe a patient with chronic cerebral ischemic disease, chronic anemia, and major depressive disorder undergoing ECT to achieve remission. The patient developed recurrent focal neurological deficits after each ECT procedure, with neurological recovery within 48 hours post-ECT. Clinical guidelines may need to be updated for the management of ECT patients with cerebrovascular disease who may be at an increased risk of intraictal and possibly postictal regional ischemia, especially in areas already compromised by a prior stroke and/or by reduced cerebral oxygenation caused by symptomatic anemia at risk of ischemia. Research is needed to assess changes in regional cerebral blood flow during and after ECT in patients with cerebrovascular disease, including small-vessel cerebral ischemia, and to evaluate these changes in relation to the location, intensity, and duration of induced seizure.
Visualizing the complex functions and mechanisms of the anaphase promoting complex/cyclosome (APC/C)
Authors: Alfieri Claudio , Zhang Suyang , Barford David
Published: November 2017

The anaphase promoting complex or cyclosome (APC/C) is a large multi-subunit E3 ubiquitin ligase that orchestrates cell cycle progression by mediating the degradation of important cell cycle regulators. During the two decades since its discovery, much has been learnt concerning its role in recognizing and ubiquitinating specific proteins in a cell-cycle-dependent manner, the mechanisms governing substrate specificity, the catalytic process of assembling polyubiquitin chains on its target proteins, and its regulation by phosphorylation and the spindle assembly checkpoint. The past few years have witnessed significant progress in understanding the quantitative mechanisms underlying these varied APC/C functions. This review integrates the overall functions and properties of the APC/C with mechanistic insights gained from recent cryo-electron microscopy (cryo-EM) studies of reconstituted human APC/C complexes.
The first cell-fate decision of mouse preimplantation embryo development: integrating cell position and polarity
Authors: Mihajlović Aleksandar I. , Bruce Alexander W.
Published: November 2017

During the first cell-fate decision of mouse preimplantation embryo development, a population of outer-residing polar cells is segregated from a second population of inner apolar cells to form two distinct cell lineages: the trophectoderm and the inner cell mass (ICM), respectively. Historically, two models have been proposed to explain how the initial differences between these two cell populations originate and ultimately define them as the two stated early blastocyst stage cell lineages. The ‘positional’ model proposes that cells acquire distinct fates based on differences in their relative position within the developing embryo, while the ‘polarity’ model proposes that the differences driving the lineage segregation arise as a consequence of the differential inheritance of factors, which exhibit polarized subcellular localizations, upon asymmetric cell divisions. Although these two models have traditionally been considered separately, a growing body of evidence, collected over recent years, suggests the existence of a large degree of compatibility. Accordingly, the main aim of this review is to summarize the major historical and more contemporarily identified events that define the first cell-fate decision and to place them in the context of both the originally proposed positional and polarity models, thus highlighting their functional complementarity in describing distinct aspects of the developmental programme underpinning the first cell-fate decision in mouse embryogenesis.
Fluid flow in porous media using image-based modelling to parametrize Richards' equation
Authors: Cooper L. J. , Daly K. R. , Hallett P. D. , Naveed M. , Koebernick N. , Bengough A. G. , George T. S. , Roose T.
Published: November 2017

The parameters in Richards' equation are usually calculated from experimentally measured values of the soil–water characteristic curve and saturated hydraulic conductivity. The complex pore structures that often occur in porous media complicate such parametrization due to hysteresis between wetting and drying and the effects of tortuosity. Rather than estimate the parameters in Richards' equation from these indirect measurements, image-based modelling is used to investigate the relationship between the pore structure and the parameters. A three-dimensional, X-ray computed tomography image stack of a soil sample with voxel resolution of 6 μm has been used to create a computational mesh. The Cahn–Hilliard–Stokes equations for two-fluid flow, in this case water and air, were applied to this mesh and solved using the finite-element method in COMSOL Multiphysics. The upscaled parameters in Richards' equation are then obtained via homogenization. The effect on the soil–water retention curve due to three different contact angles, 0°, 20° and 60°, was also investigated. The results show that the pore structure affects the properties of the flow on the large scale, and different contact angles can change the parameters for Richards' equation.
Theory of energy harvesting from heartbeat including the effects of pleural cavity and respiration
Authors: Zhang Yangyang , Lu Bingwei , Lü Chaofeng , Feng Xue
Published: November 2017

Self-powered implantable devices with flexible energy harvesters are of significant interest due to their potential to solve the problem of limited battery life and surgical replacement. The flexible electronic devices made of piezoelectric materials have been employed to harvest energy from the motion of biological organs. Experimental measurements show that the output voltage of the device mounted on porcine left ventricle in chest closed environment decreases significantly compared to the case of chest open. A restricted-space deformation model is proposed to predict the impeding effect of pleural cavity, surrounding tissues, as well as respiration on the efficiency of energy harvesting from heartbeat using flexible piezoelectric devices. The analytical solution is verified by comparing theoretical predictions to experimental measurements. A simple scaling law is established to analyse the intrinsic correlations between the normalized output power and the combined system parameters, i.e. the normalized permitted space and normalized electrical load. The results may provide guidelines for optimization of
in vivo
energy harvesting from heartbeat or the motions of other biological organs using flexible piezoelectric energy harvesters.
How fish eggs are preadapted for the evolution of matrotrophy
Authors: Morrison Keenan R. , Ngo Vyvian , Cardullo Richard A. , Reznick David N.
Published: November 2017

Teleost fishes evolved livebearing via egg retention 14 times. Matrotrophy has evolved within 12 of those lineages. By contrast, squamate reptiles evolved livebearing over 115 times, but only two to four of those lineages are known to have evolved matrotrophy. Is the discrepancy between these organisms in the probability of this transition caused by differences in their eggs? We show that the eggs of oviparous species in the superorder Atherinomorpha can acquire small organic molecules from their surrounding environment against a concentration gradient via mechanisms of active transport. Uptake rates were inhibited by competing radiolabelled amino acids against unlabelled versions of themselves. Transport was non-specific as uptake rates were similar for
l
-leucine and its biologically uncommon enantiomer
d
-leucine. Eggs are also capable of transporting larger microspheres across the membrane, but transport is inhibited at temperatures below 4°C, suggesting active transport occurs via pinocytosis. Conflict theory predicts that the ability of the egg to acquire maternal resources will facilitate the embryo–parent arms race that leads to the evolution of matrotrophy following the transition to livebearing. The shelled eggs of amniotes lack such access to maternal resources when retained in the evolution of viviparity.
The effect of climate change on the duration of avian breeding seasons: a meta-analysis
Authors: Halupka Lucyna , Halupka Konrad
Published: November 2017

Many bird species are advancing the timing of their egg-laying in response to a warming climate. Little is known, however, of whether this advancement affects the respective length of the breeding seasons. A meta-analysis of 65 long-term studies of 54 species from the Northern Hemisphere has revealed that within the last 45 years an average population has lengthened the season by 1.4 days per decade, which was independent from changes in mean laying dates. Multi-brooded birds have prolonged their seasons by 4 days per decade, while single-brooded have shortened by 2 days. Changes in season lengths covaried with local climate changes: warming was correlated with prolonged seasons in multi-brooded species, but not in single-brooders. This might be a result of higher ecological flexibility of multi-brooded birds, whereas single brooders may have problems with synchronizing their reproduction with the peak of food resources. Sedentary species and short-distance migrants prolonged their breeding seasons more than long-distance migrants, which probably cannot track conditions at their breeding grounds. We conclude that as long as climate warming continues without major changes in ecological conditions, multi-brooded or sedentary species will probably increase their reproductive output, while the opposite effect may occur in single-brooded or migratory birds.
Food-web dynamics under climate change
Authors: Zhang Lai , Takahashi Daisuke , Hartvig Martin , Andersen Ken H.
Published: November 2017

Climate change affects ecological communities through its impact on the physiological performance of individuals. However, the population dynamic of species well inside their thermal niche is also determined by competitors, prey and predators, in addition to being influenced by temperature changes. We use a trait-based food-web model to examine how the interplay between the direct physiological effects from temperature and the indirect effects due to changing interactions between populations shapes the ecological consequences of climate change for populations and for entire communities. Our simulations illustrate how isolated communities deteriorate as populations go extinct when the environment moves outside the species' thermal niches. High-trophic-level species are most vulnerable, while the ecosystem function of lower trophic levels is less impacted. Open communities can compensate for the loss of ecosystem function by invasions of new species. Individual populations show complex responses largely uncorrelated with the direct impact of temperature change on physiology. Such complex responses are particularly evident during extinction and invasion events of other species, where climatically well-adapted species may be brought to extinction by the changed food-web topology. Our results highlight that the impact of climate change on specific populations is largely unpredictable, and apparently well-adapted species may be severely impacted.
Long-term archives reveal shifting extinction selectivity in China's postglacial mammal fauna
Authors: Turvey Samuel T. , Crees Jennifer J. , Li Zhipeng , Bielby Jon , Yuan Jing
Published: November 2017

Ecosystems have been modified by human activities for millennia, and insights about ecology and extinction risk based only on recent data are likely to be both incomplete and biased. We synthesize multiple long-term archives (over 250 archaeological and palaeontological sites dating from the early Holocene to the Ming Dynasty and over 4400 historical records) to reconstruct the spatio-temporal dynamics of Holocene–modern range change across China, a megadiverse country experiencing extensive current-day biodiversity loss, for 34 mammal species over three successive postglacial time intervals. Our combined zooarchaeological, palaeontological, historical and current-day datasets reveal that both phylogenetic and spatial patterns of extinction selectivity have varied through time in China, probably in response both to cumulative anthropogenic impacts (an ‘extinction filter’ associated with vulnerable species and accessible landscapes being affected earlier by human activities) and also to quantitative and qualitative changes in regional pressures. China has experienced few postglacial global species-level mammal extinctions, and most species retain over 50% of their maximum estimated Holocene range despite millennia of increasing regional human pressures, suggesting that the potential still exists for successful species conservation and ecosystem restoration. Data from long-term archives also demonstrate that herbivores have experienced more historical extinctions in China, and carnivores have until recently displayed greater resilience. Accurate assessment of patterns of biodiversity loss and the likely predictive power of current-day correlates of faunal vulnerability and resilience is dependent upon novel perspectives provided by long-term archives.
Functional analysis of the EsaB component of the Staphylococcus aureus Type VII secretion system
Authors: Casabona M. Guillermina , Buchanan Grant , Zoltner Martin , Harkins Catriona P. , Holden Matthew T. G. , Palmer Tracy
Published: November 2017

Type VII secretion systems (T7SS) are found in many bacteria and secrete proteins involved in virulence and bacterial competition. In Staphylococcus aureus the small ubiquitin-like EsaB protein has been previously implicated as having a regulatory role in the production of the EsxC substrate. Here we show that in the S. aureus RN6390 strain, EsaB does not genetically regulate production of any T7 substrates or components, but is indispensable for secretion activity. Consistent with EsaB being an essential component of the T7SS, loss of either EsaB or EssC are associated with upregulation of a common set of iron acquisition genes. However, a further subset of genes were dysregulated only in the absence of EsaB. Quantitative western blotting indicates that EsaB is present at very low levels in cells. Substitution of a highly conserved threonine for alanine or arginine resulted in a loss of EsaB activity and destabilisation of the protein. Taken together our findings show that EsaB is essential for T7SS activity in RN6390.
A standardized technique for high-pressure cooling of protein crystals
Authors: Quirnheim Pais David , Rathmann Barbara , Koepke Juergen , Tomova Cveta , Wurzinger Paul , Thielmann Yvonne
Published: November 2017

Cryogenic temperatures slow down secondary radiation damage during data collection from macromolecular crystals. In 1973, cooling at high pressure was identified as a method for cryopreserving crystals in their mother liquor [Thomaneket al.(1973).Acta Cryst.A29, 263–265]. Results from different groups studying different crystal systems indicated that the approach had merit, although difficulties in making the process work have limited its widespread use. Therefore, a simplified and reliable technique has been developed termed high-pressure cooling (HPC). An essential requirement for HPC is to protect crystals in capillaries. These capillaries form part of new sample holders with SPINE standard dimensions. Crystals are harvested with the capillary, cooled at high pressure (220 MPa) and stored in a cryovial. This system also allows the usage of the standard automation at the synchrotron. Crystals of hen egg-white lysozyme and concanavalin A have been successfully cryopreserved and yielded data sets to resolutions of 1.45 and 1.35 Å, respectively. Extensive work has been performed to define the useful working range of HPC in capillaries with 250 µm inner diameter. Three different 96-well crystallization screens that are most frequently used in our crystallization facility were chosen to study the formation of amorphous ice in this cooling setup. More than 89% of the screening solutions were directly suitable for HPC. This achievement represents a drastic improvement for crystals that suffered from cryoprotection or were not previously eligible for cryoprotection.
Approaches toab initiomolecular replacement of α-helical transmembrane proteins
Authors: Thomas Jens M. H. , Simkovic Felix , Keegan Ronan , Mayans Olga , Zhang Chengxin , Zhang Yang , Rigden Daniel J.
Published: November 2017

α-Helical transmembrane proteins are a ubiquitous and important class of proteins, but present difficulties for crystallographic structure solution. Here, the effectiveness of theAMPLEmolecular replacement pipeline in solving α-helical transmembrane-protein structures is assessed using a small library of eight ideal helices, as well as search models derived fromab initiomodels generated both with and without evolutionary contact information. The ideal helices prove to be surprisingly effective at solving higher resolution structures, butab initio-derived search models are able to solve structures that could not be solved with the ideal helices. The addition of evolutionary contact information results in a marked improvement in the modelling and makes additional solutions possible.
Adaptive organizational leadership style
Authors: Yaghi Abdulfattah
Published: November 2017

Purpose

The purpose of this paper is to examine organizational leadership in a traditional, non-western country where citizens’ happiness drives the practices of the public administration managers.

Design/methodology/approach

This study uses the Multifactor Leadership Questionnaire (MLQ) to examine leadership in a traditional, non-western country where organizational change dominates the public sector. Triangulation of quantitative and qualitative research methods is used.

Findings

Triangulation of quantitative and qualitative research methods reveals that the way managers respond to organizational change leads to utilizing an adaptive leadership style; a mixture of dynamic and rigid practices. Organizational change creates peculiar circumstances that make it thus imperative for managers to mix transformational and transactional practices in order to not only survive, but also excel. While some of the findings conform to those of previous studies, they indicate that the MLQ does not seem to adequately reflect the impact of organizational change on leadership. The study also provides evidence that adaptive leadership is driven by cultural and organizational necessities.

Research limitations/implications

The limitations of the study can be avoided in future research. In particular, the number of interviews has limited the ability to better reflect all dimensions of the adaptive leadership style. Due to time and resource availability, the inability to focus more on the individual level of the cultural factor and its impact on leadership style may have limited the scope of the analysis. Finally, the present study did not examine the cultural variations within the United Arab Emirates universal culture especially in relationship with region, age group, and gender of the managers.

Originality/value

The paper examines leadership in the Middle East context where rare studies in leadership have been conducted. The study also examines the usability of MLQ in Arab context where organizational change persists.
Assessment of food security among households in Eastern Cape Province, South Africa
Authors: Megbowon Ebenezer Toyin , Mushunje Abbyssinia
Published: November 2017

Purpose

The purpose of this paper is to analyze food security status and its determinants among households in the Eastern Cape Province of South Africa.

Design/methodology/approach

The analysis is based on the General Household Survey which was conducted in 2014 where 3,033 households were sampled from the province. Specifically, this study examines the determinants of food security proxy by dietary diversity (24-hour recall) using descriptive statistics, Poisson regression. A frequency count of food groups consumed household dietary diversity score was used as the explained variable.

Findings

The descriptive analysis shows that, although 61.7 percent of households in the study area have a high dietary diversity score, however, food group giving micronutrients are less consumed as food groups having cereals (maize), beef, sugar and oil was mostly consumed. Results on the marginal effect of Poisson regression indicate that household head characteristics (age, gender, education, marital status, and employment status), pension receiving households and geographical location significantly influence household dietary diversity.

Originality/value

This study advocates for the intensification of rural development and food security programs, formal and informal education for household heads, female empowerment and dietary enlightenment for households in order to promote the consumption of diverse diets and more healthful food groups.
Country-level macro-corporate governance and the outward foreign direct investment
Authors: Tong Tong , Singh Tarlok , Li Bin
Published: November 2017

Purpose

China’s outward foreign direct investment (ODI) has become a recent phenomenon in that China is now rated as the world’s third largest country for ODI. Previous studies have found that China’s ODI is driven by the attractions of natural resources and overseas markets. Yet these studies have ignored the role of corporate governance at a national level, the paper aims to discuss these issues.

Design/methodology/approach

The Kaufmann et al. (1999) data set is used in our study and the data sample have covered the period from 2003 to 2012 for a comprehensive set of 171 host countries. Random effects model are applied in the paper and population average model is used to check the robustness of the results.

Findings

The authors find that the effects of macro-corporate governance are distinct in different sample periods, as well as in geographical and economic regions, when attracting China’s ODI. Indicators such as political stability, the absence of violence, regulatory effectiveness, regulatory quality, the rule of law and the control of corruption are found to be positively related to China’s ODI.

Originality/value

This is one of the first papers to investigate the relationship between macro-corporate governance indicators and China’s ODI. 171 countries are included in the data sample and sub-sample tests are also conducted.
Waqf, Sustainable Development Goals (SDGs) and maqasid al-shariah
Authors: Abdullah Mohammad
Published: November 2017

Purpose

This paper attempts to contextualise the potential role of waqf (plural; awqaf, Islamic perpetual trust) in the contemporary world, particularly, in the developmental arena. The purpose of this paper is to provide a framework for awqaf to maintain its convergence with some of the fundamental goals of the SDGs which are also congruent with the maqasid al-shariah (the higher objectives of shariah).

Design/methodology/approach

This paper is based on a desk-based research, and it adopts the qualitative research paradigm for the analysis of the available literature.

Findings

This paper finds that most of the 17 developmental goals of the SDGs comfortably match with the long-term objectives of shariah and there is good scope for the stakeholders of awqaf to develop waqf-based development plan in line with the framework of SDGs. Additionally, it finds that the global awqaf enjoy sufficient financial capacity to help muslim majority countries to realise some of the most relevant and urgent maqasid-oriented SDGs in a timely manner.

Research limitations/implications

The scope of this paper is limited to analyse the potential role of global awqaf in realising some of the most urgent maqasid-based development objectives in congruence with SDGs. For the purpose of maintaining the coherence in the focus of the study, this paper does not undertake any comparison between the waqf and other forms of endowments/charities in fulfilling the similar objectives.

Practical implications

This paper provides a framework for maqasid-oriented waqf-based development plan followed by provision of some critical recommendations on how the global awqaf can potentially spearhead the initiative of Islamic charities in realising the maqasid-oriented SDGs among muslim majority countries.

Originality/value

This paper adds original value to the available literature on the potential of waqf in the arena of development. The paper analyses the role of waqf in achieving the most urgent maqasid-based SDGs, and thus, it fills the existing gap of a systematic research on the possible collaboration of global awqaf and SDGs.