bluuebunny/crossref_metadata_2025 huggingface dataset:
An experimental study to investigate the micro-stereolithography tools for micro injection molding
Authors: Gheisari Reza , Bártolo Paulo , Goddard Nicholas , Domingos Marco Andre das Neves
Published: May 2017

Purpose

The use of microstereolithography (μSL) parts as micro-injection molding (μIM) tools greatly reduces the time and cost to product and offers unique solutions for complex design issues. However, they present challenges to designers because of their strength, thermal characteristics and shorter lifetimes as compared to other mold materials. The purpose of this study is to use SL to build rapid injection mold tools directly combining micro
features for short-run production.

Design/methodology/approach

In total, three tool inserts were produced. Two different μSL mold inserts were produced and evaluated in terms of different build approaches of micro features. One of the inserts includes micro features built horizontally, while the other one collaborates features built vertically, both having same geometrical dimensions. To evaluate the replication capability of prototype tools, two different thicknesses were set for micro features, that is, 30 and 120 μm. The mold inserts were assembled on a metallic mold frame and tested with polypropylene (PP).

Findings

It was observed that using inappropriate resin to fabricate the mold inserts can lead to inaccurate geometrical dimensions of the tool. Therefore, the material with high glass transition temperature (Tg) and low thermal conductivity is preferred. Also, the results of this research work showed that the processed material and technology play an important role both on part quality and tool life. After investigating the tool failure mechanisms during the injection, it was observed that tool failure occurred mainly because of excessive flexural stresses and ejection forces during the cavity filling and part ejection phases, respectively.

Originality/value

The paper describes the capability of μSL mold inserts for the production of small batches of micro-cantilevers which are used in MEMS relays.
The effect of TQM intention to implement on work performance in Oman’s Ministry of Justice
Authors: Mohammed Moosa , Ahmed Elsadig Musa , Anantharaman R.N.
Published: May 2017

Purpose

This study illustrates the intention to implement total quality management (TQM) applications in Oman’s Ministry of Justice (MOJ). The purpose of this paper is to examine the effect of TQM implementation on the MOJ’s work performance (WP).

Design/methodology/approach

The study modified the TQM efficiency model by including new variables that had been ignored by previous studies. As a result, 320 questionnaires have been collected, and the study employed partial least squares for primary data analysis to test the research model.

Findings

Customer focused performance is an important factor that has a direct relationship with WP. However, the findings guide the explanation that there are other factors of TQM that have a direct effect on WP, and this research is directed at future research to select more profound factors of TQM.

Research limitations/implications

The main limitations of this study is that the analysis of the main study was based on the intention to implement TQM to replace the current management system’s practice at Oman’s MOJ.

Originality/value

This study is considered to be one of the significant studies related to the effect of testing intention to implement TQM on WP of Oman’s MOJ.
Impact of CSR on consumer behavior of Bahraini women in the cosmetics industry
Authors: Shabib Fatema , Ganguli Subhadra
Published: May 2017

Purpose

The purpose of this paper is to investigate the impact of corporate social responsibility (CSR) awareness on the attitudes of Bahraini women consumers in the age group of 18-55 and their buying behavior toward cosmetics products.

Design/methodology/approach

Quantitative method is used for focusing on Bahraini women consumers aged between 18-55 years. Primary data comprising consumer’s buying behavior and attitudes were collected through an online questionnaire and analyzed using software like SPSS and Microsoft Office Excel.

Findings

The empirical findings revealed that Bahraini women are not aware of CSR. This lack of awareness leads to the exclusion of CSR as a factor in their purchase decisions. However, the awareness of CSR can become a reason for avoiding purchase of specific cosmetics when the consumer discovers that the producer has been involved in socially irresponsible business practices. Moreover, Bahraini women do not seek CSR-related information voluntarily from the cosmetics industry.

Research limitations/implications

This research paper is subject to sample size limitations; it focuses on women of a specific age group using cosmetics and is limited to the Kingdom of Bahrain. Survey method was used as the only primary data collection method.

Practical implications

This research provides a clear picture of how consumers behave in the absence of any or very little awareness of CSR. It can benefit cosmetics companies, both existing and new, for adopting future long-term marketing strategies to create public awareness of CSR.

Social implications

This research highlights the importance of raising awareness of CSR in the Kingdom of Bahrain and the possible implications of such activities on consumers’ purchases of cosmetics products.

Originality/value

This paper contributes significantly toward information regarding Bahraini consumers’ lack of awareness of CSR and sheds light on consumers’ behavior toward cosmetics products in the Kingdom of Bahrain.
Wavy Surface Cathode Gas Flow Channel Effects on Transport Processes in a Proton Exchange Membrane Fuel Cell
Authors: Li Shian , Yuan Jinliang , Andersson Martin , Xie Gongnan , Sundén Bengt
Published: May 2017

The flow field design of current collectors is a significant issue, which greatly affects the mass transport processes of reactants/products inside fuel cells. Especially for proton exchange membrane (PEM) fuel cells, an appropriate flow field design is very important due to the water balance problem. In this paper, a wavy surface is employed at the cathode flow channel to improve the oxygen mass transport process. The effects of wavy surface on transport processes are numerically investigated by using a three-dimensional anisotropic model including a water phase change model and a spherical agglomerate model. It is found that the wavy configurations enhance the oxygen transport and decrease the water saturation level. It is concluded that the predicted results and findings provide the guideline for the design and manufacture of fuel cells.
Reliable Estimation of Minimum Embedding Dimension Through Statistical Analysis of Nearest Neighbors
Authors: Chelidze David
Published: May 2017

False nearest neighbors (FNN) is one of the essential methods used in estimating the minimally sufficient embedding dimension in delay-coordinate embedding of deterministic time series. Its use for stochastic and noisy deterministic time series is problematic and erroneously indicates a finite embedding dimension. Various modifications to the original method have been proposed to mitigate this problem, but those are still not reliable for noisy time series. Here, nearest-neighbor statistics are studied for uncorrelated random time series and contrasted with the corresponding deterministic and stochastic statistics. New composite FNN metrics are constructed and their performance is evaluated for deterministic, correlates stochastic, and white random time series. In addition, noise-contaminated deterministic data analysis shows that these composite FNN metrics are robust to noise. All FNN results are also contrasted with surrogate data analysis to show their robustness. The new metrics clearly identify random time series as not having a finite embedding dimension and provide information about the deterministic part of correlated stochastic processes. These metrics can also be used to differentiate between chaotic and random time series.
One-to-One and Three-to-One Internal Resonances in MEMS Shallow Arches
Authors: Ouakad Hassen M. , Sedighi Hamid M. , Younis Mohammad I.
Published: May 2017

The nonlinear modal coupling between the vibration modes of an arch-shaped microstructure is an interesting phenomenon, which may have desirable features for numerous applications, such as vibration-based energy harvesters. This work presents an investigation into the potential nonlinear internal resonances of a microelectromechanical systems (MEMS) arch when excited by static (DC) and dynamic (AC) electric forces. The influences of initial rise and midplane stretching are considered. The cases of one-to-one and three-to-one internal resonances are studied using the method of multiple scales and the direct attack of the partial differential equation of motion. It is shown that for certain initial rises, it is possible to activate a three-to-one internal resonance between the first and third symmetric modes. Also, using an antisymmetric half-electrode actuation, a one-to-one internal resonance between the first symmetric and the second antisymmetric modes is demonstrated. These results can shed light on such interactions that are commonly found on micro and nanostructures, such as carbon nanotubes.
Increase in Leg Stiffness Reduces Joint Work During Backpack Carriage Running at Slow Velocities
Authors: Liew Bernard , Netto Kevin , Morris Susan
Published: May 2017

Optimal tuning of leg stiffness has been associated with better running economy. Running with a load is energetically expensive, which could have a significant impact on athletic performance where backpack carriage is involved. The purpose of this study was to investigate the impact of load magnitude and velocity on leg stiffness. We also explored the relationship between leg stiffness and running joint work. Thirty-one healthy participants ran overground at 3 velocities (3.0, 4.0, 5.0 m·s−1), whilst carrying 3 load magnitudes (0%, 10%, 20% weight). Leg stiffness was derived using the direct kinetic-kinematic method. Joint work data was previously reported in a separate study. Linear models were used to establish relationships between leg stiffness and load magnitude, velocity, and joint work. Our results found that leg stiffness did not increase with load magnitude. Increased leg stiffness was associated with reduced total joint work at 3.0 m·s−1, but not at faster velocities. The association between leg stiffness and joint work at slower velocities could be due to an optimal covariation between skeletal and muscular components of leg stiffness, and limb attack angle. When running at a relatively comfortable velocity, greater leg stiffness may reflect a more energy efficient running pattern.
Combined Protein-Rich Diet With Resistance Exercise Intervention to Counteract Sarcopenia: A Qualitative Study on Drivers and Barriers of Compliance
Authors: Herrema Annemarthe L. , Westerman Marjan J. , van Dongen Ellen J.I. , Kudla Urszula , Veltkamp Martijn
Published: May 2017

Interventions combining protein-rich diets with resistance exercises seem a promising avenue in helping to prevent sarcopenia. However, compliance to health interventions is generally low. The aim of the present study was to provide qualitative insights into the drivers and barriers that older adults experience when trying to comply with a combined dietary and physical exercise intervention. Semi-structured interviews with 18 older adults participating in such an intervention were conducted and analyzed using thematic content analysis. Most frequently reported drivers to comply with the diet were a fit with existing habits, knowledge on the health benefits, and product properties (taste, convenience, package). Drivers for physical exercises were existing habits, social contacts, customized support, and experienced physical improvement. It is suggested that customized support is important to successfully implement exercise-protein interventions amongst older adults, especially regarding participants’ habits, product preferences, and social environment.
The Effects of Self-Observation When Combined With a Skilled Model on the Learning of Gymnastics Skills
Authors: Robertson Rebecca , St. Germain Laura , Ste-Marie Diane M.
Published: May 2017

In this experiment, we examined whether self-observation, via video replay, coupled with the viewing of a skilled model was better for motor skill learning than the use of self-observation alone. Twenty-one female gymnasts participated in a within design experiment in which two gymnastics skills were learned. One skill was practiced in conjunction with the self-observation/skilled model pairing and the other with only self-observation. The experiment unfolded over five sessions in which pre-test, baseline, acquisition, retention, and post-test scores were obtained. Analysis of the physical performance scores revealed a significant Condition ×Session interaction in which it was shown that there were no differences between the intervention conditions at baseline and early in acquisition; but, later in acquisition, those skills practiced with the self-observation/skilled model pairing were executed significantly better than those with only self-observation. Also, an error identification test showed that participants had significantly higher response sensitivity scores for those skills learned with the paired intervention compared to self-observation alone. These results suggest that pairing self-observation with a skilled model is better in a gymnastic setting than self-observation alone.
Effectiveness of Vestibular Rehabilitation Therapy for Treatment of Concussed Adolescents With Persistent Symptoms of Dizziness and Imbalance
Authors: Park Kyoungyoun , Ksiazek Thomas , Olson Bernadette
Published: May 2017

Context: Adolescents who suffer sport concussion typically respond to a prescription of cognitive and physical rest in the acute phases of healing; however, some adolescents do not respond to rest alone. Dizziness, unsteadiness, and imbalance are impairments, which may linger longer than 30 days, leading to a diagnosis of postconcussion syndrome (PCS). Vestibular assessment and therapy may benefit adolescents suffering from these persistent symptoms. Clinical Question: Does vestibular rehabilitation therapy (VRT) rather than continued prescription of rest (cognitive and physical) reduce recovery time and persistent symptoms of dizziness, unsteadiness, and imbalance in adolescents (12–18 y) who suffer PCS following a sports-related concussion? Summary of Key Findings: All 4 studies selected included adolescents suffering from PCS, specifically continued dizziness, unsteadiness, and imbalance. VRT was an effective intervention for this population. Adolescents presenting with this cluster of symptoms may also demonstrate verbal and visual memory loss linked to changes in the vestibular system postconcussion. Improved screening tools can help better understand vestibular system changes, identify adolescents who may benefit from VRT sooner, and decrease long-term impairments. Clinical Bottom Line: Moderate evidence supports that adolescents who suffer from persistent symptoms of dizziness, unsteadiness, and imbalance following sport concussion should be evaluated more specifically and earlier for vestibular dysfunction and can benefit from participation in individualized VRT. Early evaluation and treatment may result in a reduction of time lost from sport as well as a return to their premorbid condition. For these adolescents, VRT may be more beneficial than continued physical and cognitive rest when an adolescent’s symptoms last longer than 30 days. Strength of Recommendation: Grade B evidence exists to support that VRT is more effective than continued cognitive and physical rest in reducing persistent symptoms of dizziness, unsteadiness, and imbalance in adolescents who suffer PCS.
Athlete Burnout Prevention Strategies Used by U.S. Collegiate Soccer Coaches
Authors: Kroshus Emily , DeFreese J.D.
Published: May 2017

Athlete burnout is an important psychological health concern that may be influenced by coach behaviors. Participants were 933 collegiate soccer coaches who described their utilization of burnout prevention strategies. Deductive content analysis was used to categorize and interpret responses. The most frequently endorsed prevention strategies involved managing/limiting physical stressors. Reducing nonsport stressors and promoting autonomy and relatedness were also endorsed. Motivational climate changes and secondary prevention strategies were infrequently reported. These findings can help inform the design of educational programming to ensure that all coaches are aware of the range of ways in which they can help prevent athlete burnout.
Harnessing the hygroscopic and biofluorescent behaviors of genetically tractable microbial cells to design biohybrid wearables
Authors: Wang Wen , Yao Lining , Cheng Chin-Yi , Zhang Teng , Atsumi Hiroshi , Wang Luda , Wang Guanyun , Anilionyte Oksana , Steiner Helene , Ou Jifei , Zhou Kang , Wawrousek Chris , Petrecca Katherine , Belcher Angela M. , Karnik Rohit , Zhao Xuanhe , Wang Daniel I. C. , Ishii Hiroshi
Published: May 2017

We harnessed the hygroscopic and biofluorescent behaviors of microbial cells to design sweat-responsive biohybrid wearables.
Observation and ultrafast dynamics of a nonvalence correlation-bound state of an anion
Authors: Bull James N. , Verlet Jan R. R.
Published: May 2017

A nonvalence electronic state predominantly bound by correlation forces is spectroscopically characterized in a cluster anion.
Exploring a Possible Link between the Intestinal Microbiota and Feed Efficiency in Pigs
Authors: McCormack Ursula M. , Curião Tânia , Buzoianu Stefan G. , Prieto Maria L. , Ryan Tomas , Varley Patrick , Crispie Fiona , Magowan Elizabeth , Metzler-Zebeli Barbara U. , Berry Donagh , O'Sullivan Orla , Cotter Paul D. , Gardiner Gillian E. , Lawlor Peadar G.
Published: May 2017

Feed efficiency (FE) is critical in pig production for both economic and environmental reasons. As the intestinal microbiota plays an important role in energy harvest, it is likely to influence FE. Therefore, our aim was to characterize the intestinal microbiota of pigs ranked as low, medium, and high residual feed intake ([RFI] a metric for FE), where genetic, nutritional, and management effects were minimized, to explore a possible link between the intestinal microbiota and FE. Eighty-one pigs were ranked according to RFI between weaning and day 126 postweaning, and 32 were selected as the extremes in RFI (12 low, 10 medium, and 10 high). Intestinal microbiota diversity, composition, and predicted functionality were assessed by 16S rRNA gene sequencing. Although no differences in microbial diversity were found, some RFI-associated compositional differences were revealed, principally among members of
Firmicutes
, predominantly in feces at slaughter (albeit mainly for low-abundance taxa). In particular, microbes associated with a leaner and healthier host (e.g.,
Christensenellaceae
,
Oscillibacter
, and
Cellulosilyticum
) were enriched in low RFI (more feed-efficient) pigs. Differences were also observed in the ileum of low RFI pigs; most notably,
Nocardiaceae
(
Rhodococcus
) were less abundant. Predictive functional analysis suggested improved metabolic capabilities in these animals, especially within the ileal microbiota. Higher ileal isobutyric acid concentrations were also found in low RFI pigs. Overall, the differences observed within the intestinal microbiota of low RFI pigs compared with that of their high RFI counterparts, albeit relatively subtle, suggest a possible link between the intestinal microbiota and FE in pigs.

IMPORTANCE
This study is one of the first to show that differences in intestinal microbiota composition, albeit subtle, may partly explain improved feed efficiency (FE) in low residual feed intake (RFI) pigs. One of the main findings is that, although microbial diversity did not differ among animals of varying FE, specific intestinal microbes could potentially be linked with porcine FE. However, as the factors impacting FE are still not fully understood, intestinal microbiota composition may not be a major factor determining differences in FE. Nonetheless, this work has provided a potential set of microbial biomarkers for FE in pigs. Although culturability could be a limiting factor and intervention studies are required, these taxa could potentially be targeted in the future to manipulate the intestinal microbiome so as to improve FE in pigs. If successful, this has the potential to reduce both production costs and the environmental impact of pig production.
Postepizootic Persistence of Asymptomatic Mycoplasma conjunctivae Infection in Iberian Ibex
Authors: Fernández-Aguilar Xavier , Cabezón Oscar , Granados José Enrique , Frey Joachim , Serrano Emmanuel , Velarde Roser , Cano-Manuel Francisco Javier , Mentaberre Gregorio , Ráez-Bravo Arián , Fandos Paulino , López-Olvera Jorge Ramón
Published: May 2017

The susceptibility of the Iberian ibex (
Capra pyrenaica
) to
Mycoplasma conjunctivae
ocular infection and the changes in their interaction over time were studied in terms of clinical outcome, molecular detection, and IgG immune response in a captive population that underwent a severe infectious keratoconjunctivitis (IKC) outbreak.
Mycoplasma conjunctivae
was detected in the Iberian ibex, coinciding with the IKC outbreak. Its prevalence had a decreasing trend in 2013 that was consistent with the clinical resolution (August, 35.4%; September, 8.7%; November, 4.3%). Infections without clinical outcome were, however, still detected in the last handling in November. Sequencing and cluster analyses of the
M. conjunctivae
strains found 1 year later in the ibex population confirmed the persistence of the same strain lineage that caused the IKC outbreak but with a high prevalence (75.3%) of mostly asymptomatic infections and with lower DNA load of
M. conjunctivae
in the eyes (mean quantitative PCR [qPCR] cycle threshold [

C
T

], 36.1 versus 20.3 in severe IKC). Significant age-related differences of
M. conjunctivae
prevalence were observed only under IKC epizootic conditions. No substantial effect of systemic IgG on
M. conjunctivae
DNA in the eye was evidenced with a linear mixed-models selection, which indicated that systemic IgG does not necessarily drive the resolution of
M. conjunctivae
infection and does not explain the epidemiological changes observed. The results show how both epidemiological scenarios, i.e., severe IKC outbreak and mostly asymptomatic infections, can consecutively occur by entailing mycoplasma persistence.

IMPORTANCE
Mycoplasma
infections are reported in a wide range of epidemiological scenarios that involve severe disease to asymptomatic infections. This study allows a better understanding of the transition between two different
Mycoplasma conjunctivae
epidemiological scenarios described in wild host populations and highlights the ability of
M. conjunctivae
to adapt, persist, and establish diverse interactions with its hosts. The proportion of asymptomatic and clinical
M. conjunctivae
infections in a host population may not be regarded only in response to intrinsic host species traits (i.e., susceptibility) but also to a specific host-pathogen interaction, which in turn influences the infection dynamics. Both epidemic infectious keratoconjunctivitis and a high prevalence of asymptomatic
M. conjunctivae
infections may occur in the same host population, depending on the circulation of
M. conjunctivae
, its maintenance, and the progression of the host-pathogen interactions.
Impact of Acanthamoeba Cysts on Stress Resistance of Salmonella enterica Serovar Typhimurium, Yersinia enterocolitica 4/O:3, Listeria monocytogenes 1/2a, and Escherichia coli O:26
Authors: Lambrecht Ellen , Baré Julie , Sabbe Koen , Houf Kurt
Published: May 2017

The formation of robust resting cysts enables
Acanthamoeba
to resist harsh environmental conditions. This study investigated to what extent these cysts are resistant to physical and chemical stresses as applied in food industry cleaning and disinfection procedures. Moreover, it was assessed whether certain intracystic meat-borne bacterial pathogens are more stress resistant than free-living bacterial monocultures and if intracystic passage and subsequent association with trophozoites induces cross-tolerance toward other stressors. Several physical and chemical stressors (NaCl, H
2
O
2
, benzalkonium chloride, 55°C, heating until boiling, ethanol, dishwashing detergent, and sodium hypochlorite) frequently used in domestic and industrial food-related environments were tested against (i)
Acanthamoeba castellanii
cysts, (ii) single strains of bacterial monocultures, (iii) intracystic bacteria, and (iv) bacteria after intracystic passage (cyst-primed bacteria). Only heating until boiling and hypochlorite treatment were cysticidal. After boiling, no viable trophozoites could be recovered from the cysts, and hypochlorite treatment caused a 1.34- to 4.72-log
10
cells/ml reduction in cyst viability. All treatments were effective in reducing or even eliminating the tested bacterial monocultures, whereas bacteria residing inside cysts were more tolerant toward these stressors. All cyst-primed bacteria exhibited an increased tolerance toward subsequent H
2
O
2
(>92% decrease in median log
10
CFU/ml reduction) and 70% ethanol (>99% decrease) treatments. Moreover, intracystic passage significantly increased the survival of
Yersinia enterocolitica
(74% decrease in median log
10
reduction),
Escherichia coli
(58%), and
Salmonella enterica
(48%) after NaCl treatment and of
E. coli
(96%),
S. enterica
(99%), and
Listeria monocytogenes
(99%) after sodium hypochlorite treatment compared with that of nonprimed bacteria.

IMPORTANCE
The results from this study demonstrated that both viable and nonviable amoebal cysts can protect internalized bacteria against stressful conditions. Moreover, cyst passage can induce cross-tolerance in bacteria, increasing their survival when exposed to selected stressors. These findings underscore the potential importance of free-living amoebae in food-related environments and their impact on the persistence of meat-borne bacterial pathogens.
Zinc Resistance within Swine-Associated Methicillin-Resistant Staphylococcus aureus Isolates in the United States Is Associated with Multilocus Sequence Type Lineage
Authors: Hau Samantha J. , Frana Timothy , Sun Jisun , Davies Peter R. , Nicholson Tracy L.
Published: May 2017

Zinc resistance in livestock-associated methicillin-resistant
Staphylococcus aureus
(LA-MRSA) sequence type 398 (ST398) is primarily mediated by the
czrC
gene colocated with the
mecA
gene, encoding methicillin resistance, within the type V staphylococcal cassette chromosome
mec
(SCC
mec
) element. Because
czrC
and
mecA
are located within the same mobile genetic element, it has been suggested that the use of zinc in feed as an antidiarrheal agent has the potential to contribute to the emergence and spread of methicillin-resistant
S. aureus
(MRSA) in swine, through increased selection pressure to maintain the SCC
mec
element in isolates obtained from pigs. In this study, we report the prevalence of the
czrC
gene and phenotypic zinc resistance in U.S. swine-associated LA-MRSA ST5 isolates, MRSA ST5 isolates from humans with no swine contact, and U.S. swine-associated LA-MRSA ST398 isolates. We demonstrated that the prevalence of zinc resistance in U.S. swine-associated LA-MRSA ST5 isolates was significantly lower than the prevalence of zinc resistance in MRSA ST5 isolates from humans with no swine contact and swine-associated LA-MRSA ST398 isolates, as well as prevalences from previous reports describing zinc resistance in other LA-MRSA ST398 isolates. Collectively, our data suggest that selection pressure associated with zinc supplementation in feed is unlikely to have played a significant role in the emergence of LA-MRSA ST5 in the U.S. swine population. Additionally, our data indicate that zinc resistance is associated with the multilocus sequence type lineage, suggesting a potential link between the genetic lineage and the carriage of resistance determinants.

IMPORTANCE
Our data suggest that coselection thought to be associated with the use of zinc in feed as an antimicrobial agent is not playing a role in the emergence of livestock-associated methicillin-resistant
Staphylococcus aureus
(LA-MRSA) ST5 in the U.S. swine population. Additionally, our data indicate that zinc resistance is more associated with the multilocus sequence type lineage, suggesting a potential link between the genetic lineage and the carriage of resistance markers. This information is important for public health professionals, veterinarians, producers, and consumers.
Sulfide-Induced Dissimilatory Nitrate Reduction to Ammonium Supports Anaerobic Ammonium Oxidation (Anammox) in an Open-Water Unit Process Wetland
Authors: Jones Zackary L. , Jasper Justin T. , Sedlak David L. , Sharp Jonathan O.
Published: May 2017

Open-water unit process wetlands host a benthic diatomaceous and bacterial assemblage capable of nitrate removal from treated municipal wastewater with unexpected contributions from anammox processes. In exploring mechanistic drivers of anammox, 16S rRNA gene sequencing profiles of the biomat revealed significant microbial community shifts along the flow path and with depth. Notably, there was an increasing abundance of sulfate reducers (
Desulfococcus
and other
Deltaproteobacteria
) and anammox microorganisms (
Brocadiaceae
) with depth. Pore water profiles demonstrated that nitrate and sulfate concentrations exhibited a commensurate decrease with biomat depth accompanied by the accumulation of ammonium. Quantitative PCR targeting the anammox hydrazine synthase gene,
hzsA
, revealed a 3-fold increase in abundance with biomat depth as well as a 2-fold increase in the sulfate reductase gene,
dsrA
. These microbial and geochemical trends were most pronounced in proximity to the influent region of the wetland where the biomat was thickest and influent nitrate concentrations were highest. While direct genetic queries for dissimilatory nitrate reduction to ammonium (DNRA) microorganisms proved unsuccessful, an increasing depth-dependent dominance of
Gammaproteobacteria
and diatoms that have previously been functionally linked to DNRA was observed. To further explore this potential, a series of microcosms containing field-derived biomat material confirmed the ability of the community to produce sulfide and reduce nitrate; however, significant ammonium production was observed only in the presence of hydrogen sulfide. Collectively, these results suggest that biogenic sulfide induces DNRA, which in turn can explain the requisite coproduction of ammonium and nitrite from nitrified effluent necessary to sustain the anammox community.

IMPORTANCE
This study aims to increase understanding of why and how anammox is occurring in an engineered wetland with limited exogenous contributions of ammonium and nitrite. In doing so, the study has implications for how geochemical parameters could potentially be leveraged to impact nutrient cycling and attenuation during the operation of treatment wetlands. The work also contributes to ongoing discussions about biogeochemical signatures surrounding anammox processes and enhances our understanding of the contributions of anammox processes in freshwater environments.
Environmental Spread of New Delhi Metallo-β-Lactamase-1-Producing Multidrug-Resistant Bacteria in Dhaka, Bangladesh
Authors: Islam Mohammad Aminul , Islam Moydul , Hasan Rashedul , Hossain M. Iqbal , Nabi Ashikun , Rahman Mahdia , Goessens Wil H. F. , Endtz Hubert P. , Boehm Alexandria B. , Faruque Shah M.
Published: May 2017

Resistance to carbapenem antibiotics through the production of New Delhi metallo-β-lactamase-1 (NDM-1) constitutes an emerging challenge in the treatment of bacterial infections. To monitor the possible source of the spread of these organisms in Dhaka, Bangladesh, we conducted a comparative analysis of wastewater samples from hospital-adjacent areas (HAR) and from community areas (COM), as well as public tap water samples, for the occurrence and characteristics of NDM-1-producing bacteria. Of 72 HAR samples tested, 51 (71%) samples were positive for NDM-1-producing bacteria, as evidenced by phenotypic tests and the presence of the
bla
NDM-1
gene, compared to 5 of 41 (12.1%) samples from COM samples (
P
< 0.001). All tap water samples were negative for NDM-1-producing bacteria.
Klebsiella pneumoniae
(44%) was the predominant bacterial species among
bla
NDM-1
-positive isolates, followed by
Escherichia coli
(29%),
Acinetobacter
spp. (15%), and
Enterobacter
spp. (9%). These bacteria were also positive for one or more other antibiotic resistance genes, including
bla
CTX-M-1
(80%),
bla
CTX-M-15
(63%),
bla
TEM
(76%),
bla
SHV
(33%),
bla
CMY-2
(16%),
bla
OXA-48-like
(2%),
bla
OXA-1
(53%), and
bla
OXA-47-like
(60%) genes. Around 40% of the isolates contained a
qnr
gene, while 50% had 16S rRNA methylase genes. The majority of isolates hosted multiple plasmids, and plasmids of 30 to 50 MDa carrying
bla
NDM-1
were self-transmissible. Our results highlight a number of issues related to the characteristics and source of spread of multidrug-resistant bacteria as a potential public health threat. In view of the existing practice of discharging untreated liquid waste into the environment, hospitals in Dhaka city contribute to the potential dissemination of NDM-1-producing bacteria into the community.

IMPORTANCE
Infections caused by carbapenemase-producing
Enterobacteriaceae
are extremely difficult to manage due to their marked resistance to a wide range of antibiotics. NDM-1 is the most recently described carbapenemase, and the
bla
NDM-1
gene, which encodes NDM-1, is located on self-transmissible plasmids that also carry a considerable number of other antibiotic resistance genes. The present study shows a high prevalence of NDM-1-producing organisms in the wastewater samples from hospital-adjacent areas as a potential source for the spread of these organisms to community areas in Dhaka, Bangladesh. The study also examines the characteristics of the isolates and their potential to horizontally transmit the resistance determinants. The significance of our research is in identifying the mode of spread of multiple-antibiotic-resistant organisms, which will allow the development of containment measures, leading to broader impacts in reducing their spread to the community.
Genomic Analysis of Calderihabitans maritimus KKC1, a Thermophilic, Hydrogenogenic, Carboxydotrophic Bacterium Isolated from Marine Sediment
Authors: Omae Kimiho , Yoneda Yasuko , Fukuyama Yuto , Yoshida Takashi , Sako Yoshihiko
Published: May 2017

Calderihabitans maritimus
KKC1 is a thermophilic, hydrogenogenic carboxydotroph isolated from a submerged marine caldera. Here, we describe the
de novo
sequencing and feature analysis of the
C. maritimus
KKC1 genome. Genome-based phylogenetic analysis confirmed that
C. maritimus
KKC1 was most closely related to the genus
Moorella
, which includes well-studied acetogenic members. Comparative genomic analysis revealed that, like
Moorella
,
C. maritimus
KKC1 retained both the CO
2
-reducing Wood-Ljungdahl pathway and energy-converting hydrogenase-based module activated by reduced ferredoxin, but it lacked the HydABC and NfnAB electron-bifurcating enzymes and pyruvate:ferredoxin oxidoreductase required for ferredoxin reduction for acetogenic growth. Furthermore,
C. maritimus
KKC1 harbored six genes encoding CooS, a catalytic subunit of the anaerobic CO dehydrogenase that can reduce ferredoxin via CO oxidation, whereas
Moorella
possessed only two CooS genes. Our analysis revealed that three
cooS
genes formed known gene clusters in other microorganisms, i.e.,
cooS
-acetyl coenzyme A (acetyl-CoA) synthase (which contained a frameshift mutation),
cooS
–energy-converting hydrogenase, and
cooF-cooS
-FAD-NAD oxidoreductase, while the other three had novel genomic contexts. Sequence composition analysis indicated that these
cooS
genes likely evolved from a common ancestor. Collectively, these data suggest that
C. maritimus
KKC1 may be highly dependent on CO as a low-potential electron donor to directly reduce ferredoxin and may be more suited to carboxydotrophic growth compared to the acetogenic growth observed in
Moorella
, which show adaptation at a thermodynamic limit.

IMPORTANCE
Calderihabitans maritimus
KKC1 and members of the genus
Moorella
are phylogenetically related but physiologically distinct. The former is a hydrogenogenic carboxydotroph that can grow on carbon monoxide (CO) with H
2
production, whereas the latter include acetogenic bacteria that grow on H
2
plus CO
2
with acetate production. Both species may require reduced ferredoxin as an actual “energy equivalent,” but ferredoxin is a low-potential electron carrier and requires a high-energy substrate as an electron donor for reduction. Comparative genomic analysis revealed that
C. maritimus
KKC1 lacked specific electron-bifurcating enzymes and possessed six CO dehydrogenases, unlike
Moorella
species. This suggests that
C. maritimus
KKC1 may be more dependent on CO, a strong electron donor that can directly reduce ferredoxin via CO dehydrogenase, and may exhibit a survival strategy different from that of acetogenic
Moorella
, which solves the energetic barrier associated with endergonic reduction of ferredoxin with hydrogen.
Understanding and Alleviating the Impact of the Flash Address Translation on Solid State Devices
Authors: Zhou You , Wu Fei , Huang Ping , He Xubin , Xie Changsheng , Zhou Jian
Published: May 2017

Flash-based solid state devices (SSDs) have been widely employed in consumer and enterprise storage systems. However, the increasing SSD capacity imposes great pressure on performing efficient logical to physical address translation in a page-level flash translation layer (FTL). Existing schemes usually employ a built-in RAM to store mapping information, called
mapping cache
, to speed up the address translation. Since only a fraction of the mapping table can be cached due to limited cache space, a large number of extra flash accesses are required for cache management and garbage collection, degrading the performance and lifetime of an SSD. In this paper, we first apply analytical models to investigate the key factors that incur extra flash accesses during address translation. Then, we propose a novel page-level FTL with an efficient translation page-level caching mechanism, named
TPFTL
, to minimize the extra flash accesses. TPFTL employs a two-level least recently used (LRU) list with space-efficient optimizations to organize cached mapping entries. Inspired by the models, we further design a workload-adaptive loading policy combined with an efficient replacement policy to increase the cache hit rate and reduce the writebacks of replaced dirty entries. Finally, we evaluate TPFTL using extensive trace-driven simulations. Our evaluation results show that compared to the state-of-the-art FTLs, TPFTL significantly reduces the extra operations caused by address translation, achieving reductions on system response time and write amplification by up to 27.1% and 32.2%, respectively.
Automated Integration of Dual-Edge Clocking for Low-Power Operation in Nanometer Nodes
Authors: Bonetti Andrea , Preyss Nicholas , Teman Adam , Burg Andreas
Published: May 2017

Clocking power, including both clock distribution and registers, has long been one of the primary factors in the total power consumption of many digital systems. One straightforward approach to reduce this power consumption is to apply dual-edge-triggered (DET) clocking, as sequential elements operate at half the clock frequency while maintaining the same throughput as with conventional single-edge-triggered (SET) clocking. However, the DET approach is rarely taken in modern integrated circuits, primarily due to the perceived complexity of integrating such a clocking scheme. In this article, we first identify the most promising conditions for achieving low-power operation with DET clocking and then introduce a fully automated design flow for applying DET to a conventional SET design. The proposed design flow is demonstrated on three benchmark circuits in a 40nm CMOS technology, providing as much as a 50% reduction in clock distribution and register power consumption.
Optical Overlay NUCA
Authors: Peter Eldhose , Arora Anuj , Bashir Janibul , Bagaria Akriti , Sarangi Smruti R.
Published: May 2017

In this article, we propose using optical networks-on-chip (NoCs) to design cache access protocols for large shared L2 caches. We observe that the problem is unique because optical networks have very low latency, and in principle all of the cache banks are very close to each other. A naive approach is to broadcast a request to a set of banks that might possibly contain the copy of a block. However, this approach is wasteful in terms of energy and bandwidth. Hence, we propose a set of novel schemes that create a set of virtual networks (
overlays
) of cache banks over a physical optical NoC. We search for a block inside each overlay using a combination of multicast and unicast messages. We first propose two simple protocols:
TSI
and
Broadcast
. The former uses unicast messages, and the latter uses multicast messages. We subsequently propose an improved scheme,
OP_BCAST
, that combines the best of
TSI
and
Broadcast
, and mainly uses restricted multicast messages. Then we propose a set of novel hardware structures for creating and managing overlays, for efficiently locating blocks in the overlay, and for implementing dynamically changing overlays with
OP_BCAST
. The performance of the
TSI
scheme is within 2% to 3% of a broadcast scheme, and it is faster than traditional schemes with electrical networks by 26%. Compared to the broadcast scheme, it reduces the number of accesses, and consequently the dynamic energy of the caches by 6% to 8%.
OP_BCAST
is 34% faster than the best solutions with copper-based NoCs; moreover, it reduces the dynamic energy for cache access by 33% compared to the
TSI
scheme.
FFA2 activation combined with ulcerogenic COX inhibition induces duodenal mucosal injury via the 5-HT pathway in rats
Authors: Akiba Yasutada , Maruta Koji , Narimatsu Kazuyuki , Said Hyder , Kaji Izumi , Kuri Ayaka , Iwamoto Ken-ichi , Kuwahara Atsukazu , Kaunitz Jonathan D.
Published: May 2017

Serotonin (5-HT), predominantly synthesized and released by enterochromaffin cells, is implicated in gastrointestinal symptoms such as emesis, abdominal pain, and diarrhea. Because luminal short-chain fatty acids (SCFAs) release 5-HT from enterochromaffin cells, which express the SCFA receptor free fatty acid receptor 2 (FFA2) in rat duodenum, we examined the effects of the selective FFA2 agonist phenylacetamide-1 (PA1) on duodenal 5-HT release with consequent bicarbonate secretion [duodenal bicarbonate secretion (DBS)] and on indomethacin (IND)-induced enteropathy. Intestinal injury was induced by IND (10 mg/kg sc) with or without PA1. We measured DBS in vivo in a duodenal loop perfused with PA1 while measuring 5-HT released in the portal vein. Duodenal blood flow was measured by laser-Doppler flowmetry. IND induced small intestinal ulcers with duodenal sparing. PA1 given with IND (IND + PA1) dose dependently induced duodenal erosions. IND + PA1-induced duodenal lesions were inhibited by the FFA2 antagonist GLPG-0974, ondansetron, or omeprazole but not by RS-23597 or atropine. Luminal perfusion of PA1 augmented DBS accompanied by increased portal blood 5-HT concentrations with approximately eight times more release at 0.1 mM than at 1 µM, with the effects inhibited by coperfusion of GLPG-0974. Luminal PA1 at 1 µM increased, but at 0.1 mM diminished, duodenal blood flow. Cosuperfusion of PA1 (0.1 mM) decreased acid-induced hyperemia, further reduced by IND pretreatment but restored by ondansetron. These results suggest that, although FFA2 activation enhances duodenal mucosal defenses, FFA2 overactivation during ulcerogenic cyclooxygenase inhibition may increase the vulnerability of the duodenal mucosa to gastric acid via excessive 5-HT release and 5-HT3receptor activation, implicated in foregut-related symptoms such as emesis and epigastralgia.

NEW & NOTEWORTHY Luminal free fatty acid receptor 2 agonists stimulate enterochromaffin cells and release serotonin, which enhances mucosal defenses in rat duodenum. However, overdriving serotonin release with high luminal concentrations of free fatty acid 2 ligands such as short-chain fatty acids injures the mucosa by decreasing mucosal blood flow. These results are likely implicated in serotonin-related dyspeptic symptom generation because of small intestinal bacterial overgrowth, which is hypothesized to generate excess SCFAs in the foregut, overdriving serotonin release from enterochromaffin cells.
Emerging concepts in biliary repair and fibrosis
Authors: Fabris Luca , Spirli Carlo , Cadamuro Massimiliano , Fiorotto Romina , Strazzabosco Mario
Published: May 2017

Chronic diseases of the biliary tree (cholangiopathies) represent one of the major unmet needs in clinical hepatology and a significant knowledge gap in liver pathophysiology. The common theme in cholangiopathies is that the target of the disease is the biliary tree. After damage to the biliary epithelium, inflammatory changes stimulate a reparative response with proliferation of cholangiocytes and restoration of the biliary architecture, owing to the reactivation of a variety of morphogenetic signals. Chronic damage and inflammation will ultimately result in pathological repair with generation of biliary fibrosis and clinical progression of the disease. The hallmark of pathological biliary repair is the appearance of reactive ductular cells, a population of cholangiocyte-like epithelial cells of unclear and likely mixed origin that are able to orchestrate a complex process that involves a number of different cell types, under joint control of inflammatory and morphogenetic signals. Several questions remain open concerning the histogenesis of reactive ductular cells, their role in liver repair, their mechanism of activation, and the signals exchanged with the other cellular elements cooperating in the reparative process. This review contributes to the current debate by highlighting a number of new concepts derived from the study of the pathophysiology of chronic cholangiopathies, such as congenital hepatic fibrosis, biliary atresia, and Alagille syndrome.