bluuebunny/crossref_metadata_2025 huggingface dataset:
Intervention, Materiality, and Contemporary Somali Counterpiracy
Authors: Jacobsen Katja Lindskov
Published: June 2019

Taking seriously debates in IR about the significance of materiality and noticing the prominence of materiality in contemporary counterpiracy interventions, this article combines insights from Science and Technology Studies (STS) with insights from the poststructuralist intervention literature. Both literatures highlight the importance of “constitutive effects.” Poststructuralists do so with attention to the effects of intervention in constituting, temporarily, the meaning of sovereignty, and STS scholars do so with attention to constitutive effects that processes at the level of materiality give rise to. By combining these two literatures, this article asks: how might we think about the constitutive effects of material aspects of counterpiracy interventions? This question is explored through a focus on two donor-funded pirate prisons in Somalia. By operationalizing the STS notions of coproduction (Jasanoff 2004c) and solution/problem-framings (Beck et al. 2016), the article broadens the study of how intervention practices give rise to constitutive effects by explicitly attending to processes at the level of materiality. This approach enables the article to highlight an important tension in contemporary intervention practices: a tension between donor's desire to delimit intervention contributions and the risk that such contributions (including presumably more easily delineated material aspects) give rise to effects that challenge this faith in neatly delimited forms of intervention. This tension is not only relevant in relation to Somali counterpiracy, but also in other intervention contexts. The article thus illustrates how STS insights can help advance our appreciation of the manifold dimensions and effects of contemporary interventionism.
Primary cutaneous adenoid cystic carcinoma on the lower leg
Authors: Takegawa Masayasu , Kakudo Natsuko , Morimoto Naoki , Hihara Masakatsu , Masuoka Hiromu , Kusumoto Kenji
Published: June 2019

Primary cutaneous adenoid cystic carcinoma (PCACC) is a very rare malignant tumor. Here a case of PCACC on the left lower leg with metastasis to the inguinal lymph node. The tumor resection and the inguinal lymph node dissection were performed under general anesthesia, and the defect was covered with free meshed skin graft. No complication or recurrence has occurred after the surgery.
Traumatic cervical spine injury during sexual activity
Authors: Davidson Caroline , Crutcher Clifford L , Tender Gabriel C
Published: June 2019

Sexual activity is unlikely to result in spinal injuries. We present the first case of a cervical fracture-subluxation and spinal cord injury following sexual activity. This 31-year-old female presented to the emergency room with neck pain and quadriparesis, following sexual activity in an extreme position. Imaging revealed a hyperflexion cervical fracture-subluxation injury, requiring reduction by traction, followed by circumferential surgical fixation. At 6 months postoperatively, she reported baseline return of function. This case demonstrates that sex-induced spinal injuries are possible and may require urgent surgical treatment.
Advantages and disadvantages of 3D printing for pre-operative planning of revision hip surgery
Authors: Tserovski Stefan , Georgieva Simona , Simeonov Radoil , Bigdeli Amir , Röttinger Heinz , Kinov Plamen
Published: June 2019

Total hip arthroplasty (THA) is one of the most successful and cost-effective interventions in medicine nowadays, providing reliable pain relief and functional improvement to those with osteoarthritis or inflammatory arthritis of the hip (P Kinov, B Antonov,’Possibilities for surgical treatment of acetabular osteolysis subsequent to revision arthroplasty of hip joint‘, Orthop Trauma. 52, 2015). Revision hip arthroplasty or severe reconstructive procedures in cases with significant anatomical defects require skilled surgical staff and accurate preoperative planning, including bone insufficiency, deficiency, discontinuity (anatomical assessment) as well as augmentation, cage or other requirements. (implant planning). Some authors recommend preoperative 3D model planning for precise anatomical assessment and preoperative training. This method has some limitations but could be successfully used in addition to conventional surgery.
Keep talking: crosstalk between iron and sulfur networks fine-tunes growth and development to promote survival under iron limitation
Authors: Mendoza-Cózatl David G , Gokul Arun , Carelse Mogamat F , Jobe Timothy O , Long Terri A , Keyster Marshall
Published: June 2019

Plants are capable of synthesizing all the molecules necessary to complete their life cycle from minerals, water, and light. This plasticity, however, comes at a high energetic cost and therefore plants need to regulate their economy and allocate resources accordingly. Iron–sulfur (Fe–S) clusters are at the center of photosynthesis, respiration, amino acid, and DNA metabolism. Fe–S clusters are extraordinary catalysts, but their main components (Fe2+ and S2−) are highly reactive and potentially toxic. To prevent toxicity, plants have evolved mechanisms to regulate the uptake, storage, and assimilation of Fe and S. Recent advances have been made in understanding the cellular economy of Fe and S metabolism individually, and growing evidence suggests that there is dynamic crosstalk between Fe and S networks. In this review, we summarize and discuss recent literature on Fe sensing, allocation, use efficiency, and, when pertinent, its relationship to S metabolism. Our future perspectives include a discussion about the open questions and challenges ahead and how the plant nutrition field can come together to approach these questions in a cohesive and more efficient way.
Doubly disadvantaged? Gender, informal job search, and labor market outcomes among South Korea’s immigrant workers
Authors: Kim Harris Hyun-Soo
Published: June 2019

This research investigates the gendered labor market consequences of immigrant social networks. Based on a nationally representative sample and using alternative analytic strategies, the present study investigates how and the extent to which informal job search, that is, finding a job through a personal contact, is associated with the earnings outcome for male and female immigrant workers in South Korea. Unlike most previous studies, it distinguishes between job contact sources: bonding and bridging. Contrary to the notion that immigrant women are ‘doubly disadvantaged’ in the labor market, findings indicate that informal job search yields lower monthly income for male workers only. In addition, significant evidence suggests that for the male subsample, securing a job through a bonding (co-ethnic) tie results in an earnings penalty. Negative income returns on using a bridging (inter-ethnic) tie, on the other hand, receive conditional empirical support.
Galaxy mass profiles from strong lensing I: the circular power-law model
Authors: O’Riordan C M , Warren S J , Mortlock D J
Published: June 2019

In this series of papers, we develop a formalism for constraining mass profiles in strong gravitational lenses with extended images, using fluxes in addition to positional information. We start in this paper with a circular power-law profile and show that the slope γ is uniquely determined by only two observables: the flux ratio f1/f2 and the image position ratio θ1/θ2 of the two images. We derive an analytic expression relating these two observables to the slope, a result that does not depend on the Einstein angle or the structure or brightness of the source. We then find an expression for the uncertainty on the slope σγ that depends only on the position ratio θ1/θ2 and the total signal-to-noise ratio (S/N) in the images. For example, in a system with position ratio θ1/θ2 = 0.5, S/N = 100, and γ = 2 we find that γ is constrained to a precision of ±0.03. We then test these results against a series of mock observations. We invert the images and fit an 11-parameter model, including ellipticity and position angle for both lens and source and measure the uncertainty on γ. We find agreement with the theoretical estimate for all mock observations. In future papers, we will examine the radial range of the galaxy over which the constraint on the slope applies, and extend the analysis to elliptical lenses.
Partly burnt runaway stellar remnants from peculiar thermonuclear supernovae
Authors: Raddi R , Hollands M A , Koester D , Hermes J J , Gänsicke B T , Heber U , Shen K J , Townsley D M , Pala A F , Reding J S , Toloza O F , Pelisoli I , Geier S , Gentile Fusillo N P , Munari U , Strader J
Published: June 2019

We report the discovery of three stars that, along with the prototype LP 40−365, form a distinct class of chemically peculiar runaway stars that are the survivors of thermonuclear explosions. Spectroscopy of the four confirmed LP 40−365 stars finds ONe-dominated atmospheres enriched with remarkably similar amounts of nuclear ashes of partial O- and Si-burning. Kinematic evidence is consistent with ejection from a binary supernova progenitor; at least two stars have rest-frame velocities indicating they are unbound to the Galaxy. With masses and radii ranging between 0.20 and 0.28 M$\odot$ and between 0.16 and 0.60 R$\odot$, respectively, we speculate these inflated white dwarfs are the partly burnt remnants of either peculiar Type Iax or electron-capture supernovae. Adopting supernova rates from the literature, we estimate that ∼20 LP 40−365 stars brighter than 19 mag should be detectable within 2 kpc from the Sun at the end of the Gaia mission. We suggest that as they cool, these stars will evolve in their spectroscopic appearance, and eventually become peculiar O-rich white dwarfs. Finally, we stress that the discovery of new LP 40−365 stars will be useful to further constrain their evolution, supplying key boundary conditions to the modelling of explosion mechanisms, supernova rates, and nucleosynthetic yields of peculiar thermonuclear explosions.
The luminosity function of quasars by the Principle of Maximum Entropy
Authors: Andrei Alexandre , Coelho Bruno , Guedes Leandro L S , Lyra Alexandre
Published: June 2019

We propose a different way to obtain the distribution of the luminosity function of quasars by using the Principle of Maximum Entropy. The input data come from Richard et al 2006 quasar counts, extending up to redshift 5 and limited from apparent magnitude i = 15–19.1 at z ≲ 3 to i = 20.2 for z ≳ 3. Using only few initial data points, the principle allows us to estimate probabilities and hence that luminosity curve. We carry out statistical tests to evaluate our results. The resulting luminosity function compares well to earlier determinations, and our results remain consistent either when the amount or choice of sampled sources is unbiasedly altered. Besides this, we estimate the distribution of the luminosity function for redshifts in which there is only observational data in the vicinity.
CMB foreground measurements through broad-band radio spectro-polarimetry: prospects of the SKA-MPG telescope
Authors: Basu Aritra , Schwarz Dominik J , Klöckner Hans-Rainer , von Hausegger Sebastian , Kramer Michael , Wieching Gundolf , Burkhart Blakesley
Published: June 2019

Precise measurement of the foreground synchrotron emission, which contaminates the faint polarized cosmic microwave background (CMB) radiation, is a major challenge for the next-generation of CMB experiments. To address this, dedicated foreground measurement experiments are being undertaken at radio frequencies between 2 and 40 GHz. Foreground polarized synchrotron emission measurements are particularly challenging, primarily due to the complicated frequency dependence in the presence of Faraday rotation, and are best recovered through broad fractional-bandwidth polarization measurements at frequencies ≲5 GHz. A unique opportunity for measuring the foreground polarized synchrotron emission will be provided by the 15 m SKA-MPG telescope operating in the frequency range 1.7–3.5 GHz (S band). Here, we present the scope of a Southern-sky survey in S band at 1 deg angular resolution and explore its added advantage for application of powerful techniques, such as, Stokes Q, U fitting and RM-synthesis. A full Southern-sky polarization survey with this telescope, when combined with other on-going efforts at slightly higher frequencies, will provide an excellent frequency coverage for modelling and extrapolating the foreground polarized synchrotron emission to CMB frequencies (≳80 GHz) with rms brightness temperature better than 10 nK per 1 deg2. We find that this survey will be crucial for understanding the effects of Faraday depolarization, especially in low Galactic latitude regions. This will allow better foreground cleaning and thus will contribute significantly in further improving component separation analyses and increase usable sky area for cosmological analysis of the Planck data, and the LiteBIRD mission in the future.
Can we detect aurora in exoplanets orbiting M dwarfs?
Authors: Vidotto A A , Feeney N , Groh J H
Published: June 2019

New instruments and telescopes, such as SPIRou, CARMENES, and Transiting Exoplanet Survey Satellite (TESS), will increase manyfold the number of known planets orbiting M dwarfs. To guide future radio observations, we estimate radio emission from known M dwarf planets using the empirical radiometric prescription derived in the Solar system, in which radio emission is powered by the wind of the host star. Using solar-like wind models, we find that the most promising exoplanets for radio detections are GJ 674 b and Proxima b, followed by YZ Cet b, GJ 1214 b, GJ 436 b. These are the systems that are the closest to us (<10 pc). However, we also show that our radio fluxes are very sensitive to the unknown properties of winds of M dwarfs. So, which types of winds would generate detectable radio emission? In a ‘reverse engineering’ calculation, we show that winds with mass-loss rates $\dot{M} \gtrsim \kappa _{\rm sw} /u_{\rm sw}^3$ would drive planetary radio emission detectable with present-day instruments, where usw is the local stellar wind velocity and κsw is a constant that depends on the size of the planet, distance, and orbital radius. Using observationally constrained properties of the quiescent winds of GJ 436 and Proxima Cen, we conclude that it is unlikely that GJ 436 b and Proxima b would be detectable with present-day radio instruments, unless the host stars generate episodic coronal mass ejections. GJ 674 b, GJ 876 b, and YZ Cet b could present good prospects for radio detection, provided that their host stars’ winds have $\dot{M} u_{\rm sw}^{3} \gtrsim 1.8\times 10^{-4} \, {\rm M}_\odot \,{\rm yr}^{-1}\, ({\rm km\,s^{-1}})^{3}$.
Disparity in Quality of Infectious Disease vs Addiction Care Among Patients With Injection Drug Use–Associated Staphylococcus aureus Bacteremia
Authors: Serota David Phillip , Niehaus Emily D , Schechter Marcos C , Jacob Jesse T , Jones Jeb , Ray Susan M , Kelley Colleen F , Kempker Russell R
Published: June 2019

Evidence-based interventions for Staphylococcus aureus bacteremia (SAB) are well known, but it is unclear how they are implemented among patients with injection drug use–associated (IDU) SAB. Of 46 patients with IDU-SAB identified, all received high-quality SAB management; however, few received appropriate recognition or treatment of their underlying substance use disorder.
Technique for Open Posterior Cervical Foraminotomy: 2-Dimensional Operative Video
Authors: Saadeh Yamaan S , Sabbagh M Amr , Smith Brandon W , Joseph Jacob R , Buckingham Martin J
Published: June 2019

Foraminal stenosis is an important cause of cervical radiculopathy, which can be treated with an anterior or posterior approach, depending on a number of factors. These include the etiology of the foraminal stenosis, individual patient risk factors, and surgeon preference. We provide a step-by-step technique guide for performing an open posterior cervical foraminotomy on a 33-yr-old male with a history of left-sided pain radiating down the medial aspect of his left arm and left triceps weakness. Magnetic resonance imaging demonstrated a left-sided C6-7 disc herniation causing foraminal stenosis. Guidance on positioning, relevant anatomy, and appropriately planning the extent of bony decompression is also provided in this video. The patient, who consented to the recording of this surgical video, tolerated the procedure without complication, and upon follow-up had a significant improvement in his symptoms.
Bilateral Suprascapular Nerve Injury and Novel Technique of Nerve Transfers for Restoration of External Rotation: Case Report
Authors: Abou-Al-Shaar Hussam , Awad Al-Wala , Mahan Mark A
Published: June 2019

BACKGROUND

Complex brachial plexus and peripheral nerve injuries can be challenging to evaluate and treat, especially in the face of novel pathology.

OBJECTIVE

To describe the diagnosis of bilateral suprascapular nerve injury, the unique surgical anatomy, and the novel use of a distal nerve transfer to re-establish external rotation. To the best of our knowledge, bilateral suprascapular nerve injury has not previously been reported.

METHODS

The authors describe the physical examination and electrodiagnostic and imaging work-up for elucidating complex injury patterns and present a procedure for reinnervating the infraspinatus muscle.

RESULTS

A 48-yr-old man presented with profound, right-sided, partial brachial plexus injury incurred 5 mo earlier in a motorcycle accident. Imaging demonstrated atrophy and severe edema within the bilateral supraspinatus and infraspinatus muscles. Needle electromyography depicted no motor units and insertional activities in bilateral infraspinatus muscles, consistent with bilateral suprascapular nerve injury. Along with brachial plexus repair, the patient underwent transfer of a distal branch of the spinal accessory nerve to the inferolateral branch of the suprascapular nerve to the infraspinatus muscle. At 16 mo, he had recovered strong restoration of shoulder external rotation.

CONCLUSION

Systematic evaluation can assist in defining complex pathology, particularly with previously unreported types. In this case, predominant injury was inflicted upon the branch innervating the infraspinatus. Highly focal nerve transfers can achieve substantial restoration of external rotation.
Firm Characteristics, Cross-Sectional Regression Estimates, and Asset Pricing Tests
Authors: Kirby Chris
Published: June 2019

I test a number of well-known asset pricing models using regression-based managed portfolios that capture nonlinearity in the cross-sectional relation between firm characteristics and expected stock returns. Although the average portfolio returns point to substantial nonlinearity in the data, none of the asset pricing models successfully explain the estimated nonlinear effects. Indeed, the estimated expected returns produced by the models display almost no variation across portfolios. Because the tests soundly reject every model considered, it is apparent that nonlinearity in the relation between firm characteristics and expected stock returns poses a formidable challenge to asset pricing theory. (JEL G12, C58)
To Legislate Filial Piety: Is the Elderly Rights Law a Panacea?
Authors: Bu Qingxiu
Published: June 2019

With the life expectancy being steadily increasing, caring for an ageing population presents a paramount challenge in China. The article explores the traditional value of filial piety which is perceived to underpin social norms and beliefs about caring for aged parents. Apart from state and social institutions, a particular regard is given to the reshaping of relationships between aged persons and their family members. Given filial piety being a core value in Chinese cultures, there is a societal interest in protecting a healthy relationship between parents and children in the twenty-first century. In terms of the relational dimensions of current theories, it remains unclear whether an individual rights-based approach would have traction in the Chinese context, or represents an unintended disseverance from the Chinese traditional core values. More critically, a new law requires adult children to visit their elderly parents regularly. With the ongoing attempts to theorize and reconceptualize elder law across jurisdictions, the research further examines emerging legal issues that have arisen in China, and seeks to ascertain the extent to which the law addresses the above inquiry.
The effect of using a project-based learning (PBL) approach to improve engineering students’ understanding of statistics
Authors: Farrell Fionnuala , Carr Michael
Published: June 2019

Over the last number of years we have gradually been introducing a project based learning approach to the teaching of engineering mathematics in Dublin Institute of Technology. Several projects are now in existence for the teaching of both second-order differential equations and first order differential equations. We intend to incrementally extend this approach across more of the engineering mathematics curriculum. As part of this ongoing process, practical real-world projects in statistics were incorporated into a second year ordinary degree mathematics module. This paper provides an overview of these projects and their implementation. As a means to measure the success of this initiative, we used the SALG instrument to gain feedback from the students. The SALG online tool - Student Assessment of their Learning Gains - https://salgsite.net/; is a free course-evaluation tool that enables third-level educators to gather feedback specifically focused on what the students gained through the learning exercise they experience. It can be used to measure students’ learning gains. Pre-developed surveys are available which can be modified and are stored in a repository for ease of access. Results are anonymous and there is the ability to download comments and basic statistical analysis of responses. Feedback from the survey points to a large increase in understanding of the material coupled with an increase in confidence. In addition we outline some of the limitations of our initial implementation of this approach and what we hope to improve on for the next academic year.
Xylella fastidiosaEndoglucanases Mediate the Rate of Pierce’s Disease Development inVitis viniferain a Cultivar-Dependent Manner
Authors: Ingel Brian , Jeske Daniel R. , Sun Qiang , Grosskopf Joseph , Roper M. Caroline
Published: June 2019

Xylella fastidiosa is a gram-negative bacterium that causes Pierce’s disease (PD) in grapevine. X. fastidiosa is xylem-limited and interfaces primarily with pit membranes (PMs) that separate xylem vessels from one another and from adjacent xylem parenchyma cells. PMs are composed of both pectic and cellulosic substrates, and dissolution of PMs is facilitated by X. fastidiosa cell wall-degrading enzymes. A polygalacturonase, which hydrolyzes the pectin component of PMs, is required for both movement and pathogenicity in grapevines. Here, we demonstrate that two X. fastidiosa β-1,4-endoglucanases (EGases), EngXCA1 and EngXCA2, also play a role in how X. fastidiosa interfaces with grapevine PMs. The loss of EngXCA1 and EngXCA2 in tandem reduces both X. fastidiosa virulence and population size and slows the rate of PD symptom development and progression. Moreover, we demonstrate that single and double EGases mutants alter the rate of PD progression differently in two grapevine cultivars, Cabernet Sauvignon and Chardonnay, and that Chardonnay is significantly more susceptible to PD than Cabernet Sauvignon. Interestingly, we determined that there are quantitative differences in the amount of fucosylated xyloglucans that make up the surface of PMs in these cultivars. Fucosylated xyloglucans are targets of the X. fastidiosa EGases, and xyloglucan abundance could impact PM dissolution and affect PD symptom development. Taken together, these results indicate that X. fastidiosa EGases and the PM carbohydrate composition of different grape cultivars are important factors that influence PD symptom development and progression.
‘Sneezing’ plants: pathogen transport via jumping-droplet condensation
Authors: Nath Saurabh , Ahmadi S. Farzad , Gruszewski Hope A. , Budhiraja Stuti , Bisbano Caitlin E. , Jung Sunghwan , Schmale David G. , Boreyko Jonathan B.
Published: June 2019

We show that condensation growing on wheat leaves infected with the leaf rust fungus,
Puccinia triticina
, is capable of spontaneously launching urediniospores off the plant. This surprising liberation mechanism is enabled by the superhydrophobicity of wheat leaves, which promotes a jumping-droplet mode of condensation powered by the surface energy released from coalescence events. We found that urediniospores often adhere to the self-propelled condensate, resulting in liberation rates of approximately 10 cm
−2
h
−1
for leaves infected with rust. Urediniospores were catapulted up to 5 mm from the leaf’s surface, a distance sufficient to clear the laminar boundary layer for subsequent dispersal even in gentle winds.
Tales of tails in transporters
Authors: Mikros Emmanuel , Diallinas George
Published: June 2019

Cell nutrition, detoxification, signalling, homeostasis and response to drugs, processes related to cell growth, differentiation and survival are all mediated by plasma membrane (PM) proteins called transporters. Despite their distinct fine structures, mechanism of function, energetic requirements, kinetics and substrate specificities, all transporters are characterized by a main hydrophobic body embedded in the PM as a series of tightly packed, often intertwined, α-helices that traverse the lipid bilayer in a zigzag mode, connected with intracellular or extracellular loops and hydrophilic N- and C-termini. Whereas longstanding genetic, biochemical and biophysical evidence suggests that specific transmembrane segments, and also their connecting loops, are responsible for substrate recognition and transport dynamics, emerging evidence also reveals the functional importance of transporter N- and C-termini, in respect to transport catalysis, substrate specificity, subcellular expression, stability and signalling. This review highlights selected prototypic examples of transporters in which their termini play important roles in their functioning.
RNA–protein interactions: disorder, moonlighting and junk contribute to eukaryotic complexity
Authors: Balcerak Anna , Trebinska-Stryjewska Alicja , Konopinski Ryszard , Wakula Maciej , Grzybowska Ewa Anna
Published: June 2019

RNA–protein interactions are crucial for most biological processes in all organisms. However, it appears that the complexity of RNA-based regulation increases with the complexity of the organism, creating additional regulatory circuits, the scope of which is only now being revealed. It is becoming apparent that previously unappreciated features, such as disordered structural regions in proteins or non-coding regions in DNA leading to higher plasticity and pliability in RNA–protein complexes, are in fact essential for complex, precise and fine-tuned regulation. This review addresses the issue of the role of RNA–protein interactions in generating eukaryotic complexity, focusing on the newly characterized disordered RNA-binding motifs, moonlighting of metabolic enzymes, RNA-binding proteins interactions with different RNA species and their participation in regulatory networks of higher order.
Ninety years of change on a low wooded island, Great Barrier Reef
Authors: Hamylton S. M. , McLean R. , Lowe M. , Adnan F. A. F.
Published: June 2019

We assess 90 years of change on a Low Wooded Island (Low Isles, Great Barrier Reef), employing drones and topographic profiling to accurately survey ramparts, mangroves, the reef flat and the sand cay. A comparison with maps from the 1928–1929 Great Barrier Reef Expedition revealed the redistribution of an outer rampart and inward movement of shingle ridges. Remarkable lateral expansion of the mangrove woodland some 400 m has occurred as carbonate sand deposition has increased reef flat elevation, obscuring coral microatolls. The sand cay has stayed relatively constant in size, moving approximately 44 m in a northeasterly direction and rotating slightly. We conclude that the existing configuration of landforms probably represents an equilibrium with local biophysical conditions, including sea level, wave dynamics, vegetation growth, storms and cyclones. The variable nature of ramparts and the presence of a trough that prevents the continuous spread of mangroves across a uniformly flat colonization surface precludes the interpretation of landform changes with respect to a geomorphic evolutionary sequence. Moreover, longer-term implications of environmental change for these landforms can only be evaluated once the specific nature of the local carbonate budget, including the relative contribution of corals, foraminifera and
Halimeda
has been elucidated.
A new loading–unloading experimental method for simulating the change of mining-induced stress
Authors: Jiang Changbao , Liu Xiaodong , Li Minghui , Yu Huan , Duan Minke
Published: June 2019

Based on a self-developed triaxial seepage device, a new loading and unloading experimental method is proposed in this paper to eliminate sample variations. The results show that the strength of sandstone sample and the axial strain at failure increased with the increasing initial hydrostatic stress, but decreased with the increasing loading–unloading rate. Following the alternating loading–unloading test, the stress–strain curves of specimens advanced in wave form, the waves' volatility decreased and then increased. It is found that near the ultimate strength, volatility is the biggest, and the stability of waves’ volatility increased along with the increasing initial hydrostatic stress. The similarity of stress–strain curves between the conventional loading–unloading tests and the alternating loading–unloading tests increased along with the increasing initial hydrostatic stress and the increasing initial velocity for the alternating loading–unloading method. Along with the increasing initial hydrostatic stress, the failure behaviour of the sandstone samples tested under loading–unloading methods changed from a tensile state to a tensile-shear coexisting state, and finally to a fully shear failure state. The degree of failure modes increased with the increasing loading–unloading rate.
Lubrication model of suspension flow in a hydraulic fracture with frictional rheology for shear-induced migration and jamming
Authors: Dontsov E. V. , Boronin S. A. , Osiptsov A. A. , Derbyshev D. Yu.
Published: June 2019

We developed a model for suspension flow in a hydraulic fracture, taking into account frictional rheology to capture the effects of shear-induced particle migration, jamming and transition to close packing. One of the key issues with the existing slurry rheology models is that each of them diverges near the close packing limit, which is typically resolved in numerical simulations via a pragmatic (and mostly unjustified) regularization. Another drawback of the family of existing models for proppant transport in fractures is the assumption of a uniform cross-flow concentration profile, which neglects the effects of shear-induced migration. We developed a self-consistent model for slurry flow with a constitutive relation for suspension rheology, which is applicable in the entire range of particle volume concentration, from dilute suspension through dense suspension to the close packing limit. In addition, we investigated the influence of various constitutive relations for the suspension rheology on the final model for the slurry flow. The selected model for slurry flow was implemented into a two-dimensional lubrication model of proppant transport in a fracture (based on the two-continua approach), and illustrative simulations were conducted in comparison with the family of existing suspension rheology models (having a singularity). Validation against laboratory experiments is discussed.
Mathematical modelling for sustainable aphid control in agriculture via intercropping
Authors: Allen-Perkins Alfonso , Estrada Ernesto
Published: June 2019

Agricultural losses to pests represent an important challenge in a global warming scenario. Intercropping is an alternative farming practice that promotes pest control without the use of chemical pesticides. Here, we develop a mathematical model to study epidemic spreading and control in intercropped agricultural fields as a sustainable pest management tool for agriculture. The model combines the movement of aphids transmitting a virus in an agricultural field, the spatial distribution of plants in the intercropped field and the presence of ‘trap crops’ in an epidemiological susceptible–infected–removed model. Using this model, we study several intercropping arrangements without and with trap crops and find a new intercropping arrangement that may improve significantly pest management in agricultural fields with respect to the commonly used intercrop systems.
A rock-boring and rock-ingesting freshwater bivalve (shipworm) from the Philippines
Authors: Shipway J. Reuben , Altamia Marvin A. , Rosenberg Gary , Concepcion Gisela P. , Haygood Margo G. , Distel Daniel L.
Published: June 2019

Shipworms are a group of wood-boring and wood-feeding bivalves of extraordinary economic, ecological and historical importance. Known in the literature since the fourth century BC, shipworms are both destructive pests and critical providers of ecosystem services. All previously described shipworms are obligate wood-borers, completing all or part of their life cycle in wood and most are thought to use wood as a primary source of nutrition. Here, we report and describe a new anatomically and morphologically divergent species of shipworm that bores in carbonate limestone rather than in woody substrates and lacks adaptations associated with wood-boring and wood digestion. The species is highly unusual in that it bores by ingesting rock and is among the very few known freshwater rock-boring macrobioeroders. The calcareous burrow linings of this species resemble fossil borings normally associated with bivalve bioerosion of wood substrates (ichnospecies
Teredolites longissimus
) in marginal and fully marine settings. The occurrence of this newly recognized shipworm in a lithic substrate has implications for teredinid phylogeny and evolution, and interpreting palaeoenvironmental conditions based on fossil bioerosion features.
Anthropogenic remediation of heavy metals selects against natural microbial remediation
Authors: Hesse Elze , Padfield Daniel , Bayer Florian , van Veen Eleanor M. , Bryan Christopher G. , Buckling Angus
Published: June 2019

In an era of unprecedented environmental change, there have been increasing ecological and global public health concerns associated with exposure to anthropogenic pollutants. While there is a pressing need to remediate polluted ecosystems, human intervention might unwittingly oppose selection for natural detoxification, which is primarily carried out by microbes. We test this possibility in the context of a ubiquitous chemical remediation strategy aimed at targeting metal pollution: the addition of lime-containing materials. Here, we show that raising pH by liming decreased the availability of toxic metals in acidic mine-degraded soils, but as a consequence selected against microbial taxa that naturally remediate soil through the production of metal-binding siderophores. Our results therefore highlight the crucial need to consider the eco-evolutionary consequences of human environmental strategies on microbial ecosystem services and other traits.
Enterohaemorrhagic Escherichia coli O121:H19 acquired an extended-spectrum β-lactamase gene during the development of an outbreak in two nurseries
Authors: Kikuchi Koji , Lee Kenichi , Ueno Hiroyuki , Tomari Kentaro , Kobori Sumie , Kaetsu Akihiko , Matsui Mari , Suzuki Satowa , Sekizuka Tsuyoshi , Kuroda Makoto , Miyazaki Motonobu , Ohnishi Makoto
Published: June 2019

EnterohaemorrhagicEscherichia coli(EHEC) is an important human pathogen worldwide. Although serotype O157 is currently the most dominant and important EHEC strain, serotypes O26, O111, O91, O103 and O121 are also recognized as serious pathogens that affect public health. EHEC outbreaks often occur in nurseries and elderly care facilities. In 2012, a nursery outbreak of EHEC O121 occurred during which the bacterium acquired a plasmid-borne extended-spectrumβ-lactamase (ESBL) gene. ESBL-producingE. coliO86 was concurrently isolated from one of the EHEC patients. Therefore, we investigated the isolates by whole-genome sequence (WGS) analysis to elucidate the transmission dynamics of the EHEC strains and the ESBL plasmid. According to WGS-based phylogeny, all 17 EHEC O121 isolates were clonal, whileE. coliO86 was genetically distant from the EHEC O121 isolates. The complete sequence of an ESBL plasmid encoding the CTX-M-55β-lactamase was determined using S1-PFGE bands, and subsequent mapping of the WGS reads confirmed that the plasmid sequences from EHEC O121 andE. coliO86 were identical. Furthermore, conjugation experiments showed that the plasmid was capable of conjugative transfer. These results support the hypothesis that EHEC O121 acquired an ESBL-producing plasmid fromE. coliO86 during the outbreak. This report demonstrates the importance of implementing preventive measures during EHEC outbreaks to control both secondary infection and the spread of antimicrobial resistance factors.
Unsuspected involvement of spinal cord in Alzheimer Disease
Authors: Lorenzi Roberta Maria , Palesi Fulvia , Castellazzi Gloria , Vitali Paolo , Anzalone Nicoletta , Bernini Sara , Sinforiani Elena , Micieli Giuseppe , Costa Alfredo , D’Angelo Egidio , Gandini Wheeler-Kingshott Claudia A.M.
Published: June 2019

Objective

Brain atrophy is an established biomarker for dementia, yet spinal cord involvement has not been investigated to date. As the spinal cord is relaying sensorimotor control signals from the cortex to the peripheral nervous system and viceversa, it is indeed a very interesting question to assess whether it is affected by atrophy in a disease that is known for its involvement of cognitive domains first and foremost, with motor symptoms being clinically assessed too. We therefore hypothesize that Alzheimer Disease severe atrophy can affect the spinal cord too and that spinal cord atrophy is indeed an important in vivo imaging biomarker contributing to understanding neurodegeneration associated with dementia.

Methods

3DT1 images of 31 Alzheimer’s disease (AD) and 35 healthy control (HC) subjects were processed to calculate volumes of brain structures and cross-sectional area (CSA) and volume (CSV) of the cervical cord (per vertebra as well as the C2-C3 pair (CSA23 and CSV23)). Correlated features (ρ>0.7) were removed, and best subset identified for patients’ classification with the Random Forest algorithm. General linear model regression was used to find significant differences between groups (p<=0.05). Linear regression was implemented to assess the explained variance of the Mini Mental State Examination (MMSE) score as dependent variable with best features as predictors.

Results

Spinal cord features were significantly reduced in AD, independently of brain volumes. Patients classification reached 76% accuracy when including CSA23 together with volumes of hippocampi, left amygdala, white and grey matter, with 74% sensitivity and 78% specificity. CSA23 alone explained 13% of MMSE variance.

Discussion

Our findings reveal that C2-C3 spinal cord atrophy contributes to discriminate AD from HC, together with more established features. Results show that CSA23, calculated form the same 3DT1 scan as all other brain volumes (including right and left hippocampi), has a considerable weight in classification tasks warranting further investigations. Together with recent studies revealing that AD atrophy is spread beyond the temporal lobes, our result adds the spinal cord to a number of unsuspected regions involved in the disease. Interestingly, spinal cord atrophy explains also cognitive scores, which could significantly impact how we model sensorimotor control in degenerative diseases with a primary cognitive domain involvement. Prospective studies should be purposely designed to understand the mechanisms of atrophy and the role of the spinal cord in AD.
Mendelian randomization indicates that TNF is not causally associated with Alzheimer’s disease
Authors: Andrews Shea J , Goate Alison
Published: June 2019

INTRODUCTION

Epidemiological research has suggested that inhibition of tumor necrosis factor (TNF)-α in patients with rheumatoid arthritis (RA) reduces the overall risk of Alzheimer’s disease (AD). TNF-α antagonists have been suggested as a potential treatment for AD.

METHODS

We used a two-sample Mendelian randomization design to examine the causal relationship between blood TNF expression, serum TNF-α levels, and RA on AD risk.

RESULTS

Our results do not support a causal relationship between TNF expression, serum TNF-α levels or RA on AD risk.

DISCUSSION

These results suggest that TNF-α antagonists are unlikely to reduce the risk of AD.
Theyellowgene influencesDrosophilamale mating success through sex comb melanization
Authors: Massey Jonathan H. , Chung Daayun , Siwanowicz Igor , Stern David L. , Wittkopp Patricia J.
Published: June 2019

Drosophila melanogastermales perform a series of courtship behaviors that, when successful, result in copulation with a female. For over a century, mutations in theyellowgene, named for its effects on pigmentation, have been known to reduce male mating success. Prior work has suggested thatyellowinfluences mating behavior through effects on wing extension, song, and/or courtship vigor. Here, we rule out these explanations, as well as effects on the nervous system more generally, and find instead that the effects ofyellowon male mating success are mediated by its effects on pigmentation of male-specific leg structures called sex combs. Loss ofyellowexpression in these modified bristles reduces their melanization, which changes their structure and causes difficulty grasping females prior to copulation. These data illustrate why the mechanical properties of anatomy, and not just neural circuitry, must be considered to fully understand the development and evolution of behavior.
Rapid range shifts in AfricanAnophelesmosquitoes over the last century
Authors: Carlson Colin J. , Bannon Ellen , Mendenhall Emily , Newfield Timothy , Bansal Shweta
Published: June 2019

Facing a warming climate, many tropical species-including the arthropod vectors of several infectious diseases-will be displaced to higher latitudes and elevations. These shifts are frequently forecasted for the future, but rarely documented in the present day. Here, we use one of the most comprehensive datasets ever compiled by medical entomologists to track the observed range limits of African malaria mosquito vectors (Anophelesspp.) from 1898 to 2016. Using a simple regression approach, we estimate that these species’ ranges gained an average of 6.5 meters of elevation per year, and the southern limits of their ranges moved polewards 4.7 kilometers per year. These shifts are consistent with the local velocity of climate change, and might help explain the incursion of malaria transmission into new areas over the past few decades. Confirming that climate change underlies these shifts, and applying similar methods to other disease vectors, are important directions for future research.
Phylogeny ofPaulliniaL. (Paullinieae: Sapindaceae), a diverse genus of lianas with rapid fruit evolution
Authors: Chery Joyce G. , Acevedo-Rodríguez Pedro , Rothfels Carl J , Specht Chelsea D.
Published: June 2019

PaulliniaL. is a genus of c. 220 mostly Neotropical forest-dwelling lianas that displays a wide diversity of fruit morphologies.Paulliniaresembles other members of the Paullinieae in being a climber with stipulate compound leaves and paired inflorescence tendrils. However, it is distinct in having capsular fruits with woody, coriaceous, or crustaceous pericarps. While consistent in this basic plan, the pericarps ofPaulliniafruits are otherwise highly variable—in some species they are winged, whereas in others they are without wings or covered with spines. With the exception of the water-dispersed indehiscent spiny fruits of some members ofPaulliniasect.Castanella, all species are dehiscent, opening their capsules while they are still attached to the branch, to reveal arillate animal-dispersed seeds. Here we present a molecular phylogeny ofPaulliniaderived from 11 molecular markers, including nine novel single-copy nuclear markers amplified by microfluidics PCR. This is the first broadly sampled molecular phylogeny for the genus.Paulliniais supported as monophyletic and is sister toCardiospermumL., which together are sister toSerjaniaMill +UrvilleaKunth. We apply this novel phylogenetic hypothesis to test previous infrageneric classifications and to infer that unwinged fruits represent the ancestral condition, from which there were repeated evolutionary transitions and reversals. However, because the seeds of both winged and unwinged fruits are all dispersed by animals, we conclude that the repeated transitions in fruit morphology may relate to visual display strategies to attract animal dispersers, and do not represent transitions to wind dispersal.
A Genome Model Linking Birth Defects to Infections
Authors: Friedenson Bernard
Published: June 2019

The purpose of this study was to test the hypothesis that infections are linked to chromosomal anomalies that cause neurodevelopmental disorders. In children with disorders in the development of their nervous systems, chromosome anomalies known to cause these disorders were compared to microbial DNA, including known teratogens. Genes essential for neurons, lymphatic drainage, immunity, circulation, angiogenesis, cell barriers, structure, epigenetic and chromatin modifications were all found close together in polyfunctional clusters that were deleted or rearranged in neurodevelopmental disorders. In some patients, epigenetic driver mutations also changed access to large chromosome segments. These changes account for immune, circulatory, and structural deficits that accompany neurologic deficits. Specific and repetitive human DNA encompassing large deletions matched infections and passed rigorous artifact tests. Deletions of up to millions of bases accompanied infection-matching sequences and caused massive changes in the homologies to foreign DNAs. In data from three independent studies of private, familial and recurrent chromosomal rearrangements, massive changes in homologous microbiomes were found and may drive rearrangements and encourage pathogens. At least one chromosomal anomaly was found to consist of human DNA fragments with a gap that corresponded to a piece of integrated foreign DNA. Microbial DNAs that match repetitive or specific human DNA segments are thus proposed to interfere with the epigenome and highly active recombination during meiosis, driven by massive changes in the homologous microbiome. Abnormal recombination in gametes produces zygotes containing rare chromosome anomalies which cause neurologic disorders and non-neurologic signs. Neurodevelopmental disorders may be examples of assault on the human genome by foreign DNA at a critical stage. Some infections may be more likely tolerated because they resemble human DNA segments. Further tests of this model await new technology.

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