bluuebunny/crossref_metadata_2025 huggingface dataset:
Patterns of haemosporidian prevalence along a range expansion in introduced Kenyan house sparrowsPasser domesticus
Authors: Coon Courtney A. C. , Martin Lynn B.
Published: November 2013

Avian haemosporidian infections (of the generaHaemoproteus, PlasmodiumandLeucocytozoon) can regulate passerine populations. Thus, reduction in the number of avian haemosporidian infections in a population, for example in recently introduced hosts, may facilitate host establishment or spread (i.e. enemy release). Alternatively, colonizers could decrease competitive ability of native individuals in the novel range by increasing the prevalence of avian haemosporidians in that native passerine community (i.e. novel weapons). However, whether either or both of these phenomena will occur is difficult to predict because infection risk can be highly heterogeneous and dependent upon the interaction of biotic and abiotic factors at the microclimate level, especially because of the important role of vectors for these parasites. Here, we describe which factors best predicted avian haemosporidian prevalence in populations of house sparrowsPasser domesticusintroduced to Kenya. House sparrows inhabit an invasion gradient in Kenya; they were introduced via the eastern port city of Mombasa in ˜ 1950 and have since spread west‐ward across the country. This range expansion gave us the opportunity to examine how parasite prevalence changes over small spatiotemporal scales and what role is played by environmental and individual traits. Among all individuals, body mass was the strongest predictor of infection, with larger house sparrows being more likely to be infected. At the population level, capture month, precipitation (higher prevalence with more rainfall), and population age (increasing prevalence with increasing time since introduction) were important risk factors. Overall, haemosporidian prevalence in Kenyan house sparrows appears to be more strongly associated with individual characteristics rather than with time since introduction as was predicted, though this does not necessarily rule out a role for enemy release or novel weapons in this system.
Wide Circumferential versus Individual Isolation of Pulmonary Veins Using the Endoscopic Ablation System
Authors: WISSNER ERIK , METZNER ANDREAS , REISSMANN BRUNO , RAUSCH PETER , BARDYSZEWSKI ALEKSANDER , LEMES CHRISTINE , TILZ ROLAND RICHARD , RILLIG ANDREAS , MATHEW SHIBU , DEISS SEBASTIAN , OUYANG FEIFAN , KUCK KARL‐HEINZ
Published: November 2013

Circumferential versus Individual Laserballoon PVI

Introduction

The endoscopic ablation system (EAS) allows for effective pulmonary vein isolation (PVI). The feasibility of wide circumferential as compared to individual PVI using the EAS has not been formally assessed.

Methods

Patients with paroxysmal or short‐persistent atrial fibrillation were assigned to individual PVI (group A) or wide circumferential PVI (group B). In group B, circumferential PVI was attempted only if the ipsilateral inferior PV was visualized while the ablation system targeted the superior PV and vice versa. Otherwise, individual PVI was performed.

Results

A total of 38 patients were enrolled (Group A: 20 patients, age 61 ± 7 years, LA‐diameter 43 ± 5 mm; Group B: 18 patients, age 62 ± 10 years, LA‐diameter 43 ± 4 mm). In group A, 20/20 (100%) right superior (RSPV) and inferior (RIPV) PVs, 18/19 (95%) left superior (LSPV) and inferior (LIPV) PVs, and 1/1 (100%) left common ostium (LCPV) were successfully isolated. First‐pass success rate was 95%, 85%, 68%, and 95% for the RSPV, RIPV, LSPV, and LIPV, respectively. Touch‐up radiofrequency ablation was required in 1/19 (5%) LSPV and LIPV. In group B, an attempt at circumferential PVI was feasible in 2/18 (11%) septal PVs and successful on first pass. Lateral circumferential PVI was attempted and successful on first‐pass in 7/13 (54%) LSPVs and LIPVs and 1/5 (20%) LCPVs.

Conclusions

Using the EAS in patients with AF, separate isolation of individual PVs rather than wide circumferential PVI should be the preferred ablation strategy.
Expression of interferon‐γ in decidual natural killer cells from women with hypertensive disorder complicating pregnancy
Authors: Zhou Juan , Xiao Xiao‐Min , Wu Ying‐Hua
Published: November 2013

Aim

Hypertensive disorder complicating pregnancy (HDCP) is one of the most frequent and serious pregnancy‐related diseases, which is closely related to disorders of the maternal immune system, especially the local immune microenvironment of the maternal–fetal interface. Uterine decidual natural killer (dNK) cells are the major immune cells in the maternal–fetal interface and they play an important role in establishing and maintaining a normal pregnancy. The aim of this study was to investigate the phenotype and function of dNK cells from women with HDCP.

Material and Methods

Decidual tissues were collected from women with normal pregnancy (normal control group, n = 15 cases) and HDCP (HDCP group, n = 20 cases), respectively. The mononuclear cells were extracted from tissues and flow cytometry (FCM) was utilized to sort out dNK cells. The phenotypes of dNK cells (CD56brightCD16−CD3− vs CD56dimCD16+CD3−) were detected by FCM. After being co‐cultured with Phorbol 12‐myristate 13‐acetate, ionomycin and monensin, the expression level of interferon (IFN)‐γ in the dNK cells was detected by FCM.

Results

The phenotypes of dNK cells from the two groups were dominated by the CD56brightCD16−CD3− subset, with no significant statistical difference (P < 0.05). The expression level of IFN‐γ in the dNK cells from women with HDCP was on a lower trend than those from women with normal pregnancy, having significant statistical difference (P = 0.000 < 0.05).

Conclusions

Our results indicated that although the phenotype of dNK cells from women with HDCP is of no difference, their functions are abnormal. Impaired cell function leads to a lower expression level of IFN‐γ and this may account for one of the pathogeneses of HDCP.
Genetic delineation between and within the widespread coccolithophore morpho‐species Emiliania huxleyi and Gephyrocapsa oceanica (Haptophyta)
Authors: Bendif El Mahdi , Probert Ian , Carmichael Margaux , Romac Sarah , Hagino Kyoko , de Vargas Colomban
Published: November 2013

Emiliania huxleyi and Gephyrocapsa oceanica are abundant coccolithophore morpho‐species that play key roles in ocean carbon cycling due to their importance as both primary producers and cal‐cifiers. Global change processes such as ocean acidification impact these key calcifying species. The physiology of E. huxleyi, a developing model species, has been widely studied, but its genetic delineation from G. oceanica remains unclear due to a lack of resolution in classical genetic markers. Using nuclear (18S rDNA and 28S rDNA), mitochondrial (cox1, cox2, cox3, rpl16, and dam), and plastidial (16S rDNA, rbcL, tufA, and petA) DNA markers from 99 E. huxleyi and 44 G. oceanica strains, we conducted a multigene/multistrain survey to compare the suitability of different markers for resolving phylogenetic patterns within and between these two morpho‐species. The nuclear genes tested did not provide sufficient resolution to discriminate between the two morpho‐species that diverged only 291Kya. Typical patterns of incomplete lineage sorting were generated in phylogenetic analyses using plastidial genes. In contrast, full morpho‐species delineation was achieved with mitochondrial markers and common intra‐morpho‐species phylogenetic patterns were observed despite differing rates of DNA substitution. Mitochondrial genes are thus promising barcodes for distinguishing these coccolithophore morpho‐species, in particular in the context of environmental monitoring.
Genome skimming reveals the origin of the Jerusalem Artichoke tuber crop species: neither from Jerusalem nor an artichoke
Authors: Bock Dan G. , Kane Nolan C. , Ebert Daniel P. , Rieseberg Loren H.
Published: November 2013

The perennial sunflower Helianthus tuberosus, known as Jerusalem Artichoke or Sunchoke, was cultivated in eastern North America before European contact. As such, it represents one of the few taxa that can support an independent origin of domestication in this region. Its tubers were adopted as a source of food and forage when the species was transferred to the Old World in the early 1600s, and are still used today.

Despite the cultural and economic importance of this tuber crop species, its origin is debated. Competing hypotheses implicate the occurrence of polyploidization with or without hybridization, and list the annual sunflower H. annuus and five distantly related perennial sunflower species as potential parents.

Here, we test these scenarios by skimming the genomes of diverse populations of Jerusalem Artichoke and its putative progenitors. We identify relationships among Helianthus taxa using complete plastomes (151 551 bp), partial mitochondrial genomes (196 853 bp) and 35S (8196 bp) and 5S (514 bp) ribosomal DNA.

Our results refute the possibility that Jerusalem Artichoke is of H. annuus ancestry. We provide the first genetic evidence that this species originated recursively from perennial sunflowers of central‐eastern North America via hybridization between tetraploid Hairy Sunflower and diploid Sawtooth Sunflower.
Zebra and boxwork fabrics in hydrothermal dolomites of northern Canada: Indicators for dilational fracturing, dissolution or in situ replacement?
Authors: Morrow David W.
Published: November 2013

Zebra and boxwork fabrics in Manetoe and Presqu'ile hydrothermal dolomites provide critical data for discrimination between hypotheses for their origin. In a unique occurrence, sets of weakly imbricated, decimetre‐sized curvilinear lenticles of white dolospar are developed within sub‐metre sized tongues of greyish‐white dolomitized crinoidal packstone and grainstone. This nascent zebra fabric has developed along wavy to nodular intra‐bed sedimentary partings. Primary bedding can be traced through dolomitized masses containing these fabrics, into the surrounding undolomitized limestone. All zebra and boxwork fabrics are confined within single beds, consistent with an early burial time of origin. No change in bed thickness occurs across zebra or boxwork fabrics within beds; this indicates a dissolutional, rather than a dilational, origin for the creation of pore space partly cemented with white dolospar. The dolomitized groundmass displays an abruptly gradational or sharp transition to centripetal saddle dolomite cement, which partially to nearly completely, occludes vugs. Circulation of geothermally heated hypersaline Devonian Elk Point basinal sea water brines led to dissolution and replacive dolomitization of limestone adjacent to vugs, and near‐contemporaneous precipitation of white dolospar within dissolutional vugs, consistent with geochemical simulations. The presence of downward‐extending galleries of white dolospar‐cemented solution‐collapse breccia provides further support for an interpretation of regional thermally driven convection of hydrothermal evaporative sea water brines across a broad area of northern Canada. The absence of gases under pressure in vacuoles within fluid inclusions from Manetoe and Presqu'ile dolospars is also more consistent with a dissolutional and contemporaneous dolomitization origin for these fabrics, rather than an origin involving dilational fracturing for space creation and dolospar precipitation. The ubiquitous presence of zebra and boxwork fabrics in hydrothermal dolomite reservoirs indicates that they are not confined fault zones and instead occur wherever precursor limestones had relatively greater porosity and permeability prior to dolomitization.
Short‐Term Pain, Long‐Term Gain? The Effects of IMF Economic Reform Programs on Public Health Performance
Authors: Hoddie Matthew , Hartzell Caroline A.
Published: November 2013

Objectives

In this study, we evaluate the effects of the International Monetary Fund's structural adjustment programs (SAPs) on the public health performance of countries. We test the claim made by proponents of SAPs that although these programs may produce short‐term hardship for the countries adopting them, they will generate positive developmental effects in the long term.

Methods

Our study draws on a global data set and employs a model that takes into account the potential for selection bias in the adoption of SAPs by states.

Results

The central finding of the article is that SAPs in the short term raise the exposure of populations to conditions that increase incidences of disability and death. Contrary to the assertions made by the advocates of SAPs, we also find evidence that these programs have attenuated but still harmful effect on public health performance in the long term.

Conclusions

This study highlights the negative influences of SAPs on public health and suggests that a need exists to reevaluate the claims that have been made regarding the developmental effects of these programs.
A Systematic Review and Meta‐Analysis of Phase I Inactivated Vaccines to Reduce Shedding of Coxiella burnetii From Sheep and Goats From Routes of Public Health Importance
Authors: O'Neill T. J. , Sargeant J. M. , Poljak Z.
Published: November 2013

Q fever in humans and coxiellosis in livestock are both caused by Coxiella burnetii. The public health importance of vaccination against C. burnetii shedding from sheep and goats was evaluated using systematic review and meta‐analysis to provide evidence for policy direction to prevent potential zoonotic spread. Publications reporting shedding of C. burnetii in vaginal and uterine secretions, milk, placenta and faeces were included. A single observational (one goat) and seven experimental (four goat and three sheep) vaccine studies were included in the review. No relevant publications on other interventions were identified. Random effects meta‐analyses were performed for the risk of shedding in individuals in the control and vaccinated groups and for the mean difference in the level of bacterial shedding in sheep and goats stratified by age and previous exposure status. Limited data were available for further analytic evaluation. From the pooled analysis, an inactivated phase I vaccine significantly reduced the risk of shedding from uterine (RR = 0.10; 95%CI 0.05–0.20) secretions in previously sensitized goats. Individual studies reported significant risk reduction in milk (RR = 0.03; 95%CI 0.01–0.26), vaginal secretions (RR = 0.40; 95%CI 0.22–0.75) and faeces (RR = 0.79; 95%CI 0.63–0.97) from naïve goats. The pooled mean levels of bacteria shed from placental [mean difference (MD = −5.24 Log10; 95%CI −6.75 to −3.7)] and vaginal (MD = −1.78 Log10; 95%CI −2.19 to −1.38) routes were significantly decreased in vaccinated naïve goats compared with controls. Shedding through all other routes from vaccinated goats was not significantly different than shedding from control goats. No effect of vaccination was found on the risk of shedding or the mean level of shedding in vaccinated sheep compared with control sheep. Our conclusions are based on a limited amount of data with variable risk of systematic error.
Subunit‐specific inhibition of acid sensing ion channels by stomatin‐like protein 1
Authors: Kozlenkov Alexey , Lapatsina Liudmila , Lewin Gary R. , Smith Ewan St. John
Published: November 2013

Key points

Stomatin‐like protein 1 (STOML1) was found both at the plasma membrane and associated with vesicles in the neurites of dorsal root ganglia (DRG) neurones.

We found that STOML1 modulates ASIC1a and ASIC3. In the presence of STOML1 acid gated currents carried by ASIC1a were decreased and ASIC3 currents showed accelerated inactivation; STOML1 had no effects on other ASICs.

Among the stomatin family, only STOML1 has a sterol carrier protein‐2 domain and removal of this domain prevented inhibition of ASIC1a currents.

We generated a mouse with a β‐galactosidase‐neomycin cassette gene‐trap reporter driven from the STOML1 gene locus to demonstrate that STOML1 is expressed by approximately half of all DRG neurones.

Whole‐cell electrophysiology recordings from DRG neurones from STOML1 null mutant mice showed on average larger proton‐gated currents compared to neurones from wild‐type mice.

There are five mammalian stomatin‐domain genes, all of which encode peripheral membrane proteins that can modulate ion channel function. Here we examined the ability of stomatin‐like protein 1 (STOML1) to modulate the proton‐sensitive members of the acid‐sensing ion channel (ASIC) family. STOML1 profoundly inhibits ASIC1a, but has no effect on the splice variant ASIC1b. The inactivation time constant of ASIC3 is also accelerated by STOML1. We examined STOML1 null mutant mice with a β‐galactosidase‐neomycin cassette gene‐trap reporter driven from the STOML1 gene locus, which indicated that STOML1 is expressed in at least 50% of dorsal root ganglion (DRG) neurones. Patch clamp recordings from mouse DRG neurones identified a trend for larger proton‐gated currents in neurones lacking STOML1, which was due to a contribution of effects upon both transient and sustained currents, at different pH, a finding consistent with an endogenous inhibitory function for STOML1.
Role of plasma enhanced atomic layer deposition reactor wall conditions on radical and ion substrate fluxes
Authors: Sowa Mark J.
Published: November 2013

Chamber wall conditions, such as wall temperature and film deposits, have long been known to influence plasma source performance on thin film processing equipment. Plasma physical characteristics depend on conductive/insulating properties of chamber walls. Radical fluxes depend on plasma characteristics as well as wall recombination rates, which can be wall material and temperature dependent. Variations in substrate delivery of plasma generated species (radicals, ions, etc.) impact the resulting etch or deposition process resulting in process drift. Plasma enhanced atomic layer deposition is known to depend strongly on substrate radical flux, but film properties can be influenced by other plasma generated phenomena, such as ion bombardment. In this paper, the chamber wall conditions on a plasma enhanced atomic layer deposition process are investigated. The downstream oxygen radical and ion fluxes from an inductively coupled plasma source are indirectly monitored in temperature controlled (25–190 °C) stainless steel and quartz reactors over a range of oxygen flow rates. Etch rates of a photoresist coated quartz crystal microbalance are used to study the oxygen radical flux dependence on reactor characteristics. Plasma density estimates from Langmuir probe ion saturation current measurements are used to study the ion flux dependence on reactor characteristics. Reactor temperature was not found to impact radical and ion fluxes substantially. Radical and ion fluxes were higher for quartz walls compared to stainless steel walls over all oxygen flow rates considered. The radical flux to ion flux ratio is likely to be a critical parameter for the deposition of consistent film properties. Reactor wall material, gas flow rate/pressure, and distance from the plasma source all impact the radical to ion flux ratio. These results indicate maintaining chamber wall conditions will be important for delivering consistent results from plasma enhanced atomic layer deposition systems.
Generation of virtual monochromatic CBCT from dual kV/MV beam projectionsa)
Authors: Li Hao , Liu Bo , Yin Fang‐Fang
Published: November 2013

Purpose:

To develop a novel on‐board imaging technique which allows generation of virtual monochromatic (VM) cone‐beam CT (CBCT) with a selected energy from combined kilovoltage (kV)/megavoltage (MV) beam projections.

Methods:

With the current orthogonal kV/MV imaging hardware equipped in modern linear accelerators, both MV projections (from gantry angle of 0°–100°) and kV projections (90°–200°) were acquired as gantry rotated a total of 110°. A selected range of overlap projections between 90° to 100° were then decomposed into two material projections using experimentally determined parameters from orthogonally stacked aluminum and acrylic step‐wedges. Given attenuation coefficients of aluminum and acrylic at a predetermined energy, one set of VM projections could be synthesized from two corresponding sets of decomposed projections. Two linear functions were generated using projection information at overlap angles to convert kV and MV projections at nonoverlap angles to approximate VM projections for CBCT reconstruction. The contrast‐to‐noise ratios (CNRs) were calculated for different inserts in VM CBCTs of a CatPhan phantom with various selected energies and compared with those in kV and MV CBCTs. The effect of overlap projection number on CNR was evaluated. Additionally, the effect of beam orientation was studied by scanning the CatPhan sandwiched with two 5 cm solid‐water phantoms on both lateral sides and an electronic density phantom with two metal bolt inserts.

Results:

Proper selection of VM energy [30 and 40 keV for low‐density polyethylene (LDPE), polymethylpentene, 2 MeV for Delrin] provided comparable or even better CNR results as compared with kV or MV CBCT. An increased number of overlap kV and MV projection demonstrated only marginal improvements of CNR for different inserts (with the exception of LDPE) and therefore one projection overlap was found to be sufficient for the CatPhan study. It was also evident that the optimal CBCT image quality was achieved when MV beams penetrated through the heavy attenuation direction of the object.

Conclusions:

A novel technique was developed to generate VM CBCTs from kV/MV projections. This technique has the potential to improve CNR at selected VM energies and to suppress artifacts at appropriate beam orientations.
Compensator models for fluence field modulated computed tomography
Authors: Bartolac Steven , Jaffray David
Published: November 2013

Purpose:

Fluence field modulated computed tomography (FFMCT) presents a novel approach for acquiring CT images, whereby a patient model guides dynamically changing fluence patterns in an attempt to achieve task‐based, user‐prescribed, regional variations in image quality, while also controlling dose to the patient. This work aims to compare the relative effectiveness of FFMCT applied to different thoracic imaging tasks (routine diagnostic CT, lung cancer screening, and cardiac CT) when the modulator is subject to limiting constraints, such as might be present in realistic implementations.

Methods:

An image quality plan was defined for a simulated anthropomorphic chest slice, including regions of high and low image quality, for each of the thoracic imaging tasks. Modulated fluence patterns were generated using a simulated annealing optimization script, which attempts to achieve the image quality plan under a global dosimetric constraint. Optimization was repeated under different types of modulation constraints (e.g., fixed or gantry angle dependent patterns, continuous or comprised of discrete apertures) with the most limiting case being a fixed conventional bowtie filter. For each thoracic imaging task, an image quality map (IQMsd) representing the regionally varying standard deviation is predicted for each modulation method and compared to the prescribed image quality plan as well as against results from uniform fluence fields. Relative integral dose measures were also compared.

Results:

Each IQMsd resulting from FFMCT showed improved agreement with planned objectives compared to those from uniform fluence fields for all cases. Dynamically changing modulation patterns yielded better uniformity, improved image quality, and lower dose compared to fixed filter patterns with optimized tube current. For the latter fixed filter cases, the optimal choice of tube current modulation was found to depend heavily on the task. Average integral dose reduction compared to a uniform fluence field ranged from 10% using a bowtie filter to 40% or greater using an idealized modulator.

Conclusions:

The results support that FFMCT may achieve regionally varying image quality distributions in good agreement with user‐prescribed values, while limiting dose. The imposition of constraints inhibits dose reduction capacity and agreement with image quality plans but still yields significant improvement over what is afforded by conventional dose minimization techniques. These results suggest that FFMCT can be implemented effectively even when the modulator has limited modulation capabilities.
Science Signaling
Podcast: 19 November 2013
Authors: Gelvin Stanton B. , VanHook Annalisa M.
Published: November 2013

Bacterially produced cytokinins promote infection by repressing a transcription factor in host plants.
What to Expect When Mom Is Infected
Authors: Berndt Jason D.
Published: November 2013

Maternal infection increases the number of neural progenitor cells in adult offspring.
Keeping Bone Where Bone Belongs
Authors: Ferrarelli Leslie K.
Published: November 2013

Activating or inactivating mutations in a Gα
s
can trigger inappropriate bone formation.
Slipping the NET
Authors: Ash Caroline
Published: November 2013

Enzymes secreted by a bacterial pathogen turn immune responses against themselves.
The Root of the Problem
Authors: Hines Pamela J.
Published: November 2013

Restrained growth of a key root tip region involves an interplay between hormonal activation and transcription factor levels.
In Vitro
Responses of Acinetobacter baumannii to Two- and Three-Drug Combinations following Exposure to Colistin and Doripenem
Authors: Oleksiuk Louise M. , Nguyen M. Hong , Press Ellen G. , Updike Cassaundra L. , O'Hara Jessica A. , Doi Yohei , Clancy Cornelius J. , Shields Ryan K.
Published: November 2013

We compared
in vitro
killing of colistin, doripenem, and sulbactam by time-kill methods against
Acinetobacter baumannii
isolates collected from patients before and after colistin-doripenem treatment (initial and recurrent isolates, respectively). Colistin-doripenem bactericidal activity against recurrent isolates was attenuated (mean log
10
kill, −5.74 versus −2.88;
P
= 0.01) but was restored by adding sulbactam. Doripenem MICs rather than colistin MICs correlated with the activity of colistin-doripenem. Among colistin-resistant isolates, colistin-doripenem-sulbactam combinations achieved greater killing than colistin-doripenem alone (−5.65 versus −2.43;
P
= 0.04).
Histatin 5-Spermidine Conjugates Have Enhanced Fungicidal Activity and Efficacy as a Topical Therapeutic for Oral Candidiasis
Authors: Tati Swetha , Li Rui , Puri Sumant , Kumar Rohitashw , Davidow Peter , Edgerton Mira
Published: November 2013

Oropharyngeal candidiasis (OPC) is caused by the opportunistic fungi
Candida albicans
and is prevalent in immunocompromised patients, individuals with dry mouth, or patients with prolonged antibiotic therapies that reduce oral commensal bacteria. Human salivary histatins, including histatin 5 (Hst 5), are small cationic proteins that are the major source of fungicidal activity of saliva. However, Hsts are rapidly degraded
in vivo
, limiting their usefulness as therapeutic agents despite their lack of toxicity. We constructed a conjugate peptide using spermidine (Spd) linked to the active fragment of Hst 5 (Hst 5
4–15
), based upon our findings that
C. albicans
spermidine transporters are required for Hst 5 uptake and fungicidal activity. We found that Hst 5
4–15
-Spd was significantly more effective in killing
C. albicans
and
Candida glabrata
than Hst 5 alone in both planktonic and biofilm growth and that Hst 5
4–15
-Spd retained high activity in both serum and saliva. Hst 5
4–15
-Spd was not bactericidal against streptococcal oral commensal bacteria and had no hemolytic activity. We tested the effectiveness of Hst 5
4–15
-Spd
in vivo
by topical application to tongue surfaces of immunocompromised mice with OPC. Mice treated with Hst 5
4–15
-Spd had significant clearance of candidal tongue lesions macroscopically, which was confirmed by a 3- to 5-log fold reduction of
C. albicans
colonies recovered from tongue tissues. Hst 5
4–15
-Spd conjugates are a new class of peptide-based drugs with high selectivity for fungi and potential as topical therapeutic agents for oral candidiasis.
Contemporary Diversity of β-Lactamases among Enterobacteriaceae in the Nine U.S. Census Regions and Ceftazidime-Avibactam Activity Tested against Isolates Producing the Most Prevalent β-Lactamase Groups
Authors: Castanheira Mariana , Farrell Sarah E. , Krause Kevin M. , Jones Ronald N. , Sader Helio S.
Published: November 2013

Escherichia coli
(328 isolates),
Klebsiella pneumoniae
(296),
Klebsiella oxytoca
(44), and
Proteus mirabilis
(33) isolates collected during 2012 from the nine U.S. census regions and displaying extended-spectrum-β-lactamase (ESBL) phenotypes were evaluated for the presence of β-lactamase genes, and antimicrobial susceptibility profiles were analyzed. The highest ESBL rates were noted for
K. pneumoniae
(16.0%, versus 4.8 to 11.9% for the other species) and in the Mid-Atlantic and West South Central census regions. CTX-M group 1 (including CTX-M-15) was detected in 303 strains and was widespread throughout the United States but was more prevalent in the West South Central, Mid-Atlantic, and East North Central regions. KPC producers (118 strains [112
K. pneumoniae
strains]) were detected in all regions and were most frequent in the Mid-Atlantic region (58 strains). Thirteen KPC producers also carried
bla
CTX-M
. SHV genes encoding ESBL activity were detected among 176 isolates. Other β-lactamase genes observed were CTX-M group 9 (72 isolates), FOX (10), TEM ESBL (9), DHA (7), CTX-M group 2 (3), NDM-1 (2 [Colorado]), and CTX-M groups 8 and 25 (1). Additionally, 62.9% of isolates carried ≥2 β-lactamase genes. KPC producers were highly resistant to multiple agents, but ceftazidime-avibactam (MIC
50/90
, 0.5/2 μg/ml) and tigecycline (MIC
50/90
, 0.5/1 μg/ml) were the most active agents tested. Overall, meropenem (MIC
50
, ≤0.06 μg/ml), ceftazidime-avibactam (MIC
50
, 0.12 to 0.5 μg/ml), and tigecycline (MIC
50
, 0.12 to 2 μg/ml) were the most active antimicrobials when tested against this collection. NDM-1 producers were resistant to all β-lactams tested. The diversity and increasing prevalence of β-lactamase-producing
Enterobacteriaceae
have been documented, and ceftazidime-avibactam was very active against the vast majority of β-lactamase-producing strains isolated from U.S. hospitals.
Antimicrobial-Related Severe Adverse Events during Treatment of Bone and Joint Infection Due to Methicillin-Susceptible Staphylococcus aureus
Authors: Valour Florent , Karsenty Judith , Bouaziz Anissa , Ader Florence , Tod Michel , Lustig Sébastien , Laurent Frédéric , Ecochard René , Chidiac Christian , Ferry Tristan
Published: November 2013

Prolonged antimicrobial therapy is recommended for methicillin-susceptible
Staphylococcus aureus
(MSSA) bone and joint infections (BJI), but its safety profile and risk factors for severe adverse events (SAE) in clinical practice are unknown. We addressed these issues in a retrospective cohort study (2001 to 2011) analyzing antimicrobial-related SAE (defined according to the Common Terminology Criteria for Adverse Events) in 200 patients (male, 62%; median age, 60.8 years [interquartile range {IQR}, 45.5 to 74.2 years]) with MSSA BJI admitted to a reference regional center with acute (66%) or chronic arthritis (7.5%), osteomyelitis (9.5%), spondylodiscitis (16%), or orthopedic device-related infections (67%). These patients received antistaphylococcal therapy for a median of 26.6 weeks (IQR, 16.8 to 37.8 weeks). Thirty-eight SAE occurred in 30 patients (15%), with a median time delay of 34 days (IQR, 14.75 to 60.5 days), including 10 patients with hematologic reactions, 9 with cutaneomucosal reactions, 6 with acute renal injuries, 4 with hypokalemia, and 4 with cholestatic hepatitis. The most frequently implicated antimicrobials were antistaphylococcal penicillins (ASP) (13 SAE/145 patients), fluoroquinolones (12 SAE/187 patients), glycopeptides (9 SAE/101 patients), and rifampin (7 SAE/107 patients). Kaplan-Meier curves and stepwise binary logistic regression analyses were used to determine the risk factors for the occurrence of antimicrobial-related SAE. Age (odds ratio [OR], 1.479 for 10-year increase; 95% confidence interval [CI], 1.116 to 1.960;
P
= 0.006) appeared to be the only independent risk factor for SAE. In patients receiving ASP or rifampin, daily dose (OR, 1.028; 95% CI, 1.006 to 1.051;
P
= 0.014) and obesity (OR, 8.991; 95% CI, 1.453 to 55.627;
P
= 0.018) were associated with the occurrence of SAE. The high rate of SAE and their determinants highlighted the importance of the management and follow-up of BJI, with particular attention to be paid to older persons, especially for ASP dosage, and to rifampin dose adjustment in obese patients.
Loss of Sigma Factor RpoN Increases Intestinal Colonization of Vibrio parahaemolyticus in an Adult Mouse Model
Authors: Whitaker W. Brian , Richards Gary P. , Boyd E. Fidelma
Published: November 2013

Vibrio parahaemolyticus
is the leading cause of bacterial seafood-borne gastroenteritis worldwide, yet little is known about how this pathogen colonizes the human intestine. The alternative sigma factor RpoN/sigma-54 is a global regulator that controls flagellar synthesis, as well as a wide range of nonflagellar genes. We constructed an in-frame deletion mutation in
rpoN
(VP2670) in
V. parahaemolyticus
RIMD2210633, a clinical serogroup O3:K6 isolate, and examined the effects
in vivo
using a streptomycin-treated mouse model of colonization. We confirmed that deletion of
rpoN
rendered
V. parahaemolyticus
nonmotile, and it caused reduced biofilm formation and an apparent defect in glutamine synthetase production. In
in vivo
competition assays between the
rpoN
mutant and a wild-type RIMD2210633 strain marked with the β-galactosidase gene
lacZ
(WBWlacZ), the mutant colonized significantly more proficiently. Intestinal persistence competition assays also demonstrated that the
rpoN
mutant had enhanced fitness and outcompeted WBWlacZ. Mutants defective in the polar flagellum biosynthesis FliAP sigma factor also outcompeted WBWlacZ but not to the same level as the
rpoN
mutant, which suggested that lack of motility is not the sole cause of the fitness effect. In an
in vitro
growth competition assay in mouse intestinal mucus, the
rpoN
mutant also outcompeted the wild type and exhibited faster doubling times when grown in mucus and on individual components of mucus. Genes in the pathways for the catabolism of mucus sugars also had significantly higher expression levels in a Δ
rpoN
mutant than in the wild type. These data suggest that in
V. parahaemolyticus
, RpoN plays an important role in carbon utilization regulation, which may significantly affect host colonization.
Into the wild world of eosinophilic granuloma
Authors: Dhull Anil Kumar , Aggarwal Sumeet , Kaushal Vivek , Singh Sunita
Published: November 2013

Langerhans cell histiocytosis (LCH) is a group of relatively rare disease processes of reticuloendothelial system with an abnormal proliferation of Langerhans cells or their precursors. A wide spectrum of treatment modalities is available for LCH which includes surgery, curettage, steroids, radiation, various chemotherapy regimens, either in combination or alone have so far been adopted. There are several case reports of eosinophilic granuloma but for recurrent cases very few have discussed on treatment of LCH in adults. We report a case of a 21-year-old man presented with eosinophilic granuloma with recurrence of the lesions after 6 years of the initial treatment. Patient was treated with combination chemotherapy with three weekly CHOP regimen and the patient is disease free after 6 months of follow-up. Contrary to other reports, this case demonstrates that a good response with standard therapy is possible.
Patterns of sperm use in two populations of Red-sided Garter Snake (Thamnophis sirtalis parietalis) with long-term female sperm storage
Authors: Friesen Christopher R. , Mason Robert T. , Arnold Stevan J. , Estes Suzanne
Published: November 2013

Long-term sperm storage may contribute to postcopulatory sexual selection because it enhances the commingling of sperm from different males within the female reproductive tract, which is the prerequisite for sperm competition. Long-term sperm storage and multiple paternity has been documented in snakes, but the identity of the last potential father is usually unknown in studies demonstrating multiple paternity. Here we present the first study in Red-sided Garter Snakes (Thamnophis sirtalis parietalis (Say in James, 1832)) to use experimental population crosses to assess stored sperm usage, mate-order effects, and the potential for interpopulational gametic isolation. We found a high rate of multiple paternity indicative of ubiquitous long-term sperm storage in this system, and observed last-male sperm precedence in all families (n = 66). Postzygotic isolation was absent, and we observed only a weak asymmetry in pattern of sperm precedence in our population crosses.
ON THE COMPONENTS OF SPACES OF CURVES ON THE 2-SPHERE WITH GEODESIC CURVATURE IN A PRESCRIBED INTERVAL
Authors: SALDANHA NICOLAU C. , ZÜHLKE PEDRO
Published: November 2013

Let [Formula: see text] denote the set of all closed curves of class Cron the sphere S2whose geodesic curvatures are constrained to lie in (κ1, κ2), furnished with the Crtopology (for some r ≥ 2 and possibly infinite κ1< κ2). In 1970, J. Li ttle proved that the space [Formula: see text] of closed curves having positive geodesic curvature has three connected components. Let ρi= arccot κi(i = 1, 2). We show that [Formula: see text] has n connected components [Formula: see text] where [Formula: see text] and [Formula: see text] contains circles traversed j times (1 ≤ j ≤ n). The component [Formula: see text] also contains circles traversed (n - 1) + 2k times, and [Formula: see text] also contains circles traversed n + 2k times, for any k ∈ N. Further, each of [Formula: see text](n ≥ 3) is homeomorphic to SO3× E, where E is the separable Hilbert space. We also obtain a simple characterization of the components in terms of the properties of a curve and prove that [Formula: see text] is homeomorphic to [Formula: see text] whenever [Formula: see text].
THE PILLAR SWITCHINGS OF MAPPING CLASS GROUPS OF SURFACES
Authors: JEONG CHAN-SEOK , SONG YONGJIN
Published: November 2013

By gluing two copies of surface S0,g+2 along g + 1 holes, we get surface Sg,1. The pillar switching is a self-homeomorphism of Sg,1 which switches two pillars of surfaces by 180° horizontal rotation. We analyze the actions of the pillar switchings on π1Sg,1 and then give concrete expressions of the pillar switchings in terms of standard Dehn twists. The map ψ : Bg → Γg,1 sending the generators of Bg to the pillar switchings on Sg,1 is defined by extending the embedding Bg ↪ Γ0,(g+1),1. We show that this map is injective by analyzing the actions of pillar switchings on π1Sg,1. We also prove that this map induces a trivial homology homomorphism in the stable range. For the proof we use the categorical delooping method. We construct a suitable monoidal 2-functor from tile category to surface category and show that this functor thus induces a map of double loop spaces.
AN INVARIANCE PRINCIPLE FOR THE TAGGED PARTICLE PROCESS IN CONTINUUM WITH SINGULAR INTERACTION POTENTIAL
Authors: CONRAD FLORIAN , FATTLER TORBEN , GROTHAUS MARTIN
Published: November 2013

We consider the dynamics of a tagged particle in an infinite particle environment moving according to a stochastic gradient dynamics. For singular interaction potentials this tagged particle dynamics was constructed first in Ref. 7, using closures of pre-Dirichlet forms which were already proposed in Refs. 13 and 24. The environment dynamics and the coupled dynamics of the tagged particle and the environment were constructed separately. Here we continue the analysis of these processes: Proving an essential m-dissipativity result for the generator of the coupled dynamics from Ref. 7, we show that this dynamics does not only contain the environment dynamics (as one component), but is, given the latter, the only possible choice for being the coupled process. Moreover, we identify the uniform motion of the environment as the reversed motion of the tagged particle. (Since the dynamics are constructed as martingale solutions on configuration space, this is not immediate.) Furthermore, we prove ergodicity of the environment dynamics, whenever the underlying reference measure is a pure phase of the system. Finally, we show that these considerations are sufficient to apply Ref. 4 for proving an invariance principle for the tagged particle process. We remark that such an invariance principle was studied before in Ref. 13 for smooth potentials, and shown by abstract Dirichlet form methods in Ref. 24 for singular potentials.

Our results apply for a general class of Ruelle measures corresponding to potentials possibly having infinite range, a non-integrable singularity at 0 and a nontrivial negative part, and fulfill merely a weak differentiability condition on ℝd\{0}.
Diffeomorphometry and geodesic positioning systems for human anatomy
Authors: Miller Michael I. , Younes Laurent , Trouvé Alain
Published: November 2013

The Computational Anatomy project has largely been a study of large deformations within a Riemannian framework as an efficient point of view for generating metrics between anatomical configurations. This approach turns D'Arcy Thompson's comparative morphology of human biological shape and form into a metrizable space. Since the metric is constructed based on the geodesic length of the flows of diffeomorphisms connecting the forms, we call it diffeomorphometry. Just as importantly, since the flows describe algebraic group action on anatomical submanifolds and associated functional measurements, they become the basis for positioning information, which we term geodesic positioning. As well the geodesic connections provide Riemannian coordinates for locating forms in the anatomical orbit, which we call geodesic coordinates. These three components taken together — the metric, geodesic positioning of information, and geodesic coordinates — we term the geodesic positioning system. We illustrate via several examples in human and biological coordinate systems and machine learning of the statistical representation of shape and form.
Computer-Aided Simulations of Convective Heat Transfer in a Wedged Channel with Pin-Fins at Various Outlet Arrangements and Nonuniform Diameters
Authors: Zhou Qitao , Wang Xinmei , Li Lei , Xie Gongnan , Tong Fujuan
Published: November 2013

The turbine blade works at high thermal loads, especially the trailing edge of the blade due to the hot gas leakage flow. Pin-fins are well recognized as a kind of effective device to augment the convective heat transfer and effectively cool the trailing edge. In this paper, the cooling effectiveness of chordwise outlet pin-fins distance and inner pin fin diameter is, respectively, studied on the heat transfer and flow friction of the trailing edge of the blade with software CFX. A 90 deg turn cooling wedge passage with cylindrical pin-fins is used to model the trailing edge. Results show that the pin-fins distance at the outlet and the arithmetic arrangement of the inner pin-fins diameter both are vital factors to influence the cooling effectiveness in the trailing edge of the blade.
Fuzzy Filter-Based FDD Design for Non-Gaussian Stochastic Distribution Processes Using T-S Fuzzy Modeling
Authors: Yi Yang , Zhao Yue-Yue , Cao Song-Yin
Published: November 2013

This paper studies the fuzzy modeling problem and the fault detection and diagnosis (FDD) algorithm for non-Gaussian stochastic distribution systems based on the nonlinear fuzzy filter design. Following spline function approximation for output probability density functions (PDFs), the T-S fuzzy model is built as a nonlinear identifier to describe the dynamic relationship between the control input and the weight vector. By combining the designed filter and the threshold value, the fault in T-S weight model can be detected and the stability of error system can also be guaranteed. Moreover, the novel adaptive fuzzy filter based on stochastic distribution function is designed to estimate the size of system fault. Finally, the simulation results can well verify the effectiveness of the proposed algorithm for the constant fault and the time-varying fault, respectively.
Modeling and Flocking Consensus Analysis for Large-Scale UAV Swarms
Authors: Bing Li , Jie Li , KeWei Huang
Published: November 2013

Recently, distributed coordination control of the unmanned aerial vehicle (UAV) swarms has been a particularly active topic in intelligent system field. In this paper, through understanding the emergent mechanism of the complex system, further research on the flocking and the dynamic characteristic of UAV swarms will be given. Firstly, this paper analyzes the current researches and existent problems of UAV swarms. Afterwards, by the theory of stochastic process and supplemented variables, a differential-integral model is established, converting the system model into Volterra integral equation. The existence and uniqueness of the solution of the system are discussed. Then the flocking control law is given based on artificial potential with system consensus. At last, we analyze the stability of the proposed flocking control algorithm based on the Lyapunov approach and prove that the system in a limited time can converge to the consensus direction of the velocity. Simulation results are provided to verify the conclusion.
Development of Antibiotics Impregnated Nanosized Silver Phosphate‐Doped Hydroxyapatite Bone Graft
Authors: Suvannapruk Waraporn , Thammarakcharoen Faungchat , Phanpiriya Phetrung , Suwanprateeb Jintamai
Published: November 2013

Nanosized Ag3PO4 loaded hydroxyapatite which was prepared by a novel low temperature phosphorization of 3D printed calcium sulfate dihydrate at the nominal silver concentration of 0.001 M and 0.005 M was impregnated by two antibiotics including gentamicin and vancomycin. Phase composition, microstructure, antibiotics loading, silver content, antimicrobial performance, and cytotoxic potential of the prepared samples were characterized. It was found that the fabricated sample consisted of hydroxyapatite as a main phase and spherical‐shaped silver phosphate nanoparticles distributing within the cluster of hydroxyapatite crystals. Antibacterial activity of the samples against two bacterial strains (gram negative P. aeruginosa and gram positive S. aureus) was carried out. It was found that the combination of antibiotics and nanosized Ag3PO4 in hydroxyapatite could enhance the antibacterial performance of the samples by increasing the duration in which the materials exhibited antibacterial property and the size of the inhibition zone depending on the type of antibiotics and bacterial strains compared to those contained antibiotics or nanosilver phosphate alone. Cytotoxic potential against osteoblasts of antibiotics impregnated nanosilver phosphate hydroxyapatite was found to depend on the combination of antibiotics content, type of antibiotics, and nanosilver phosphate content.