bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unix
Authors: Fox Christopher 
Published: February 2015

AbstractThe UNIX system is a computer operating system and a collection of software tools created at AT&T Bell Laboratories in the early 1970s. UNIX is a registered trademark of UNIX System Laboratories, Inc. Today the UNIX system is among the most popular and widely used computing environments, and is found on computers ranging from laptops through supercomputers. This article discusses the history and development of the UNIX system, its structure, its influence, its strengths and weaknesses as a software engineering environment, and its future.
Viruses
Authors: Chess David M. , Spafford Eugene H. 
Published: February 2015

AbstractComputers are designed to execute instructions one after another. Those instructions usually do something useful—calculate values, maintain databases, and communicate with users and with other systems. Sometimes, however, the instructions executed can be damaging or otherwise undesirable. When that happens by accident, we call the code involved a “software bug”—perhaps the most common cause of unexpected program behavior. If the source of the instructions was an individual who intended that the abnormal behavior occur, then we consider this malicious coding; programs containing malicious code are sometimes referred to asmalwareorvandalware.Many distinct programmed threats are characterized by the way they behave, how they are triggered, and how they spread. Occurrences of malware have been described almost uniformly by the media ascomputer viruses. Viruses are widespread, but they are not responsible for many of the problems attributed to them.The essential quality of a computer virus, which differentiates it from other types of malware and software misbehavior, is the ability to spread.A typical computer virus is a segment of machine code or other programming instructions that will copy itself (or a modified version of itself) into one or more larger “host” programs when it is activated. When these infected programs are run, the viral code is executed and the virus spreads further. Sometimes, what constitutes “programs” is more than simply applications; boot code, device drivers, command interpreters, and even electronic documents also can be infected.Several informal definition of viruses are described. Examples of real‐life viruses are given. Virus structure technology and operation are discussed. Defences against viruses such as Scanners, activity monitor, and integrity checkers are detailed.
Earned Value
Authors: Servello Mark , Marciniak John J. 
Published: February 2015

Abstract

The concept of earned value is a powerful method to track the cost, schedule, and work progress of a project. Earned value relies on budgeting labor and costs against tasks in the project hierarchy, typically against a work breakdown structure (WBS) defining meaningful tasks that accomplish pieces of the total project work. In a product development or modification project, tasks create pieces of the product, so task accomplishment is a direct measure of progress. When costs incurred by the project are collected against tasks in the WBS, earned value is integrated with progress, cost and schedule status reporting. In the U.S. government, this is typically through systems such as
cost/schedule control systems criteria
(C/SCSC). These systems provide a method for reporting on the costs associated with systems development.

In an earned‐value system, development or modification of a product is broken down into measurable, manageable pieces of work called
tasks
. The resulting projection is the planned work to complete the project, termed the
budgeted cost of work scheduled
(BCWS). By comparing this projection with actual tasks accomplished, labor consumed, and costs incurred from the ongoing project, we can arrive at cost and schedule status and variances.

The basic terms of earned value are BCWS
Pi2 pulsations observed around the dawn terminator
Authors: Imajo S. , Yoshikawa A. , Uozumi T. , Ohtani S. , Nakamizo A. , Marshall R. , Shevtsov B. M. , Akulichev V. A. , Sukhbaatar U. , Liedloff A. , Yumoto K. 
Published: February 2015

AbstractWe examined Pi2 pulsations observed simultaneously at low‐latitude stations (L = 1.15 − 2.33) around the dawn terminator. Those Pi2 pulsations observed in the sunlit region were polarized in the azimuthal (D, positive eastward) direction. We found that the D component oscillations in the dark and sunlit regions were in antiphase, whereas the H component oscillated in phase. A statistical analysis indicates that these D component phase reversals occurred about 0.5 h sunward of the dawn terminator at 100 km in altitude, corresponding to the highly conducting E layer. The azimuthal polarization and D component phase reversals related to the dawn terminator cannot be explained by the existing models of low‐latitude Pi2s (e.g., cavity resonance or substorm current wedge oscillations). Similar D component phase reversals were also found on the dusk side although the amplitude of the D component is smaller than that of the H component. We suggest that the meridional ionospheric current in the sunlit region adjacent to the dawn terminator drives the D component oscillations in antiphase with those D oscillations produced by the oscillatory field‐aligned current (FAC) on the postmidnight side. The meridional current is expected to form a part of a current system that extends from the postmidnight FAC to the equatorial Cowling current. The D component oscillations in the Northern and Southern Hemispheres are also in antiphase, indicating that the current system is symmetric with respect to the equator.
Nitrogen and phosphorus fluxes from watersheds of the northeast U.S. from 1930 to 2000: Role of anthropogenic nutrient inputs, infrastructure, and runoff
Authors: Hale Rebecca L. , Grimm Nancy B. , Vörösmarty Charles J. , Fekete Balazs 
Published: February 2015

AbstractAn ongoing challenge for society is to harness the benefits of nutrients, nitrogen (N) and phosphorus (P), while minimizing their negative effects on ecosystems. While there is a good understanding of the mechanisms of nutrient delivery at small scales, it is unknown how nutrient transport and processing scale up to larger watersheds and whole regions over long time periods. We used a model that incorporates nutrient inputs to watersheds, hydrology, and infrastructure (sewers, wastewater treatment plants, and reservoirs) to reconstruct historic nutrient yields for the northeastern U.S. from 1930 to 2002. Over the study period, yields of nutrients increased significantly from some watersheds and decreased in others. As a result, at the regional scale, the total yield of N and P from the region did not change significantly. Temporal variation in regional N and P yields was correlated with runoff coefficient, but not with nutrient inputs. Spatial patterns of N and P yields were best predicted by nutrient inputs, but the correlation between inputs and yields across watersheds decreased over the study period. The effect of infrastructure on yields was minimal relative to the importance of soils and rivers. However, infrastructure appeared to alter the relationships between inputs and yields. The role of infrastructure changed over time and was important in creating spatial and temporal heterogeneity in nutrient input‐yield relationships.
Thermoelasticity of Fe2+‐bearing bridgmanite
Authors: Shukla Gaurav , Wu Zhongqing , Hsu Han , Floris Andrea , Cococcioni Matteo , Wentzcovitch Renata M. 
Published: February 2015

AbstractWe present local density approximation augmented by the Hubbard‐type correction calculations of high‐temperature elastic properties of bridgmanite with composition for 0≤×≤0.125. Results of elastic moduli and acoustic velocities for the Mg end‐member (x=0) agree very well with the latest high‐pressure and high‐temperature experimental measurements. In the iron‐bearing system, we focus particularly on the change in thermoelastic parameters across the state change that occurs in ferrous iron above ∼30 GPa, often attributed to a high‐spin (HS) to intermediate‐spin (IS) crossover but explained by first‐principles calculations as a lateral displacement of substitutional iron in the perovskite cage. We show that the measured effect of this change on the equation of state of this system can be explained by the lateral displacement of substitutional iron and not by the HS to IS crossover. The calculated elastic properties of along an adiabatic mantle geotherm somewhat overestimate longitudinal velocities but produce densities and shear velocities quite consistent with the Preliminary Reference Earth Model data throughout most of the lower mantle.
Ionospheric plasma bubbles observed concurrently by multi‐instruments over low‐latitude station Hainan
Authors: Wang G. J. , Shi J. K. , Reinisch B. W. , Wang X. , Wang Z. 
Published: February 2015

AbstractPrevious studies have shown that the ionospheric “strong range spread F” (SSF) closely correlates with the occurrence of scintillations caused by equatorial plasma bubbles. However, there is no report on concurrent observations of SSF and bubbles with in situ measurement. This paper discusses two cases of concurrent observations with a DPS4 Digisonde and a collocated scintillation monitor at the low‐latitude station Hainan (19.5°N, 109.1°E), and with in situ ion density measurements made by the ROCSAT‐1 satellite. Two case studies were made for 10 and 23 April 2004, respectively. In both cases, the SSF occurred before midnight and lasted more than 3.5 h. The scintillations were accompanied with strong range SF. Concurrently, the ROCSAT‐1 satellite observed plasma bubbles over Hainan station. In the first case, two bubbles were observed by the satellite with east‐west sizes of more than ~200 km over Hainan station. Two bubbles were also observed in the second case with east‐west extensions of about 220 km and 35 km, respectively. For the first time, direct observational evidence is provided for the causal relationship between equatorial plasma bubbles with in situ measurement and the concurrent occurrence of SSF and strong scintillations.
Dynamics of sprite streamers in varying air density
Authors: Qin Jianqi , Pasko Victor P. 
Published: February 2015

AbstractSimilarity laws for streamer discharges, which state that the properties of streamers such as streamer radius, electric field, and electron density should respectively scale as N−1, N1, and N2 in different but uniform air densities N, are important relations that have provided a general understanding of the mesospheric sprite discharges based on existing knowledge of streamers in laboratory conditions. Recent modeling studies, however, show that the properties of sprite streamers in varying air density do not follow exactly or even contradict the similarity relations. We present here simulation results and related analysis of sprite streamers to provide a unified view and resolve these contradictions. Our results indicate that the properties of streamers in varying air density are determined by the physical dimensions of streamers and the reduced electric field E/N, with the varying air density N being only one of the three factors controlling the streamer properties.
Post‐traumatic Stress Disorder
Authors: Frueh B. Christopher 
Published: February 2015

AbstractTraumatic event exposure is common and is a risk factor for post‐traumatic stress disorder (PTSD) and other psychiatric problems. Fortunately, rates of PTSD after trauma are relatively low in both civilians and combat veterans (2–14%), and about half of those who develop the disorder will remit over time. Nevertheless, because of its etiological component (i.e., trauma) PTSD has become one of the most common conditions invoked in forensic contexts (both criminal justice and disability). For example, PTSD disability claims by veterans has reached historically unprecedented high levels and continue to rise. Careful forensic assessment is necessary to separate malingering and symptom overreporting from actual PTSD. Strategies for thorough assessment of clinical symptoms and functioning are suggested.
Growth velocity and weaning δ15N “Dips” during ontogeny in Macaca mulatta
Authors: Reitsema Laurie J. , Muir Andrew B. 
Published: February 2015

ABSTRACTObjectives:A “dip” in the stable nitrogen isotope ratios (δ15N) of subadults in the late weaning/early post‐weaning phase of growth and development has been observed. Speculatively, this is the mechanism of positive nitrogen balance operating among rapidly growing subadults. An alternate hypothesis for δ15N dips is that during weaning, subadults eat lower‐15N foods than adults.Methods:This study explores the role of positive nitrogen balance in affecting δ15N variation of growing subadults by comparing growth velocity with stable carbon isotope (δ13C) and δ15N ratios of blood serum from captive rhesus macaques (Macaca mulatta) (n = 14) with controlled diets during the first 10 months of life.Results:During the first six months, δ15N values are inversely correlated with growth in some of the anthropometrics (weight and sagittal circumference). Dips in some infants' δ15N values below their mothers' values are observed at the end of the weaning period. However, during this time frame, δ15N values of the infants are not correlated with anthropometric indices. Serum stable isotope ratios of lactating and non‐lactating adult females differ significantly.Conclusions:Growth in body mass and size explains some of the variation in infant δ15N values, but are not responsible for dips in the late weaning/early post‐weaning phase. It is advised that future research evaluate the extent to which growth in other body systems affects nitrogen balance and δ15N dips during ontogeny, and expand on isotopic differences between lactating and non‐lactating females. Am J Phys Anthropol 157:347–357, 2015. © 2015 Wiley Periodicals, Inc.
You are not what you eat during physiological stress: Isotopic evaluation of human hair
Authors: D'Ortenzio Lori , Brickley Megan , Schwarcz Henry , Prowse Tracy 
Published: February 2015

ABSTRACTVariation in δ13C and δ15N values can be assessed to understand not only diet, but also the influence of physiological factors on an individual. The metabolic balance of an individual can impact isotopic signals in tissues that are forming during the periods of metabolic stress. Fluctuating δ15N values are associated with physiological stressors that alter an individual's metabolism such as infection, injury, or pregnancy. This study examines variation in δ13C and δ15N values along sequentially segmented hair in both modern and archaeological individuals. Subjects with an observable skeletal pathology, known chronic illness, or evidence of pregnancy were compared with controls exhibiting no evidence of physiological stress. The results on hair samples from individuals from 19th century Belleville, Ontario, four modern cadavers (two with cancer and two sudden deaths), and two living pregnant women indicate that δ15N values are approximately 1‰ higher in individuals with a pathological condition (e.g., infection, fracture, or cancer) and are 1‰ lower during pregnancy, whereas δ13C values show less variability. Higher nitrogen values may represent the recycling of nitrogen derived from the breakdown of existing proteins in the body (catabolism), whereas lower δ15N values are related to increased utilization of dietary and urea nitrogen for tissue synthesis during pregnancy. These findings suggest that short‐term fluctuations of δ15N values may be the result of changes in an individual's metabolic balance, and that metabolic imbalance poses a confounding factor to ancient dietary studies when using rapidly growing tissues such as hair. Am J Phys Anthropol 157:374–388, 2015. © 2015 Wiley Periodicals, Inc.
Silver‐Mediated Oxidative Aliphatic CH Trifluoromethylthiolation
Authors: Guo Shuo , Zhang Xiaofei , Tang Pingping 
Published: February 2015

AbstractThe first example of a practical and direct trifluoromethylthiolation reaction of unactivated aliphatic CH bonds employs a silver‐based reagent. The reaction is operationally simple, scalable, and proceeds under aqueous conditions in air. Furthermore, its broad scope and good functional‐group compatibility were demonstrated by applying this method to the selective trifluoromethylthiolation of natural products and natural‐product derivatives.
Nickel‐Catalyzed Amination of Aryl Chlorides with Ammonia or Ammonium Salts
Authors: Green Rebecca A. , Hartwig John F. 
Published: February 2015

AbstractThe nickel‐catalyzed amination of aryl chlorides to form primary arylamines occurs with ammonia or ammonium sulfate and a well‐defined single‐component nickel(0) precatalyst containing a Josiphos ligand and an η2‐bound benzonitrile ligand. This system also catalyzes the coupling of aryl chlorides with gaseous amines in the form of their hydrochloride salts.
Integrating responsible conduct of research education into undergraduate biochemistry and molecular biology laboratory curricula
Authors: Hendrickson Tamara L. 
Published: February 2015

AbstractRecently, a requirement for directed responsible conduct in research (RCR) education has become a priority in the United States and elsewhere. In the US, both the National Institutes of Health and the National Science Foundation require RCR education for all students who are financially supported by federal awards. The guidelines produced by these agencies offer useful templates for the introduction of RCR materials into courses worldwide. Many academic programs already offer courses or workshops in RCR for their graduate students and for undergraduate science majors and/or researchers. Introducing RCR into undergraduate biochemistry and molecular biology laboratory curricula is another, highly practical way that students can be exposed to these important topics. In fact, a strong argument can be made for integrating RCR into laboratory courses because these classes often introduce students to a scientific environment like that they might encounter in their careers after graduation. This article focuses on general strategies for incorporating explicit RCR education into biochemistry and molecular biology laboratory coursework using the topics suggested by NIH as a starting point. © 2015 by The International Union of Biochemistry and Molecular Biology, 43(2):68–75, 2015.
Impact of Environmental Performance on Firm Value for Sustainable Investment: Evidence from Large US Firms
Authors: Yadav Prayag Lal , Han Seung Hun , Rho Jae Jeung 
Published: February 2015

AbstractThis research examines the impact of environmental performance on firm value, applying the event study methodology to Newsweek’s ‘Green Rankings’ announcement of 2012 for large US firms. Specifically, it analyzes the impact of the absolute green score and green rank of firms on their performance in the stock market. We found that investors perceive the announcement as positive news, leading to significant positive standardized cumulative abnormal returns (SCARs). After controlling for industry‐ and firm‐specific effects, we observed that firms with repeated green rankings for enhancing environmental performance showed significantly higher SCARs than those with either reduced or unchanged environmental performance. In addition, the environmental impact score measuring environmental damage from a firm's operational activities was found to be the most influential factor in improving the firm's value. Our findings are beneficial to managers in allocating resources to different types of environmental initiative, and provide valuable insight for sustainable environmental investment. Copyright © 2014 John Wiley & Sons, Ltd and ERP Environment
Sustainable Entrepreneurship: A Convergent Process Model
Authors: Belz Frank Martin , Binder Julia Katharina 
Published: February 2015

AbstractSustainable entrepreneurship pursues a triple bottom line approach of economic, social and ecological goals. The main aim of this paper is to add to our understanding of the process of sustainable entrepreneurship. Since the field of sustainable entrepreneurship is in a nascent stage, we conduct a qualitative study. We employ a multiple case study design to build theory. Based on four case studies we develop a model, which describes the process of sustainable entrepreneurship, including six phases: 1) recognizing a social or ecological problem; 2) recognizing a social or ecological opportunity; 3) developing a double bottom line solution; 4) developing a triple bottom line solution; 5) funding and forming of a sustainable enterprise; 6) creating or entering a sustainable market. By developing a convergent process model with two pathways, we make theoretical contributions to the emerging fields of sustainable entrepreneurship and social entrepreneurship. A key finding is that the triple bottom line of ecological, social and economic goals is integrated sequentially, not simultaneously. Copyright © 2015 John Wiley & Sons, Ltd and ERP Environment.
BRAF mutation is not predictive of long‐term outcome in papillary thyroid carcinoma
Authors: Henke Lauren E. , Pfeifer John D. , Ma Changquing , Perkins Stephanie M. , DeWees Todd , El‐Mofty Samir , Moley Jeffrey F. , Nussenbaum Brian , Haughey Bruce H. , Baranski Thomas J. , Schwarz Julie K. , Grigsby Perry W. 
Published: February 2015

AbstractThe BRAF mutation occurs commonly in papillary thyroid carcinoma (PTC). Previous investigations of its utility to predict recurrence‐free survival (RFS) and disease‐specific survival (DSS) have reported conflicting results and its role remains unclear. The purpose of this retrospective study was to determine the incidence of the BRAF mutation and analyze its relationship to clinicopathologic risk factors and long‐term outcomes in the largest, single‐institution American cohort to date. BRAF mutational status was determined in 508 PTC patients using RFLP analysis. The relationships between BRAF mutation status, patient and tumor characteristics, RFS, and DSS were analyzed. The BRAF mutation was present in 67% of patients. On multivariate analysis, presence of the mutation predicted only for capsular invasion (HR, 1.7; 95% CI, 1.1–2.6), cervical lymph node involvement (HR, 1.7; 95% CI, 1.1–2.7), and classic papillary histology (HR, 1.8; 95% CI 1.1–2.9). There was no significant relationship between the BRAF mutation and RFS or DSS, an observation that was consistent across univariate, multivariate, and Kaplan–Meier analyses. This is the most extensive study to date in the United States to demonstrate that BRAF mutation is of no predictive value for recurrence or survival in PTC. We found correlations of BRAF status and several clinicopathologic characteristics of high‐risk disease, but limited evidence that the mutation correlates with more extensive or aggressive disease. This analysis suggests that BRAF is minimally prognostic in PTC. However, prevalence of the BRAF mutation is 70% in the general population, providing the opportunity for targeted therapy.
Biotechnological Production of Astaxanthin through Metabolic Engineering of Yeasts
Authors: Ye Lidan , Xie Wenping , Zhou Pingping , Yu Hongwei 
Published: February 2015

AbstractAstaxanthin is a highly valued carotenoid with growing market in aquaculture, food, cosmetic and pharmaceutical industries. The market demand for bio‐derived astaxanthin and the insufficient efficiency of astaxanthin biosynthesis drive the advances in metabolic engineering of native astaxanthin producers and heterologous hosts. The recent research progress in engineering of astaxanthin biosynthesis in the red‐pigmented heterobasidiomycetous yeast Xanthophyllomyces dendrorhous, the food‐grade noncarotenogenic yeast Candida utilis, the oleaginous yeast Yarrowia lipolytica and the chassis organism Saccharomyces cerevisiae is reviewed, the advances in the development of pathway engineering tools are discussed, and future strategies for further improving biotechnological production of astaxanthin in yeasts are proposed.