bluuebunny/crossref_metadata_2025 huggingface dataset:
OPTIMIZATION OF CHIPOTLE PEPPER SMOKING PROCESS USING RESPONSE SURFACE METHODOLOGY*
Authors: GÓMEZ‐MORIEL CINTHIA B. , QUINTERO‐RAMOS ARMANDO , CAMACHO‐DÁVILA ALEJANDRO , RUIZ‐GUTIÉRREZ MARTHA G. , TALAMÁS‐ABBUD RICARDO , OLIVAS‐VARGAS RAMÓN , BARNARD JOHN
Published: December 2011

Effects of smoking time and temperature on optimal chipotle pepper production were evaluated and optimized using the response surface methodology. Batches of red jalapeño peppers were smoked under different temperatures (65.8, 70, 80, 90, 94.1C) and times (0.96, 2, 4.5, 7, 8 h). Afterward, samples were evaluated for moisture, rheological properties and total phenols. Samples were then dried from 80C to between 0.123 and 0.204 kg H2O/kg dry matter and evaluated for rheological properties, texture, rehydration, color and phenols. Phenol content, rehydration ratio, firmness of peppers, and rheological properties and color of puree were affected (P < 0.05) by both temperature and time. Best smoking conditions used temperatures of 74–79C, and times between 8.0 and 7.4 h resulting in viscosities of 5.1–6.5 Pa·s with phenol content of 110–120 mg/kg, rehydration ratios of 3.7–4.1, firmness of 1.27–1.49 N and acceptable color. Smoking time was significantly reduced and quality maintained.

PRACTICAL APPLICATIONS

Chipotle pepper is highly appreciated by consumers because of their aroma and flavor characteristics. Chipotle pepper is obtained by smoking red jalapeño in open ovens, where combustion gases from hardwoods are passed during long times to smoke and dehydrate them. This process has the disadvantage of producing environmental contamination and wide quality variability because of a poor process control. In this study, a correlation of smoking and drying was optimized in order to determine the effect of temperature and smoking time on the physical and chemical characteristics of the chipotle pepper. Additionally, polynomial models are presented for each variable evaluated in the smoking chipotle pepper operation and optimized for the desired quality of the chipotle pepper. This information can be useful to processors because they can achieve a ninefold reduction in the smoking time compared with the traditional smoking processes without affecting the chemical and physical characteristics of chipotle peppers.
Application of appropriate use criteria for stress myocardial perfusion imaging at two academic medical centers: Compliance and association with image findings
Authors: Soine Laurie A. , Cunningham Susanna L. , Motzer Sandra A. , Inoue Lurdes Y.T. , Caldwell James H.
Published: December 2011

Abstract  Purpose: Explore the extent to which stress myocardial perfusion imaging (MPI) studies for coronary heart disease detection met published appropriate use criteria (AUC), and the association between AUC classification and image findings.

Data sources: Retrospective, descriptive review of stress studies performed at the University of Washington Medical Center (UWMC n= 1377) and the Veterans Health Administration of Puget Sound (VA n= 1445) in the 31 months following AUC publication.

Conclusions: At UWMC and VA, 69% and 89% of MPI studies, respectively, were classified as appropriate, 16% and 3% as inappropriate, and 15% and 8% as uncertain. All differences were significant, p < .001. At UWMC, 11% of appropriate studies and 10% of inappropriate or uncertain studies were abnormal (demonstrating myocardial ischemia or myocardial infarction), p= .93; these analyses were not performed on VA studies.

Implications for practice: Most studies at both sites were classified as appropriate. At UWMC, the likelihood of a study classified as appropriate demonstrating an abnormality was not significantly different from a study classified as uncertain or inappropriate. AUC are imperfect tools but are increasingly created and referenced; as such, it is vital that practicing nurse practitioners are knowledgeable about their creation, application, and evaluation.
Computational Design of Peptide Inhibitor Based on Modifications of Proregion from Plutella xylostella Midgut Trypsin
Authors: Jitonnom Jitrayut , Lomthaisong Khemika , Lee Vannajan S.
Published: December 2011

Many proteases are produced as zymogens bearing the N‐terminal proregions acting both as intramolecular chaperones and as protease inhibitors. The latter role of the proregions as potent and specific inhibitors of their associated protease has been demonstrated in various peptidases and therefore has been targeted for alternative pest control. Here, we isolated amino acid sequence of Plutella xylostella midgut trypsin from the larvae of diamondback moth and tested in silico for its inhibitory activity toward propeptide models using computational modeling and docking. The propeptide models (AAAPGHR, AAAPGRR, AAAPGKR, AAPGHRI, APGHRIV, PGHRIVG, AAAAPGH, and AAAAAPG) were designed based on histidine‐mutated and frame‐shifted modifications of the 7‐amino‐acid proregion (AAAPGHR) of the Plutella xylostella trypsin. Among the eight peptides, AAAPGRR was found to give the best docking scores, showing a strong binding to the cognate enzyme. In addition, the obtained structure of trypsin–AAAPGRR complex was found to share a similar binding mode with a crystal structure of plant protease inhibitor complex. Our results may guide the experiment for the design of future peptide inhibitor with specificity and selectivity for the target enzyme.
RNAi‐based functional genomics in Tribolium castaneum and possible application for controlling insect pests
Authors: NOH Mi Young , BEEMAN Richard W. , ARAKANE Yasuyuki
Published: December 2011

RNA interference or RNAi has been observed in eukaryotes and plays a critical role not only in messenger RNA degradation but also in fine‐tuning of gene activation, transcription and translation. In insects, double‐stranded RNA (dsRNA)‐mediated gene silencing is a simple and powerful reverse genetics tool for analyzing gene functions in both model and non‐model organisms. The red flour beetle, Tribolium castaneum, is an excellent genetic model for pest insect species. Since the completion of the genome sequence of T. castaneum, numerous studies of gene function have been reported. Here we review recent RNAi‐based functional genomics research and systemic RNAi in T. castaneum, and we discuss potential applications of RNAi technology to pest insect control.
Lineages differentiation and population structure of the light‐vented bulbul Pycnonotus sinensis in China based on mitochondrial DNA and microsatellite analysis
Authors: WU Yuchun , LI Hui , ZOU Fasheng , HSU Yucheng
Published: December 2011

The light‐vented bulbul Pycnonotus sinensis is a small resident passerine that is found widely in central and south China, North Vietnam, and some East Asian islands, including Hainan, Taiwan and the Ryukyu Islands. Its subspecies status has been under considerable debate. A total of 10 subspecies have been proposed, but only 4 are widely recognized, including 1 continental taxon, P. s. sinensis, and 3 insular subspecies: P. s. hainanus, P. s. formosae and P. s. orii. Two mitochondrial DNA genes and 9 microsatellite loci were used to investigate the genetic divergence of this species, to identify the evolutionary status of 2 insular subspecies (P. s. hainanus and P. s. formosae) and to uncover probable historical causes that shaped them. The results reveal that P. s. formosae has diverged significantly from the other 2 subspecies because of a substantial time of isolation for populations on Taiwan Island. There was no significant genetic differentiation between P. s. sinensis and P. s. hainanus. The notable morphological difference in P. s. hainanus might be attributed to a rapid, recent adaptation to the tropical environment of Hainan Island. The low genetic divergence between P. s. sinensis and P. s. hainanus might result from a recent divergence or gene flow between them. Two insular subspecies of light‐vented bulbul populations might have diverged recently from their continental relatives through a complex evolution history owing to island isolation, ecological isolation, and possibly even hybridization. Both P. s. hainanus and P. s. formosae should be considered important conservation units because of their morphological and genetic distinctiveness.
Guild composition and habitat use of voles in 2 forest landscapes in south‐eastern Norway
Authors: GORINI Lucrezia , LINNELL John D. C. , BOITANI Luigi , HAUPTMANN Ulrike , ODDEN Morten , WEGGE Per , NILSEN Erlend B.
Published: December 2011

It is widely believed that intensive forestry has influenced small mammal population dynamics, and thereby the entire mammalian community in Fennoscandian boreal forests. The nature of these impacts on the different species is subject to debate. We live‐trapped voles between 2006 and 2009 in 2 commercially harvested forests in south‐eastern Norway. We investigated the variation in vole abundance among habitat types (e.g. mature forest and clear‐cut) and the hypothesis that graminivorous species such as field voles (Microtus agrestis L.) benefit from clear‐cuts at the expense of forest dwellers (i.e. the bank vole, Myodes glareolus Schreb.), using fine‐scale descriptors of the ground vegetation. We could not find support for the hypothesis that field voles show a preference for clear‐cuts, and their overall abundance was low, while bank voles were the dominant species in all habitat types, including clear‐cuts in the peak and pre‐peak years. We found a positive association between bank vole abundance and bilberry (Vaccinium myrtillus L.) availability rather than a specific habitat type. Low field vole density in clear‐cuts might be due to variation in local productivity and ground vegetation as well as to large variation in the species temporal dynamics. The latter is particularly associated with the widespread decline of field voles in Scandinavia. Logging has the potential to negatively affect bank vole population dynamics because of the negative effect on bilberry development.
Vole preference of bilberry along gradients of simulated moose density and site productivity
Authors: PEDERSEN Simen , ANDREASSEN Harry P. , PERSSON Inga‐Lill , JULKUNEN‐TIITTO Riitta , DANELL Kjell , SKARPE Christina
Published: December 2011

Browsing by large herbivores might either increase or decrease preference for the plant by other herbivores, depending on the plant response. Using a cafeteria test, we studied the preference by root voles (Microtus oeconomus [Pallas, 1776]) for bilberry (Vaccinium myrtillus L.) previously subjected to 4 levels of simulated moose (Alces alces [Linnaeus, 1758]) density. The different levels of moose density were simulated at population densities relevant for Fennoscandian conditions, in exclosures situated along a site productivity gradient. We expected: (i) voles to prefer bilberry from high productivity sites over low productivity sites; (ii) voles to prefer browsed bilberry, if plants allocate resources to compensatory growth or to avoid browsed bilberry if plants allocate resources to defense; (iii) these effects to increase with increasing simulated moose density; and (iv) the concentration of plant chemicals and the plant morphology to explain vole preference. Specifically, we predicted that voles would prefer: (i) plants with high nitrogen content; (ii) plants with low content of defensive substances; and (iii) tall plants with long shoots. Voles preferred bilberry from the high productivity sites compared to the low productivity sites. We also found an interaction between site productivity and simulated moose density, where voles preferred unbrowsed plants at low productivity sites and intermediate levels of browsing at high productivity sites. There was no effect of plant chemistry or morphology on vole preference. We conclude that moose browsing impacts the food preference of voles. With the current high densities of moose in Fennoscandia, this could potentially influence vole food selection and population dynamics over large geographical areas.
Behavioral and physiological responses of striped field mice (Apodemus agrarius) to predator odor
Authors: WANG Zhenlong , WANG Baishi , LU Jiqi
Published: December 2011

Predation risk is one of the most important selective forces in nature and has significant effects on the behavior and physiology of prey individuals. Prey species have evolved several different traits to reduce and avoid this predation pressure. This research aimed to determine the behavioral and physiological responses of striped field mice to predator risk. In the present study, we compared the agonistic behavior in male and female striped field mice (Apodemus agrarius Pallas, 1771) of the same sexes under the odor derived from a male Himalayan weasel (Mustela sibirica). Dyads were subjected to 5 min staged encounters in neutral arenas once a week for 3 weeks during which agonistic and social behaviors were recorded and fecal hormone concentrations were determined using pre‐column derivatization and high performance liquid chromatography methods. Furthermore, we also tested the effects of weasel odor on the adrenal glands. The results showed that: (i) male striped field mice did not exhibit any change in body weight and physiological characteristics but their aggressive behavior changed over time, and (ii) females responded to predation risk by significantly decreasing body mass and through increases in fecal cortisol levels and adrenal gland indices. These data show significant sex differences in the body weight, adrenal gland indices and fecal cortisol levels of striped field mouse under predation risk.
Reproductive biology of an old endemic murid rodent of Australia, the Spinifex hopping mouse, Notomys alexis: adaptations for life in the arid zone
Authors: BREED William G. , LEIGH Chris M.
Published: December 2011

The Spinifex hopping mouse (Notomys alexis Thomas, 1922) is an arid adapted Australo–Papuan old endemic rodent that undergoes boom and bust population cycles. In this communication, we review our findings on the timing of reproduction and the potential reproductive rate of this species. To investigate the first question, the reproductive condition of adult females, and occurrence of immatures, in a population on a cattle station in central Australia was determined and, for the second, data from a laboratory colony compared to those previously published on closely related species in other environments. The findings show that, at least in the population at the times that monitoring was performed, reproductive activity was only taking place in spring and early summer, whereas the laboratory study indicates that females have a similar gestation length and litter size to those of most close relatives occurring in other environments. Males have extremely small testes and store relatively few sperm. The findings suggest that Notomys alexis might show some seasonality of reproduction at least in this region of central Australia and that this species does not have a higher reproductive rate than that of related species in other, more predictable, environments.
Proportion and characteristics of transient nodules in a retrospective analysis of pulmonary nodules
Authors: Yu Jin‐Yeong , Lee Boram , Ju Sunmi , Kim Eun‐Young , Kim Yoon‐Hee , Chi Su‐Young , Ban Hee‐Jung , Kwon Yong‐Soo , Oh In‐Jae , Kim Kyu‐Sik , Kim Yu‐Il , Lim Sung‐Chul , Choi Song , Kim Yun‐Hyeon , Kim Young‐Chul
Published: December 2011

Background:  Pulmonary nodules manifest as pure or mixed ground glass opacities (GGOs), or solid nodules.

Methods:  We retrospectively surveyed 317 cases with pulmonary nodules to observe the proportion and predictive factors of transient lesions in patients with pulmonary nodules.

Results:  At the initial computed tomography scan, 63.7% showed solid nodules, while 20.2% had mixed GGOs and 16.1% of cases manifested as pure GGOs. Nodules from 114 cases (36%) disappeared or decreased in size during follow up, while in 203 cases (64%), they did not change or became enlarged. During follow up, more than half of the GGOs resolved (66.7% in pure GGOs, 54.7% in mixed GGOs), while only 22.3% of solid nodules resolved. Between transient and persistent pulmonary nodules, significant differences were observed in age, gender, smoking history, presence of eosinophilia, size, and radiologic attenuation of nodules (solid or GGO). In multivariate analysis, age (≤55 years), size of nodules (>15 mm), eosinophilia, and GGO were significant independent predictors of transient nodules. The main causes of transient nodules were pneumonia or eosinophilic pulmonary infiltrates.

Conclusion:  Thirty‐six percent of pulmonary nodules resolved spontaneously or with medical treatment. Transient nodules showed different clinical and radiological characteristics from persistent nodules.
Efficacy of splenectomy in preventing anemia in patients with recurrent hepatitis C following liver transplantation is not dependent on inosine triphosphate pyrophosphatase genotype
Authors: Motomura Takashi , Koga Erina , Taketomi Akinobu , Fukuhara Takasuke , Mano Yohei , Muto Jun , Konishi Hideyuki , Toshima Takeo , Uchiyama Hideaki , Yoshizumi Tomoharu , Shirabe Ken , Maehara Yoshihiko
Published: December 2011

Aim:  A genetic polymorphism of inosine triphosphate pyrophosphatase (ITPA) has been associated with pegylated‐interferon/ribavirin (PEG‐IFN/RBV)‐induced anemia in chronic hepatitis C patients. However, correlation of the genetic variant with anemia following liver transplantation has not been determined.

Methods:  Sixty‐three hepatitis C virus (HCV)‐positive patients who underwent liver transplantation and PEG‐IFN/RBV therapy were enrolled. The rs1127354 was determined for each individual.

Results:  There was no relationship with anemia or RBV dosage in patients carrying the CC allele (CC group, n = 43) and those carrying the CA allele (CA group, n = 20). The incidence of hemoglobin (Hb) decline >3 g/dL (CC: 4.7%, CA: 0%) was relatively low, whereas the incidence of Hb levels <10 g/dL (CC: 18.6%, CA: 30.0%) was high. Univariate analysis revealed that splenectomy inversely correlated with Hb levels <10 g/dL at 4 weeks (P = 0.04). Among the 22 patients who did not undergo splenectomy, the incidence of Hb levels <10 g/dL tended to be lower in the seven patients carrying the CA allele (28.6%) than in the 15 patients with the CC allele (60.0%).

Conclusion:  The ITPA genetic polymorphism does not correlate with post‐transplant PEG‐IFN/RBV‐induced anemia. Splenectomy is useful in preventing anemia regardless of the ITPA genotype.
Differential conditions for early after‐depolarizations and triggered activity in cardiomyocytes derived from transgenic LQT1 and LQT2 rabbits
Authors: Liu Gong‐Xin , Choi Bum‐Rak , Ziv Ohad , Li Weiyan , de Lange Enno , Qu Zhilin , Koren Gideon
Published: December 2011

Non‐technical summary  Long QT syndrome (LQTS) is a genetic disorder characterized by recurrent syncope and sudden cardiac death (SCD). Type 1 (LQT1) and Type 2 (LQT2) LQTS account for 90% of the genotyped mutations in patients with this disorder. These syndromes have been associated with different sympathetic modes for initiation of cardiac arrest. Using isolated cardiomyocytes and Langendorff‐perfused hearts from transgenic rabbit models of LQT1 and LQT2, we have identified differential conditions and cellular mechanisms for the generation of early afterdepolarizations (EADs), abnormal depolarizations during the plateau and repolarization phase of action potentials and the hallmark of the arrhythmias in LQTS. These differences explain why different types of increased autonomic nervous system activity, i.e. sympathetic surge vs. high sympathetic tone, are associated with the initiation of polymorphic ventricular tachycardia in LQTS patients with different genetic background.
A self‐limiting regulation of vasoconstrictor‐activated TRPC3/C6/C7 channels coupled to PI(4,5)P2‐diacylglycerol signalling
Authors: Imai Yuko , Itsuki Kyohei , Okamura Yasushi , Inoue Ryuji , Mori Masayuki X.
Published: December 2011

Key points 

From brain to digestive tract, electro‐chemical signals are broadly utilized to control the activity of the organs; however, the formation of such signals is very varied in each cell and still unknown in many cells.

In this study, we found a novel mechanism for forming an electrical signal, produced by channels of the transient receptor potential canonical (TRPC) family of channels, which allow the permeation of ions such as sodium and calcium and are opened by the actions of hormones such as adrenaline and noradrenaline.

Such hormones can activate an enzyme (phospholipase C) by which PI(4,5)P2, a member of the membrane lipid ‘phosphoinositide’, is degraded: the degradation of PI(4,5)P2 to produce an agonist (diacylglycerol) involved in the opening of TRPC channels, while the degradation itself is surprisingly critical to the closing of these channels.

As a result of such a self‐limiting effect via membrane lipid degradation, TRPC channels can produce a unique electro‐chemical signal which is tightly bound to the arrangement of membrane lipid and hormones.

Differential sensitivity for PIP2 of TRPC
Fracture Toughness of HSLA Coiled Tubing Used in Oil Wells Operations
Authors: Wainstein J. , Perez Ipiña J.
Published: December 2011

Coiled Tubings are thin walled steel tubes of 25–89 mm diameter and thousands meters long, used in the oil industry for production and maintenance services. They suffer plastic deformation during unwinding of the reel, passing through a goosneck arch guide and an injector unit. Strain levels are of 2–3%, making the tubing fail by low cycle fatigue in around 100 wrap–unwrap cycles. As coiled tubing material generally behaves in a ductile manner at surface and down well temperatures, the R curve has to be known to make instability analyses. J-R curves were determined to characterize the fracture toughness of nonused coiled tubing, using nonstandard specimens due to difficulties with their small thickness and diameters. Different crack lengths and crack locations were tested to analyze the 2C0/W ratio and the influence of the longitudinal weld. The R curves obtained show crack arc length dependence and are influenced by the position of the longitudinal weld.
Multiple Fatigue Crack Growth Prediction Using Stress Intensity Factor Solutions Modified by Empirical Interaction Factors
Authors: Konosu Shinji , Kasahara Kyosuke
Published: December 2011

It is generally believed that multiple fatigue crack growth prediction is difficult with the use of conventional stress intensity factor (SIF) solution calculations because of issues such as SIF magnification and shielding effects. Therefore, almost all the existing Fitness for Service (FFS) rules such as the ASME Code Section XI and JSME Code adopt the procedure whereby multiple cracks grow independently after applying a certain alignment rule based on the initial crack configuration and are combined immediately into an enveloping crack when the crack tips touch. In some cases, the results of the procedures in the existing FFS rules are less accurate in predictions of the service life of cracked components. Therefore, there is still room for improvement, although the procedures are simple for utilities. This paper describes a new approach to predict fatigue crack growth life of multiple nonaligned cracks by the use of SIF solutions modified by empirical interaction factors. Several examples of two nonaligned cracks illustrate the accuracy and effectiveness of the procedure by comparison with numerical analysis by the body force method for two-dimensional problems and with the experimental results given in the literature for three-dimensional problems.
Moving Beyond Nondestructive Examination to Proactive Management of Materials Degradation
Authors: Bond Leonard J.
Published: December 2011

There is growing interest in life extensions to enable longer term operation (LTO) for both existing nuclear power plants (NPPs) and proposed new NPPs. In order to justify an initial license extension for the 40–60 yr period, new nondestructive examination (NDE) approaches have been developed and deployed by NPP operators in their aging management programs. However, to achieve the goals of even longer term operation, and specifically for the United States in looking at methodologies to support subsequent license renewal periods (i.e., 60–80 yr and beyond), it is necessary to understand the capabilities of current NDE methods to detect, monitor, and trend degradation and hence enable timely implementation of appropriate mitigation and corrective actions. This paper discusses insights from past experience, the state-of-the-art, and current activities in the move toward providing a capacity for proactive management of materials degradation to support NPP LTO.
Large Eddy Simulation Investigation of the Hysteresis Effects in the Flow Around an Oscillating Ground Vehicle
Authors: Krajnović Siniša , Bengtsson Anders , Basara Branislav
Published: December 2011

This paper presents large eddy simulations (LES) of flow around a simplified vehicle model oscillating around its vertical axis. The frequency of the Strouhal number St = 0.068 and a relatively small amplitude of the oscillation are chosen to be representative for the crosswind conditions of vehicles on the road. The results were found to agree well with data from previous experimental investigations. Furthermore, the differences in LES flows between quasi-steady and dynamic flow conditions are presented and underlying flow mechanisms are explored. The cause of the phenomena of hysteresis and phase shift was found in the inertia of the flow to adjust to sudden changes in the direction of the oscillation of the body.
Pharmacokinetics of Lamivudine and Lamivudine-Triphosphate after Administration of 300 Milligrams and 150 Milligrams Once Daily to Healthy Volunteers: Results of the ENCORE 2 Study
Authors: Else Laura J. , Jackson Akil , Puls Rebekah , Hill Andrew , Fahey Paul , Lin Enmoore , Amara Alieu , Siccardi Marco , Watson Victoria , Tjia John , Emery Sean , Khoo Saye , Back David J. , Boffito Marta
Published: December 2011

There is interest in evaluating the efficacy of lower doses of certain antiretrovirals for clinical care. We determined here the bioequivalence of plasma lamivudine (3TC) and intracellular 3TC-triphosphate (3TC-TP) concentrations after the administration of two different doses. ENCORE 2 was a randomized crossover study. Subjects received 3TC at 300 and 150 mg once daily for 10 days (arm 1;n= 13) or vice versa (arm 2;n= 11), separated by a 10-day washout. Pharmacokinetic (PK) profiles (0 to 24 h) were assessed on days 10 and 30. Plasma 3TC and 3TC-TP levels in peripheral blood mononuclear cells were quantified by high-performance liquid chromatography-tandem mass spectrometry. Within-subject changes in PK parameters (the area under the concentration-time curve from 0 to 24 h [AUC0-24], the trough concentration of drug in plasma at 24 h [C24], and the maximum concentration of drug in plasma [Cmax]) were evaluated by determining the geometric mean ratios (GMRs) adjusted for study arm, period, and intra-individual variation. Regimens were considered bioequivalent if the 90% confidence interval (90% CI) fell within the range of 0.8 to 1.25. A total of 24 subjects completed the study. The GM (90% CI) 3TC AUC0-24), expressed as ng·h/ml, for the 300- and 150-mg doses were 8,354 (7,609 to 9,172) and 4,773 (4,408 to 5,169), respectively. Bioequivalence in 3TC PK following the administration of 300 and 150 mg was not demonstrated: the GMRs for AUC0-24,C24, andCmaxwere 0.57 (0.55 to 0.60), 0.63 (0.59 to 0.67), and 0.56 (0.53 to 0.60), respectively. The GM (90% CI) 3TC-TP AUC0-24values (pmol·h/106cells) for the 300- and 150-mg doses were 59.5 (51.8 to 68.3) and 44.0 (38.0 to 51.0), respectively. Bioequivalence in 3TC-TP PK following the administration of 300 and 150 mg was not demonstrated: the GMRs for AUC0-24,C24, andCmaxwere 0.73 (0.64 to 0.83), 0.82 (0.68 to 0.99), and 0.70 (0.61 to 0.82), respectively. We found that 3TC at 150 mg is not bioequivalent to the standard regimen of 300 mg, indicating that saturation of cytosine phosphorylation pathways is not achieved at a dose of 150 mg.
Activity of Pyocin S2 against Pseudomonas aeruginosa Biofilms
Authors: Smith Karen , Martin Laura , Rinaldi Angela , Rajendran Ranjith , Ramage Gordon , Walker Daniel
Published: December 2011

In cystic fibrosis patients, chronic lung infection with
Pseudomonas aeruginosa
and the associated decline in lung function are the major cause of mortality. In this report, we show that pyocin S2 displays potent activity against
P. aeruginosa
biofilms, thus representing a potentially improved therapeutic option. Using an invertebrate model of
P. aeruginosa
infection, we also show that pyocin S2 is highly active
in vivo
.
Oritavancin Activity against Vancomycin-Susceptible and Vancomycin-Resistant Enterococci with Molecularly Characterized Glycopeptide Resistance Genes Recovered from Bacteremic Patients, 2009-2010
Authors: Mendes Rodrigo E. , Woosley Leah N. , Farrell David J. , Sader Helio S. , Jones Ronald N.
Published: December 2011

Oritavancin exhibited potent activity against vancomycin-susceptible (MIC
50
and MIC
90
, 0.015/0.03 μg/ml) and
vanB
-carrying
E. faecalis
isolates (MIC
50
and MIC
90
, 0.015 and 0.015 μg/ml). Higher (16- to 32-fold) MIC
50
s and MIC
90
s for
vanA
-harboring
E. faecalis
were noted (MIC
50
and MIC
90
, 0.25 and 0.5 μg/ml), although oritavancin inhibited all strains at ≤0.5 μg/ml. Vancomycin-susceptible and
vanB
-carrying
E. faecium
strains (MIC
50
and MIC
90
, ≤0.008 and ≤0.008 μg/ml for both) were very susceptible to oritavancin, as were VanA-producing isolates (MIC
50
and MIC
90
, 0.03 and 0.06 μg/ml). Oritavancin exhibited good
in vitro
potency against this collection of organisms, including vancomycin-resistant enterococci.
Alkyl Hydroperoxide Reductase Is Required for Helicobacter cinaedi Intestinal Colonization and Survival under Oxidative Stress in BALB/c and BALB/c Interleukin-10
−/−
Mice
Authors: Charoenlap Nisanart , Shen Zeli , McBee Megan E. , Muthupalani Suresh , Wogan Gerald N. , Fox James G. , Schauer David B.
Published: December 2011

Helicobacter cinaedi
, a common human intestinal bacterium, has been implicated in various enteric and systemic diseases in normal and immunocompromised patients. Protection against oxidative stress is a crucial component of bacterium-host interactions. Alkyl hydroperoxide reductase C (AhpC) is an enzyme responsible for detoxification of peroxides and is important in protection from peroxide-induced stress.
H. cinaedi
possesses a single
ahpC
, which was investigated with respect to its role in bacterial survival during oxidative stress. The
H. cinaedi ahpC
mutant had diminished resistance to organic hydroperoxide toxicity but increased hydrogen peroxide resistance compared with the wild-type (WT) strain. The mutant also exhibited an oxygen-sensitive phenotype and was more susceptible to killing by macrophages than the WT strain.
In vivo
experiments in BALB/c and BALB/c interleukin-10 (IL-10)
−/−
mice revealed that the cecal colonizing ability of the
ahpC
mutant was significantly reduced. The mutant also had diminished ability to induce bacterium-specific immune responses
in vivo
, as shown by immunoglobulin (IgG2a and IgG1) serum levels. Collectively, these data suggest that
H. cinaedi ahpC
not only contributes to protecting the organism against oxidative stress but also alters its pathogenic properties
in vivo
.
Competition and Resilience between Founder and Introduced Bacteria in the Caenorhabditis elegans Gut
Authors: Portal-Celhay Cynthia , Blaser Martin J.
Published: December 2011

The microbial communities that reside within the intestinal tract in vertebrates are complex and dynamic. In this report, we establish the utility of
Caenorhabditis elegans
as a model system for identifying the factors that contribute to bacterial persistence and for host control of gut luminal populations. We found that for N2 worms grown on mixed lawns of bacteria,
Salmonella enterica
serovar Typhimurium substantially outcompeted
Escherichia coli
, even when
E. coli
was initially present at 100-fold-higher concentrations. To address whether innate immunity affects the competition, the
daf-2
and
daf-16
mutants were studied; their total gut bacterial levels reflect overall capacity for colonization, but
Salmonella
outcompeted
E. coli
to an extent similar to wild-type worms. To address the role of virulence properties,
Salmonella
Δ
spi-1
Δ
spi-2
was used to compete with
E. coli
. The net differential was significantly less than that for wild-type
Salmonella
; thus,
spi-1 spi-2
encodes
C. elegans
colonization factors. An
E. coli
strain with repeated
in vivo
passage had an enhanced ability to compete against an
in vitro
-passed
E. coli
strain and against
Salmonella
. Our data provide evidence of active competition for colonization niches in the
C. elegans
gut, as determined by bacterial factors and subject to
in vivo
selection.
Phenotypic Characterization of acopAMutant of Neisseria gonorrhoeae Identifies a Link between Copper and Nitrosative Stress
Authors: Djoko Karrera Y. , Franiek Jessica A. , Edwards Jennifer L. , Falsetta Megan L. , Kidd Stephen P. , Potter Adam J. , Chen Nathan H. , Apicella Michael A. , Jennings Michael P. , McEwan Alastair G.
Published: December 2011

NGO0579 is annotatedcopAin theNeisseria gonorrhoeaechromosome, suggesting that it encodes a cation-transporting ATPase specific for copper ions. Compared to wild-type cells, acopAmutant was more sensitive to killing by copper ions but not to other transition metals. The mutant also accumulated a greater amount of copper, consistent with the predicted role of CopA as a copper efflux pump. ThecopAmutant showed a reduced ability to invade and survive within human cervical epithelial cells, although its ability to form a biofilm on the surface of these cells was not significantly different from that of the wild type. In the presence of copper, thecopAmutant exhibited increased sensitivity to killing by nitrite or nitric oxide. Therefore, we concluded that copper ion efflux catalyzed by CopA is linked to the nitrosative stress defense system ofNeisseria gonorrhoeae. These observations suggest that copper may exert its effects as an antibacterial agent in the innate immune system via an interaction with reactive nitrogen species.
Reforming Science: Methodological and Cultural Reforms
Authors: Casadevall Arturo , Fang Ferric C.
Published: December 2011

Contemporary science has brought about technological advances and an unprecedented understanding of the natural world. However, there are signs of dysfunction in the scientific community as well as threats from diverse antiscience and political forces. Incentives in the current system place scientists under tremendous stress, discourage cooperation, encourage poor scientific practices, and deter new talent from entering the field. It is time for a discussion of how the scientific enterprise can be reformed to become more effective and robust. Serious reform will require more consistent methodological rigor and a transformation of the current hypercompetitive scientific culture.
Feasibility of a structured group education session to improve self-management of blood pressure in people with chronic kidney disease: an open randomised pilot trial
Authors: Byrne Jo , Khunti Kamlesh , Stone Margaret , Farooqi Azhar , Carr Sue
Published: December 2011

Objectives

We aimed to test, at pilot level, a structured group educational intervention to improve self-management of blood pressure in people with chronic kidney disease (CKD). The current paper explores patient acceptability of the intervention.

Design

This was an open randomised pilot trial. Participants were randomly assigned to either:

A control group (n=41) receiving standard clinical management of hypertension.

An intervention group (n=40) receiving standard clinical care plus the educational intervention.

Setting

Renal outpatient clinics at a single study centre.

Participants

Patients with early CKD and hypertension were identified and approached for recruitment.

Intervention

An evidence-based structured group educational intervention (CHEERS) using the principles of social cognitive theory to improve knowledge and self-management skills.

Outcomes

Recruitment, uptake of the intervention and patient satisfaction were evaluated to explore patient acceptability of the intervention and to determine any differences between patients regarding recruitment and retention.

Measures

Data on age, sex and ethnicity were collected for all patients approached to take part. For recruited patients, data were also collected on self-efficacy (ability to self-manage). Reasons given by patients declining to take part were recorded. Patients attending the educational session also completed an evaluation form to assess satisfaction.

Results

A total of 267 patients were approached, and 30% were randomly assigned. Lack of time (48%) and lack of interest (44%) were the main reasons cited for non-participation in the study. Men were significantly more likely to be recruited (p=0.048). The intervention was rated enjoyable and useful by 100% of participants. However, 37.5% of the intervention group failed to attend the educational session after recruitment. Participants failing to attend were significantly more likely to be older (p=0.039) and have lower self-efficacy (p=0.034).

Conclusion

The findings suggest that delivering and evaluating an effective structured group educational intervention to promote better blood pressure control in patients with CKD would be challenging in the current context of kidney care.
Evaluation of uplift interpretation criteria for drilled shafts in gravelly soils
Authors: Chen Yit-Jin , Chu Tsu-Hung
Published: December 2011

Representative interpretation criteria are examined in this paper to evaluate the capacity of drilled shaft foundations under axial uplift loading in gravelly soils. A large number of uplift shaft load tests for gravelly soils are used for analysis, and the interpretation criteria are applied to these load test data to establish a consistent uplift interpretation criterion. The statistical results show that the smaller the uplift displacement, the higher the coefficient of variation. In general, the displacements required to mobilize shaft failure load in gravelly soils are larger than those in non-gravelly soils. Based on these analyses, the relative merits and interrelationships of these criteria are established. Specific design recommendations for the evaluation of uplift drilled shaft capacity are given.
Probabilistic version of the Robertson and Wride method for liquefaction evaluation: development and application
Authors: Ku Chih-Sheng , Juang C. Hsein , Chang Chi-Wen , Ching Jianye
Published: December 2011

The Robertson and Wride method is the most widely used cone penetration test (CPT)-based method for soil liquefaction evaluation. This method is a deterministic model, which expresses liquefaction potential in terms of factor of safety. On many occasions, there is a need to express the liquefaction potential in terms of liquefaction probability. Although several probabilistic models are available in the literature, there is an advantage having a probabilistic version of the Robertson and Wride method so that the engineer who prefers to use this method can obtain additional information of liquefaction probability with minimal extra effort. In this paper, a simple model is developed, which links the factor of safety determined by the Robertson and Wride method to the liquefaction probability. The model, referred to as the probabilistic RW model, is developed, and verified, in a mathematically rigorous manner. Simplified equations for assessing the variation of liquefaction probability caused by the uncertainty in input parameters are also developed. Example applications are presented to demonstrate the developed models.
SMALL SIGNAL AND DC CHARACTERISTICS OF ULTRA-THIN GaN/AlN/GaN HFETs
Authors: CHABAK KELSON D. , WALKER DENNIS E. , CRESPO ANTONIO , TREJO MANUEL , KOSSLER MAURICIO , TETLAK STEVE , GILLESPIE JAMES K. , FITCH ROBERT C. , VIA GLEN D. , DABIRAN AMIR , WOWCHAK A.M. , CHOW P.P.
Published: December 2011

This paper presents high performance device results using an ultra-thin AlN / GaN structure on sapphire substrate with a 100-nm T -gate. Excellent dc and RF characteristics are reported, including an extrinsic transconductance of 500 mS/mm and an extrinsic f t / f max ( U ) ratio of 78/111-GHz which is among the highest reported for AlN / GaN HFETs. Low gate leakage results are also presented despite the small barrier thickness and absence of a gate dielectric. Modeling of the small signal parameters is also discussed to gain an understanding of the limiting and contributing performance factors.
EXTRACTION OF GATE CAPACITANCE OF HIGH-FREQUENCY AND HIGH-POWER GaN HEMTs BY MEANS OF CELLULAR MONTE CARLO SIMULATIONS
Authors: GUERRA DIEGO , MARINO FABIO ALESSIO , GOODNICK STEPHEN , FERRY DAVID , SARANITI MARCO
Published: December 2011

A high-frequency a high-power GaN HEMT was analyzed using our full band Cellular Monte Carlo (CMC) simulator, in order to extract small signal parameters and figures of merit, and to correlate them to carrier dynamics and distribution inside the device. A complete RF and DC characterization of the device was performed using experimental data to calibrate the few adjustable parameters of the simulator. Then, gate-related capacitances, such as Cg, Cgd, and Cgs, were directly and indirectly extracted combining small-signal analysis and DC characterization.
PERFORMANCE OF PSEUDOMORPHIC ULTRAVIOLET LEDs GROWN ON BULK ALUMINUM NITRIDE SUBSTRATES
Authors: GIBB SHAWN R. , GRANDUSKY JAMES R. , MENDRICK MARK , SCHOWALTER LEO J.
Published: December 2011

Low dislocation density pseudomorphic epitaxial layers of Al x Ga 1- x N have been grown on c -face AlN substrates prepared from high quality bulk crystals. As reported previously, pseudomorphic growth yields very low dislocation density layers with atomically smooth surfaces throughout the active region of a full LED device structure. An advantage of the low dislocation density is the ability to n -type dope the high aluminum content Al x Ga 1- x N (x ~ 70%) epitaxial layers required for UVLED devices to obtain sheet resistances less than 350 Ohm/square for 0.5 μm thick layers. Here, we report on the characterization of our pseudomorphic epitaxial AlGaN layers via cathodoluminescence (CL) and on-wafer and initial packaged level characterization of fully fabricated pseudomorphic ultraviolet LEDs (PUVLEDs) with an emission wavelength between 250 - 265 nm. An additional benefit of PUVLED devices is the ability to run these devices at high input powers and current densities. Further, the aforementioned low dislocation density of the epitaxial structure results in improved device performance over previously published data. Mean output powers of greater than 4 mW were obtained on-wafer prior to thinning and roughening while output powers as high as 45 mW were achieved for packaged devices.
INTEGRATION OF N- AND P-CONTACTS TO GaN-BASED LIGHT EMITTING DIODES
Authors: HOU WENTING , DETCHPROHM THEERADETCH , WETZEL CHRISTIAN
Published: December 2011

Low-resistance Ohmic contacts are essential for the fabrication of electrical devices. While low contact resistance has been achieved to p -type layers or n -type layers separately, contacts are likely to degrade when both types need to be integrated into a single fabrication process, in particular when prior mesa etching is required. We present a solution to the problem, resulting in low-resistance Ohmic contacts on n -type GaN layers without post-deposition thermal anneal, while maintaining the quality of typical p -type contacts. We implement an integrated process for both, n - and p -contacts, involving an oxygen pretreatment to fabricate light emitting diodes with lower series resistance in the contacts and lower voltage drop at high current when compared to separately optimized contacts.
TIME-RESOLVED PHOTOLUMINESCENCE STUDY OF TYPE II SUPERLATTICE STRUCTURES WITH VARYING ABSORBER WIDTHS
Authors: CONNELLY BLAIR C. , METCALFE GRACE D. , SHEN PAUL H. , WRABACK MICHAEL
Published: December 2011

We report time-resolved photoluminescence measurements on a set of long-wave infrared InAs / GaSb type II superlattice absorber samples with various widths as a function of temperature and excitation density. Careful analysis of the photoluminescence data determines the minority carrier lifetime and background carrier density as a function of temperature, and provides information on the acceptor energy and density in each sample. Results indicate that carrier lifetime is dominated by Shockley-Read-Hall recombination with a lifetime of ~30 ns at 77 K for all samples. Below 40 K, background carriers are observed to freeze-out in conjunction with increased contributions from radiative recombination. An acceptor energy level of ~20 meV above the valance band is also determined for all samples. Variations of carrier lifetime between each sample do not strongly correlate with absorber width, indicating that barrier recombination is not the dominant factor limiting the carrier lifetime in our samples.
APPLICATION OF EPITAXIAL UNIPOLAR BARRIERS TO REDUCE NOISE CURRENTS IN PHOTODETECTORS
Authors: SAVICH G. R. , PEDRAZZANI J. R. , MAIMON S. , WICKS G. W.
Published: December 2011

Tunneling currents and surface leakage currents are both contributors to the overall dark current which limits many semiconductor devices. Surface leakage current is generally controlled by applying a post-epitaxial passivation layer; however, surface passivation is often expensive and ineffective. Band-to-band and trap assisted tunneling currents cannot be controlled through surface passivants, thus an alternative means of control is necessary. Unipolar barriers, when appropriately applied to standard electronic device structures, can reduce the effects of both surface leakage and tunneling currents more easily and cost effectively than other methods, including surface passivation. Unipolar barriers are applied to the p -type region of a conventional, MBE grown, InAs based pn junction structures resulting in a reduction of surface leakage current. Placing the unipolar barrier in the n -type region of the device, has the added benefit of reducing trap assisted tunneling current as well as surface leakage currents. Conventional, InAs pn junctions are shown to exhibit surface leakage current while unipolar barrier photodiodes show no detectable surface currents.