bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of meteorological factors with pediatric acute appendicitis in China
Authors: Zhang Yao , Lyu Feng-xiang , Kang Quan , Dong Zi-xing , Zhao Tian-xin , Xie Sheng-nan , Luo Qing
Published: October 2018

Acute appendicitis (AA) affects between 7% and 8% of the world population and is one of the most common general surgical emergencies. The concept of seasonal patterns in the incidence of AA remains controversial. Thus, this study aimed to investigate whether meteorological factors are related to variations in the rate of pediatric AA cases at the Children's Hospital in Chongqing, China.

In total, in this retrospective survey, 3436 children younger than 18 years who had been hospitalized with AA from January 1, 2008 to December 31, 2013 were enrolled, and the meteorological factors during this period were collected.

Patients with AA showed a male/female ratio of 1.81:1; the highest incidence age ranged from 6 to 12 years old (P < .0001). The highest incidences of pediatric AA occurred in summer and autumn, with a peak in September and a trough in February. Pearson correlation analysis showed that the monthly mean temperature (r = 0.357, P = .001), monthly mean relative humidity (r = −0.357, P = .001), and monthly mean sunshine duration (r = 0.235, P = −0.031) were relatively weak correlated with pediatric AA. Multiple linear regression analysis indicated that pediatric AA occurrence was positively affected by monthly mean temperature (P < .0001) and negatively affected by monthly mean humidity (P < .0001) and monthly sum of sunshine (P < .0001), while monthly mean air pressure (P = .092), monthly wind speed (P = .143) and monthly precipitation (P = .297) were marginally associated with pediatric AA.

Pediatric AA is associated with climatic factors. Specifically, pediatric AA is more likely related to the following meteorological conditions of: high temperature (20 °C–30 °C), low humidity, and less sunshine.
Association of angiotensin-converting enzyme 2 gene polymorphism and enzymatic activity with essential hypertension in different gender
Authors: Zhang Qi , Cong Mingyu , Wang Ningning , Li Xueyan , Zhang Hao , Zhang Keyong , Jin Ming , Wu Nan , Qiu Changchun , Li Jingping
Published: October 2018

Angiotensin-converting enzyme 2 (ACE2) plays an important role in the development of essential hypertension (EH). The aim of this study was to investigate the relationship of ACE2 gene polymorphisms and enzymatic activity with EH in the northeastern Chinese Han population. 34 single-nucleotide polymorphism (SNP) loci of ACE2 were detected in 1024 EH patients and 956 normotensive (NT) controls by Sequenom Mass-ARRAY RS1000. Five SNPs (rs1514283, rs4646155, rs4646176, rs2285666, and rs879922) in ACE2 gene were determined to significantly associate with EH in female participants, while no SNP locus was linked to male group. Specifically, it was the first time to report that rs4646155 was significantly associated with EH in females. Furthermore, the correlation between ACE2 activity and clinical parameters were performed by Pearson correlation analysis in EH patients. We found that the ACE2 activity level was negatively correlated with body mass index (BMI), DBP, and pulse pressure, and significantly positively with ACE2 concentration, blood glucose and estrogen level in female EH patients. These results demonstrated that the genetic variants of ACE2 played vital roles in the development of EH. And the serum ACE2 activity can predict the development of cardiac dysfunction in EH patients.
Clinical experience with ferric carboxymaltose in the management of anemia in acute gastrointestinal bleeding
Authors: Ballester-Clau Raquel , Torres Vicente Gisela , Voltà-Pardo Tania , López-Barroso Laura , Cucala-Ramos Mercedes , Reñé-Espinet Josep M. , Planella de Rubinat Montse
Published: October 2018

Objective

The aim of this study was to assess the efficacy and safety of intravenous ferric carboxymaltose (FCM) following hospitalization for acute gastrointestinal bleeding (AGIB) in the context of a restrictive transfusion strategy.

Patients and methods

A retrospective single-center study analyzed patients with AGIB (excluding AGIB secondary to portal hypertension) administered a single FCM dose with or without blood transfusion.

Results

Eighty-six episodes in 84 patients were analyzed. Seventy-nine patients had upper AGIB. Nineteen episodes were associated with hemodynamic instability. FCM was administered during hospitalization as a single dose of 1000 mg iron in 84/86 episodes and as a single dose of 500 mg iron in two episodes, with blood transfusion in 60/86 (69.8%) episodes. The mean hemoglobin (Hb) was 9.0 g/dl at admission, 7.6 g/dl at the lowest in-hospital value, 9.4 g/dl at discharge, and 12.7 g/dl at follow-up (mean: 55 days postdischarge) (P<0.001 for follow-up vs. all other timepoints). The lowest mean in-hospital Hb value was 7.2 and 8.8 g/dl, respectively, in patients with transfusion+FCM versus FCM alone; the mean Hb was 12.4 versus 13.7 g/dl at follow-up. In patients administered FCM alone, the mean Hb at follow-up in the subpopulations aged older than or equal to 75 years (n=33), Charlson comorbidity index of at least 3 (n=48), and Hb of up to 10 g/dl at admission (n=47) were 12.6, 13.1, and 13.3 g/dl, respectively. No adverse effects were detected.

Conclusion

Treatment with FCM for AGIB is associated with a good erythropoietic response and anemia correction after hospitalization, even in severe episodes or when transfusion is needed. FCM is safe and well tolerated, and may support a restrictive transfusion policy.
Should Pediatricians Be Aware of Cystic Echinococcosis? A Literature Review
Authors: Tersigni Chiara , Venturini Elisabetta , Montagnani Carlotta , Bianchi Leila , Chiappini Elena , de Martino Maurizio , Galli Luisa
Published: October 2018

Among parasitic hepatic cystic lesions, the most common disease is represented by cystic echinococcosis (CE), especially in high endemic countries. European epidemiology of CE in children is difficult to assess because of under‐reporting but is increasing, because of high immigration flows from endemic countries and an increased awareness. Hydatidosis can be localized in every part of the body. The liver and lungs are the most common localizations in both children and adults. Multiorgan involvement is rarely reported in children. Different tests are available. Usually the sensitivity of serological screening tests is variable, ranging between 60% and 90%. The immunoblot assay is used as a confirmatory test because of its higher sensitivity and specificity. Radiological tests are the criterion standard for diagnosis of CE, with an ultrasound accuracy of approximately 90%. In case of inactive and uncomplicated cysts the watch‐and‐wait approach is recommended. Albendazole, currently used for 3 to 6 months consecutively represents the most commonly used drug in children even if there is limited experience in treating children younger than 6 years of age. Percutaneous treatment with the puncture, aspiration, injection, and reaspiration technique is a minimally invasive procedure. Surgery is indicated based on cyst characteristics in case of big cysts with multiple daughter cysts, single superficial cysts at risk of spontaneous or traumatic rupture, cysts related with the biliary tract in which the percutaneous treatment is contraindicated, and cysts compressing related structures.
Serum and Urinary Hepcidin for Diagnosing Iron-deficiency Anemia in Under-5 Children
Authors: Dewan Pooja , Dixit Anupriya , Gomber Sunil , Kotru Mrinalini , Banerjee Basu D. , Tyagi Vipin , Malhotra Rajeev K.
Published: October 2018

Bone marrow iron estimation remains the gold standard for diagnosing iron-deficiency anemia (IDA); serum ferritin, total iron-binding capacity, and transferrin saturation are routinely used as surrogate markers of IDA. However, these tests are marred by problems like poor specificity and sensitivity. Recently, hepcidin, a protein hormone synthesized in the liver and excreted in urine, has been shown to be related to iron status. We estimated the serum and urinary hepcidin levels in healthy children 6 to 60 months of age with (n=30) and without IDA (n=30). The mean (SD) serum hepcidin levels in children with IDA were significantly lower than those in children without IDA (3.03 [1.06] vs. 4.78 [3.94] ng/mL; P=0.02). The mean (SD) urinary hepcidin levels were also significantly lower in children with IDA than those in children without IDA (2.29 [0.53] vs. 2.79 [0.75] ng/mL; P=0.004). Performance of urinary and serum hepcidin compared with serum ferritin (<12 µg/L) for diagnosing IDA in terms of area under the receiver operating characteristic curve was 0.704 (P=0.007) and 0.59 (P=0.22), respectively. Serum hepcidin is not useful for diagnosing IDA in under-5 children. In contrast, urinary hepcidin holds promise as a noninvasive diagnostic tool for IDA in under-5 children.
Symptom Trajectories of Adolescents During Hematopoietic Stem Cell Recovery
Authors: Rodgers Cheryl , Highberger Marika , Powers Kimberly , Voigt Katherine , Douglas Christian
Published: October 2018

Background

Adolescents undergoing allogeneic hematopoietic stem cell transplantation (HSCT) experience multiple symptoms during and after the transplant. These symptoms can increase the need for medical care and reduce the quality of their life. However, little is known about symptom experiences specific to adolescents undergoing HSCT.

Objective

The primary aim was to describe symptom incidence, severity, and distress trajectories among adolescents from pre-HSCT through 90 days post-HSCT. A secondary aim was to examine the relationship between symptom trajectories and demographic and treatment factors.

Methods

A repeated-measures design was used for this prospective study. Demographic and treatment information was collected from the medical record. Symptoms were assessed with the Memorial Symptom Assessment Scale 10–18. Symptom trajectories were identified by latent class growth analysis with growth mixture modeling; logistic regression evaluated relationships of demographic and treatment characteristics on the latent classes of symptom trajectories.

Results

Two distinct latent class trajectories were identified for symptom incidence, severity, and distress. Symptom incidence declined, but symptom severity and distress remained stable. No significant relationships were noted among any demographic or treatment characteristics to any of the symptom trajectories.

Conclusions

Symptoms persist and remain severe and distressing throughout the first 90 days after HSCT, with pain and lack of energy among the highest in incidence, severity, and distress.

Implications for Practice

Awareness of symptom trajectories empowers nurses to assess for symptoms throughout the HSCT process and conduct meaningful symptom discussions with their patients.
Multi-modal Educational Curriculum to Improve Richmond Agitation-sedation Scale Inter-rater Reliability in Pediatric Patients
Authors: Kihlstrom Margaret J. , Edge Ashley P. , Cherry Kelly M. , Zarick Paul J. , Beck Shawna D. , Boyd Jenny M.
Published: October 2018

Introduction:

The Richmond Agitation-sedation Scale (RASS) is a reliable and valid scale for assessing sedation in critically ill pediatric patients. This investigation evaluates the inter-rater reliability of the RASS in mechanically ventilated pediatric patients before and after an educational intervention.

Methods:

This prospective, interventional quality improvement study was completed in a 20-bed pediatric intensive care unit from July 2013 to July 2014. Children 0–18 years of age requiring mechanical ventilation and receiving sedative or analgesic medications were eligible. Staff completed simultaneous paired RASS assessments in 3 phases: baseline, after educational intervention, and maintenance.

Results:

Staff completed 347 paired assessments on 45 pediatric intensive care unit patients: 49 in the baseline phase, 228 in the postintervention phase, and 70 in the maintenance phase. There was a significant increase in the weighted κ after the intervention, from 0.56 (95% CI, 0.39–0.72) to 0.86 (95% CI, 0.77–0.95; P < 0.001). The improvement was maintained months later with weighted κ 0.78 (95% CI, 0.61–0.94). In subgroup analysis, there was an increase in weighted κ in patients less than 1 year of age (0.41–0.87) and those with developmental delay (0.49–0.84).

Conclusions:

The RASS is a reliable tool for sedation assessment in mechanically ventilated, sedated pediatric patients after implementation of an educational intervention. It is also reliable in patients less than 12 months of age and patients with developmental delay. The ability to easily educate providers to utilize a valid, reliable sedation tool is an important step toward using it to provide consistent care to optimize sedation.
Improving Human Papilloma Virus Vaccination Rates at an Urban Pediatric Primary Care Center
Authors: Brodie Nicola , McPeak Katie E.
Published: October 2018

Introduction:

Despite compelling evidence regarding its safety and efficacy, human papilloma virus vaccination rates remain low nationally with high rates of missed vaccination opportunities. Provider recommendation is the most important factor in determining vaccine approval by families; yet, studies show that providers are hesitant to strongly recommend vaccination, especially at younger ages. We hypothesized that educational and quality improvement interventions targeting our clinical team would decrease rates of missed opportunities to vaccinate patients aged 11–13 years and improve vaccination rates among patients aged 9–10 years old.

Methods:

This quality improvement project took place at an urban, academic pediatric primary care center in north Philadelphia, which serves as the medical home for over 22,000 patients. A multidisciplinary team performed a series of planned sequential interventions to improve human papilloma virus vaccination rates. The electronic health records of children aged 9–13 who presented to our center from September 2014 through December 2015 were queried. Statistical process control charts and established rules for detecting special cause variation were applied.

Results:

Rates of missed opportunities to vaccinate 11- to 13-year-old patients decreased from 63% to 18% during the intervention period. Rates of immunization of 9- to 10-year-old patients increased from 56% to 84% during the intervention period.

Conclusion:

This low-cost, multifaceted, interdisciplinary quality improvement project resulted in a decrease in missed opportunities to vaccinate among children aged 11–13 years old and improved the vaccination rates of 9–10 year olds. Ongoing interventions are needed to sustain these efforts and to ensure timely vaccine series completion.
“Learn From Every Patient”: How a Learning Health System Can Improve Patient Care
Authors: Noritz Garey , Boggs Adam , Lowes Linda P. , Smoyer William E.
Published: October 2018

Aim:

We created a Learning Health System, the “Learn From Every Patient” program, embedded in our cerebral palsy team clinic. This program was designed to simultaneously provide clinical care while systematically collecting data for quality improvement and research projects on all patients.

Method:

Clinicians created tools within the Electronic Health Record to discretely capture data for clinical use which was also available for quality improvement/research efforts. At baseline, all patients in our clinic received annual hip x-rays to screen for hip displacement. Using our “Learn From Every Patient” database, we reviewed the outcomes for the most mildly affected patients, Level I on the Gross Motor Functional Classification System.

Results:

One hundred thirty-two patients were classified as Gross Motor Functional Classification System Level I. During the study period, these patients received 212 pelvis x-rays, viewing 424 hips, of which 419 (98.8%) were normal. Five hips (1.2%) had < 30% displacement. None had any hip-related symptoms nor required any procedures during the period. We used these data to create an evidence-based change in our standardized hip screening procedure by eliminating annual screening x-rays for this population.

Interpretation:

This implementation of a local learning health system approach to systematically collect research data simultaneously with routine clinical care enabled us to implement an evidence-based improvement in clinical practice. This complete integration of research into clinical care improved care by reducing radiation exposure, while simultaneously reducing health care costs.
Evaluating Interventions to Increase Influenza Vaccination Rates among Pediatric Inpatients
Authors: Rao Suchitra , Fischman Victoria , Kaplan David W. , Wilson Karen M. , Hyman Daniel
Published: October 2018

Introduction:

Hospitalization provides an ideal opportunity for influenza vaccination, and strategies can enhance existing tools within the electronic medical record (EMR). The objectives of the study were to introduce and evaluate the effectiveness of provider and family-directed interventions to increase influenza vaccination ordering among inpatients.

Methods:

We conducted a quality improvement initiative for children aged older than 6 months on medical inpatient teams at a large pediatric tertiary care hospital from September 2014 to March 2015, comprising 2 intervention groups (provider reminders and family education) and 1 control group for comparison, using EMR prompts alone. The provider reminder interventions comprised weekly e-mails indicating inpatient immunization status; vaccination reports; and visual reminders. The family education group intervention consisted of handouts regarding the benefits and safety of influenza vaccination. We measured vaccine ordering rates for each group among eligible children and overall vaccination rates. Data were analyzed using Statistical Process Control Charts and Chi-square tests.

Results:

Among 2,552 patients aged older than 6 months hospitalized during the study period, 1,657 were unimmunized. During the intervention period, the provider group ordered 213/409 (52%) influenza vaccines, the family education group ordered 138/460 (30%) and the control group ordered 71/279 (25%) (P < 0.0001). The provider group had higher influenza immunization status than the control group (61% versus 53%; P = 0.0017). Exposure to the intervention did not impact the length of stay/discharge time.

Conclusions:

Provider reminders including e-mails, visual reminders, and vaccination reports are effective ways of increasing inpatient influenza vaccination rates and are more effective than family education, or EMR prompts alone.
Decreasing Blood Culture Contaminants in a Pediatric Emergency Department: An Interrupted Time Series Analysis
Authors: Mullan Paul C. , Scott Sara , Chamberlain James M. , Pettinichi Jeanne , Palacious Katura , Weber Anastasia , Payne Asha S. , Badolato Gia M. , Brown Kathleen
Published: October 2018

Introduction:

High peripheral blood culture contamination rates (BCCR) in the emergency department (ED) contribute to overuse and harm. This study describes 2 years of quality improvement (QI) interventions that aimed to decrease a high BCCR in a pediatric ED.

Methods:

The QI team created a Key Driver Diagram with multiple Plan-Do-Study-Act (PDSA) cycles. PDSA interventions included a venipuncture sterility checklist (PDSA1), phlebotomist feedback system (PDSA2), and physician ordering guidelines (PDSA3). The specific aim was to decrease the BCCR by 50% within 24 months. The secondary aim was to decrease the peripheral blood culture ordering rate (BCOR) by 10% within 24 months. The balancing measure was the proportion of pathogenic bacteremia cases at ED return visits before and after PDSA3 implementation. A financial measure estimated the savings in charges between the observed and expected contaminants in PDSA3. An interrupted time series design applied statistical process control methodology to detect special cause variations.

Results:

The BCCR in the baseline, PDSA1, PDSA2, and PDSA3 periods were 3.02%, 2.30%, 1.58%, and 1.17%, respectively. The BCOR in the baseline, PDSA1, PDSA2, and PDSA3 periods was 4.80%, 4.26%, 3.82%, and 3.49%, respectively. Special cause variations occurred after PDSA cycle implementations for both BCCR and BCOR. There was no change in the balancing measure. The interventions were associated with an annual prevention of 95 contaminants and savings of $300,070.

Conclusions:

Interventions that focused on improving venipuncture technique and limiting unnecessary blood cultures were associated with fewer contaminants and the achievement of the QI team’s project aims.
Decreasing Unexpected Returns to Orthopedic Hand Clinic: Improving Efficiency of Health Care Delivery
Authors: Little Kevin J. , Trehan Samir , Cornwall Roger , Garrison Stephanie , Dastillung Emily , McFadden Lisa
Published: October 2018

Purpose:

An unexpected return to clinic (URTC) visit can place a substantial financial burden on patients and families while stressing the health care system. Our SMART aim was to decrease the rate of URTC visits from 1.8 per 100 patient follow-up visits by 50% using quality improvement methodology.

Methods:

The rate of URTC visits was tracked at our tertiary care pediatric hospital from February 1, 2014, to May 31, 2015, using a weekly P-chart. Interventions were studied from January 1 to May 31, 2015. Pareto charts determined the common causes of URTC visits. Interventions were studied using Plan-Do-Study-Act cycles. Medical charges for URTC patient visits were collected and patients/families were given a cost survey to determine nonmedical costs associated with the clinic visits.

Results:

Cast issues (50.5%) were most common, followed by new symptom/complaints (29.5%), and persistent or worse symptoms (15.2%). Following interventions, URTC rates decreased from 1.8 to 0.7 (⇓62%) per 100 follow-up visits during the study period. Interventions were targeted toward cast use and improved patient education via standardized materials. The average URTC resulted in $350.38 of charges. Additionally, the average URTC cost families $70 for a half day of lost wages and travel expenses.

Discussion:

Applying quality improvement methodology to URTC visits by standardizing patient education and minimizing cast usage resulted in a substantial decrease in the number of patients returning to clinic, both for scheduled follow-ups and unexpectedly. This improvement resulted in a savings of more than $420 per visit saved, including medical and nonmedical costs.
Third-Line Antiretroviral Therapy Program in the South African Public Sector: Cohort Description and Virological Outcomes
Authors: Moorhouse Michelle , Maartens Gary , Venter Willem Daniel Francois , Moosa Mahomed-Yunus , Steegen Kim , Jamaloodien Khadija , Fox Matthew P. , Conradie Francesca
Published: October 2018

Background:

The World Health Organization recommends that antiretroviral therapy (ART) programs in resource-limited settings develop third-line ART policies. South Africa developed a national third-line ART program for patients who have failed both first-line non-nucleoside reverse transcriptase inhibitor–based ART and second-line protease inhibitor (PI)-based ART. We report on this program.

Methods:

Third-line ART in South Africa is accessed through a national committee that assesses eligibility and makes individual regimen recommendations. Criteria for third-line include the following: ≥1 year on PI-based ART with virologic failure, despite adherence optimization, and genotypic antiretroviral resistance test showing PI resistance. We describe baseline characteristics and resistance patterns of this cohort and present longitudinal data on virological suppression rates.

Results:

Between August 2013 and July 2014, 144 patients were approved for third-line ART. Median age was 41 years [interquartile range (IQR): 19–47]; 60% were women (N = 85). Median CD4+ count and viral load were 172 (IQR: 128–351) and 14,759 (IQR: 314–90,378), respectively. About 2.8% started PI-based ART before 2004; 11.1% from 2004 to 2007; 31.3% from 2008 to 2011; and 6.3% from 2012 to 2014 (48.6% unknown start date). Of the 144 patients, 97% and 98% had resistance to lopinavir and atazanavir, respectively; 57% had resistance to darunavir. All were initiated on a regimen containing darunavir, with raltegravir in 101, and etravirine in 33. Among those with at least 1 viral load at least 6 months after third-line approval (n = 118), a large proportion (83%, n = 98) suppressed to <1000 copies per milliliter, and 79% (n = 93) to <400 copies per milliliter.

Conclusion:

A high proportion of third-line patients with follow-up viral loads are virologically suppressed.
Unilateral Chronic Lung Allograft Dysfunction Assessed by Biphasic Computed Tomographic Volumetry in Bilateral Living-donor Lobar Lung Transplantation
Authors: Saito Masao , Chen-Yoshikawa Toyofumi F. , Nakamoto Yuji , Kayawake Hidenao , Tokuno Junko , Ueda Satoshi , Yamagishi Hiroya , Gochi Fumiaki , Okabe Ryo , Takahagi Akihiro , Hamaji Masatsugu , Motoyama Hideki , Aoyama Akihiro , Date Hiroshi
Published: October 2018

Background

Early diagnosis of unilateral chronic lung allograft dysfunction (CLAD) is difficult because the unaffected contralateral lung functions as a reservoir in bilateral living-donor lobar lung transplantation (LDLLT). We previously reported the usefulness of 133Xe ventilation scintigraphy for detection of unilateral change, but the supply of 133Xe has been stopped globally. The present study aimed to examine the usefulness of inspiratory and expiratory computed tomography (I/E CT) volumetry for detection of unilateral change in CLAD patients.

Methods

This was a retrospective single-center, observational study using prospectively collected data. A total of 58 patients who underwent bilateral LDLLT from August 2008 to February 2017 were analyzed. Respiratory function tests, I/E CT were prospectively conducted. ΔLung volume was defined as the value obtained by subtracting expiratory lung volume from inspiratory lung volume.

Results

Fourteen (24%) cases were clinically diagnosed with CLAD, of which 10 (71%) were diagnosed as unilateral CLAD. ΔLung volume of bilateral lungs strongly correlated with forced vital capacity (r = 0.92, P < 0.01) and forced expiratory volume in 1 second (r = 0.80, P < 0.01). Regardless the phenotypes (bronchiolitis obliterans syndrome or restrictive allograft syndrome) of CLAD, Δlung volume onset/baseline significantly decreased compared with that in the non-CLAD group. Among the 10 unilateral CLAD patients, 3 with clinically suspected unilateral rejection yet did not show a 20% decline in forced expiratory volume in 1 second. In 2 of these, Δlung volume of unilateral lungs on the rejection side decreased by 20% or more.

Conclusions

Our findings suggest that I/E CT volumetry may be useful for assessment and early diagnosis of unilateral CLAD after bilateral LDLLT.
Water-repellent plant surface structure induced by gall-forming insects for waste management
Authors: Uematsu Keigo , Kutsukake Mayako , Fukatsu Takema
Published: October 2018

Many animals and plants have evolved elaborate water-repellent microstructures on their surface, which often play important roles in their ecological adaptation. Here, we report a unique type of water-repellent structure on a plant surface, which develops as an insect-induced plant morphology in a social context. Some social aphids form galls on their host plant, in which they produce large amounts of hydrophobic wax. Excreted honeydew is coated by the powdery wax to form ‘honeydew balls’, which are actively disposed by soldier nymphs through an opening on their gall. These activities are enabled by a highly water-repellent inner gall surface, and we discovered that this surface is covered with dense trichomes that are not found on normal plant surfaces. The trichomes are coated by fine particles of the insect-produced wax, thereby realizing a high water repellency with a cooperative interaction between aphids and plants. The plant leaves on which the gall is formed often exhibit patchy areas with dense trichomes, representing an ectopic expression of the insect-induced plant morphology. In the pouch-shaped closed galls of a related social aphid species, by contrast, the inner surface was not covered with trichomes. Our findings provide a convincing example of how the extended phenotype of an animal, expressed in a plant, plays a pivotal role in maintaining sociality.
Learning from others: an invasive lizard uses social information from both conspecifics and heterospecifics
Authors: Damas-Moreira Isabel , Oliveira Daniel , Santos Joana L. , Riley Julia L. , Harris D. James , Whiting Martin J.
Published: October 2018

Species that are able to solve novel problems through social learning from either a conspecific or a heterospecific may gain a significant advantage in new environments. We tested the ability of a highly successful invasive species, the Italian wall lizard
Podarcis sicula
, to solve a novel foraging task when social information was available from both a conspecific and an unfamiliar heterospecific (
Podarcis bocagei
). We found that Italian wall lizards that had access to social information made fewer errors, regardless of whether the demonstrator was a conspecific or a heterospecific, compared to Italian wall lizards that individually learnt the same task. We suggest that social learning could be a previously underappreciated, advantageous mechanism facilitating invasions.
Rates of population differentiation and speciation are decoupled in sea snakes
Authors: Nitschke Charlotte R. , Hourston Mathew , Udyawer Vinay , Sanders Kate L.
Published: October 2018

Comparative phylogeography can inform many macroevolutionary questions, such as whether species diversification is limited by rates of geographical population differentiation. We examined the link between population genetic structure and species diversification in the fully aquatic sea snakes (Hydrophiinae) by comparing mitochondrial phylogeography across northern Australia in 16 species from two closely related clades that show contrasting diversification dynamics. Contrary to expectations from theory and several empirical studies, our results show that, at the geographical scale studied here, rates of population differentiation and speciation are not positively linked in sea snakes. The eight species sampled from the rapidly speciating
Hydrophis
clade have weak population differentiation that lacks geographical structure. By contrast, all eight sampled
Aipysurus–Emydocephalus
species show clear geographical patterns and many deep intraspecific splits, but have threefold slower speciation rates. Alternative factors, such as ecological specialization, species duration and geographical range size, may underlie rapid speciation in sea snakes.
The effect of polyaspartate chain length on mediating biomimetic remineralization of collagenous tissues
Authors: Quan Bryan D. , Sone Eli D.
Published: October 2018

Formation of hydroxyapatite (HAP) within collagen fibrils, as found in bone, dentine and cementum, is thought to be mediated by proteins rich in aspartate (Asp) and glutamate such as osteopontin and bone sialoprotein, respectively. Indeed polyaspartate (pAsp), a homopolymer analogue of such proteins, has been shown to induce intrafibrillar mineralization of collagen from solutions of calcium and phosphate that are supersaturated with respect to HAP. To elucidate the role of pAsp in mineralization of collagen, we explored the effect of pAsp chain length onin vitroHAP deposition in demineralized mouse periodontal tissue sections. Through characterization of both tissue sections and mineralizing solution, we show that chain length contributes to the effectiveness of pAsp in mediating intrafibrillar mineralization. This function appears to be associated with inhibition of otherwise kinetically favoured crystallization in the bulk solution, which allows for intrafibrillar crystallization, though this does not preclude the possibility of a more active role for pAsp in addition. Inhibition of crystallization in solution by pAsp occurs by slowing the growth of amorphous calcium phosphate and stabilization of this phase, rather than by sequestration of Ca2+ions. These results suggest that the length of Asp-rich sequences of mineralizing proteins may be essential to their function, and could also be useful in optimization of mineralized tissue replacement synthesis.
Dielectric characterization of
Plasmodium falciparum
-infected red blood cells using microfluidic impedance cytometry
Authors: Honrado C. , Ciuffreda L. , Spencer D. , Ranford-Cartwright L. , Morgan H.
Published: October 2018

Although malaria is the world's most life-threatening parasitic disease, there is no clear understanding of how certain biophysical properties of infected cells change during the malaria infection cycle. In this article, we use microfluidic impedance cytometry to measure the dielectric properties of
Plasmodium falciparum
-infected red blood cells (
i-
RBCs) at specific time points during the infection cycle. Individual parasites were identified within
i-
RBCs using green fluorescent protein (GFP) emission. The dielectric properties of cell sub-populations were determined using the multi-shell model. Analysis showed that the membrane capacitance and cytoplasmic conductivity of
i-
RBCs increased along the infection time course, due to membrane alterations caused by parasite infection. The volume ratio occupied by the parasite was estimated to vary from less than 10% at earlier stages, to approximately 90% at later stages. This knowledge could be used to develop new label-free cell sorting techniques for sample pre-enrichment, improving diagnosis.
Fire spread and the issue of community-level selection in the evolution of flammability
Authors: Schertzer Emmanuel , Staver A. Carla
Published: October 2018

Whether plants can evolve to promote flammability is controversial. Ecologically, fire only spreads in landscapes when many plants are flammable, but collective behaviours among large groups are difficult to evolve at the individual level. Here, we formulate a model that examines how flammability can spread from rarity, combining individual-level costs and payoffs of flammability with landscape-level fire spread, sufficiently generic to analogize flammability among grasses, Mediterranean systems, and others. We found that fire-prone and fire-suppressing landscapes, composed of flammable and non-flammable plants, respectively, were alternatively stable in some environments, and flammability therefore only increased from rarity in environments when fire-proneness was the only stable state. Thus, fire–vegetation feedbacks alone probably did not drive the evolution and spread of flammability. However, evolution of flammability did promote fire-proneness in temporally and spatially heterogeneous environments: when flammable plants already occupied some substantial fraction of a fire-prone landscape, a positive feedback with fire could maintain flammability in a decreasingly favourable environment, and fire feedbacks could expand the distribution of flammability traits from fire-prone into fire-suppressing areas in a heterogeneous landscape. Thus, fire feedbacks could potentially have promoted the widespread invasion and persistence of flammability traits to their current widespread prominence.
Interception by two predatory fly species is explained by a proportional navigation feedback controller
Authors: Fabian Samuel T. , Sumner Mary E. , Wardill Trevor J. , Rossoni Sergio , Gonzalez-Bellido Paloma T.
Published: October 2018

When aiming to capture a fast-moving target, animals can follow it until they catch up, or try to intercept it. In principle, interception is the more complicated strategy, but also more energy efficient. To study whether simple feedback controllers can explain interception behaviours by animals with miniature brains, we have reconstructed and studied the predatory flights of the robber flyHolcocephala fuscaand killer flyCoenosia attenuata. Although both species catch other aerial arthropods out of the air,Holcocephalacontrasts prey against the open sky, whileCoenosiahunts against clutter and at much closer range. Thus, their solutions to this target catching task may differ significantly. We reconstructed in three dimensions the flight trajectories of these two species and those of the presented targets they were attempting to intercept. We then tested their recorded performances against simulations. We found that both species intercept targets on near time-optimal courses. To investigate the guidance laws that could underlie this behaviour, we tested three alternative control systems (pure pursuit, deviated pursuit and proportional navigation). Only proportional navigation explains the timing and magnitude of fly steering responses, but with differing gain constants and delays for each fly species.Holcocephalauses a dimensionless navigational constant ofN≈ 3 with a time delay of ≈28 ms to intercept targets over a comparatively long range. This constant is optimal, as it minimizes the control effort required to hit the target. In contrast,Coenosiauses a constant ofN≈ 1.5 with a time delay of ≈18 ms, this setting may allowCoenosiato cope with the extremely high line-of-sight rotation rates, which are due to close target proximity, and thus prevent overcompensation of steering. This is the first clear evidence of interception supported by proportional navigation in insects. This work also demonstrates how by setting different gains and delays, the same simple feedback controller can yield the necessary performance in two different environments.
Stable formations of self-propelled fish-like swimmers induced by hydrodynamic interactions
Authors: Dai Longzhen , He Guowei , Zhang Xiang , Zhang Xing
Published: October 2018

Fish schools are fascinating examples of macro-scale systems with collective behaviours. According to conventional wisdom, the establishment and maintenance of fish schools probably need very elaborate active control mechanisms. Sir James Lighthill posited that the orderly formations in fish schools may be an emergent feature of the system as a result of passive hydrodynamic interactions. Here, numerical simulations are performed to test Lighthill’s conjecture by studying the self-propelled locomotion of two, three and four fish-like swimmers. We report the emergent stable formations for a variety of configurations and examine the energy efficiency of each formation. The result of this work suggests that the presence of passive hydrodynamic interactions can significantly mitigate the control challenges in schooling. Moreover, our finding regarding energy efficiency also challenges the widespread idea in the fluid mechanics community that the diamond-shaped array is the most optimized pattern.
Micromechanics of elastic lamellae: unravelling the role of structural inhomogeneity in multi-scale arterial mechanics
Authors: Yu Xunjie , Turcotte Raphaël , Seta Francesca , Zhang Yanhang
Published: October 2018

Microstructural deformation of elastic lamellae plays important roles in maintaining arterial tissue homeostasis and regulating vascular smooth muscle cell fate. Our study unravels the underlying microstructural origin that enables elastic lamellar layers to evenly distribute the stresses through the arterial wall caused by intraluminal distending pressure, a fundamental requirement for tissue and cellular function. A new experimental approach was developed to quantify the spatial organization and unfolding of elastic lamellar layers under pressurization in mouse carotid arteries by coupling physiological extension–inflation and multiphoton imaging. Tissue-level circumferential stretch was obtained from analysis of the deformation of a thick-walled cylinder. Our results show that the unfolding and extension of lamellar layers contribute simultaneously to tissue-level deformation. The inner lamellar layers are wavier and unfold more than the outer layers. This waviness gradient compensates the larger tissue circumferential stretch experienced at the inner surface, thus equalizing lamellar layer extension through the arterial wall. Discoveries from this study reveal the importance of structural inhomogeneity in maintaining tissue homeostasis through the arterial wall, and may have profound implications on vascular remodelling in aging and diseases, as well as in tissue engineering of functional blood vessels.
Bacterial chromosome organization by collective dynamics of SMC condensins
Authors: Miermans Christiaan A. , Broedersz Chase P.
Published: October 2018

A prominent organizational feature of bacterial chromosomes was revealed by Hi-C experiments, indicating anomalously high contacts between the left and right chromosomal arms. These long-range contacts have been attributed to various nucleoid-associated proteins, including the ATPase Structural Maintenance of Chromosomes (SMC) condensin. Although the molecular structure of these ATPases has been mapped in detail, it still remains unclear by which physical mechanisms they collectively generate long-range chromosomal contacts. Here, we develop a computational model that captures the subtle interplay between molecular-scale activity of slip-links and large-scale chromosome organization. We first consider a scenario in which the ATPase activity of slip-links regulates their DNA-recruitment near the origin of replication, while the slip-link dynamics is assumed to be diffusive. We find that such diffusive slip-links can collectively organize the entire chromosome into a state with aligned arms, but not within physiological constraints. However, slip-links that include motor activity are far more effective at organizing the entire chromosome over all length-scales. The persistence of motor slip-links at physiological densities can generate large, nested loops and drive them into the bulk of the DNA. Finally, our model with motor slip-links can quantitatively account for the rapid arm–arm alignment of chromosomal arms observed
in vivo
.
Analysis and demonstration: Wallis and Newton on mathematical presentation
Authors: Kaplan Abram
Published: October 2018

Emulating the Greek geometers, Newton used synthetic demonstration to present the ground-breaking arguments of the
Principia
. This paper argues that we can better understand Newton's reasons for using geometry by considering John Wallis's interpretation of synthetic demonstration. Wallis condemned demonstration for failing to explain the mathematical truths it presented. He opposed to it a presentation that combined symbolic analysis with a documented account of discovery. In preferring symbols, Wallis was motivated both by the nascent tradition of symbolic analysis and by contemporary interest in artificial languages. Newton maintained Wallis's characterization of Greek demonstration as adapted to common understanding rather than as strictly elucidating, but he inverted the values Wallis associated with synthesis and analysis. In Newton's new account, synthetic demonstration was preferable precisely because it could address inexpert readers without exposing them to the complications of symbols-based analysis. Newton advanced his arguments on behalf of geometry through portraits of ancient mathematicians: Archimedes and Pythagoras.
Follow the data: administering science at Edward Sabine's magnetic department, Woolwich, 1841–57
Authors: Goodman Matthew
Published: October 2018

This paper considers the transmission of magnetic observations from overseas, colonial, observatories and the removal of these data from manuscripts to become the printed results of the so-called magnetic crusade, between 1841 and 1857. The processes adopted by Edward Sabine's magnetic department at Woolwich Arsenal to cope with the accumulation of very literal masses of data are considered, as well as the politicking that attended Sabine's attempts to have this department installed within the space occupied by, and the bureaucracy of, the Board of Ordnance. The magnetic crusade was one of the largest data-collecting enterprises of the nineteenth century, and a history of its data-management processes provides an important contribution to recent attempts to historicize discussions about Big Data and perceptions of information overload.
Mad1 influences interphase nucleoplasm organization and chromatin regulation inDrosophila
Authors: Raich Natacha , Mahmoudi Souhir , Emre Doruk , Karess Roger E.
Published: October 2018

TheDrosophilaMad1 spindle checkpoint protein helps organize several nucleoplasmic components, and flies lacking Mad1 present changes in gene expression reflecting altered chromatin conformation. In interphase, checkpoint protein Mad1 is usually described as localizing to the inner nuclear envelope by binding the nucleoporin Tpr, an interaction believed to contribute to proper mitotic regulation. Whether Mad1 has other nuclear interphase functions is unknown. We found inDrosophilathat Mad1 is present in nuclei of both mitotic and postmitotic tissues. Three proteins implicated in various aspects of chromatin organization co-immunoprecipitated with Mad1 from fly embryos: Mtor/Tpr, the SUMO peptidase Ulp1 and Raf2, a subunit of a Polycomb-like complex. In primary spermatocytes, all four proteins colocalized in a previously undescribed chromatin-associated structure called here a MINT (Mad1-containing IntraNuclear Territory). MINT integrity required all four proteins. Inmad1mutant spermatocytes, the other proteins were no longer confined to chromatin domains but instead dispersed throughout the nucleoplasm.mad1flies also presented phenotypes indicative of excessive chromatin of heterochromatic character during development of somatic tissues. Together these results suggest thatDrosophilaMad1, by helping organize its interphase protein partners in the nucleoplasm, contributes to proper chromatin regulation.
Cross-cultural differences in implicit learning of chunks versus symmetries
Authors: Ling Xiaoli , Zheng Li , Guo Xiuyan , Li Shouxin , Song Shiyu , Sun Lining , Dienes Zoltan
Published: October 2018

Three experiments explore whether knowledge of grammars defining global versus local regularities has an advantage in implicit acquisition and whether this advantage is affected by cultural differences. Participants were asked to listen to and memorize a number of strings of 10 syllables instantiating an inversion (i.e. a global pattern); after the training phase, they were required to judge whether new strings were well formed. In Experiment 1, Western people implicitly acquired the inversion rule defined over the Chinese tones in a similar way as Chinese participants when alternative structures (specifically, chunking and repetition structures) were controlled. In Experiments 2 and 3, we directly pitted knowledge of the inversion (global) against chunk (local) knowledge, and found that Chinese participants had a striking global advantage in implicit learning, which was greater than that of Western participants. Taken together, we show for the first time cross-cultural differences in the type of regularities implicitly acquired.
The sintering kinetics of shellfish porcelain reinforced by sepiolite nanofibres
Authors: Tian Li , Wang Lijuan , Wang Kailei , Zhang Yuedan , Liang Jinsheng , Zhang Yi
Published: October 2018

The work investigated the effect of sepiolite nanofibres on mechanical properties and sintering behaviour of shellfish porcelain. Samples of shellfish porcelain reinforced by sepiolite nanofibres were fired in an electric furnace at 1150, 1200 and 1250°C for a period of 80, 100, 120 and 140 min. Sintered samples were characterized by flexural strength, fracture toughness, scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The results showed that 2 wt% sepiolite nanofibres could increase the flexural strength and fracture toughness of the porcelain bodies through the fibre pullout and the weak interface mechanisms. Sintering activation energies were determined according to the linear shrinkage results. It is found that the liquid-phase sintering mechanism of shellfish porcelain with sepiolite nanofibres is a diffusion mechanism. Porcelain without sepiolite is controlled by volume diffusion, and eventually, the grain boundary diffusion began to appear with the increase of sepiolite addition.