bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stochastic Fatigue Crack Growth Analysis for Space System
Reliability
Authors: Salimi Hossein , Kiad Saeed , Pourgol-Mohammad Mohammad 
Published: July 2017

Abstract
In this study, stochastic analysis is aimed for space structures (satellite in low earth orbit, made of aluminum 2024-T3), with the focus on fatigue failure. Primarily, the deterministic fatigue simulation is conducted using Walker and Forman models with constant amplitude loading. Deterministic crack growth was numerically simulated by the authors developed algorithm and is compared with commercial software for accuracy verification as well as validation with the experimental data. For the stochastic fatigue analysis of this study, uncertainty is estimated by using the Monte Carlo simulation. It is observed that by increasing the crack length, the standard deviation (the measure of uncertainty) increases. Also, it is noted that the reduction in stress ratio has the similar effect. Then, stochastic crack growth model, proposed by Yang and Manning, is employed for the reliability analysis. This model converts the existing deterministic fatigue models to stochastic one by adding a random coefficient. Applicability of this stochastic model completely depends on accuracy of base deterministic function. In this study, existing deterministic functions (power and second polynomial) are reviewed, and three new functions, (i) fractional, (ii) global, and (iii) exponential, are proposed. It is shown that the proposed functions are potentially used in the Yang and Manning model for better results.
The geologic history of seawater pH
Authors: Halevy I. , Bachan A. 
Published: July 2017

The long view of ocean pH
The acid-base balance of the oceans has been critical in maintaining Earth's
habitability and allowing the emergence of early life. Despite this importance,
systematic estimates of historical seawater pH are lacking. Halevy and Bachan
developed a model of seawater chemistry and pH over time scales exceeding
∼100 million years. Their highly robust probabilistic history of seawater
pH and chemistry reflects evolving properties of Earth's atmosphere, oceans, and
crust. Seawater pH increased from early Archean values of ∼6.5 to 7.0 to
more recent values of ∼7.5 to 9.0 mostly as a result of solar brightening
and decreasing interaction between seawater and oceanic crust.

Science
, this issue p.
1069
Evaluation of Combination Drug Therapy for Treatment of Antibiotic-Resistant Inhalation Anthrax in a Murine Model
Authors: Heine H. S. , Shadomy S. V. , Boyer A. E. , Chuvala L. , Riggins R. , Kesterson A. , Myrick J. , Craig J. , Candela M. G. , Barr J. R. , Hendricks K. , Bower W. A. , Walke H. , Drusano G. L. 
Published: July 2017

ABSTRACT

Bacillus anthracis
is considered a likely agent to be used as a bioweapon, and the use of a strain resistant to the first-line antimicrobial treatments is a concern. We determined treatment efficacies against a ciprofloxacin-resistant strain of
B. anthracis
(Cip
r
Ames) in a murine inhalational anthrax model. Ten groups of 46 BALB/c mice were exposed by inhalation to 7 to 35 times the 50% lethal dose (LD
50
) of
B. anthracis
Cip
r
Ames spores. Commencing at 36 h postexposure, groups were administered intraperitoneal doses of sterile water for injections (SWI) and ciprofloxacin alone (control groups), or ciprofloxacin combined with two antimicrobials, including meropenem-linezolid, meropenem-clindamycin, meropenem-rifampin, meropenem-doxycycline, penicillin-linezolid, penicillin-doxycycline, rifampin-linezolid, and rifampin-clindamycin, at appropriate dosing intervals (6 or 12 h) for the respective antibiotics. Ten mice per group were treated for 14 days and observed until day 28. The remaining animals were euthanized every 6 to 12 h, and blood, lungs, and spleens were collected for lethal factor (LF) and/or bacterial load determinations. All combination groups showed significant survival over the SWI and ciprofloxacin controls: meropenem-linezolid (
P
= 0.004), meropenem-clindamycin (
P
= 0.005), meropenem-rifampin (
P
= 0.012), meropenem-doxycycline (
P
= 0.032), penicillin-doxycycline (
P
= 0.012), penicillin-linezolid (
P
= 0.026), rifampin-linezolid (
P
= 0.001), and rifampin-clindamycin (
P
= 0.032). In controls, blood, lung, and spleen bacterial counts increased to terminal endpoints. In combination treatment groups, blood and spleen bacterial counts showed low/no colonies after 24-h treatments. The LF fell below the detection limits for all combination groups yet remained elevated in control groups. Combinations with linezolid had the greatest inhibitory effect on mean LF levels.
Sterilizing Effect of Ertapenem-Clavulanate in a Hollow-Fiber Model of Tuberculosis and Implications on Clinical Dosing
Authors: van Rijn Sander P. , Srivastava Shashikant , Wessels Mireille A. , van Soolingen Dick , Alffenaar Jan-Willem C. , Gumbo Tawanda 
Published: July 2017

ABSTRACT

Carbapenems are now being explored for treatment of multidrug-resistant tuberculosis (MDR-TB), especially in conjunction with clavulanate. Clinical use is constrained by the need for multiple parenteral doses per day and the lack of knowledge of the optimal dose for sterilizing effect. Our objective was to identify the ertapenem exposure associated with optimal sterilizing effect and then design a once-a-day dose for clinical use. We utilized the hollow-fiber system model of tuberculosis in a 28-day exposure-response study of 8 different ertapenem doses in combination with clavulanate. The systems were sampled at predetermined time points to verify the concentration-time profile and identify the total bacterial burden. Inhibitory sigmoid maximum-effect (
E
max
) modeling was used to identify the relationship between total bacterial burden and the drug exposure and to identify optimal exposures. Contrary to the literature, ertapenem-clavulanate combination demonstrated good microbial kill and sterilizing effect. In a dose fractionation hollow-fiber study, efficacy was linked to percentage of the 24-h dosing interval of ertapenem concentration persisting above MIC (%
T
MIC
). We performed 10,000 MDR-TB patient computer-aided clinical trial simulations, based on Monte Carlo methods, to identify the doses and schedule that would achieve or exceed a %
T
MIC
of ≥40%. We identified an intravenous dosage of 2 g once per day as achieving the target in 96% of patients. An ertapenem susceptibility breakpoint MIC of 2 mg/liter was identified for that dose. An ertapenem dosage of 2 g once daily is the most suitable to be tested in a phase II study of sterilizing effect in MDR-TB patients.
In Vivo
Analysis of the Viable Microbiota and Helicobacter pylori Transcriptome in Gastric Infection and Early Stages of Carcinogenesis
Authors: Thorell Kaisa , Bengtsson-Palme Johan , Liu Oscar Hsin-Fu , Palacios Gonzales Reyna Victoria , Nookaew Intawat , Rabeneck Linda , Paszat Lawrence , Graham David Y. , Nielsen Jens , Lundin Samuel B. , Sjöling Åsa 
Published: July 2017

ABSTRACT

Emerging evidence shows that the human microbiota plays a larger role in disease progression and health than previously anticipated.
Helicobacter pylori
, the causative agent of gastric cancer and duodenal and gastric ulcers, was early associated with gastric disease, but it has also been proposed that the accompanying microbiota in
Helicobacter pylori
-infected individuals might affect disease progression and gastric cancer development. In this study, the composition of the transcriptionally active microbial community and
H. pylori
gene expression were determined using metatranscriptomic RNA sequencing of stomach biopsy specimens from individuals with different
H. pylori
infection statuses and premalignant tissue changes. The results show that
H. pylori
completely dominates the microbiota not only in infected individuals but also in most individuals classified as
H. pylori
uninfected using conventional methods. Furthermore,
H. pylori
abundance is positively correlated with the presence of
Campylobacter
,
Deinococcus
, and
Sulfurospirillum
. Finally, we quantified the expression of a large number of
Helicobacter pylori
genes and found high expression of genes involved in pH regulation and nickel transport. Our study is the first to dissect the viable microbiota of the human stomach by metatranscriptomic analysis, and it shows that metatranscriptomic analysis of the gastric microbiota is feasible and can provide new insights into how bacteria respond
in vivo
to variations in the stomach microenvironment and at different stages of disease progression.
Learning from Adversity?
Authors: Bourret Robert B. 
Published: July 2017

ABSTRACT

Many two-component regulatory systems, including
Escherichia coli
PhoRB, are positively autoregulated, so stimuli result in an increase in the concentration of signaling proteins. When the quantity of signaling proteins depends on exposure history, how do past conditions affect future responses to stimuli? Hoffer et al. (J. Bacteriol. 183:4914–4917, 2001,
https://doi.org/doi:10.1128/JB.183.16.4914-4917.2001
) previously reported that
E. coli
bacteria “learn” from phosphate starvation and respond more rapidly to subsequent episodes of starvation. Gao et al. (J. Bacteriol. 199:e00390-17, 2017,
https://doi.org/doi:10.1128/JB.00390-17
) describe another aspect of hysteresis in the PhoRB regulon. Phosphate starvation also leads to a global decline in transcription, counteracting the effects of positive autoregulation and resulting in a similar net
pho
response (homeostasis), regardless of exposure history.
Understanding the trigger for the LUSI mud volcano eruption from ground deformation signatures
Authors: Andreas Heri , Abidin Hasanuddin Z. , Sidiq Teguh P. , Gumilar Irwan , Aoki Yosuke , Hakim Agus L. , Sumintadiredja Prihadi 
Published: July 2017

Abstract

The LUSI mud volcano in the sub-district of Porong, Sidoarjo, East Java, Indonesia started to erupt on 29 May 2006. An almost continuous eruption of a mixture of mud, water and gas has occurred around this area since this date. The eruption triggered vertical and horizontal ground deformation. From June 2006 to December 2010, 14 global positioning system campaigns were conducted to observe the ground deformation using
c.
50 stations sparsely located up to 10 km from the eruption centre. Field observations of cracks, terrestrial laser scanning and geo-electrical measurements have also been used to infer the ground deformation signature around the LUSI mud volcano. More than 150 pairs of interferograms generated from 66 ALOS PALSAR images from June 2006 to December 2009 have also been used to study the ground deformation caused by the LUSI mud volcano. The LUSI mud eruption began only 200 m from where the Lapindo Inc. oil company was drilling for oil and gas. The drilling may have pierced a deeper high-pressure zone, causing an underground blow-out of the drillhole into a hydrofracture. Alternatively, the magnitude 6.3 Yogyakarta earthquake, which was located
c.
275 km from the eruption site and occurred two days before the LUSI eruption, may have shaken the area sufficiently to cause the eruption by reactivating a fault in the region and liquefying the mud. These two hypotheses for triggering the mud volcano have been argued vehemently and still remain controversial. The ground deformation signatures provide important clues to understanding the trigger for the eruption and to solve this controversy. Co-seismic fault reactivation has its own typical ground deformation signature. This study used global positioning system and InSAR techniques, as well as field observations of cracks, terrestrial laser scanning and geo-electrical measurements, to determine the signature of ground deformation around the LUSI mud volcano and to explain the triggering mechanism.
Reconstruction of Thermodynamic Cycles in a High-Resolution Simulation of a Hurricane
Authors: Pauluis Olivier M. , Zhang Fuqing 
Published: July 2017

Abstract
The relationship between energy transport and kinetic energy generation in a hurricane is analyzed. The hydrological cycle has a negative impact on the generation of kinetic energy. First, in a precipitating atmosphere, mechanical work must also be expended in order to lift water. Second, the injection of water vapor at low relative humidity and its removal through condensation and precipitation reduces the ability of a thermodynamic cycle to generate work. This reduction can be directly quantified in terms of the change in the Gibbs free energy between the water added and removed.
A newly developed approach—namely, the mean airflow as Lagrangian dynamics approximation— is used to extract thermodynamic cycles from the standard output of a numerical simulation of a hurricane. While convection in the outer rainbands is inefficient at producing kinetic energy, the deepest overturning circulation associated with the rising air within the eyewall is an efficient heat engine that produces about 70% as much kinetic energy as a comparable Carnot cycle. This confirms that thermodynamic processes play a central role in hurricane formation and intensification and that the thermodynamic cycles in a hurricane are characterized by high generation of kinetic energy that differ significantly from those found in atmospheric convection.
Interannual Variation of the Summer Rainfall Center in the South China Sea
Authors: Chen Tsing-Chang , Tsay Jenq-Dar , Matsumoto Jun 
Published: July 2017

Abstract
A northwest–southeast-oriented summer monsoon trough exists between northern Indochina and northwestern Borneo. Ahead of this the South China Sea (SCS) trough is located at a convergent center west of the Philippines, which provides an environment favorable for rain-producing synoptic systems to produce rainfall over this center and form the SCS summer rainfall center. Revealed from the x–t diagram for rainfall, this rainfall center is developed by multiple-scale processes involved with the SCS trough (TR), tropical depression (TY), interaction of the SCS trough with the easterly wave/tropical depression (EI), and easterly wave (EW). It is found that 56% of this rainfall center is produced by the SCS trough, while 41% is generated by the other three synoptic systems combined. Apparently, the formation of the SCS summer monsoon rainfall center is contributed to by these four rain-producing synoptic systems from the SCS and the Philippines Sea. The Southeast Asian summer monsoon undergoes an interannual variation and exhibits an east–west-oriented cyclonic (anticyclonic) anomalous circulation centered at the western tropical Pacific east of the Luzon Strait. This circulation change is reflected by the deepening (filling) of the SCS summer monsoon trough, when the monsoon westerlies south of 15°N intensify (weaken). This interannual variation of the monsoon westerlies leads to the interannual variation of the SCS summer monsoon rainfall center to follow the Pacific–Japan oscillation of rainfall. The rainfall amount produced over this rainfall center during the weak monsoon season is about two-thirds of that produced during the strong monsoon season. The rain-production ratio between TR and TY + EI + EW is 60:38 during the strong monsoon season and 47:49 during the weak monsoon season.
Application of Surface Spline Interpolation in Inversion of Bottom Friction Coefficients
Authors: Guo Zheng , Pan Haidong , Fan Wei , Lv Xianqing 
Published: July 2017

AbstractA new method for the inversion of bottom friction coefficients (BFCs) in a two-dimensional tidal model is proposed in this study. In this method, the field of BFCs is constructed by interpolating values at independent points using a surface spline. The surface spline interpolation has an advantage: that the constructed surface is smoother than the surface constructed by the traditionally used linear interpolation, which has unrealistic extrema. The method is validated in twin experiments where the prescribed nonlinear distribution of BFCs are better inverted with the surface spline interpolation. In practical experiments, the BFCs are inverted and the M2 tide in the Bohai Sea is simulated by assimilating the TOPEX/Poseidon (T/P) data. The small errors between the simulation results and the observations, as well as the accurate cotidal charts, demonstrate the feasibility of the new method in practical application.
Well-being and perceptions of everyday activities among those who attend community-based day centres for people with mental illness in Sweden – Does an immigrant background make a difference?
Authors: Pooremamali Parvin , Eklund Mona 
Published: July 2017

Background: Community-based day centres (CBDCs) for people with mental illness are a common service for both people with an immigrant background and native Swedes. Aim: The aim was to compare CBDC attendees with an immigrant background with attendees who were native Swedes in terms of well-being and perceptions of everyday activities and investigate whether ethnic background could predict these factors. Methods: Attendees at nine CBDCs were invited to participate. In all, 56 with an immigrant background and 69 native Swedes completed self-report questionnaires that addressed various aspects of well-being and everyday activities. Results: Attendees with an immigrant background had a worse situation regarding perceived self-esteem, empowerment and satisfaction with everyday activities. In multivariate logistic regression analyses, ethnic background only became a significant predictor in regard to empowerment. Quality of life and activity level were of importance for satisfaction with everyday activities. Empowerment and self-esteem mutually influenced each other. Conclusion: Having a mental illness and an immigrant background may infer a particular risk for low empowerment. The mental health services and society at large should consider measures for adjusting the support to this group, including an analysis of how environments and contexts may act as barriers to activity enrichment and culturally congruent support.
Stigma-related mental health knowledge and attitudes among primary health workers and community health volunteers in rural Kenya
Authors: Mutiso Victoria N , Musyimi Christine W , Nayak Sameera S , Musau Abednego M , Rebello Tahilia , Nandoya Erick , Tele Albert K , Pike Kathleen , Ndetei David M 
Published: July 2017

Background: The study was conducted in rural Kenya and assessed stigma in health workers from primary health facilities. Aims: This study compared variations in stigma-related mental health knowledge and attitudes between primary health workers (HWs) and community health volunteers (CHVs). Methods: Participants ( n = 44 HWs and n = 60 CHVs) completed the self-report Mental Health Knowledge Schedule and the Reported and Intended Behavior Scale, along with sociodemographic questions. Multiple regression models were used to assess predictors of mental health knowledge and stigmatizing behaviors. Results: HWs had significantly higher mean mental health knowledge scores than CHVs, p < .001, and significantly higher mean positive attitudes scores than CHVs, p = .042. When controlling for relevant covariates, higher positive attitudes was the only significant predictor of higher mental health knowledge, and self-rating of sense of belonging to the community and mental health knowledge remained the main predictors of positive attitudes. Conclusion: Results suggest that stigma-related mental health knowledge and attitudes are associated, and interventions should target these areas with health workers. There is scope for intervention to increase knowledge and positive attitudes for individuals who feel a strong sense of community belonging. Future studies should test feasible ways to reduce stigma in this population.
New Additive Solutions for Low VOC in HR Molded Foams
Authors: Sikorski Matthias , Wehman Cor , Cordelair Holger 
Published: July 2017

There is strong pressure on the suppliers of flexible molded foam for automotive seating to reduce the amount of volatile organic compounds (VOC) in their products. At the moment the main sources of VOC are the catalysts and silicone surfactants. The most effective means to reduce or even eliminate the VOC originating from the amine catalysts would be the use of amines containing reactive groups such as primary or secondary amine and/or hydroxyl groups. These loose however a lot of their activity when they are built into the foam structure, which hence might lead to insufficient flow and / or curing. A careful balance of chemical reactivities and catalytic activities is therefore needed. Nitroil(r) Performance Chemicals carried out a study on the performance of a number of such reactive amine catalysts, in combination with other reactive or non-reactive amines. The main focus was of course on VOC, but maintenance of acceptable processing and physical foam properties was another major requirement. A series of combinations were evaluated in a TDI-based standard formulation and compared to a combination of traditionally used non-reactive amine catalysts. In this presentation, it will be shown that the use of reactive amines led to a considerable reduction of VOC. By using only reactive amines, a VOC reduction of ca. 50% was obtained, and virtually no amine was present in the VOC. Good foam processing was obtained while physical foam properties were not significantly affected, with the exception of HACS. This property suffered from the use of reactive amines. By using PC CATS HPI as the basic catalyst in combination with a non-reactive amine as "blow" catalyst, the values for all physical foam properties, including humid aging compression set (HACS), were quite acceptable, while a VOC reduction of ca. 20% was obtained.
Employment of Zero ODP Blowing Agents for Polyurethane Rigid Foams for Thermal Insulation
Authors: Cecchini C. , Cancellier V. , Cellarosi B. 
Published: July 2017

The problem of ozone depletion in the atmosphere is becoming more and more important. Consequently, many countries introduced more restrictive regulations in comparison with the Montreal Protocol and its subsequent revisions, anticipating the phaseout of CFC. The introduction of HCFCs, whose molecules are less harmful to the ozone, is entering a transitional period awaiting more conclusive solutions (e.g., zeroODP systems). In this respect EniChem has been concentrating its efforts insetting up systems for the production of PU rigid foams blown with HFC-134afor thermal insulation. Significant progress has been made on the employment of this blowing agent in the refrigeration application. Initial thermal conductivity values at 230°C of about 21 mW/mK in real cabinets were obtained, comparable to that of reduced CFC-11 systems currently used in the market. Energy consumption data were also equivalent to reduced CFC-1l-containing refrigerators. Further research allowed us to also extend the employment of this blowing agent for production of continuous panels, overcoming the problem of excessive "frothing effect" that until now limited the use of low boiling agents in this field. Good material distribution and mechanical characteristics were obtained, and in particular again a thermal conductivity value at 230°C of 21mW/mK. The most interesting alternative, from the technological and scientific point of view, however, is the blowing obtained only by CO2, which is produced by there action between water and isocyanate. EniChem/PU Division research in this respect has been basically directed to the reduction of initial and aged X value, without leaving out other important aspects, like dimensional stability and adhesion to facers. The results of this research allowed the achievement of interesting performances both in the continuous panels and in the refrigeration cabinets production, demonstrating the possibility of strongly reducing initial thermal conductivity down to 22 mW/mK at 230°C. Moreover, use of PU matrixes of lower permeability to CO2, with respect to normally accepted values, limited the aging problem so that after 3 months at room temperature a panel without skin,40 mm thick, increased its thermal conductivity value only 10%.