bluuebunny/crossref_metadata_2025 huggingface dataset:
Translating nodes of power through reflexive ethnographic writing
Authors: Mahadevan Jasmin
Published: April 2012

Purpose

The purpose of this paper is to show the benefit of conceptualizing reflexive ethnographic writing as translation processes across circuits of power that involve researcher, field and audience. For this purpose, a model of translating nodes of power in the ethnographic triangle is developed.

Design/methodology/approach

The author reflects upon organizational ethnography theoretically.

Findings

Ethnographic meaning emerges between researcher, field and audience (the ethnographic triangle). The author conceptualizes their relations as relations of power and draws from Clegg's circuits of power to map these relations. The author argues that ethnographers need to conceptualize power in the ethnographic triangle as three interrelated circuits of power, namely episodic power relations, rules of practice and structures of domination. This approach advances previous work on reflexivity in three aspects. First, it goes beyond individual researcher‐field interaction and integrates agency, practice and structure from a power‐perspective; second, it incorporates exotextual influences; and third, it is also a viable reflexive path if researcher and field cannot establish cooperation.

Research limitations/implications

This paper provides a processual model to interrogate reflexive ethnographic writing. However, this model cannot solve issues of temporal reflexivity.

Originality/value

Reflexive ethnographic practice is viewed as translating nodes of power across circuits of power. This view implies that innocent reflexivity is not possible. Still, it might enable the researcher by providing an alternative reading of ethnographic practice.
MHC diversity, malaria and lifetime reproductive success in collared flycatchers
Authors: RADWAN JACEK , ZAGALSKA‐NEUBAUER MAGDALENA , CICHOŃ MARIUSZ , SENDECKA JOANNA , KULMA KATARZYNA , GUSTAFSSON LARS , BABIK WIESŁAW
Published: April 2012

Major histocompatibility complex (MHC) genes encode proteins involved in the recognition of parasite‐derived antigens. Their extreme polymorphism is presumed to be driven by co‐evolution with parasites. Host–parasite co‐evolution was also hypothesized to optimize within‐individual MHC diversity at the intermediate level. Here, we use unique data on lifetime reproductive success (LRS) of female collared flycatchers to test whether LRS is associated with within‐individual MHC class II diversity. We also examined the association between MHC and infection with avian malaria. Using 454 sequencing, we found that individual flycatchers carry between 3 and 23 functional MHC class II B alleles. Predictions of the optimality hypothesis were not confirmed by our data as the prevalence of blood parasites decreased with functional MHC diversity. Furthermore, we did not find evidence for an association between MHC diversity and LRS.
Esophageal impedance baselines in infants before and after placebo and proton pump inhibitor therapy
Authors: Loots C. M. , Wijnakker R. , van Wijk M. P. , Davidson G. , Benninga M. A. , Omari T. I.
Published: April 2012

Background  Esophageal impedance monitoring records changes in conductivity. During esophageal rest, impedance baseline values may represent mucosal integrity. The aim of this study was to assess the influence of acid suppression on impedance baselines in a placebo‐controlled setting.

Methods  Impedance recordings from 40 infants (0–6 months) enrolled in randomized placebo‐controlled trials of proton pump inhibitor (PPI) were retrospectively analyzed. Infants underwent 24 h pH‐impedance monitoring prior to and after 2 weeks of double blind therapy with placebo or a PPI. Typical clinical signs of gastro‐esophageal reflux (GER) were recorded and I‐GERQ‐R questionnaire was completed.

Key Results  Median (IQR) impedance baseline increased on PPI treatment (from 1217 (826–1514) to 1903 (1560–2194) Ω, P < 0.001) but not with placebo (from 1445 (1033–1791) to 1650 (1292–1983) Ω, P = 0.13). Baselines before treatment inversely correlate with the number of GER, acid GER, weakly acid GER, acid exposure, and symptoms. The change in baseline on treatment inversely correlates with acid exposure and acid GER. Patients with initial low baselines have no improved symptomatic response to treatment.

Conclusions & Inferences  Impedance baselines are influenced by GER and increase significantly more with PPI therapy than with placebo. Clinical impact of this observation remains undefined as targeting therapy at infants with low baselines does not improve symptomatic response to treatment.
Potential mechanisms for the association between fall birth and food allergy
Authors: Keet C. A. , Matsui E. C. , Savage J. H. , Neuman‐Sunshine D. L. , Skripak J. , Peng R. D. , Wood R. A.
Published: April 2012

Background

Season of birth has been reported as a risk factor for food allergy, but the mechanisms by which it acts are unknown.

Methods

Two populations were studied: 5862 children from the National Health and Nutrition Examination Survey (NHANES) III and 1514 well‐characterized food allergic children from the Johns Hopkins Pediatric Allergy Clinic (JHPAC). Food allergy was defined as self‐report of an acute reaction to a food (NHANES), or as milk, egg, and peanut allergy. Logistic regression compared fall or nonfall birth between (i) food allergic and nonallergic subjects in NHANES, adjusted for ethnicity, age, income, and sex, and (ii) JHPAC subjects and the general Maryland population. For NHANES, stratification by ethnicity and for JHPAC, eczema were examined.

Results

Fall birth was more common among food allergic subjects in both NHANES (OR, 1.91; 95% CI, 1.31–2.77) and JHPAC/Maryland (OR, 1.31; 95% CI, 1.18–1.47). Ethnicity interacted with season (OR, 2.34; 95% CI, 1.43–3.82 for Caucasians; OR, 1.19; 95% CI, 0.77–1.86 for non‐Caucasians; P = 0.04 for interaction), as did eczema (OR, 1.47; 95% CI, 1.29–1.67 with eczema; OR, 1.00; 95% CI, 0.80–1.23 without eczema; P = 0.002 for interaction).

Conclusions

Fall birth is associated with increased risk of food allergy, and this risk is greatest among those most likely to have seasonal variation in vitamin D during infancy (Caucasians) and those at risk for skin barrier dysfunction (subjects with a history of eczema), suggesting that vitamin D and the skin barrier may be implicated in seasonal associations with food allergy.
Initial operative experience of single‐port retroperitoneal laparoscopic nephrectomy
Authors: Okegawa Takatsugu , Itaya Naoshi , Hara Hidehiko , Nutahara Kikuo , Higashihara Eiji
Published: April 2012

This paper reports our early experience with single‐port laparoscopic nephrectomy via the retroperitoneal approach. Since April 2010, 23 patients have undergone single‐port laparoscopic surgery for simple nephrectomy (n = 11 patients) and radical nephrectomy (n = 12) by an experienced laparoscopic surgeon. The mean operative time was 265.2 min and the mean estimated blood loss was 96.7 mL. The procedure was completed in all patients without conversion to standard laparoscopy or open surgery. No intraoperative or acute postoperative complications occurred. When the single‐port retroperitoneal laparoscopic nephrectomy group was retrospectively compared with the group that had undergone standard retroperitoneal laparoscopic nephrectomy, no significant difference was noted with respect to age, body mass index, operation time, time to eat, catheter removal or length of hospitalization (P > 0.05). A significant difference in favor of the single‐port retroperitoneal laparoscopic nephrectomy group was noted with respect to the estimated blood loss (P = 0.027) and the visual analog pain scale score at discharge (P = 0.016). Although our findings show that retroperitoneal single‐port laparoscopic nephrectomy is feasible with advanced techniques and optimal instrumentation, further study is required to determine the future extent of its clinical application.
Preservation of the smooth muscular internal (vesical) sphincter and of the proximal urethra during retropubic radical prostatectomy: Description of the technique
Authors: Brunocilla Eugenio , Pultrone Cristian , Pernetti Remigio , Schiavina Riccardo , Martorana Giuseppe
Published: April 2012

We describe our technique for preservation of the smooth muscular internal (vesical) sphincter and proximal urethra during radical retropubic prostatectomy. The first steps of the prostatectomy reflect the standard retropubic prostatectomy; whereas for the final phases, the procedure continues in an anterograde manner with incision of the fibers of the detrusor muscle at the insertion of the ventral surface of the base of the prostate. At this level, the inner circular muscle of the bladder neck forms a sphincteric ring of smooth muscle that covers the longitudinally‐oriented smooth muscle component of the urethra that extends distally to the verumontanum; these two proximal structures represent the internal sphincter that envelops and locks the proximal urethra. A blunt dissection is continued until the ring‐shaped vesical sphincter is separated from the prostate and the longitudinally‐oriented smooth muscle component of the urethral musculature is identified. The base of the prostate is then gently separated from the urethra and from the bladder until the maximal length of the urethral musculature is isolated and preserved. Finally, a urethra‐urethral anastomosis is carried out and the ventral stitches are placed through the circular fibres of the bladder neck. In all cases we carry out circumferential biopsies of the proximal urethra and of the base of the prostate. The described technique is a feasible and safe method for preservation of the internal urethral sphincter. Despite the enthusiasm regarding our positive functional results, further studies with larger series are required to confirm these findings.
Care of the Self, Care of the Earth: A New Conversation for Rio+20?
Authors: Doran Peter
Published: April 2012

What if capitalism, understood as an economic, social and cultural complex, was on the agenda of a world summit on sustainable development? How has the culture of capitalism – its psychic investment in colonizing our attention – compromised our ability to respond meaningfully to the challenges of sustainable development? Those are two of the questions behind this exploration of the constraints that appear to limit the scope of economic debate at conferences such as Rio+20 in Rio de Janeiro in 2012. There is an emerging consensus that consumerist excess and the media complex of consumerism are bad for us, environmentally, socially and psychologically. This article suggests that we underestimate the way in which our immersion in the ‘social logic’ of capitalist consumption constrains our attempts to understand and respond to the ecological crises at both a personal and political level – and that both dimensions of our response are bound together. In an acknowledgement of a certain closure around such themes within Western thought, the article looks to a point of exteriority in Peter Hershock's work, drawing on China's Chan Buddhist philosophy, for intimations of a worldview that challenges the West's over‐commitment to forms of ‘control’ in favour of a cultivation of mindful and careful awareness – and an offering of unconditional attention.
Affirmative Action and the Occupational Advancement of Minorities and Women During 1973–2003
Authors: KURTULUS FIDAN ANA
Published: April 2012

The share of minorities and women comprising high‐paying skilled occupations such as management, professional, and technical occupations has been increasing since the 1960s, while the proportion of white men in such occupations has been declining. What has been the contribution of affirmative action to the occupational advancement of minorities and women from low‐wage unskilled occupations into high‐wage skilled ones in U.S. firms? I examine this by comparing the occupational position of minorities and women at firms holding federal contracts, and thereby mandated to implement affirmative action, and noncontracting firms, over the course of 31 years during 1973–2003. I use a new longitudinal dataset of over 100,000 large private‐sector firms across all industries and regions uniquely suited for the exploration of this question obtained from the U.S. Equal Employment Opportunity Commission. My key findings show that the share of minorities and women in high‐paying skilled occupations grew more at federal contractors subject to affirmative action obligation than at noncontracting firms during the three decades under study, but these advances took place primarily during the pre‐ and early Reagan years and during the decade following the Glass Ceiling Act of 1991.
Psychopathology in children before and after surgery for extratemporal lobe epilepsy
Authors: COLONNELLI M CHIARA , CROSS J HELEN , DAVIES SHARON , D’ARGENZIO LUIGI , SCOTT ROD C , PICKLES ANDREW , HANNAN SIOBHAN , HARKNESS WILLIAM , HEYMAN ISOBEL
Published: April 2012

Aim  To establish the rates and types of psychiatric disorder in children before and after surgery for extratemporal epilepsy. Relationships between psychiatric morbidity and demographic/clinical variables were examined.

Method  A retrospective case note review of 71 children undergoing extratemporal focal resection for drug resistant epilepsy in a specialist epilepsy surgery programme between 1997 and 2008. Psychiatric diagnoses were derived from pre‐ and postoperative assessments according to DSM‐IV criteria.

Results  Seventy‐one children (38 males, 33 females) were eligible for this study. Mean age (SD) at surgery was 9 (5) years. Frontal resections were performed in 73% of the children, parietal in 17%, and occipital in 10%. Mental health problems were present in 37 of 71 (52%) children pre‐ and/or postoperatively. A similar proportion of children had psychiatric diagnoses pre‐ and postoperatively: 31 of 71 (44%) and 32 of 71 (45%) respectively.

Interpretation  Psychopathology is common in children with extratemporal epilepsy. In this sample, the impact of surgery on psychiatric symptoms was not predictable: some children were unchanged, others improved, and others acquired new psychiatric diagnoses postoperatively. Given the high rates of psychiatric disorder in this group of patients, detection and treatment of mental health needs may be important.
Risk and causes of death in children with a seizure disorder
Authors: NESBITT VICTORIA , KIRKPATRICK MARTIN , PEARSON GALE , COLVER ALLAN , FORSYTH ROB
Published: April 2012

Aim  To describe the frequency and causes of death in children with epilepsy, ascertain the contribution of seizure disorder to cause of death, and compare with rates of sudden unexplained death in children without epilepsy.

Method  This study was a retrospective review of clinical and death certificate records. It examined two UK population‐based samples of deaths in children with epilepsy from 1 month to 18 years, together comprising the largest reported series of deaths in children with epilepsy (n=265).

Results  In approximately two‐thirds, the death was not due to the seizure disorder. Rates of unexplained death were similar in the two samples at 7.3% and 9.7%: all were in children with symptomatic or presumed symptomatic epilepsy. There were no unexplained deaths in the children with idiopathic epilepsy. Four per cent of the deaths were of children experiencing acute symptomatic seizures as part of their final illness. The risk of unexpected, unexplained death in children with idiopathic epilepsy is not more than 65 per 100 000 child‐years.

Interpretation  Epilepsy is associated with an increased risk of death in childhood but this risk is almost entirely confined to those with an associated neurodevelopmental disorder. The risk of unexpected, unexplained death in children with idiopathic epilepsy is extremely small.
The use of thallium diethyldithiocarbamate for mapping CNS potassium metabolism and neuronal activity: Tl+‐redistribution, Tl+‐kinetics and Tl+‐equilibrium distribution
Authors: Wanger Tim , Scheich Henning , Ohl Frank W. , Goldschmidt Jürgen
Published: April 2012

J. Neurochem. (2012) 122, 106–114.

The potassium (K+) analogue thallium (Tl+) can be used as a tracer for mapping neuronal activity. However, because of the poor blood–brain barrier (BBB) K+‐permeability, only minute amounts of Tl+ enter the brain after systemic injection of Tl+‐salts like thallium acetate (TlAc). We have recently shown that it is possible to overcome this limitation by injecting animals with the lipophilic chelate complex thallium diethyldithiocarbamate (TlDDC), that crosses the BBB and releases Tl+ prior to neuronal or glial uptake. TlDDC can thus be used for mapping CNS K+ metabolism and neuronal activity. Here, we analyze Tl+‐kinetics in the rodent brain both experimentally and using simple mathematical models. We systemically injected animals either with TlAc or with TlDDC. Using an autometallographic method we mapped the brain Tl+‐distribution at various time points after injection. We show that the patterns and kinetics of Tl+‐redistribution in the brain are essentially the same irrespective of whether animals have been injected with TlAc or TlDDC. Data from modeling and experiments indicate that transmembrane Tl+‐fluxes in cells within the CNS in vivo equilibrate at similar rates as K+‐fluxes in vitro. This equilibration is much faster than and largely independent of the equilibration of Tl+‐fluxes across the BBB. The study provides further proof‐of‐concept for the use of TlDDC for mapping neuronal activity and CNS K+‐metabolism. A theoretical guideline is given for the use of K+‐analogues for imaging neuronal activity with general implications for the use of metal ions in neuroimaging.
Shoulder sensorimotor control assessment by force platform: feasibility and reliability
Authors: Edouard Pascal , Gasq David , Calmels Paul , Ducrot Sarah , Degache Francis
Published: April 2012

Given the important role of the shoulder sensorimotor system in shoulder stability, its assessment appears of interest. Force platform monitoring of centre of pressure (CoP) in upper‐limb weight‐bearing positions is of interest as it allows integration of all aspects of shoulder sensorimotor control. This study aimed to determine the feasibility and reliability of shoulder sensorimotor control assessment by force platform. Forty‐five healthy subjects performed two sessions of CoP measurement using Win‐Posturo® Medicapteurs force platform in an upper‐limb weight‐bearing position with the lower limbs resting on a table to either the anterior superior iliac spines (P1) or upper patellar poles (P2). Four different conditions were tested in each position in random order: eyes open or eyes closed with trunk supported by both hands and eyes open with trunk supported on the dominant or non‐dominant side. P1 reliability values were globally moderate to high for CoP length, CoP velocity and CoP standard deviation (SD), standard error of measurement ranged from 6·0% to 26·5%, except for CoP area. P2 reliability values were globally low and not clinically acceptable. Our results suggest that shoulder sensorimotor control assessment by force platform is feasible and has good reliability in upper‐limb weight‐bearing positions when the lower limbs are resting on a table to the anterior superior iliac spines. CoP length, CoP velocity and CoP SD velocity appear to be the most reliable variables.
Potential for pharmacological manipulation of human embryonic stem cells
Authors: Atkinson Stuart P , Lako Majlinda , Armstrong Lyle
Published: April 2012

The therapeutic potential of human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) is vast, allowing disease modelling, drug discovery and testing and perhaps most importantly regenerative therapies. However, problems abound; techniques for cultivating self‐renewing hESCs tend to give a heterogeneous population of self‐renewing and partially differentiated cells and general include animal‐derived products that can be cost‐prohibitive for large‐scale production, and effective lineage‐specific differentiation protocols also still remain relatively undefined and are inefficient at producing large amounts of cells for therapeutic use. Furthermore, the mechanisms and signalling pathways that mediate pluripotency and differentiation are still to be fully appreciated. However, over the recent years, the development/discovery of a range of effective small molecule inhibitors/activators has had a huge impact in hESC biology. Large‐scale screening techniques, coupled with greater knowledge of the pathways involved, have generated pharmacological agents that can boost hESC pluripotency/self‐renewal and survival and has greatly increased the efficiency of various differentiation protocols, while also aiding the delineation of several important signalling pathways. Within this review, we hope to describe the current uses of small molecule inhibitors/activators in hESC biology and their potential uses in the future.

LINKED ARTICLES This article is part of a themed section on Regenerative Medicine and Pharmacology: A Look to the Future. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2013.169.issue‐2
CHLOROPLAST GENETIC TOOL FOR THE GREEN MICROALGAE HAEMATOCOCCUS PLUVIALIS (CHLOROPHYCEAE, VOLVOCALES)1
Authors: Gutiérrez Carla L. , Gimpel Javier , Escobar Carolina , Marshall Sergio H. , Henríquez Vitalia
Published: April 2012

At present, there is strong commercial demand for recombinant proteins, such as antigens, antibodies, biopharmaceuticals, and industrial enzymes, which cannot be fulfilled by existing procedures. Thus, an intensive search for alternative models that may provide efficiency, safety, and quality control is being undertaken by a number of laboratories around the world. The chloroplast of the eukaryotic microalgae Haematococcus pluvialis Flotow has arisen as a candidate for a novel expression platform for recombinant protein production. However, there are important drawbacks that need to be resolved before it can become such a system. The most significant of these are chloroplast genome characterizations, and the development of chloroplast transformation vectors based upon specific endogenous promoters and on homologous targeting regions. In this study, we report the identification and characterization of endogenous chloroplast sequences for use as genetic tools for the construction of H. pluvialis specific expression vectors to efficiently transform the chloroplast of this microalga via microprojectile bombardment. As a consequence, H. pluvialis shows promise as a platform for expressing recombinant proteins for biotechnological applications, for instance, the development of oral vaccines for aquaculture.
Peek‐a‐What? Infants’ Response to the Still‐Face Task After Normal and Interrupted Peek‐a‐Boo
Authors: Bigelow Ann E. , Best Caitlin
Published: April 2012

Infants’ sensitivity to the vitality or tension envelope within dyadic social exchanges was investigated by examining their responses following normal and interrupted games of peek‐a‐boo embedded in a Still‐Face Task. Infants 5–6 months old engaged in two modified Still‐Face Tasks with their mothers. In one task, the initial interaction ended with a sequence of normal peek‐a‐boos that included tension build‐up, peak, and release. In the other task, the initial interaction was followed by a sequence of peek‐a‐boos that ended with an interrupted peek‐a‐boo in which the build‐up was followed directly by the still face. Infants showed the still‐face effect with their attention and smiling when the still face followed the normal peek‐a‐boo sequence, but only with smiling when the still face followed the sequence with the interrupted peek‐a‐boo. Infants’ social bidding to their mothers in the still‐face phase was greater following the interrupted peek‐a‐boo sequence. When social exchanges are interrupted before the closure of the vitality envelope, infants respond with more attention vigilance and social bidding, demonstrating their awareness of the structure of social exchanges.
Relationships between higher‐level functional capacity and dental health behaviors in community‐dwelling older adults
Authors: Moriya Shingo , Tei Kanchu , Yamazaki Yutaka , Hata Hironobu , Kitagawa Yoshimasa , Inoue Nobuo , Miura Hiroko
Published: April 2012

doi: 10.1111/j.1741‐2358.2012.00654.x

Relationships between higher‐level functional capacity and dental health behaviors in community‐dwelling older adults

Objective:  The aim of the present study was to elucidate relationships between higher‐level functional capacity and dental health behaviours in community‐dwelling older adults.

Background:  In ageing society, it is necessary to promote oral health in the elderly, because good oral health is a significant contributing factor to good general health. Higher‐level functional capacity has been considered a crucial factor for successful independent living in the elderly. We hypothesised that functional capacity is a significant indicator of dental health behaviours.

Methods:  Three hundred and thirty‐eight adults aged 65 years or older were enrolled in this study. Higher‐level functional capacity was evaluated using the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG‐index). Univariate and multivariate models were constructed with dental health behaviours, such as regular visits to a dentist, brushing frequency and use of extra cleaning devices, as the dependent variable, and the total TMIG‐index score and its subcategory scores as the principal independent variable.

Results:  Univariate logistic regression analysis demonstrated a significant correlation between low TMIG‐index and ‘intellectual activity’ subcategory scores to lack of regular visits to a dentist and not using extra cleaning devices. Using a multivariate model, significant relationships remained after adjusting for a number of variables including demographics, medical status, lifestyle and number of remaining teeth.

Conclusion:  Intellectual activity of higher‐level functional capacity may be an accurate indicator of dental health behaviours in community‐dwelling older adults. Intellectual activity should be taken into consideration to effectively promote oral health behaviours and oral hygiene in elderly persons living independently.
The clinical presentation of a mid‐tail melanocytoma with sudden malignant transformation in a bay Irish Draught gelding
Authors: Poore L. A. , Rest J. R. , Knottenbelt D. C.
Published: April 2012

Equine melanocytic tumours may be either a benign or malignant skin disease. They commonly involve the skin of grey horses. There are no reports of mid‐tail melanocytoma with sudden malignant transformation. Partial tail amputation was used to resect a melanocytic tumour mass from the mid‐tail of a 16‐year‐old bay Irish Draught (ID) horse. There was no evidence of significant re‐growth or complications at a 6‐month post operative examination.
Computation of variance in compartment model parameter estimates from dynamic PET data
Authors: Kamasak Mustafa E.
Published: April 2012

Purpose:

This paper investigates the validity of the analytical framework for variance (“analytical variance”) in kinetic parameter and macroparameter estimations. Analytical variance is compared against the variance obtained from Monte Carlo simulations (“MC variance”) for two different compartment models at different noise levels.

Methods:

Kinetic parameters for one‐tissue (1T) and two‐tissue (2T) compartment models are used to generate time–activity curves (TAC). Gaussian noise is added to the noiseless TAC to generate noise realizations for each noise level. The kinetic parameters are then estimated by minimizing the weighted squared error between the noisy TAC and the model output. Standard deviation is computed statistically from the estimated parameters and computed analytically using the framework at each noise level. The ratio of standard deviation to true parameter value obtained from Monte Carlo simulations and analytical computations is compared.

Results:

Difference between the analytical and MC variance increases with the level of noise and complexity of the compartment model. The standard deviation of the analytical variance also increases with the noise‐level and model complexity. The difference between the analytical and MC variance is less than 3% for 1T compartment model and less than 10% for 2T compartment model at all noise levels. In addition, the standard deviation in the analytical variance is less than 15% for 1T and 2T compartment models at all noise levels.

Conclusions:

These results indicate that the proposed framework for the variance in the kinetic parameter estimations can be used for 1T and 2T compartment models even in the existence of high noise.
Comment on “Detection of Emerging Sunspot Regions in the Solar Interior”
Authors: Braun Douglas C.
Published: April 2012

Ilonidis
et al
. (Reports, 19 August 2011, p. 993) report acoustic travel-time decreases associated with emerging sunspot regions before their appearance on the solar surface. An independent analysis using helioseismic holography does not confirm these travel-time anomalies for the four regions illustrated by Ilonidis
et al
. This negative finding is consistent with expectations based on current emerging flux models.
Saving Money Essential for Next Census, Says Departing Director
Authors: Mervis Jeffrey
Published: April 2012

Sociologist Robert Groves announced last week that he would be leaving the Census Bureau in August.
Science
interviewed him on 13 April.
Nanoparticles Offer ‘Open Sesame’ Keys to New Drugs and Vaccines
Authors: Service Robert F.
Published: April 2012

Research presented at the ACS meeting suggests that packing RNA strands together to form nano-sized particles could help get them into target cells and that another nanoparticle may lead to novel kinds of vaccines.
High Diversity and Novel Species of Pseudomonas aeruginosa Bacteriophages
Authors: Sepúlveda-Robles Omar , Kameyama Luis , Guarneros Gabriel
Published: April 2012

The diversity of
Pseudomonas aeruginosa
bacteriophages was investigated using a collection of 68 phages isolated from Central Mexico. Most of the phages carried double-stranded DNA (dsDNA) genomes and were classified into 12 species. Comparison of the genomes of selected archetypal phages with extant sequences in GenBank resulted in the identification of six novel species. This finding increased the group diversity by ∼30%. The great diversity of phage species could be related to the ubiquitous nature of
P. aeruginosa
.
Diversity of Listeria Species in Urban and Natural Environments
Authors: Sauders Brian D. , Overdevest Jon , Fortes Esther , Windham Katy , Schukken Ynte , Lembo Arthur , Wiedmann Martin
Published: April 2012

A total of 442
Listeria
isolates, including 234
Listeria seeligeri
, 80
L. monocytogenes
, 74
L. welshimeri
, 50
L. innocua
, and 4
L. marthii
isolates, were obtained from 1,805 soil, water, and other environmental samples collected over 2 years from four urban areas and four areas representing natural environments.
Listeria
spp. showed similar prevalences in samples from natural (23.4%) and urban (22.3%) environments. While
L. seeligeri
and
L. welshimeri
were significantly associated with natural environments (
P
≤ 0.0001),
L. innocua
and
L. monocytogenes
were significantly associated with urban environments (
P
≤ 0.0001). Sequencing of
sigB
for all isolates revealed 67 allelic types with a higher level of allelic diversity among isolates from urban environments. Some
Listeria
spp. and
sigB
allelic types showed significant associations with specific urban and natural areas. Nearest-neighbor analyses also showed that certain
Listeria
spp. and
sigB
allelic types were spatially clustered within both natural and urban environments, and there was evidence that these species and allelic types persisted over time in specific areas. Our data show that members of the genus
Listeria
not only are common in urban and natural environments but also show species- and subtype-specific associations with different environments and areas. This indicates that
Listeria
species and subtypes within these species may show distinct ecological preferences, which suggests (i) that molecular source-tracking approaches can be developed for
Listeria
and (ii) that detection of some
Listeria
species may not be a good indicator for
L. monocytogenes
.
High-Throughput Screening for Streptomyces Antibiotic Biosynthesis Activators
Authors: Chen Li , Wang Yemin , Guo Hang , Xu Min , Deng Zixin , Tao Meifeng
Published: April 2012

A genomic cosmid library of
Streptomyces clavuligerus
was constructed and transferred efficiently by conjugation to
Streptomyces lividans
, and 12 distinct groups of overlapping cosmid clones that activated the silent actinorhodin biosynthesis gene cluster were identified. This generally applicable high-throughput screening procedure greatly facilitates the identification of antibiotic biosynthesis activators.
Increase in Furfural Tolerance in Ethanologenic Escherichia coli LY180 by Plasmid-Based Expression of
thyA
Authors: Zheng Huabao , Wang Xuan , Yomano Lorraine P. , Shanmugam Keelnatham T. , Ingram Lonnie O.
Published: April 2012

Furfural is an inhibitory side product formed during the depolymerization of hemicellulose by mineral acids. Genomic libraries from three different bacteria (
Bacillus subtilis
YB886,
Escherichia coli
NC3, and
Zymomonas mobilis
CP4) were screened for genes that conferred furfural resistance on plates. Beneficial plasmids containing the
thyA
gene (coding for thymidylate synthase) were recovered from all three organisms. Expression of this key gene in the
de novo
pathway for dTMP biosynthesis improved furfural resistance on plates and during fermentation. A similar benefit was observed by supplementation with thymine, thymidine, or the combination of tetrahydrofolate and serine (precursors for 5,10-methylenetetrahydrofolate, the methyl donor for ThyA). Supplementation with deoxyuridine provided a small benefit, and deoxyribose was of no benefit for furfural tolerance. A combination of thymidine and plasmid expression of
thyA
was no more effective than either alone. Together, these results demonstrate that furfural tolerance is increased by approaches that increase the supply of pyrimidine deoxyribonucleotides. However, ThyA activity was not directly affected by the addition of furfural. Furfural has been previously shown to damage DNA in
E. coli
and to activate a cellular response to oxidative damage in yeast. The added burden of repairing furfural-damaged DNA in
E. coli
would be expected to increase the cellular requirement for dTMP. Increased expression of
thyA
(
E. coli
,
B. subtilis
, or
Z. mobilis
), supplementation of cultures with thymidine, and supplementation with precursors for 5,10-methylenetetrahydrofolate (methyl donor) are each proposed to increase furfural tolerance by increasing the availability of dTMP for DNA repair.
Dioxygenation of the Biphenyl Dioxygenation Product
Authors: Overwin Heike , González Myriam , Méndez Valentina , Seeger Michael , Wray Victor , Hofer Bernd
Published: April 2012

Two biphenyl dioxygenases (BphAs) were shown to catalyze dioxygenation of biphenyldienediol in the nonoxidized ring to form the respective symmetrical biphenyl-bis-dienediol. This novel metabolite served as a growth substrate for both BphA source strains. Its catabolism through the upper
bph
pathway of
Burkholderia xenovorans
LB400 was analyzed.
Insights into the Maturation of Hyperthermophilic Pyrolysin and the Roles of Its N-Terminal Propeptide and Long C-Terminal Extension
Authors: Dai Zheng , Fu Heting , Zhang Yufeng , Zeng Jing , Tang Bing , Tang Xiao-Feng
Published: April 2012

Pyrolysin-like proteases from hyperthermophiles are characterized by large insertions and long C-terminal extensions (CTEs). However, little is known about the roles of these extra structural elements or the maturation of these enzymes. Here, the recombinant proform of
Pyrococcus furiosus
pyrolysin (Pls) and several N- and C-terminal deletion mutants were successfully expressed in
Escherichia coli
. Pls was converted to mature enzyme (mPls) at high temperatures via autoprocessing of both the N-terminal propeptide and the C-terminal portion of the long CTE, indicating that the long CTE actually consists of the C-terminal propeptide and the C-terminal extension (CTEm), which remains attached to the catalytic domain in the mature enzyme. Although the N-terminal propeptide deletion mutant PlsΔN displayed weak activity, this mutant was highly susceptible to autoproteolysis and/or thermogenic hydrolysis. The N-terminal propeptide acts as an intramolecular chaperone to assist the folding of pyrolysin into its thermostable conformation. In contrast, the C-terminal propeptide deletion mutant PlsΔC199 was converted to a mature form (mPlsΔC199), which is the same size as but less stable than mPls, suggesting that the C-terminal propeptide is not essential for folding but is important for pyrolysin hyperthermostability. Characterization of the full-length (mPls) and CTEm deletion (mPlsΔC740) mature forms demonstrated that CTEm not only confers additional stability to the enzyme but also improves its catalytic efficiency for both proteineous and small synthetic peptide substrates. Our results may provide important clues about the roles of propeptides and CTEs in the adaptation of hyperthermophilic proteases to hyperthermal environments.
Identification of the Promoter in the Intergenic Region between
orf1
and
cry8Ea1
Controlled by Sigma H Factor
Authors: Du Lixin , Qiu Lili , Peng Qi , Lereclus Didier , Zhang Jie , Song Fuping , Huang Dafang
Published: April 2012

Bacillus thuringiensis
Cry8Ea toxin is specifically toxic to larvae of the Asian cockchafer,
Holotrichia parallela
. Here we investigated the mechanism of transcriptional regulation of the
cry8Ea1
gene. Reverse transcription-PCR (RT-PCR) results indicated that
cry8Ea1
and an upstream gene (
orf1
) were cotranscribed. Transcriptional fusions with the
lacZ
gene demonstrated that transcription of the
cry8Ea1
gene started from two promoters: P

orf1

, which is located upstream of the
orf1
gene, and P

cry8E

, located in the intergenic region mapping between
orf1
and
cry8Ea1
. Of the known, similar
orf1-cry
operons, this is the first report of the existence of a promoter in the intergenic region between the
orf1
and
cry
genes. The transcriptional activity of P

orf1

was found during sporulation in
B. thuringiensis
subsp.
kurstaki
HD-73 and was almost abolished in the
sigE
mutant, while the transcriptional activity of P

cry8E

was detected after the end of the exponential phase in HD-73 and was considerably lower in the
sigH
mutant. The transcription start sites generated by the two
cry8Ea1
promoters were determined by the 5′ -SMARTer rapid amplification of cDNA ends (RACE) method. The −35 and −10 regions of P

orf1

and P

cry8E

showed high sequence similarity with the σ
E
and σ
H
promoters, respectively. These results indicated that P

orf1

is controlled by the σ
E
factor and P

cry8E

by the σ
H
factor.
Complete Sequence Analysis of Two Methanotroph-Specific
repABC
-Containing Plasmids from Methylocystis sp. Strain SC2
Authors: Dam Bomba , Kube Michael , Dam Somasri , Reinhardt Richard , Liesack Werner
Published: April 2012

The complete nucleotide sequences of two large, low-copy-number plasmids of 229.6 kb (pBSC2-1) and 143.5 kb (pBSC2-2) were determined during assembly of the whole-genome shotgun sequences of the methane-oxidizing bacterium
Methylocystis
sp. strain SC2. The physical existence of the two plasmids in strain SC2 was confirmed by pulsed-field gel electrophoresis followed by Southern hybridization. Both plasmids have a conserved replication module of the
repABC
system and carry genes involved in their faithful maintenance and conjugation. In addition, they contain genes that might be involved in essential metabolic processes. These include several heavy metal resistance genes and copper transport genes in pBSC2-1 and a complete nitrous oxide reductase operon and a
pmoC
singleton in pBSC2-2, the latter encoding the PmoC subunit of particulate methane monooxygenase.
Novel Clade of Alphaproteobacterial Endosymbionts Associated with Stinkbugs and Other Arthropods
Authors: Matsuura Yu , Kikuchi Yoshitomo , Meng Xian Ying , Koga Ryuichi , Fukatsu Takema
Published: April 2012

Here we report a novel clade of secondary endosymbionts associated with insects and other arthropods. Seed bugs of the genus
Nysius
(Hemiptera: Lygaeidae) harbor the primary gammaproteobacterial symbiont
Schneideria nysicola
within a pair of bacteriomes in the abdomen. Our survey of
Nysius
species for their facultative bacterial associates consistently yielded a novel type of alphaproteobacterial 16S rRNA gene sequence in addition to those of
Wolbachia
. Diagnostic PCR survey of 343 individuals representing 24 populations of four
Nysius
species revealed overall detection rates of the alphaproteobacteria at 77.6% in
Nysius plebeius
, 87.7% in
Nysius
sp. 1, 81.0% in
Nysius
sp. 2, and 100% in
Nysius expressus
. Further survey of diverse stinkbugs representing 24 families, 191 species, and 582 individuals detected the alphaproteobacteria from an additional 12 species representing six families. Molecular phylogenetic analysis showed that the alphaproteobacteria from the stinkbugs form a distinct and coherent monophyletic group in the order
Rickettsiales
together with several uncharacterized endosymbionts from fleas and ticks. The alphaproteobacterial symbiont clade was allied to bacterial clades such as the endosymbionts of acanthamoebae, the endosymbionts of cnidarians, and
Midichloria
spp., the mitochondrion-associated endosymbionts of ticks.
In situ
hybridization and electron microscopy identified small filamentous bacterial cells in various tissues of
N. plebeius
, including the bacteriome and ovary. The concentrated localization of the symbiont cells at the anterior pole of oocytes indicated its vertical transmission route through host insect generations. The designation “
Candidatus
Lariskella arthropodarum” is proposed for the endosymbiont clade.
Prevalence of Clostridium difficile in Uncooked Ground Meat Products from Pittsburgh, Pennsylvania
Authors: Curry Scott R. , Marsh Jane W. , Schlackman Jessica L. , Harrison Lee H.
Published: April 2012

The prevalence of
Clostridium difficile
in retail meat samples has varied widely. The food supply may be a source for
C. difficile
infections. A total of 102 ground meat and sausage samples from 3 grocers in Pittsburgh, PA, were cultured for
C. difficile
. Brand A pork sausages were resampled between May 2011 and January 2012. Two out of 102 (2.0%) meat products initially sampled were positive for
C. difficile
; both were pork sausage from brand A from the same processing facility (facility A). On subsequent sampling of brand A products, 10/19 samples from processing facility A and 1/10 samples from 3 other facilities were positive for
C. difficile
. The isolates recovered were inferred ribotype 078, comprising 6 genotypes. The prevalence of
C. difficile
in retail meat may not be as high as previously reported in North America. When contamination occurs, it may be related to events at processing facilities.
Diversity and Partitioning of Bacterial Populations within the Accessory Nidamental Gland of the Squid Euprymna scolopes
Authors: Collins Andrew J. , LaBarre Brenna A. , Wong Won Brian S. , Shah Monica V. , Heng Steven , Choudhury Momena H. , Haydar Shahela A. , Santiago Jose , Nyholm Spencer V.
Published: April 2012

Microbial consortia confer important benefits to animal and plant hosts, and model associations are necessary to examine these types of host/microbe interactions. The accessory nidamental gland (ANG) is a female reproductive organ found among cephalopod mollusks that contains a consortium of bacteria, the exact function of which is unknown. To begin to understand the role of this organ, the bacterial consortium was characterized in the Hawaiian bobtail squid,
Euprymna scolopes
, a well-studied model organism for symbiosis research. Transmission electron microscopy (TEM) analysis of the ANG revealed dense bacterial assemblages of rod- and coccus-shaped cells segregated by morphology into separate, epithelium-lined tubules. The host epithelium was morphologically heterogeneous, containing ciliated and nonciliated cells with various brush border thicknesses. Hemocytes of the host's innate immune system were also found in close proximity to the bacteria within the tubules. A census of 16S rRNA genes suggested that
Rhodobacterales, Rhizobiales
, and
Verrucomicrobia
bacteria were prevalent, with members of the genus
Phaeobacter
dominating the consortium. Analysis of 454-shotgun sequencing data confirmed the presence of members of these taxa and revealed members of a fourth,
Flavobacteria
of the
Bacteroidetes
phylum. 16S rRNA fluorescent
in situ
hybridization (FISH) revealed that many ANG tubules were dominated by members of specific taxa, namely,
Rhodobacterales
,
Verrucomicrobia
, or
Cytophaga-Flavobacteria-Bacteroidetes
, suggesting symbiont partitioning to specific host tubules. In addition, FISH revealed that bacteria, including
Phaeobacter
species from the ANG, are likely deposited into the jelly coat of freshly laid eggs. This report establishes the ANG of the invertebrate
E. scolopes
as a model to examine interactions between a bacterial consortium and its host.
Abundance, Distribution, and Activity of Fe(II)-Oxidizing and Fe(III)-Reducing Microorganisms in Hypersaline Sediments of Lake Kasin, Southern Russia
Authors: Emmerich Maren , Bhansali Ankita , Lösekann-Behrens Tina , Schröder Christian , Kappler Andreas , Behrens Sebastian
Published: April 2012

The extreme osmotic conditions prevailing in hypersaline environments result in decreasing metabolic diversity with increasing salinity. Various microbial metabolisms have been shown to occur even at high salinity, including photosynthesis as well as sulfate and nitrate reduction. However, information about anaerobic microbial iron metabolism in hypersaline environments is scarce. We studied the phylogenetic diversity, distribution, and metabolic activity of iron(II)-oxidizing and iron(III)-reducing
Bacteria
and
Archaea
in pH-neutral, iron-rich salt lake sediments (Lake Kasin, southern Russia; salinity, 348.6 g liter
−1
) using a combination of culture-dependent and -independent techniques. 16S rRNA gene clone libraries for
Bacteria
and
Archaea
revealed a microbial community composition typical for hypersaline sediments. Most-probable-number counts confirmed the presence of 4.26 × 10
2
to 8.32 × 10
3
iron(II)-oxidizing
Bacteria
and 4.16 × 10
2
to 2.13 × 10
3
iron(III)-reducing microorganisms per gram dry sediment. Microbial iron(III) reduction was detected in the presence of 5 M NaCl, extending the natural habitat boundaries for this important microbial process. Quantitative real-time PCR showed that 16S rRNA gene copy numbers of total
Bacteria
, total
Archaea
, and species dominating the iron(III)-reducing enrichment cultures (relatives of
Halobaculum gomorrense
,
Desulfosporosinus lacus
, and members of the
Bacilli
) were highest in an iron oxide-rich sediment layer. Combined with the presented geochemical and mineralogical data, our findings suggest the presence of an active microbial iron cycle at salt concentrations close to the solubility limit of NaCl.