bluuebunny/crossref_metadata_2025 huggingface dataset:
A unified engineering model of the first stroke in downward negative lightning
Authors: Nag Amitabh , Rakov Vladimir A.
Published: February 2016

Each stroke in a negative cloud‐to‐ground lightning flash is composed of downward leader and upward return stroke processes, which are usually modeled individually. The first stroke leader is stepped and starts with preliminary breakdown (PB) which is often viewed as a separate process. We present the first unified engineering model for computing the electric field produced by a sequence of PB, stepped leader, and return stroke processes, serving to transport negative charge to ground. We assume that a negatively charged channel extends downward in a stepped fashion during both the PB and leader stages. Each step involves a current wave that propagates upward along the newly formed channel section. Once the leader attaches to ground, an upward propagating return stroke neutralizes the charge deposited along the channel. Model‐predicted electric fields are in reasonably good agreement with simultaneous measurements at both near (hundreds of meters, electrostatic field component is dominant) and far (tens of kilometers, radiation field component is dominant) distances from the lightning channel. Relations between the features of computed electric field waveforms and model input parameters are examined. It appears that peak currents associated with PB pulses are similar to return stroke peak currents, and the observed variation of electric radiation field peaks produced by leader steps at different heights above ground is influenced by the ground corona space charge.
The upward branch of the Brewer‐Dobson circulation quantified by tropical stratospheric water vapor and carbon monoxide measurements from the Aura Microwave Limb Sounder
Authors: Minschwaner K. , Su H. , Jiang J. H.
Published: February 2016

The vertical distributions of water vapor (H2O) and carbon monoxide (CO) in the tropical lower stratosphere are controlled largely by their mixing ratios near the tropopause and by ascending motions as part of the Brewer‐Dobson circulation (BDC). The upward propagation of seasonal variations imprinted on H2O and CO vertical profiles, often referred to as the tropical “tape recorder,” can be used to derive the mean vertical velocity,
, in this region of the lower stratosphere where quasi‐horizontal mixing is not strong enough to erase the seasonal tape recorder signals. We used Aura Microwave Limb Sounder observations of the tropical tape recorders from 2004 to 2014 to derive values of
at pressures between 90 and 16 hPa (about 18 to 28 km altitude). Mean vertical profiles of
are consistent with calculated velocities derived from net radiative heating rates based on observed temperature, humidity, cloud, and trace gas amounts. Temporal variations in
are dominated by a quasi‐biennial oscillation (QBO) and seasonal cycles, with maximum upwelling coinciding with easterly phases of the QBO in zonal wind shear and during the November–December period of the seasonal cycle. Both the QBO and annual modes emphasize the importance of wave phenomena in modulating the strength of tropical upwelling in the BDC. Interannual anomalies in
are correlated with variations in the El Niño–Southern Oscillation (ENSO), with enhanced stratospheric upwelling during El Niño phases and reduced upwelling during La Niña. A small decreasing linear trend (~6%/decade) in
is observed from 2005 to 2014, although confidence is low in identifying such a trend as part of a long‐term change due to the influence of ENSO over this period.
The influence of winter cloud on summer sea ice in the Arctic, 1983–2013
Authors: Letterly Aaron , Key Jeffrey , Liu Yinghui
Published: February 2016

Arctic sea ice extent has declined dramatically over the last two decades, with the fastest decrease and greatest variability in the Beaufort, Chukchi, and East Siberian Seas. Thinner ice in these areas is more susceptible to changes in cloud cover, heat and moisture advection, and surface winds. Using two climate reanalyses and satellite data, it is shown that increased wintertime surface cloud forcing contributed to the 2007 summer sea ice minimum. An analysis over the period 1983–2013 reveals that reanalysis cloud forcing anomalies in the East Siberian and Kara Seas precondition the ice pack and, as a result, explain 25% of the variance in late summer sea ice concentration. This finding was supported by Moderate Resolution Imaging Spectroradiometer cloud cover anomalies, which explain up to 45% of the variance in sea ice concentration. Results suggest that winter cloud forcing anomalies in this area have predictive capabilities for summer sea ice anomalies across much of the central and Eurasian Arctic.
Inhomogeneous radiative forcing of homogeneous greenhouse gases
Authors: Huang Yi , Tan Xiaoxiao , Xia Yan
Published: February 2016

Radiative forcing of a homogeneous greenhouse gas (HGG) can be very inhomogeneous because the forcing is dependent on other atmospheric and surface variables. In the case of doubling CO2, the monthly mean instantaneous forcing at the top of the atmosphere is found to vary geographically and temporally from positive to negative values, with the range (−2.5–5.1 W m−2) being more than 3 times the magnitude of the global mean value (2.3 W m−2). The vertical temperature change across the atmospheric column (temperature lapse rate) is found to be the best single predictor for explaining forcing variation. In addition, the masking effects of clouds and water vapor also contribute to forcing inhomogeneity. A regression model that predicts forcing from geophysical variables is constructed. This model can explain more than 90% of the variance of the forcing. Applying this model to analyzing the forcing variation in the Climate Model Intercomparison Project Phase 5 models, we find that intermodel discrepancy in CO2 forcing caused by model climatology leads to considerable discrepancy in their projected change in poleward energy transport.
Definition of a quality factor for single site location estimates
Authors: Coetzee Petrus J. , du Plessis Warren P.
Published: February 2016

A technique to estimate the performance of single site location (SSL) based on high‐frequency direction finding for reigning ionospheric propagation conditions is described. This technique is based on classic propagation information (maximum useable frequency, frequency for optimum traffic, optimum working frequency, highest possible frequency, lowest possible frequency, etc.) which can be deduced by ray tracing through an ionospheric model such as the International Reference Ionosphere. The correlation between the elevation angle measured by an interferometric direction finder and the angles corresponding to the propagation conditions is used to assign a quality factor to the calculated SSL ground range result.
Assimilative modeling of ionospheric dynamics for nowcasting of HF propagation channels in the presence of TIDs
Authors: Nickisch L. J. , Fridman Sergey , Hausman Mark , Kraut Shawn , Zunich George
Published: February 2016

The ionospheric data assimilation algorithm called GPS Ionospheric Inversion (GPSII; pronounced “gypsy”) has been extended and employed to model the dynamic ionosphere, including medium‐scale traveling ionospheric disturbances (MS‐TIDs). MS‐TIDs are characterized by periods of 10–30 min. GPSII can assimilate many forms of ionospheric‐related data, including ionogram data and GPS L1/L2 beacon data. For this present effort, GPSII was extended to assimilate propagation time delay, integrated Doppler shift, and angle‐of‐arrival (AoA) measurements of HF transmissions from known reference points (KRPs). GPSII applies a regularization technique that constrains the solver to find the smoothest 3‐D ionosphere model that still reproduces the input data to within their respective errors of measurement. A companion paper documents the development of the assimilation capability for KRPs. In this paper we show test results of the model's performance in reproducing measured AoA variations in the presence of medium‐scale traveling ionospheric disturbances (MS‐TIDs) using near vertical incidence skywave data collected at White Sands Missile Range by the Intelligence Advanced Research Projects Activity HFGeo Program Government team. We find that using three KRPs within approximately 50 km of reference/check/nonassimilated transmitters, we can reproduce the measured AoAs of the nonassimilated transmitters to within 1.9° with 90% confidence even in the presence of highly dynamic MS‐TIDs.
Interfacial Materials for Organic Solar Cells: Recent Advances and Perspectives
Authors: Yin Zhigang , Wei Jiajun , Zheng Qingdong
Published: February 2016

Organic solar cells (OSCs) have shown great promise as low‐cost photovoltaic devices for solar energy conversion over the past decade. Interfacial engineering provides a powerful strategy to enhance efficiency and stability of OSCs. With the rapid advances of interface layer materials and active layer materials, power conversion efficiencies (PCEs) of both single‐junction and tandem OSCs have exceeded a landmark value of 10%. This review summarizes the latest advances in interfacial layers for single‐junction and tandem OSCs. Electron or hole transporting materials, including metal oxides, polymers/small‐molecules, metals and metal salts/complexes, carbon‐based materials, organic‐inorganic hybrids/composites, and other emerging materials, are systemically presented as cathode and anode interface layers for high performance OSCs. Meanwhile, incorporating these electron‐transporting and hole‐transporting layer materials as building blocks, a variety of interconnecting layers for conventional or inverted tandem OSCs are comprehensively discussed, along with their functions to bridge the difference between adjacent subcells. By analyzing the structure–property relationships of various interfacial materials, the important design rules for such materials towards high efficiency and stable OSCs are highlighted. Finally, we present a brief summary as well as some perspectives to help researchers understand the current challenges and opportunities in this emerging area of research.
Calreticulin variant stratified driver mutational status and prognosis in essential thrombocythemia
Authors: Elala Yoseph C. , Lasho Terra L. , Gangat Naseema , Finke Christy , Barraco Daniela , Haider Mahnur , Abou Hussein Ahmed K. , Hanson Curtis A. , Ketterling Rhett P. , Pardanani Animesh , Tefferi Ayalew
Published: February 2016

About 85% of patients with essential thrombocythemia (ET) harbor one of three driver mutations: JAK2, calreticulin (CALR), and MPL; the remaining ( ∼15%) are wild type for all three mutations and are referred to as being “triple negative.” Furthermore, CALR mutations in ET are structurally classified as type 1/type 1‐like or type 2/type 2‐like variants. The objective of the current study was to examine the impact of CALR mutation variant stratified driver mutational status on overall (OS), myelofibrosis‐free (MFFS), thrombosis‐free, and leukemia‐free survival (LFS) in ET; 495 patients (median age 58 years; 61% females) with ET were fully annotated for the their driver mutational status: 321 (65%) harbored JAK2, 109 (22%) CALR, and 12 (2%) MPL mutations and 11% were triple‐negative. Among the 109 CALR‐mutated cases, 52% were classified as type 1/type 1‐like and 48% as type 2/type 2‐like. In univariate analysis, triple‐negative patients displayed the best and MPL mutated the worst OS (P = 0.007); however, the difference in OS was no longer apparent on multivariable analysis that included age and sex as covariates (P = 0.5). LFS was also similar among the different mutational groups (P = 0.6) whereas MFFS was significantly shorter in MPL‐mutated patients on both univariate and multivariable analyses (age‐adjusted P = 0.02; HR 7.9, 95% CI 2.0–31.5). Also in multivariable analysis that included thrombosis history, age, and cardiovascular risk factors, the presence of JAK2 or MPL mutations was independently associated with higher risk of thrombosis (P = 0.02; HR 1.9, 95% CI 1.1–3.4). In conclusion, driver mutational status in ET does not appear to influence overall or LFS, even after CALR variant stratification. However, the presence of MPL mutations might be associated with a higher risk of fibrotic transformation and the presence of JAK2/MPL mutations with higher risk of thrombosis. Am. J. Hematol. 91:503–506, 2016. © 2016 Wiley Periodicals, Inc.
Design and Synthesis of Carbon Nanotube Segments
Authors: Segawa Yasutomo , Yagi Akiko , Matsui Katsuma , Itami Kenichiro
Published: February 2016

The selective and predictable synthesis of structurally uniform carbon nanotubes (CNTs) represents a long‐standing goal in both nanocarbon science and synthetic organic chemistry. This Review focuses on synthetic studies toward the controlled synthesis of CNTs with single chirality through the organic synthesis of CNT segments and the organic template assisted growth of CNTs.
Design, synthesis, characterization and catalytic performance of a new cellulose‐based magnetic nanocomposite in the one‐pot three‐component synthesis of α‐aminonitriles
Authors: Maleki Ali , Akhlaghi Elnaz , Paydar Reza
Published: February 2016

A sulfonated magnetic cellulose‐based nanocomposite was prepared and characterized using scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, X‐ray diffraction and Fourier transform infrared spectroscopy. Then, it was used as a green nanocatalyst for the synthesis of α‐aminonitriles by a one‐pot three‐component condensation reaction of aldehydes or ketones, amines and trimethylsilylcyanide in ethanol at room temperature. The reaction procedure is simple, yields are very high, reaction time is very short and the catalyst can be easily separated from the reaction mixture and reused in subsequent reactions without significant loss of catalytic activity. Copyright © 2016 John Wiley & Sons, Ltd.
Assessing agreement with multiple raters on correlated kappa statistics
Authors: Cao Hongyuan , Sen Pranab K. , Peery Anne F. , Dellon Evan S.
Published: February 2016

In clinical studies, it is often of interest to see the diagnostic agreement among clinicians on certain symptoms. Previous work has focused on the agreement between two clinicians under two different conditions or the agreement among multiple clinicians under one condition. Few have discussed the agreement study with a design where multiple clinicians examine the same group of patients under two different conditions. In this paper, we use the intraclass kappa statistic for assessing nominal scale agreement with such a design. We derive an explicit variance formula for the difference of correlated kappa statistics and conduct hypothesis testing for the equality of kappa statistics. Simulation studies show that the method performs well with realistic sample sizes and may be superior to a method that did not take into account the measurement dependence structure. The practical utility of the method is illustrated on data from an eosinophilic esophagitis (EoE) study.
Selective Inhibition of Aggregation and Toxicity of a Tau‐Derived Peptide using Its Glycosylated Analogues
Authors: Frenkel‐Pinter Moran , Richman Michal , Belostozky Anna , Abu‐Mokh Amjaad , Gazit Ehud , Rahimipour Shai , Segal Daniel
Published: February 2016

Protein glycosylation is a ubiquitous post‐translational modification that regulates the folding and function of many proteins. Misfolding of protein monomers and their toxic aggregation are the hallmark of many prevalent diseases. Thus, understanding the role of glycans in protein aggregation is highly important and could contribute both to unraveling the pathology of protein misfolding diseases as well as providing a means for modifying their course for therapeutic purposes. Using β‐O‐linked glycosylated variants of the highly studied Tau‐derived hexapeptide motif VQIVYK, which served as a simplified amyloid model, we demonstrate that amyloid formation and toxicity can be strongly attenuated by a glycan unit, depending on the nature of the glycan itself. Importantly, we show for the first time that not only do glycans hinder self‐aggregation, but the glycosylated peptides are capable of inhibiting aggregation of the non‐modified corresponding amyloid scaffold.
Bimodal Functionality in a Porous Covalent Triazine Framework by Rational Integration of an Electron‐Rich and ‐Deficient Pore Surface
Authors: Karmakar Avishek , Kumar Amrit , Chaudhari Abhijeet K. , Samanta Partha , Desai Aamod V. , Krishna Rajamani , Ghosh Sujit K.
Published: February 2016

A porous covalent triazine framework (CTF) consisting of both an electron‐deficient central triazine core and electron‐rich aromatic building blocks is reported. Taking advantage of the dual nature of the pore surface, bimodal functionality has been achieved. The electron deficiency in the central core has been utilized to address one of the pertinent problems in chemical industries, namely separation of benzene from its cyclic saturated congener, that is, cyclohexane. Also, by virtue of the electron‐rich aromatic rings with Lewis basic sites, aqueous‐phase chemical sensing of a nitroaromatic compound of highly explosive nature (2,4,6‐trinitrophenol; TNP) has been achieved. The present compound supersedes the performance of previously reported COFs in both the aspects. Notably, this reports the first example of pore‐surface engineering leading to bimodal functionality in CTFs.
Antibacterial, Anti‐Biofouling, and Antioxidant Prospects of Metal‐Based Nanomaterials
Authors: Chatzimitakos Theodoros , Kallimanis Aristeidis , Avgeropoulos Apostolos , Stalikas Constantine D.
Published: February 2016

Three metallic nanomaterials, i.e., iron, copper, and bimetallic iron–copper were easily synthesized using a wet‐chemical method and were properly characterized. The materials were tested against two bacterial strains, Staphylococcus aureus and Escherichia coli in order to evaluate their antibacterial activity, as well as their biofilm formation inhibition properties. The total inhibition of bacterial growth, at low µg/mL concentrations, implies the satisfactory antibacterial activity of the nanomaterials against bacteria. Between the two bacterial strains used, E. coli is more susceptible to the effect of the nanomaterials than S. aureus. However, the results for the respective biofilms are significantly different since S. aureus biofilm formation is more easily inhibited. There are differences in the way of action against the two different bacteria and diverse mechanisms of action are proposed to justify them. Furthermore, positive 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical tests demonstrated that the nanomaterials are free‐radical scavengers while TBARS (thiobarbituric acid reactive substances) tests evidenced their lipid oxidation inhibition properties, although at high concentration levels. Copper nanoparticles proved to be the most effective of the three materials tested, against DPPH radicals and lipid peroxidation followed by the Fe–Cu and lastly by the Fe nanoparticles. The intrinsic magnetic properties of iron‐based materials can provide long‐term benefits for antibacterial or anti‐biofouling treatment in water purification systems as well as for antioxidant activity purposes.
Effect of particle size on the flame retardancy of poly(butylene succinate)/Mg(OH)2 composites
Authors: Chen Hao , Wen Xin , Guan Yanyan , Min Jiakang , Wen Yanliang , Yang Hongfan , Chen Xuecheng , Li Yunhui , Yang Xiuyun , Tang Tao
Published: February 2016

Poly(butylene succinate)/magnesium hydroxide (PBS/Mg(OH)2) composites were prepared by melt compounding to investigate the effect of particle size on the flame retardancy of PBS. Their flammability properties were investigated by limiting oxygen index, UL‐94, and cone calorimeter tests, which suggested that the medium‐sized Mg(OH)2‐5 µm displayed the best flame retardancy. The residual char structure were analyzed and indicated that Mg(OH)2‐5 µm could form a better protective layer than other sized particles, leading to the better flame retardancy to PBS. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
Stability of Routine Biochemical Analytes in Whole Blood and Plasma From Lithium Heparin Gel Tubes During 6‐hr Storage
Authors: Monneret Denis , Godmer Alexandre , Le Guen Ronan , Bravetti Clotilde , Emeraud Cecile , Marteau Anthony , Alkouri Rana , Mestari Fouzi , Dever Sylvie , Imbert‐Bismut Françoise , Bonnefont‐Rousselot Dominique
Published: February 2016

Background

The stability of biochemical analytes has already been investigated, but results strongly differ depending on parameters, methodologies, and sample storage times. We investigated the stability for many biochemical parameters after different storage times of both whole blood and plasma, in order to define acceptable pre‐ and postcentrifugation delays in hospital laboratories.

Methods

Twenty‐four analytes were measured (Modular® Roche analyzer) in plasma obtained from blood collected into lithium heparin gel tubes, after 2–6 hr of storage at room temperature either before (n = 28: stability in whole blood) or after (n = 21: stability in plasma) centrifugation. Variations in concentrations were expressed as mean bias from baseline, using the analytical change limit (ACL%) or the reference change value (RCV%) as acceptance limit.

Results

In tubes stored before centrifugation, mean plasma concentrations significantly decreased after 3 hr for phosphorus (–6.1% [95% CI: –7.4 to –4.7%]; ACL 4.62%) and lactate dehydrogenase (LDH; –5.7% [95% CI: –7.4 to –4.1%]; ACL 5.17%), and slightly decreased after 6 hr for potassium (–2.9% [95% CI: –5.3 to –0.5%]; ACL 4.13%). In plasma stored after centrifugation, mean concentrations decreased after 6 hr for bicarbonates (–19.7% [95% CI: –22.9 to –16.5%]; ACL 15.4%), and moderately increased after 4 hr for LDH (+6.0% [95% CI: +4.3 to +7.6%]; ACL 5.17%). Based on RCV, all the analytes can be considered stable up to 6 hr, whether before or after centrifugation.

Conclusion

This study proposes acceptable delays for most biochemical tests on lithium heparin gel tubes arriving at the laboratory or needing to be reanalyzed.
Circulating Tumor Cells and Tumor Stem Cells Detection in the Peripheral Blood Mononuclear Cells of Breast Cancer
Authors: Wang Feng , Li Yuan‐Chun , Liu Li‐Ping , Zhang Hao‐Min , Tong Song
Published: February 2016

Background

Our aim was to retrospectively analyze the relationships between circulating tumor cells (CTCs) and the development of breast cancer, for elucidating the role of CTCs in breast cancer.

Methods

A total of 107 female patients with primary breast cancer and 48 matched healthy female volunteers were recruited. After blood collection, isolation of peripheral blood mononuclear cells (PBMC) was performed followed by the detection of cytokeratin 19 positive (CK19+) and CD44+/CD24−/low cells, as well as estrogen receptor (ER), progesterone, and CerbB2. Data were analyzed with the SPSS 20.0 software.

Results

None of the 48 volunteers were detected with CK19+ cells in their PBMC, while in 77 patients, 72% of 107 female patients with primary breast cancer, the CK19+ cells were detected. CK19+ could also be detected among patients in each grouping by different clinical staging and lymph node metastasis, with statistical differences (all P < 0.05). Further, among the 83 CK19+ specimens, 32 were also detected with CD44+/CD24−/low cells. Comparisons of CK19+ and CD44+/CD24−/low cells in patients with different clinical features (ER positive vs. ER negative, C‐erbB2 positive vs. C‐erbB2 negative) and molecular subtypes (triple‐negative breast cancer, ER positive, and C‐erbB2 positive) showed no obvious difference (all P > 0.05).

Conclusions

Both CTCs and tumor stem cells (TSCs) could be detected in the PBMC of breast cancer patients; besides, positive expression rate of CTCs might be obviously associated with the clinical stage and metastasis. Positive relationship of TSCs and the clinical stage of breast cancer was also proved in this study.
Investigating the Morphological Variations Due to Processing and Thermomechanical Treatment of Poly(propylene) Using Raman Microscopy
Authors: Sanoria Abhishek , Damodaran Subin , Schuster Tobias , Brüll Robert
Published: February 2016

Differences in the Raman spectrum of the α‐ and β‐polymorph of poly(propylene) (PP) have been identified in the form of band shifts distinct for the specific polymorph. A new method has been developed, which can ascertain the presence of the α‐polymorph. These band shifts have been used to profile both the polymorphs and variations in the crystallinity across the whole spherulite have been ascertained by carrying out a spatially resolved profiling of the degree of crystallinity. The crystalline domains in PP have been qualitatively assessed using the band shifts in the Raman spectra. This approach has then been applied to study local variations in the morphology of welds between PP plates, wherein the complex interplay between the heating and cooling patterns as well as the mechanical forces due to shearing gives rise to the development of a different morphological structure in the weld. Using Raman microscopy, a reduction in the crystallinity (≈18%) in the region of the weld seams and sporadic formation of β‐spherulites in the weld core is observed. The methodology developed has been applied to investigate a weld between PP‐H and PP‐R (PP with random ethylene copolymer), to ascertain the variations occurring upon welding in such materials.

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Imidazolium‐Based Ionic Liquids as Initiators in Ring Opening Polymerization: Ionic Conduction and Dielectric Response of End‐Functional Polycaprolactones and Their Block Copolymers
Authors: Choi U Hyeok , Mittal Anuj , Price Terry L. , Colby Ralph H. , Gibson Harry W.
Published: February 2016

Imidazolium alcohols, [R‐Im‐Z‐OH]+[X]−, are investigated as initiators for ring opening poly­merization (ROP) of ε‐caprolactone (CL). Two monomeric imidazolium alcohols {I [R = HOOC(CH2)5, Z = (CH2)11, X = Br] and III [R = n‐Bu, Z = (CH2CH2O)3CH2CH2, X = bis(trifluoromethylsulfonyl)imide (TFSI)]} are successfully utilized as initiators for ROP of CL, yielding corresponding polycaprolactones (PCL) Ia‐Br and IIIa‐TFSI. The oligoester II derived from I also acts as an initiator, providing block copolymer IIa‐Br. By anion exchange Ia‐Br and IIa‐Br are converted to Ia‐TFSI and IIa‐TFSI. The TFSI polymers have lower glass transition temperatures (Tg), resulting in higher conductivity, compared to the Br polymers. The ionic conductivities of the PCL block copolymers are higher than those of the PCL homopolymers, despite the similar Tg, because of their higher ionic content. Their static dielectric constants () increase linearly with ion content and exhibit the temperature dependence expected by Onsager, in the liquid state. The semi­crystalline PCL homopolymers, upon crystallization, undergo a significant increase in , owing to a Maxwell–Wagner–Sillars interfacial polarization. The present results demonstrate that with proper design, block copolymers have the potential to provide high ionic conductivities combined with good mechanical strength, key attributes for application of these materials in mechanical actuators.

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Biometric Protection for Mobile Devices is Now More Reliable
Authors: Schnabel Bianka , Behringer Martin
Published: February 2016

Recognizing different iris patterns from one person to the next is one of the most reliable biometric identification methods. It requires a strong light source to achieve high‐contrast images of the iris. This is a major challenge on smartphones and tablets because of the limitations in terms of space, power consumption and cost. The Kaiser Friedrich Award has now been presented for the development of a highly efficient infrared LED specifically designed for iris scans in mobile devices.
Stain‐free 3D Nanoscopy of Living Cells
Authors: Pollaro Lisa , Equis Sebastien , Dalla Piazza Bastien , Cotte Yann
Published: February 2016

The cell is the basis of all life on earth. Therefore, being capable of directly observing and measuring the internal parts of a living cell would open a wealth of possibilities. However, due to the limitation of light used as a biological probe, revealing this internal structure is either strongly limited or requires strong and tedious modifications of observed cells. State‐of‐the art microscopy techniques rely on complicated procedures (risk of errors), which require difficult and time‐consuming preparations, are invasive to the cells (risk of damaging and results falsification), and still give rather limited results. This article presents a novel non‐invasive and tomographic imaging approach for quantitative analysis and differentiation of cell components. Changes in refractive index within the cell itself provide the contrast for labeling various organelles with high precision and at a high resolution. The method can be applied to the 3D examination of living cells and biological samples under various external stimuli or drugs.
In Pursuit: Mastering Leadership Through Leader Developmental Readiness
Authors: Reichard Rebecca J. , Walker Dayna O.
Published: February 2016

This chapter defines leader developmental readiness, presents a conceptual model, and discusses implications for practitioners supporting leaders before college, during college, and in early career stages.
Leadership and Leader Developmental Self‐Efficacy: Their Role in Enhancing Leader Development Efforts
Authors: Murphy Susan Elaine , Johnson Stefanie K.
Published: February 2016

This chapter describes the role of two types of self‐efficacy—leader self‐efficacy and leader developmental efficacy—for enhancing leadership development. Practical implications for designing and developing leadership programs that take into account these two types of self‐efficacy are discussed.
Context Matters: Support for Leader Developmental Readiness
Authors: Thompson Sara E. , Reichard Rebecca J.
Published: February 2016

Leader developers need to consider support for leader developmental readiness by examining organizational culture, job design and rewards, social support, and availability and structure of leader development programming.
A Note on the Dependence of Health on Age and Education
Authors: Rohwer Götz
Published: February 2016

When investigating relationships between education and health, one has to take age into account. Conditioning on age entails conditioning on surviving, which has been argued to lead to a potential selection bias. In this note, I argue that surviving should be considered as a necessary precondition for the relationships of interest and, therefore, not as a possible source of bias. I criticize models of health trajectories that do not condition on surviving.
Is the relationship between innovation performance and knowledge management contingent on environmental dynamism and learning capability? Evidence from a turbulent market
Authors: Kamasak Rifat , Yavuz Meltem , Altuntas Gultekin
Published: February 2016

This study aims to explore the separate and combined effects of knowledge management capabilities, environmental dynamism and learning capability on innovation performance. To achieve this aim, a survey was carried out on a sample of 221 firms and a couple of hypotheses were tested. The findings showed that higher levels of environmental dynamism and learning capability made the positive linkage between knowledge management capabilities and innovation performance stronger. Based on the findings, it was suggested that whilst environmental dynamism may compel firms to assimilate and use new information better, create more new product configurations and move readily to new markets through their knowledge management capabilities, learning capability improves the understanding of organizational knowledge and helps the firm embed this knowledge into organizational processes. In this sense, environmental dynamism and learning capability moderate the relationship between knowledge management capabilities and innovation performance.
Sexual risk, substance use, mental health, and trauma experiences of gang‐involved homeless youth☆
Authors: Petering Robin
Published: February 2016

This study examined the associations of sexual risk behaviors, substance use, mental health, and trauma with varying levels of gang involvement in a sample of Los Angeles‐based homeless youths. Data were collected from 505 homeless youths who self‐reported various health information and whether they have ever identified as or been closely affiliated with a gang member. Multivariable logistic regression assessed associations of lifetime gang involvement with risk taking behaviors and negative health outcomes. Results revealed seventeen percent of youths have ever identified as a gang member and 46% as gang affiliated. Both gang members and affiliates were at greater risk of many negative behaviors than non‐gang involved youths. Gang members and affiliates were more likely to report recent methamphetamine use, cocaine use, chronic marijuana use, having sex while intoxicated, and symptoms of depression, symptoms of posttraumatic stress disorder. They were also more likely to have experienced childhood sexual abuse and witnessing family violence. Gang members were more likely to ever attempt suicide, experience recent partner violence, and report physical abuse during childhood. Results suggest that lifetime gang involvement is related to a trajectory of negative outcomes and amplified risk for youths experiencing homelessness. Additionally, being closely connected to a gang member appears to have just as much as an impact on risk as personally identifying as a gang member. Given the lack of knowledge regarding the intersection between youth homelessness and gang involvement, future research is needed to inform policies and programs that can address the specific needs of this population.
Brief report: Growth in polysubstance use among youth in the child welfare system☆
Authors: Yarnell Lisa M. , Traube Dorian E. , Schrager Sheree M.
Published: February 2016

Purpose

This paper establishes foundational knowledge on development of polysubstance use among adolescents in the U.S. child welfare system (CWS).

Method

Data on U.S. CWS adolescents from the National Study of Child and Adolescent Well‐Being were examined for rates of alcohol, marijuana, and hard drug use; and change in use over time.

Results

Past 30‐day absolute use was highest for alcohol, but daily/near‐daily use highest for marijuana. Marijuana use increased at later time points. A correlated growth model suggested covariation in use of the substances. A curve‐of‐factors model suggested that higher‐order factors explain most variation in substance use, except at the last time point. Those with lower use changed the most across time.

Conclusions

Subsequent research among CWS adolescents in the U.S. should consider substances jointly. Prevention should focus on marijuana, and later periods of adolescence and CWS involvement. Youth not thought of as at great risk upon entering the CWS may be most vulnerable.
The Role of China and the BRICS Project
Authors: Héctor Arturo Oropeza García
Published: February 2016

BRICS is an exogenous invention that was institutionalized as a convenient geopolitical market strategy, which favored each of the five BRICS countries to a greater or a lesser degree. As such, it is now a political group without deep roots and its future will be conditioned by any dividends it might yield over the coming years as a result of political, economic and social correlations and divergences.
Why Has The Transition to Democracy Led the Mexican Presidential System to Political Instability? A Proposal to Enhance Institutional Arrangements
Authors: Jorge Arturo Álvarez Tovar
Published: February 2016

Over the past two decades, Mexico has gone from an authoritarian regime to an electoral democracy. Although this change is undoubtedly positive, the institutional engineering in place and the balance of power among institutions has led to increased political instability and a latent risk of political paralysis. There is substantial literature asserting that these problems may be connected to the core characteristics of presidential systems; however, I demonstrate that in the Mexican case, it is also due to the electoral rules derived from the reforms of the 1990s and the subsequent electoral results. To substantiate this claim, I present the historical conformation of the presidential, political and electoral systems, as well as the balance of power derived from later system structures and the problems that can trigger instability. Finally, in response to the vast amount of literature that asserts that presidential systems generally shift to a parliamentary or semi-presidential system to perform better, I present an original formula based on relatively simple and feasible political reforms that can enhance the Mexican presidential system and prevent political paralysis.
Retrospective and Prospective Benefit-Cost Analyses of U.S. Anti-Smoking Policies
Authors: Jin Lawrence , Kenkel Don , Liu Feng , Wang Hua
Published: February 2016

Regulatory policies designed to improve societal welfare by “nudging” consumers to make better choices are increasingly popular. The application of benefit-cost analysis (BCA) to this sort of regulation confronts difficult theoretical and applied issues. In this analysis we contribute a worked example of behavioral BCA of U.S. anti-smoking policies. Our conceptual framework extends the standard market-based approach to BCA to allow for individual failures to make lifetime-utility-maximizing choices of cigarette consumption. We discuss how our market-based approach compares to the health benefits approach and the “consumer surplus offset” controversy in recent BCAs of several health-related regulations. We use a dynamic population model to make counterfactual simulations of smoking prevalence rates and cigarette demand over time. In our retrospective BCA the simulation results imply that the overall impact of anti-smoking policies from 1964 to 2010 is to reduce the total cigarette consumption by 28%. At a discount rate of 3% the 1964–present value of the consumer benefits from anti-smoking policies through 2010 is estimated to be $573 billion ($2010). Although we are unable to develop a hard estimate of the policies’ costs, we discuss evidence that suggests the consumer benefits substantially outweigh the costs. We then turn to a prospective BCA of future anti-smoking Food and Drug Administration (FDA) regulations. At a discount rate of 3%, the 2010–present value of the consumer benefits 30 years into the future from a simulated FDA tobacco regulation is estimated to be $100 billion. However, the nature of potential FDA tobacco regulations suggests that they might impose additional costs on consumers that make it less clear that the net benefits of the regulations will be positive.
Implications of the WTP–WTA Disparity for Benefit–Cost Analysis
Authors: Hammitt James K.
Published: February 2016

Differences between estimated willingness to accept compensation (WTA) and willingness to pay (WTP) that are larger than can be explained by standard economic theory raise questions about which measures should be used for benefit–cost analysis (BCA). These differences do not create a new problem but accentuate an existing one: the fact that the Kaldor–Hicks compensation test is ambiguous when its two components conflict. This conflict is more likely when the difference between WTA and WTP measures of a change is large. In many cases, the same individuals receive benefits and incur costs from a policy change and their preferences for the policy cannot depend on whether they ask whether their WTP for the benefit exceeds the cost they will incur or their WTA to forgo the benefit exceeds the cost they will save. In cases where benefits and costs are incurred by different people, it seems more useful to evaluate the fundamental question – whether the benefits to some justify the harms to others – than to obscure this question through a technical debate about valuation measures.
Challenges in Including BCA in Planning Approval Processes: Coal Mine Projects in New South Wales, Australia
Authors: Gillespie Robert , Bennett Jeff
Published: February 2016

A requirement for project proponents to include a benefit-cost analysis (BCA) as a component of their environmental impact assessments is implied in planning approval legislation in New South Wales, Australia. Fulfilling that requirement in the context of three large-scale expansions of coal mines has led to the application of choice modeling to estimate values for the main environmental, social, and heritage impacts. A number of particular issues have emerged in those applications: the framing of choice sets so that incentive-compatible willingness-to-pay questions are asked; the inclusion of “existence values” associated with employment opportunities provided by mines; and the incorporation of environmental offsets as part of the choice task given to respondents. The benefit-cost analyses of the coal mining projects have proven controversial. While the government agency responsible for administering the project approval process has used them as an input to decision-making, in some cases its recommendations have been “over-ridden” by the imposition of subjectively determined administrative rules. In one case, an appeal through legal channels against an approval was successful in part because the judge who heard the appeal dismissed the BCA findings because it was contrary to his own viewpoint of the merits of the case. In response, the state government has introduced legislation that requires greater “weight” to be given to the development benefits of coal mining. These responses have left the role of BCA and nonmarket valuation in the decision-making process in “limbo,” with practitioners and policy makers unsure as to the future of the methods in politically charged contexts.
Benefit-Cost Analysis in the States: Status, Impact, and Challenges
Authors: White Darcy , VanLandingham Gary
Published: February 2016

Although there is growing interest in applying benefit-cost analysis (BCA) to public policy questions, limited information is available on states’ use of this methodology. The nationwide assessment presented here begins to fill that void and finds that states and the District of Columbia are increasingly conducting BCAs and using the results to inform their policy choices. The numbers of reports released by the states and statutory mandates to conduct these studies increased substantially between 2008 and 2011. An analysis of the studies released by states shows that most lack some recommended technical features of rigorous BCA, but the reports are having a reported impact on state policy and budget decisions. Like other forms of policy research, BCA faces challenges including resource and data limitations, timing problems, and gaining policymaker buy-in for the approach and findings.
The Curiously Continuing Saga of Choosing the Measure of Welfare Changes
Authors: Knetsch Jack L.
Published: February 2016

The results of the vast array of willingness to accept compensation/ willingness to pay (WTA/WTP) disparity studies provide strong evidence that people value many losses and reductions of losses, more, and often much more, than otherwise commensurate gains or foregoing of gains. These findings also make it clear that people commonly value many changes not as final states as standard theory assumes, but as positive or negative changes relative to a neutral reference state. Consequently, not only are losses to be most accurately assessed with the WTA measure, but most positive changes that reduce losses are as well. Current practice, which rarely takes such reference dependence into account, is therefore likely to substantially understate the value and importance of projects, policies, and programs that reduce losses. Failing to take the possibilities of valuation disparities into account also appears to undermine other kinds of analyses as well, including, for example, the estimation of elasticities and setting effective levels of Pigouvian taxes.
Pricing Lives for Corporate and Governmental Risk Decisions
Authors: Viscusi W. Kip
Published: February 2016

The value of a statistical life (VSL) is the most influential single parameter used in calculating the benefits of governmental regulations. While there are some interagency differences, there is a commonality in the conceptual approach, the central role of mortality risk valuation in benefit assessment, and the general range of valuations used. Corporate risk decisions are based on a less rigorous risk analysis procedure. As typified by the General Motors ignition switch recall problems and the company’s lax corporate safety culture, there is often little systematic corporate balancing of cost and risk. This suppression of safety concerns may be attributable to the adverse experiences automobile companies had after conducting risk analyses that valued fatalities based on damages awards for wrongful death, and in response juries levied blockbuster punitive damages awards. Instead, companies should adopt the VSL in its product risk decisions. Companies should also be provided with a safe harbor reference point for responsible risk decisions. Regulatory agencies should use the VSL in setting regulatory sanctions.
Willingness to Pay to Reduce White-Collar and Corporate Crime
Authors: Cohen Mark A.
Published: February 2016

Consumer protection and financial regulatory agencies such as the Federal Trade Commission (FTC), the Securities and Exchange Commission (SEC), and the Consumer Financial Protection Bureau (CFPB) regulate various types of consumer, investor and financial frauds. Whether required or not, rulemaking proceedings oftentimes include some form of benefit-cost analysis. Thus, the benefits of proposed regulations – whether fully quantified or not – are an increasingly important component of rulemaking decisions. Anecdotal evidence suggests that the impact on victims in some cases includes significant time and financial hardships and even pain, suffering, and reduced quality of life. Further, the existence of these offenses causes nonvictims to take costly precautionary behavior and might even inhibit legitimate business activities. Yet, little is known about the true costs of consumer and financial crimes other than the out-of-pocket monetary losses incurred by victims. To the extent society wishes to optimally deter such crimes, without better data on nonmonetary costs, any benefit-cost analyses of criminal justice or prevention programs designed to reduce these crimes will inevitably underestimate program benefits. This paper provides an initial framework and empirical estimates of the willingness to pay (WTP) to reduce four types of white-collar and corporate offenses – consumer fraud, financial fraud, corporate crime, and corporate financial crime. Utilizing a contingent valuation survey approach that has been used to estimate the cost of street crimes, the average WTP for a 10% reduction in each of these four offenses is estimated to range between $35 and $85 per household. In the case of consumer fraud and financial fraud, where estimates of prevalence are available, this translates into a WTP of $1200 per consumer fraud and $12,000 for financial fraud. In contrast, the out-of-pocket costs to victims of consumer fraud have been estimated to average about $100, and about $200 to $250 for various types of financial frauds. These figures also compare favorably to the WTP for a reduced household burglary of $19,000.