bluuebunny/crossref_metadata_2025 huggingface dataset:
Gut hormone activity of children born to women with and without gestational diabetes
Authors: Chandler‐Laney P. C. , Bush N. C. , Rouse D. J. , Mancuso M. S. , Gower B. A.
Published: January 2013

What is already known about this subject

Children born to women with gestational diabetes have greater risk for obesity.

Obesity in adults and children is associated with blunted postprandial gut hormone responses.

What this study adds

Children of women with gestational diabetes have a blunted postprandial response of GLP‐1.

Children of women with gestational diabetes have high fasting PYY concentrations.

Background

Intrauterine exposure to gestational diabetes mellitus (GDM) increases risk for obesity. Obesity is associated with a blunted postprandial gut hormone response, which may impair satiety and thereby contribute to weight gain. The postprandial response of gut hormones among children of women with GDM has not previously been investigated.

Objective

To examine whether children of women with GDM have suppressed peptide‐tyrosine‐tyrosine (PYY) and glucagon‐like‐peptide‐1 (GLP‐1), and higher concentrations of ghrelin, following a meal challenge. A secondary objective was to investigate associations of these hormones with children's free‐living energy intake.

Methods

Children (n = 42) aged 5–10 years were stratified into two groups: offspring of GDM mothers (OGD) and of non‐diabetic mothers (CTRL). Body composition was measured by dual‐energy X‐ray absorptiometry, and circulating PYY, GLP‐1 and total ghrelin were measured during a liquid meal challenge. Energy intake was assessed by three 24‐h diet recalls.

Results

Between‐groups analyses of fasting and incremental area under the curve (AUC) found no differences in ghrelin. Incremental AUC for GLP‐1 was greater among the CTRL vs. OGD (P < 0.05), and fasting PYY, but not incremental AUC, was higher among OGD vs. CTRL (P < 0.01). Associations of fasting and incremental AUC for each gut hormone with children's usual energy intake did not differ significantly by group.

Conclusions

Further research is needed to more fully examine the potential role of postprandial GLP‐1 suppression and high‐fasting PYY concentrations on the feeding behaviour and risk for obesity among children exposed to GDM in utero.
Food insecurity, food assistance and weight status in US youth: new evidence from NHANES 2007–08
Authors: Kohn M. J. , Bell J. F. , Grow H. M. G. , Chan G.
Published: January 2013

What is already known about this subject

Most prior work suggests no consistent association between food assistance programme participation and increased risk for youth overweight.

Previous studies have not accounted for youth food insecurity status, which may modify this relationship.

What this study adds

Associations between food assistance programme participation and youth overweight are modified by food insecurity.

In a national sample, food‐secure youth, but not food‐insecure youth, participating in food assistance programmes had increased body size both by body mass index and waist circumference measures.

Objective

To investigate food assistance participation as a risk factor for overweight and obesity in youth, and food insecurity as an effect modifier.

Methods

The sample included youth ages 4–17, in families ≤200% of the federal poverty line in the 2007–2008 National Health and Nutrition Examination Survey (n = 1321). Food insecurity was measured with the US Department of Agriculture survey module. Food assistance participation was assessed for Supplemental Nutrition Assistance Program, Special Supplemental Nutrition Program for Women, Infants and Children and school meals. Body size was classified by age‐ and sex‐specific body mass index (BMI) percentile, BMI z‐score and waist circumference percentile. Regression models with direct covariate adjustment and programme‐specific propensity scores, stratified by food insecurity, estimated associations between food assistance participation and body size.

Results

Food assistance participation was not associated with increased body size among food‐insecure youth in models with direct covariate adjustment or propensity scores. Compared with low‐income, food‐secure youth not participating in food assistance, BMI z‐scores were higher among participants in models with direct covariate adjustment (0.27–0.38 SD and 0.41–0.47 SD, for boys and girls, respectively). Using propensity scores, results were similar for boys, but less so for girls.

Conclusions

Food assistance programme participation is associated with increased body size in food‐secure youth, but not food‐insecure youth. Using both direct covariate adjustment and a propensity score approach, self‐selection bias may explain some, but not all, of the associations. Providing healthy food assistance that improves diet quality without contributing to excessive intake remains an important public health goal.
Morphology Tunable Self‐Assembled Sr2P2O7:Ce3+, Mn2+ Phosphor and Luminescence Properties
Authors: Xu Meng Jiao , Wang Lu Xiang , Jia Dian Zeng , Liu Lang , Zhang Li , Guo Zai Ping , Sheng Rui
Published: January 2013

Uniform orange‐to‐red spherical phosphors of Sr2P2O7:Ce3+, Mn2+ have been synthesized by the co‐precipitation method and characterized by X‐ray powder diffraction, scanning electron microscopy, and photoluminescence spectroscopy. The results indicate that the morphology, size, and photoluminescence properties of Sr2P2O7:Ce3+, Mn2+ phosphors can be effectively controlled by the reaction and the sintering temperatures. Energy transfer from Ce3+ to Mn2+ in Sr2P2O7 phosphor was observed from photoluminescence spectra of Sr2P2O7:Ce3+, Sr2P2O7:Mn2+, and Sr2P2O7:Ce3+, Mn2+. Moreover, based on a self‐assembly process, a possible formation mechanism for the spherical phosphors is proposed. The uniform phosphor spheres obtained in this work exhibit great potential for high‐resolution display devices such as light emitting diodes.
Monoclonal antibodies selective for α‐synuclein oligomers/protofibrils recognize brain pathology in Lewy body disorders and α‐synuclein transgenic mice with the disease‐causing A30P mutation
Authors: Fagerqvist Therese , Lindström Veronica , Nordström Eva , Lord Anna , Tucker Stina M. E. , Su Xingjian , Sahlin Charlotte , Kasrayan Alex , Andersson Jessica , Welander Hedvig , Näsström Thomas , Holmquist Mats , Schell Heinrich , Kahle Philipp J. , Kalimo Hannu , Möller Christer , Gellerfors Pär , Lannfelt Lars , Bergström Joakim , Ingelsson Martin
Published: January 2013

Inclusions of intraneuronal alpha‐synuclein (α‐synuclein) can be detected in brains of patients with Parkinson's disease and dementia with Lewy bodies. The aggregation of α‐synuclein is a central feature of the disease pathogenesis. Among the different α‐synuclein species, large oligomers/protofibrils have particular neurotoxic properties and should therefore be suitable as both therapeutic and diagnostic targets. Two monoclonal antibodies, mAb38F and mAb38E2, with high affinity and strong selectivity for large α‐synuclein oligomers were generated. These antibodies, which do not bind amyloid‐beta or tau, recognize Lewy body pathology in brains from patients with Parkinson's disease and dementia with Lewy bodies and detect pathology earlier in α‐synuclein transgenic mice than linear epitope antibodies. An oligomer‐selective sandwich ELISA, based on mAb38F, was set up to analyze brain extracts of the transgenic mice. The overall levels of α‐synuclein oligomers/protofibrils were found to increase with age in these mice, although the levels displayed a large interindividual variation. Upon subcellular fractionation, higher levels of α‐synuclein oligomers/protofibrils could be detected in the endoplasmic reticulum around the age when behavioral disturbances develop. In summary, our novel oligomer‐selective α‐synuclein antibodies recognize relevant pathology and should be important tools to further explore the pathogenic mechanisms in Lewy body disorders. Moreover, they could be potential candidates both for immunotherapy and as reagents in an assay to assess a potential disease biomarker.
Calmodulin Kinase IV–dependent CREB activation is required for neuroprotection via NMDA receptor‐PSD95 disruption
Authors: Bell Karen F. S. , Bent Russell J. , Meese‐Tamuri Saira , Ali Alicia , Forder Joan P. , Aarts Michelle M.
Published: January 2013

NMDA‐type glutamate receptors mediate both trophic and excitotoxic signalling in CNS neurons. We have previously shown that blocking NMDAR‐ post‐synaptic density‐95 (PSD95) interactions provides significant protection from excitotoxicity and in vivo ischaemia; however, the mechanism of neuroprotection is unclear. Here, we report that blocking PSD‐95 interactions with the Tat‐NR2B9c peptide enhances a Ca2 + ‐dependent protective pathway converging on cAMP Response Element binding protein (CREB) activation. We provide evidence that Tat‐NR2B9c neuroprotection from oxygen glucose deprivation and NMDA toxicity occurs in parallel with the activation of calmodulin kinase signalling and is dependent on a sustained phosphorylation of the CREB transcription factor and its activator CaMKIV. Tat‐NR2B9c‐dependent neuroprotection and CREB phosphorylation are blocked by coapplication of CaM kinase (KN93 and STO‐609) or CREB (KG‐501) inhibitors, and by siRNA knockdown of CaMKIV. These results are mirrored in vivo in a rat model of permanent focal ischaemia. Tat‐NR2B9c application significantly reduces infarct size and causes a selective and sustained elevation in CaMKIV phosphorylation; effects which are blocked by coadministration of KN93. Thus, calcium‐dependent nuclear signalling via CaMKIV and CREB is critical for neuroprotection via NMDAR‐PSD95 blockade, both in vitro and in vivo. This study highlights the importance of maintaining neuronal function following ischaemic injury. Future stroke research should target neurotrophic and pro‐survival signal pathways in the development of novel neuroprotective strategies.
Involvement of Prolactin‐Releasing Peptide in the Activation of Oxytocin Neurones in Response to Food Intake
Authors: Yamashita M. , Takayanagi Y. , Yoshida M. , Nishimori K. , Kusama M. , Onaka T.
Published: January 2013

Food intake activates neurones expressing prolactin‐releasing peptide (PrRP) in the medulla oblongata and oxytocin neurones in the hypothalamus. Both PrRP and oxytocin have been shown to have an anorexic action. In the present study, we investigated whether the activation of oxytocin neurones following food intake is mediated by PrRP. We first examined the expression of PrRP receptors (also known as GPR10) in rats. Immunoreactivity of PrRP receptors was observed in oxytocin neurones and in vasopressin neurones in the paraventricular and supraoptic nuclei of the hypothalamus and in the bed nucleus of the stria terminalis. Application of PrRP to isolated supraoptic nuclei facilitated the release of oxytocin and vasopressin. In mice, re‐feeding increased the expression of Fos protein in oxytocin neurones of the hypothalamus and bed nucleus of the stria terminalis. The increased expression of Fos protein in oxytocin neurones following re‐feeding or i.p. administration of cholecystokinin octapeptide (CCK), a peripheral satiety factor, was impaired in PrRP‐deficient mice. CCK‐induced oxytocin increase in plasma was also impaired in PrRP‐deficient mice. Furthermore, oxytocin receptor‐deficient mice showed an increased meal size, as reported in PrRP‐deficient mice and in CCKA receptor‐deficient mice. These findings suggest that PrRP mediates, at least in part, the activation of oxytocin neurones in response to food intake, and that the CCK–PrRP–oxytocin pathway plays an important role in the control of the termination of each meal.
Cardiovascular Genomics
Authors: Wung Shu‐Fen , Hickey Kathleen T. , Taylor Jacquelyn Y. , Gallek Matthew J.
Published: January 2013

Purpose: This article provides an update on cardiovascular genomics using three clinically relevant exemplars, including myocardial infarction (MI) and coronary artery disease (CAD), stroke, and sudden cardiac death (SCD).

Organizational Construct: Recent advances in cardiovascular genomic research, testing, and clinical implications are presented.

Methods: Genomic nurse experts reviewed and summarized recent salient literature to provide updates on three selected cardiovascular genomic conditions.

Findings: Research is ongoing to discover comprehensive genetic markers contributing to many common forms of cardiovascular disease (CVD), including MI and stroke. However, genomic technologies are increasingly being used clinically, particularly in patients with long QT syndrome (LQTS) or hypertrophic cardiomyopathy (HCM) who are at risk for SCD.

Conclusions: Currently, there are no clinically recommended genetic tests for many common forms of CVD even though direct‐to‐consumer genetic tests are being marketed to healthcare providers and the general public. On the other hand, genetic testing for patients with certain single gene conditions, including channelopathies (e.g., LQTS) and cardiomyopathies (e.g., HCM), is recommended clinically.

Clinical Relevance: Nurses play a pivotal role in cardiogenetics and are actively engaged in direct clinical care of patients and families with a wide variety of heritable conditions. It is important for nurses to understand current development of cardiovascular genomics and be prepared to translate the new genomic knowledge into practice.
Associations of Mothers' Friendship Quality with Adolescents' Friendship Quality and Emotional Adjustment
Authors: Glick Gary C. , Rose Amanda J. , Swenson Lance P. , Waller Erika M.
Published: January 2013

Little research has examined the association of parents' friendships with adolescent's well‐being, perhaps because the association was considered too distal. However, developmental theories suggest that contexts in which parents, but not their children, are situated may be related to child development (Bronfenbrenner,,). The current work examined associations between the quality of mothers' own friendships and their adolescent children's friendship quality and emotional adjustment. Fifth‐, eighth‐, and eleventh‐graders (N = 172) whose mothers' friendships were characterized by conflict and antagonism reported having friendships that were high in negative friendship qualities as well as elevated internalizing symptoms. These associations held after controlling for mother–child relationship quality, suggesting that mothers' friendships may have a unique association with adolescents' adjustment.
Aversive Peer Experiences on Social Networking Sites: Development of the Social Networking‐Peer Experiences Questionnaire (SN‐PEQ)
Authors: Landoll Ryan R. , La Greca Annette M. , Lai Betty S.
Published: January 2013

Cyber victimization is an important research area, yet little is known about aversive peer experiences on social networking sites (SNSs), which are used extensively by youth and host complex social exchanges. Across samples of adolescents (n = 216) and young adults (n = 214), we developed the Social Networking‐Peer Experiences Questionnaire (SN‐PEQ) and examined its psychometric properties, distinctiveness from traditional peer victimization measures, and associations with internalized distress. The SN‐PEQ demonstrated strong factorial invariance and a single‐factor structure that was distinct from other forms of peer victimization. Negative SNS experiences were associated with youths' symptoms of social anxiety and depression, even when controlling for traditional peer victimization. Findings highlight the importance of examining the effects of aversive peer experiences that occur via social media.
Co‐occurring grazing and climate stressors have different effects on the total seed bank when compared to the persistent seed bank
Authors: Espinosa Carlos I. , Luzuriaga Arantzazu L. , de la Cruz Marcelino , Montero Marianne , Escudero Adrián
Published: January 2013

Questions

(1) Does climate amelioration in semi‐arid ecosystems increase seed bank richness and seed density in both total and persistent seed banks? (2) Does herbivory modulate climate effects on soil seed banks? (3) Is this effect mediated by changes in the above‐ground vegetation? (4) To what extent do environmental conditions affect similarity between the total and persistent seed banks, and between above‐ground (vegetation) vs below‐ground (seed bank) community compartments?

Location

Ecuadorian Dry Mountain Scrub Ecosystem.

Methods

Our study was conducted along a climatic gradient (altitude) under two different management conditions: undisturbed and grazed. The effect of grazing, altitude and their interaction on seed abundance and richness of the total and persistent soil seed banks were evaluated with non‐linear mixed models.

Results

Altitude, grazing and their interaction exerted a significant effect on richness and abundance of the total seed bank, but not on the persistent seed bank. At highly stressful climate conditions, differences in species richness between the total and persistent seed banks were small or absent, while at milder environmental conditions the total seed bank showed greater seed species richness and abundance than the persistent one. However, under grazing conditions, species richness in both seed banks was rather similar along the climatic gradient. Relationships in terms of species richness between above‐ground vs below‐ground compartments, shifted from being dominated by the above‐ground component at low altitudes (more stress) to being dominated by the seed bank component at higher elevations (milder conditions). In grazed locations, vegetation and seed bank showed similar species richness throughout the altitudinal gradient.

Conclusions

This study demonstrates that not only climate acted as a key environmental filter on soil seed bank properties, but also that grazing greatly modulated the primary effect of climate. Nevertheless, the effect of climate and grazing was restricted to the total seed bank (the fertility compartment) and no effect was observed in the persistent seed bank (longevity compartment). In this tropical dry scrub, richness and abundance of seeds increased upwards along the altitudinal gradient, most likely because at higher altitudes environmental conditions improve and become more benign for plant development.
North Atlantic Islands with native and alien trees: are there differences in diversity and species‐area relationships?
Authors: Vetaas Ole R. , Vikane Jan H. , Saure Heidi I. , Vandvik Vigdis
Published: January 2013

Questions

Are there differences in species composition and richness between islands that were reforested more than 70 yr ago with the introduced Pinus mugo compared with islands supporting the native Pinus sylvestris? Do the results depend on autocorrelation in geographical space and species ordination space? Species richness is expected to increase as a function of the size of an island; are the responses to island size different between P. mugo and P. sylvestris islands. Does the land‐use history have an impact on the current species composition and richness pattern?

Location

The archipelago is in the oceanic section of the Atlantic bioclimatic zone, west Norway. This archipelago was part of the ancient and widespread treeless heathland found along the European west coast.

Methods

Data on vascular plants were compiled from the forested islands, and their differences in species composition were analysed by ordination. The hypotheses were tested by means of t‐tests and generalized linear models, the spatial component was accounted for by means of Moran's I and spatial autoregression with the moving average approach. This was done both in geographical space and species ordination space.

Results

There are more vascular plants on the islands with introduced P. mugo than on the islands with native P. sylvestris. The latter have rather homogenous undergrowth dominated by bryophytes. This may explain lower richness on islands with native forest and why island size is not correlated with species richness on these islands. In contrast, P. mugo is easily wind‐felled in autumn storms, which keeps rocky microhabitats exposed to air and new forest habitats are created. Species that are associated with the previous land‐use system (grazing) prevail on islands with introduced pine, and thus contribute to higher plant richness.

Conclusions

The difference in species richness and island species–area relationship (ISAR) between P. mugo and P. sylvestris islands may relate to the same underpinning causes. Species from the old land‐use system have survived on P. mugo islands, but not in the late‐successional forest with a more closed canopy that has developed on P. sylvestris islands. Thus habitat and species richness is higher and increases with area on P. mugo islands but not on P. sylvestris islands.
Grazing effects on plant community succession of early‐ and mid‐seral seeded grassland compared to shortgrass steppe
Authors: Milchunas Daniel G. , Vandever Mark W.
Published: January 2013

Questions

Grazing may speed or slow secondary succession, and the direction may depend on seral stage and relative tolerance of native perennial grasses compared with annual invasive species. How does grazing affect succession where undisturbed communities have a long evolutionary history of grazing by native herbivores and are tolerant to livestock grazing?

Location

Shortgrass steppe, North American Great Plains, Colorado (40°49′N, 104°46′W), USA.

Methods

Ungrazed and grazed early‐seral (4–6 yr) and mid‐seral (18–20 yr) seeded fields (Conservation Reserve Program) and traditionally grazed native steppe were compared for effects on plant composition in relation to changes expected from regional succession models.

Results

Recovery towards undisturbed native shortgrass steppe for early‐ and mid‐seral communities, respectively, was 19% and 36% for total vegetation cover, 5% and 21% for planted native species, 10% and 88% for non‐planted native perennial grasses, only 0.2% and 13% for short grasses, and overall dissimilarity in community species compositions was 97% and 68%. In general, grazing effects were neutral or most often not significant in all years and/or were small in overall community magnitude. The early‐seral community displayed more changes indicative of a slowing of succession with grazing (total vegetative and grass basal cover) rather than reducing invasive species (species targeted by timing of grazing), although drought had limited the establishment of grazing‐tolerant short grasses. The mid‐seral community showed more changes consistent with advancing successional recovery with grazing (overall community dissimilarity, forbs, planted native perennial grasses, tall grasses and target species). However, non‐planted native perennial grasses responded negatively to grazing in the mid‐seral community and positively in native shortgrass steppe where outside seed would originate.

Conclusions

Grazing effects on particular functional groups and species were not the same across seral stages, were mixed in terms of speeding or slowing succession, and were generally not large at the community level. Evolutionary history of grazing may serve as a general guide but decisions on whether to graze successional grasslands may best be made after assessing whether tolerant perennial short grass species are significant components. Monitoring may then be necessary to determine species responses in particular community matrixes and effects on subsequent immigration of non‐seeded native perennial species.
Shades of red: bird‐pollinated flowers target the specific colour discrimination abilities of avian vision
Authors: Shrestha Mani , Dyer Adrian G. , Boyd‐Gerny Skye , Wong Bob B. M. , Burd Martin
Published: January 2013

Colour signals are a major cue in putative pollination syndromes. There is evidence that the reflectance spectra of many flowers target the distinctive visual discrimination abilities of hymenopteran insects, but far less is known about bird‐pollinated flowers. Birds are hypothesized to exert different selective pressures on floral colour compared with hymenopterans because of differences in their visual systems.

We measured the floral reflectance spectra of 206 Australian angiosperm species whose floral visitors are known from direct observation rather than inferred from floral characteristics. We quantified the match between these spectra and the hue discrimination abilities of hymenopteran and avian vision, and analysed these metrics in a phylogenetically informed comparison of flowers in different pollination groups.

We show that bird‐visited flowers and insect‐visited flowers differ significantly from each other in the chromatic cues they provide, and that the differences are concentrated near wavelengths of optimal colour discrimination by whichever class of pollinator visits the flowers.

Our results indicate that angiosperms have evolved the spectral signals most likely to reinforce their pollinators' floral constancy (the tendency of individual pollinators to visit flowers of the same species) in communities of similarly coloured floral competitors.
Gamete fertility and ovule number variation in selfed reciprocal F1 hybrid triploid plants are heritable and display epigenetic parent‐of‐origin effects
Authors: Duszynska Dorota , McKeown Peter C. , Juenger Thomas E. , Pietraszewska‐Bogiel Anna , Geelen Danny , Spillane Charles
Published: January 2013

Polyploidy and hybridization play major roles in plant evolution and reproduction. To investigate the reproductive effects of polyploidy and hybridization in Arabidopsis thaliana, we analyzed fertility of reciprocal pairs of F1 hybrid triploids, generated by reciprocally crossing 89 diploid accessions to a tetraploid Ler‐0 line.

All F1 hybrid triploid genotypes exhibited dramatically reduced ovule fertility, while variation in ovule number per silique was observed across different F1 triploid genotypes. These two reproductive traits were negatively correlated suggesting a trade‐off between increased ovule number and ovule fertility. Furthermore, the ovule fertility of the F1 hybrid triploids displayed both hybrid dysgenesis and hybrid advantage (heterosis) effects.

Strikingly, both reproductive traits (ovule fertility, ovule number) displayed epigenetic parent‐of‐origin effects between genetically identical reciprocal F1 hybrid triploid pairs. In some F1 triploid genotypes, the maternal genome excess F1 hybrid triploid was more fertile, whilst for other accessions the paternal genome excess F1 hybrid triploid was more fertile.

Male gametogenesis was not significantly disrupted in F1 triploids. Fertility variation in the F1 triploid A. thaliana is mainly the result of disrupted ovule development. Overall, we demonstrate that in F1 triploid plants both ovule fertility and ovule number are subject to parent‐of‐origin effects that are genome dosage‐dependent.
Cis‐Golgi Cisternal Assembly and Biosynthetic Activation Occur Sequentially in Plants and Algae
Authors: Donohoe Bryon S. , Kang Byung‐Ho , Gerl Mathias J. , Gergely Zachary R. , McMichael Colleen M. , Bednarek Sebastian Y. , Staehelin L. Andrew
Published: January 2013

The cisternal progression/maturation model of Golgi trafficking predicts that cis‐Golgi cisternae are formed de novo on the cis‐side of the Golgi. Here we describe structural and functional intermediates of the cis cisterna assembly process in high‐pressure frozen algae (Scherffelia dubia, Chlamydomonas reinhardtii) and plants (Arabidopsis thaliana, Dionaea muscipula; Venus flytrap) as determined by electron microscopy, electron tomography and immuno‐electron microscopy techniques. Our findings are as follows: (i) The cis‐most (C1) Golgi cisternae are generated de novo from cisterna initiators produced by the fusion of 3–5 COPII vesicles in contact with a C2 cis cisterna. (ii) COPII vesicles fuel the growth of the initiators, which then merge into a coherent C1 cisterna. (iii) When a C1 cisterna nucleates its first cisterna initiator it becomes a C2 cisterna. (iv) C2‐Cn cis cisternae grow through COPII vesicle fusion. (v) ER‐resident proteins are recycled from cis cisternae to the ER via COPIa‐type vesicles. (vi) In S. dubia the C2 cisternae are capable of mediating the self‐assembly of scale protein complexes. (vii) In plants, ∼90% of native α‐mannosidase I localizes to medial Golgi cisternae. (viii) Biochemical activation of cis cisternae appears to coincide with their conversion to medial cisternae via recycling of medial cisterna enzymes. We propose how the different cis cisterna assembly intermediates of plants and algae may actually be related to those present in the ERGIC and in the pre‐cis Golgi cisterna layer in mammalian cells.
Postbuckling Analysis of the Length of Transition Zone in a Buckle Propagating Pipeline
Authors: Xue Jianghong
Published: January 2013

When a buckle is initiated in a pipe subjected to external pressure, it will propagate along the longitudinal direction of the pipe if the external pressure is greater than its buckle propagation pressure. For a steady state condition, the propagation is simply considered as the translation of the buckle along the pipeline. This paper presents a unique approach to determine the length of the transition zone in a buckle propagating pipe by analyzing the mechanism of postbuckling of the pipe subjected to the external pressure. Buckling is considered to occur locally in the shell, spreading over a certain length along the longitudinal axis of the shell. The governing equations are derived from the postbuckling theory. Approximate solutions are obtained from the Ritz method, using a plausible function of the flexural displacement created based on Timoshenko's ring solution of the transverse collapse mode. The postbuckling equilibrium path shows that the pipeline experiences unstable collapse until the two opposite points on the inner surface contact each other. The length of the transition zone is found to be proportional to the ratio of (radius)3/2/(thickness)1/2 and is hardly affected by the material properties. The analysis is performed by comparing the obtained results with well-established predictions.
Detecting Ozone- and Greenhouse Gas–Driven Wind Trends with Observational Data
Authors: Lee Sukyoung , Feldstein Steven B.
Published: January 2013

The Change of Winds

As the combined effects of Antarctic stratospheric ozone depletion and climate warming have forced the westerly surface winds in the Southern Hemisphere to shift toward the pole, mixing between the upper ocean and deeper waters has also changed.

Waugh
et al.

(p.
568
) now show that water originating at the surface at subtropical latitudes is mixing into the deeper ocean at a higher rate than 20 years ago, while the reverse is true for those originating at higher latitudes. The summer westerly winds that blow in the Southern Hemisphere have shifted toward the South Pole over the past several decades, but why?
Lee and Feldstein
(p.
563
) show that greenhouse gas forcing and ozone depletion impart different signatures to wind patterns and conclude that ozone depletion has been responsible for more than half of the observed shift.
Hurdles and Opportunities for Landscape-Scale Restoration
Authors: Menz Myles H. M. , Dixon Kingsley W. , Hobbs Richard J.
Published: January 2013

Gaps in knowledge must be identified, capacities developed, and research translated into policy and practice.
Gut Microbiomes of Malawian Twin Pairs Discordant for Kwashiorkor
Authors: Smith Michelle I. , Yatsunenko Tanya , Manary Mark J. , Trehan Indi , Mkakosya Rajhab , Cheng Jiye , Kau Andrew L. , Rich Stephen S. , Concannon Patrick , Mychaleckyj Josyf C. , Liu Jie , Houpt Eric , Li Jia V. , Holmes Elaine , Nicholson Jeremy , Knights Dan , Ursell Luke K. , Knight Rob , Gordon Jeffrey I.
Published: January 2013

Not Just Wasting

Malnutrition is well known in Malawi, including a severe form—kwashiorkor—in which children do not simply waste away, they also suffer edema, liver damage, skin ulceration, and anorexia.

Smith
et al.

(p.
548
; see the Perspective by

Relman

) investigated the microbiota of pairs of twins in Malawian villages and found notable differences in the composition of the gut microbiota in children with kwashiorkor. In these children, a bacterial species related to
Desulfovibrio
, which has been associated with bowel disease and inflammation, was noticeable. When the fecal flora from either the healthy or the sick twin was transplanted into groups of germ-free mice, the mice that received the kwashiorkor sample started to lose weight, like their human counterpart.
Nuclear Magnetic Resonance Spectroscopy on a (5-Nanometer)
3
Sample Volume
Authors: Staudacher T. , Shi F. , Pezzagna S. , Meijer J. , Du J. , Meriles C. A. , Reinhard F. , Wrachtrup J.
Published: January 2013

Nanoscale NMR with Diamond Defects

Although nuclear magnetic resonance (NMR) methods can be used for spatial imaging, the low sensitivity of detectors limits the minimum sample size. Two reports now describe the use of near-surface nitrogen-vacancy (NV) defects in diamond for detecting nanotesla magnetic fields from very small volumes of material (see the Perspective by

Hemmer

). The spin of the defect can be detected by changes in its fluorescence, which allows proton NMR of organic samples only a few nanometers thick on the diamond surface.

Mamin
et al.

(p.
557
) used a combination of electron spin echoes and pulsed NMR manipulation of the proton spins to detect the very weak fields.

Staudacher
et al.

(p.
561
) measured statistical polarization of a population of about 10
4
spins near the NV center with a dynamical decoupling method.
Serotype Sensitivity of a Lateral Flow Immunoassay for Cryptococcal Antigen
Authors: Gates-Hollingsworth Marcellene A. , Kozel Thomas R.
Published: January 2013

To meet the needs of a global community, an immunoassay for cryptococcal antigen (CrAg) must have high sensitivity for CrAg of all major serotypes. A new immunoassay for CrAg in lateral flow format was evaluated and found to have a high sensitivity for detection of serotypes A, B, C, and D.
Cerebrospinal Fluid (1,3)-β-
d
-Glucan Detection as an Aid for Diagnosis of Iatrogenic Fungal Meningitis
Authors: Lyons Jennifer L. , Roos Karen L. , Marr Kieren A. , Neumann Henry , Trivedi Julie B. , Kimbrough Dorlan J. , Steiner Lisa , Thakur Kiran T. , Harrison Daniel M. , Zhang Sean X.
Published: January 2013

This case series highlights our experience with use of the Fungitell assay for quantifying (1,3)-β-
d
-glucan in cerebrospinal fluid during the current U.S. outbreak of fungal meningitis related to contaminated methylprednisolone acetate. This test may prove a useful adjunct in diagnosis and management of exposed patients.
Whole-Genome Mapping: a New Paradigm in Strain-Typing Technology
Authors: Miller J. Michael
Published: January 2013

Strain-typing technology in support of outbreak identification and resolution has evolved from phenotypic analysis, such as serology and biotypes, to much-more-robust molecular genetic approaches, such as pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing. Whole-genome mapping (WGM) has been recently applied to subtyping analysis, and it bridges the gap between PFGE (∼20 bands sorted by size) and whole-genome sequencing. WGM utilizes restriction site analysis but arranges 200 to 500 bands in the order they appear on the chromosome. WGM is able to quickly and cost-effectively generate high-resolution, ordered whole-genome maps of bacteria.
Direct Sequencing and RipSeq Interpretation as a Tool for Identification of Polymicrobial Infections
Authors: Wolff Tine Y. , Eickhardt Steffen , Björnsdottir Maria K. , Moser Claus , Bjarnsholt Thomas , Høiby Niels , Thomsen Trine R.
Published: January 2013

In this study, RipSeq Mixed, a software resolving uninterpretable mixed DNA sequencing chromatograms, revealed the bacterial content of 15 polymicrobial samples. Direct sequencing combined with RipSeq Mixed constitutes a valuable supplement to cultivation, particularly when cultivation is negative and direct sequencing is inconclusive despite continued clinical indications of infection.
Comparison of (1→3)-β-
d
-Glucan, Mannan/Anti-Mannan Antibodies, and Cand-Tec Candida Antigen as Serum Biomarkers for Candidemia
Authors: Held Jürgen , Kohlberger Isabelle , Rappold Elfriede , Busse Grawitz Andrea , Häcker Georg
Published: January 2013

We conducted a case-control study using the Fungitell assay, the novel Platelia
Candida
Antigen (Ag) Plus and
Candida
Antibody (Ab) Plus assays, and the Cand-Tec latex agglutination test to evaluate the usefulness of (1→3)-β-
d
-glucan (BDG), mannan antigen with/without anti-mannan antibody, and Cand-Tec
Candida
antigen measurement for the diagnosis of candidemia. A total of 56 patients fulfilled the inclusion criteria and were enrolled. One hundred patients with bacteremia and 100 patients with sterile blood cultures served as negative controls. In the candidemia group, median (1→3)-β-
d
-glucan, mannan antigen, and anti-mannan antibody levels were 427 pg/ml, 190 pg/ml, and 18.6 antibody units (AU)/ml, respectively. All three parameters were significantly elevated in patients with candidemia. The sensitivity and specificity were, respectively, 87.5% and 85.5% for (1→3)-β-
d
-glucan, 58.9% and 97.5% for mannan antigen, 62.5% and 65.0% for anti-mannan antibody, 89.3% and 63.0% for mannan antigen plus anti-mannan antibody, 89.3% and 85.0% for BDG plus mannan antigen, and 13.0% and 93.9% for Cand-Tec
Candida
antigen. The low mannan antigen sensitivity was in part caused by
Candida parapsilosis
and
Candida guilliermondii
fungemias, which were not detected by the Platelia
Candida
Ag Plus assay. When the cutoff was lowered from 125 pg/ml to 50 pg/ml, mannan antigen sensitivity increased to 69.6% without severely affecting the specificity (93.5%). Contrary to recently published data, superficial candidiasis was not associated with elevated mannan antigen levels, not even after the cutoff was lowered. Combining procalcitonin (PCT) with (1→3)-β-
d
-glucan to increase specificity provided a limited advantage because the benefit of the combination did not outweigh the loss of sensitivity. Our results demonstrate that the Cand-Tec
Candida
antigen and the mannan antigen plus anti-mannan antibody measurements have unacceptably low sensitivity or specificity. Of the four tests compared, (1→3)-β-
d
-glucan and mannan antigen are the superior biomarkers, depending on whether a sensitivity-driven or specificity-driven approach is used.
Invasive Pulmonary Aspergillosis Due to Emericella nidulans var. echinulata, Successfully Cured by Voriconazole and Micafungin
Authors: Yu Jin , Mu Xiangdong , Li Ruoyu
Published: January 2013

A 78-year-old male who was undergoing prolonged glucocorticoid treatment experienced cough and expectoration for 2 weeks. Galactomannan antigen analysis and a chest computed tomography (CT) scan suggested a diagnosis of invasive pulmonary aspergillosis. DNA sequencing indicated that
Emericella nidulans
var.
echinulata
was the causative agent. A combination of voriconazole and micafungin successfully treated the illness.
Comparison of Anyplex II RV16 with the xTAG Respiratory Viral Panel and Seeplex RV15 for Detection of Respiratory Viruses
Authors: Kim Hyun-Ki , Oh Sung-Hee , Yun Kyung Ah , Sung Heungsup , Kim Mi-Na
Published: January 2013

A novel multiplex real-time PCR approach (Anyplex II RV16 [RV16]; Seegene, South Korea) was compared with a multiplex endpoint PCR kit (Seeplex RV15 ACE detection kit [RV15]; Seegene) and a liquid bead-based assay (xTAG respiratory viral panel [xTAG]; Abbott, United States). Of nasopharyngeal swabs or aspirates and bronchoalveolar lavage fluid samples submitted for RV15 testing, 199 retrospectively collected positive specimens and 283 prospectively collected specimens were further tested with RV16 and xTAG. A true-positive result was defined as a positive result from all three methods or RV16 and xTAG or RV15 and xTAG. For specimens with discrepant results, monoplex PCR and sequencing of the target viruses were performed. In total, 300 virus-positive specimens yielded 386 viruses. When the bocavirus results were excluded, the overall sensitivities of RV16, RV15, and xTAG were 95.2%, 93.3%, and 87.2%, respectively (95% confidence intervals, 93.0 to 97.4%, 90.8 to 95.8%, and 83.8 to 90.6%, respectively). RV16 was more sensitive than xTAG for coronavirus OC43/HKU1 (100% versus 26.1%;
P
< 0.0001) and adenovirus (100% versus 79.5%;
P
< 0.01) but was less sensitive than xTAG for rhinovirus/enterovirus (89.4% versus 97.9%;
P
< 0.05). RV16 demonstrated higher sensitivity than RV15 for the detection of adenovirus (100% versus 82.1%;
P
< 0.05). The specificities of all three methods ranged from 98.6% to 100%. Sequencing analysis of 64 rhinovirus-positive samples revealed that RV16 accurately differentiated between rhinovirus and enterovirus. RV16 most frequently missed rhinovirus C. In conclusion, the overall sensitivity of RV16 was better than that of xTAG. However, improvement of the sensitivity for rhinovirus is required.
A Deceptive Case of Cellulitis Caused by a Gram-Negative Pathogen
Authors: Bhowmick T. , Weinstein M. P.
Published: January 2013

Yokenella regensburgei
is a member of the family
Enterobacteriaceae
that has rarely been implicated in clinical disease. We report here a case of septicemia with a skin and soft tissue source caused by
Y. regensburgei
in an immunocompromised host.
Evaluation of a Microarray-Based Assay for Rapid Identification of Gram-Positive Organisms and Resistance Markers in Positive Blood Cultures
Authors: Samuel Linoj P. , Tibbetts Robert J. , Agotesku Adam , Fey Margaret , Hensley Rhonda , Meier Frederick A.
Published: January 2013

Rapid identification of pathogens directly from positive blood cultures can play a major role in reducing patient mortality rates. We evaluated the performance of the Verigene Gram-Positive Blood Culture (BC-GP) assay (Nanosphere Inc., Northbrook, IL) for detection of commonly isolated Gram-positive organisms as well as associated resistance markers from positive blood cultures. Positive blood cultures (VersaTREK; Trek Diagnostic Systems, Independence, OH) from 203 patients with Gram-positive organism infections were analyzed using the BC-GP assay within 12 h for the detection of 12 different organisms, including staphylococci, streptococci, and enterococci, as well as for the presence of 3 resistance markers (
mecA
,
vanA
, and
vanB
). Results were compared to those of routine laboratory methods for identification and susceptibility testing. For identification of organisms and detection of resistance markers in 178 monomicrobial positive blood cultures, the BC-GP assay showed 94% and 97% concordance, respectively, with routine methods. After 25 polymicrobial cultures were included, the results showed 92% and 96% agreement for identification and resistance markers, respectively, for a total of 203 positive cultures. In 6/25 polymicrobial cultures, at least 1 isolate was not detected. Concordance levels for detection of major pathogens such
Staphylococcus aureus
(
n
= 45) and enterococci (
n
= 19) were 98% and 95%, respectively. Agreement levels for detection of resistance markers such as
mecA
and
vanA
/
B
were 92% and 100%, respectively. The BC-GP assay is capable of providing rapid identification of Gram-positive cocci as well as detection of resistance markers directly from positive blood cultures at least 24 to 48 h earlier than conventional methods.
Prevalence and Characterization of Methicillin-Resistant Staphylococcus aureus Isolates from Retail Meat and Humans in Georgia
Authors: Jackson Charlene R. , Davis Johnnie A. , Barrett John B.
Published: January 2013

There is increasing interest in the presence of
Staphylococcus aureus
, specifically methicillin-resistant
S. aureus
(MRSA), on retail meat products. In this study, staphylococci were isolated from retail pork and retail beef in Georgia, and MRSA from the products was compared to human MRSA from the same geographic area using broth microdilution antimicrobial susceptibility testing, multilocus sequence typing (MLST),
spa
typing, SCC
mec
typing, and pulsed-field gel electrophoresis (PFGE).
S. aureus
was isolated from 45% (45/100) of pork products and 63% (63/100) of beef products;
mecA
was detected in
S. aureus
from both pork (3/100; 3%) and beef (4/100; 4%). Fifty percent (50/100) of human
S. aureus
also contained
mecA
. Multidrug resistance was detected among MRSA from all sources. All MRSA (
n
= 57) was SCC
mec
type IV, and nine different
spa
types were present among the isolates (t002, t008, t012, t024, t179, t337, t548, t681, and t1062). Four sequence types (ST5, ST8, ST9, and ST30) were detected using MLST; the majority of MRSA isolates belonged to ST8, followed by ST5. One retail beef MRSA isolate belonged to ST8, while the remaining three were ST5. In retail pork MRSA, ST5, ST9, and ST30 were observed. The majority of human MRSA isolates belonged to ST8. Thirty-seven MRSA isolates, one of which was a retail beef MRSA isolate, were
pvl
+
. Using PFGE, MLST, and
spa
typing, three retail beef MRSA isolates were found to be identical in PFGE pattern, ST, and
spa
type to two human clonal MRSA isolates (USA100 and USA300). One additional retail beef MRSA isolate had a PFGE pattern similar to that of a human MRSA isolate, whereas none of the retail pork MRSA isolates had PFGE patterns similar to those of human MRSA isolates. These data suggest that the retail beef samples were contaminated by a human source, possibly during processing of the meat, and may present a source of MRSA for consumers and others who handle raw meat.
Evaluation of an Algorithmic Approach in Comparison with the Illumigene Assay for Laboratory Diagnosis of Clostridium difficile Infection
Authors: Walkty A. , Lagacé-Wiens P. R. S. , Manickam K. , Adam H. , Pieroni P. , Hoban D. , Karlowsky J. A. , Alfa M.
Published: January 2013

The following three diagnostic algorithms were evaluated in comparison with the Illumigene assay as a stand-alone test for
Clostridium difficile
detection: glutamate dehydrogenase antigen screen (GDH) followed by toxin A/B antigen testing (Tox A/B) with the cell cytotoxicity assay for discordant specimens (algorithm 1), GDH followed by the Illumigene (algorithm 2), and GDH followed by Tox A/B with the Illumigene for discordant specimens (algorithm 3). A total of 428 stool specimens submitted to three clinical microbiology laboratories in Manitoba, Canada, for
C. difficile
detection between June 2011 and April 2012 were included in the study. The prevalence of
C. difficile
in the stool specimens was 14.7% (63/428) based on toxigenic culture (microbiologic reference standard). The sensitivity and specificity of the Illumigene for
C. difficile
detection were 73.0% and 99.7%, respectively. The corresponding sensitivities and specificities were 65.1% and 100.0% for algorithm 1, 68.3% and 100.0% for algorithm 2, and 69.8% and 100.0% for algorithm 3. Using algorithm 1, a cell cytotoxicity assay was required for toxin detection in 37% of positive tests, prolonging turnaround time. However, the predictive value of a positive test based on a clinical reference standard (all tests positive or cytotoxigenic culture positive and clinical disease on chart review) was slightly higher with algorithm 1 than with the Illumigene assay as a stand-alone test or as part of an algorithm (algorithms 2 and 3). Based on a reduction in turnaround time, simplicity, and acceptable sensitivity and specificity, we recommend algorithm 2 (screening with the GDH antigen test and confirmatory testing with the Illumigene).
Ciprofloxacin-Resistant Aeromonas hydrophila Cellulitis following Leech Therapy
Authors: Giltner Carmen L. , Bobenchik April M. , Uslan Daniel Z. , Deville Jaime G. , Humphries Romney M.
Published: January 2013

We report a case of surgical site infection with ciprofloxacin-resistant
Aeromonas hydrophila
following leech therapy. Antimicrobial and genetic analyses of leech and patient isolates demonstrated that the resistant isolates originated from the leech gut microbiota. These data suggest that ciprofloxacin monotherapy as a prophylaxis regimen prior to leech therapy may not be effective in preventing infection.