bluuebunny/crossref_metadata_2025 huggingface dataset:
Sigilo telefônico nas constituições de brasil e portugal: análise do tratamento da medida na lei e na jurisprudencial e o limite entre proteção deficiente e eficiente
Authors: Santos Diego Prezzi , Amaral Antonio José Mattos do
Published: May 2016

O presente estudo busca analisar os requisitos de interceptações telefônicas no Brasil e em Portugal, pautando a análise em normas constitucionais e normas infraconstitucionais. A análise passa pela compreensão dos direitos vinculados à intimidade da pessoa e a vida privada e da possibilidade que tem o investigado, alvo da quebra de sigilo telefônico através de interceptação telefônica, de ter garantido o acesso material à justiça, tendo, para tanto, respeitados estes direitos. Fora verificado o conceito de acesso à ordem jurídica justa (material) e também o acesso formal para que fosse possível a compreensão e apresentação dos resultados obtidos junto aos tribunais brasileiros e aos tribunais portugueses.
Environmental Conditions, Entrepreneur Alertness and Social Capital on Performance
Authors: Lin Yu-Li , Liu Hsiu-Wen , Xu Fengzeng , Wang Hao
Published: May 2016

This study addresses the important question of causal complexity as it relates to the influence of social capital, entrepreneurial alertness and the entrepreneurship environment on business performance. Using a relatively new methodological approach, namely fuzzy-set qualitative comparative analysis (fsQCA), this paper aims to investigate alternative complex antecedent conditions (or causal recipes) that lead to high performance. Based on a survey of 194 entrepreneurs in China, this paper shows that business performance is likely to be the result of a combination of causal factors. This study finds that: (1) four different configurations of social capital, entrepreneurial alertness and entrepreneurship environment were “equifinal” causes of high performance, and (2) market openness should fit other environmental conditions to achieve high performance. This study contributes to research on entrepreneurship by applying the ideas of “equifinality” and “fit” to entrepreneurial characteristics and environment theory.
The Influence of Electronic Dictionaries on Vocabulary Knowledge Extension
Authors: Rezaei Mojtaba , Davoudi Mohammad
Published: May 2016

Vocabulary learning needs special strategies in language learning process. The use of dictionaries is a great help in vocabulary learning and nowadays the emergence of electronic dictionaries has added a new and valuable resource for vocabulary learning. The present study aims to explore the influence of Electronic Dictionaries (ED) Vs. Paper Dictionaries (PD) on vocabulary learning and retention of Iranian EFL learners. Seventy college students formed the participants of the study. Before the treatment, a Preliminary English Test was used for assessing the participants’ homogeneity. The participants were assigned to Electronic Dictionary (ED) group and Paper Dictionary (PD) group. The treatment lasted for 15 sessions. Eighty-eight new target words were selected in order to be taught in this study. The ED group participants were asked to use their mobile dictionary (Blue Dict dictionary), that include eight popular different dictionaries. The participants of the PD group used their ordinary Paper Dictionaries for finding the meaning of words. In order to check their short-term and long-term vocabulary learning, both groups took part in an immediate and delayed post-test respectively after the treatment. Based on the t-test results, the participants in ED group outperformed those of PD group. The overall results indicate that EDs can improve vocabulary learning.
Effect of Blanching on Saponins and Nutritional Content of Moringa Leaves Extract
Authors: Indriasari Yuanita , Wignyanto Wignyanto , Kumalaningsih Sri
Published: May 2016

Moringa oleifera leaves have been used as food material because it has high nutritional value. Many research have been conducted on moringa leaves extract as functional food and the additional material of nutrient for some food products (biscuit, bread, jelly drink), which it looked that adding moringa leaves extract above 5% decrease the consumer acceptance level toward the product because of the strongest unpleasant aroma and bitter taste, which is caused by saponins content in moringa leaves extract is still high enough. The aim of the research is to determine the optimum time and temperature of blanching process of moringa leaves in order to decrease its saponin content and at the same time to preserve its nutritional content. Blanching process used temperature 85 ˚C for 7.5 minutes can decrease saponins content of moringa leaves to the lowest content amount 3.9 %, but still preserve protein content amount 25.08 %, vitamin C content amount 84.68 mg 100g-1 and increase vitamin A amount 3600 μg 100g-1.
Frozen and Untouchable
Authors: Etheredge Francis ,   The National Catholic Bioethics Center
Published: May 2016

The ethical limbo in which frozen human embryos exist is, tragically, a real limbo, and in their untouchability lies an apparent contradiction: that God cannot rescue a person whom man, in his pride, has co-created outside the truly necessary incorporation within a family. The author explores the possibility that ethical objections to embryo adoption are based on a flawed conflation of two problems: (1) the immorality, injustice, and harm of the procedure that supplants the marriage act; and (2) the rights of the child conceived outside the welcoming nature of the marriage act—the primary rights of every conceived person to completing, wholesome, and relational nurture. The author argues for the humanitarian right to embryo adoption, within marriage, from the point of view of the rights of the person conceived.
Marriage, “Bodily Union,” and Natural Teleology
Authors: Madden Joshua ,   The National Catholic Bioethics Center
Published: May 2016

In recent years the account of natural law that has come to be known as the “new natural law theory” has come under criticism. Rebekah Johnston has engaged quite seriously with the NNL account of marriage and sexuality and has deemed it insufficient and internally inconsistent, going so far as to argue for the legitimacy of homosexual “marriage” based on the NNL’s own system. The author argues in this essay that the NNL does not fully realize the implications of its position in this regard, and that Rebekah Johnston’s critique fails similarly in providing an account of marriage and sexuality. To remedy these errors, the role of normative, natural teleology must be investigated thoroughly.
The Neurofilament-Derived Peptide NFL-TBS.40-63 Targets Neural Stem Cells and Affects Their Properties
Authors: Lépinoux-Chambaud Claire , Barreau Kristell , Eyer Joël
Published: May 2016

Targeting neural stem cells (NSCs) in the adult brain represents a promising approach for developing new regenerative strategies, because these cells can proliferate, self-renew, and differentiate into new neurons, astrocytes, and oligodendrocytes. Previous work showed that the NFL-TBS.40-63 peptide, corresponding to the sequence of a tubulin-binding site on neurofilaments, can target glioblastoma cells, where it disrupts their microtubules and inhibits their proliferation. We show that this peptide targets NSCs in vitro and in vivo when injected into the cerebrospinal fluid. Although neurosphere formation was not altered by the peptide, the NSC self-renewal capacity and proliferation were reduced and were associated with increased adhesion and differentiation. These results indicate that the NFL-TBS.40-63 peptide represents a new molecular tool to target NSCs to develop new strategies for regenerative medicine and the treatment of brain tumors.

Significance

In the present study, the NFL-TBS.40-63 peptide targeted neural stem cells in vitro when isolated from the subventricular zone and in vivo when injected into the cerebrospinal fluid present in the lateral ventricle. The in vitro formation of neurospheres was not altered by the peptide; however, at a high concentration of the peptide, the neural stem cell (NSC) self-renewal capacity and proliferation were reduced and associated with increased adhesion and differentiation. These results indicate that the NFL-TBS.40-63 peptide represents a new molecular tool to target NSCs to develop new strategies for regenerative medicine and the treatment of brain tumors.
Functional Plasticity of Adipose-Derived Stromal Cells During Development of Obesity
Authors: Zhu Xiang-Yang , Ma Shuangtao , Eirin Alfonso , Woollard John R. , Hickson LaTonya J. , Sun Dong , Lerman Amir , Lerman Lilach O.
Published: May 2016

Obesity is a major risk factor for a number of chronic diseases, including diabetes, cardiovascular diseases, and cancer. Expansion of the adipose mass requires adipocyte precursor cells that originate from multipotent adipose-derived stromal cells (ASCs), which in turn also participate in repair activities. ASC function might decline in a disease milieu, but it remains unclear whether ASC function varies during the development of obesity. We tested the hypothesis that microenvironmental inflammatory changes during development of metabolic disorders in obesity affect ASC function. Domestic pigs were fed with an atherogenic (n = 7) or normal (n = 7) diet for 16 weeks. Abdominal adipose tissue biopsies were collected after 8, 12, and 16 weeks of diet for ASC isolation and immunohistochemistry of in situ ASCs and tumor necrosis factor-α (TNF-α). Longitudinal changes in proliferation, differentiation, and anti-inflammatory functions of ASCs were assessed. At 16 weeks, upregulated TNF-α expression in adipose tissue from obese pigs was accompanied by increased numbers of adipocyte progenitors (CD24+/CD34+) in adipose tissue and enlarged adipocyte size. In vitro, ASCs from obese pigs showed enhanced adipogenic and osteogenic propensity, which was abolished by anti-TNF-α treatment, whereas lean ASCs treated with TNF-α showed enhanced adipogenesis. Furthermore, obese ASCs showed increased senescence compared with lean ASCs, whereas their immunomodulatory capacity was preserved. Adipose tissue inflammation promotes an increase in resident adipocyte progenitors and upregulated TNF-α enhances ASC adipogenesis. Thus, adipose tissue anti-inflammatory strategies might be a novel target to attenuate obesity and its complications.

Significance

Adipose-derived stromal cell (ASC) function might decline in a disease milieu, but it remains unclear whether ASC function varies during the development of obesity. This study tested the hypothesis that microenvironmental inflammatory changes during development of metabolic disorders in obesity affect ASC function. It was found that ASCs show increased propensity for differentiation into adipocytes, which is partly mediated by upregulated tumor necrosis factor-α (TNF-α), likely in their adipose tissue microenvironment. Furthermore, TNF-α magnified obese ASC senescence, although it did not regulate their anti-inflammatory properties. Thus, adipose tissue inflammation might be a novel therapeutic target to avert ASC maldifferentiation and senescence.
Rapid Induction of Cerebral Organoids From Human Induced Pluripotent Stem Cells Using a Chemically Defined Hydrogel and Defined Cell Culture Medium
Authors: Lindborg Beth A. , Brekke John H. , Vegoe Amanda L. , Ulrich Connor B. , Haider Kerri T. , Subramaniam Sandhya , Venhuizen Scott L. , Eide Cindy R. , Orchard Paul J. , Chen Weili , Wang Qi , Pelaez Francisco , Scott Carolyn M. , Kokkoli Efrosini , Keirstead Susan A. , Dutton James R. , Tolar Jakub , O'Brien Timothy D.
Published: May 2016

Tissue organoids are a promising technology that may accelerate development of the societal and NIH mandate for precision medicine. Here we describe a robust and simple method for generating cerebral organoids (cOrgs) from human pluripotent stem cells by using a chemically defined hydrogel material and chemically defined culture medium. By using no additional neural induction components, cOrgs appeared on the hydrogel surface within 10–14 days, and under static culture conditions, they attained sizes up to 3 mm in greatest dimension by day 28. Histologically, the organoids showed neural rosette and neural tube-like structures and evidence of early corticogenesis. Immunostaining and quantitative reverse-transcription polymerase chain reaction demonstrated protein and gene expression representative of forebrain, midbrain, and hindbrain development. Physiologic studies showed responses to glutamate and depolarization in many cells, consistent with neural behavior. The method of cerebral organoid generation described here facilitates access to this technology, enables scalable applications, and provides a potential pathway to translational applications where defined components are desirable.

Significance

Tissue organoids are a promising technology with many potential applications, such as pharmaceutical screens and development of in vitro disease models, particularly for human polygenic conditions where animal models are insufficient. This work describes a robust and simple method for generating cerebral organoids from human induced pluripotent stem cells by using a chemically defined hydrogel material and chemically defined culture medium. This method, by virtue of its simplicity and use of defined materials, greatly facilitates access to cerebral organoid technology, enables scalable applications, and provides a potential pathway to translational applications where defined components are desirable.
Missionaries, merchants, and Inuit entrepreneurs: An examination of trade relations along the Labrador coast
Authors: Fay Amelia
Published: May 2016

The study of Inuit-European contact in Labrador has often divided the coast into north and south, creating a dichotomy that ignores Inuit mobility and emphasizes the arrival and placement of Europeans along the coast. This has caused some researchers to focus too heavily on missionary trade involvement in the north while ignoring merchant activity in the south, and vice versa. This paper seeks to provide further evidence in support of Inuit entrepreneurs as catalysts for the abundance and diversity of European-made trade goods along the coast, rather than the missionaries or merchants themselves. This study presents an analysis of four Inuit dwellings dating from the mid-18th through early 19th centuries, both pre- and post- missionary arrival, from two distinct regions: Nain and Hamilton Inlet. The results show no significant difference in the quantity of trade goods between the two regions, either before or after the arrival of Moravian missionaries. There may have been another factor at work: influential Inuit traders who were a key component of the trade network, who likely rose to entrepreneurial status prior to the arrival of missionaries, and who continued to move items along the coast thereafter. Thus, the increasing European presence did not largely affect the trade network that had emerged by the early 18th century, aside from providing the Inuit population with access to additional resources and more options.
Intermédiaire d’intermédiaires
Authors: Desmazières1 Albert
Published: May 2016

Le champ de la sécurité connaît actuellement un développement exponentiel du secteur privé, générant de nouveaux modes de gouvernance hybrides basés sur des partenariats public-privé (PPP). Cette recherche propose d’étudier un dispositif sécuritaire spécifique cherchant à combattre une forme de l’objet particulier qu’est le crime en col blanc, c’est-à-dire la lutte anticontrefaçon (LAC) en Belgique, à travers l’analyse complète de ses pratiques de gouvernance, en tentant de trouver des explications à l’impunité relative caractérisant le phénomène criminel. Pour ce faire, une observation participante a été réalisée au sein du Bureau d’investigations privées (le BIP), possédant une place stratégique dans la lutte, et les données recueillies ont été analysées à la lumière de la classification triple des questions de sécurité de Valverde (2011). Il en ressort que l’impunité émanant du dispositif de la LAC, tiraillé par des logiques contradictoires d’application de la loi et de rentabilisation économique, n’est pas à imputer à un manque de collaboration au sein du PPP, le BIP s’appliquant à la garantir. Le dispositif apparaissant paradoxalement stable, l’impunité serait davantage le produit d’une définition des priorités, fréquente lorsqu’il s’agit de crime en col blanc, de la part des acteurs aux commandes : les magistrats et les marques.
Quand les corps adolescents parlent de l’enfermement
Authors: Jaspart1 Alice
Published: May 2016

L’article propose d’entrer dans l’enfermement des jeunes garçons contrevenants en Belgique, en s’intéressant aux corps des adolescents et à leurs expériences sensorielles. C’est éclairée par la littérature traitant du corps des détenus en prison pour adultes, et plus particulièrement du corps comme « site de contrôle » et « site de résistance » (Frigon, 2012), que nous proposons de (ré)explorer un matériau ethnographique récolté dans quatre institutions fermées pour jeunes garçons. Après avoir situé le propos au regard des institutions concernées et de la méthodologie adoptée, nous suivrons les corps en mutation qui grandissent ou sont arrêtés dans leur croissance dans l’enfermement pour interroger les marques institutionnelles ainsi que les dynamiques de défense corporelle que l’on peut y déceler.
The impact of HIV infection on blood leukocyte responsiveness to bacterial stimulation in asymptomatic patients and patients with bloodstream infection
Authors: Huson Michaëla A M , Hoogendijk Arie J , de Vos Alex F , Grobusch Martin P , van der Poll Tom
Published: May 2016

Introduction

HIV‐induced changes in cytokine responses to bacteria may influence susceptibility to bacterial infections and the consequent inflammatory response.

Methods

We examined the impact of HIV on whole blood responsiveness to bacterial stimulation in asymptomatic subjects and patients with bacterial bloodstream infection (BSI). Whole blood was stimulated ex vivo with two bacterial Toll‐like receptor agonists (lipopolysaccharide and lipoteichoic acid) and two pathogens (Streptococcus pneumoniae and non‐typhoidal Salmonella), which are relevant in HIV‐positive patients. Production of interferon‐γ, tumour necrosis factor‐α, interleukin‐1β and interleukin‐6 was used as a read‐out.

Results

In asymptomatic subjects, HIV infection was associated with reduced interferon‐γ, release after stimulation and priming of the pro‐inflammatory cytokine response to non‐typhoidal Salmonella. In patients with BSI, we found no such priming effect, nor was there evidence for more profound sepsis‐induced immunosuppression in BSI patients with HIV co‐infection.

Conclusions

These results suggest a complex effect of HIV on leukocyte responses to bacteria. However, in patients with sepsis, leukocyte responses were equally blunted in patients with and without HIV infection.
Two-way communication between SecY and SecA suggests a Brownian ratchet mechanism for protein translocation
Authors: Allen William John , Corey Robin Adam , Oatley Peter , Sessions Richard Barry , Baldwin Steve A , Radford Sheena E , Tuma Roman , Collinson Ian
Published: May 2016

The essential process of protein secretion is achieved by the ubiquitous Sec machinery. In prokaryotes, the drive for translocation comes from ATP hydrolysis by the cytosolic motor-protein SecA, in concert with the proton motive force (PMF). However, the mechanism through which ATP hydrolysis by SecA is coupled to directional movement through SecYEG is unclear. Here, we combine all-atom molecular dynamics (MD) simulations with single molecule FRET and biochemical assays. We show that ATP binding by SecA causes opening of the SecY-channel at long range, while substrates at the SecY-channel entrance feed back to regulate nucleotide exchange by SecA. This two-way communication suggests a new, unifying 'Brownian ratchet' mechanism, whereby ATP binding and hydrolysis bias the direction of polypeptide diffusion. The model represents a solution to the problem of transporting inherently variable substrates such as polypeptides, and may underlie mechanisms of other motors that translocate proteins and nucleic acids.
Leaky‐Wave Antennas
Authors: Galli Alessandro , Baccarelli Paolo , Burghignoli Paolo
Published: May 2016

Leaky‐wave antennas (LWAs) represent a class of radiators whose features can efficiently be described in terms of an electromagnetic traveling wave with complex wavenumber (leaky wave) able to propagate in guiding structures that do not completely confine the field. These guiding structures allow for a gradual loss of power to the external environment (leakage). In this article, in conjunction with the fundamental operating principles, the distinctive features of LWAs are described in terms of types and relevant radiation patterns. The basic analysis and the design techniques are summarized, and the main configurations are reviewed, emphasizing historical developments as well as new trends of such radiating elements.
Cooperative Positioning in Wireless Networks
Authors: Gholami Mohammad Reza , Keskin Musa Furkan , Gezici Sinan , Jansson Magnus
Published: May 2016

In this article, we study cooperative positioning in wireless networks in which target nodes at unknown locations locally collaborate with each other to find their locations. We review different models available for positioning and categorize the model‐based algorithms in two groups: centralized and distributed. We then investigate a lower bound on the variance of unbiased estimators, namely the Cramer–Rao lower bound, which is a common benchmark in the positioning literature. We finally discuss some open problems and research topics in the area of positioning that are worth exploring in future studies.
Inductive Power Transmission Systems
Authors: Kiani Mehdi , Ghovanloo Maysam
Published: May 2016

Powering up and recharging a variety of mobile devices, such as implantable medical devices (IMD), smartphones, and electric vehicles, are governed by the same fundamental principles of near‐field inductive coupling, which guide the design constraints and practical considerations of inductive power transmission described in this article. The coupling coefficient and power transmission efficiency (PTE) of an inductive link, which are affected by important geometrical and circuit design parameters on both transmitter (Tx) and receiver (Rx) sides, are discussed. The inductive link PTE has been modeled based on the reflected load theory, indicating that the mutual coupling between the coils has the most significant effect on the PTE, followed by the primary and secondary coils' quality factors. To these factors, one should add the load resistance, source resistance, carrier frequency, and the surrounding environment. Three and four‐coil inductive links have been utilized as a way to achieve optimal loading condition and to reduce the negative effect of load/source resistances on the PTE. This article also includes an optimization method for the wireless links that are made of printed spiral coils (PSC), which are suitable for IMDs and radio‐frequency identification (RFID) applications.
Ocular and Periocular Biometrics
Authors: Jillela Raghavender , Ross Arun
Published: May 2016

Several ocular modalities have been proven to serve as biometric indicators. Among all ocular traits, iris is considered to provide highly reliable recognition performance. However, several challenges exist in iris recognition under uncontrolled scenarios. In such situations, periocular information could be of benefit due to its ease of acquisition and matching. The goal of this chapter is to provide an overview of periocular recognition and the progress made over the past few years. Other ocular biometric traits such as retina, iris, and conjunctival vasculature are also discussed.
Ferroelectric Antenna Technology
Authors: Miranda Félix A. , Romanofsky Robert R.
Published: May 2016

Ferroelectrics represent a broad class of materials exhibiting spontaneous polarization that can be controlled by application of an external dc electric field. Many crystal families support ferroelectricity, but for microwave device and circuit applications, attention has been focused on perovskites, and especially barium strontium titanate. Since the polarization and hence dielectric constant can be modified, frequency‐ and phase‐agile microwave components can be realized. This article focuses on microwave antenna applications, including tunable antennas, phase shifters, and scanning antennas based on both bulk and thin film materials.
Electromagnetic Radiation Physics: Demonstrations Using Free Charge and Simple Wire Objects
Authors: Miller E. K.
Published: May 2016

Electromagnetic radiation is discussed from the analytical perspective that charge acceleration is necessary to produce an electromagnetic field that falls off distance with R as 1/R from a radiating source. The discussion begins with the Lienard–Wiechert potentials that show a radiation field is proportional to charge acceleration. A graphical construction known as theE‐field kink model is discussed as a second way to illustrate the connection between charge acceleration and radiation. A generic wire object is introduced as a means to demonstrate the various ways that charge acceleration and subsequent radiation will occur. These features include exciting sources; wire‐radius discontinuities; impedance loads; wire bends; wire curvature; open ends; and straight‐wire sections. Each of these is explored in various levels of detail in the discussion that follows, which are illustrated with numerous computed examples using the frequency‐domain model NEC (Numerical Electromagnetics Code) and the time‐domain model TWTD (thin‐wire time domain). A technique called FARS (far‐field analysis of radiation sources) is also introduced as a means of showing quantitatively where radiation originates from the generic wire model.
Wool: Structure, Properties, and Processing
Authors: Rippon John A. , Christoe John R. , Denning Ronald J. , Evans David J. , Huson Mickey G. , Lamb Peter R. , Millington Keith R. , Pierlot Anthony P.
Published: May 2016

Wool, the fibrous coating from sheep, is the most important animal fiber used by the textile industry. It has been used continuously for several thousand years, the earliest type of fabric made from wool probably being a felt. Although the relative importance of wool as a textile fiber has declined with the increasing use of synthetic fibers, it remains important in some sectors of the market. This article discusses raw wool specification, fiber growth, its complex morphological and chemical structure, and the physical properties that make wool unique among textile fibers. Also discussed are the processing steps used to transform raw wool into consumer products, namely, scouring, carbonizing, carding, spinning, setting, dyeing, bleaching, printing, and treatments to reduce felting shrinkage, insect damage, and flammability. A novel textile fiber made from wool (OptimTM, CSIRO) is also described.
Metallocenes
Authors: Kuhlman Roger L.
Published: May 2016

Once narrowly defined as metal complexes of precise chemical formula (η5‐C5H5)2M, the word “metallocene” has evolved to represent a versatile class of polymerization technology that is slowly but significantly reshaping the polyolefin industry. Metallocene catalysts enable production of polyethylenes with narrow molecular weight and composition distributions, efficient incorporation of standard and nonstandard comonomers, an excellent spectrum of tacticity control in poly‐α‐olefins, and remarkable adaptability enabled by accumulated scientific endeavors relating ligand designs to polymer microstructures. Olefin polymerization is reviewed in some detail with emphasis on commercially relevant technologies, and a brief commercial overview is included. Nonpolymerization catalysis and (co)polymerization of functional monomers are also briefly summarized.
Natural Polymers for Dye‐Sensitized Solar Cells: Electrolytes and Electrodes
Authors: Bella Federico , Gerbaldi Claudio
Published: May 2016

It has been argued that the application of biosourced materials holds a promise for improved environmental performance. This promise has also been argued to apply to photovoltaic and solar cells. Frontrunners in this respect are the dye‐sensitized solar cells (DSSCs), also known as Grätzel cells. DSSCs are the most investigated third‐generation photovoltaic devices, due to a number of attractive features, including quasi‐flexibility and quasi‐transparency, which offer a variety of uses not applicable to glass‐based systems, such as low‐cost and ease of manufacturing via conventional roll‐printing techniques. However, important drawbacks of DSSCs are represented by the poor long‐term stability due to the volatility of the electrolyte contained organic solvent and the use of toxic and expensive components. DSSCs exploiting biosourced polymer electrolytes and electrode materials are presently under intense investigation as a next‐generation sustainable solar energy converter because of their simple structure, low manufacturing cost, and green aspect. This article details the preparation and characteristics of some recently developed electrolytes and electrodes by using biosourced materials.
Lunar meteoritic gardening rate derived from in situ LADEE/LDEX measurements
Authors: Szalay Jamey R. , Horányi Mihály
Published: May 2016

The Lunar Atmosphere and Dust Environment Explorer (LADEE) orbited the Moon for approximately 6 months, taking data with the Lunar Dust Experiment (LDEX). LDEX was uniquely equipped to characterize the current rate of lunar impact gardening as it measured the very particles taking part in this process. By deriving an average lunar dust density distribution, we calculate the rate at which exospheric dust rains back down onto the lunar surface. Near the equatorial plane, we find that approximately 40 μm/Myr of lunar regolith, with a cumulative size distribution index of 2.7, is redistributed due to meteoritic bombardment, a process which occurs predominantly on the lunar apex hemisphere.
Evaluation of geostationary satellite observations and the development of a 1–2 h prediction model for future storm intensity
Authors: Mecikalski John R. , Rosenfeld Daniel , Manzato Agostino
Published: May 2016

A study was conducted to gain insights into the use of geostationary satellite‐based indicators for characterizing and identifying growing cumulus clouds that evolve into severe weather producing convective storms. Eleven convective initiation (CI), 41 cloud top temperature–effective radius (T‐re), and 9 additional fields were formed for 340 growing cumulus clouds that were manually tracked for 2 h and checked for association with severe weather to 2–3 h into the future. The geostationary satellite data were at 5 min resolution from Meteosat‐8 on six convectively active days in 2010, 2012, and 2013. The study's goals were to determine which satellite fields are useful to forecasting severe storms and to form a simple model for predicting future storm intensity. The CI fields were applied on 3 × 3 pixel regions, and the T‐re fields were analyzed on 9 × 9 and 51 × 51 pixel domains (needed when forming T‐re vertical profiles). Of the 340 growing cumulus clouds examined, 34 were later associated with severe weather (using European Severe Weather Database reports), with the remaining being nonsevere storms. Using a multivariate analysis, transforming predictors into their empirical posterior probability, and maximizing the Peirce skill score, the best predictors were T1451 (51 × 51 pixel T, where re exceeds 14 µm), TG9 (9 × 9 pixel glaciation T surrounding a growing cloud), and ReBRTG51 (51 × 51 pixel re at the breakpoint T in the T‐re profile). Rapid cloud growth prior to severe storm formation leads to delayed particle growth, colder temperatures of the first 14 µm particles, and lower TG values.
Evaluation of reanalysis, spatially interpolated and satellite remotely sensed precipitation data sets in central Asia
Authors: Hu Zengyun , Hu Qi , Zhang Chi , Chen Xi , Li Qingxiang
Published: May 2016

The accuracy of any gridded climatic data sets is as important as their availability for regional climate and ecological studies. In this study, the accuracy of estimated precipitation in central Asia from three recently developed reanalysis data sets, Modern‐Era Retrospective Analysis for Research and Applications (MERRA), ECMWF Interim Re‐Analysis (ERA‐Interim), and Climate Forecast System Reanalysis (CFSR), is evaluated through comparisons with observations from 399 stations during 1979–2010. An interpolated precipitation data set from station observations and a satellite remotely sensed data set, Tropical Rainfall Measuring Mission (TRMM) 3B42, are included in the evaluation. Major results show that MERRA data have higher accuracy than ERA‐Interim and CFSR, although they all overestimate the observed precipitation especially in late spring and early summer months, suggesting errors in their ways of representing convective precipitation in that region. In comparison, the interpolated and satellite‐sensed data, which provide no upper air information/data, have higher accuracy. While all these data sets have difficulty in describing stations' precipitation in mountainous areas, the reanalysis data sets have particularly large discrepancies. In examining the discrepancy in the reanalysis data, a Precipitation‐Topography Partial Least Squares method is proposed to incorporate certain terrain/geographic effects on precipitation in mapping the gridded data to the station locations for comparison with the observation. The outcome suggests that the estimated station precipitation by this new method is closer to the observed than the method without considering those factors. The improvement by this method and by possible other methods taking into account different details/aspects of the influences indicates that it is only meaningful to compare the accuracy or relevance of gridded data sets to station observations in a relative sense among various data sets.
Radiation Tolerance
Authors: Battista John R
Published: May 2016

Life on earth was not exposed to high‐dose ultraviolet (UV) light or ionising radiation (IR) until the last century. Despite this fact, it is possible to isolate species from within the
Bacteria
and
Archaea
that display an unusually high resistance to the lethal effects of UV light and/or IR when compared to the rest of the tree of life. Questions concerning what mechanisms mediate this radiation tolerance and why radiotolerance evolved in an environment void of sources of high‐energy radiation define the study of these species. A great deal is known concerning the specific biochemical and physiological processes that counteract the damage caused by electromagnetic radiations, but almost all species express the proteins that mediate these processes. The nature of what distinguishes a radioresistant species from a radiosensitive species remains elusive.

Key Concepts

A small subset of
Bacteria
and
Archaea
express unusually high resistance to the lethal effects of UV and ionising radiations.

Beyond experimental evaluation, there are no overt characteristics that predict radiation tolerance; species can be defined as radiation‐tolerant only empirically.

UV and ionising radiations kill by altering the DNA structure in a manner that interferes with the irradiated cell's ability to propagate.

A number of active and passive mechanisms are known to contribute to a species' radiation tolerance, but a comprehensive explanation for radioresistance in any single species has remained elusive.

Endospores tolerate UV and ionising radiations by mechanisms not available to their vegetative forms.

The flux of UV and ionising radiations on earth have never been great enough to explain why high‐level resistance to these stresses evolved; a number of hypotheses have been put forward to account for the existence of radioresistant phenotypes.
Marker‐Assisted Crop Breeding
Authors: Houston Kelly , Russell Joanne , Ramsey Luke , Bull Hazel , Thomas Bill , Waugh Robbie
Published: May 2016

Molecular genetic markers are tools that provide an opportunity to assist crop breeders in the development of new cultivars. They can be used as a proxy for costly or difficult‐to‐phenotype traits, enabling the screening of germplasm in a more efficient and robust way. The approach of using molecular markers in breeding programs is not new, and the key aim when developing such markers is to identify loci that are in linkage disequilibrium with the trait of interest. However, interesting developments in the technology underpinning contemporary crop genetics, such as next‐generation sequencing and high‐density genotyping platforms, can be translated and applied to crop breeding, potentially improving this process.

Key Concepts

Genetic loci in linkage disequilibrium with a trait of interest can be used to design molecular markers for breeding.

Large numbers of single‐nucleotide polymorphisms (SNPs) enable marker discovery when mapping the trait, with coverage of around one marker per 2 cM to map a trait for marker‐assisted selection (MAS) in crops. A much smaller number can be used for tracking preferred alleles during the breeding process. A denser set of markers than those used in MAS would be needed for genomic selection.
Gene Copy‐Number Changes in Evolution
Authors: Bergthorsson Ulfar , Katju Vaishali
Published: May 2016

High‐throughput genomics have revealed widespread copy‐number differences within and among populations of species belonging to diverse taxonomic groups. Experimental evolution in model organisms with minimal natural selection demonstrates that genome‐wide empirical estimates of the spontaneous rates of gene duplication and deletion are extremely high and contribute to the abundance of copy‐number variation (CNV). CNVs are, on average, deleterious with respect to fitness, but their high spontaneous rates of origin can also facilitate rapid adaptation to novel environmental challenges. Duplications and deletions constitute opposing forces that shape genome complexity and size. Gene duplications are the ultimate source of new genes that confer novel phenotypes, whereas deletions remove superfluous genetic material. Furthermore, CNVs can contribute to the evolution of genetic incompatibility and speciation. Future challenges for understanding the evolutionary potential of CNVs include elucidating the relative roles of genetic drift and natural selection for the maintenance of CNVs in populations.

Key Concepts

Gene duplications are naturally occurring mutations within genomes wherein genic material is duplicated, resulting in additional copies of the duplicated gene.

Gene deletions are mutations where genic material has been deleted, thereby reducing the number of copies of the deleted gene.

Gene duplications and deletions have resulted in extensive gene copy‐number variation (CNV) in populations across all domains of life.

The evolution of gene content and genome size is the net result of duplications adding new genetic material and contributing to the evolution of new genes, and deletions, which are continuously removing genetic information.

The study of copy‐number variants at single loci has a long history in population genetics, but a systematic analysis of CNVs across whole genomes became possible only after technical breakthroughs in DNA microarray technology and whole‐genome sequencing.

The rates of spontaneous gene duplication and deletion per gene are extraordinarily high and usually much higher than the nucleotide substitution rates.

Most CNVs in natural populations are deleterious.

Both duplications and deletions can contribute to adaptive genetic variation in natural and experimental populations.

The long‐term maintenance of duplicated genes, which contribute to the evolution of novel genes, can be achieved by both positive selection on gene copy‐number and subfunctionalisation resulting from the loss of partial functions of complementary gene copies.

Gene duplication and subfunctionalisation can contribute to reproductive isolation and speciation.

A comprehensive understanding of how CNVs contribute to the evolution of genomes will require a combination of high‐throughput genomics with analysis of the functional and fitness consequences of CNVs in experimental and natural populations.
Blended Wing Body Aircraft: A Historical Perspective
Authors: Torenbeek Egbert
Published: May 2016

A blended‐wing‐body aircraft, BWB in short, is an innovative radical configuration applicable to the conceptual design of future large transport aircraft. Realization of the BWB aims at a substantial step in the continuous process of improving their flight performance, reducing atmospheric emissions, and minimizing environmental noise production due to civil aviation. The BWB belongs to the category of flying wings, an airplane layout with high aerodynamic efficiency that until recently has been practiced operationally for long‐range bomber aircraft only. Applications of the BWB are foreseen primarily in high‐subsonic jetliners with a capacity between 250 and 1000 seats. The general arrangement of a BWB does neither feature a discrete fuselage body nor an empennage. The crew, passenger seats, cargo, and luggage compartments are integrated in a thick lift‐generating central wing segment with a large center body chord and approximately equal span. The narrow‐chord outboard wings of recently proposed BWBs together form a conventional moderately loaded high‐aspect ratio swept wing.

Advanced designs for a BWB intended for commercial application were developed during the last decennium of the twentieth century in the United States by teams formed by NASA, the industry, and universities. Although various proposed concepts have quite different characteristics, they consistently indicate that a BWB can have acceptable flying qualities, improve the aerodynamic efficiency by 25%, and the fuel efficiency and CO2emissions by 35% relative to the conventional TAW. Further refinements of the concept, wind‐tunnel experiments and low‐speed flights with a remotely controlled flight test vehicle after the year 2000 have confirmed the promises of the advancements obtained by the project study teams.
Fuel Burn Reduction Through Wing Morphing
Authors: Martins Joaquim R.R.A
Published: May 2016

Changing the shape of aircraft is beneficial because they operate in a wide range of flight conditions with conflicting requirements and variations in performance. This chapter focuses on morphing systems that contribute to reducing fuel burn for commercial transport aircraft. We start with a summary of how morphing can reduce fuel burn from the system‐level viewpoint, following which we analyze the three wing‐morphing modes: planform, out‐of‐plane, and airfoil. For each of these, we review morphing mechanisms that are already in place, such as high‐lift systems, and provide an outlook on how more advanced morphing technologies can further reduce fuel burn. The impact of any morphing system must be quantified by considering all the disciplines involved, and a clean‐sheet design should be done to realize the full potential. The most promising type of morphing for the near future is variable trailing edge camber, which can tailor the aerodynamic performance and more effectively alleviate maneuver loads. Research on new materials and morphing mechanisms will make morphing systems lighter, more energy efficient, and more economical. It is just a question of time before we see aircraft wings that exhibit morphing capabilities that seem impossible today.
Advances in Turbofan Engines: AUSPerspective
Authors: Van Zante Dale E.
Published: May 2016

Turbofan engines have been the mainstay of large aircraft propulsion systems since the first turbofan‐powered commercial airliner was introduced in the late 1960s, replacing the less efficient and noisier turbojets. Engine manufacturers have continually improved the overall engine efficiency by both increasing the propulsive efficiency of the fan system and increasing the thermal efficiency of the core. Combustor technologies have also advanced, resulting in significantly lower emissions even as the overall pressure ratio of the cores has increased. Low operating costs improve aircraft economic competitiveness and motivate the efforts for fuel efficiency/noise reduction, while emissions reduction tends to be regulation driven.

The historical improvements in turbofan efficiency, noise, and emissions are reviewed. Current‐generation turbofan systems can still achieve both propulsive and thermal efficiency gains. However, the engine cycle and configuration changes that benefit efficiency can potentially have negative consequences for emissions and noise. Complementary efforts in combustion technology and noise reduction are needed for a balanced approach to engine development. The current development efforts within the United States for next‐generation engines with lower fuel burn, noise, and emissions are summarized. Additionally, research efforts are discussed for generation‐after‐next systems that are typically more electric and/or hybrid.
Aircraft Noise Modeling
Authors: Zhang Xin , Gill James , Angland David
Published: May 2016

Aircraft noise exerts an adverse influence on the environment and on people's health, and is also a performance issue. The aircraft noise problem is a complex topic that covers a number of areas, including passenger cabin and cockpit noise, ramp noise, structure‐borne noise, propulsive system noise, jet noise, airframe noise, etc., each of which requires separate modeling and mitigation treatments. These noise sources can be studied by a variety of approaches, including analytical, experimental, simulation, and modeling. Nowadays, high‐fidelity simulations, high‐fidelity scale model tests, and flight tests play increasingly important roles in aircraft design and noise assessment. However, empirical, semiempirical, and physics‐based modeling methods can still play an important role in assessment and optimization processes. These methods can be accurate, efficient, and cost‐effective. Their reliability is often based on the theory of aerodynamic sound generation, scaling laws, and correlation with wind tunnel and flight tests. This chapter introduces several models that describe the noise generated by key aircraft components such as high‐lift devices, landing gears, and rotors. Methods reviewed include semiempirical methods, component‐based methods, physics‐based methods, and analytical methods.
Impact of Airframe Systems on Green Airliner Operation
Authors: Lawson Craig , Seresinhe Ravinka
Published: May 2016

This chapter studies the impact of large commercial aircraft trajectories optimized for minimum fuel burn incorporating the on‐board systems. It shows the significant change in the fuel burn due to systems operation and builds up the case as to why a detailed aircraft systems model is required within the optimization loop.

A comparison is also made between conventional power systems and more electric architectures. In the conventional architecture, the environmental control system and the ice protection system are powered by engine bleed air, while actuators and electrics are powered by engine shaft power offtakes. In the more electric architecture, bleed offtake is eliminated, and the environmental control system and ice protection system are also powered electrically through engine shaft power offtakes.
Carbon and Noise Trading in Aviation
Authors: Wadud Zia , Gühnemann Astrid
Published: May 2016

Greenhouse gas (GHG) emissions and airport noise are among the key challenges facing the air transportation industry. This chapter looks into emissions trading schemes as a policy tool to mitigate the GHG and noise impacts of aviation. It describes the principles of emissions trading, provides examples of successful trading schemes outside of aviation, lessons learnt from them, and portrays the current status of including aviation in emissions trading. The potential for applying the tradable permit approach to noise is then discussed briefly.