bluuebunny/crossref_metadata_2025_split huggingface dataset:
T1 and T2 values of human neonatal blood at 3 Tesla: Dependence on hematocrit, oxygenation, and temperature
Authors: Liu Peiying , Chalak Lina F. , Krishnamurthy Lisa C. , Mir Imran , Peng Shin‐lei , Huang Hao , Lu Hanzhang 
Published: May 2015

PurposeKnowledge of blood T1 and T2 is of major importance in many applications of MRI in neonates. However, to date, there has not been a systematic study to examine neonatal blood T1/T2 relaxometry. This present study aims to investigate this topic.MethodsUsing freshly collected blood samples from human umbilical cord, we performed in vitro experiments under controlled physiological conditions to measure blood T1 and T2 at 3 Tesla (T) and their dependence on several factors, including hematocrit (Hct), oxygenation (Y) and temperature.ResultsThe arterial T1 in neonates was 1825 ± 184 ms (Hct = 0.42 ± 0.08), longer than that of adult blood. Neonatal blood T1 was strongly dependent on Hct (P < 0.001) and Y (P = 0.005), and the dependence of T1 on Y was more prominent at higher Hct. The arterial T2 of neonatal blood was 191 ms at an Hct of 0.42, which was also longer than adult blood. Neonatal blood T2 was positively associated with blood oxygenation and negatively associated with hematocrit level, and can be characterized by an exchange model. Neonatal blood T1 was also positively associated with temperature (P < 0.001).ConclusionThe values provided in this report may provide important reference and calibration information for sequence optimization and quantification of in vivo neonatal MRI studies. Magn Reson Med 75:1730–1735, 2016. © 2015 Wiley Periodicals, Inc.
Influence of muscle fiber orientation on water and metabolite relaxation times, magnetization transfer, and visibility in human skeletal muscle
Authors: MacMillan Erin Leigh , Bolliger Christine Sandra , Boesch Chris , Kreis Roland 
Published: May 2015

PurposeTo gain a deeper understanding of the influence of skeletal muscle fiber orientation on metabolite visibility, magnetization transfer from water, and water proton relaxation rates in 1H MR spectra.MethodsNon–water‐suppressed MR spectroscopy was performed in tibialis anterior muscle (TA) of 10 healthy adults, with the TA oriented either parallel or at the magic angle to the 3T field. Spectra were acquired with metabolite‐cycled PRESS, and water inversion from 50 to 2510 ms before excitation. Water proton T2 relaxation was sampled with STEAM with echo times from 12 to 272 ms.ResultsApparent concentrations of total creatine (tCr), taurine, and trimethylammonium compounds were reduced by 29% to 67% when TA was parallel to B0. Both tCr peak areas were strongly correlated to the methylene peak splitting. Magnetization transfer rates from water to tCr CH3 were not significantly different between orientations. Water T1s were similar between orientations, but T2s were statistically significantly shorter by 1 ms in the parallel orientation (P = 0.002).ConclusionMuscle metabolite visibilities in MR spectroscopy and water T2 times depend substantially on muscle fiber orientation relative to B0. In contrast, magnetization transfer rates appear to depend on muscle composition, rather than fiber orientation. Magn Reson Med 75:1764–1770, 2016. © 2015 Wiley Periodicals, Inc.
Modelling and performance analysis of application‐aware resource management
Authors: Wamser Florian , Blenk Andreas , Seufert Michael , Zinner Thomas , Kellerer Wolfgang , Tran‐Gia Phuoc 
Published: May 2015

SummaryApplication‐aware resource management is the approach to tailor access networks to have characteristics beneficial for the running applications and services. This is achieved through the monitoring and integration of key performance indicators from the application layer within the network resource management. The aim is to increase user‐perceived quality and network resource efficiency by traffic engineering with the help of these indicators. Using analytic and simulative approaches, this paper provides analysis methods for network operators to quantify the performance gains of alternative resource allocation algorithms that implement the application‐aware concept. Network operators can use the proposed methods to evaluate possible performance gain trade‐offs between investing in a pure capacity increase (over‐provisioning) and the realization of an application‐aware resource allocation. For this purpose, we model and analyse the application quality trade‐offs of four algorithms for application‐aware resource management at a single link in varying traffic situations. The algorithms are chosen with respect to different complexity and implementation level in order to cover the design space in a systematic way. The study of the algorithms focuses on the application‐layer performance for the most used applications today, namely, web browsing and video streaming with constant bit rate as well as hypertext transfer protocol progressive streaming with variable bit rate. Application quality trade‐offs are analysed in particular for a high‐resource utilization at a bottleneck link. The results confirm that application‐aware resource management outperforms best‐effort resource management in terms of quality of experience. Moreover, our study provides guidelines for the selection and configuration of the evaluated algorithms. Copyright © 2015 John Wiley & Sons, Ltd.
Recent Advances and Future Directions for Quality Engineering
Authors: Vining Geoff , Kulahci Murat , Pedersen Søren 
Published: May 2015

The origins of quality engineering are in manufacturing, where quality engineers apply basic statistical methodologies to improve the quality and productivity of products and processes. In the past decade, people have discovered that these methodologies are effective for improving almost any type of system or process, such as financial, health care, and supply chains.This paper begins with a review of key advances and trends within quality engineering over the past decade. The second part uses the first part as a foundation to outline new application areas for the field. It also discusses how quality engineering needs to evolve in order to make significant contributions to these new areas. © 2015 The Authors Quality and Reliability Engineering International Published by John Wiley & Sons Ltd.
Optimized Karatsuba squaring on 8‐bit AVR processors
Authors: Seo Hwajeong , Liu Zhe , Choi Jongseok , Kim Howon 
Published: May 2015

AbstractMulti‐precision squaring is one of the performance‐critical operations for implementation of elliptic curve cryptography. This paper continues the line of research on high‐speed multi‐precision squaring on embedded processors. In particular, we present an optimized Karatsuba squaring method for 8‐bit AVR processors. We compute the multiplication part with the fastest Karatsuba multiplication, and then the remaining two squaring parts are conducted with the fastest sliding block doubling squaring. As a result, The proposed method sets the new speed records for multi‐precision squaring, improving the execution time by up to 8.49% compared with the best known works. Copyright © 2015 John Wiley & Sons, Ltd.
Thinking about U: Theorizing and testing U‐ and inverted U‐shaped relationships in strategy research
Authors: Haans Richard F. J. , Pieters Constant , He Zi‐Lin 
Published: May 2015

Research summary:U‐ and inverted U‐shaped relationships are increasingly explored in strategy research, with 11 percent of all articles published in Strategic Management Journal (SMJ) in 2008–2012 investigating such quadratic relationships. Moreover, a movement towards introducing moderation to quadratic relationships has emerged. By reviewing 110 articles published in SMJ from 1980 to 2012, we identify several critical issues in theorizing and testing of these relationships for which current practice falls short. These include insufficient causal argumentation, incorrect testing, mixing up two different types of moderation, and not realizing that the curve can flip completely. For these and other issues, a guideline is provided which, when followed, may bring clarity to theoretical motivation and rigor to empirical testing.Managerial summary:Too much can be as bad as too little. Many relationships in strategic management follow an inverted U‐shaped pattern, where moderate levels of a strategy lead to optimal performance. To gain deeper insights into the conventional wisdom that too much of a good thing can be harmful to performance, we discuss how such relationships can be better theorized and tested based on a review of articles exploring U‐shaped relationships in Strategic Management Journal during 1980–2012. We identify several critical issues that require close attention and provide a guideline to further develop and validate this important managerial intuition. Copyright © 2015 John Wiley & Sons, Ltd.
An Architectural Approach to Requirements Engineering for Infrastructure Projects
Authors: Silmon Joe , Evans Rhianne , Brownsword Mike , Nicholson David 
Published: May 2015

ABSTRACTA brand‐new high‐speed railway project such as HS2, currently under development in the United Kingdom, presents a requirements engineering problem that is similar to domains where Systems Engineering (SE) is more traditionally applied, such as an aircraft, but with some differences in system structure that preclude a direct mapping of routine techniques. With over 300 separate elements of design in the Country South portion of the route, fitting into roughly 20 categories and inheriting requirements at multiple levels, including location‐specific constraints, it was considered necessary to implement a model‐based solution to provide an adequate level of technical assurance by managing the requirements and their links to the design elements. A database tool with diagramming capability was used to create a visual traceability structure between the client's original requirements and the refined requirements. A layered model of the system architecture was used to apply requirements to the correct sets of individual design elements. From this combined requirements and architecture model, spreadsheet checklists were generated for designers to perform verification. The resulting data were then re‐imported to the database and processed into a detailed report for submission to the client. The solution developed automates assignment of requirements traceability in order to provide exactly the right set of requirements for each deliverable on the route, which may consist of multiple asset types in differing combinations and with local requirements as well as more generic requirements assigned by equivalence.
Incentive‐Based Negotiation Model for System of Systems Acquisition
Authors: Kilicay‐Ergin Nil , Dagli Cihan 
Published: May 2015

ABSTRACTLack of collaboration between individual systems and system of systems (SoS) program management is identified as one of the leading problems in SoS acquisition. This is especially a major concern in acknowledged SoS where a designated SoS program management has no authority over the constituent systems. Therefore, it is important to consider mechanisms to persuade individual systems to participate in the SoS development. In SoS where individual systems have their own self‐interests, negotiation becomes an important mechanism to increase participation in SoS development. Another mechanism, incentives, is used in a wide range of applications to improve performance and collaboration. In this paper, an incentive based negotiation model is outlined as a mechanism to increase participation of individual systems into the SoS development. The negotiation model is integrated into an SoS Engineering and Architecting multilevel model referred to as Flexible & Intelligent Learning Architectures for SoS (FILA‐SoS). Various aspects of SoS acquisition are modeled in the FILA‐SoS including SoS meta‐architecture generation, evaluation as well as negotiation between SoS and individual systems. Individual systems exhibit behaviors, ranging from selfish to cooperative. The negotiation model is demonstrated on an SoS engineering application: Intelligence, Surveillance, and Reconnaissance (ISR) SoS acquisition case where a desired meta‐architecture is selected for negotiation, and incentives are determined for systems based on deviation from the desired meta‐architecture quality. The analyses of the results from this application domain provide insights into how incentives can be used by decision makers to increase participation in SoS engineering and development.
Fetal umbilical–portal–systemic venous shunt: in‐utero classification and clinical significance
Authors: Achiron R. , Kivilevitch Z. 
Published: May 2015

ABSTRACTObjectivesTo review our experience with fetal umbilical–portal–systemic venous shunts (UPSVS), to devise an in‐utero classification system, and to analyze their clinical and prognostic characteristics.MethodsThis was a retrospective review of cases of UPSVS examined at an academic tertiary referral center over the 14‐year period from 2001 to 2014 inclusive. The anatomical origin and drainage of the fetal umbilical, portal, ductus venosus and hepatic venous systems, and the integrity of the intrahepatic portal venous system (IHPVS), were assessed using two‐ and three‐dimensional color Doppler sonography. Fetomaternal clinical characteristics and long‐term outcome were investigated by means of medical files, imaging documentation and telephone interviews with the mothers.ResultsForty‐four cases with UPSVS were reviewed. Prenatal classification was based on the anatomical origin of the shunt (umbilical, portal or ductal), with cases classified into four types: Type I, umbilical–systemic shunt (n = 9 (20.4%)); Type II, ductus venosus–systemic shunt (n = 19 (43.2%)); and Type III, portal–systemic shunt, divided into two subtypes: Type IIIa, intrahepatic portal–systemic shunt (n = 12 (27.2%)) and Type IIIb, extrahepatic portal–systemic shunt (n = 4 (9.1%)). Each type presented particular clinical and prognostic characteristics. The most important favorable prognostic factors were absence of associated major malformation and presence of the IHPVS. Thus, Type IIIa (intrahepatic portal–systemic shunt) had the best outcome.ConclusionsFetal UPSVS are anomalies with a broad spectrum of manifestations and prognoses. Accurate mapping of the IHPVS is paramount for optimizing prenatal counseling and postnatal care. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
The activation strain model and molecular orbital theory
Authors: Wolters Lando P. , Bickelhaupt F. Matthias 
Published: May 2015

The activation strain model is a powerful tool for understanding reactivity, or inertness, of molecular species. This is done by relating the relative energy of a molecular complex along the reaction energy profile to the structural rigidity of the reactants and the strength of their mutual interactions: ΔE(ζ) = ΔEstrain(ζ) + ΔEint(ζ). We provide a detailed discussion of the model, and elaborate on its strong connection with molecular orbital theory. Using these approaches, a causal relationship is revealed between the properties of the reactants and their reactivity, e.g., reaction barriers and plausible reaction mechanisms. This methodology may reveal intriguing parallels between completely different types of chemical transformations. Thus, the activation strain model constitutes a unifying framework that furthers the development of cross‐disciplinary concepts throughout various fields of chemistry. We illustrate the activation strain model in action with selected examples from literature. These examples demonstrate how the methodology is applied to different research questions, how results are interpreted, and how insights into one chemical phenomenon can lead to an improved understanding of another, seemingly completely different chemical process. WIREs Comput Mol Sci 2015, 5:324–343. doi: 10.1002/wcms.1221This article is categorized under:

Structure and Mechanism > Molecular Structures
Propofol administration in patients with methylmalonic acidemia and intracellular cobalamin metabolism disorders: a review of theoretical concerns and clinical experiences in 28 patients
Authors: Ktena Yiouli P. , Ramstad Trygg , Baker Eva H. , Sloan Jennifer L. , Mannes Andrew J. , Manoli Irini , Venditti Charles P. 
Published: May 2015

AbstractBackgroundMethylmalonic acidemia and intracellular cobalamin metabolism disorders represent a heterogeneous group of inborn errors of metabolism. Most patients will require diagnostic and/or therapeutic procedures frequently requiring sedation or anesthetic management due to neurological and neurocognitive impairments. It has been stated that propofol is contraindicated in this population. We report our experience with propofol administration in a large series of patients.MethodsTwenty eight patients (14 mut, seven cblC, three cblA, three cblB, one cblG) aged 2–35.6 years enrolled in a natural history study (ClinicalTrials.gov identifier: NCT00078078) and required anesthetics for 39 diagnostic or therapeutic procedures. Data were collected on the anesthetic technique, perianesthetic course, and adverse events related to propofol.ResultsPropofol was used as the sole induction agent in most cases (36/39) and as the primary maintenance agent in all cases. Infusion rates were 100–400 mcg kg−1 min−1 (mean = 214). Infusion duration was 60–325 min (mean = 158) and total doses ranged between 270–3610 mg (mean = 1217). Adverse events were recorded in two cases; neither appeared to be related to propofol administration.ConclusionsPropofol is an effective, safe induction and maintenance agent for elective short procedures requiring anesthesia in patients with MMA and cobalamin metabolism disorders. Despite multiple comorbidities and propensity toward instability, those affected can receive anesthesia with an acceptable safety profile, if metabolically and hemodynamically stabilized prior to the event.SynopsisA review of the perianesthetic records of 28 patients with isolated MMA and intracellular cobalamin metabolism disorders suggests that propofol anesthesia can be administered safely to these patients, in the setting of metabolic stability.
Use of 2H and 18O stable isotopes to investigate water sources for different ages of Populus euphratica along the lower Heihe River
Authors: Liu Shubao , Chen Yaning , Chen Yapeng , Friedman Jonathan M. , Hati Jarre Heng A. , Fang Gonghuan 
Published: May 2015

AbstractInvestigation of the water sources used by trees of different ages is essential to formulate a conservation strategy for the riparian tree, P. euphratica. This study addressed the contributions of different potential water sources to P. euphratica based on levels of stable oxygen and hydrogen isotopes (δ18O, δ2H) in the xylem of different aged P. euphratica, as well as in soil water and groundwater along the lower Heihe River. We found significant differences in δ18O values in the xylem of different aged P. euphratica. Specifically, the δ18O values of young, mature and over‐mature forests were −5.368(±0.252) ‰, −6.033(± 0.185) ‰ and −6.924 (± 0.166) ‰, respectively, reflecting the reliance of older trees on deeper sources of water with a δ18O value closer to that of groundwater. Different aged P. euphratica used different water sources, with young forests rarely using groundwater (mean <15 %) and instead primarily relying on soil water from a depth of 0–50 cm (mean >45 %), and mature and over‐mature forests using water from deeper than 100 cm derived primarily from groundwater.
Differentiation of regioisomeric chloroamphetamine analogs using gas chromatography–chemical ionization-tandem mass spectrometry
Authors: Negishi Shoko , Nakazono Yukiko , Iwata Yuko T. , Kanamori Tatsuyuki , Tsujikawa Kenji , Kuwayama Kenji , Yamamuro Tadashi , Miyamoto Kazuna , Yamashita Takuya , Kasuya Fumiyo , Inoue Hiroyuki 
Published: May 2015

Abstract
In recent years, a large number of clandestinely synthesized new psychoactive substances with high structural variety have been detected in forensic samples. Analytical differentiation of regioisomers is a significant issue in forensic drug analysis, because, in most cases, legal controls are placed on only one or two of the conceivable isomers. In this study, gas chromatography–tandem mass spectrometry (GC–MS–MS) was used to differentiate the regioisomers of chloroamphetamine analogs (chloroamphetamines and chloromethamphetamines) synthesized in the authors′ laboratories. Free bases, trifluoroacetyl derivatives, and trimethylsilyl derivatives were subjected to GC–MS–MS using DB-1ms, DB-5ms, and DB-17ms capillary columns, respectively. The regioisomers of chloroamphetamine analogs in all forms were well separated on the DB-5ms column. The electron ionization mass spectra of the chloroamphetamine analogs gave very little structural information for differentiation among these analogs, even after trifluoroacetyl and trimethylsilyl derivatization of the analytes. Characteristic product ions of the 2-positional isomers were observed by electron ionization-MS–MS. In contrast, chemical ionization-MS–MS of the free bases provided more structural information about chloride position on the aromatic ring when [M+H–HCl]+ was selected as a precursor ion. The results suggest that a combination of chromatographic analysis and MS–MS supports differentiation for regioisomers of chloroamphetamine analogs.
A case of primary ciliary dyskinesia treated with ICSI using testicular spermatozoa: case report and a review of the literature
Authors: Kawasaki Akiko , Okamoto Hajime , Wada Atsushi , Ainoya Yoko , Kita Naoki , Maeyama Tetsuro , Edamoto Naoko , Nishiyama Hiroyuki , Tsukamoto Sadamu , Joraku Akira , Waku Natsui , Yoshikawa Hiroyuki 
Published: May 2015

AbstractPurposeTo investigate whether or not intracytoplasmic sperm injection (ICSI) using spermatozoa extracted from testis (TESE‐ICSI) is a more effective treatment than ICSI with ejaculated spermatozoa (EJ‐ICSI) for primary ciliary dyskinesia (PCD).MethodsWe reported a case of PCD in which we performed TESE‐ICSI after repeated failure of EJ‐ICSI. Together with data from previous case reports, we compared the fertilization rate and pregnancy outcome of TESE‐ICSI and EJ‐ICSI.ResultsIn our case, TESE‐ICSI improved the morphology of spermatozoa and fertilization rate. However, the outcome was only a biochemical pregnancy. According to the analysis combined with previous reports, there was no difference in the fertilization rate and pregnancy outcome parameters between TESE‐ICSI and EJ‐ICSI.ConclusionsTESE‐ICSI for PCD may improve the fertilization rate compared to EJ‐ICSI. However, it does not necessarily improve the pregnancy outcome for a patient with primary ciliary dyskinesia.