bluuebunny/crossref_metadata_2025 huggingface dataset:
Higher Sun Exposure is Associated With Lower Risk of Pediatric Inflammatory Bowel Disease
Authors: Holmes Elizabeth Ann , Ponsonby Anne‐Louise , Pezic Angela , Ellis Justine A. , Kirkwood Carl D. ,   PAID consortium, Lucas Robyn M.
Published: May 2019

Objectives:

The incidence of pediatric inflammatory bowel disease (IBD) is increasing worldwide. Ecological studies show higher incidence in regions at higher latitude or lower ambient ultraviolet radiation; individual‐level associations with sun exposure have not been assessed.

Methods:

We recruited children (0–17 years) with IBD from 2 large hospitals in Melbourne, Australia. Control participants were recruited from the day surgery unit of one of the same hospitals. Questionnaires provided data on demographics, past sun exposure, the likelihood of sunburn (skin sensitivity) or tanning following sun exposure, use of sun protection, physical activity, and parental smoking and education. Grandparent ancestry was used to determine participant ethnicity. Cases and controls were matched on age and sex. We used conditional logistic regression to test the association between being an IBD case and past sun exposure at different ages, adjusted for a range of other factors.

Results:

After matching, n = 99 cases and n = 396 controls were included in the analysis. In multivariable analysis, for each 10 min increment in leisure‐time sun exposure in summer or winter there was a linear 6% reduction in the odds of having IBD (P = 0.002). Results were similar in sensitivity analyses including only the most recently diagnosed cases, only Caucasian cases and controls, only those with symptom onset within the year before study entry, or additionally adjusted for age or physical activity.

Conclusions:

Higher sun exposure in the previous summer or winter was associated with a reduced risk of having IBD. There are plausible pathways that could mediate this effect.
Feeding the Late and Moderately Preterm Infant
Authors:   ESPGHAN Committee on Nutrition, Lapillonne Alexandre , Bronsky Jiri , Campoy Cristina , Embleton Nicholas , Fewtrell Mary , Fidler Mis Nataša , Gerasimidis Konstantinos , Hojsak Iva , Hulst Jessie , Indrio Flavia , Molgaard Christian , Moltu Sissel Jennifer , Verduci Elvira , Domellöf Magnus
Published: May 2019

Nutritional guidelines and requirements for late or moderately preterm (LMPT) infants are notably absent, although they represent the largest population of preterm infants. The European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) Committee on Nutrition (CoN) performed a review of the literature with the aim to provide guidance on how to feed infants born LMPT, and identify gaps in the literature and research priorities.

Only limited data from controlled trials are available. Late preterm infants have unique, often unrecognized, vulnerabilities that predispose them to high rates of nutritionally related morbidity and hospital readmissions. They frequently have feeding difficulties that delay hospital discharge, and poorer rates of breastfeeding initiation and duration compared with term infants. This review also identified that moderately preterm infants frequently exhibit postnatal growth restriction.

The ESPGHAN CoN strongly endorses breast milk as the preferred method of feeding LMPT infants and also emphasizes that mothers of LMPT infants should receive qualified, extended lactation support, and frequent follow‐up. Individualized feeding plans should be promoted. Hospital discharge should be delayed until LMPT infants have a safe discharge plan that takes into account local situation and resources.

In the LMPT population, the need for active nutritional support increases with lower gestational ages. There may be a role for enhanced nutritional support including the use of human milk fortifier, enriched formula, parenteral nutrition, and/or additional supplements, depending on factors, such as gestational age, birth weight, and significant comorbidities. Further research is needed to assess the benefits (improved nutrient intakes) versus risks (interruption of breast‐feeding) of providing nutrient‐enrichment to the LMPT infant.
Autoimmunity and Delayed Diagnosis in Pediatric Idiopathic Pulmonary Hemosiderosis
Authors: AlJassmi Abdulrahman M.
Published: May 2019

Idiopathic pulmonary hemosiderosis is characterized by a triad of iron-deficiency anemia, hemoptysis, and radiographic diffuse lung infiltrates. However, the inconsistent initial presentation in children may cause a significant delay in diagnosis. Autoimmune reactivity seems to be the most acceptable theory of pathogenesis. We reported an 8-year-old boy presenting with a cough, fever, and difficulty breathing with a history of iron-deficiency anemia and an abnormal autoimmune response in the last 3 years. Perinuclear antineutrophil cytoplasmic antibodies were positive and chest computed tomography revealed patchy ground glass haziness. Bronchoalveolar lavage fluid showed hemosiderin-laden macrophages. The respiratory symptoms improved with oral corticosteroids.
Elevation of Postmortem Cerebrospinal Fluid Sodium and Chloride Levels Is a Potential Adjunct Test in the Diagnosis of Salt Water Drowning
Authors: Garland Jack , McCarthy Sinead , Hensby-Bennett Sarah , Philcox Winston , O'Regan Toni , Rousseau Guillaume , Palmiere Cristian , Elstub Hannah , Cala Allan , Clifton Leah , Lam Leo , Barker Claire , Ondruschka Benjamin , Woydt Lina , Spark Amy , Kesha Kilak , Morrow Paul , Glenn Charley , Stables Simon , Tse Rexson
Published: May 2019

Postmortem vitreous humor biochemistry is a useful test in the diagnosis of salt water drowning (SWD). A significant limitation of vitreous humor is the potential effect of prolonged immersion. A recent animal study and case report suggested that cerebrospinal fluid biochemistry may be an alternative to vitreous because it is more resistant to the effects of immersion, given its protected anatomical location. This study compared postmortem cerebrospinal fluid sodium and chloride (PMCSC) levels collected via ventricular aspiration (PMCSC_V) and via lumbar puncture (PMCSC_L) in 13 SWD and 31 nonimmersion deaths. It showed a significant elevation in PMCSC levels in SWD deaths for both PMCSC_V and PMCSC_L (P < 0.05). The areas under the curve on the receiver operating characteristic curves for PMCSC_V and PMCSC_L were 0.73 and 0.83, respectively. The optimal cutoff for PMCSC_V was 216 mmol/L (sensitivity, 0.60; specificity, 0.72; likelihood ratio, 1.80; positive predictive value, 0.45) and for PMCSC_L was 241 mmol/L (sensitivity, 0.78; specificity, 0.73; likelihood ratio, 2.89; positive predictive value, 0.46). This study supports PMCSC levels as another biochemical test that can potentially aid in the diagnosis of SWD, particularly in cases where vitreous humor samples are unavailable or uninterpretable.
Perinephric Fat Stranding on Postmortem Computed Tomography Scan in Acute Pyelonephritis
Authors: Garland Jack , Olds Kelly , Tse Rexson
Published: May 2019

Infection/inflammation of solid organ can be difficult to appreciate at postmortem computed tomography (CT) scan (PMCT). Perinephric fat stranding is a clinical CT finding to suggest pyelonephritis; however, PMCT scan showing perinephric fat stranding in acute pyelonephritis has not been documented in the forensic literature. We present a death from acute pyelonephritis in a setting of hypertensive heart disease, in which the unenhanced PMCT performed before postmortem examination was able to show florid bilateral perinephric fat stranding. This PMCT finding subsequently guided the pathologist to pay special attention to the kidney and take appropriate microbiology specimens to confirm the diagnosis. Perinephric fat stranding on PMCT may be a useful sign to alert the pathologist to consider acute pyelonephritis during the postmortem examination.
Nuclear NR4A3 Immunostaining Is a Specific and Sensitive Novel Marker for Acinic Cell Carcinoma of the Salivary Glands
Authors: Haller Florian , Skálová Alena , Ihrler Stephan , Märkl Bruno , Bieg Matthias , Moskalev Evgeny A. , Erber Ramona , Blank Susanne , Winkelmann Christa , Hebele Simone , Baněčková Martina , Wiemann Stefan , Müller Sarina , Zenk Johannes , Eils Roland , Iro Heinrich , Hartmann Arndt , Agaimy Abbas
Published: May 2019

Recently, we discovered the recurrent genomic rearrangement [t(4;9)(q13;q31)] enabling upregulation of the transcription factor Nuclear Receptor Subfamily 4 Group A Member 3 (NR4A3) through enhancer hijacking as the oncogenic driver event in acinic cell carcinoma (AciCC) of the salivary glands. In the current study, we evaluated the usefulness of NR4A3 immunostaining and NR4A3 fluorescence in situ hybridization (FISH) in the differential diagnosis of AciCC, comparing a total of 64 AciCCs including 17% cases with high-grade transformation, 29 secretory (mammary analog) carcinomas (MASC), and 70 other salivary gland carcinomas. Nuclear NR4A3 immunostaining was a highly specific (100%) and sensitive (98%) marker for AciCC with only 1 negative case, whereas NR4A3 FISH was less sensitive (84%). None of the MASCs or other salivary gland carcinomas displayed any nuclear NR4A3 immunostaining. The recently described HTN3-MSANTD3 gene fusion was observed in 4 of 49 (8%) evaluable AciCCs, all with nuclear NR4A3 immunostaining. In summary, NR4A3 immunostaining is a highly specific and sensitive marker for AciCC, which may be especially valuable in cases with high-grade transformation and in “zymogen granule”-poor examples within the differential diagnostic spectrum of AciCC and MASC.
International Study of the Epidemiology of Platelet Transfusions in Critically Ill Children With an Underlying Oncologic Diagnosis
Authors: Nellis Marianne E. , Goel Ruchika , Karam Oliver , Cushing Melissa M. , Davis Peter J. , Steiner Marie E. , Tucci Marisa , Stanworth Simon J. , Spinella Philip C.
Published: May 2019

Objectives:

To describe the epidemiology of platelet transfusions in critically ill children with an underlying oncologic diagnosis and to examine effects of prophylactic versus therapeutic transfusions.

Design:

Subgroup analysis of a prospective, observational study.

Setting:

Eighty-two PICUs in 16 countries.

Patients:

All children (3 d to 16 yr old) who received a platelet transfusion during one of the six predefined screening weeks and had received chemotherapy in the previous 6 months or had undergone hematopoietic stem cell transplantation in the last year.

Interventions:

None.

Measurements and Main Results:

Of the 548 patients enrolled in the parent study, 237 (43%) had an underlying oncologic diagnosis. In this population, 71% (168/237) of transfusions were given prophylactically, and 59% (139/237) of transfusions were given at a total platelet count greater than 20 × 109/L, higher than the current recommendations. Those with an underlying oncologic diagnosis were significantly older, and received less support including less mechanical ventilation, fewer medications that affect platelet function, and less use of extracorporeal life support than those without an underlying oncologic diagnosis. In this subpopulation, there were no statistically significant differences in median (interquartile range) platelet transfusion thresholds when comparing bleeding or nonbleeding patients (50 × 109/L [10–50 × 109/L] and 30 × 109/L [10–50 × 109/L], respectively [p = 0.166]). The median (interquartile range) interval transfusion increment in children with an underlying oncologic diagnosis was 17 × 109/L (6–52 × 109/L). The presence of an underlying oncologic diagnosis was associated with a poor platelet increment response to platelet transfusion in this cohort (adjusted odds ratio, 0.46; 95% CI, 0.22–0.95; p = 0.035).

Conclusions:

Children with an underlying oncologic diagnosis receive nearly half of platelet transfusions prescribed by pediatric intensivists. Over half of these transfusions are prescribed at total platelet count greater than current recommendations. Studies must be done to clarify appropriate indications for platelet transfusions in this vulnerable population.
Antibiotic Prophylaxis for Open Chest Management After Pediatric Cardiac Surgery
Authors: Hatachi Takeshi , Sofue Toshiki , Ito Yukie , Inata Yu , Shimizu Yoshiyuki , Hasegawa Moyu , Kugo Yosuke , Yamauchi Sanae , Iwai Shigemitsu , Takeuchi Muneyuki
Published: May 2019

Objectives:

Although open chest management optimizes hemodynamics after cardiac surgery, it increases postoperative infections and leads to increased mortality. Despite the importance of antibiotic prophylaxis during open chest management, no specific recommendations exist. We aimed to compare the occurrence rates of bloodstream infection and surgical site infection between the different prophylactic antibiotic regimens for open chest management after pediatric cardiac surgery.

Design:

Retrospective, single-center, observational study.

Setting:

PICU at a tertiary children’s hospital.

Patients:

Consecutive patients younger than or equal to 18 years old with open chest management after cardiac surgery followed by delayed sternal closure, between January 2012 and June 2018.

Interventions:

None.

Measurements and Main Results:

We compared the composite occurrence rate of postoperative bloodstream infection and surgical site infection within 30 days after cardiac surgery between three prophylactic antibiotic regimens: 1) cefazolin, 2) cefazolin + vancomycin, and 3) vancomycin + meropenem. In 63 pediatric cardiac surgeries with open chest management, 17 bloodstream infections, and 12 surgical site infections were identified postoperatively. The composite occurrence rates of bloodstream infection and surgical site infection were 10 of 15 (67%), 10 of 19 (53%), and nine of 29 (31%) in the cefazolin, cefazolin + vancomycin, and vancomycin + meropenem regimens, respectively (p = 0.07). After adjusting for age, open chest management duration, extracorporeal membrane oxygenation use, and nasal methicillin-resistant Staphylococcus aureus colonization in multivariable analysis, there was no significant difference between the cefazolin and the cefazolin + vancomycin regimens (p = 0.19), while the vancomycin + meropenem regimen had a lower occurrence rate of bloodstream infection and surgical site infection than the cefazolin regimen (odds ratio, 0.0885; 95% CI, 0.0176–0.446; p = 0.003).

Conclusions:

In this study, a lower occurrence rate of postoperative bloodstream infection and surgical site infection was observed among patients with broad-spectrum antibiotic regimen after pediatric cardiac surgery with open chest management. Further studies, ideally randomized controlled studies investigating the efficacy of broad-spectrum antibiotics and their complications, are warranted before routine implementation of broad-spectrum prophylactic antibiotic regimen.
Advanced Glycation End Products Are Associated With Inflammation and Endothelial Dysfunction in HIV
Authors: El Kamari Vanessa , Thomas Alicia , Shan Lingpeng , Sattar Abdus , Monnier Vincent , Howell Scott K. , Beisswenger Paul J. , McComsey Grace A.
Published: May 2019

Objective:

To compare levels of advanced glycation end products (AGEs) between HIV-infected patients and uninfected controls and assess the relationship between AGEs, HIV, inflammation, and endothelial dysfunction.

Design:

Cross-sectional study involving 90 individuals (68 HIV+ and 22 healthy controls matched by age and sex).

Methods:

AGE levels were assessed using 3 different modalities: free AGEs were measured in the serum, skin autofluorescence (AF) was determined with a noninvasive reader, and dietary AGEs were estimated using 24-hour dietary recalls. Markers of inflammation, immune activation, and endothelial dysfunction were also measured. Wilcoxon rank-sum and χ2 tests were used to compare AGEs between groups. Spearman correlations were used to explore relationships between variables while adjusting for different covariates.

Results:

Overall, 71% were men and 68% were African American, with a median age of 53 years. Among HIV-infected individuals, all participants were on antiretroviral therapy by design, and most participants (78%) had an undetectable HIV-1 RNA level (≤20 copies/mL). Skin AF and serum AGEs were significantly higher in HIV-infected participants compared with uninfected controls (P < 0.01), whereas no differences in dietary AGEs were found between groups (P = 0.2). In the HIV-infected group, but not in controls, skin AF and circulating AGEs were significantly associated with inflammatory and oxidative markers, and with markers of endothelial dysfunction.

Conclusions:

These results suggest intrinsic production of AGE in HIV-infected individuals. The relationship between serum/skin AGE and inflammatory, oxidative, and cardiovascular markers highlights the potential implications of AGEs in chronic inflammation and endothelial dysfunction in HIV, suggesting a new potential target for HIV-associated heightened inflammation and cardiovascular risk.
TNF-Related Apoptosis-Inducing Ligand Receptor 1 in Patients With Ankylosing Spondylitis
Authors: Karadag Duygu Temiz , Tekeoglu Senem , Yazici Ayten , Isik Ozlem Ozdemir , Eraldemir Fatma Ceyla , Cefle Ayse
Published: May 2019

Objectives

Tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) belongs to the tumor necrosis factor (TNF) superfamily and is reported to play a role in autoimmune diseases. In this study, we aimed to measure serum TRAIL receptor 1 (TRAIL-R1) concentration and assess any phenotypic relationship in patients with ankylosing spondylitis (AS).

Methods

Fifty-three patients with AS were recruited from August 2014 to December 2014 cross-sectionally. Fifty-three sex- and age-matched healthy controls were also recruited. Serum TRAIL-R1 concentrations were measured using an enzyme-linked immunosorbent assay. The association between serum TRAIL-R1, TNF-α, disease activity indices, markers of systemic inflammation, and clinical features were evaluated.

Results

Serum TRAIL-R1 and TNF-α levels were increased in patients with AS compared with healthy controls (4.5 ± 2.3 vs 3.5 ± 2.3 pg/mL, p = 0.036; 3.8 [1.6–7.7] vs 2.0 [0.21–5.7] pg/mL, p = 0.048, respectively). Serum TRAIL-R1 displayed a medium positive correlation with serum TNF-α concentrations (r = 0.412; p = 0.002). Serum TRAIL-R1 concentration was higher in human leucocyte antigen (HLA)-B27–positive patients compared with non–HLA-B27 patients (5.5 ± 2.2 vs 3.1 ± 1.6 pg/mL, p < 0.001). No relationship was found between serum TRAIL-R1 concentration and disease activity scores.

Conclusions

This study confirms that serum TRAIL-R1 levels are higher in AS patients than healthy controls. The persistence of significantly elevated serum TRAIL-R1 levels, even in patients with low disease activity or after excluding biologic treatment, and the association with HLA-B27 positivity, warrants further investigation due to the unclear role of TRAIL-R1 in the pathophysiology of AS.
Imaging Evaluation of Lung Transplantation Patients
Authors: Amadi Chiemezie C. , Galizia Mauricio S. , Mortani Barbosa Eduardo J.
Published: May 2019

Lung transplantation is an established therapeutic option for patients with irreversible end-stage pulmonary disease limiting life expectancy and quality of life. Common indications for lung transplantation include chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, cystic fibrosis, pulmonary arterial hypertension, and alpha-1 antitrypsin deficiency. Complications of lung transplantation can be broadly divided etiologically into surgical, infectious, immunologic, or neoplastic. Moreover, specific complications often occur within a certain time interval following surgery, which can be broadly classified as early (<6 wk), intermediate (6 wk to 6 mo), and late (>6 mo). Thus, each group of complications can further be categorized on the basis of the time continuum from transplantation. Imaging, primarily by high-resolution computed tomography, plays a critical role in early diagnosis of complications after lung transplantation. Early recognition of complications by the radiologist, and initiation of therapy, contributes to improved morbidity and mortality. However, accurate diagnosis is only feasible if one has a thorough understanding of the major etiologic categories of complications and how they relate to the time course since transplantation. We review imaging manifestations of lung transplant complications via a framework that includes the following major etiologic categories: surgical; infectious; immunologic; and neoplastic; and the following time frames: surgery to 6 weeks; 6 weeks to 6 months; and beyond 6 months. We propose this approach as a logical, evidence-based algorithm to construct a narrow, optimal differential diagnosis of lung transplantation complications.
Systematic reviews of scores and predictors to trigger activation of massive transfusion protocols
Authors: Shih Andrew W. , Al Khan Shadhiya , Wang Alan Ying-Hsu , Dawe Philip , Young Pang Y. , Greene Adam , Hudoba Monika , Vu Erik
Published: May 2019

BACKGROUND

The use of massive transfusion protocols (MTPs) in the resuscitation of hemorrhaging trauma patients ensures rapid delivery of blood products to improve outcomes, where the decision to trigger MTPs early is important. Scores and tools to predict the need for MTP activation have been developed for use to aid with clinical judgment. We performed a systematic review to assess (1) the scores and tools available to predict MTP in trauma patients, (2) their clinical value and diagnostic accuracies, and (3) additional predictors of MTP.

METHODS

MEDLINE, EMBASE, and CENTRAL were searched from inception to June 2017. All studies that utilized scores or predictors of MTP activation in adult (age, ≥18 years) trauma patients were included. Data collection for scores and tools included reported sensitivities and specificities and accuracy as defined by the area under the curve of the receiver operating characteristic.

RESULTS

Forty-five articles were eligible for analysis, with 11 validated and four unvalidated scores and tools assessed. Of four scores using clinical assessment, laboratory values, and ultrasound assessment the modified Traumatic Bleeding Severity Score had the best performance. Of those scores, the Trauma Associated Severe Hemorrhage score is most well validated and has higher area under the curve of the receiver operating characteristic than the Assessment of Blood Consumption and Prince of Wales scores. Without laboratory results, the Assessment of Blood Consumption score balances accuracy with ease of use. Without ultrasound use, the Vandromme and Schreiber scores have the highest accuracy and sensitivity respectively. The Shock Index uses clinical assessment only with fair performance. Other clinical variables, laboratory values, and use of point-of-care testing results were identified predictors of MTP activation.

CONCLUSION

The use of scores or tools to predict MTP need to be individualized to hospital resources and skill set to aid clinical judgment. Future studies for triggering nontrauma MTP activations are needed.

LEVEL OF EVIDENCE

Systematic review, level III.
Alzheimer Disease-associated Cortical Atrophy Does not Differ Between Chinese and Whites
Authors: Fan Jia , Tse Marian , Carr Jessie S. , Miller Bruce L. , Kramer Joel H. , Rosen Howard J. , Bonham Luke W. , Yokoyama Jennifer S.
Published: May 2019

Purpose:

To assess whether there are differences in Alzheimer disease (AD)-associated atrophy regions in Chinese and white patients with AD versus cognitively normal older adults, and to test whether associations between clinical severity and gray matter volume are similar or different across these ethnic groups in a cross-sectional analysis.

Materials and Methods:

Chinese and white patients with AD, individuals with mild cognitive impairment, and cognitively normal controls (46 white and 48 Chinese) were clinically evaluated at an academic center within 1 year of magnetic resonance imaging acquisition. Clinical severity was assessed using the Clinical Dementia Rating Sum of Boxes and cortical atrophy was measured using voxel-based morphometry as well as Freesurfer. Chinese and white cohorts were demographically matched for age, sex, and education.

Results:

Clinical severity by diagnosis was similar across ethnicities. Chinese and white patient groups showed similar amounts of atrophy in the regions most affected in AD after accounting for demographic variables and head size. There was no significant difference between ethnic groups when compared by atrophy and clinical severity.

Conclusions:

Our study suggests that Chinese and white patients with AD, when matched demographically, are clinically and neuroanatomically similar on normalized measures of cortical atrophy and clinical severity.
Tissue tropism in parasitic diseases
Authors: Silva Pereira Sara , Trindade Sandra , De Niz Mariana , Figueiredo Luisa M.
Published: May 2019

Parasitic diseases, such as sleeping sickness, Chagas disease and malaria, remain a major cause of morbidity and mortality worldwide, but particularly in tropical, developing countries. Controlling these diseases requires a better understanding of host–parasite interactions, including a deep appreciation of parasite distribution in the host. The preferred accumulation of parasites in some tissues of the host has been known for many years, but recent technical advances have allowed a more systematic analysis and quantifications of such tissue tropisms. The functional consequences of tissue tropism remain poorly studied, although it has been associated with important aspects of disease, including transmission enhancement, treatment failure, relapse and clinical outcome. Here, we discuss current knowledge of tissue tropism in
Trypanosoma
infections in mammals, describe potential mechanisms of tissue entry, comparatively discuss relevant findings from other parasitology fields where tissue tropism has been extensively investigated, and reflect on new questions raised by recent discoveries and their potential impact on clinical treatment and disease control strategies.
Evolution by Schrödinger equation of Aharonov–Berry superoscillations in centrifugal potential
Authors: Colombo F. , Gantner J. , Struppa D. C.
Published: May 2019

In recent years, we have investigated the evolution of superoscillations under Schrödinger equation with non-singular potentials. In all those cases, we have shown that superoscillations persist in time. In this paper, we investigate the centrifugal potential, which is a singular potential, and we show that the techniques developed to study the evolution of superoscillations in the case of the Schrödinger equation with a quadratic Hamiltonian apply to this setting. We also specify, in the case of the centrifugal potential, the notion of super-shift of the limit solution, a fact explained in the last section of this paper. It then becomes apparent that superoscillations are just a particular case of super-shift.
Elastic shocks in relativistic rigid rods and balls
Authors: Costa João L. , Natário José
Published: May 2019

We study the free boundary problem for the ‘hard phase’ material introduced by Christodoulou in (Christodoulou 1995Arch. Ration. Mech. Anal.130, 343–400), both for rods in (1 + 1)-dimensional Minkowski space–time and for spherically symmetric balls in (3 + 1)-dimensional Minkowski space–time. Unlike Christodoulou, we do not consider a ‘soft phase’, and so we regard this material as an elastic medium, capable of both compression and stretching. We prove that shocks must be null hypersurfaces, and derive the conditions to be satisfied at a free boundary. We solve the equations of motion of the rods explicitly, and we prove existence of solutions to the equations of motion of the spherically symmetric balls for an arbitrarily long (but finite) time, given initial conditions sufficiently close to those for the relaxed ball at rest. In both cases we find that the solutions contain shocks if and only if the pressure or its time derivative do not vanish at the free boundary initially. These shocks interact with the free boundary, causing it to lose regularity.
Diversification of light capture ability was accompanied by the evolution of phycobiliproteins in cryptophyte algae
Authors: Greenwold Matthew J. , Cunningham Brady R. , Lachenmyer Eric M. , Pullman John Michael , Richardson Tammi L. , Dudycha Jeffry L.
Published: May 2019

Evolutionary biologists have long sought to identify phenotypic traits whose evolution enhances an organism's performance in its environment. Diversification of traits related to resource acquisition can occur owing to spatial or temporal resource heterogeneity. We examined the ability to capture light in the Cryptophyta, a phylum of single-celled eukaryotic algae with diverse photosynthetic pigments, to better understand how acquisition of an abiotic resource may be associated with diversification. Cryptophytes originated through secondary endosymbiosis between an unknown eukaryotic host and a red algal symbiont. This merger resulted in distinctive pigment–protein complexes, the cryptophyte phycobiliproteins, which are the products of genes from both ancestors. These novel complexes may have facilitated diversification across environments where the spectrum of light available for photosynthesis varies widely. We measured light capture and pigments under controlled conditions in a phenotypically and phylogenetically diverse collection of cryptophytes. Using phylogenetic comparative methods, we found that phycobiliprotein characteristics were evolutionarily associated with diversification of light capture in cryptophytes, while non-phycobiliprotein pigments were not. Furthermore, phycobiliproteins were evolutionarily labile with repeated transitions and reversals. Thus, the endosymbiotic origin of cryptophyte phycobiliproteins provided an evolutionary spark that drove diversification of light capture, the resource that is the foundation of photosynthesis.
Estimating probabilistic dark diversity based on the hypergeometric distribution
Authors: Carmona Carlos P. , Szava-Kovats Robert , Pärtel Meelis
Published: May 2019

The biodiversity of a site includes the absent species from the region that are theoretically able to live in the site’s particular ecological conditions. These species constitute the dark diversity of the site. Unlike present species, dark diversity is unobservable and can only be estimated. Most existing methods to designate dark diversity act in a binary fashion. However, dark diversity is more suitably defined as a fuzzy set—in which the degree of certainty about species membership is expressed as a probability.

We present a new method to estimate probabilistic dark diversity based on the hypergeometric distribution. The method relies on co-occurrences to infer the strength of the association between pairs of species and assign probabilistic adscription to dark diversity to absent species. We compare it with two established methods to estimate dark diversity (Beals index and favorability correction). To test the methods, we created simulations based on individual agents in which the suitability of each species in each site is known. We compared the ability of the methods to accurately predict suitability and the size of dark diversity, and compared their sensitivity to data availability. Further, we assessed the methods in two real datasets with nested sampling designs.

Our simulations revealed that predictions of the Beals method were extremely sensitive to species frequency, and predicted suitability poorly. The Favorability transformation corrected this relationship, but did still predicted extremely low probabilities for species with very little information. The Hypergeometric method outperformed the Beals and Favorability methods in all considered aspects in the simulations and displayed better characteristics in the real datasets.

Probabilistic consideratiosn of biodiversity will help to acknowledge the uncertainty associated with ecological information. Although the Beals method has been described as the best estimator of dark diversity, it should be preferred only when the goal is to predict future apperances of species. However, studies on dark diversity should focus on the ecological affinities of species. The Hypergeometric method is the most promising method to estimate probabilistic dark diversity and species pool composition based on co-occurrences.
Fruit and vegetable expenditure disparities: evidence from Chile
Authors: Carreño Pia , Silva Andres
Published: May 2019

Purpose

The purpose of this paper is to explore fruit and vegetable (FV) procurement disparity across income groups.

Design/methodology/approach

This study uses mean comparison and quintile regression to explain FVs variations.

Findings

Households from the highest income quantile spend more than two times on FVs than households from the lowest quantile; however, this expenditure disparity is largely mitigated in terms of purchase quantity. This paper presents evidence that, rather than quantity discounts or income neighborhood, the type of store (traditional markets vs supermarkets) plays a relevant role in explaining the smaller gap in terms of purchase quantity.

Research limitations/implications

Traditional markets help low-income households access low-cost FVs.

Social implications

The authors generate evidence to show that traditional markets play a relevant role to supply affordable FV to low-income households.

Originality/value

The paper used a high-quality and uncommon data set. It is a topic of high social impact.
Barriers in contractual scope management of international development projects in Afghanistan
Authors: Hilali Ahmadullah , Charoenngam Chotchai , Barman Ankita
Published: May 2019

Purpose

For construction and management, the existing codes of practice of international organizations such as US Army Corps of Engineers, the Asian Development Bank, the World Bank, the United Nations Office for Project Services, etc., often prove ineffective when applied in post-war countries like Afghanistan. Domestic contractors faced maximum challenges in contractual scope management, which was implemented by such organizations based on their existing codes of practice. The purpose of this paper is to understand these barriers in scope management as faced by the domestic contractors of Afghanistan.

Design/methodology/approach

The research employs a mixed methodology to cater to its objectives. Face-to-face structured interviews of 14 industry experts and extensive literature review were conducted to identify unique barriers pertaining to Afghanistan construction industry. Further, quantitative assessment of these barriers through the statistical tools of “mean score ranking,” “Kendall’s test” and “independent sample t-test” was carried out to understand the severity of the barriers.

Findings

In total, 39 unique barriers were identified under the groups of “scope formulation,” “scope completeness,” “scope pricing,” “scope implementation” and “scope change control.” The consequential impacts of these barriers and their existence at different stages of the project were illustrated. The most severe barriers were identified as the “inadequacy of site investigation reports” and the “unavailability of resources in local markets.”

Originality/value

The understanding of the challenges faced by local stakeholders, as highlighted by this study, can be utilized by these international organizations in their strategy and planning to ensure successful projects while also propagating the adoption of sustainable construction practices.
Innovation capabilities for global R&D projects in subsidiaries
Authors: Tarraço Elisangela Lazarou , Bernardes Roberto Carlos , Borini Felipe Mendes , Rossetto Dennys Eduardo
Published: May 2019

Purpose

Is the development of local innovation capabilities enough for foreign subsidiaries in emerging markets to be able to integrate into global R&D projects? The authors argue that it is not. The purpose of this paper is to show the central role of R&D capacities when it comes to inserting foreign subsidiaries in emerging markets into global R&D projects.

Design/methodology/approach

The study investigated 131 foreign multinational subsidiaries operating in Brazil. For each subsidiary, the authors surveyed two to five directors or C-level executives from innovation, R&D, engineering, product development and projects. the authors used structural equation modeling for analysis.

Findings

The results indicate that product and process innovations alone do not guarantee the insertion of the emerging market subsidiaries into global innovation projects. Such insertion depends on the subsidiary’s accumulation of R&D capacities.

Practical implications

The results reinforce the central issue of building product and process innovation capabilities as the first step toward a blueprint for global projects. However, the effort is not limited to these initiatives. Product and process innovation efforts need be reverted in headquarters’ eyes in order for subsidiaries to gain R&D center status. To achieve this, subsidiaries must align their technological innovations with multinational corporations’ innovation strategies.

Originality/value

In authors’ view, this study contributes to the literature in three main areas: the evolutionary process of innovation capability in subsidiaries, the reverse innovation debate and the discussion of subsidiaries’ initiatives.
Empowerment and initiative: the mediating role of obligation
Authors: Wikhamn Wajda , Selart Marcus
Published: May 2019

Purpose

The purpose of this paper is to investigate the extent to which psychological empowerment and felt obligation can explain variations in personal initiative.

Design/methodology/approach

Employees from a Swedish organization participated in a web-based survey.

Findings

Psychological empowerment is important for enhancing proactive behavior at work, but its dimensions relate differently to personal initiative. Felt obligation mediates the relationship between psychological empowerment and personal initiative, but only for two dimensions of empowerment (meaningfulness and competence).

Originality/value

The paper contributes to our understanding of how employees’ feeling of obligation explains one form of proactive behavior. It also highlights the overlooked distinctiveness of psychological empowerment dimensions in predicting personal initiative at work.
Applying GRA to analyze influencing factors of patients’ financial burden
Authors: Li Xiaoning , Liao Xinbo , Zhong Qingwen , Zheng Kai , Chen Shaoxing , Chen Xiao-Jun , Zhu Jin-Xiu , Yang Hongyuan
Published: May 2019

Purpose

The purpose of this paper is to analyze the influencing factors of patients’ financial burden through a case study of hospital on public‒private partnerships (PPP) model (Chaonan Minsheng Hospital of Guangdong Province) and provide some useful information to policymakers for better development of hospitals on PPP model.

Design/methodology/approach

There are total six indicators that are defined as patients’ financial burden, basing on the policy of “indicators of medical quality management and control on the third level large general hospital (2011 edition),” issued by Chinese Government. In total, 23 potentially influencing factors of patients’ financial burden for hospital on PPP model were chosen from the above policy. The five-year (2007‒2011) data for the above 29 indicators come from statistic department of hospital on PPP model. Grey relational analysis (GRA) was applied to analyze the influencing factors of patients’ financial burden for hospital on PPP model.

Findings

A clear rank of influencing factors of patients’ financial burden is obtained and suggestions are provided from results of GRA, which provide reference for policymakers of hospital on PPP model. The five main influencing factors of patients’ financial burden for hospital on PPP model, in sequence, are rescuing critical ill patients on emergency, rescuing critical ill inpatients, inpatient bed occupancy rate, working days per bed and medical building area.

Originality/value

The study on the influencing factors of patients’ financial burden for hospital on PPP model not only provides decision-making for policymaker of hospital and controlling of medical expenditure but also contributes to release patients’ financial burden for hospitals on PPP model.
Emerging procurement technology: data analytics and cognitive analytics
Authors: Handfield Robert , Jeong Seongkyoon , Choi Thomas
Published: May 2019

Purpose

The purpose of this paper is to elucidate the emerging landscape of procurement analytics. This paper focuses on the following questions: what are the current and future state of procurement analytics?; what changes in the procurement process will be required to enable integration of analytical solutions?; and what future areas of research arise when considering the future state of procurement analytics?

Design/methodology/approach

This paper employs a qualitative approach that relies on three sources of information: executive interviews, a review of current and emerging technology platforms and a small survey of subject matter experts in the field.

Findings

The procurement analytics landscape developed in this research suggests that the authors will continue to see major shifts in the sourcing and supply chain technology environment in the next five years. However, there currently exists a low usage of advanced procurement analytics, and data integrity and quality issues are preventing significant advances in analytics. This study identifies the need for organizations to establish a coherent approach to collection and storage of trusted organizational data that build on internal sources of spend analysis and contract databases. In addition, currentad hocapproaches to capturing unstructured data must be replaced by a systematic data governance strategy. An important element for organizations in this evolution is managing change and the need to nourish an analytic culture.

Originality/value

While the majority of forward-looking research and reports merely project broad technological impact of cognitive analytics and big data, much of it does not provide specific insights into functional impacts such as the impact on procurement. The analysis of this study provides us with a clear view of the potential for business analytics and cognitive analytics to be employed in procurement processes, and contributes to development of related research topics for future study. In addition, this study suggests detailed implementation strategies of emerging procurement technologies, contributing to the existing body of the literature and industry reports.
Whether the industrial workers of slums have access to job insurance?
Authors: Banerjee Shashwati , Goswami Kishor
Published: May 2019

Purpose

Securing a job in an industry is a boon for most of the slum dwellers. When the primary earner of a slum household suffers from occupational illness and injuries, without insurance coverage or partial coverage of insurance, this boon may become a curse in the long run. The occupational security and safety along with the fact that whether such workers are insured is an important aspect and has a close link with the expenditure on illness. Thus, the accessibility to employees’ insurance in the risky industrial occupation, particularly for slum dwellers, is crucial to protect them from falling into poverty. Studies on occupational health of the poor workers are either limited to informal sectors or remain industry specific and the analysis of their accessibility to job insurance is rarely done. The paper aims to discuss these issues.

Design/methodology/approach

The research questions are framed to analyze the types of insurance accessible to workers across various industries; the accessibility to insurance, however, varying across risk intensities of various industries; and the determinants of insurance accessibility of the industrial workers living in slums. The determinants of accessibility of job insurance are analyzed with a binary Logit model. A multi-stage random sampling technique is used to collect the primary data from 320 industrial workers living in the slums of the Indian state of West Bengal.

Findings

The industrial workers, irrespective of the types of industries, are exposed to a high-risk category without proper job insurance. The higher industrial income is not adequate to prevent financial hardships. Access to insurance is more likely for the respondents with job tenure of more than two years and less likely for the workers who are working for more than eight hours per day.

Social implications

This study provides a significant insight to the policymakers concerning health dynamics of the slum dwellers, which can improve their livelihood.

Originality/value

The analysis of the industry-specific risk intensities with accessibility to insurance contributes to understanding the coverage of the insurance scheme for the workers in slums.
Investigation of material removal rate and surface roughness using multi-objective optimization for micro-milling of inconel 718
Authors: Lu Xiaohong , Wang FuRui , Xue Liang , Feng Yixuan , Liang Steven Y.
Published: May 2019

Purpose

The purpose of this study is to realize the multi-objective optimization for MRR and surface roughness in micro-milling of Inconel 718.

Design/methodology/approach

Taguchi method has been applied to conduct experiments, and the cutting parameters are spindle speed, feed per tooth and depth of cut. The first-order models used to predict surface roughness and MRR for micro-milling of Inconel 718 have been developed by regression analysis. Genetic algorithm has been utilized to implement multi-objective optimization between surface roughness and MRR for micro-milling of Inconel 718.

Findings

This paper implemented the multi-objective optimization between surface roughness and MRR for micro-milling of Inconel 718. And some conclusions can be summarized. Depth of cut is the major cutting parameter influencing surface roughness. Feed per tooth is the major cutting parameter influencing MRR. A number of cutting parameters have been obtained along with the set of pareto optimal solu-tions of MRR and surface roughness in micro-milling of Inconel 718.

Originality/value

There are a lot of cutting parameters affecting surface roughness and MRR in micro-milling, such as tool diameter, depth of cut, feed per tooth, spindle speed and workpiece material, etc. However, to the best our knowledge, there are no published literatures about the multi-objective optimization of surface roughness and MRR in micro-milling of Inconel 718.
Supportive leadership and EVB
Authors: Elsaied Mervat
Published: May 2019

Purpose

The purpose of this paper is to investigate the relationship between supportive leadership and employee voice behavior by examining the mediating role of employee advocacy, and the moderating role of proactive personality.

Design/methodology/approach

The model was tested by using data that were collected from 402 supervisors, and 87 subordinates who were working in 6 firms belonging to the stone and Glass sector, in the Tenth Ramadan city, Egypt. The employees and their immediate supervisors provided data on separated questionnaires, and different occasions. Then, an identification number was used by the author to match each employee questionnaire with the response of his/ her immediate supervisor.

Findings

The results revealed that employee advocacy fully mediated the positive relationship between supportive leadership and employee voice behavior. Also, it also found that proactive personality moderated the relationship between supportive leadership and employee voice behavior, such that the relationship was stronger for people lower rather than higher in proactive personality.

Originality/value

This empirical paper provides preliminary evidence of the mediating effect of employee advocacy in the positive relationship between supportive leadership and employee voice behavior. The model extends the existing results by adding substantive moderate proactive personality to explain how the effect of supportive leadership on employee voice behavior.