bluuebunny/crossref_metadata_2025 huggingface dataset:
Enteric glial cells are associated with stress‐induced colonic hyper‐contraction in maternally separated rats
Authors: Fujikawa Y. , Tominaga K. , Tanaka F. , Tanigawa T. , Watanabe T. , Fujiwara Y. , Arakawa T.
Published: May 2015

Background

Enteric glial cells (EGCs) play important roles in enteric integrity and regulation of gastrointestinal function. However, whether EGCs undergo pathophysiological changes in stress‐associated gastrointestinal disorders is unknown. We investigated structural and functional alterations in colonic EGCs and their roles in colonic contraction in an irritable bowel syndrome (IBS) model.

Methods

As a chronic stress, male Wistar rats underwent 3‐h maternal separation during postnatal days 2–14. As an acute stress, we used water‐immersion stress (4 h) in adulthood (at 8 weeks). We quantitatively and morphologically evaluated enteric neurons and EGCs using whole‐mount longitudinal muscle‐myenteric plexus preparations. Colonic contraction was analyzed with electrical field stimulation (EFS).

Key Results

Glial fibrillary acidic protein (GFAP) expression and the number of total, cholinergic, and nitrergic neurons were unchanged in maternally separated rats with acute stress (combined stress: an IBS model) compared with controls. However, the density of GFAP‐positive EGC processes that apparently overlapped with the neurons and the extent of bulbous swelling of terminals increased according to the stress intensity: control, acute stress, maternal separation, and combined stress. EFS‐induced colonic contractions were significantly greater in the combined stress rats than in controls. Higher dose of fluorocitrate, a selective inhibitor of EGC metabolism, was required to inhibit both EFS‐induced contraction and EGCs activation in the combined stress rats than in controls.

Conclusions & Inferences

Colonic EGCs exhibited structural alterations according to the stress intensity. EGCs were associated with stress‐induced colonic hyper‐contraction in the combined stress rats, which may underlie the pathogenesis of IBS.
Clinical relevance of echocardiogram in patients with cerebral palsy undergoing posterior spinal fusion
Authors: DiCindio Sabina , Arai Lynda , McCulloch Michael , Sadacharam Kesavan , Shah Suken A. , Gabos Peter , Dabney Kirk , Theroux Mary C.
Published: May 2015

Background

Spinal deformity is one of the secondary musculoskeletal problems that occur with cerebral palsy (CP). Of the co morbidities associated with CP and spinal deformity, cardiac function is of theoretical concern.

Objective

The goal of our study was to determine the clinical relevance of routine preoperative cardiology evaluation via echocardiogram for patients with CP presenting for posterior spine fusion (PSF) surgery.

Methods

A retrospective chart review was performed of CP patients presenting for scoliosis surgery. The data collected for each patient included: age, sex, height, weight, Cobb angle, and medical history. All patients had a preoperative cardiac evaluation.

Results

Seventy‐two patients were included. The mean age was 13.6 ± 3.4 years. Left ventricular systolic function was normal in all patients; the mean shortening fraction was 39.3 ± 6.2%. No patient had more than mild insufficiency of either the semilunar or atrioventricular valve. One patient was diagnosed with aortic root dilation as well as aortic valve insufficiency. All patients had PSF surgery without changes in anesthetic or surgical plans, and no patient experienced complications attributable to a cardiac origin.

Conclusion

The results suggest that routine preoperative cardiology evaluation via echocardiogram for children with CP in the absence of clinical history or physical examination findings suggestive of cardiac disease is not necessary.
Revisiting a measure of child postoperative recovery: development of the Post Hospitalization Behavior Questionnaire for Ambulatory Surgery
Authors: Jenkins Brooke N. , Kain Zeev N. , Kaplan Sherrie H. , Stevenson Robert S. , Mayes Linda C. , Guadarrama Josue , Fortier Michelle A.
Published: May 2015

Background

The Post Hospitalization Behavior Questionnaire (PHBQ) was designed for assessing children's posthospitalization and postoperative new‐onset behavioral changes. However, the psychometric properties of the scale have not been re‐evaluated in the past five decades despite substantial changes in the practice of surgery and anesthesia. In this investigation, we examined the psychometric properties of the PHBQ to potentially increase the efficacy and relevance of the instrument in current perioperative settings.

Method

This study used principal components analysis, a panel of experts, Cronbach's alpha, and correlations to examine the current subscale structure of the PHBQ and eliminate items to create the Post Hospitalization Behavior Questionnaire for Ambulatory Surgery (PHBQ‐AS). Data from previous investigations (N = 1064, Mage = 5.88) which utilized the PHBQ were combined for the purposes of this paper.

Results

A principal components analysis revealed that the original subscale structure of the PHBQ could not be replicated. Subsequently, a battery reduction, which utilized principal components analysis and a panel of experts, was used to eliminate the subscale structure of the scale and reduce the number of items from 27 to 11, creating the PHBQ‐AS. The PHBQ‐AS demonstrated good internal consistency reliability and concurrent validity with another measure of children's psychosocial and physical functioning.

Conclusion

Revising the former subscale structure and reducing the number of items in the PHBQ to create the PHBQ‐AS may provide a means for reducing the burden of postoperative behavioral assessment through decreasing time of administration and eliminating redundancy of items and allow for more accurate measurement of child postoperative behavioral changes.
Continuous minimally invasive cardiac output monitoring with the COstatus in a neonatal swine model: recalibration is necessary during vasoconstriction and vasodilation
Authors: Cisternas Alvaro F. , Martin‐Flores Manuel , Gleed Robin D.
Published: May 2015

Background

The COstatus monitor measures cardiac output via the transpulmonary ultrasound dilution method (COTPUD) after injection of normal saline, and can calculate continuous cardiac output (CCO) from the arterial pressure waveform. The relationship between arterial waveform and COTPUD however, might be degraded during vasoconstriction/vasodilation.

Objectives

To examine if recalibration of arterial waveform‐derived CCO is required during mild vasoconstriction/vasodilation.

Methods

In 10 anesthetized piglets (6.6–10.1 kg), two COstatus monitors calculated the CCO from the same femoral arterial waveform before and during infusions of phenylephrine (PE; 1 or 3 mg·kg−1·min−1) and sodium nitroprusside (SNP; 1 or 5 mg·kg−1·min−1), administered in random order. One monitor was recalibrated (CCORecal) after each intervention, while the other monitor was not (CCONon‐Recal). Recalibration was performed with COTPUD with 1 ml·kg−1 normal saline as indicator. The effects of each infusion on hemodynamic parameters were compared with baseline using paired t‐tests. The bias, limits of agreement (LOA), and percentage error between simultaneous measurements (CCORecal and CCONon‐Recal) were examined with Bland–Altman plots.

Results

Infusion of PE significantly increased COTPUD, heart rate (HR), and arterial pressures but not systemic vascular resistance (SVR). Infusion of SNP decreased arterial pressures without affecting COTPUD, HR, and SVR. There was no bias between CCORecal and CCONon‐Recal at the baseline, but a small bias was observed during PE and SNP infusions. The LOA increased approximately 10 fold during vasoconstriction and vasodilation. The percentage error increased from ≤ 5% to 32% and 27% during PE and SNP infusions, respectively.

Conclusion

Continuous cardiac output (CO) measured with the COstatus monitor requires recalibration during vasoconstriction and vasodilation, even if changes in COTPUD or SVR are not substantial.
Achieving Transparency: An Argument For Enactivism
Authors: Ward Dave
Published: May 2015

The transparency of perceptual experience has been invoked in support of many views about perception. I argue that it supports a form of enactivism—the view that capacities for perceptual experience and for intentional agency are essentially interdependent. I clarify the perceptual phenomenon at issue, and argue that enactivists should expect to find a parallel instance of transparency in our agentive experience, and that the two forms of transparency are constitutively interdependent (Section 1). I then argue that i) we do indeed find such parallels: the way in which an action is directed towards its goal through our bodily movements parallels the way in which an experience is directed towards its object through our perceptual sensation (Section 2), and ii) reflecting on sensorimotor skills shows why the two instances of transparency are constitutively interdependent (Section 3). Section 4 gives reasons for generalizing beyond the cases considered so far by applying the enactive view to Kohler's landmark studies of perceptual adaptation. The final section clarifies the form of enactivism to which the previous sections point. The view that emerges is one whereby our perceptual and practical skills are interrelated aspects of a single capacity to have one's mind intentionally directed upon the world. The transparency of experience, on this view, is achieved in virtue of our capacities as agents as much as it is given in virtue of our capacities as perceivers.
Effects of water turbulence on variations in cell ultrastructure and metabolism of amino acids in the submersed macrophyte, Elodea nuttallii (Planch.) H. St. John
Authors: Atapaththu K. S. S. , Miyagi A. , Atsuzawa K. , Kaneko Y. , Kawai‐Yamada M. , Asaeda T.
Published: May 2015

The interactions between macrophytes and water movement are not yet fully understood, and the causes responsible for the metabolic and ultrastructural variations in plant cells as a consequence of turbulence are largely unknown. In the present study, growth, metabolism and ultrastructural changes were evaluated in the aquatic macrophyte Elodea nuttallii, after exposure to turbulence for 30 days. The turbulence was generated with a vertically oscillating horizontal grid. The turbulence reduced plant growth, plasmolysed leaf cells and strengthened cell walls, and plants exposed to turbulence accumulated starch granules in stem chloroplasts. The size of the starch granules increased with the magnitude of the turbulence. Using capillary electrophoresis–mass spectrometry (CE‐MS), analysis of the metabolome found metabolite accumulation in response to the turbulence. Asparagine was the dominant amino acid that was concentrated in stressed plants, and organic acids such as citrate, ascorbate, oxalate and γ‐amino butyric acid (GABA) also accumulated in response to turbulence. These results indicate that turbulence caused severe stress that affected plant growth, cell ultrastructure and some metabolic functions of E. nuttallii. Our findings offer insights to explain the effects of water movement on the functions of aquatic plants.
Biochemical and physiological processes associated with the differential ozone response in ozone‐tolerant and sensitive soybean genotypes
Authors: Chutteang C. , Booker F. L. , Na‐Ngern P. , Burton A. , Aoki M. , Burkey K. O.
Published: May 2015

Biochemical and physiological traits of two soybean [Glycine max (L.) Merr.] genotypes differing in sensitivity to ozone (O3) were investigated to determine the possible basis for the differential response. Fiskeby III (O3‐tolerant) and Mandarin (Ottawa) (O3‐sensitive) were grown in a greenhouse with charcoal‐filtered air for 4 weeks, then treated with O3 for 7 h·day−1 in greenhouse chambers. Mandarin (Ottawa) showed significantly more leaf injury and hydrogen peroxide (H2O2) and superoxide (O2−) production compared with Fiskeby III. Peroxidase activity in Mandarin (Ottawa) was 31% higher with O3 but was not significantly different in Fiskeby III. Ozone did not affect superoxide dismutase or glutathione reductase activities, or leaf concentrations of glutathione or ascorbic acid. Thus, variation in O3 response between Fiskeby III and Mandarin (Ottawa) was not explained by differences in antioxidant enzymes and metabolites tested. Ethylene emission from leaves declined in Fiskeby III following O3 exposure but not in Mandarin (Ottawa). Ozone exposure reduced quantum yield (ΦPSII), electron transport rate (ETR) and photochemical quenching (qp) in Mandarin (Ottawa) more than in Fiskeby III, indicating that efficiency of energy conversion of PSII and photosynthetic electron transport was altered differently in the two genotypes. Short‐term exposure to O3 had minimal effects on net carbon exchange rates of both soybean cultivars. A trend toward higher stomatal conductance in Mandarin (Ottawa) suggested stomatal exclusion might contribute to differential O3 sensitivity of the two genotypes. Increased sensitivity of Mandarin (Ottawa) to O3 was associated with higher H2O2 and O2− production compared with Fiskeby III, possibly associated with genotype differences in stomatal function or regulation of ethylene during the initial phases of O3 response.
Nitrogen assimilation and transpiration: key processes conditioning responsiveness of wheat to elevated [CO2] and temperature
Authors: Jauregui Iván , Aroca Ricardo , Garnica María , Zamarreño Ángel M. , García‐Mina José M. , Serret Maria D. , Parry Martin , Irigoyen Juan J. , Aranjuelo Iker
Published: May 2015

Although climate scenarios have predicted an increase in [CO2] and temperature conditions, to date few experiments have focused on the interaction of [CO2] and temperature effects in wheat development. Recent evidence suggests that photosynthetic acclimation is linked to the photorespiration and N assimilation inhibition of plants exposed to elevated CO2. The main goal of this study was to analyze the effect of interacting [CO2] and temperature on leaf photorespiration, C/N metabolism and N transport in wheat plants exposed to elevated [CO2] and temperature conditions. For this purpose, wheat plants were exposed to elevated [CO2] (400 vs 700 µmol mol−1) and temperature (ambient vs ambient + 4°C) in CO2 gradient greenhouses during the entire life cycle. Although at the agronomic level, elevated temperature had no effect on plant biomass, physiological analyses revealed that combined elevated [CO2] and temperature negatively affected photosynthetic performance. The limited energy levels resulting from the reduced respiratory and photorespiration rates of such plants were apparently inadequate to sustain nitrate reductase activity. Inhibited N assimilation was associated with a strong reduction in amino acid content, conditioned leaf soluble protein content and constrained leaf N status. Therefore, the plant response to elevated [CO2] and elevated temperature resulted in photosynthetic acclimation. The reduction in transpiration rates induced limitations in nutrient transport in leaves of plants exposed to elevated [CO2] and temperature, led to mineral depletion and therefore contributed to the inhibition of photosynthetic activity.
Effect of Sildenafil on Pre‐Eclampsia‐Like Mouse Model Induced By L‐Name
Authors: Motta C , Grosso C , Zanuzzi C , Molinero D , Picco N , Bellingeri R , Alustiza F , Barbeito C , Vivas A , Romanini MC
Published: May 2015

Contents

N(omega)‐nitro‐L‐arginine methyl ester (L‐NAME) decreases the vasodilator effect of nitric oxide (NO) and induces pre‐eclampsia in mouse. Sildenafil inhibits the degradation of nitric oxide and increases vasodilation. This study aimed to determine the effects of sildenafil citrate on angiogenesis and oxidative stress at the maternal foetal interface on pre‐eclampsia‐like mouse model induced byL‐NAME. Twenty pregnant mice were divided into four groups: (i) vehicle control; (ii)L‐NAME; (iii) sildenafil; (4)L‐NAME+sildenafil.L‐NAMEwas administered from day 7 of pregnancy and sildenafil from day 8 until day 16; animals were euthanized on day 17. Placental and foetal sizes and weights were measured; lipid peroxide levels and catalase activity in placental homogenates were determined, and placental vascular endothelia were identified by lectin‐histochemistry usingBSA‐Ilectin. Western blot analysis was used to determineVEGFexpression in placental homogenates. No changes were seen in placental and foetal development in mice with normal pregnancies treated with sildenafil. Treatments withL‐NAMEreduced significantly the placental weight and average height and decreased the percentage of the endothelial surface. These alterations may be mediated by the reduction ofNOlevels in trophoblastic cells, due to the inhibitory effect ofL‐NAMEon nitric oxide synthase (NOS) synthesis. This effect was offset by the treatment with sildenafil, with an increase in the percentage of the endothelial surface. In conclusion, our results indicate that treatment with sildenafil on pre‐eclampsia mouse model can be used without adverse effects on the concept and its use in the treatment of pre‐eclampsia is promising.
Measuring Core Inflation inSouthAfrica
Authors: du Plessis Stan , du Rand Gideon , Kotzé Kevin
Published: May 2015

Measures of core inflation convey critical information about an economy. They have a direct effect on the policymaking process, particularly in inflation‐targeting countries, and are utilised in forecasting and modelling exercises. In South Africa, the price indices on which inflation is based have been subject to important structural breaks following changes to the underlying basket of goods and the methodology for constructing price indices. This paper seeks to identify a consistent measure of core inflation for South Africa using trimmed means estimates, measures that exclude changes in food and energy prices, dynamic factor models, and wavelet decompositions. After considering the forecasting ability of these measures, which provide an indication of expected second‐round inflationary effects, traditional in‐sample criteria were used for further comparative purposes. The results suggest that wavelet decompositions provide a useful measure of this critical variable.
Evaluation of accelerated corneal collagen cross‐linking for the treatment of bullous keratopathy in eight dogs (10 eyes)
Authors: Famose Frank
Published: May 2015

Objective

Bullous keratopathy (BK) is a serious corneal condition leading to impaired vision and ocular pain, due to chronic corneal edema and recurrent superficial ulceration. BK is refractory to conventional therapy. In human patients, corneal collagen cross‐linking (CXL) has been used for the treatment of BK, and CXL treatment was recently described for canine patients. The aim of this study was to evaluate the clinical and pachymetric effects of accelerated CXL in dogs affected by BK.

Animal studied

Eight dogs (10 eyes) with BK underwent accelerated CXL.

Procedures

CXL treatment comprised 30 min of riboflavin–dextran instillation, followed by 3 min of UVA irradiation at 30 mW/cm². Ocular pain, corneal edema, corneal ulceration, and pachymetry were evaluated 7, 14, 30, 90, and 180 days after treatment.

Results

Corneal ulceration and ocular pain were resolved by 1 week after CXL treatment and did not recur during the 6‐month follow‐up period. Corneal edema improved in the first 3 months, but worsened from months 3 to 6. Corneal thickness initially decreased, but returned to baseline by 6 months post‐CXL.

Conclusions

CXL is a useful treatment option for BK in dogs, despite the short‐lasting effects on corneal thickness. Patient comfort improved rapidly after a single procedure, although CXL did not achieve resolution of corneal edema. Treatment protocols may be refined to produce more durable effects on corneal edema.
Using the age shift method to determine gains from weed management for Pinus radiata in New Zealand
Authors: Watt M S , Rolando C A , Kimberley M O , Coker G W R
Published: May 2015

Understanding the effects of interspecific competition on long‐term growth of plantation forestry crops is critical to forest management decisions around methods used for weed control. A series of permanent sample plots (31) incorporating trees maintained either weedy or weed‐free until canopy closure were established across New Zealand between 2000 and 2002. We used the age shift method to characterise growth responses of Pinus radiata, in New Zealand, to interspecific competition over the first third of a typical rotation. Eight years after planting, age shifts between treatments ranged between −0.60 years and +3.07 years. On average, the age shift due to weed control increased from 0.62 to 0.96 years between 4 and 8 years of age. This was due to divergent tree growth between weedy and weed‐free plots at 55% of the sites, while at 32% and 13% of sites, respectively, differences between treatments remained constant or decreased beyond age 4 years. The magnitude of the age shift was found to be related to the type of weed dominating early interspecific competition, with woody weeds associated with significantly greater age shifts. Continued divergence in tree growth between weedy and weed‐free treatments up to 8 years after planting at the majority of sites was an unexpected result and contrasts with previous literature. In situations where growth divergence continues beyond 2 years, managers should consider continued treatment of weeds to mitigate the detrimental impacts of on‐going competition.
The biogeography and phylogeny of schizothoracine fishes (Schizopygopsis) in the Qinghai‐Tibetan Plateau
Authors: Qi Delin , Guo Songchang , Chao Yan , Kong Qinghui , Li Changzhong , Xia Mingzhe , Xie Baosheng , Zhao Kai
Published: May 2015

Freshwater fish belonging to the genus Schizopygopsis are widespread in drainages throughout the Qinghai‐Tibetan Plateau and, thus, a model group with which to investigate how paleo‐drainage changes linked to historical uplifting within the Qinghai‐Tibetan Plateau influence speciation. To date, the phylogenetic and taxonomic relationships within Schizopygopsis remain controversial. In this study, we constructed a comprehensive molecular phylogeny of Schizopygopsis based on six mitochondrial gene sequences. We compared the taxonomic relationships revealed by this phylogeny with those obtained from morphological data. We also used this phylogeny to assess the extent to which the evolution of Schizopygopsis has been driven by paleo‐drainage changes linked to uplifting of the Qinghai‐Tibetan Plateau. Results indicated that all Schizopygopsis taxa formed a monophyletic group comprising five major clades, which were inconsistent with the taxonomic relationships based on morphology for this group. Our results also strongly supported the validity of S. anteroventris and S. microcephalus as distinct species within Schizopygopsis. Molecular calibrations showed that species within the middle Yangtze species diverged earlier (~4.5 Mya) than species within the Indus River (~3.0 Mya), the Mekong River (~2.8 Mya) and the Tsangpo + Salween rivers (~2.5 Mya). The most recent evolutionary splits occurred among species from the upper and lower Yangtze River, the Yellow River and the Qiadam Basin at about 1.8 to 0.3 Mya. Our molecular evidence and use of the molecular clock calibration have allowed us to associate speciation events within the genus Schizopygopsis to the formation and separation of paleo‐drainage connections caused by tectonic events during the uplifting of the Qinghai‐Tibetan Plateau (~4.5 Mya). This work underlines the dominant role of vicariance in shaping the evolutionary history of the genus Schizopygopsis. Further research using multiple loci and more extensive sampling will reveal a more complete picture of the phylogenetic relationships and biogeography of Schizopygopsis fishes.
Therapy using implanted organic bioelectronics
Authors: Jonsson Amanda , Song Zhiyang , Nilsson David , Meyerson Björn A. , Simon Daniel T. , Linderoth Bengt , Berggren Magnus
Published: May 2015

Implanted organic bioelectronics provide possible alternative to existing pain treatments.
Curious kinetic behavior in silica polymorphs solves seifertite puzzle in shocked meteorite
Authors: Kubo Tomoaki , Kato Takumi , Higo Yuji , Funakoshi Ken-ichi
Published: May 2015

High-pressure experiments have revealed that seifertite metastably forms at much lower pressures than previously thought.
Structure of the mycobacterial ATP synthase F
o
rotor ring in complex with the anti-TB drug bedaquiline
Authors: Preiss Laura , Langer Julian D. , Yildiz Özkan , Eckhardt-Strelau Luise , Guillemont Jérôme E. G. , Koul Anil , Meier Thomas
Published: May 2015

Structure and inhibition mechanism of the anti-TB drug bedaquiline bound to the ATP synthase rotor from Mycobacteria.
Radially oriented mesoporous TiO
2
microspheres with single-crystal–like anatase walls for high-efficiency optoelectronic devices
Authors: Liu Yong , Che Renchao , Chen Gang , Fan Jianwei , Sun Zhenkun , Wu Zhangxiong , Wang Minghong , Li Bin , Wei Jing , Wei Yong , Wang Geng , Guan Guozhen , Elzatahry Ahmed A. , Bagabas Abdulaziz A. , Al-Enizi Abdullah M. , Deng Yonghui , Peng Huisheng , Zhao Dongyuan
Published: May 2015

Uniform mesoporous single-crystal TiO
2
spheres with radial channels from driving orientation assembly can be used for energy storage.
Role of Extracellular Structures of Escherichia coli O157:H7 in Initial Attachment to Biotic and Abiotic Surfaces
Authors: Nagy Attila , Mowery Joseph , Bauchan Gary R. , Wang Lili , Nichols-Russell Lydia , Nou Xiangwu
Published: May 2015

Infection by human pathogens through the consumption of fresh, minimally processed produce and solid plant-derived foods is a major concern of the U.S. and global food industries and of public health services. Enterohemorrhagic
Escherichia coli
O157:H7 is a frequent and potent foodborne pathogen that causes severe disease in humans. Biofilms formed by
E. coli
O157:H7 facilitate cross-contamination by sheltering pathogens and protecting them from cleaning and sanitation operations. The objective of this research was to determine the role that several surface structures of
E. coli
O157:H7 play in adherence to biotic and abiotic surfaces. A set of isogenic deletion mutants lacking major surface structures was generated. The mutant strains were inoculated onto fresh spinach and glass surfaces, and their capability to adhere was assessed by adherence assays and fluorescence microscopy methods. Our results showed that filament-deficient mutants bound to the spinach leaves and glass surfaces less strongly than the wild-type strain did. We mimicked the switch to the external environment—during which bacteria leave the host organism and adapt to lower ambient temperatures of cultivation or food processing—by decreasing the temperature from 37°C to 25°C and 4°C. We concluded that flagella and some other cell surface proteins are important factors in the process of initial attachment and in the establishment of biofilms. A better understanding of the specific roles of these structures in early stages of biofilm formation can help to prevent cross-contaminations and foodborne disease outbreaks.
The Host Genotype and Environment Affect Strain Types of Bifidobacterium longum subsp. longum Inhabiting the Intestinal Tracts of Twins
Authors: Zhang Min , Hang Xiaomin , Tan Jing , Yang Hong
Published: May 2015

To investigate the influences of host genotype and environment on
Bifidobacterium longum
subsp.
longum
inhabiting human intestines at the strain level, six pairs of twins, divided into two groups (children and adults), were recruited. Each group consisted of two monozygotic (MZ) twin pairs and one dizygotic (DZ) twin pair. Child twins had been living together from birth, while adult twins had been living separately for 5 to 10 years. A total of 345
B. longum
subsp.
longum
isolates obtained from 60 fecal samples from these twins were analyzed by multilocus sequence typing (MLST), and 35 sequence types (STs) were finally acquired. Comparison of strains within and between the twin pairs showed that no strains with identical STs were observed between unrelated individuals or within adult DZ twin pairs. Eight STs were found to be monophyletic, existing within MZ twins and child DZ twins. The similarity of strain types within child cotwins was significantly higher than that within adult cotwins, which indicated that environment was one of the important determinants in
B. longum
subsp.
longum
strain types inhabiting human intestines. However, although these differences between MZ and DZ twins were observed, it is still difficult to reach an exact conclusion about the impact of host genotype. This is mainly because of the limited number of subjects tested in the present study and the lack of strain types tracing in the same twin pairs from birth until adulthood.
Giardia spp. Are Commonly Found in Mixed Assemblages in Surface Water, as Revealed by Molecular and Whole-Genome Characterization
Authors: Prystajecky Natalie , Tsui Clement K.-M. , Hsiao William W. L. , Uyaguari-Diaz Miguel I. , Ho Jordan , Tang Patrick , Isaac-Renton Judith
Published: May 2015

Giardiais the most common parasitic cause of gastrointestinal infections worldwide, with transmission through surface water playing an important role in various parts of the world.Giardia duodenalis(synonyms:G. intestinalisandG. lamblia), a multispecies complex, has two zoonotic subtypes, assemblages A and B. When British Columbia (BC), a western Canadian province, experienced several waterborne giardiasis outbreaks due to unfiltered surface drinking water in the late 1980s, collection of isolates from surface water, as well as from humans and beavers (Castor canadensis), throughout the province was carried out. To better understandGiardiain surface water, 71 isolates, including 29 from raw surface water samples, 29 from human giardiasis cases, and 13 from beavers in watersheds from this historical library were characterized by PCR. Study isolates also included isolates from waterborne giardiasis outbreaks. Both assemblages A and B were identified in surface water, human, and beavers samples, including a mixture of both assemblages A and B in waterborne outbreaks. PCR results were confirmed by whole-genome sequencing (WGS) for one waterborne outbreak and supported the clustering of human, water, and beaver isolates within both assemblages. We concluded that contamination of surface water byGiardiais complex, that the majority of our surface water isolates were assemblage B, and that both assemblages A and B may cause waterborne outbreaks. The higher-resolution data provided by WGS warrants further study to better understand the spread ofGiardia.
Phytobeneficial Properties of Bacteria Isolated from the Rhizosphere of Maize in Southwestern Nigerian Soils
Authors: Abiala M. A. , Odebode A. C. , Hsu S. F. , Blackwood C. B.
Published: May 2015

Biocontrol agents isolated outside Africa have performed inconsistently under field conditions in Africa. The development of indigenous phytobeneficial microbial strains that suit local environments may help enhance competitiveness with
in situ
microorganisms and effectiveness at suppressing local pathogen strains. We isolated bacteria from the rhizosphere of maize growing in southwestern Nigeria and assessed them for growth-promoting characteristics. The best isolates were characterized using 16S rRNA genes and were further evaluated in the greenhouse on maize seedlings. Four isolates (EBS8, IGBR11, EPR2, and ADS14) were outstanding in
in vitro
assays of antagonistic activity against a local strain of
Fusarium verticillioides
, phosphate solubilization efficiency, chitinase enzyme activity, and indole-3-acetic acid production. Inoculation of maize seeds with these isolates resulted in ≥95% maize seed germination and significantly enhanced radicle and plumule length. In the greenhouse, maize seedling height, stem girth, number of leaves, leaf area, shoot mass (dry matter), and nutrient contents were significantly enhanced. The bioprotectant and phytobeneficial effects were strongest and most consistent for isolate EBS8, which was identified as a
Bacillus
strain by 16S rRNA gene analysis. As a bacterial strain that exhibits multiple growth-promoting characteristics and is adapted to local conditions, EBS8 should be considered for the development of indigenous biological fertilizer treatments.
Semiquantitative Performance and Mechanism Evaluation of Carbon Nanomaterials as Cathode Coatings for Microbial Fouling Reduction
Authors: Zhang Qiaoying , Nghiem Joanne , Silverberg Gregory J. , Vecitis Chad D.
Published: May 2015

In this study, we examine bacterial attachment and survival on a titanium (Ti) cathode coated with various carbon nanomaterials (CNM): pristine carbon nanotubes (CNT), oxidized carbon nanotubes (O-CNT), oxidized-annealed carbon nanotubes (OA-CNT), carbon black (CB), and reduced graphene oxide (rGO). The carbon nanomaterials were dispersed in an isopropyl alcohol-Nafion solution and were then used to dip-coat a Ti substrate.
Pseudomonas fluorescens
was selected as the representative bacterium for environmental biofouling. Experiments in the absence of an electric potential indicate that increased nanoscale surface roughness and decreased hydrophobicity of the CNM coating decreased bacterial adhesion. The loss of bacterial viability on the noncharged CNM coatings ranged from 22% for CB to 67% for OA-CNT and was dependent on the CNM dimensions and surface chemistry. For electrochemical experiments, the total density and percentage of inactivation of the adherent bacteria were analyzed semiquantitatively as functions of electrode potential, current density, and hydrogen peroxide generation. Electrode potential and hydrogen peroxide generation were the dominant factors with regard to short-term (3-h) bacterial attachment and inactivation, respectively. Extended-time electrochemical experiments (12 h) indicated that in all cases, the density of total deposited bacteria increased almost linearly with time and that the rate of bacterial adhesion was decreased 8- to 10-fold when an electric potential was applied. In summary, this study provides a fundamental rationale for the selection of CNM as cathode coatings and electric potential to reduce microbial fouling.
Effects of Abiotic and Biotic Stresses on the Internalization and Dissemination of Human Norovirus Surrogates in Growing Romaine Lettuce
Authors: DiCaprio Erin , Purgianto Anastasia , Li Jianrong
Published: May 2015

Human norovirus (NoV) is the major causative agent of fresh-produce-related outbreaks of gastroenteritis; however, the ecology and persistence of human NoV in produce systems are poorly understood. In this study, the effects of abiotic and biotic stresses on the internalization and dissemination of two human NoV surrogates (murine norovirus 1 [MNV-1] and Tulane virus [TV]) in romaine lettuce were determined. To induce abiotic stress, romaine lettuce was grown under drought and flood conditions that mimic extreme weather events, followed by inoculation of soil with MNV-1 or TV. Independently, lettuce plants were infected with lettuce mosaic virus (LMV) to induce biotic stress, followed by inoculation with TV. Plants were grown for 14 days, and viral titers in harvested tissues were determined by plaque assays. It was found that drought stress significantly decreased the rates of both MNV-1 and TV internalization and dissemination. In contrast, neither flood stress nor biotic stress significantly impacted viral internalization or dissemination. Additionally, the rates of TV internalization and dissemination in soil-grown lettuce were significantly higher than those for MNV-1. Collectively, these results demonstrated that (i) human NoV surrogates can be internalized via roots and disseminated to shoots and leaves of romaine lettuce grown in soil, (ii) abiotic stress (drought) but not biotic stress (LMV infection) affects the rates of viral internalization and dissemination, and (iii) the type of virus affects the efficiency of internalization and dissemination. This study also highlights the need to develop effective measures to eliminate internalized viruses in fresh produce.
Energy Conservation Model Based on Genomic and Experimental Analyses of a Carbon Monoxide-Utilizing, Butyrate-Forming Acetogen, Eubacterium limosum KIST612
Authors: Jeong Jiyeong , Bertsch Johannes , Hess Verena , Choi Sunju , Choi In-Geol , Chang In Seop , Müller Volker
Published: May 2015

Eubacterium limosum
KIST612 is one of the few acetogens that can produce butyrate from carbon monoxide. We have used a genome-guided analysis to delineate the path of butyrate formation, the enzymes involved, and the potential coupling to ATP synthesis. Oxidation of CO is catalyzed by the acetyl-coenzyme A (CoA) synthase/CO dehydrogenase and coupled to the reduction of ferredoxin. Oxidation of reduced ferredoxin is catalyzed by the Rnf complex and Na
+
dependent. Consistent with the finding of a Na
+
-dependent Rnf complex is the presence of a conserved Na
+
-binding motif in the
c
subunit of the ATP synthase. Butyrate formation is from acetyl-CoA via acetoacetyl-CoA, hydroxybutyryl-CoA, crotonyl-CoA, and butyryl-CoA and is consistent with the finding of a gene cluster that encodes the enzymes for this pathway. The activity of the butyryl-CoA dehydrogenase was demonstrated. Reduction of crotonyl-CoA to butyryl-CoA with NADH as the reductant was coupled to reduction of ferredoxin. We postulate that the butyryl-CoA dehydrogenase uses flavin-based electron bifurcation to reduce ferredoxin, which is consistent with the finding of
etfA
and
etfB
genes next to it. The overall ATP yield was calculated and is significantly higher than the one obtained with H
2
+ CO
2
. The energetic benefit may be one reason that butyrate is formed only from CO but not from H
2
+ CO
2
.
Thermal Inactivation Kinetics of Human Norovirus Surrogates and Hepatitis A Virus in Turkey Deli Meat
Authors: Bozkurt Hayriye , D'Souza Doris H. , Davidson P. Michael
Published: May 2015

Human noroviruses (HNoV) and hepatitis A virus (HAV) have been implicated in outbreaks linked to the consumption of presliced ready-to-eat deli meats. The objectives of this research were to determine the thermal inactivation kinetics of HNoV surrogates (murine norovirus 1 [MNV-1] and feline calicivirus strain F9 [FCV-F9]) and HAV in turkey deli meat, compare first-order and Weibull models to describe the data, and calculate Arrhenius activation energy values for each model. The
D
(decimal reduction time) values in the temperature range of 50 to 72°C calculated from the first-order model were 0.1 ± 0.0 to 9.9 ± 3.9 min for FCV-F9, 0.2 ± 0.0 to 21.0 ± 0.8 min for MNV-1, and 1.0 ± 0.1 to 42.0 ± 5.6 min for HAV. Using the Weibull model, the
t
D = 1
(time to destroy 1 log) values for FCV-F9, MNV-1, and HAV at the same temperatures ranged from 0.1 ± 0.0 to 11.9 ± 5.1 min, from 0.3 ± 0.1 to 17.8 ± 1.8 min, and from 0.6 ± 0.3 to 25.9 ± 3.7 min, respectively. The
z
(thermal resistance) values for FCV-F9, MNV-1, and HAV were 11.3 ± 2.1°C, 11.0 ± 1.6°C, and 13.4 ± 2.6°C, respectively, using the Weibull model. The
z
values using the first-order model were 11.9 ± 1.0°C, 10.9 ± 1.3°C, and 12.8 ± 1.7°C for FCV-F9, MNV-1, and HAV, respectively. For the Weibull model, estimated activation energies for FCV-F9, MNV-1, and HAV were 214 ± 28, 242 ± 36, and 154 ± 19 kJ/mole, respectively, while the calculated activation energies for the first-order model were 181 ± 16, 196 ± 5, and 167 ± 9 kJ/mole, respectively. Precise information on the thermal inactivation of HNoV surrogates and HAV in turkey deli meat was generated. This provided calculations of parameters for more-reliable thermal processes to inactivate viruses in contaminated presliced ready-to-eat deli meats and thus to reduce the risk of foodborne illness outbreaks.
Use of Hybridization Chain Reaction-Fluorescent
In Situ
Hybridization To Track Gene Expression by Both Partners during Initiation of Symbiosis
Authors: Nikolakakis K. , Lehnert E. , McFall-Ngai M. J. , Ruby E. G.
Published: May 2015

The establishment of a productive symbiosis between
Euprymna scolopes
, the Hawaiian bobtail squid, and its luminous bacterial symbiont,
Vibrio fischeri
, is mediated by transcriptional changes in both partners. A key challenge to unraveling the steps required to successfully initiate this and many other symbiotic associations is characterization of the timing and location of these changes. We report on the adaptation of hybridization chain reaction-fluorescent
in situ
hybridization (HCR-FISH) to simultaneously probe the spatiotemporal regulation of targeted genes in both
E. scolopes
and
V. fischeri
. This method revealed localized, transcriptionally coregulated epithelial cells within the light organ that responded directly to the presence of bacterial cells while, at the same time, provided a sensitive means to directly show regulated gene expression within the symbiont population. Thus, HCR-FISH provides a new approach for characterizing habitat transition in bacteria and for discovering host tissue responses to colonization.
Enterocin F4-9, a Novel
O
-Linked Glycosylated Bacteriocin
Authors: Maky Mohamed Abdelfattah , Ishibashi Naoki , Zendo Takeshi , Perez Rodney Honrada , Doud Jehan Ragab , Karmi Mohamed , Sonomoto Kenji
Published: May 2015

Enterococcus faecalis
F4-9 isolated from Egyptian salted-fermented fish produces a novel bacteriocin, termed enterocin F4-9. Enterocin F4-9 was purified from the culture supernatant by three steps, and its molecular mass was determined to be 5,516.6 Da by mass spectrometry. Amino acid and DNA sequencing showed that the propeptide consists of 67 amino acid residues, with a leader peptide containing a double glycine cleavage site to produce a 47-amino-acid mature peptide. Enterocin F4-9 is modified by two molecules of
N
-acetylglucosamine β-
O
-linked to Ser37 and Thr46. The
O
-linked
N
-acetylglucosamine moieties are essential for the antimicrobial activity of enterocin F4-9. Further analysis of the enterocin F4-9 gene cluster identified
enfC
, which has high sequence similarity to a glycosyltransferase. The antimicrobial activity of enterocin F4-9 covered a limited range of bacteria, including, interestingly, a Gram-negative strain,
Escherichia coli
JM109. Enterocin F4-9 is sensitive to protease, active at a wide pH range, and moderately resistant to heat.
Intracellular Accumulation of Glycine in Polyphosphate-Accumulating Organisms in Activated Sludge, a Novel Storage Mechanism under Dynamic Anaerobic-Aerobic Conditions
Authors: Nguyen Hien Thi Thu , Kristiansen Rikke , Vestergaard Mette , Wimmer Reinhard , Nielsen Per Halkjær
Published: May 2015

Dynamic anaerobic-aerobic feast-famine conditions are applied to wastewater treatment plants to select polyphosphate-accumulating organisms to carry out enhanced biological phosphorus removal. Acetate is a well-known substrate to stimulate this process, and here we show that different amino acids also are suitable substrates, with glycine as the most promising.
13
C-labeled glycine and nuclear magnetic resonance (NMR) were applied to investigate uptake and potential storage products when activated sludge was fed with glycine under anaerobic conditions. Glycine was consumed by the biomass, and the majority was stored intracellularly as free glycine and fermentation products. Subsequently, in the aerobic phase without addition of external substrate, the stored glycine was consumed. The uptake of glycine and oxidation of intracellular metabolites took place along with a release and uptake of orthophosphate, respectively. Fluorescence
in situ
hybridization combined with microautoradiography using
3
H-labeled glycine revealed uncultured actinobacterial
Tetrasphaera
as a dominant glycine consumer. Experiments with
Tetrasphaera elongata
as representative of uncultured
Tetrasphaera
showed that under anaerobic conditions it was able to take up labeled glycine and accumulate this and other labeled metabolites to an intracellular concentration of approximately 4 mM. All components were consumed under subsequent aerobic conditions. Intracellular accumulation of amino acids seems to be a novel storage strategy for polyphosphate-accumulating bacteria under dynamic anaerobic-aerobic feast-famine conditions.
Biochemical and Kinetic Characterization of the Eukaryotic Phosphotransacetylase Class IIa Enzyme from Phytophthora ramorum
Authors: Taylor Tonya , Ingram-Smith Cheryl , Smith Kerry S.
Published: May 2015

Phosphotransacetylase (Pta), a key enzyme in bacterial metabolism, catalyzes the reversible transfer of an acetyl group from acetyl phosphate to coenzyme A (CoA) to produce acetyl-CoA and Pi. Two classes of Pta have been identified based on the absence (PtaI) or presence (PtaII) of an N-terminal regulatory domain. PtaIhas been fairly well studied in bacteria and one genus of archaea; however, only theEscherichia coliandSalmonella entericaPtaIIenzymes have been biochemically characterized, and they are allosterically regulated. Here, we describe the first biochemical and kinetic characterization of a eukaryotic Pta from the oomycetePhytophthora ramorum. The two Ptas fromP. ramorum, designated PrPtaII1 and PrPtaII2, both belong to class II. PrPtaII1 displayed positive cooperativity for both acetyl phosphate and CoA and is allosterically regulated. We compared the effects of different metabolites on PrPtaII1 and theS. entericaPtaIIand found that, although the N-terminal regulatory domains share only 19% identity, both enzymes are inhibited by ATP, NADP, NADH, phosphoenolpyruvate (PEP), and pyruvate in the acetyl-CoA/Pi-forming direction but are differentially regulated by AMP. Phylogenetic analysis of bacterial, archaeal, and eukaryotic sequences identified four subtypes of PtaIIbased on the presence or absence of the P-loop and DRTGG subdomains within the N-terminal regulatory domain. Although theE. coli,S. enterica, andP. ramorumenzymes all belong to the IIa subclass, our kinetic analysis has indicated that enzymes within a subclass can still display differences in their allosteric regulation.
Recent Lithuanian peri-urban ombrotrophic bog records: indices derived from the contents of lead, zinc, copper and nickel
Authors: Zinkutė R. , Baužienė I. , Dilys K. , Mažeika J. , Taminskas J. , Taraškevičius R.
Published: May 2015

Two Lithuanian
c
. 50-cm long peat cores from ombrotrophic bogs were analysed, namely, Rėkyva near Šiauliai and Žudiškės near Vilnius. Ash content, bulk density, chemical element concentrations determined by EDXRF and
210
Pb dating by gamma spectrometric methods were used. Geochemical data of deep Rėkyva peatland mine layers, dated by
14
C to the BC/AD boundary, enable the estimation of reference values for the calculation of increase coefficients (IC) in the young (formed after 1900) layers of cores, where IC values exceed 26.3 for Pb, 2.9 for Zn, 2.4 for Cu and 2.3 for Ni. The young layers compared to the older ones are characterized by an increase of ash and most elemental contents and the disappearance of a positive correlation between ash and Pb, Zn, Cu, Ni contents. Higher median values of IC and the anthropogenic accumulation rate (AR) in young Rėkyva are predetermined mainly by soil dust, higher median enrichment factors (EF) of Zn, Cu, Ni and median percentages of their anthropogenic component by higher industrialization of Vilnius and the leeward location of Žudiškės. The timing of maximum or next high EF and anthropogenic AR (mg m
–2
yr
–1
) of Pb (10.1), Zn (7.0), Cu (1.1), Ni (1.2) in Žudiškės (1970-1974) corresponds to general results over Europe.