bluuebunny/crossref_metadata_2025 huggingface dataset:
La economía solidaria y comunitaria en Bolivia
Authors: Wanderley Fernanda
Published: August 2017

El objetivo del presente documento es analizar los avances y desafíos del proceso de cambio en Bolivia en relación al compromiso político con otro modelo económico (plural, post extractivista y post neoliberal) a través del fortalecimiento de la economía comunitaria, la economía estatal, la economía privada y la economía cooperativa. La primera parte sintetiza la trayectoria de los movimientos sociales que canalizaron la energía política para los cambios promovidos por el Movimiento al Socialismo. La segunda parte presenta los alcances de los cambios políticos, sociales y culturales desde 2006. La tercera parte analiza las políticas de promoción del nuevo modelo económico y los resultados en los últimos diez años. La cuarta parte dibuja el nuevo campo político marcado por disputas al interior de los movimientos sociales que apoyaron el proceso. El texto cierra con consideraciones finales.

Palabras clave: Economía Plural, movimientos sociales, Movimiento al Socialismo, Economía Solidaria, Economía Comunitaria

Solidarity and commnity economy in Bolivia 

The aim of this paper is to analyze the progress and challenges of the process of change in Bolivia in relation to the political commitment with another economic model (plural, post extractive and post neoliberal) through the strengthening of the communitarian economy, the State’s economy, the economy private, and cooperative economy. The first part summarizes the trajectory of social movements that channeled the energy policy changes promoted by the Movement to Socialism. The second part presents the scope of political, social and cultural changes since 2006. The third part analyzes the policies to promote the new economic model and results in the last ten years. The fourth part draws the new political field marked by disputes within the social movements that supported the process. The text closes with final considerations.

Keywords: Plural Economy, social movements, Movement toward Socialism, Solidarity Economy, Community Economy

 
Breves comentarios sobre algunas revoluciones socialistas en el año del centenario de octubre de 1917
Authors: Moulian Tomás
Published: August 2017

El artículo corresponde a una conferencia dictada con motivo de la inauguración del año académico de la Escuela de Sociología durante el mes de Abril del 2017
Reseña "El reconocimiento de la humanidad. España, Portuga y América Latina en la génesis de la modernidad.
Authors: Tsukame Alejandro
Published: August 2017

 
Esta reseña, elaborada por Alejandro Tsukame se refiere al libro "El reconocimiento de la humanidad. España, Portugal y América Latina en la génesis de la modernidad" de Fernando Álvarez-Uría
Awareness about Sexually Transmitted Infections and Human Immunodeficiency Virus Infection among Patients with Genital Symptoms
Authors: Gyawalee Madhu , Paudyal BP , Pokhrel DB
Published: August 2017

Introduction: Sexually transmitted infections (STIs) are a major cause of public health problem. In developing countries, human immunodeficiency virus (HIV) infection is spreading rapidly, with sexually transmitted infections acting as a cofactor for the spread of HIV. Yet adequate awareness regarding these infections is lacking.Objective: To explore the knowledge and awareness about STIs and HIV infection in patients visiting Dermatology and Venereology Clinic of Institute of Medicine, Tribhuvan University Teaching Hospital (TUTH) with genital symptoms.Material and Methods: A cross sectional descriptive study was carried out in the department of dermato-venereology, TUTH for a period of one year. Total of 130 consecutive cases were enrolled. After taking consent and assuring confidentiality they were interviewed regarding awareness of STIs and HIV/AIDS.Results: Out of 130 cases, 95% and 98.5% had heard of an STI and HIV/AIDS respectively. Only 43.8% could mention discharge from genitalia as a symptom of STI whereas 38.5% could mention none. Most (91.5%) knew about the sexual mode of transmission of both STIs and HIV. None could mention about mother to child transmission of an STI, whereas 15% knew that an infected mother can transmit HIV to her baby. About 58% were aware that condoms could protect them from acquiring an STI, 63% perceived this as best method of prevention from HIV. When only 26% knew that being faithful to one partner is the best mode of prevention from an STI, 45% mentioned avoiding contact with multiple partners could prevent them from HIV transmission.Conclusions: Awareness programme on STIs as a whole could improve knowledge and awareness on HIV and STIs and hence prevent both.
Efficacy of Miniature Punch Grafting Followed by Puvasol Therapy in Refractory Stable Vitiligo
Authors: Gupta Anu , Chaudhary C , Goyal V , Lal D , Gupta SK
Published: August 2017

Introduction: Vitiligo affects approximately 2% of the worldwide population regardless of race, ethnic background or gender. When the medical methods are not successful, surgical procedures may be considered with the aim of placing a new source of pigment cells to reinitiate melanogenesis within the affected areas. This study was conducted to evaluate the efficacy of combining punch grafting followed by PUVASOL therapy in vitiligo patients. After punch grafting patients are given PUVA/PUVASOL exposure.Objective: To study the efficacy of miniature punch grafting followed by PUVASOL therapy in refractory stable vitiligo.Material and Methods: The present study was conducted in the Department of Dermatology and Venereology of Dayanand Medical College & Hospital, Ludhiana from May 2005 to March 2007. Fifteen patients of chronic stable vitiligo not responding to medical treatment and attending the outpatient department of dermatology were included in study. Appropriate statistical methods were used to analyse the data.Conclusion: Patients subjected to Miniature Punch Grafting showed more than 80% acceptance in all selected age groups and among both the sex. There was an inverse relationship between number of grafts inserted and rejection rate. Most common side effect seen was cobblestoning (60%) with few patients showing graft displacement and hematoma formation too.
Lansoprazole – Induce Black Hairy Tongue- A Case Report
Authors: Aryal Eliz , Rajbhandari M , Bhattarai Sabina
Published: August 2017

Lansoprazole induced black hairy tongue has been rarely reported. The purpose of this paper is to report a case of lansoprazole induce black hairy tongue and review the literature. A 75 year man from eastern part of Kathmandu presented with black hairy fine growth from tongue along with discomfort, burning and halitosis from oral cavity after taking lansoprazole for acute peptic disease(APD) from over the counter and after discontinuation of lansoprazole, black hairy tongue was resolving. Clinically and histopathologically: lansoprazole induced black hairy tongue was confirmed. Black hairy tongue is characterized by abnormal hypertrophy and elongation of filliform papillae. Lansoprazole is a proton-pump inhibitor (PPI) with a racemic 1:1 mixture of the enantiomers dexlansoprazole which inhibits the stomach’s production of gastric acids.
In-Depth Investigation of Wrong-Way Crashes on Divided Highways in Alabama with Use of the Haddon Matrix and Field Observations
Authors: Wang Jin , Zhou Huaguo
Published: August 2017

Few studies exist on wrong-way driving (WWD) on divided highways. Earlier findings on contributing factors and countermeasures mostly have been on freeways. This study filled the gap through the conduct of an in-depth investigation of WWD crashes exclusively on divided highways in Alabama. Extensive efforts were made to analyze WWD crash data through the use of the Haddon Matrix and field observations. General issues, contributing factors, and countermeasures were identified through in-depth analyses of individual crashes and field review of crash locations and WWD entry points. On the basis of study conclusions, recommendations are made to reduce the possibility and severity of WWD on divided highways.
Safety Effect of Diverging Diamond Interchanges on Adjacent Roadway Facilities
Authors: Claros Boris , Edara Praveen , Sun Carlos
Published: August 2017

Recent evidence has shown that the diverging diamond interchange (DDI) design improves the safety of the ramp terminals and the overall safety of the interchange. What is still not known is the safety effect that a DDI has on adjacent intersections and the speed-change lanes (SCLs) at freeway entrances and exits. This study addressed this void by examining DDI installations in Missouri. The early and many DDI implementations in Missouri provided a rich data set with which to conduct this study. Twelve major signalized intersections adjacent to the DDI ramp terminals were examined. Thirty-two SCL facilities, 16 freeway entrances, and 16 exits from 11 DDI sites also were examined. A manual review was done to assign 4,073 crash reports to corresponding facilities. The empirical Bayes (EB) method was used to estimate the safety effect of the DDI on adjacent facilities. No evidence showed that the DDI design had any effect, positive or negative, on the crashes that occurred at the entrance or exit SCLs. After DDI implementation, the changes were not statistically significant for SCL crash frequency, property damage only (PDO) crashes, and total crashes. For signalized intersections next to the DDI ramp terminals, the EB analysis showed a 6.5% decrease in fatalities and injuries, which was not statistically significant. The analysis also showed a 19.5% increase in PDO and a 12% increase in total crashes, albeit statistically significant only at the 90% confidence level. In summary, no strong evidence was found that DDIs affected safety, either negatively or positively, on adjacent SCLs or intersections.
Derivation of Decision Boundaries for Left-Turn Treatments at Signalized Intersections
Authors: Raessler Andrew , Yang Jidong J.
Published: August 2017

A new methodology is proposed to establish practical guidelines for four incremental left-turn treatments: ( a) permissive single left-turn lane, ( b) protected–permissive single left-turn lane, ( c) protected dual left-turn lanes with equal lane use, and ( d) protected dual left-turn lanes with unequal lane use. Decision boundaries were derived from the equilibrium at which the delays of two incremental treatments were equal. The benefits and costs associated with different left-turn treatments—including safety impact and construction and maintenance costs—also were considered. These benefits and costs effectually shift the boundary curves for more realistic decision making.
Outcome Assessment of Peer-to-Peer Adaptive Control Adjacent to a National Park
Authors: Richardson Lucy M. , Luker Matthew D. , Day Christopher M. , Taylor Mark , Bullock Darcy M.
Published: August 2017

In the town of Moab, Utah, a combination of seasonal tourist traffic, heavy truck traffic, and high pedestrian volumes creates a unique traffic management challenge; Moab’s remote location adds additional challenges for real-time traffic monitoring and maintaining of signal timing plans. The Main Street corridor is a strong candidate for an adaptive traffic control system (ATCS). Peer-to-peer (P2P) communication and user-definable control logic were used to develop and implement a cost-effective ATCS called “P2P adaptive control” that used only the existing local controllers and detection. The adaptive control logic adjusts green time along the mainline in response to detector inputs while keeping the side streets at the minimum time needed for pedestrian service. System performance was evaluated by comparing performance measures generated from high-resolution signal controller data before and after implementation of P2P adaptive control. The P2P adaptive control increased the through bandwidth of the corridor and reduced the number of split failures (i.e., the number of phase occurrences with insufficient green). Future work will include adjusting the algorithm to improve service on side streets and expanding P2P adaptive control to additional signals expected to be constructed in the area.
Leading Pedestrian Intervals
Authors: Sharma Anuj , Smaglik Edward , Kothuri Sirisha , Smith Oliver , Koonce Peter , Huang Tingting
Published: August 2017

To improve the safety of people walking at particular signalized intersections, traffic signal engineers may implement leading pedestrian intervals (LPIs) to provide pedestrians with a walk signal for a few seconds before the parallel vehicular green indication. Previous before-and-after studies and simple economic analyses have indicated that LPIs are low-cost tools that can reduce vehicle–pedestrian conflicts and crashes at some signalized intersections. Despite this evidence, municipalities have little guidance for when to implement LPIs. A marginal benefit–cost framework is developed with quantitative metrics and extends the concept of traffic conflicts and marginal safety–delay trade-offs to analyze the appropriateness of implementing an LPI at specific signalized intersections. The method provides guidance to help quantify the probability of a conflict occurring and direction on whether to implement an LPI at a given location from macroscopic-level inputs, including number of turning movements, crash data, and geometry. A case study with sample data indicated that an LPI was cost-effective for the scenario presented.
Connections for Integral Jointless Bridges in Seismic Regions Suitable for Accelerated Bridge Construction
Authors: Yen W. Phillip , Dekelbab Waseem , Khaleghi Bijan
Published: August 2017

Prefabricated jointless bridges consisting of pretensioned girders, posttensioned spliced girders, trapezoidal open box girders, and other types of superstructure members are often used for accelerated bridge construction. Connections in precast concrete substructures are typically made at the beam–column and column–foundation interfaces to facilitate fabrication and transportation. However, for structures in seismic regions, those interfaces represent locations of high moments and shears and large inelastic cyclic strain reversals. Jointless bridge superstructures are constructed to work integrally with the abutments. Movements due to creep, shrinkage, and temperature changes are accommodated by using flexible bearings or foundation and through incorporating relief joints at the ends of the approach slabs. In addition to reduced maintenance costs, other advantages of jointless bridges include improved structural integrity, reliability and redundancy, improved long-term serviceability, improved riding surface, reduced initial cost, and improved aesthetics. In recent times, jointless bridges have been built in seismically sensitive areas. Developing connections that can accommodate inelastic cyclic deformations and are readily constructible is the primary challenge for accelerated bridge construction in seismic regions. The AASHTO load and resistance factor design specifications do not explicitly address jointless precast, pretensioned, or posttensioned elements. The seismic design and detailing, accomplished research, and construction practices of jointless bridges, and implementation of a precast concrete bridge bent system that is intended to meet all those challenges, are presented. This paper attempts to capture the state of practice of jointless continuous bridges in seismic regions.
Damage Assessment of Tunnel Lining by Mobile Laser Scanning: Pittsburgh, Pennsylvania, Implementation Phase of FHWA SHRP 2 R06G Project
Authors: Tabrizi Kaz , Celaya Manuel , Miller Bradley S. , Wittwer Andreas , Ruzzi Louis
Published: August 2017

This paper presents the results of a nondestructive (NDT) laser scanner investigation that was conducted in one night by using the SPACETEC TS3 laser scanner in one tube of each of the Liberty and Armstrong Tunnels in Pittsburgh, Pennsylvania. A portable seismic property analyzer (PSPA), a hand-held NDT ultrasonic seismic device, was used to investigate a 200-ft-long segment of the lining of the Liberty Tunnel, for which results are also presented. The investigation was complemented with a limited inspection with traditional techniques (e.g., hammer sounding, coring) to validate NDT findings. This work was funded by FHWA under the auspices of Round 4 of the Implementation Assistance Program of the SHRP 2 R06G project. Both technologies incorporated in this study were also used and reviewed in the original SHRP 2 R06G project. With the use of the SPACETEC TS3 scanner and the supporting suite of software, the study obtained high-resolution imagery, thermal imagery, and three-dimensional profiles for the full length of the tunnels. The deliverables included complete mapping and inventory of distresses and moisture intrusion behind the lining. In the Armstrong Tunnel, SPACETEC technology was successful at detecting cold anomalies (tile debonding, water intrusion, etc.). However, in the Liberty Tunnel, detection of debonding or delamination was less effective as a result of the insufficient temperature gradient at the time of scanning within this particular tunnel. The PSPA results correlated well with results obtained from traditional techniques. Areas with a lower seismic modulus correlated well with areas showing debonding or delamination. Areas of severe debonding were also clearly identified with the PSPA device.
Fixed Fire Suppression for Eisenhower and Johnson Tunnels: Improving Facilities by Leveraging Nontransportation Expertise
Authors: Harelson Stephen , Shelly Raelene , Kraft Elizabeth , Rondinelli Steve , Miller Jason
Published: August 2017

Colorado’s state highway system contains more than 20,000 lane miles, of which less than 20 lane miles are conveyed through tunnels. Therefore, critical tunnel systems such as mechanical and electrical, systems computer controls, and closed-system hydraulics are a small fraction of Colorado’s highway system. However, the use of such systems is certain to become more widespread in the future as the state works to improve the resiliency, security, and reliability of its transportation network. Colorado’s Eisenhower–Johnson Memorial Tunnel fixed fire suppression system is an example of how such improved technologies can be successfully deployed by using the design–build contracting method to bring knowledge and expertise to a state’s department of transportation.
Patterns of C-2 fracture in the elderly: comparison of etiology, treatment, and mortality among specific fracture types
Authors: Radovanovic Ingrid , Urquhart Jennifer C. , Rasoulinejad Parham , Gurr Kevin R. , Siddiqi Fawaz , Bailey Christopher S.
Published: August 2017

OBJECTIVE

Previous studies have focused on Type II odontoid fractures and have failed to report on the effect of other C-2 fracture types on treatment and outcome. The purpose of this study was to compare patient characteristics, cause of injury, predisposing factors to fracture, treatments, and mortality rates among C-2 fracture types in a cohort of elderly patients 70 years of age and older.

METHODS

A retrospective cohort study design was used. Patients who sustained a C-2 fracture between 2002 and 2011 and who were admitted to the authors’ Level 1 trauma center were identified using the Discharge Abstract Database and the International Statistical Classification of Diseases and Related Health Problems (ICD-10) code S12.1. Fractures were classified as odontoid Type I, II, or III; hangman’s; C-2 complex (hangman’s appearance on sagittal images, Type III odontoid on coronal cuts); and other (miscellaneous). Age, sex, predisposing factors to falls, cause of injury, treatment, presence of autofusion in the subaxial cervical spine, and mortality rates were compared between fracture patterns.

RESULTS

One hundred forty-one patients were included; their mean age was 82 years. Fractures included Type II odontoid (57%), complex (19%), Type III odontoid (11%), hangman’s (8%), and other (5%). Falls from a standing height accounted for 47% of injuries, and 65% of patients had ≥ 3 risk factors for falls. Subaxial autofusion was more common in odontoid fractures (p = 0.002). Treatment was mainly nonoperative (p < 0.0001). The 1-year mortality rate was 27%. Four patients died of spinal cord injury.

CONCLUSIONS

Although not as common as Type II odontoid fractures, other C-2 fractures including hangman’s, complex, and Type III odontoid fractures accounted for close to half of the injuries in the study cohort. There were few differences between the fracture types with respect to cause of injury, predisposing factors, or mortality rate. However, surgical treatment was more common for Type II odontoid fractures.
Attention-Deficit/Hyperactivity Disorder and Fatal Accidents in Aviation Medicine
Authors: Laukkala Tanja , Bor Robert , Budowle Bruce , Sajantila Antti , Navathe Pooshan , Sainio Markku , Vuorio Alpo
Published: August 2017

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder with symptoms of inattention and/or hyperactivity-impulsivity that interfere with functioning and/or development. ADHD occurs in about 2.5% of adults. ADHD can be an excluding medical
condition among pilots due to the risk of attentional degradation and therefore impact on flight safety. Diagnosis of ADHD is complex, which complicates aeromedical assessment. This study highlights fatal accident cases among pilots with ADHD and discusses protocols to detect its presence
to help to assess its importance to flight safety.METHODS: To identify fatal accidents in aviation (including airplanes, helicopters, balloons, and gliders) in the United States between the years 2000 to 2015, the National Transportation Safety Board (NTSB) database was searched
with the terms ADHD, attention deficit hyperactivity disorder, and attention deficit disorder (ADD).RESULTS: The NTSB database search for fatal aviation accidents possibly associated with ADHD yielded four accident cases of interest in the United States [4/4894 (0.08%)]. Two of
the pilots had ADHD diagnosed by a doctor, one was reported by a family member, and one by a flight instructor. An additional five cases were identified searching for ADD [5/4894 (0.1%)]. Altogether, combined ADHD and ADD cases yielded nine accident cases of interest (0.18%).DISCUSSION:
It is generally accepted by aviation regulatory authorities that ADHD is a disqualifying neurological condition. Yet FAA and CASA provide specific protocols for tailor-made pilot assessment. Accurate evaluation of ADHD is essential because of its potential negative impact on aviation safety.Laukkala
T, Bor R, Budowle B, Sajantila A, Navathe P, Sainio M, Vuorio A. Attention-deficit/hyperactivity disorder and fatal accidents in aviation medicine. Aerosp Med Hum Perform. 2017; 88(9):871–875.
The Classification of Urban Uses
Authors: Pissourios Ioannis , Lagopoulos Alexandros
Published: August 2017

The classification of uses is one of the central issues of urban planning, since it is only by referring to groups of uses that we can achieve the simplification and, ultimately, the understanding of urban space. However, contemporary planning theory has shown very little interest in a theoretical approach to this issue. The present paper addresses the issue by integrating it into the development of an analytical theory of urban uses which it calls urbanology. Specifically, the paper starts with the description of the basic concepts and processes of classification, which are then employed to produce a general theoretical classification of urban uses. Since the classification of uses is not only a question of theoretical importance, but directly related to applied planning, the paper concludes with the elaboration of a second, alternative classification which satisfies the needs of contemporary planning practice.
Collembola cuticles and the three-phase line tension
Authors: Gundersen Håkon , Leinaas Hans Petter , Thaulow Christian
Published: August 2017

The cuticles of most springtails (Collembola) are superhydrophobic, but the mechanism has not been described in detail. Previous studies have suggested that overhanging surface structures play an important role, but such structures are not a universal trait among springtails with superhydrophobic cuticles. A novel wetting experiment with a fluorescent dye revealed the extent of wetting on exposed surface structures. Using simple wetting models to describe the composite wetting of the cuticular surface structures results in underestimating the contact angles of water. Including the three-phase line tension allows for a prediction of contact angles in the observed range. The discrepancy between the contact angle predicted by simple models and those observed is especially large in the springtail Cryptopygus clavatus which changes, seasonally, from superhydrophobic to wetting without a large change in surface structure; C. clavatus does not have overhanging surface structures. This large change in observed contact angles can be explained with a modest change of the three-phase line tension.
LMC Blue Supergiant Stars and the Calibration of the Flux-weighted Gravity–Luminosity Relationship
Authors: Urbaneja M. A. , Kudritzki R.-P. , Gieren W. , Pietrzyński G. , Bresolin F. , Przybilla N.
Published: August 2017

High-quality spectra of 90 blue supergiant stars in the Large Magellanic Cloud are analyzed with respect to effective temperature, gravity, metallicity, reddening, extinction, and extinction law. An average metallicity, based on Fe and Mg abundances, relative to the Sun of [Z] = −0.35 ± 0.09 dex is obtained. The reddening distribution peaks at

= 0.08 mag, but significantly larger values are also encountered. A wide distribution of the ratio of extinction to reddening is found ranging from

= 2 to 6. The results are used to investigate the blue supergiant relationship between flux-weighted gravity, g

f
≡ g/

, and absolute bolometric magnitude M
bol. The existence of a tight relationship, the Flux-weighted Gravity–Luminosity Relationship (FGLR), is confirmed. However, in contrast to previous work, the observations reveal that the FGLR is divided into two parts with a different slope. For flux-weighted gravities larger than 1.30 dex, the slope is similar to that found in previous work, but the relationship becomes significantly steeper for smaller values of the flux-weighted gravity. A new calibration of the FGLR for extragalactic distance determinations is provided.
Col-OSSOS: z-Band Photometry Reveals Three Distinct TNO Surface Types
Authors: Pike Rosemary E. , Fraser Wesley C. , Schwamb Megan E. , Kavelaars J. J. , Marsset Michael , Bannister Michele T. , Lehner Matthew J. , Wang Shiang-Yu , Alexandersen Mike , Chen Ying-Tung , Gladman Brett J. , Gwyn Stephen , Petit Jean-Marc , Volk Kathryn
Published: August 2017

Several different classes of trans-Neptunian objects (TNOs) have been identified based on their optical and near-infrared colors. As part of the Colours of the Outer Solar System Origins Survey (Col-OSSOS), we have obtained g-, r-, and z-band photometry of 26 TNOs using Subaru and Gemini Observatories. Previous color surveys have not utilized z-band reflectance, and the inclusion of this band reveals significant surface reflectance variations between sub-populations. The colors of TNOs in g − r and r − z show obvious structure, and appear consistent with the previously measured bi-modality in g − r. The distribution of colors of the two dynamically excited surface types can be modeled using the two-component mixing models from Fraser & Brown. With the combination of g − r and r − z, the dynamically excited classes can be separated cleanly into red and neutral surface classes. In g − r and r − z, the two dynamically excited surface groups are also clearly distinct from the cold classical TNO surfaces, which are red, with

and r − z ≲ 0.6, while all dynamically excited objects with similar g − r colors exhibit redder r − z colors. The z-band photometry makes it possible for the first time to differentiate the red excited TNO surfaces from the red cold classical TNO surfaces. The discovery of different r − z colors for these cold classical TNOs makes it possible to search for cold classical surfaces in other regions of the Kuiper Belt and to completely separate cold classical TNOs from the dynamically excited population, which overlaps in orbital parameter space.
Implications of Galaxy Buildup for Putative IMF Variations in Massive Galaxies
Authors: Blancato Kirsten , Genel Shy , Bryan Greg
Published: August 2017

Recent observational evidence for initial mass function (IMF) variations in massive quiescent galaxies at z = 0 challenges the long-established paradigm of a universal IMF. While a few theoretical models relate the IMF to birth cloud conditions, the physical driver underlying these putative IMF variations is still largely unclear. Here we use post-processing analysis of the Illustris cosmological hydrodynamical simulation to investigate possible physical origins of IMF variability with galactic properties. We do so by tagging stellar particles in the simulation (each representing a stellar population of

) with individual IMFs that depend on various physical conditions, such as velocity dispersion, metallicity, or star formation rate, at the time and place in which the stars are formed. We then follow the assembly of these populations throughout cosmic time and reconstruct the overall IMF of each z = 0 galaxy from the many distinct IMFs it is composed of. Our main result is that applying the observed relations between IMF and galactic properties to the conditions at the star formation sites does not result in strong enough IMF variations between z = 0 galaxies. Steeper physical IMF relations are required for reproducing the observed IMF trends, and some stellar populations must form with more extreme IMFs than those observed. The origin of this result is the hierarchical nature of massive galaxy assembly, and it has implications for the reliability of the strong observed trends, for the ability of cosmological simulations to capture certain physical conditions in galaxies, and for theories of star formation aiming to explain the physical origin of a variable IMF.
Phase Evolution of the Crab Pulsar between Radio and X-Ray
Authors: Yan L. L. , Ge M. Y. , Yuan J. P. , Zheng S. J. , Lu F. J. , Tuo Y. L. , Tong H. , Zhang S. N. , Lu Y. , Han J. L. , Du Y. J.
Published: August 2017

We study the X-ray phases of the Crab pulsar utilizing the 11-year observations from the Rossi X-ray Timing Explorer, 6-year radio observations from Nanshan Telescope, and the ephemeris from Jodrell Bank Observatory. It is found that the X-ray phases in different energy bands and the radio phases from the Nanshan Telescope show similar behaviors, including long-time evolution and short-time variations. Such strong correlations between the X-ray and radio phases imply that the radio and X-ray timing noises are both generated from the pulsar spin that cannot be well described by the the monthly ephemeris from the Jodrell Bank observatory. When using the Nanshan phases as references to study the X-ray timing noise, it has a significantly smaller variation amplitude and shows no long-time evolution, with a change rate of (−1.1 ± 1.1) × 10−7 periods per day. These results show that the distance of the X-ray and radio emission regions on the Crab pulsar has no detectable secular change, and it is unlikely that the timing noises resulted from any unique physical processes in the radio or X-ray emitting regions. The similar behaviors of the X-ray and radio timing noises also imply that the variation of the interstellar medium is not the origin of the Crab pulsar’s timing noises, which is consistent with the results obtained from the multi-frequency radio observations of PSR B1540−06.
Rocky Worlds Limited to ∼1.8 Earth Radii by Atmospheric Escape during a Star’s Extreme UV Saturation
Authors: Lehmer Owen R. , Catling David C.
Published: August 2017

Recent observations and analysis of low-mass (<10 M
⊕) exoplanets have found that rocky planets only have radii up to 1.5–2 R
⊕. Two general hypotheses exist for the cause of the dichotomy between rocky and gas-enveloped planets (or possible water worlds): either low-mass planets do not necessarily form thick atmospheres of a few wt.%, or the thick atmospheres on these planets easily escape, driven by X-ray and extreme ultraviolet (XUV) emissions from young parent stars. Here, we show that a cutoff between rocky and gas-enveloped planets due to hydrodynamic escape is most likely to occur at a mean radius of 1.76 ± 0.38 (2σ) R
⊕ around Sun-like stars. We examine the limit in rocky planet radii predicted by hydrodynamic escape across a wide range of possible model inputs, using 10,000 parameter combinations drawn randomly from plausible parameter ranges. We find a cutoff between rocky and gas-enveloped planets that agrees with the observed cutoff. The large cross-section available for XUV absorption in the extremely distended primitive atmospheres of low-mass planets results in complete loss of atmospheres during the ∼100 Myr phase of stellar XUV saturation. In contrast, more-massive planets have less-distended atmospheres and less escape, and so retain thick atmospheres through XUV saturation—and then indefinitely as the XUV and escape fluxes drop over time. The agreement between our model and exoplanet data leads us to conclude that hydrodynamic escape plausibly explains the observed upper limit on rocky planet size and few planets (a “valley”, or “radius gap”) in the 1.5–2 R
⊕ range.
Ground-based Parallax Confirmed by Spitzer: Binary Microlensing Event MOA-2015-BLG-020
Authors: Wang Tianshu , Zhu Wei , Mao Shude , Bond I. A. , Gould A. , Udalski A. , Sumi T. , Bozza V. , Ranc C. , Cassan A. , Yee J. C. , Han C. , Abe F. , Asakura Y. , Barry R. , Bennett D. P. , Bhattacharya A. , Donachie M. , Evans P. , Fukui A. , Hirao Y. , Itow Y. , Kawasaki K. , Koshimoto N. , Li M. C. A. , Ling C. H. , Masuda K. , Matsubara Y. , Miyazaki S. , Muraki Y. , Nagakane M. , Ohnishi K. , Rattenbury N. , Saito To. , Sharan A. , Shibai H. , Sullivan D. J. , Suzuki D. , Tristram P. J. , Yamada T. , Yonehara A. ,   (MOA Collaboration), KozŁowski S. , Mróz P. , Pawlak M. , Pietrukowicz P. , Poleski R. , Skowron J. , Soszyński I. , Szymański M. K. , Ulaczyk K. ,   (OGLE Collaboration), Beichman C. , Bryden G. , Calchi Novati S. , Carey S. , Fausnaugh M. , Gaudi B. S. , Henderson C. B. , Shvartzvald Y. , Wibking B. ,   (Spitzer Team), Albrow M. D. , Chung S.-J. , Hwang K.-H. , Jung Y. K. , Ryu Y.-H. , Shin I.-G. , Cha S.-M. , Kim D.-J. , Kim H.-W. , Kim S.-L. , Lee C.-U. , Lee Y. , Park B.-G. , Pogge R. W. ,   (KMTNet Collaboration), Street R. A. , Tsapras Y. , Hundertmark M. , Bachelet E. , Dominik M. , Horne K. , Jaimes R. Figuera , Wambsganss J. , Bramich D. M. , Schmidt R. , Snodgrass C. , Steele I. A. , Menzies J. ,   (RoboNet Collaboration)
Published: August 2017

We present the analysis of the binary gravitational microlensing event MOA-2015-BLG-020. The event has a fairly long timescale (∼63 days) and thus the light curve deviates significantly from the lensing model that is based on the rectilinear lens-source relative motion. This enables us to measure the microlensing parallax through the annual parallax effect. The microlensing parallax parameters constrained by the ground-based data are confirmed by the Spitzer observations through the satellite parallax method. By additionally measuring the angular Einstein radius from the analysis of the resolved caustic crossing, the physical parameters of the lens are determined. It is found that the binary lens is composed of two dwarf stars with masses

and

in the Galactic disk. Assuming that the source star is at the same distance as the bulge red clump stars, we find the lens is at a distance

. We also provide a summary and short discussion of all of the published microlensing events in which the annual parallax effect is confirmed by other independent observations.
Quasi-periodic Pulse Amplitude Modulation in the Accreting Millisecond Pulsar IGR J00291+5934
Authors: Bult Peter , Doesburgh Marieke van , Klis Michiel van der
Published: August 2017

We introduce a new method for analyzing the aperiodic variability of coherent pulsations in accreting millisecond X-ray pulsars (AMXPs). Our method involves applying a complex frequency correction to the time-domain light curve, allowing for the aperiodic modulation of the pulse amplitude to be robustly extracted in the frequency domain. We discuss the statistical properties of the resulting modulation spectrum and show how it can be correlated with the non-pulsed emission to determine if the periodic and aperiodic variability are coupled processes. Using this method, we study the 598.88 Hz coherent pulsations of the AMXP IGR J00291+5934 as observed with the Rossi X-ray Timing Explorer and XMM-Newton. We demonstrate that our method easily confirms the known coupling between the pulsations and a strong 8 mHz quasi-periodic oscillation (QPO) in XMM-Newton observations. Applying our method to the RXTE observations, we further show, for the first time, that the much weaker 20 mHz QPO and its harmonic are also coupled with the pulsations. We discuss the implications of this coupling and indicate how it may be used to extract new information on the underlying accretion process.
On the Impact Origin of Phobos and Deimos. I. Thermodynamic and Physical Aspects
Authors: Hyodo Ryuki , Genda Hidenori , Charnoz Sébastien , Rosenblatt Pascal
Published: August 2017

Phobos and Deimos are the two small moons of Mars. Recent works have shown that they can accrete within an impact-generated disk. However, the detailed structure and initial thermodynamic properties of the disk are poorly understood. In this paper, we perform high-resolution SPH simulations of the Martian moon-forming giant impact that can also form the Borealis basin. This giant impact heats up the disk material (around ∼2000 K in temperature) with an entropy increase of ∼1500 J K−1 kg−1. Thus, the disk material should be mostly molten, though a tiny fraction of disk material (

) would even experience vaporization. Typically, a piece of molten disk material is estimated to be meter sized owing to the fragmentation regulated by their shear velocity and surface tension during the impact process. The disk materials initially have highly eccentric orbits (e ∼ 0.6–0.9), and successive collisions between meter-sized fragments at high impact velocity (∼1–5 km s−1) can grind them down to ∼100 μm sized particles. On the other hand, a tiny amount of vaporized disk material condenses into ∼0.1 μm sized grains. Thus, the building blocks of the Martian moons are expected to be a mixture of these different sized particles from meter-sized down to ∼100 μm sized particles and ∼0.1 μm sized grains. Our simulations also suggest that the building blocks of Phobos and Deimos contain both impactor and Martian materials (at least 35%), most of which come from the Martian mantle (50–150 km in depth; at least 50%). Our results will give useful information for planning a future sample return mission to Martian moons, such as JAXA’s MMX (Martian Moons eXploration) mission.
Emission Lines in the Near-infrared Spectra of the Infrared Quintuplet Stars in the Galactic Center
Authors: Najarro F. , Geballe T. R. , Figer D. F. , Fuente D. de la
Published: August 2017

We report the detection of a number of emission lines in the 1.0–2.4 μm spectra of four of the five bright-infrared dust-embedded stars at the center of the Galactic center’s (GC) Quintuplet Cluster. Spectroscopy of the central stars of these objects is hampered not only by the large interstellar extinction that obscures all of the objects in the GC, but also by the large amounts of warm circumstellar dust surrounding each of the five stars. The pinwheel morphologies of the dust observed previously around two of them are indicative of Wolf–Rayet colliding wind binaries; however, infrared spectra of each of the five have until now revealed only dust continua steeply rising to long wavelengths and absorption lines and bands from interstellar gas and dust. The emission lines detected, from ionized carbon and from helium, are broad and confirm that the objects are dusty late-type carbon Wolf–Rayet stars.
Gas Dynamics of a Luminous z = 6.13 Quasar ULAS J1319+0950 Revealed by ALMA High-resolution Observations
Authors: Shao Yali , Wang Ran , Jones Gareth C. , Carilli Chris L. , Walter Fabian , Fan Xiaohui , Riechers Dominik A. , Bertoldi Frank , Wagg Jeff , Strauss Michael A. , Omont Alain , Cox Pierre , Jiang Linhua , Narayanan Desika , Menten Karl M.
Published: August 2017

We present new Atacama Large Millimeter/submillimeter Array (ALMA) observations of the dust continuum and [C ii] 158 μm fine structure line emission toward a far-infrared-luminous quasar, ULAS J131911.29+095051.4 at z = 6.13, and combine the new Cycle 1 data with ALMA Cycle 0 data. The combined data have an angular resolution of ∼0.″3, and resolve both the dust continuum and the [C ii] line emission on a few kiloparsec scales. The [C ii] line emission is more irregular than that of the dust continuum emission, which suggests different distributions between the dust and the [C ii]-emitting gas. The combined data confirm the [C ii] velocity gradient that we had previously detected in a lower-resolution ALMA image from the Cycle 0 data alone. We apply a tilted ring model to the [C ii] velocity map to obtain a rotation curve, and constrain the circular velocity to be 427 ± 55 km s−1 at a radius of 3.2 kpc with an inclination angle of 34°. We measure the dynamical mass within the 3.2 kpc region to be

. This yields a black-hole and host galaxy mass ratio of

, which is about

times higher than that of the present-day

/

ratio. This suggests that the supermassive black hole grows the bulk of its mass before the formation of most of the stellar mass in this quasar host galaxy in the early universe.
Secure Group Key Agreement Protocols
Authors: Balasubramanian Kannan , K. Mala
Published: August 2017

This chapter focusses on Secure Key Exchange protocols executed among a group of parties, called group key exchange (GKE) protocols. Authentication and Key Establishment are very important in any secure communication. Authentication is generally based on long-term keys which can be associated with identities. To associate identities with long-term keys, we can assume the existence of a public-key infrastructure (PKI) which provides parties with some mechanisms for secure key registration and secure access to long-term keys of prospective peers. In most cases, there is also a need for some temporary keys. The Group Key Exchange protocols can be classified as Centralized, Distributed or Contributory. A few toolkits such as Spread and Cliques for the implementation of Group Key Exchange Protocols are also discussed.
Efficient Implementation of Digital Signature Algorithms
Authors: Doraikannan Sumathi
Published: August 2017

Digital Signature is considered as an authentication tool of electronic records. The main benefits of the digital signature are cost, security, time stamping, non-repudiation and speed. Digital signature can be particularly useful for sales proposals, purchase orders and health services. In addition, this chapter also focuses on the real time applications of digital signature algorithm and its implementations. This chapter deals with the Digital signature algorithm, Digital Signature types and the way of working.
Secure Two Party Computation
Authors: Balasubramanian Kannan
Published: August 2017

The goal of secure two-party computation is to enable two parties to cooperatively evaluate a function that takes private data from both parties as input without exposing any of the private data. At the end of the computation, the participants learn nothing more than the output of the function. The two-party secure computation systems have three properties: (1) the application involves inputs from two independent parties; (2) each party wants to keep its own data secret; and (3) the participants agree to reveal the output of the computation. That is, the result itself does not imply too much information about either party's private input. Informally, the security requirements are that nothing is learned from the protocol other than the output (privacy), and that the output is distributed according to the prescribed functionality (correctness). The threat models in the two-party computation assume the presence of three different types of adversaries: 1) Semi honest, 2) Malicious and 3) Covert.
Secure Bootstrapping Using the Trusted Platform Module
Authors: Balasubramanian Kannan , Abbas Ahmed Mahmoud
Published: August 2017

The protection of Computer Hardware and Software using Cryptographic algorithms has assumed importance in the recent years. The Trusted Computing Group (TCG) has put forward certain conditions to be met by the computer hardware, software and firmware so that the devices may be considered trusted. The Trusted Platform Module is a hardware device that will authenticate the code modules contained in the Basic Input/Output System (BIOS) of a computer to ensure that the Computer System starts in a trustworthy state. This device can also protect against Memory Management attacks including Buffer Overflows and Memory Pointer attacks.
The Quadratic Sieve Algorithm for Integer Factoring
Authors: Balasubramanian Kannan , Rajakani M.
Published: August 2017

At the time when RSA was invented in 1977, factoring integers with as few as 80 decimal digits was intractable. The first major breakthrough was quadratic sieve, a relatively simple factoring algorithm invented by Carl Pomerance in 1981, which can factor numbers up to 100 digits and more. It's still the best-known method for numbers under 110 digits or so; for larger numbers, the general number field sieve (GNFS) is now used. However, the general number field sieve is extremely complicated, for even the most basic implementation. However, GNFS is based on the same fundamental ideas as quadratic sieve. The fundamentals of the Quadratic Sieve algorithm are discussed in this chapter.
Social Bookmarking in Digital Libraries
Authors: Kwanya Tom
Published: August 2017

This chapter elucidates the concept of social bookmarking, its benefits in digital libraries as well as the implications of its use on the intellectual property rights of the creators of the bookmarked works. The author concludes that digital libraries can use social bookmarking as a means of increasing access to and sharing of information resources; improve web searching; as well as to enhance collaboration in the creation and use of information. Since social bookmarks are, by and large, public descriptions of and pointers to the original resources, digital libraries do not infringe the intellectual property rights of their creators. Nonetheless, the libraries should watch against copying large volumes of content from the original resource as this may be construed as an intellectual competition with the bookmarked resource. Digital libraries are advised to develop and apply social bookmarking policies to streamline their use of social bookmarks.
Consumer's Participation Model in Virtual Communities
Authors: Shahrokh Zohreh Dehdashti , Behyar Pedram
Published: August 2017

Virtual communities are very impressive in the activities associated with the business using facilities provided on the Web and broad access to consumers. More access to users also helps virtual communities to be leading in attracting more users in competition with the other virtual communities. In this regard, providing the model of consumers' participation in virtual communities can be effective in the competitive environment from the cognitive aspects of consumer behavior. The aim of this study is to design consumers' participation model in virtual communities. The mixed method is selected as the research method and in the qualitative section, semi-structured interviews were conducted among the panel of experts; after analyzing the results using the content analysis, the designed model was finally tested. The results showed that in addition to personal and social factors and the services offered by the website, the other factors such as attitudes and we-intentions have also significant impact on the consumers' participation.