bluuebunny/crossref_metadata_2025 huggingface dataset:
Endosymbiosis and its implications for evolutionary theory
Authors: O’Malley Maureen A.
Published: April 2015

Historically, conceptualizations of symbiosis and endosymbiosis have been pitted against Darwinian or neo-Darwinian evolutionary theory. In more recent times, Lynn Margulis has argued vigorously along these lines. However, there are only shallow grounds for finding Darwinian concepts or population genetic theory incompatible with endosymbiosis. But is population genetics sufficiently explanatory of endosymbiosis and its role in evolution? Population genetics “follows” genes, is replication-centric, and is concerned with vertically consistent genetic lineages. It may also have explanatory limitations with regard to macroevolution. Even so, asking whether population genetics explains endosymbiosis may have the question the wrong way around. We should instead be asking how explanatory of evolution endosymbiosis is, and exactly which features of evolution it might be explaining. This paper will discuss how metabolic innovations associated with endosymbioses can drive evolution and thus provide an explanatory account of important episodes in the history of life. Metabolic explanations are both proximate and ultimate, in the same way genetic explanations are. Endosymbioses, therefore, point evolutionary biology toward an important dimension of evolutionary explanation.
Aquaporins in developing rice grains
Authors: Hayashi Hidehiro , Ishikawa-Sakurai Junko , Murai-Hatano Mari , Ahamed Arifa , Uemura Matsuo
Published: April 2015

During rice grain filling, grain moisture content and weight show dynamic changes. We focused on the expression of all 33 rice aquaporins in developing grains. Only two aquaporin genes, OsPIP2;1 and OsTIP3;1, were highly expressed in the period 10–25 days after heading (DAH). High-temperature treatment from 7 to 21 DAH abolished the dynamic up-regulation of OsPIP2;1 in the period 15–20 DAH, whereas OsTIP3;1 expression was not affected. Immunohistochemical analysis revealed that OsPIP2;1 was present in the starchy endosperm, nucellar projection, nucellar epidermis, and dorsal vascular bundles, but not in the aleurone layer. OsTIP3;1 was present in the aleurone layer and starchy endosperm. Water transport activity of recombinant OsTIP3;1 was low, in contrast to the high activity of recombinant OsPIP2;1 we reported previously. Our data suggest that OsPIP2;1 and OsTIP3;1 have distinct roles in developing grains.
Central Venous Line Complications with Chronic Ambulatory Infusion of Prostacyclin Analogues in Pediatric Patients with Pulmonary Arterial Hypertension
Authors: Marr Courtney R. , McSweeney Julia E. , Mullen Mary P. , Kulik Thomas J.
Published: April 2015

Chronic infusion of prostacyclin (PGI2) via a Broviac central venous line (CVL) is attended by risk of CVL‐related complications, but we know of only one report regarding CVL‐associated bloodstream infection (BSI) with PGI2 in children and none regarding other complications. We conducted a retrospective cohort study involving pediatric patients with pulmonary hypertension treated with chronic intravenous infusion of PGI2 at Boston Children's Hospital and determined the rate (per 1,000 line‐days) of various CVL‐related complications. We also determined how often complications necessitated line replacement and hospitalization, time to replacement of CVLs, and interpatient variability in the incidence of complications. From 1999 until 2014, 26 patients meeting follow‐up criteria had PGI2 infusion, representing 43,855 line‐days; mean follow‐up was 56 months (range, 1.4–161 months). The CVL complication rates (per 1,000 line‐days) were as follows: CVL‐BSI, 0.25; superficial line infection, 0.48; impaired integrity, 0.59; occlusion, 0.09; and malposition, 0.32. The total complication rate was 1.73 cases per 1,000 line‐days. All CVL‐BSI and malposition cases were treated with CVL removal and replacement. Of CVLs with impaired integrity, 23 could be repaired and 3 required replacement. Six of 21 superficial CVL infections required replacement of the CVL. Three of 4 occluded CVLs were replaced. CVL complications occasioned 65 hospitalizations. There was marked interpatient variability in the rate of complications, much but not all of which appeared to be related to duration of CVL placement. We conclude that non‐BSI complications are very significant and that efforts to teach and emphasize other aspects of line care are therefore very important.
Lack of a significant pharmacokinetic interaction between maraviroc and tacrolimus in allogeneic HSCT recipients
Authors: Ganetsky Alex , Miano Todd A. , Hughes Mitchell E. , Vonderheide Robert H. , Porter David L. , Reshef Ran
Published: April 2015

Objectives

Emerging data suggest that the combination of tacrolimus and the CCR5 antagonist maraviroc, both cytochrome P450-3A4 substrates, may be effective in preventing graft-versus-host disease in patients undergoing allogeneic HSCT. This study evaluated whether a pharmacokinetic interaction exists between these agents.

Methods

The study included 36 allogeneic HSCT recipients who received maraviroc + tacrolimus and 43 recipients of tacrolimus alone. We used a difference-in-differences analysis to examine the change in the concentration/dose ratios of tacrolimus after the discontinuation of maraviroc. In addition, we analysed the concentrations and dose requirements of tacrolimus in the two groups.

Results

There was no significant difference in tacrolimus concentration/dose ratios in patients receiving maraviroc + tacrolimus compared with tacrolimus alone. Upon discontinuation of maraviroc, the change in concentration/dose ratio was small and not significant relative to the control group, and the effect estimate was further attenuated after adjustment for confounders [−0.35 (ng/mL)/(mg/day); P = 0.46]. In addition, the change in mean tacrolimus dose after discontinuation of maraviroc was similar between the groups (0.12 mg/day; P = 0.56), as was the change in mean tacrolimus concentration (0.02 ng/mL; P = 0.97).

Conclusions

Our findings do not support a significant inhibitory effect of maraviroc on the metabolism of tacrolimus. These data demonstrate that this drug combination is safe and imply that the protective effect of maraviroc against graft-versus-host disease was not mediated through an increase in tacrolimus concentrations. These findings are important for the design of clinical trials that evaluate maraviroc in combination with cytochrome P450-3A4 substrates.
Antibiotic prescribing and expenditures in outpatient paediatrics in Greece, 2010–13
Authors: Kourlaba Georgia , Kourkouni Eleni , Spyridis Nikos , Gerber Jeffrey S. , Kopsidas John , Mougkou Katerina , Lourida Athanasia , Zaoutis Theoklis E.
Published: April 2015

Objectives

The objectives of this study were to provide a nationally representative analysis of antibiotic prescribing in outpatient paediatrics and to assess overall and class-specific antibiotic costs in Greece.

Methods

Data on antibiotic prescriptions for patients aged ≤19 years old between July 2010 and June 2013 in Greece were extracted from the IMS Health Xponent database. Antibiotics were grouped into narrow- and broad-spectrum agents. The number of prescribed antibiotics and census denominators were used to calculate prescribing rates. The total costs associated with prescribed antibiotics were calculated.

Results

More than 7 million antibiotics were prescribed during the study period, with an annual rate of 1100 antibiotics/1000 persons. Prescribing rates were higher among children aged <10 years old. Acute respiratory tract infections (ARTIs) accounted for 80% of prescribed antibiotics, with acute otitis media (22.3%), acute tonsillitis (19.5%) and acute bronchitis/bronchiolitis (13.9%) being the most common clinical diagnoses. Cephalosporins (32.9%), penicillins (32.3%) and macrolides (32.1%) were the most commonly prescribed antibiotic classes. The majority (90.4%) of antibiotics were broad spectrum. Antibiotic expenditures totalled ∼€50 million.

Conclusions

Broad-spectrum antibiotic prescribing is common in outpatient paediatric patients. These data provide important targets to inform the development of an outpatient antimicrobial stewardship programme targeting specific practices, providers and conditions.
Solving the interoperability challenge of a distributed complex patient guidance system: a data integrator based on HL7’s Virtual Medical Record standard
Authors: Marcos Carlos , González-Ferrer Arturo , Peleg Mor , Cavero Carlos
Published: April 2015

Objective We show how the HL7 Virtual Medical Record (vMR) standard can be used to design and implement a data integrator (DI) component that collects patient information from heterogeneous sources and stores it into a personal health record, from which it can then retrieve data. Our working hypothesis is that the HL7 vMR standard in its release 1 version can properly capture the semantics needed to drive evidence-based clinical decision support systems.

Materials and Methods To achieve seamless communication between the personal health record and heterogeneous data consumers, we used a three-pronged approach. First, the choice of the HL7 vMR as a message model for all components accompanied by the use of medical vocabularies eases their semantic interoperability. Second, the DI follows a service-oriented approach to provide access to system components. Third, an XML database provides the data layer.

Results The DI supports requirements of a guideline-based clinical decision support system implemented in two clinical domains and settings, ensuring reliable and secure access, high performance, and simplicity of integration, while complying with standards for the storage and processing of patient information needed for decision support and analytics. This was tested within the framework of a multinational project (www.mobiguide-project.eu) aimed at developing a ubiquitous patient guidance system (PGS).

Discussion The vMR model with its extension mechanism is demonstrated to be effective for data integration and communication within a distributed PGS implemented for two clinical domains across different healthcare settings in two nations.
Readability of patient discharge instructions with and without the use of electronically available disease-specific templates
Authors: Mueller Stephanie K , Giannelli Kyla , Boxer Robert , Schnipper Jeffrey L
Published: April 2015

Objective Low health literacy is common, leading to patient vulnerability during hospital discharge, when patients rely on written health instructions. We aimed to examine the impact of the use of electronic, patient-friendly, templated discharge instructions on the readability of discharge instructions provided to patients at discharge.

Materials and Methods We performed a retrospective cohort study of 233 patients discharged from a large tertiary care hospital to their homes following the implementation of a web-based “discharge module,” which included the optional use of diagnosis-specific templated discharge instructions. We compared the readability of discharge instructions, as measured by the Flesch Reading Ease Level test (FREL, on a 0–100 scale, with higher scores indicating greater readability) and the Flesch–Kincaid Grade Level test (FKGL, measured in grade levels), between discharges that used templated instructions (with or without modification) versus discharges that used clinician-generated instructions (with or without available templated instructions for the specific discharge diagnosis).

Results Templated discharge instructions were provided to patients in 45% of discharges. Of the 55% of patients that received clinician-generated discharge instructions, the majority (78.1%) had no available templated instruction for the specific discharge diagnosis. Templated discharge instructions had higher FREL scores (71 vs. 57, P < .001) and lower FKGL scores (5.6 vs. 7.6, P < .001), compared to clinician-generated discharge instructions.

Discussion The use of electronically available templated discharge instructions was associated with better readability (a higher FREL score and a lower FKGL score) than the use of clinician-generated discharge instructions. The main reason for clinicians to create discharge instructions was the lack of available templates for the patient’s specific discharge diagnosis.

Conclusions Use of electronically available templated discharge instructions may be a viable option to improve the readability of written material provided to patients at discharge, although the library of available templates requires expansion.
Measles in Canada Between 2002 and 2013
Authors: De Serres Gaston , Desai Shalini , Shane Amanda , Hiebert Joanne , Ouakki Manale , Severini Alberto
Published: April 2015

Background.  In 1994, Canada committed to eliminate measles by the year 2000. This report presents the epidemiology of measles in Canada between 2002 and 2013 and its implications in sustaining measles elimination.

Methods.  Cases included individuals reported to the Canadian Measles and Rubella Surveillance System with confirmed measles.

Results.  In Canada, 1171 cases of measles were reported between 2002 and 2013 (incidence 0.29 cases per 100 000 population). The annual number of cases ranged from 6 to 752. The majority of cases were unvaccinated (63%) or had an unknown vaccination status (19%). The median age of cases was 14.4 years (range, <1 to 63 years) globally and 14 years when excluding the 2011 outbreak in Quebec where 68% of the 678 cases were 10 to 19 years old. With the exclusion of this outbreak, the incidence was highest in infants (1.0 per 100 000), lower but fairly similar between 1 and 19 years of age (0.2 to 0.4 per 100 000), and there was a substantial decline between 20 and 39 years of age (0.1 per 100 000). There was a significant trend towards a greater annual number of importations over the period. Although importations resulted in no transmission sustained for ≥12 months, 5 chains of transmission had >30 cases. The effective reproductive number between 2002 and 2013 was estimated at 0.86 (95% confidence interval, .81–.92).

Conclusions.  Canada has maintained elimination between 2002 and 2013, but additional efforts are needed to reduce the proportion of unimmunized individuals and respond to importation events.
Congenital Parvovirus B19 Infection: Persistent Viremia and Red Blood Cell Aplasia
Authors: Nadimpalli Sruti S. , Miller Russell S. , Kamath Vasudeva M. , Farkouh Christiana R. , Nhan-Chang Chia-Ling , Rathe Jennifer A. , Collins Amélie , Duchon Jennifer M. , Neu Natalie , Simpson Lynn L. , Ratner Adam J.
Published: April 2015

We describe a case of fetal parvovirus B19 infection resulting in preterm birth and leading to hydrops fetalis requiring multiple in utero transfusions. The infant developed chronic postnatal anemia responsive to intravenous immunoglobulin therapy. Serum viral load decreased after immunoglobulin treatment but remained detectable for over 1 year.
Histoplasmosis-Induced Hemophagocytic Syndrome: A Case Series and Review of the Literature
Authors: Townsend Jennifer Leigh , Shanbhag Satish , Hancock John , Bowman Kathryn , Nijhawan Ank E.
Published: April 2015

Background.  Histoplasmosis-associated hemophagocytic lymphohistiocytosis (HLH) is a relatively rare disorder for which data are limited regarding optimal treatment and clinical outcomes in adults. We describe the clinical features, treatment, and outcomes of patients with histoplasmosis-associated HLH at our institution.

Methods.  We performed a retrospective chart review of all inpatients at Parkland Hospital diagnosed with HLH associated with Histoplasma capsulatum from 2003 to 2013.

Results.  Eleven cases of histoplasmosis-associated HLH over this time period were identified. Nine of eleven cases were males (82%). Nine of these patients had human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS), 1 was a renal transplant patient on immunosuppressants, and the other had no documented immunocompromise. The most common HLH criteria were splenomegaly (n = 10), fever (n = 10), and ferritin >500 ng/dL (n = 9). Urine Histoplasma antigen was positive in every patient tested (n = 9 of 9), and most antibodies for Histoplasma were positive if checked (n = 4 of 5). A majority of patients received liposomal amphotericin B (n = 9) with an average treatment duration of 11 days, and 5 patients also received prednisone, intravenous immunoglobulin (IVIG), or both. Overall, 5 patients died within 30 days (45.5%), and 7 patients died within 90 days (63.6%). Of the 5 patients that received immunosuppression, 4 died (80%), whereas in the group not given additional immunosuppression (n = 5), 2 died (40%).

Conclusions.  Histoplasmosis-associated HLH among adults is a lethal disease of highly immunocompromised patients, especially patients with HIV/AIDS. Clinical features such as splenomegaly, elevated ferritin, and cytopenias should prompt evaluation for HLH in this population. Further data are needed to define the role of immunosuppression, IVIG, and highly active antiretroviral therapy in treating this condition.
Intraoperative Tight Glucose Control Using Hyperinsulinemic Normoglycemia Increases Delirium after Cardiac Surgery
Authors: Saager Leif , Duncan Andra E. , Yared Jean-Pierre , Hesler Brian D. , You Jing , Deogaonkar Anupa , Sessler Daniel I. , Kurz Andrea
Published: April 2015

AbstractAbstract

Intraoperative hyperinsulinemic–normoglycemia augments the risk of delirium after cardiac surgery, but not its severity.

Background:

Postoperative delirium is common in patients recovering from cardiac surgery. Tight glucose control has been shown to reduce mortality and morbidity. Therefore, the authors sought to determine the effect of tight intraoperative glucose control using a hyperinsulinemic–normoglycemic clamp approach on postoperative delirium in patients undergoing cardiac surgery.

Methods:

The authors enrolled 198 adult patients having cardiac surgery in this randomized, double-blind, single-center trial. Patients were randomly assigned to either tight intraoperative glucose control with a hyperinsulinemic–normoglycemic clamp (target blood glucose, 80 to 110 mg/dl) or standard therapy (conventional insulin administration with blood glucose target, <150 mg/dl). Delirium was assessed using a comprehensive delirium battery. The authors considered patients to have experienced postoperative delirium when Confusion Assessment Method testing was positive at any assessment. A positive Confusion Assessment Method was defined by the presence of features 1 (acute onset and fluctuating course) and 2 (inattention) and either 3 (disorganized thinking) or 4 (altered consciousness).

Results:

Patients randomized to tight glucose control were more likely to be diagnosed as being delirious than those assigned to routine glucose control (26 of 93 vs. 15 of 105; relative risk, 1.89; 95% CI, 1.06 to 3.37; P = 0.03), after adjusting for preoperative usage of calcium channel blocker and American Society of Anesthesiologist physical status. Delirium severity, among patients with delirium, was comparable with each glucose management strategy.

Conclusion:

Intraoperative hyperinsulinemic–normoglycemia augments the risk of delirium after cardiac surgery, but not its severity.
Growth Arrest Following ACL Reconstruction With Hamstring Autograft in Skeletally Immature Patients: A Review of 4 Cases
Authors: Shifflett Grant D. , Green Daniel W. , Widmann Roger F. , Marx Robert G.
Published: April 2015

Background:

Anterior cruciate ligament (ACL) tears are becoming more common in the skeletally immature population as participation in high-risk sports continues to grow. This presents a challenge for the treating surgeon as ACL reconstruction in this patient set has the added aim of preservation of the growth plate anatomy. The purpose of this investigation is to report on 4 patients who developed growth arrest following ACL reconstruction and offer a review of the available literature.

Methods:

Four skeletally immature patients (2 male and 2 female) were identified who underwent ACL reconstruction at mean age of 14.2 years (range, 13.5 to 14.8 y) and developed growth arrests. Bone ages at the time of reconstruction were 14 and 16 years for the boys and 13 years 6 months and 14 years for the girls. All patients had a transphyseal reconstruction with a hamstring autograft. Standard postoperative care was provided including clinical and radiographic follow-up at regular intervals. Clinically significant postoperative physeal arrest was confirmed on MRI or CT scan. Detailed chart review examined demographics, operative variables, and postoperative subjective and objective clinical measures.

Results:

Two patients developed tibial recurvatum; 2 patients developed genu valgum. Three patients required further surgery. One patient underwent distal femoral–guided growth procedure, 2 underwent proximal tibial epiphysiodesis, and 1 patient was skeletally mature at presentation and did not require deformity correction.

Conclusions:

This report of 4 patients demonstrates that growth arrest following ACL reconstruction in skeletally immature patients is a real concern and highlights the importance of careful preoperative evaluation and discussion with patients and family members. We routinely obtain long-leg AP and lateral hip-to-ankle films on skeletally immature patients before performing an ACL reconstruction and then at 6 and 12 months postoperatively or every 6 months until the growth plates are closed to assess leg lengths and lower extremity alignment.

Level of Evidence:

Level IV—therapeutic study, case series.
Changing Pattern of Femoral Deformity During Growth in Polyostotic Fibrous Dysplasia of the Bone: An Analysis of 46 Cases
Authors: Ippolito Ernesto , Valentini Matteo Benedetti , Lala Roberto , De Maio Fernando , Sorge Roberto , Farsetti Pasquale
Published: April 2015

Background:

In polyostotic fibrous dysplasia (PFD) affecting the femur, 6 types of stable femoral deformities have been identified, ranging from the mild type 1 to the most severe type 6. The purpose of our study was to identify the type of deformity present at diagnosis in children with PFD affecting the femur, and to investigate possible changes in the original type with growth.

Methods:

Twenty-seven children affected by either PFD or McCune-Albright syndrome, with 46 affected femurs, were consecutively observed from 1994 to 2010. Radiographs of the pelvis and femurs were taken at diagnosis, and afterward at regular intervals of 6 to 12 months depending on the clinical evolution of each case. Radiographs of the femurs taken at 3 and 7 years after diagnosis were selected to assess the evolution of the femoral deformity. Deformities were classified according to the femoral shape, neck-shaft angle value, and the presence of shepherd’s crook deformity evaluated on AP radiographs.

Results:

The average age of the patients at diagnosis was 5 years (range, 2 to 11 y). At diagnosis, 30 femurs were type 1; 12, type 2; 1, type 3; 1, type 4; and 2, type 5. Three years later, 39% of the femurs had maintained the original deformity present at diagnosis, whereas only 13% did so 7 years after diagnosis.

Predictors of change to a more severe type were: younger age at diagnosis, McCune-Albright syndrome, rapid spreading of fibrodysplastic tissue from the trochanteric area to the proximal femoral shaft, cortical thinning of the proximal femur, calcar osteolysis, and presence of an intertrochanteric cystic-like lesion eroding the calcar.

Conclusions:

In children with PFD affecting the femur, 61% of the femoral deformity present at diagnosis switched to a more severe type of deformity within 3 years from diagnosis, whereas 87% either shifted to a more severe type of deformity or already had corrective surgery within 7 years after diagnosis.

Level of evidence:

Level IV.
Guided Growth of the Proximal Femur for Hip Displacement in Children With Cerebral Palsy
Authors: Lee Wei-Chun , Kao Hsuan-Kai , Yang Wen-E. , Ho Pei-Chi , Chang Chia-Hsieh
Published: April 2015

Background:

Guided growth by 1 eccentric transphyseal screw has been used to correct lower limb deformities. Pilot animal studies showed encouraging results in producing varus deformity in the proximal femur. The purpose of this study was to report the preliminary results of guided growth surgery to treat spastic hip displacement.

Methods:

This case series study included consecutive patients who received soft-tissue release and guided growth at the proximal femur from January 2004 to May 2012 with minimal 2-year follow-up. Surgical indications were children with spastic cerebral palsy aged 4 to 10 years, a gross motor function classification system level IV or V, and hip displacement on 1 or both sides. Study outcomes were Reimer’s migration percentage (MP) and the head-shaft angle (HSA).

Results:

Nine children with 13 spastic displaced hips received surgery at the age of 6.2 years and were followed up for a mean of 45.6 months. The mean MP improved significantly from 52.2% preoperatively to 45.8% at 3 months, 40.3% at 1 year, and 37.1% at 2 years after operation. HSA was unchanged in the first 3 months, and deceased from 173.3 to 166.4 degrees at 1 year (P<0.01) and to 162.7 degrees at 2 years postoperatively. The screw was usually backed out from the femoral epiphysis in the second postoperative year, and no radiologic bony bar or other surgical complications occurred.

Conclusions:

The immediate postoperative improvement of MP was the result of soft-tissue release. From postoperative 3 months to 2 years, the HSA was reduced by 10.6 degrees and the MP further improved by 8.7%. Less surgical dissection, faster recovery of motion, and less comorbidity than varus osteotomy make guided growth surgery a treatment option for coxa valga in spastic hip displacement in nonambulant cerebral palsy children.

Level of Evidence:

Level IV—therapeutic, case series.
What’s New in the Management of Neuromuscular Scoliosis
Authors: Brooks Jaysson T. , Sponseller Paul D.
Published: April 2015

Background:

Patients with neuromuscular scoliosis (NMS) can pose treatment challenges related to medical comorbidities and altered spinopelvic anatomy. We reviewed the recent literature regarding evaluation and management of NMS patients and explored areas where further research is needed.

Methods:

We searched the PubMed database for all papers related to the treatment of NMS published from January 1, 2011 through July 31, 2014, yielding 70 papers.

Results:

A total of 39 papers contributed compelling new findings. Steroid treatment has been most promising in patients with Duchenne muscular dystrophy, leading to a significantly lower death rate, better pulmonary function, and longer independent ambulation. Growing rods in early-onset NMS were shown to result in significant improvements in major Cobb angles and pelvic obliquity, with low complication rates in patients with spinal muscular atrophy but high infection rates in those with cerebral palsy. Early reports of magnetic growing rods in NMS patients are favorable. Intraoperative neural monitoring is variable in this patient population; however, use of transcranial motor-evoked potentials in NMS patients seems to be safe. Blood loss is the highest in NMS patients when compared with all other diagnostic categories. However, tranexamic acid seems to significantly lower intraoperative blood loss. In a multicenter study, patients diagnosed with NMS had the highest surgical-site infection rate at 13.1%. Best-practice guidelines have been created regarding prevention of infection in NMS patients. Preoperative nutritional optimization and postoperative nutritional supplementation seem to help with lowering the infection rate in these patients.

Conclusions:

There have been major advances in the management of NMS patients, but many challenges remain. Further multicenter studies and randomized clinical trials are needed, particularly in the areas of infection prophylaxis, nutritional optimization, improvement in intraoperative neural monitoring, and prevention of proximal junctional kyphosis.

Level of Evidence:

Level 4—literature review.
Modelling the emergence of polarity patterns for the intercellular transport of auxin in plants
Authors: Grigolon Silvia , Sollich Peter , Martin Olivier C.
Published: April 2015

The hormone auxin is actively transported throughout plants via protein machineries including the dedicated transporter known as PIN. The associated transport is ordered with nearby cells driving auxin flux in similar directions. Here, we provide a model of both the auxin transport and of the dynamics of cellular polarization based on flux sensing. Our main findings are: (i) spontaneous intracellular PIN polarization arises if PIN recycling dynamics are sufficiently nonlinear, (ii) there is no need for an auxin concentration gradient and (iii) ordered multi-cellular patterns of PIN polarization are favoured by molecular noise.
A novel collagen gel-based measurement technique for quantitation of cell contraction force
Authors: Jin Tianrong , Li Li , Siow Richard C. M. , Liu Kuo-Kang
Published: April 2015

Cell contraction force plays an important role in wound healing, inflammation, angiogenesis and metastasis. This study describes a novel method to quantify single cell contraction force
in vitro
using human aortic adventitial fibroblasts embedded in a collagen gel. The technique is based on a depth sensing nano-indentation tester to measure the thickness and elasticity of collagen gels containing stimulated fibroblasts and a microscopy imaging system to estimate the gel area. In parallel, a simple theoretical model has been developed to calculate cell contraction force based on the measured parameters. Histamine (100 µM) was used to stimulate fibroblast contraction while the myosin light chain kinase inhibitor ML-7 (25 µM) was used to inhibit cell contraction. The collagen matrix used in the model provides a physiological environment for fibroblast contraction studies. Measurement of changes in collagen gel elasticity and thickness arising from histamine treatments provides a novel convenient technique to measure cell contraction force within a collagen matrix. This study demonstrates that histamine can elicit a significant increase in contraction force of fibroblasts embedded in collagen, while the Young's modulus of the gel decreases due to the gel degradation.
A review of back-calculation techniques and their potential to inform mitigation strategies with application to non-transmissible acute infectious diseases
Authors: Egan Joseph R. , Hall Ian M.
Published: April 2015

Back-calculation is a process whereby generally unobservable features of an event leading to a disease outbreak can be inferred either in real-time or shortly after the end of the outbreak. These features might include the time when persons were exposed and the source of the outbreak. Such inferences are important as they can help to guide the targeting of mitigation strategies and to evaluate the potential effectiveness of such strategies. This article reviews the process of back-calculation with a particular emphasis on more recent applications concerning deliberate and naturally occurring aerosolized releases. The techniques can be broadly split into two themes: the simpler temporal models and the more sophisticated spatio-temporal models. The former require input data in the form of cases' symptom onset times, whereas the latter require additional spatial information such as the cases' home and work locations. A key aspect in the back-calculation process is the incubation period distribution, which forms the initial topic for consideration. Links between atmospheric dispersion modelling, within-host dynamics and back-calculation are outlined in detail. An example of how back-calculation can inform mitigation strategies completes the review by providing improved estimates of the duration of antibiotic prophylaxis that would be required in the response to an inhalational anthrax outbreak.
Building Genomic Analysis Pipelines in a Hackathon Setting with Bioinformatician Teams: DNA-seq, Epigenomics, Metagenomics and RNA-seq
Authors: Busby Ben , Dillman Allissa , Simpson Claire L. , Fingerman Ian , Yun Sijung , Kristensen David M. , Federer Lisa , Shah Naisha , LaFave Matthew C. , Jimenez-Barron Laura , Pande Manjusha , Luo Wen , Miller Brendan , Mayden Cem , Chandramohan Dhruva , Fletez-Brant Kipper , Bible Paul W. , Nowoshilow Sergej , Chan Alfred , Galvez Eric JC , Chignell Jeremy , Paulson Joseph N. , Kandpal Manoj , Yoon Suhyeon , Asaki Esther , Nellore Abhinav , Stine Adam , Sanders Robert , Becker Jesse , Lesko Matt , Abzug Mordechai , Yaschenko Eugene
Published: April 2015

We assembled teams of genomics professionals to assess whether we could rapidly develop pipelines to answer biological questions commonly asked by biologists and others new to bioinformatics by facilitating analysis of high-throughput sequencing data. In January 2015, teams were assembled on the National Institutes of Health (NIH) campus to address questions in the DNA-seq, epigenomics, metagenomics and RNA-seq subfields of genomics. The only two rules for this hackathon were that either the data used were housed at the National Center for Biotechnology Information (NCBI) or would be submitted there by a participant in the next six months, and that all software going into the pipeline was open-source or open-use. Questions proposed by organizers, as well as suggested tools and approaches, were distributed to participants a few days before the event and were refined during the event. Pipelines were published on GitHub, a web service providing publicly available, free-usage tiers for collaborative software development (https://github.com/features/). The code was published athttps://github.com/DCGenomics/with separate repositories for each team, starting with hackathon_v001.
Measuring the Contribution of Genomic Predictors to Improving Estimator Precision in Randomized trials
Authors: Patil Prasad , Rosenblum Michael , Leek Jeffrey T.
Published: April 2015

The use of genomic data in the clinic has not been as widespread as was envisioned when sequencing and genomic analysis became common techniques. An underlying difficulty is the direct assessment of how much additional information genomic data are providing beyond standard clinical measurements. This is hard to quantify in the clinical setting where laboratory tests based on genomic signatures are fairly new and there are not sufficient data collected to determine how valuable these tests have been in practice. Here we focus on the potential precision gain from using the popular MammaPrint genomic signature in a covariate-adjusted, randomized clinical trial. We describe how adjustment of an estimator for the average treatment effect using baseline measurements can improve precision. This precision gain can be translated directly into sample size reduction and corresponding cost savings. We conduct a simulation study using genomic and clinical data gathered for breast cancer patients and find that adjusting for clinical factors alone provides a gain in precision of 5-6%, adjusting for genomic factors alone provides a similar gain (5%), and combining the two yields a 2-3% additional gain over only adjusting for clinical covariates.
Intensity matching in cuttlefish
Authors: Laan Andres
Published: April 2015

For efficient background matching it is essential that animals closely match a set of salient visual statistics of their visual surroundings. The mean intensity of a background is a key statistic, because it can be estimated across a large range of viewing distances by a simple computation. We investigated how the dynamic neuromuscular camouflage system of the cuttlefishSepia offcinalisresponds to changes in the mean background intensity of uniform backgrounds. We find that cuttlefish adapt their body intensity in response to variations in the mean background intensity, yet show biases in their body intensity beyond what can be predicted from the limited dynamic range of their camouflage system. On sandy backgrounds of various reflectance values their uniform body patterns maintain a constant yellow hue. This color constancy may represent an example of a color prior in a colorblind animal because a yellow body color would be the optimal hue for camouflage on sands typically encountered in their natural environment. Cuttlefish adapt their appearance to the background via a dynamic process composed of a complex mixture of intensity transients spanning timescales from the subsecond to the minute range. In very young animals camouflaging on dark sands the masquerade strategy is preferred over background matching. Masquerade is implemented by combining partial background matching with frequent expression of disruptive components. We furthermore provide an objective definition of disruptive components using hierarchical clustering and automated image analysis thus highlighting the role of chromatophore activity correlations in structuring the motor output ofS.officinalis.
Household-level linkages between off-farm employment and agricultural fixed assets in rural China
Authors: Su Weiliang , Liu Chengfang , Zhang Linxiu , Luo Renfu , YI Hongmei
Published: April 2015

Purpose

– The purpose of this paper is to examine the impact of off-farm employment on agricultural fixed assets among households in rural China.

Design/methodology/approach

– The authors drew on panel data from two rounds of household-level surveys of more than 2,000 households in rural China. The two surveys were conducted in 2008 and 2012 in five provinces. The authors used instrumental-variable Tobit model to test whether the current value of agricultural fixed assets differ between households with different levels off-farm employment.

Findings

– The authors observe that off-farm employment has a negative effect on the current value of agricultural fixed assets at the household level in rural China.

Originality/value

– The authors believe that the results will contribute positively to the assessment of the effect of off-farm employment on the investment in agricultural fixed assets at the household level in the context of China.
Urban economic development, changes in food consumption patterns and land requirements for food production in China
Authors: Jiang Li , Seto Karen C. , Bai Junfei
Published: April 2015

Purpose

– The impact of dietary changes associated with urbanization is likely to increase the demand for land for food production. The purpose of this paper is to examine the impact of urban economic development on changes in food demand and associated land requirements for food production.

Design/methodology/approach

– Based on economic estimates from the Almost Ideal Demand System, feed conversion ratios, and crop yields, the authors forecast and compare future dietary patterns and land requirements for two types of urban diets in China.

Findings

– The results show that the expenditure elasticities of oil and fat, meat, eggs, aquatic products, dairy, and liquor for the diet of capital cities are greater than those for the diet of small- and medium-sized cities. The authors forecast that capital city residents will experience a more rapid rate of increase in per capita demand of meat, eggs, and aquatic products, which will lead to much higher per capita land requirements. Projections indicate that total per capita land demand for food production in capital cities will increase by 9.3 percent, from 1,402 to 1,533 m2 between 2010 and 2030, while total per capita land demand in small- and medium-sized cities will increase only by 5.3 percent, from 1,192 to 1,255 m2.

Originality/value

– The results imply that urban economic development can significantly affect the final outcomes of land requirements for food production. Urban economic development is expected to accelerate the rate of change toward an affluent diet, which can lead to much higher future land requirements.
Making critical sense of discriminatory practices in the Canadian workplace
Authors: Hilde Rosalie K. , Mills Albert
Published: April 2015

Purpose

– This paper aims to report on a preliminary study of how professionally qualified immigrants from Hong Kong to Canada make sense of their experiences, particularly workplace opportunities.

Design/methodology/approach

– The study is framed by a Critical Sensemaking approach, involving in-depth interviews with 12 informants from the Hong Kong Chinese community and discursive analysis (Foucault, 1979) of the local and formative contexts in which they are making sense of workplace opportunities.

Findings

– The findings suggest that a dominant discourse of “integration” strongly influences the way that professionally qualified immigrants come to accept the unchallenged assumptions that the government is providing help for them to “get in”; and that ethnic service organizations are offering positive guidance to the immigrants’ workplace goals and opportunities. Immigrants’ identity and self-worth are measured by whether they “get in” – integrate – into so-called mainstream society. The effect of this hidden discourse has been to marginalize some immigrants in relation to workplace opportunities.

Research limitations/implications

– The interplay of structural (i.e. formative contexts and organizational rules), socio-psychological (i.e. sensemaking properties) and discursive contexts (e.g. discourses of immigration) are difficult to detail over time. The interplay – although important – is difficult to document and trace over a relatively short period of time and may, more appropriately lend itself to more longitudinal research.

Practical implications

– This paper strongly suggests that we need to move beyond structural accounts to capture the voice and agency of immigrants. In particular, as we have tried to show, the sensemaking and sensemaking contexts in which immigrants find themselves provide important insights to the immigrant experience.

Social implications

– This paper suggests widespread policy implications, with a call for greater use of qualitative methods in the study of immigrant experience. It is suggested that policymakers need to move beyond uniform and structural approaches to immigration. How selected immigrants in context make sense of their experiences and how this can help to identify improved policies need to be understood.

Originality/value

– This paper is original in going beyond both structural and psychological accounts of immigration. Through the developing method of Critical Sensemaking, the study combines a focus on structure and social psychology and their interplay. Thus, providing insights not only to the broad discriminatory practices that so-called non-White immigrants face in Canada (and likely other industrial societies) but how these are made sense of. The study is also unique in attempting to fuse sensemaking and discourse analysis to show the interaction between individual sensemaking in the context of dominant discourses.
Showing them the door (nicely): rejection discourses and practices of a global elite
Authors: Goxe Francois , Belhoste Nathalie
Published: April 2015

Purpose

– The purpose of this paper is to contribute to a critical approach of the identification and rejection strategies in discourses and practices of a “global elite” of business leaders and managers.

Design/methodology/approach

– A literature review of mainstream and more critical management and sociology literature on global or transnational elites and classes is presented. The identification and rejection discursive strategies of some (French) multinational corporations’ managers and internationalization agents are then empirically and qualitatively observed and analyzed.

Findings

– The findings are interpreted under the following strategies: constructive strategies, reproductive and legitimizing strategies and exclusion strategies. Some members of the global elite deploy a cosmopolitan and welcoming discourse to not only identify legitimate members of that class but also turn this discourse into one of exclusion, that is, find ways through language, and practice, to exclude those they perceive as illegitimate.

Research limitations/implications

– Management research on global elites needs more critical thinking and reflexivity to avoid acting as a mere vector of global managerial doxa. Studying values, practices and reactions of other less “prestigious” classes confronted with those elites (small- and medium-sized enterprises’ entrepreneurs, individuals from emerging countries, etc.) may contribute to such perspective.

Originality/value

– The paper shows that the literature (in management) often speaks very highly of global elites. It identifies some dynamics of power between members of that/those classes and individuals who intend to join them and thus provides explanations about the elite’s unwritten codes of conduct, pre-requisites for consideration and inclusion and shows how global classes/elites discursively legitimize and exclude others.
Trends in hospitality management research: a personal reflection
Authors: Ryan Chris
Published: April 2015

Purpose

– The purpose of this paper is to provide a personal view of changes and trends in hospitality research since the formation of the International Journal of Contemporary Hospitality Research, and the context of those changes.

Design/methodology/approach

– A micro-auto-ethnographic approach is used based on observation and experiences of the author as an editor of a journal since 1993.

Findings

– As with other forms of research, hospitality research has become commodified by universities, has been much influenced by changes in greater availability of analytical software packages, and been much influenced by new challenges in the industry, notably globalisation and the rise of Asia.

Originality/value

– The paper provides a list of current issues for research within a context of changing demands being made on academic researchers.
The effect of Medicare Part D on prescription drug composition and demand
Authors: Zimmer David
Published: April 2015

Purpose

– The US Medicare Modernization Act of 2003 introduced optional prescription drug coverage, beginning in 2006, widely known as Medicare Part D. This paper uses up-to-date nationally representative survey data to investigate the impact of Part D not only on drug spending and consumption, but also on the composition of drug consumption. The paper aims to discuss these issues.

Design/methodology/approach

– Specifically, the paper investigates whether Part D impacted the number of therapeutic classes for which drugs were prescribed, and also whether Part D lead to increased usage of drugs for specific medical conditions that typically receive drug-intensive therapies.

Findings

– In addition to confirming findings from previous studies, this paper shows that Part D increased the number of therapeutic classes to which seniors receive drugs by approximately four classes. Part D also lead to increased usage of drugs used to treat upper respiratory disease, hypertension, and diabetes.

Originality/value

– While mostly concurring with previous studies on the spending impacts of Part D, this paper is the first to shed light on other impacts of Part D, specifically with respect to its impact on therapeutic classes for which drugs are prescribed.