bluuebunny/crossref_metadata_2025 huggingface dataset:
AGN Activity in Nucleated Galaxies as Measured by Chandra
Authors: Foord Adi , Gallo Elena , Hodges-Kluck Edmund , Miller Brendan P. , Baldassare Vivienne F. , Gültekin Kayhan , Gnedin Oleg Y.
Published: May 2017

Motivated by theoretical expectations that nuclear star clusters (NSCs) in galactic centers may provide a favorable environment for supermassive black holes to form and/or efficiently grow, we set out to measure the fraction of nearby nucleated galaxies that also host an active galactic nucleus. We targeted a distance-limited sample of 98 objects with the Chandra X-ray Telescope, down to a uniform X-ray luminosity threshold of ∼1038 erg s−1. The sample is composed of 47 late-types and 51 early-types, enabling us to further investigate the active fraction as a function of galactic morphology. After correcting for contamination to the nuclear X-ray signal from bright X-ray binaries, we measure an active fraction

f
=
11.2

%

−
4.9

+
7.4

(1σ C.L.) across the whole sample, in agreement with previous estimates based on a heterogeneous combination of optical, X-ray, and radio diagnostics, by Seth et al. After accounting for the different stellar mass distributions in our samples, we find no statistically significant difference in the active fraction of early- versus late-type nucleated galaxies, with

f
=
10.6

%

−
4.9

+
11.9

and

10.8

%

−
6.3

+
11.3

, respectively. For the early-type nucleated galaxies, we are able to carry out a controlled comparison with a parent sample of non-nucleated galaxies covering the same stellar mass range, again finding  no statistically significant difference in the active fraction. Taken at face value, our findings suggest that the presence of an NSC does not facilitate or enhance accretion-powered emission from a nuclear supermassive black hole. This is true even for late-type nucleated galaxies, home to bluer NSCs and arguably larger gas reservoirs.
Transition from the Unipolar Region to the Sector Zone: Voyager 2, 2013 and 2014
Authors: Burlaga L. F. , Ness N. F. , Richardson J. D.
Published: May 2017

We discuss magnetic field and plasma observations of the heliosheath made by Voyager 2 (V2) during 2013 and 2014 near solar maximum. A transition from a unipolar region to a sector zone was observed in the azimuthal angle λ between ∼2012.45 and 2013.82. The distribution of λ was strongly singly peaked at

270
°

in the unipolar region and double peaked in the sector zone. The δ-distribution was strongly peaked in the unipolar region and very broad in the sector zone. The distribution of daily averages of the magnetic field strength B was Gaussian in the unipolar region and lognormal in the sector zone. The correlation function of B was exponential with an e-folding time of ∼5 days in both regions. The distribution of hourly increments of B was a Tsallis distribution with nonextensivity parameter q = 1.7 ± 0.04 in the unipolar region and q = 1.44 ± 0.12 in the sector zone. The CR–B relationship qualitatively describes the 2013 observations, but not the 2014 observations. A 40 km s−1 increase in the bulk speed associated with an increase in B near 2013.5 might have been produced by the merging of streams. A “D sheet” (a broad depression in B containing a current sheet moved past V2 from days 320 to 345, 2013. The R- and N-components of the plasma velocity changed across the current sheet.
Properties and Origin of Galaxy Velocity Bias in the Illustris Simulation
Authors: Ye Jia-Ni , Guo Hong , Zheng Zheng , Zehavi Idit
Published: May 2017

We use hydrodynamical galaxy formation simulations from the Illustris suite to study the origin and properties of galaxy velocity bias, i.e., the difference between the velocity distributions of galaxies and dark matter inside halos. We find that galaxy velocity bias decreases with increasing ratio of galaxy stellar mass to host halo mass. In general, central galaxies are not at rest with respect to dark matter halos or the core of halos, with a velocity dispersion above 0.04 times that of the dark matter. The central galaxy velocity bias is found to be mostly caused by close interactions between the central and satellite galaxies. For satellite galaxies, the velocity bias is related to their dynamical and tidal evolution history after being accreted onto the host halos. It depends on the time after the accretion and their distances from the halo centers, with massive satellites generally moving more slowly than the dark matter. The results are in broad agreement with those inferred from modeling small-scale redshift-space galaxy clustering data, and the study can help improve models of redshift-space galaxy clustering.
X-Ray Emission from the Nuclear Region of Arp 220
Authors: Paggi Alessandro , Fabbiano Giuseppina , Risaliti Guido , Wang Junfeng , Karovska Margarita , Elvis Martin , Maksym W. Peter , McDowell Jonathan , Gallagher Jay
Published: May 2017

We present an imaging and spectral analysis of the nuclear region of the ultraluminous infrared galaxy merger of Arp 220, using deep Chandra-ACIS observations summing up to

∼
300

ks

. Narrowband imaging with subpixel resolution of the innermost nuclear region reveals two distinct Fe–K emitting sources, coincident with the infrared and radio nuclear clusters. These sources are separated by 1′ (∼380 pc). The X-ray emission is extended and elongated in the eastern (E) nucleus, like the disk emission observed in millimeter radio images, suggesting a starburst dominance in this region. We estimate an Fe–K equivalent width of 

≳
1

keV

for both sources and observe 2–10 keV luminosities of

∼
2
×

10

40

erg

s

−
1

(western, W) and

∼
3
×

10

40

erg

s

−
1

(E). In the 6–7 keV band the emission from these regions is dominated by the 6.7 keV Fe xxv line, suggesting a contribution from collisionally ionized gas. The thermal energy content of this gas is consistent with the kinetic energy injection in the interstellar medium by SNe II. However, nuclear winds from a hidden active galactic nucleus (AGN) (

υ
∼
2000

km

s

−
1

) cannot be excluded. The

3
σ

upper limits on the neutral Fe–Kα flux of the nuclear regions correspond to the intrinsic AGN 2–10 keV luminosities of

<
1
×

10

42

erg

s

−
1

(W) and

<
0.4
×

10

42

erg

s

−
1

(E). For typical AGN spectral energy distributions the bolometric luminosities are

<
3
×

10

43

erg

s

−
1

(W) and

<
8
×

10

43

erg

s

−
1

(E), and black hole masses of

<
1
×

10

5

M

☉

(W) and

<
5
×

10

5

M

☉

(E) are evaluated for Eddington limited AGNs with a standard 10% efficiency.
ANALYSIS OF INTERVERTEBRAL ANGULATIONS AND MUSCULOSKELETAL SYMPTOMS OF THE SPINE IN THE MILITARY AIRCREWS OF TAIWAN
Authors: Chen Hsiang-Ho , Chung Cheng-Han , Lee Chi-Chen , Yang Cheng-Shu , Wen Yu-Shin , Lee Chi-Lien , Chiang Kwo-Tsao
Published: May 2017

Background: The purpose of this study is to investigate the prevalence of neck and low back discomfort and its association with intervertebral angulations of cervical and lumbar during neutral and flexion among aircrews.

Methods: There were 283 subjects participating in this survey. All participants finished one questionnaire each regarding complaints about musculoskeletal symptoms, and three sagittal plane radiographs. The measurements of intervertebral angulations were completed using the Cobb method for lumbar spine and the Harrison posterior tangent method for the cervical spine.

Results: In the questionnaire, 26.5% subjects self-reported neck discomfort and 33.2% subjects self-reported low back discomfort. Based on categorization by self-reported complaints, there was significant decrease in two intervertebral flexion angles of the Discomfort group than those of the Regular group, including C3/C4 and C2/C7. Based on categorization by radiological diagnoses, the abnormal group revealed significant decreases in the regular range of motion from neutral to flexion at C3/C4 segment. Lordotic angles between L1 and L5 were also found to be significantly different between the Discomfort group and the Regular group.

Conclusions: A high prevalence of neck and low back discomfort among the aircrews is revealed and needs more suitable intervention. A certain level of association between spinal discomfort and the intervertebral angulations of the lumbar spine and the cervical spine in aircrews was found when compared to the normal group.
PERFORMANCE COMPARISON OF THE POWELL AND PSO METHODS FOR MEDICAL IMAGE ALIGNMENT
Authors: Pan Meisen , Zhang Fen
Published: May 2017

In the course of aligning medical images, the similarity metric (also called alignment function) is regarded as the objective function, and the optimization method as the tool for exploring the optimal transformation parameters. In this paper, the medical image alignment is represented first and then the optimization methods are depicted in detail. With this description, by the use of the mutual information (MI) as the similarity metric, the Powell method and the particle swarm optimization (PSO) method are employed to seek the optimal transformation parameters respectively, and their optimization performances are estimated and compared. The experimental results show that the Powell and PSO methods can cater to both the multi-modality medical image alignments.
The Missed Chance to Cut Logistics Costs
Authors: Zetzmann Stefan , Fein Karl
Published: May 2017

The purpose of this paper is to analyse the current characteristics of the distribution logistics sector, assess the current status of logistic collaborations, as well as the readiness of the industry for horizontal shipper collaboration. Reviewed case studies prove that these collaborations can cut logistics costs. The data was collected from 158 shippers via an online survey. The research uses structural empirical methods to analyse the data. Practical case studies show the benefits of horizontal shipper collaboration. The focus of the research is to identify the current status of collaborations in distribution logistics and show with case studies that horizontal shipper collaboration is possible. Even though supply chain collaboration is widely discussed in the literature, it does not address horizontal shipper collaboration in distribution logistics adequately. The results educate managers to understand that horizontal shipper collaboration is an effective alternative to cut costs in distribution logistics.
Analyzing Pharmaceutical Reverse Logistics Barriers
Authors: Ali Chehab Mahmoud Salah Eldin
Published: May 2017

The purpose of this paper is to explore the barriers affecting the application of reverse logistics at a leading pharmaceutical manufacturer in Egypt. The methodological approach of Interpretive Structural Modeling (ISM) is applied to study the mutual influences across barriers listed by a preliminary case analysis, and to identify the “driving” barriers which may worsen other barriers, and “dependent” barriers influenced by the driving barriers. Findings: This paper reveals that as many as 17 reverse logistics barriers are affecting the case company in implementing reverse logistics and these barriers have been ranked into 10 levels using the ISM method. The analysis also showed that eight dependent barriers are influenced by nine driving barriers. A key finding of the analysis is that lack of regulation enforcement and lack of public awareness regarding the importance of reverse logistics are the most driving barriers influencing the rest of the identified barriers.
A Reversible Data Hiding Scheme for Efficient Management of Tele-Ophthalmological Data
Authors: Singh Abhilasha , Dutta Malay Kishore
Published: May 2017

Advancements in medical sciences and induction of advanced technologies have led to increased role of medical images in tele-diagnosis. This paper proposes a technique for easy, efficient and accurate management of distributed medical databases and alleviates the risk of any distortion in images during transmission. It also provides remedy of issues like tampering, accidentally or intentionally, authentication and reliability without affecting the perceptual properties of the image. The technique is blind and completely reversible. Values of PSNR and BER imply that the changes made to original images are imperceptible to the Human Visual System. Performance of the technique has been evaluated for fundus images and the results are extremely encouraging. The technique is lossless and conforms to the firm necessities of medical data management by maintaining perceptual quality and diagnostic significance of the images, therefore is very practical to be used in health care centers.
Parallel Distributed Patterns Mining Using Hadoop MapReduce Framework
Authors: Meddah Ishak H. A. , Belkadi Khaled
Published: May 2017

The treatment of large data is proving more difficult in different axes, but the arrival of the framework MapReduce is a solution of this problem. With it we can analyze and process vast amounts of data. It does this by distributing the computational work across a cluster of virtual servers running in a cloud or large set of machines while process mining provides an important bridge between data mining and business process analysis. The process mining techniques allow for extracting information from event logs. In general, there are two steps in process mining: correlation definition or discovery and process inference or composition. Firstly, the authors' work consists to mine small patterns from a log traces. Those patterns are the representation of the traces execution from a log file of a business process. In this step, they use existing techniques. The patterns are represented by finite state automaton or their regular expression. The final model is the combination of only two types of small patterns whom are represented by the regular expressions (ab)* and (ab*c)*. Secondly, the authors compute these patterns in parallel, and then combine those small patterns using the MapReduce framework. They have two parties: the first is the Map Step in which they mine patterns from execution traces; the second is the combination of these small patterns as reduce step. The authors' results are promising in that they show that their approach is scalable, general, and precise. It minimizes the execution time by the use of the MapReduce framework.
An Introduction to Project End Theory in Project Management
Authors: Altahtooh Umar A. , Emsley Margaret W.
Published: May 2017

Almost all project management software has lack of displaying the outcomes of projects as a feature. This is because there is no recognized way of calculating the actual project duration compared to the authorized project duration. Data were collected through a mixed method using a Critical Incident Technique (CIT) and a survey. The study finds that time error can occur throughout the project execution phase. Findings suggest that challenged projects could be successful or failed projects using a model of IT Project Outcomes Testing (MITPOT). Thus, this model establishes a foundation of Project End Theory (PET).
Reflections on Distributive Leadership for Work-Based Mobile Learning of Canadian Registered Nurses
Authors: Fahlman Dorothy (Willy)
Published: May 2017

The ubiquity, flexibility, and accessibility of mobile devices can transform how registered nurses in Canada learn beyond the confines of traditional education/training boundaries in their work settings. Many Canadian registered nurses have actively embraced mobile technologies for their work-based learning to meet their competency requirements for professional nursing practice. As self-directed learners, they are using these learning tools at point-of-need to access rich online healthcare resources, collaborate, and share information within their communities of practices. Yet, paradoxically, there are Canadian healthcare organizations that have not embraced work-based mobile learning and their contextual factors constrain and/or impede registered nurses' learning. Therefore, the goal of this reflective paper is to stimulate discussion on distributive leadership strategies for embedding this pedagogical mode of learning into Canadian healthcare workplaces for registered nurses' ongoing skills and continuing professional development.
An Evolutionary Mobility Aware Multi-Objective Hybrid Routing Algorithm for Heterogeneous WSNs
Authors: Kulkarni Nandkumar Prabhakar , Prasad Neeli Rashmi , Prasad Ramjee
Published: May 2017

Researchers have faced numerous challenges while designing WSNs and protocols in numerous applications. Amongst all sustaining connectivity and capitalizing on the network lifetime is a serious deliberation. To tackle these two problems, the authors have considered Mobile Wireless Sensor Networks (MWSNs). In this paper, the authors put forward an Evolutionary Mobility aware multi-objective hybrid Routing Protocol for heterogeneous wireless sensor networks (EMRP). EMRP selects the optimal path from source node to sink by means of various metrics such as Average Energy consumption, Control Overhead, Reaction Time, LQI, and HOP Count. The Performance of EMRP when equated with Simple Hybrid Routing Protocol (SHRP) and Dynamic Multi-Objective Routing Algorithm (DyMORA) using parameters such as Average Residual Energy (ARE), Delay and Normalized Routing Load. EMRP improves AES by a factor of 4.93% as related to SHRP and 5.15% as related to DyMORA. EMRP has a 6% lesser delay as compared with DyMORA.
Mortality of overwintering emerald ash borer (Coleoptera: Buprestidae) associated with an extreme cold event in New York, United States of America
Authors: Jones Michael I. , Gould Juli R. , Fierke Melissa K.
Published: May 2017

Severe mortality (93%) of overwintering larvae of emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), was recorded in March 2016 from green ash, Fraxinus pennsylvanica Marshall (Oleaceae), in Syracuse, New York, United States of America. In contrast, larvae collected from the same area in January exhibited <1% mortality. A strong cold front moved across New York from 13 to 15 February 2016 with temperatures plunging to nearly −40 °C in some areas. In many regions of New York where A. planipennis is established, temperatures dropped well below the reported supercooling point of overwintering larvae. To evaluate whether the extreme cold was linked to extensive mortality of larvae, trees were sampled from four areas that experienced a gradient of minimum temperatures on 14 February 2016. Overwintering mortality varied from ⩽5% to 93% among regions, with lowest survival in the coldest regions. When excised from their galleries, dead larvae were discoloured with brown spots or had black necrotic tissue in the spiracles or foregut. This is the first report of extensive cold-related mortality for this species in North America and highlights the stochastic nature of climatic extremes on invasive species populations.
Ball-Contact Injuries in 11 National Collegiate Athletic Association Sports: The Injury Surveillance Program, 2009–2010 Through 2014–2015
Authors: Fraser Melissa A. , Grooms Dustin R. , Guskiewicz Kevin M. , Kerr Zachary Y.
Published: May 2017

Context: 

Surveillance data regarding injuries caused by ball contact in collegiate athletes have not been well examined and are mostly limited to discussions of concussions and catastrophic injuries.

Objective: 

To describe the epidemiology of ball-contact injuries in 11 National Collegiate Athletic Association (NCAA) sports during the 2009–2010 through 2014–2015 academic years.

Design: 

Descriptive epidemiology study.

Setting: 

Convenience sample of NCAA programs in 11 sports (men's football, women's field hockey, women's volleyball, men's baseball, women's softball, men's and women's basketball, men's and women's lacrosse, and men's and women's soccer) during the 2009–2010 through 2014–2015 academic years.

Patients or Other Participants: 

Collegiate student-athletes participating in 11 sports.

Main Outcome Measure(s): 

Ball-contact–injury rates, proportions, rate ratios, and proportion ratios with 95% confidence intervals were based on data from the NCAA Injury Surveillance Program during the 2009–2010 through 2014–2015 academic years.

Results: 

During the 2009–2010 through 2014–2015 academic years, 1123 ball-contact injuries were reported, for an overall rate of 3.54/10 000 AEs. The sports with the highest rates were women's softball (8.82/10 000 AEs), women's field hockey (7.71/10 000 AEs), and men's baseball (7.20/10 000 AEs). Most ball-contact injuries were to the hand/wrist (32.7%) and head/face (27.0%) and were diagnosed as contusions (30.5%), sprains (23.1%), and concussions (16.1%). Among sex-comparable sports (ie, baseball/softball, basketball, and soccer), women had a larger proportion of ball-contact injuries diagnosed as concussions than men (injury proportion ratio = 2.33; 95% confidence interval = 1.63, 3.33). More than half (51.0%) of ball-contact injuries were non-time loss (ie, participation-restriction time <24 hours), and 6.6% were severe (ie, participation-restriction time ≥21 days). The most common severe ball-contact injuries were concussions (n = 18) and finger fractures (n = 10).

Conclusion: 

Ball-contact–injury rates were the highest in women's softball, women's field hockey, and men's baseball. Although more than half were non–time-loss injuries, severe injuries such as concussions and fractures were reported.
The role of emotional intelligence and organisational support on work stress of nurses in Ibadan, Nigeria
Authors: Lawal Abiodun M. , Idemudia Erhabor S.
Published: May 2017

Background: Universally, nurses have been reported to be a group at high risk of workplace stress. However, nurses’ responses to stressful situations at work could be the outcomes of individual differences and organisational factors.Objectives: We examined the independent and joint contributions of four dimensions of emotional intelligence and perceived organisational support in work stress of nurses in a teaching hospital in Nigeria.Methods: The study was a cross-sectional survey research design, which selected 228 (41 male and 187 female nurses) nurses through the use of convenience sampling. Questionnaires comprising demographics with work stress, organisational support and emotional intelligence scales were administered to the sampled 228 nurses in the study. Data were analysed with the use of correlational matrix and hierarchical multiple regression.Results: Self-emotion appraisal, others’ emotion appraisal, use of emotion, regulation of emotion and perceived organisational support were found to have joint contributions to explaining work stress among nurses. Others’ emotion appraisal, use of emotion and perceived organisational support were found to have independent relationships with work stress.Conclusion: Our findings stress that judgement of others’ emotions, accurate use of emotion by nurses and support from management of the hospital are most important in explaining their reactions towards work-related stress.
The distance-dependent two-point function of triangulations: a new derivation from old results
Authors: Guitter Emmanuel
Published: May 2017

We present a new derivation of the distance-dependent two-point function of random planar triangulations. As it is well-known, this function is intimately related to the generating functions of so-called slices, which are pieces of triangulation having boundaries made of shortest paths of prescribed length. We show that the slice generating functions are fully determined by a direct recursive relation on their boundary length. Remarkably, the kernel of this recursion is some quantity introduced and computed by Tutte a long time ago in the context of a global enumeration of planar triangulations. We may thus rely on these old results to solve our new recursion relation explicitly in a constructive way.
Zero width limit of the heat equation on moving thin domains
Authors: Miura Tatsu-Hiko
Published: May 2017

We study the behavior of a variational solution to the Neumann type problem of the heat equation on a moving thin domain

\Omega_{\varepsilon}(t)

that converges to an evolving surface

\Gamma (t)

as the width of

\Omega_\varepsilon(t)

goes to zero. We show that, under suitable assumptions, the average in the normal direction of

\Gamma(t)

of a variational solution to the heat equation converges weakly in a function space on

\Gamma(t)

as the width of

\Omega_\varepsilon(t)

goes to zero, and that the limit is a unique variational solution to a limit equation on

\Gamma(t)

, which is a new type of linear diffusion equation involving the mean curvature and the normal velocity of

\Gamma(t)

. We also estimate the difference between variational solutions to the heat equation on

\Omega_\varepsilon(t)

and the limit equation on

\Gamma(t)

.
A weak formulation for a rate-independent delamination evolution with inertial and viscosity effects subjected to unilateral constraint
Authors: Scala Riccardo
Published: May 2017

We consider a system of two viscoelastic bodies attached on one side by an adhesive where a delamination process occurs. We study the dynamic of the system for small strains, subjected to external forces, suitable boundary conditions, and an unilateral constraint on the jump of the displacement at the interface between the bodies. The constraint arises in a graph inclusion, while the delamination coefficient evolves in a rate-independent way. We prove the existence of a weak solution to the corresponding system of PDEs.
Minimising a relaxed Willmore functional for graphs subject to boundary conditions
Authors: Deckelnick Klaus , Grunau Hans-Christoph , Röger Matthias
Published: May 2017

For a bounded smooth domain in the plane and smooth boundary data we consider the minimisation of the Willmore functional for graphs subject to Dirichlet or Navier boundary conditions. For

H^2

-regular graphs we show that bounds for the Willmore energy imply bounds on the surface area and on the height of the graph. We then consider the

L^1

-lower semicontinuous relaxation of the Willmore functional, which is shown to be indeed its largest possible extension, and characterise properties of functions with finite relaxed energy. In particular, we deduce compactness and lower-bound estimates for energy-bounded sequences. The lower bound is given by a functional that describes the contribution by the regular part of the graph and is defined for a suitable subset of

BV(\Omega)

. We further show that finite relaxed Willmore energy implies the attainment of the Dirichlet boundary data in an appropriate sense, and obtain the existence of a minimiser in

L^\infty\cap BV

for the relaxed energy. Finally, we extend our results to Navier boundary conditions and more general curvature energies of Canham–Helfrich type.
Evaporating brine from frost flowers with electron microscopy and implications for atmospheric chemistry and sea-salt aerosol formation
Authors: Yang Xin , Neděla Vilém , Runštuk Jiří , Ondrušková Gabriela , Krausko Ján , Vetráková Ľubica , Heger Dominik
Published: May 2017

Abstract. An environmental scanning electron microscope (ESEM) was used for the first time to obtain well-resolved images, in both temporal and spatial dimensions, of lab-prepared frost flowers (FFs) under evaporation within the chamber temperature range from −5 to −18 °C and pressures above 500 Pa. Our scanning shows temperature-dependent NaCl speciation: the brine covering the ice was observed at all conditions, whereas the NaCl crystals were formed at temperatures below −10 °C as the brine oversaturation was achieved. Finger-like ice structures covered by the brine, with a diameter of several micrometres and length of tens to 100 µm, are exposed to the ambient air. The brine-covered fingers are highly flexible and cohesive. The exposure of the liquid brine on the micrometric fingers indicates a significant increase in the brine surface area compared to that of the flat ice surface at high temperatures; the NaCl crystals formed can become sites of heterogeneous reactivity at lower temperatures. There is no evidence that, without external forces, salty FFs could automatically fall apart to create a number of sub-particles at the scale of micrometres as the exposed brine fingers seem cohesive and hard to break in the middle. The fingers tend to combine together to form large spheres and then join back to the mother body, eventually forming a large chunk of salt after complete dehydration. The present microscopic observation rationalizes several previously unexplained observations, namely, that FFs are not a direct source of sea-salt aerosols and that saline ice crystals under evaporation could accelerate the heterogeneous reactions of bromine liberation.
Heterogeneous uptake of ammonia and dimethylamine into sulfuric and oxalic acid particles
Authors: Sauerwein Meike , Chan Chak Keung
Published: May 2017

Abstract. Heterogeneous uptake is one of the major mechanisms governing the amounts of short-chain alkylamines and ammonia (NH3) in atmospheric particles. Molar ratios of aminium to ammonium ions detected in ambient aerosols often exceed typical gas phase ratios. The present study investigated the simultaneous uptake of dimethylamine (DMA) and NH3 into sulfuric and oxalic acid particles at gaseous DMA ∕ NH3 molar ratios of 0.1 and 0.5 at 10, 50 and 70 % relative humidity (RH). Single-gas uptake and co-uptake were conducted under identical conditions and compared. Results show that the particulate dimethyl-aminium/ammonium molar ratios (DMAH ∕ NH4) changed substantially during the uptake process, which was severely influenced by the extent of neutralisation and the particle phase state. In general, DMA uptake and NH3 uptake into concentrated H2SO4 droplets were initially similarly efficient, yielding DMAH ∕ NH4 ratios that were similar to DMA ∕ NH3 ratios. As the co-uptake continued, the DMAH ∕ NH4 gradually dropped due to a preferential uptake of NH3 into partially neutralised acidic droplets. At 50 % RH, once the sulfate droplets were neutralised, the stronger base DMA displaced some of the ammonium absorbed earlier, leading to DMAH ∕ NH4 ratios up to four times higher than the corresponding gas phase ratios. However, at 10 % RH, crystallisation of partially neutralised sulfate particles prevented further DMA uptake, while NH3 uptake continued and displaced DMAH+, forming almost pure ammonium sulfate. Displacement of DMAH+ by NH3 has also been observed in neutralised, solid oxalate particles. The results can explain why DMAH ∕ NH4 ratios in ambient liquid aerosols can be larger than DMA ∕ NH3, despite an excess of NH3 in the gas phase. An uptake of DMA to aerosols consisting of crystalline ammonium salts, however, is unlikely, even at comparable DMA and NH3 gas phase concentrations.
Volcanic ash modeling with the NMMB-MONARCH-ASH model: quantification of off-line modeling errors
Authors: Marti Alejandro , Folch Arnau
Published: May 2017

Abstract. Volcanic ash modeling systems are used to simulate the atmospheric dispersion of volcanic ash and to generate forecasts that quantify the impacts from volcanic eruptions on infrastructures, air quality, aviation, and climate. The efficiency of response and mitigation actions is directly associated to the accuracy of the volcanic ash cloud detection and modeling systems. Operational forecasts build on off-line coupled modeling systems where meteorological variables are updated at the specified coupling intervals. Despite the concerns from other communities regarding the accuracy of this strategy, the quantification of the systematic errors and shortcomings associated to the off-line modeling systems has received no attention. This paper employs the NMMB-MONARCH-ASH model to quantify these errors by employing different quantitative and categorical evaluation scores. The skills of the off-line coupling strategy are compared against those from an on-line forecast considered to be the best estimate of the true outcome. Case studies are considered for a synthetic eruption with constant eruption source parameters and for two historical events, which suitably illustrate the severe aviation disruptive effects of European (2010 Eyjafjallajökull) and South-American (2011 Cordón Caulle) volcanic eruptions. Evaluation scores indicate that systematic errors credited to off-line modeling are of the same order of magnitude that those associated to the source term uncertainties. In particular, traditional off-line forecasts employed in operational model setups can result in significant uncertainties, failing to reproduce, in the worst cases, up to 45–70 % of the ash cloud of an on-line forecast. These inconsistencies are anticipated to be even more relevant in scenarios where the meteorological conditions change rapidly in time. The outcome of this paper encourages operational groups responsible for real‐time advisories for aviation to consider employing computationally efficient on-line dispersal models.
A biophysical approach using drought stress factor for daily estimations of
evapotranspiration and CO2 uptake in high-energy water-limited
environments
Authors: Helman David , Lensky Itamar M. , Osem Yagil , Rohatyn Shani , Rotenberg Eyal , Yakir Dan
Published: May 2017

Abstract. Estimations of ecosystem-level evapotranspiration (ET) and CO2 uptake in water-limited environments are scarce and scaling up ground-level measurements is not straightforward. A biophysical approach was previously proposed for ecosystem-level assessment relying on vegetation index and meteorological data (RS-Met) in temperate Mediterranean ecosystems. However, these RS-Met models have not been tested yet in extreme high-energy water-limited ecosystems that suffer from continuous stress conditions. Owing to the lack of ET and CO2 flux estimations in the Eastern Mediterranean, we examined the RS-Met approach using a newly developed mobile lab system and the single active Fluxnet station operating in this region, in seven forest and non-forest sites across a climatic transect in Israel (280–770 mm y−1). The RS-Met models were used with and without the addition of a seasonal drought stress factor (fDS), which was based on daily rainfall, temperature and radiation data. Results show that the RS-Met models with the inclusion of the fDS were significantly improved compared to the non-fDS models (r=0.64–0.91 compared to 0.05–0.80; P=0.06 and r=0.72–0.92 compared to r=0.56–0.90; P<0.01 for ET and GPP, respectively). These, successfully tracked observed seasonal changes in ET and GPP across sites (ETMOD=0.94×ETEC+0.28; r=0.82; MAE=0.54 mm d−1; N=243 d, and GPPMOD = 0.99×GPPEC + 0.51; r=0.86; MAE=1.03 gC m−2 d−1; N=252 d). Modeled ET and GPP also agreed well with eddy covariance estimates at the annual timescale in the Fluxnet station located in the dryland pine forest of Yatir (266±61 vs. 257±58 mm y−1 and 765±112 vs. 748±124 gC m−2 y−1 for ET and GPP, respectively). Using the RS-Met models, we were able to show the effect of afforestation on water vapor and CO2 fluxes in this region. Afforestation was responsible for a significant increase in water use efficiency (WUE) with positive effect decreasing when moving from dry to more humid environments, strengthening the importance of drylands afforestation. This simple but yet robust biophysical approach show a promise for reliable ecosystem-level estimations of ET and CO2 uptake in extreme high-energy water-limited environments when adjusting for drought stress effects.
Current challenges of implementing anthropogenic land-use and land-cover change in models contributing to climate change assessments
Authors: Prestele Reinhard , Arneth Almut , Bondeau Alberte , de Noblet-Ducoudré Nathalie , Pugh Thomas A. M. , Sitch Stephen , Stehfest Elke , Verburg Peter H.
Published: May 2017

Abstract. Land-use and land-cover change (LULCC) represents one of the key drivers of global environmental change. However, the processes and drivers of anthropogenic land-use activity are still overly simplistically implemented in terrestrial biosphere models (TBMs). The published results of these models are used in major assessments of processes and impacts of global environmental change, such as the reports of the Intergovernmental Panel on Climate Change (IPCC). Fully coupled models of climate, land use and biogeochemical cycles to explore land use–climate interactions across spatial scales are currently not available. Instead, information on land use is provided as exogenous data from the land-use change modules of integrated assessment models (IAMs) to TBMs. In this article, we discuss, based on literature review and illustrative analysis of empirical and modeled LULCC data, three major challenges of this current LULCC representation and their implications for land use–climate interaction studies: (I) provision of consistent, harmonized, land-use time series spanning from historical reconstructions to future projections while accounting for uncertainties associated with different land-use modeling approaches, (II) accounting for sub-grid processes and bidirectional changes (gross changes) across spatial scales, and (III) the allocation strategy of independent land-use data at the grid cell level in TBMs. We discuss the factors that hamper the development of improved land-use representation, which sufficiently accounts for uncertainties in the land-use modeling process. We propose that LULCC data-provider and user communities should engage in the joint development and evaluation of enhanced LULCC time series, which account for the diversity of LULCC modeling and increasingly include empirically based information about sub-grid processes and land-use transition trajectories, to improve the representation of land use in TBMs. Moreover, we suggest concentrating on the development of integrated modeling frameworks that may provide further understanding of possible land–climate–society feedbacks.
Correct boundary conditions for DNS models of
nonlinear acoustic-gravity waves forced by
atmospheric pressure variations
Authors: Kurdyaeva Yuliya , Kshevetskii Sergey , Gavrilov Nikolay , Kulichkov Sergey
Published: May 2017

Abstract. Currently, international networks exist for high-resolution microbarograph recording wave pressure variations at the surface of the Earth. This increases interest in simulating propagation of waves caused by variations of atmospheric pressure. Such mathematical problem involves a set of primitive nonlinear hydrodynamic equations with lower boundary conditions in the form of wavelike pressure variations at the Earth's surface. To analyze the correctness of the problem, the linearized equations are used near the ground for small amplitudes of surface wave excitation. The method of wave energy functional shows that in nondissipative approximation the solution of the boundary problem is uniquely determined by the variable pressure field at the Earth's surface. Respective dissipative problem has also unique solution with the appropriate choice of lower boundary conditions for temperature and velocity components. To test the numerical algorithm, analytical solutions of the linearized equations for acoustic and gravity wave modes are used. Reasonable agreements of numerical and analytical solutions are obtained. Analytical studies show possibilities of sharp changes of temperature and density near the ground. Numerical simulations confirm these analytical results. Obtained algorithms and computer codes can be used for simulations of atmospheric wave propagation from the pressure variations at the Earth's surface.
A coupled stochastic rainfall-evapotranspiration model for hydrological impact analysis
Authors: Pham Minh Tu , Vernieuwe Hilde , De Baets Bernard , Verhoest Niko E. C.
Published: May 2017

Abstract. A hydrological impact analysis concerns the study of the consequences of certain scenarios on one or more variables or fluxes in the hydrological cycle. In such exercise, discharge is often considered, as especially extreme high discharges often cause damage due to the coinciding floods. Investigating extreme discharges generally requires long time series of precipitation and evapotranspiration that are used to force a rainfall-runoff model. However, such kind of data may not be available and one should resort to stochastically-generated time series, even though the impact of using such data on the overall discharge, and especially on the extreme discharge events is not well studied. In this paper, stochastically-generated rainfall and coinciding evapotranspiration time series are used to force a simple conceptual hydrological model. The results obtained are comparable to the modelled discharge using observed forcing data. Yet, uncertainties in the modelled discharge increase with an increasing number of stochastically-generated time series used. Notwithstanding this finding, it can be concluded that using a coupled stochastic rainfall-evapotranspiration model has a large potential for hydrological impact analysis.
Family Ethics
Authors: Bøyum Steinar , Gamlund Espen
Published: May 2017

For this special issue of the Nordic Journal of Applied Ethics, we have selected four papers that address, directly or indirectly, some key issues in family ethics.
Granulomatous Inflammatory Response to a Microchip Implanted in a Dog for Eight Years
Authors: Legallet Claire , Mankin Kelley Thieman , Spaulding Kathy , Mansell Joanne
Published: May 2017

An 8 yr old neutered male springer spaniel dog was referred to Texas A&M University, College of Veterinary Medicine for a large, firm, fixed mass, located in the dorsal cervical tissue. The dog was otherwise healthy and had undergone microchip implantation approximately 8 yr prior. Radiographs, ultrasound, and microchip scanner confirmed the presence of a microchip within the mass. The microchip and associated mass were surgically excised, and histopathologic examination revealed granulomatous inflammation surrounding a cracked microchip. This case represents the first report of a granulomatous inflammatory response to a microchip 8 yr after implantation in a dog and highlights an important differential diagnosis.
Paramedian Submandibular Approach for Removal of Foreign Bodies in the Pterygoid Muscle in Two Dogs
Authors: Gettinger Elizabeth , Smeak Daniel , Marolf Angela
Published: May 2017

The purpose of this report is to document a unique location of an oropharyngeal foreign body, diagnosed via contrast computed tomography (CT), as well as a novel surgical approach to the pterygoid muscle region. Oropharyngeal foreign objects are an uncommon but potentially serious disease that can lead to chronic abscessation and pain. Two dogs were presented with chronic complaints, including pain and inability to fully open the mouth for a 1 yr and 5 mo duration, respectively. There was no history or evidence of skin sinus or submandibular/cervical swelling on physical examination of either dog. Both dogs had normal oropharyngeal anatomy with the exception of an asymmetric contrast-enhancing lesion within the pterygoid muscle on CT imaging. As there were no gross abnormalities visible during surgery, the use of contrast CT was vital in order to isolate the focus of infection. A paramedian submandibular approach was used to explore this region, and in both cases, foreign material was successfully removed with subsequent resolution of clinical signs. The dogs were immediately free of clinical signs and showed no recurrence for at least 8 and 17 mo after the exploration, respectively. A novel surgical approach is described to remove oropharyngeal foreign objects and necrotic debris within the pterygoid muscle.
Presentación No.44
Authors: Rodríguez Wendy Bellanger
Published: May 2017

La revolución digital y los cambios institucionales que se han producido en casi todos los países del mundo, han venido a poner en cuestión el modelo tradicional de universidad. Inmersa en una especie de torbellino de transformaciones, la universidad se ha visto obligada a redefinir sus funciones y, más profundamente, su propia identidad institucional, Y le ha venido haciendo como quien camina a tientas, experimentando nuevas respuestas y soluciones, a sabiendas de que éstas poseen un carácter "piloto" y que deberán ser revisadas y reformuladas constantemente, si no quiere quedarse a la zaga de un "cambio de civilización" que no tiene más de 30 años de haberse puesto en marcha, pero que se prolongará, muy probablemente, hasta bien entrado el primer siglo del próximo milenio.
Una universidad que investiga: nuestra universidad ante el reto de la novedad
Authors: Valdés SJ Eduardo
Published: May 2017

Entre las múltiples reflexiones sobre la Universidad y el papel que ésta debe jugar en la sociedad donde ofrece sus servicios, está aquella que la invita a ser presente, a recuperar su papel de articuladora de la sociedad.
La investigación en universidades pequeñas
Authors: Nelson Connie
Published: May 2017

Me siento muy complacida de estar con ustedes en este seminario internacional sobre 'La investigación en Universidades pequeñas" para debatir un asunto tan complejo, que se encuentra en el corazón de la vida Universitaria. Antes de abordar el tema que me solicitaron, quisiera compartir con ustedes un par de informaciones introductorias. La primera es una breve presentación de ml misma. La segunda, un rápido vistazo de la Universidad de Lakehead, la institución donde llevo a cabo mi trabajo.
Liberalización financiera y segmentación de mercados
Authors: Dauner Isabel
Published: May 2017

En contra de la llamada "Escuela de la Represión Financiera", este artículo muestra, a partir de la experiencia de Nicaragua, que la liberalización financiera no es una condición suficiente para el desarrollo de un sistema financiero eficiente. En el sector rural nicaragüense no existen mercados financieros capaces de jugar su rol de intermediador entre ahorrantes e inversionistas, sino segmentos de mercado aislados entre sí. En éste, como en Otros países del continente latinoamericano, encontramos la presencia de un conjunto de limitantes estructurales e institucionales, más acentuadas aún en las zonas rurales, que no son tomadas en cuenta en la planificación de las reformas financieras y que, por ello, impiden que las mismas produzcan el impacto esperado.
La creación de institucionalidad financiera como instrumento de desarrollo rural y lucha contra la pobreza
Authors: Bastiaensen Johan
Published: May 2017

La grave crisis institucional que experimenta el área rural de Nicaragua es la que explica que, después de ocho años de paz, con una economía estabilizada y con la tenencia de la tierra más igualitaria en toda la historia del país, aún no se haya producido la reactivación económica y la reducción de la pobreza en el campo. Muchas zonas rurales se encuentran en el "peor de dos mundos": entre la desaparición de los viejos esquemas verticales que regían las transacciones económicas y la aparente imposibilidad de reemplazar estos moldes antiguos por estructuras viables, más mercantiles y cívicas. El autor de este artículo pretende mostrar que la construcción de redes de financiamiento para los pequeños y medianos productores rurales representa una vía para contribuir a la creación de instituciones rurales dinámicas y democratizadoras.
¿Qué enseñan los programas de micro-crédito?
Authors: Ruiz García Alfredo
Published: May 2017

Este artículo pretende aportar evidencias empíricas al debate sobre la relación entre crédito y desarrollo. Sostiene que los programas de micro-crédito no son la panacea para resolver el problema de la pobreza, pero que pueden contribuir a su solución si se ven acompañados de iniciativas de fomento local y si sus características se ajustan, además, a las particularidades de las economías de bajos ingresos. Por otra parte, plantea que el crédito tiene efectos diferenciados que dependen de variables micro-económicas, agro-climáticas y del estrato socioeconómico al que pertenecen los usuarios de los préstamos.