bluuebunny/crossref_metadata_2025 huggingface dataset:
Obtaining Blood Cultures by Venipuncture versus from Central Lines Impact on Blood Culture Contamination Rates and Potential Effect on Central Line–Associated Bloodstream Infection Reporting
Authors: Boyce John M. , Nadeau Jacqueline , Dumigan Diane , Miller Debra , Dubowsky Cindy , Reilly Lenore , Hannon Carla V.
Published: August 2013

Objective.

Reduce the frequency of contaminated blood cultures that meet National Healthcare Safety Network definitions for a central line-associated bloodstream infection (CLABSI).

Design.

An observational study.

Setting.

A 500-bed university-affiliated hospital.

Methods.

A new blood culture policy discouraged drawing blood samples from central lines. Phlebotomists were reeducated regarding aseptic technique when obtaining blood samples by venipuncture. The intravenous therapy team was taught how to draw blood samples by venipuncture and served as a backup when phlebotomists were unable to obtain blood samples. A 2-nurse protocol and a special supply kit for obtaining blood samples from catheters were developed. Rates of blood culture contamination were monitored by the microbiology laboratory.

Results.

The proportion of blood samples obtained for culture from central lines decreased from 10.9% during January–June 2010 to 0.4% during July–December 2012 (P< .001). The proportion of blood cultures that were contaminated decreased from 84 (1.6%) of 5,274 during January–June 2010 to 21 (0.5%) of 4,245 during January–June 2012 (P< .001). Based on estimated excess hospital costs of $3,000 per contaminated blood culture, the reduction in blood culture contaminants yielded an estimated annualized savings of $378,000 in 2012 when compared to 2010. In mid-2010, 3 (30%) of 10 reported CLABSIs were suspected to represent blood culture contamination compared with none of 6 CLABSIs reported from mid-November 2010 through June 2012 (P= 0.25).

Conclusions.

Multiple interventions resulted in a reduction in blood culture contamination rates and substantial cost savings to the hospital, and they may have reduced the number of reportable CLABSIs.
A tightness property of a symmetric Markov process and the uniform large deviation principle
Authors: Takeda Masayoshi
Published: August 2013

Previously, we considered a large deviation for occupation measures of a symmetric Markov processes under the condition that its resolvent possesses a kind of tightness property. In this paper, we prove that if the Markov process is conservative, then the tightness property implies the uniform hyper-exponential recurrence, which leads us to the uniform large deviation principle.
The number of solutions of a diophantine equation over a recursive ring
Authors: Baxa Christoph
Published: August 2013

Let

R
R

be a recursive ring whose quotient field is not algebraically closed with the property that Hilbert’s Tenth Problem over

R
R

is undecidable, and let

A
A

be a non-empty proper subset of

{
0
,
1
,
2
,
…
}
∪
{

ℵ
0

}

\{0,1,2,\ldots \}\cup \{\aleph _0\}

. We prove that it is not decidable whether the number of solutions of a diophantine equation with coefficients in

R
R

is in

A
A

.
Glycosylation-independent ERAD pathway serves as a backup system under ER stress
Authors: Ushioda Ryo , Hoseki Jun , Nagata Kazuhiro
Published: August 2013

During endoplasmic reticulum (ER)–associated degradation (ERAD), terminally misfolded proteins are retrotranslocated from the ER to the cytosol and degraded by the ubiquitin-proteasome system. Misfolded glycoproteins are recognized by calnexin and transferred to EDEM1, followed by the ER disulfide reductase ERdj5 and the BiP complex. The mechanisms involved in ERAD of nonglycoproteins, however, are poorly understood. Here we show that nonglycoprotein substrates are captured by BiP and then transferred to ERdj5 without going through the calnexin/EDEM1 pathway; after cleavage of disulfide bonds by ERdj5, the nonglycoproteins are transferred to the ERAD scaffold protein SEL1L by the aid of BiP for dislocation into the cytosol. When glucose trimming of the N-glycan groups of the substrates is inhibited, glycoproteins are also targeted to the nonglycoprotein ERAD pathway. These results indicate that two distinct pathways for ERAD of glycoproteins and nonglycoproteins exist in mammalian cells, and these pathways are interchangeable under ER stress conditions.
Distinct roles for antiparallel microtubule pairing and overlap during early spindle assembly
Authors: Nazarova Elena , O'Toole Eileen , Kaitna Susi , Francois Paul , Winey Mark , Vogel Jackie
Published: August 2013

During spindle assembly, microtubules may attach to kinetochores or pair to form antiparallel pairs or interpolar microtubules, which span the two spindle poles and contribute to mitotic pole separation and chromosome segregation. Events in the specification of the interpolar microtubules are poorly understood. Using three-dimensional electron tomography and analysis of spindle dynamical behavior in living cells, we investigated the process of spindle assembly. Unexpectedly, we found that the phosphorylation state of an evolutionarily conserved Cdk1 site (S360) in γ-tubulin is correlated with the number and organization of interpolar microtubules. Mimicking S360 phosphorylation (S360D) results in bipolar spindles with a normal number of microtubules but lacking interpolar microtubules. Inhibiting S360 phosphorylation (S360A) results in spindles with interpolar microtubules and high-angle, antiparallel microtubule pairs. The latter are also detected in wild-type spindles <1 μm in length, suggesting that high-angle microtubule pairing represents an intermediate step in interpolar microtubule formation. Correlation of spindle architecture with dynamical behavior suggests that microtubule pairing is sufficient to separate the spindle poles, whereas interpolar microtubules maintain the velocity of pole displacement during early spindle assembly. Our findings suggest that the number of interpolar microtubules formed during spindle assembly is controlled in part through activities at the spindle poles.
Meta-analysis of the effects of indoor nitrogen dioxide and gas cooking on asthma and wheeze in children
Authors: Lin Weiwei , Brunekreef Bert , Gehring Ulrike
Published: August 2013

Background Since the meta-analysis on the association between indoor nitrogen dioxide (NO2) and childhood respiratory illness in 1992, many new studies have been published. The quantitative effects of indoor NO2 on respiratory illness have not been estimated in a formal meta-analysis since then. We aimed to quantify the association of indoor NO2 and its main source (gas cooking) with childhood asthma and wheeze.

Methods We extracted the association between indoor NO2 (and gas cooking) and childhood asthma and wheeze from population studies published up to 31 March 2013. Data were analysed by inverse-variance-weighted, random-effects meta-analysis. Sensitivity analyses were conducted for different strata. Publication bias and heterogeneity between studies were investigated.

Results A total of 41 studies met the inclusion criteria. The summary odds ratio from random effects meta-analysis for asthma and gas cooking exposure was 1.32 [95% confidential interval (CI) 1.18–1.48], and for a 15-ppb increase in NO2 it was 1.09 (95% CI 0.91–1.31). Indoor NO2 was associated with current wheeze (random effects OR 1.15; 95% CI 1.06–1.25). The estimates did not vary much with age or between regions. There was no evidence of publication bias.

Conclusions This meta-analysis provides quantitative evidence that, in children, gas cooking increases the risk of asthma and indoor NO2 increases the risk of current wheeze.
Colonic Manometry and Colonic Scintigraphy as a Diagnostic Tool for Children With Severe Constipation
Authors: Mugie Suzanne M. , Perez Maria E. , Burgers Rosa , Hingsbergen Elizabeth A. , Punati Jaya , Mousa Hayat , Benninga Marc A. , Di Lorenzo Carlo
Published: August 2013

Objective:

In adults, colonic manometry and colonic scintigraphy are both valuable studies in discriminating normal and abnormal colonic motility. The objective of this study was to compare the diagnostic yield and tolerability of colonic manometry and colonic scintigraphy in children with severe constipation.

Methods:

Twenty‐six children (mean age 11.4 years, 77% boys) who had received colonic manometry and colonic scintigraphy as part of a colonic motility evaluation were included. Manometry was performed as per department protocol. After swallowing a methacrylate‐coated capsule containing indium‐111, images were taken at 4, 24, and 48 hours, and geometric centers were calculated. Results of both tests were categorized in 3 groups: normal, abnormal function in the distal part of the colon, and colonic inertia. Cohen κ was used for the level of agreement. Patients and parents completed a questionnaire regarding their experience.

Results:

Colonic scintigraphy showed normal transit time in 20%, delay in the distal colon in 48%, and colonic inertia in 32% of patients. Colonic manometry was normal in 40%, abnormal in the distal colon in 40%, and colonic inertia was diagnosed in 20%. The κ score was 0.34. All 5 patients with colonic inertia during manometry had a similar result by scintigraphy. Eighty‐eight percent of patients preferred scintigraphy over manometry and 28% of parents preferred colonic manometry over scintigraphy.

Conclusions:

Colonic manometry and colonic scintigraphy have a fair agreement regarding the categorization of constipation. Scintigraphy is well tolerated in pediatric patients and may be a useful tool in the evaluation of children with severe constipation.
Anemia and Iron Deficiency in Children
Authors: Moshe Galit , Amitai Yona , Korchia Gerard , Korchia Levana , Tenenbaum Ariel , Rosenblum Joseph , Schechter Avi
Published: August 2013

Objective:

The aim of this study was to study the relative contribution of dietary sources of iron in children with high prevalence of anemia and iron deficiency (ID).

Methods:

A cross‐sectional study in 263 healthy, 1.5‐ to 6‐year‐old children in the Jewish sector of Jerusalem, Israel. Venous blood samples and a qualitative Food Frequency Questionnaire on iron‐rich foods were obtained. Anemia was defined as hemoglobin <11 g/dL for children younger than 4 years and <11.5 g/dL for children older than 4 years; ID was defined as ferritin <12 μg/L.

Results:

Anemia was found in 11.2%, ID in 22%, and iron‐deficiency anemia in 3.7%. The prevalence of anemia was higher in toddlers ages 1.5 to 3 years compared with children ages 3 to 6 years (17.7% vs 7.3%, P = 0.01). Children with extremely low red meat consumption (seldom) had 4‐fold higher rates of ID than those who consumed ≥2 times per week (odds ratio 3.98; 95% confidence interval 1.21–13.03; P = 0.023), whereas poultry consumption was not associated with ID. Soy consumption was inversely associated with ferritin (marginally significant, r = −0.134, P = 0.057).

Conclusions:

The high prevalence of anemia and ID found in this study, mainly in children 1.5 to 3 years old, is related to low red meat consumption. The characteristically high poultry consumption in the Israeli population was not protective. The shift toward reduced red meat consumption and higher poultry consumption in developed countries may result in increasing the risk of ID.
Association of INSIG2 rs9308762 With ALT Level Independent of BMI
Authors: Guan Li , Shang Xiao‐Rui , Liu Fang‐Hong , Song Jie‐Yun , Ma Jun , Wang Hai‐Jun
Published: August 2013

Objectives:

An increasing number of people are at risk for developing nonalcoholic fatty liver disease (NAFLD). Because obesity is a risk factor for NAFLD, the common variants of obesity‐susceptible genes may be associated with NAFLD. Our aim was to identify whether the obesity‐susceptible gene variants (rs9939609, rs9930506, and rs4783819 in fat mass and obesity‐associated gene (FTO); rs12970134 and rs17782313 in melanocortin‐4 receptor gene (MC4R); and rs7566605, rs13428113, and rs9308762 in insulin‐induced gene 2 [INSIG2]) were associated with NAFLD.

Methods:

The case‐control study recruited 1027 Chinese children ages 7 to 18 years, including 162 children with NAFLD and 865 children without NAFLD. Anthropometric measurements, alanine transaminase (ALT) detection, liver ultrasound examination, and genotyping of 8 gene variants were performed.

Results:

The A‐allele of FTO rs9939609 was associated with increased NAFLD risk (P = 0.029, odds ratio 1.43), but was not significant after being adjusted for body mass index (BMI) (P = 0.268). We also found an association between the 2 variants (rs12970134 in MC4R and rs9308762 in INSIG2) and ALT level. For rs12970134, each additional A‐allele increased ALT level by 1.87 IU/L (P = 0.032). For rs9308762, the homozygotes of the C‐allele had a higher ALT level than the T‐allele carriers (β = 3.19, P = 0.007). After adjustment for BMI, the former association did not exist, whereas the latter reminded significant (P = 0.003).

Conclusions:

The FTO rs9939609 A‐allele increased risk of NAFLD and MC4R rs12970134 was associated with ALT level through an effect on BMI. The association between INSIG2 rs9308762 and ALT level was independent of BMI. The results provided evidence for identifying genetic factors of NAFLD and may be useful for risk assessment and personalized medicine of NAFLD.
A Practical Guide for the Diagnosis of Primary Enteric Nervous System Disorders
Authors: Schäppi M.G. , Staiano A. , Milla P.J. , Smith V.V. , Dias J.A. , Heuschkel R. , Husby S. , Mearin M.L. , Papadopoulou A. , Ruemmele F.M. , Vandenplas Yvan , Koletzko S.
Published: August 2013

Objective:

Primary gastrointestinal neuropathies are a heterogeneous group of enteric nervous system (ENS) disorders that continue to cause difficulties in diagnosis and histological interpretation. Recently, an international working group published guidelines for histological techniques and reporting, along with a classification of gastrointestinal neuromuscular pathology. The aim of this article was to review and summarize the key issues for pediatric gastroenterologists on the diagnostic workup of congenital ENS disorders. In addition, we provide further commentary on the continuing controversies in the field.

Results:

Although the diagnostic criteria for Hirschsprung disease are well established, those for other forms of dysganglionosis remain ill‐defined. Appropriate tissue sampling, handling, and expert interpretation are crucial to maximize diagnostic accuracy and reduce interobserver variability. The absence of validated age‐related normal values for neuronal density, along with the lack of correlation between clinical and histological findings, result in significant diagnostic uncertainties while diagnosing quantitative aberrations such as hypoganglionosis or ultrashort Hirschsprung disease. Intestinal neuronal dysplasia remains a histological description of unclear significance.

Conclusions:

The evaluation of cellular quantitative or qualitative abnormalities of the ENS for clinical diagnosis remains complex. Such analysis should be carried out in laboratories that have the necessary expertise and access to their own validated reference values.
Colonic Lymphoid Nodular Hyperplasia in Childhood
Authors: Gurkan Odul E. , Yilmaz Guldal , Aksu Aysel U. , Demirtas Zeliha , Akyol Gulen , Dalgic Buket
Published: August 2013

Objectives:

The clinical importance and etiology of colonic lymphoid nodular hyperplasia (LNH) are not clear. It has been considered a response to some antigenic stimuli. Although food allergies, infections, inflammatory bowel diseases, and immunodeficiencies may be listed in the etiology of colonic LNH, the etiology has remained unclear in many cases. This study investigated the etiology of colonic LNH and its relation to familial Mediterranean fever (FMF) in children. FMF as an etiologic factor for colonic LNH has not been reported before in the literature.

Methods:

Medical files of patients who underwent colonoscopy between 2007 and 2011 were examined retrospectively. Demographic features, presenting symptoms, colonoscopy indications, colonoscopic findings, and final diagnoses of patients were evaluated. According to etiologies, patients with colonic LNH were divided into 2 groups: group A consisted of patients with FMF and group B consisted of diseases other than FMF.

Results:

A total of 311 patients were included in the study. Forty (12.6%) patients had isolated colonic LNH. In 23 (57.5%) patients, isolated LNH was observed in some colonic segments and total colonic LNH was noted in 17 (42.5%) patients. FMF was the etiologic factor in 6 (15%) patients. Thirty‐four patients (85%) had etiologic factors other than FMF. We did not find any etiologic factor for LNH in 3.53% (11/311) of patients.

Conclusions:

FMF may be an etiologic factor for colonic LNH in children besides food allergies, infections, inflammatory bowel diseases, and immunodeficiencies.
Forelimb muscle function in pig-nosed turtles,Carettochelys insculpta: testing neuromotor conservation between rowing and flapping in swimming turtles
Authors: Rivera Angela R. V. , Blob Richard W.
Published: August 2013

Changes in muscle activation patterns can lead to new locomotor modes; however, neuromotor conservation—the evolution of new forms of locomotion through changes in structure without concurrent changes to underlying motor patterns—has been documented across diverse styles of locomotion. Animals that swim using appendages do so via rowing (anteroposterior oscilations) or flapping (dorsoventral oscilations). Yet few studies have compared motor patterns between these swimming modes. In swimming turtles, propulsion is generated exclusively by limbs. Kinematically, turtles swim using multiple styles of rowing (freshwater species), flapping (sea turtles) and a unique hybrid style with superficial similarity to flapping by sea turtles and characterized by increased dorsoventral motions of synchronously oscillated forelimbs that have been modified into flippers (Carettochelys insculpta). We compared forelimb motor patterns in four species of turtle (two rowers,Apalone feroxandTrachemys scripta; one flapper,Caretta caretta; andCarettochelys) and found that, despite kinematic differences, motor patterns were generally similar among species with a few notable exceptions: specifically, presence of variable bursts for pectoralis and triceps inTrachemys(though timing of the non-variable pectoralis burst was similar), and the timing of deltoideus activity inCarettochelysandCarettacompared with other taxa. The similarities in motor patterns we find for several muscles provide partial support for neuromotor conservation among turtles using diverse locomotor styles, but the differences implicate deltoideus as a prime contributor to flapping limb motions.
Towards a richer evolutionary game theory
Authors: McNamara John M.
Published: August 2013

Most examples of the application of evolutionary game theory to problems in biology involve highly simplified models. I contend that it is time to move on and include much more richness in models. In particular, more thought needs to be given to the importance of (i) between-individual variation; (ii) the interaction between individuals, and hence the process by which decisions are reached; (iii) the ecological and life-history context of the situation; (iv) the traits that are under selection, and (v) the underlying psychological mechanisms that lead to behaviour. I give examples where including variation between individuals fundamentally changes predicted outcomes of a game. Variation also selects for real-time responses, again resulting in changed outcomes. Variation can select for other traits, such as choosiness and social sensitivity. More generally, many problems involve coevolution of more than one trait. I identify situations where a reductionist approach, in which a game is isolated from is ecological setting, can be misleading. I also highlight the need to consider flexibility of behaviour, mental states and other issues concerned with the evolution of mechanism.
Magnetoreception: activated cryptochrome 1a concurs with magnetic orientation in birds
Authors: Nießner Christine , Denzau Susanne , Stapput Katrin , Ahmad Margaret , Peichl Leo , Wiltschko Wolfgang , Wiltschko Roswitha
Published: August 2013

The radical pair model proposes that the avian magnetic compass is based on radical pair processes in the eye, with cryptochrome, a flavoprotein, suggested as receptor molecule. Cryptochrome 1a (Cry1a) is localized at the discs of the outer segments of the UV/violet cones of European robins and chickens. Here, we show the activation characteristics of a bird cryptochrome
in vivo
under natural conditions. We exposed chickens for 30 min to different light regimes and analysed the amount of Cry1a labelled with an antiserum against an epitope at the C-terminus of this protein. The staining after exposure to sunlight and to darkness indicated that the antiserum labels only an illuminated, activated form of Cry1a. Exposure to narrow-bandwidth lights of various wavelengths revealed activated Cry1a at UV, blue and turquoise light. With green and yellow, the amount of activated Cry1a was reduced, and with red, as in the dark, no activated Cry1a was labelled. Activated Cry1a is thus found at all those wavelengths at which birds can orient using their magnetic inclination compass, supporting the role of Cry1a as receptor molecule. The observation that activated Cry1a and well-oriented behaviour occur at 565 nm green light, a wavelength not absorbed by the fully oxidized form of cryptochrome, suggests that a state other than the previously suggested Trp
•
/FAD
•
radical pair formed during photoreduction is crucial for detecting magnetic directions.
Colliding peakons and the formation of shocks in the Degasperis–Procesi equation
Authors: Szmigielski Jacek , Zhou Lingjun
Published: August 2013

The Degasperis–Procesi equation (DP) is one of several equations known to model important nonlinear effects such as wave breaking and shock creation. It is, however, a special property of the DP equation that these two effects can be studied in an explicit manner with the help of the multi-peakon ansatz. In essence, this ansatz allows one to model wave breaking as a collision of hypothetical particles (peakons and antipeakons), called henceforth collectively multi-peakons. It is shown that the system of ordinary differential equations describing DP multi-peakons has the Painlevé property which implies a universal wave breaking behaviour, that multipeakons can collide only in pairs, and that there are no multiple collisions other than, possibly simultaneous, collisions of peakon–antipeakon pairs at different locations. Moreover, it is demonstrated that each peakon–antipeakon collision results in creation of a shock thus making possible a multi-shock phenomenon.
Giant field-induced strains in magnetoactive elastomer composites
Authors: Galipeau E. , Ponte Castañeda P.
Published: August 2013

Magnetoactive elastomers (MAEs) are composite materials consisting of nearly rigid, magnetically susceptible particles embedded in a soft, magnetically insensitive elastomer matrix. These multi-functional materials exhibit field-dependent strains and changes in stiffness. However, the strains that have been achieved experimentally to date are still relatively small (of the order of 1%). The reason for these small strains can be traced back to the dipolar nature of the forces between particles. Large particle concentrations are required to generate strong forces, but large concentrations also lead to large overall stiffness for the composite material, which, in turn, tends to reduce the overall strain. In this paper, we propose a new class of MAEs with doubly layered, herringbone-type microstructures capable of generating much larger field-induced strains of up to 100%. This is accomplished by combining the strong action of magnetic torques on suitably oriented magnetic layers, which interact directly with the applied magnetic field, together with the excitation of soft modes of simple shear deformation in the elastomer layers. Theoretical predictions, based on an exact analytical solution for the macroscopic magnetoelastic response of the materials, allow for the optimization of the microstructure for enhanced magnetostriction.
Anthropogenic environments exert variable selection on cranial capacity in mammals
Authors: Snell-Rood Emilie C. , Wick Naomi
Published: August 2013

It is thought that behaviourally flexible species will be able to cope with novel and rapidly changing environments associated with human activity. However, it is unclear whether such environments are selecting for increases in behavioural plasticity, and whether some species show more pronounced evolutionary changes in plasticity. To test whether anthropogenic environments are selecting for increased behavioural plasticity within species, we measured variation in relative cranial capacity over time and space in 10 species of mammals. We predicted that urban populations would show greater cranial capacity than rural populations and that cranial capacity would increase over time in urban populations. Based on relevant theory, we also predicted that species capable of rapid population growth would show more pronounced evolutionary responses. We found that urban populations of two small mammal species had significantly greater cranial capacity than rural populations. In addition, species with higher fecundity showed more pronounced differentiation between urban and rural populations. Contrary to expectations, we found no increases in cranial capacity over time in urban populations—indeed, two species tended to have a decrease in cranial capacity over time in urban populations. Furthermore, rural populations of all insectivorous species measured showed significant increases in relative cranial capacity over time. Our results provide partial support for the hypothesis that urban environments select for increased behavioural plasticity, although this selection may be most pronounced early during the urban colonization process. Furthermore, these data also suggest that behavioural plasticity may be simultaneously favoured in rural environments, which are also changing because of human activity.
Parent–offspring similarity in the timing of developmental events: an origin of heterochrony?
Authors: Tills Oliver , Rundle Simon D. , Spicer John I.
Published: August 2013

Understanding the link between ontogeny (development) and phylogeny (evolution) remains a key aim of biology. Heterochrony, the altered timing of developmental events between ancestors and descendants, could be such a link although the processes responsible for producing heterochrony, widely viewed as an interspecific phenomenon, are still unclear. However, intraspecific variation in developmental event timing, if heritable, could provide the raw material from which heterochronies originate. To date, however, heritable developmental event timing has not been demonstrated, although recent work did suggest a genetic basis for intraspecific differences in event timing in the embryonic development of the pond snail,Radix balthica. Consequently, here we used high-resolution (temporal and spatial) imaging of the entire embryonic development ofR. balthicato perform a parent–offspring comparison of the timing of twelve, physiological and morphological developmental events. Between-parent differences in the timing of all events were good predictors of such timing differences between their offspring, and heritability was demonstrated for two of these events (foot attachment and crawling). Such heritable intraspecific variation in developmental event timing could be the raw material for speciation events, providing a fundamental link between ontogeny and phylogeny, via heterochrony.
Persistent organic pollution in a high-Arctic top predator: sex-dependent thresholds in adult survival
Authors: Erikstad Kjell Einar , Sandvik Hanno , Reiertsen Tone Kristin , Bustnes Jan Ove , Strøm Hallvard
Published: August 2013

In long-lived species, any negative effect of pollution on adult survival may pose serious hazards to breeding populations. In this study, we measured concentrations of various organochlorines (OCs) (polychlorinated biphenyl and OC pesticides) in the blood of a large number of adult glaucous gulls (
Larus hyperboreus
) breeding on Bjørnøya (Bear Island) in the Norwegian Arctic, and modelled their local survival using capture–recapture analysis. Survival was negatively associated with concentrations of OCs in the blood. The effect of OCs was nonlinear and evident only among birds with the highest concentrations (the uppermost deciles of contamination). The threshold for depressed survival differed between the sexes, with females being more sensitive to contamination. For birds with lower OC concentration, survival was very high, i.e. at the upper range of survival rates reported from glaucous and other large gull species in other, presumably less contaminated populations. We propose two non-exclusive explanations. First, at some threshold of OC concentration, parents (especially males) may abandon reproduction to maximize their own survival. Second, high contamination of OC may eliminate the most sensitive individuals from the population (especially among females), inducing a strong selection towards high-quality and less sensitive phenotypes.
Invasive aquarium fish transform ecosystem nutrient dynamics
Authors: Capps Krista A. , Flecker Alexander S.
Published: August 2013

Trade of ornamental aquatic species is a multi-billion dollar industry responsible for the introduction of myriad fishes into novel ecosystems. Although aquarium invaders have the potential to alter ecosystem function, regulation of the trade is minimal and little is known about the ecosystem-level consequences of invasion for all but a small number of aquarium species. Here, we demonstrate how ecological stoichiometry can be used as a framework to identify aquarium invaders with the potential to modify ecosystem processes. We show that explosive growth of an introduced population of stoichiometrically unique, phosphorus (P)-rich catfish in a river in southern Mexico significantly transformed stream nutrient dynamics by altering nutrient storage and remineralization rates. Notably, changes varied between elements; the P-rich fish acted as net sinks of P and net remineralizers of nitrogen. Results from this study suggest species-specific stoichiometry may be insightful for understanding how invasive species modify nutrient dynamics when their population densities and elemental composition differ substantially from native organisms. Risk analysis for potential aquarium imports should consider species traits such as body stoichiometry, which may increase the likelihood that an invasion will alter the structure and function of ecosystems.
Backtracking behaviour in lost ants: an additional strategy in their navigational toolkit
Authors: Wystrach Antoine , Schwarz Sebastian , Baniel Alice , Cheng Ken
Published: August 2013

Ants use multiple sources of information to navigate, but do not integrate all this information into a unified representation of the world. Rather, the available information appears to serve three distinct main navigational systems: path integration, systematic search and the use of learnt information—mainly via vision. Here, we report on an additional behaviour that suggests a supplemental system in the ant's navigational toolkit: ‘backtracking’. Homing ants, having almost reached their nest but, suddenly displaced to unfamiliar areas, did not show the characteristic undirected headings of systematic searches. Instead, these ants backtracked in the compass direction opposite to the path that they had just travelled. The ecological function of this behaviour is clear as we show it increases the chances of returning to familiar terrain. Importantly, the mechanistic implications of this behaviour stress an extra level of cognitive complexity in ant navigation. Our results imply: (i) the presence of a type of ‘memory of the current trip’ allowing lost ants to take into account the familiar view recently experienced, and (ii) direct sharing of information across different navigational systems. We propose a revised architecture of the ant's navigational toolkit illustrating how the different systems may interact to produce adaptive behaviours.
Longitudinal analysis of intra-host simian immunodeficiency virus recombination in varied tissues of the rhesus macaque model for neuroAIDS
Authors: Lamers Susanna L. , Nolan David J. , Strickland Samantha L. , Prosperi Mattia , Fogel Gary B. , Goodenow Maureen M. , Salemi Marco
Published: August 2013

Human immunodeficiency virus intra-host recombination has never been studiedin vivoboth during early infection and throughout disease progression. The CD8-depleted rhesus macaque model of neuroAIDS was used to investigate the impact of recombination from early infection up to the onset of neuropathology in animals inoculated with a simian immunodeficiency virus (SIV) swarm. Several lymphoid and non-lymphoid tissues were collected longitudinally at 21 days post-infection (p.i.), 61 days p.i. and necropsy (75–118 days p.i.) from four macaques that developed SIV-encephalitis or meningitis, as well as from two animals euthanized at 21 days p.i. The number of recombinant sequences and breakpoints in different tissues and over time from each primate were compared. Breakpoint locations were mapped onto predicted RNA and protein secondary structures. Recombinants were found at each time point and in each primate as early as 21 days p.i. No association was found between recombination rates and specific tissue of origin. Several identical breakpoints were identified in sequences derived from different tissues in the same primate and among different primates. Breakpoints predominantly mapped to unpaired nucleotides or pseudoknots in RNA secondary structures, and proximal to glycosylation sites and cysteine residues in protein sequences, suggesting selective advantage in the emergence of specific recombinant sequences. Results indicate that recombinant sequences can become fixed very early after infection with a heterogeneous viral swarm. Features of RNA and protein secondary structure appear to play a role in driving the production of recombinants and their selection in the rapid disease model of neuroAIDS.
Conformational Changes Represent the Rate-Limiting Step in the Transport Cycle of Maize SUCROSE TRANSPORTER1
Authors: Derrer Carmen , Wittek Anke , Bamberg Ernst , Carpaneto Armando , Dreyer Ingo , Geiger Dietmar
Published: August 2013

Proton-driven Suc transporters allow phloem cells of higher plants to accumulate Suc to more than 1 M, which is up to ∼1000-fold higher than in the surrounding extracellular space. The carrier protein can accomplish this task only because proton and Suc transport are tightly coupled. This study provides insights into this coupling by resolving the first step in the transport cycle of the Suc transporter SUT1 from maize (Zea mays). Voltage clamp fluorometry measurements combining electrophysiological techniques with fluorescence-based methods enable the visualization of conformational changes of SUT1 expressed in Xenopus laevis oocytes. Using the Suc derivate sucralose, binding of which hinders conformational changes of SUT1, the association of protons to the carrier could be dissected from transport-associated movements of the protein. These combined approaches enabled us to resolve the binding of protons to the carrier and its interrelationship with the alternating movement of the protein. The data indicate that the rate-limiting step of the reaction cycle is determined by the accessibility of the proton binding site. This, in turn, is determined by the conformational change of the SUT1 protein, alternately exposing the binding pockets to the inward and to the outward face of the membrane.
The Arabidopsis METACASPASE9 Degradome
Authors: Tsiatsiani Liana , Timmerman Evy , De Bock Pieter-Jan , Vercammen Dominique , Stael Simon , van de Cotte Brigitte , Staes An , Goethals Marc , Beunens Tine , Van Damme Petra , Gevaert Kris , Van Breusegem Frank
Published: August 2013

Metacaspases are distant relatives of the metazoan caspases, found in plants, fungi, and protists. However, in contrast with caspases, information about the physiological substrates of metacaspases is still scarce. By means of N-terminal combined fractional diagonal chromatography, the physiological substrates of METACASPASE9 (MC9; AT5G04200) were identified in young seedlings of Arabidopsis thaliana on the proteome-wide level, providing additional insight into MC9 cleavage specificity and revealing a previously unknown preference for acidic residues at the substrate prime site position P1′. The functionalities of the identified MC9 substrates hinted at metacaspase functions other than those related to cell death. These results allowed us to resolve the substrate specificity of MC9 in more detail and indicated that the activity of phosphoenolpyruvate carboxykinase 1 (AT4G37870), a key enzyme in gluconeogenesis, is enhanced upon MC9-dependent proteolysis.
SWOT analysis in the planning of information services and systems in university libraries
Authors: Mapulanga Patrick
Published: August 2013

Purpose

The purpose of this paper is to highlight the impact of strategic plans in the planning of information services and systems in the University of Malawi libraries.

Design/methodology/approach

A case study approach was used as the research design. Both qualitative and quantitative data were collected. Quantitative data were collected from the budget estimates from 2004/2005 to 2009/2010 the financial years. Quantitative data were collected from the UNIMA Strategic Plans (2004/2005‐2009/2010) and (2012/2013‐2016/2017). Other views were collected from a forum group discussion of librarians in UNIMA on what they knew about the two strategic plans. Both qualitative and qualitative data are presented in the form of tables. Quantitative data were analysed by calculating percentage increase/decreases in the figures from the previous year. Qualitative data were analysed thematically

Findings

The strategic plans have guided the planning, budgeting and financing of UNIMA, including the planning of library services and systems. However, despite the formulation of the strategic plans, political, economic, social, internal and external forces have negatively impacted the implementation of the plans. The strategic plans have also failed to represent the wishes of the libraries as an appropriate environmental scan for the UNIMA libraries was not taken into account.

Originality/value

Although planning has been a popular topic in business circles, little is known about the planning that occurs in libraries in developing countries. This study seeks to bridge the information gap on the planning for information resources in the University of Malawi libraries.
Does equity mediate the effects of job demands and job resources on work outcomes?
Authors: Hu Qiao , Schaufeli Wilmar B. , Taris Toon W.
Published: August 2013

Purpose

This study aims to investigate the relation between job demands and job resources on the one hand and employee well‐being (burnout and work engagement) on the other. It was assumed that this relation is mediated by an equity‐based cognitive evaluation process.

Design/methodology/approach

This mediation hypothesis was tested using the Job‐Demands Resources model in two Chinese samples of blue collar workers (n=625) and nurses (n=1,381).

Findings

As expected, structural equation analysis revealed that equity mediated the relation of job demands and job resources with burnout and work engagement among nurses. However, mediation was only partly confirmed among blue collar workers. In addition, and as expected, among nurses equity was non‐linearly related with burnout.

Research limitations/implications

The cross‐sectional design of the present study precludes causal conclusions.

Originality/value

The study extended the JD‐R model with an equity‐based cognitive evaluation process.
Innovation in development organizations: an Indian perspective
Authors: Patnaik Srilata , Shambu Prasad C.
Published: August 2013

Purpose

This article seeks to explore the determinants for innovation in development organizations.

Design/methodology/approach

The methodology included interviews with key personnel of an Indian development organization and data collected from secondary sources like official documents and annual reports.

Findings

Innovation in development organizations are influenced by factors like acceptance by community, flexibility of donor agencies, support of technical institutions, flexibility in policies and leadership in the organization.

Practical implications

The findings could help to create an ecosystem for development organizations to become innovative for better performance.

Originality/value

The article highlights various factors that facilitate innovation in development organizations.
Electronic theses and dissertations in Nigeria university libraries
Authors: Ezema Ifeanyi J. , Ugwu C.I.
Published: August 2013

Purpose

The purpose of this paper is to investigate the current status of electronic theses and dissertations (ETD) projects in Nigerian university libraries.

Design/methodology/approach

A survey research methodology was applied. A total of 125 questionnaires were distributed to librarians in eight government‐funded universities in South Eastern Nigeria.

Findings

Only three out of the eight universities surveyed have started ETD projects in their libraries. Other universities have the intention of adopting ETD but very little has been done towards this. The study also revealed that university libraries in Nigeria stand to benefit immensely from ETD projects. Some of these benefits as revealed from the findings include enhancing scholarly communication in Nigeria, promoting the global visibility of Nigerian universities, and enhancing research dissemination. The results of the study also revealed some challenges of ETD in Nigeria. Strategies to mitigate these challenges were also identified from the findings.

Practical implications

The paper establishes that the adoption of ETD in Nigerian university libraries is very low. Nigerian universities must therefore adopt a pragmatic approach to develop an ETD program that will facilitate the dissemination of research documented in theses and dissertations.

Originality/value

The originality of the work lies in the empirical evidence obtained from the eight university libraries surveyed.
A CERIF‐based schema for recording research impact
Authors: Gartner Richard , Cox Mark , Jeffery Keith
Published: August 2013

Purpose

The need for a more structured methodology than currently exists for describing the impact of academic research is widely acknowledged. The most widely used research information standard, CERIF, does not currently allow the encoding of research impact in a structured way: this project devised and tested an extension to CERIF to address this omission. The paper seeks to discuss these points.

Design/methodology/approach

The core methodology of the project is a series of extensions to the CERIF model to encode “impact statements”, indicators of impact and measures as evidence for them. These can be linked to persons, organisational units or research outputs. This model is supported by a small semantic taxonomy of indicators and measures. The model was tested by evaluating it against current information environments, and by assessing its compatibility with CERIF and non‐CERIF compliant current research information systems.

Findings

Despite some concerns expressed about the validity of reducing qualitative evidence of impact to atomistic measures, and about a general paucity of such data in existing systems, the model tested well against working environments. It offers the potential for reducing workloads and more continuous assessment of research impact within its stakeholder communities.

Originality/value

No substantive methodology for encoding impact statements existed in CERIF prior to this project. In addition, the atomistic, quantifiable approach to describing impact is relatively unexplored in the higher education community, but offers substantial advantages. The work is of relevance to research managers, developers, system designers and metadata specialists.
Overcoming challenges in the implementation of performance measurement
Authors: Jääskeläinen Aki , Sillanpää Virpi
Published: August 2013

Purpose

The paper aims to evaluate factors affecting the success of the measurement system implementation in the context of two case services with a specific measurement object – productivity.

Design/methodology/approach

Interviews with the users of new measurement systems are used to obtain information on the role of known technical and organizational success factors supporting measurement system implementation.

Findings

Two key factors were found to affect the success of the measurement system development project. First, the commitment of the operative level was achieved. Second, the chosen measurement tool was suitable for the identified managerial requirements of the organization.

Research limitations/implications

In order to improve external validity, it would be useful to assess the implementation of measurement systems with a similar approach in different organizations. Could the positive results described in this study be replicated?

Practical implications

The practical implications of this study are twofold. First, the study describes a potential and fresh approach towards measurement of performance and productivity in public organizations. Second, the experiences described can assist public managers to avoid pitfalls in the implementation of measurement systems.

Originality/value

Various challenges in developing measurement systems in the public sector context are well studied. It is important to better understand how to overcome the problems. In comparison to many existing studies, this research provides more specific and detailed knowledge related to a successful development project.
Correlation transmission between crude oil and Indian markets
Authors: Kumar Dilip , Maheswaran S.
Published: August 2013

Purpose

In this paper, the authors aim to investigate the return, volatility and correlation spillover effects between the crude oil market and the various Indian industrial sectors (automobile, financial, service, energy, metal and mining, and commodities sectors) in order to investigate optimal portfolio construction and to estimate risk minimizing hedge ratios.

Design/methodology/approach

The authors compare bivariate generalized autoregressive conditional heteroskedasticity models (diagonal, constant conditional correlation and dynamic conditional correlation) with the vector autoregressive model as a conditional mean equation and the vector autoregressive moving average generalized autoregressive conditional heteroskedasticity model as a conditional variance equation with the error terms following the Student's t distribution so as to identify the model that would be appropriate for optimal portfolio construction and to estimate risk minimizing hedge ratios.

Findings

The authors’ results indicate that the dynamic conditional correlation bivariate generalized autoregressive conditional heteroskedasticity model is better able to capture time‐dynamics in comparison to other models, based on which the authors find evidence of return and volatility spillover effects from the crude oil market to the Indian industrial sectors. In addition, the authors find that the conditional correlations between the crude oil market and the Indian industrial sectors change dynamically over time and that they reach their highest values during the period of the global financial crisis (2008‐2009). The authors also estimate risk minimizing hedge ratios and oil‐stock optimal portfolio holdings.

Originality/value

This paper has empirical originality in investigating the return, volatility and correlation spillover effects from the crude oil market to the various Indian industrial sectors using BVGARCH models with the error terms assumed to follow the Student's t distribution.