bluuebunny/crossref_metadata_2025 huggingface dataset:
Hemicelluloses and associated compounds determine gall functional traits
Authors: Bragança G. P. P. , Alencar C. F. , Freitas M. S. C. , Isaias R. M. S.
Published: June 2020

The intriguing questions concerning gall development refer to the processes of the remodelling of the host plant organ. Such processes involve the restructuring of cell walls and can be influenced by phenolics, indole‐3‐acetic acid (IAA) and reactive oxygen species (ROS). Alterations in cell walls demand the interference in the coupling of cellulose fibrils and hemicelluloses (xyloglucans) at specific stages of gall development. In addition to cell wall remodelling, hemicelluloses, such as the, xyloglucans and heteromannans can act as reserve carbohydrates, while xylans provide rigidity to the secondary cell walls.

Developmental traits of the lenticular, fusiform and globoid galls onInga ingoides(Fabaceae) were analysed using anatomical, cytometric, histochemical and immunocytochemical tools.

Phenolics, IAA and ROS accumulated in similar gall tissue compartments, and may have influenced the restructuring of hemicelluloses and pectins. Contrary to expectations, cell wall flexibility regarding the dynamics of xyloglucans and cellulose fibrils does not relate to a temporal scale. The detection of xyloglucans in nutritive cell walls relate to carbohydrate nutritional resources to the galling insect, while xylans were associated to the lignified cell walls. Heteromanans were not detected, either in non‐galled or galled tissues.

The patterns of cell expansion during gall development relied on the relationship among phenolics, ROS and IAA with the hemicelluloses (xyloglucans and xylans) and cellulose fibrils. Although cell wall dynamics is specific to each gall morphotype inI. ingoides, the xyloglucans function as carbohydrate reserve to the gall inducers, which constitutes a functional trait common to the three morphotypes.
Parasympathetic and sympathetic nervous systems interactively predict change in cognitive functioning in midlife adults
Authors: Knight Erik L. , Giuliano Ryan J. , Shank Sean W. , Clarke Megan M. , Almeida David M.
Published: June 2020

The two branches of the autonomic nervous system (ANS) have been individually linked to changes in cognitive functioning: The parasympathetic nervous system (PNS) has been associated with healthy cognitive aging, whereas excessive sympathetic nervous system (SNS) activity has been linked to heightened cognitive decline. Despite these separate findings and despite the integrative nature of the ANS, little work has examined the two branches simultaneously to better understand their interactive effects on changes in cognitive functioning in midlife adults. We examined cognitive change in two waves of the Midlife in the United States (MIDUS) study cognitive project and indexed PNS and SNS activity from heart rate variability and epinephrine levels, respectively, from the MIDUS biomarker project (minimum n = 843, 57.9% female, mean age at first wave = 53.8 years). Our findings indicate that greater PNS responsivity (i.e., greater withdrawal and greater recovery) in response to cognitive challenge is associated with attenuated cognitive decline, but only among individuals with low SNS levels; at higher SNS levels, the effects of the PNS on cognitive decline are attenuated. These results suggest that future research targeting the ANS and cognitive aging should consider both ANS branch's effects simultaneously.
The Demise of the Overhead Myth: Administrative Capacity and Financial Sustainability in Nonprofit Nursing Homes
Authors: Park Young Joo , Matkin David S.T.
Published: June 2020

In the study and practice of public administration, it is often assumed that higher levels of budgetary support for non‐program expenses, such as administrator salaries, accounting, grant writing, and marketing, are evidence of inefficiency and wasteful spending. As such, grant makers and researchers often use the ratio of organizations’ administrative to total costs to measure the efficiency of public services. While this perspective has some validity, it also significantly minimizes the effect of administrative functions on sustainability, an important aspect of long‐term performance in public service organizations. We use standardized cost data from a 14‐year panel of approximately 3,000 nonprofit nursing homes and find an inverted U‐shaped relationship between administrative cost ratios and financial sustainability, which suggests a “sweet spot” in the level of administrative support that tends to promote organizational sustainability. This sweet spot occurs when administrative costs are about 40 percent of total organizational costs.
The necessity of antioxidant inclusion in caprine and ovine semen extenders: A systematic review complemented with computational insight
Authors: Moradi Mojtaba , Karimi Isaac , Ahmadi Shirin , Mohammed Layth J.
Published: June 2020

The inclusion of antioxidants (AOXs) has been proposed in various protocols to conserve the normal physiology of spermatozoa during (cryo) preservation. The main aim of this review was to understand the necessity of AOXs inclusion in semen extenders of caprine and ovine semen samples and to decipher physico‐chemical space of AOXs used in semen extenders till now. A total 27 full‐text relevant articles were finally discussed here. This systematic review showed that the inclusion of AOXs may improve the success of semen cryopreservation although at least three studies could not support this finding. AOXs have been not added after assaying total antioxidant capacity of the sample of interest, and this is principal measurement bias of all papers. Furthermore, no rational dose–response curve and precise posology have been considered in comparable studies. Furthermore, new methodologies are requested to detect the oxidative status of semen specimens before AXOs fortification and new methodologies like imaging are also needed to detect various injuries of sperms during semen (cryo)preservation. Defining computational chemical and physical spaces of AOXs which used in semen (cryo)preservation would be an interdisciplinary effort to hasten deciphering epoch‐making compounds. In conclusion, more in‐depth analytical, toxicological and pharmacological methodologies should be pursued in supplementation or addition of AOXs during caprine and ovine semen (cryo)preservation after determining the oxidative status of semen samples.
Posh but Poor: The Association Between Relative Socio‐Economic Status and Children’s Academic Performance
Authors: Jerrim John , Lopez‐Agudo Luis Alejandro , Marcenaro‐Gutierrez Oscar David
Published: June 2020

It is well known that young people from more advantaged socio‐economic backgrounds have, on average, higher levels of academic achievement than their disadvantaged peers. Yet rather less is known about how the relative socio‐economic position of students might be related to their academic progression at school. This is the issue considered in this paper, using longitudinal administrative data covering the largest region within Spain. We find evidence that the relative socio‐economic position of students within their school is associated with grade retention, performance in standardized tests and attitudes towards school, even after controlling for the absolute level of their socio‐economic status. Our primary conclusion is that both absolute and relative social position matters for young people’s academic development.
Do Foreign Firms Transfer Gender Norms in the Labour Market? Evidence from Sub‐Saharan Africa
Authors: Hoxhaj Rezart , Miti Florian
Published: June 2020

Closing the gender gaps in economic opportunities is crucial for boosting economic growth and the empowerment of women. In this paper, we study how foreign firms contribute in reducing gender disparities in the labour market by transferring the gender norms of their country of origin to the affiliates in the host countries. We use cross sectional data on foreign firms located in 19 Sub Saharan Africa countries in 2010 by UNIDO. We find that firms coming from more gender equal countries employ more female workers in their affiliates. This effect is more relevant for the highly skilled female workers.
Outcomes after transfer from hemodialysis to peritoneal dialysis vs peritoneal dialysis as initial therapy: A systematic review and meta‐analysis
Authors: Wang Jin , Zeng Jianhui , Liu Bin , Cai Baolan , Li Yanlin , Dong Lijuan
Published: June 2020

Outcomes of patients who are transferred to peritoneal dialysis (PD) after an initial phase of hemodialysis (HD) compared to patients initiating dialysis with PD is controversial. We performed a systematic literature to assess evidence. Primary outcome was overall survival (OS), while secondary outcomes were technique failure, mortality and peritonitis. Meta‐analysis indicated that PD initial group had significantly better OS as compared to HD to PD group. Pooled analysis demonstrated a significantly higher probability of technique failure in the HD to PD group as compared to PD initial group. Mortality rate in HD to PD group was significantly higher but there was no statistically significant difference in peritonitis rates between the two groups. On meta‐regression analysis, transfer from HD to PD due to vascular access problems was associated with significantly reduced probability of OS. Our study indicates that patients transferred from HD to PD after at least 3 months of HD therapy may have reduced OS as compared to patients initiating dialysis with PD. Our findings lend some support to PD first policy and the need for heightened vigilance among the switched patients to monitor for adverse events.
Semiparametric estimation with spatially correlated recurrent events
Authors: Adekpedjou Akim , Dabo‐Niang Sophie
Published: June 2020

This article pertains to the analysis of recurrent event data in the presence of spatial correlation. Consider units located at n possibly spatially correlated geographical areas described by their longitude and latitude and monitored for the occurrence of an event that can recur. We propose a new class of semiparametric models for recurrent events that simultaneously account for risk factors and correlation among the spatial locations, and that subsumes the current methods. Since the parameters involved in the models are not directly estimable because of the high dimension of the likelihood, we use composite likelihood approach for estimation. The approach leads to estimates with population interpretation where their large sample properties are obtained under a reasonable set of regularity conditions. Simulation studies suggest that the resulting estimators have a very good finite sampling properties. The methods are illustrated using spatial data on recurrent esophageal cancer in the northern region of France and recurrent wildfire data in the province of Alberta, Canada.
Portfolio Management on an Emerging Market: Dynamic Strategy or Passive Strategy?
Authors: BAMA Pourakin Djarius Dieudonné
Published: June 2020

At first glance, the portfolio management strategy seems like a resolved question, but practitioners continue to perform poorly on the stock markets. This paper highlights the portfolio management in the specific case of the West African regional stock exchange, regarding two management strategies. These are dynamic strategy and passive strategy. Within this framework, we will compare an investor who is constantly betting on price fluctuations with another who is betting on dividends. Its originality lies in the approach that is used. Through a simulation methodology based on real market data, the main results indicate that an emerging market is a savings market more than it is a speculation market. Besides, other results indicate that, one can predict on the West African regional stock exchange tomorrow’s prices from today’s prices. This does not mean that investors are making good predictions because the predictability of prices is due to the absence of changes in asset prices on the market. We draw the conclusion that it is difficult for one speculator to outperform the other. A rational investor would benefit from anticipating the distribution of dividends rather than focusing on price fluctuations. Consequently, the buy and hold strategy is therefore the best to be rewarded in an emerging market. Nonetheless, this practice can lead to a decline in liquidity.
Research on Mental Health of Postgraduates in F University in China
Authors: Wan Dongfang , Zhou Yasong
Published: June 2020

This study investigates the mental health of 291 postgraduates in F University in China through Symptom Checklist-90 (known as SCL-90). The results show that 43.97% of the postgraduates suffer mental health problems of varying degrees, and a larger proportion of them are confronted with mild mental problems. The findings also reveal that the postgraduates score greatly higher than the SCL-90 National Norm of Chinese Adults in the four factors of compulsion, anxiety, terror and mental illness symptoms, while the two factors of interpersonal sensitivity and hostility are significantly lower. Besides, female postgraduates, English-related postgraduates and postgraduates from rural areas, whose mental health are worse, may be under greater pressure. This study would shed light on the relevant basis for further improvement of the postgraduates’ mental health, and the corresponding countermeasures and suggestions for colleges and universities.
De geografías del riesgo a riesgos territorializados. Un abordaje multinivel como apuesta ante la esencialización del riesgo y los territorios en salud pública
Authors: Muñoz Duque Luz Adriana , Restrepo Ochoa Diego Alveiro , Agudelo Cadavid Ruth Marina , Navarro Carrascal Óscar E.
Published: June 2020

En el marco de la salud pública pueden observarse distintas formas de pensar la categoría territorio y su asociación con ciertos resultados y respuestas sociales en salud. El territorio ha sido entendido como división administrativa, como un continente o receptáculo de riesgos, como generador de amenazas, o el cual, en interacción con características de los individuos, da lugar a unas ciertas consecuencias en salud. Dado el privilegio de miradas reducidas, tanto del riesgo en salud —en una acepción principalmente probabilística—, como del territorio, ha de ampliarse la comprensión sobre la relación territorio-riesgo-salud, vía en la cual se propone un pasaje de la idea de geografías del riesgo, al abordaje de riesgos territorializados, en una apuesta por lograr análisis situados del riesgo, que no desconozcan dimensiones contextuales, y en una perspectiva escalar que involucra distintos lugares de enunciación. Los planteamientos son ilustrados a partir del caso de la minería en Colombia.
Modelo de simulación sistémica para el dimensionamiento de camas hospitalarias en una institución de salud de alta complejidad utilizando la metodología de dinámica de sistemas
Authors: Uribe Gómez Julian Alberto , Barrientos Gómez Juan Guillermo
Published: June 2020

Las clínicas, hospitales y centros de salud se encuentran diariamente en la necesidad de optimizar sus recursos profesionales, farmacéuticos, hospitalarios o de infraestructura mobiliaria, sin embargo, debido a múltiples factores aleatorios y complejos, la labor se torna demandante, por la falta de metodologías que ayuden a los gestores de salud a controlar las necesidades del proceso. A partir de todo esto, el objetivo es desarrollar una metodología sistémica y un modelo de planificación para el dimensionamiento de la cama hospitalaria, con el fin de mejorar la planeación y administración en una institución de salud. Inicialmente, se realizó una búsqueda de factores claves que afectan la planeación, las relaciones y componentes en la medición de las camas. Con esto se planteó un modelo causal y uno de simulación mediante dinámica de sistemas, que integre dichos factores. Finalmente, los resultados de la simulación indican que la necesidad de camas adicionales para la institución es del 9% o 16 camas hospitalarias en promedio. Se espera que el concepto presentado brinde una idea clara, holística y consecuente en la planeación de recursos hospitalarios.
Las promotoras rurales de salud: una práctica social en extinción. Estudio de caso en el municipio de Andes, Antioquia, 1976-2015
Authors: Zuluaga Salazar Sandra Milena , Otálvaro Castro Gabriel Jaime
Published: June 2020

En 1956 se formaron las primeras promotoras de salud en Colombia, para mejorar la salud de las poblaciones de los territorios más marginados. Las promotoras, especialmente mujeres, se convirtieron en protagonistas de la vida comunitaria rural, al jugar un papel que trascendió el quehacer sanitario. El estudio se propuso comprender críticamente el rol social y sanitario de las promotoras de salud en el municipio de Andes, Antioquia, en el periodo 1976-2015. Se realizó un estudio de caso a través de entrevistas y revisión documental; participaron promotoras de amplia trayectoria en ejercicio laboral, funcionarios y líderes comunitarios. La institucionalización de las promotoras irrumpió como la principal alternativa de salud para las comunidades rurales del país. Las transformaciones del sistema de salud han producido el constreñimiento de esta práctica social, aun cuando continúan vigentes. Las promotoras han jugado un papel que trasciende la atención sanitaria, desempeñan un importante rol en la construcción de tejido social y la gestión del cambio sociocultural en la ruralidad colombiana.
Frictional Detachment Between Slender Whisker and Round Obstacle
Authors: Wang T. J. , Nie J. F. , Peng Q. , Liu X. , Wei Y. G.
Published: June 2020

In nature, hair-like whiskers are used to detect surrounding information, such as surface texture and air flow field. The detection requires a comprehensive understanding of the relationship between whisker deformation and the contact force. With a whisker being modeled as a slender beam, the contact problem cannot be solved by small deformation beam theory and thus requires a new mechanical model to build up the relationship between whisker deformation and the contact force. In this work, the contact problem between a whisker and a round obstacle is solved, considering three factors: large deformation of the whisker, size of the obstacle, and frictional effect of the interface. Force and energy histories during the contact are analyzed under two motion modes: translation and rotation. Results show that the rotational mode is preferred in nature, because rotation of a whisker over an obstacle requires less energy for frictional dissipation. In addition, there are two types of detachment during the slip between the whisker and the obstacle. The detachment types are dependent on the whisker’s length and can be explained by the buckling theory of a slender beam.
The Effect of Step Misalignment on Purge Flow Cooling of Nozzle Guide Vane at Transonic Conditions
Authors: Luehr Luke , Sibold Ridge , Mao Shuo , Ng Wing F. , Li Zhigang , Xu Hongzhou , Fox Michael
Published: June 2020

This study describes a detailed investigation on the effects that upstream step misalignment and upstream purge film cooling have on the endwall heat transfer for first stage nozzle guide vanes (NGVs) in a gas turbine at transonic conditions. Endwall Nusselt number and adiabatic film-cooling effectiveness distributions were experimentally measured and compared with flow visualization. Tests were conducted in a transonic linear cascade blowdown facility at an inlet freestream turbulence intensity of 16%, an exit Mach number of 0.85, and an exit Re = 1.5 × 106 based on axial chord. Varied upstream purge blowing ratios (BRs) and a no-blowing case were tested for three different upstream step geometries, the baseline (no misalignment), a span-wise upstream step of +4.86% span, and a step of −4.86% span. Experimentation shows that compared with no-blowing case, the addition of upstream purge film cooling increases the Nusselt number at injection upward of 50% but lowers it in the passage throat by approximately 20%. The backward facing step induces more turbulent mixing between the coolant and mainstream flows, thus reducing film effectiveness coverage and increasing Nusselt number by nearly 40% in the passage throat. In contrast, the presence of a forward step creates a more stable boundary layer for the coolant flow aiding to help keep the film attached to the endwall. Increasing the blowing ratio increases film-cooling effectiveness and endwall coverage up to a certain point, beyond which, the high momentum of the coolant results in poor cooling performance due to jet liftoff.
Critical Points for Variable Length Elastica With a Fixed Point Constraint Under Displacement Control
Authors: Wang Qiang , Zou Hai-Lin , Deng Zi-Chen
Published: June 2020

This paper studies a variable length elastica with a fixed point constraint by an assembly method that regards the whole elastica as an assembly of two components, i.e., pinned-clamped elasticas. The pinned-clamped elastica is obtained based on the post-buckled deformed shape with one internal inflection point. Thus, multiple coexisting solutions can be located accurately, which reveals three distinct equilibrium paths for the complete load–displacement curves. Under displacement control, two critical points on two equilibrium paths are found at saddle-node bifurcations. Interestingly, a new critical point is located at the boundary point of one equilibrium path, where the shapes of two pinned-clamped elasticas are two different post-buckled deformed shapes. Changing the location of the fixed point constraint allows the position of the boundary point to be easily manipulated, and the associated snap-through phenomenon can occur on different equilibrium paths. This flexible generation of the snap-through phenomenon is useful for designing engineering systems that require controllable snap-through.
Influence of Two External Excitations for Brake Stick-Slip Behavior Using New Numerical Calculation Method
Authors: Liu Fuhao , Li Hongguang , Jiang Hanjun , Jiang Suyu
Published: June 2020

In this paper, a dynamic brake model has been constructed by incorporating the brake rotor's speed and the brake normal force as excitation sources. By introducing two permissible errors (ε1,2), a novel computation algorithm is proposed to reduce the ill-conditioning, arising from the nonlinear friction. Its validation illustrates that the proposed method, using double-changed time-steps and smarter adaptive time-step reduced method, is more reliable than other integral equation solvers with a higher accuracy as well as less computation time. Moreover, the influences of external excitations on the dynamic characteristic of the brake system are also analyzed, and an estimation for the occurrence of unstable vibration is investigated. The results demonstrate the different contributions of the two external excitations on the dynamic characteristic. The brake system has more unstable vibration at a higher brake normal force and a lower brake rotor's speed with small fluctuation. Furthermore, the higher brake rotor's speed could generate more positive damping effect, which could reduce and suppress the occurrence of the sick-slip vibrations. In practice, these instabilities can be minimized by appropriate selection of the two external, which can be adjusted according to the advanced working requirements.
Molecular Dynamics Simulation of Ultra-Fast Phase Transition in Water Nanofilms
Authors: Porterfield Malcolm , Borca-Tasciuc Diana-Andra
Published: June 2020

Molecular dynamics simulations are used to explore explosive boiling of thin water films on a gold substrate. In particular, water films of 0.7, 1.6, and 2.5 nanometer thickness were examined. Three different surface wettabilities with contact angles of 11 deg, 47 deg, and 110 deg were simulated along with substrate temperatures of 400 K, 600 K, 800 K, and 1000 K. The 11 and 47 deg contact angles were obtained using a Morse interaction potential between the water film and gold substrate while the 47 and 110 deg contact angles were obtained via a Lennard-Jones potential. Evaporation was the first mode of phase change observed in all cases and explosive boiling did not occur until the substrate reached a temperature of 800 K. When explosive boiling was present for all three contact angles, it was consistently shown to occur first for the surface with a 47 deg contact angle and Lennard-Jones potential. These results suggest that explosive boiling onset is strongly dependent on the particularities of the interaction potential. For instance, the Morse potential is smoother when compared to the Lennard-Jones potential, but has more interaction sites per molecule—two hydrogen atoms and one oxygen atom versus one oxygen atom. Thus, even when the water film reaches a higher temperature with the Morse potential, explosive boiling onset is delayed as more interaction sites have to be disrupted. These results suggest that contact angle alone is insufficient and both the interaction strength and the number of atoms interacting at the interface must be considered when investigating trends of explosive boiling with surface wettability.
Geometrical Optimization of a Smooth Solar Air Heater Duct
Authors: Chhaparwal G. K. , Dayal Ram , Goyal Rahul , Srivastava Ankur
Published: June 2020

This study presents the geometrical optimization of a solar air heater. A reasonable working range of geometrical parameters: length 1–3 m, width 0.1–0.5 m, and height 0.005–0.05 m (or aspect ratio 1–20), is investigated as per general applications and installation constraints. The effect of these geometrical parameters on thermal (heat flux and outlet air temperature) and hydraulic (air velocity, mass flowrate, pressure loss and pumping power, and Bejan number) parameters are theoretically studied. Later, a numerical investigation is carried out with an optimum geometry of SAH-duct (length 2.44 mm and width 0.3 m), for aspect ratio 4–18 and Re 3000–15,000. An experimental study is also done to validate numerical results. The heat transfer and frictional loss do not show a significant change in the values for the aspect ratio 8–12.
Individual arc-discharge synthesized multiwalled carbon nanotubes probed with multiple measurement techniques
Authors: Ahlskog Markus , Hokkanen Matti J. , Levshov Dmitry , Svensson Krister , Volodin Alexander , van Haesendonck Chris
Published: June 2020

Arc-discharge synthesized multiwalled carbon nanotubes (AD-MWNT), or related MWNTs, exhibit a good quality compared to the more common type of MWNT synthesized by catalytic chemical vapor deposition methods. Yet experimental measurements on these are rather few and typically have not correlated data from different measurement techniques. Here, the authors report Raman spectroscopy, scanning probe microscopy, conductivity measurements, and force microscopy on single AD-MWNTs. The results demonstrate the high quality of AD-MWNTs and are compatible with the view of them as the best approximation of MWNTs as an assembly of defect-free concentric individual single-walled carbon nanotubes. The authors also demonstrate conductance measurements over a step on the surface of an AD-MWNT, which is due to an abruptly broken outer layer(s), whereby the interlayer resistance is measured.
Increased lysosomal biomass is responsible for the resistance of triple-negative breast cancers to CDK4/6 inhibition
Authors: Fassl Anne , Brain Christopher , Abu-Remaileh Monther , Stukan Iga , Butter Deborah , Stepien Piotr , Feit Avery S. , Bergholz Johann , Michowski Wojciech , Otto Tobias , Sheng Qing , Loo Alice , Michael Walter , Tiedt Ralph , DeAngelis Carmine , Schiff Rachel , Jiang Baishan , Jovanovic Bojana , Nowak Karolina , Ericsson Maria , Cameron Michael , Gray Nathanael , Dillon Deborah , Zhao Jean J. , Sabatini David M. , Jeselsohn Rinath , Brown Myles , Polyak Kornelia , Sicinski Piotr
Published: June 2020

This study presents strategies to render triple-negative breast cancers sensitive to CDK4/6 inhibitors.
Genomic Profiling of Evolving Daptomycin Resistance in a Patient with Recurrent Staphylococcus argenteus Sepsis
Authors: Hao Samantha , Abdelghany Mazin , Lyden Amy , Sit Rene , Tan Michelle , Tato Cristina M. , DeRisi Joseph L. , Miller Steve , Doernberg Sarah B. , Langelier Charles
Published: June 2020

Staphylococcus argenteus
is a novel staphylococcal species associated with invasive disease. We report the first case of daptomycin/vancomycin-resistant
S. argenteus
, initially speciated as
Staphylococcus aureus
, that developed from repeated treatment with daptomycin for a complex vascular graft infection. Whole-genome sequencing of longitudinally collected isolates identified acquisition of MprF S337L, a mutation predicted to increase surface charge and repel cationic molecules.
Engineering a Carotenoid-Overproducing Strain of Azospirillum brasilense for Heterologous Production of Geraniol and Amorphadiene
Authors: Mishra Shivangi , Pandey Parul , Dubey Ashutosh Prakash , Zehra Aafreen , Chanotiya Chandan Singh , Tripathi Anil Kumar , Mishra Mukti Nath
Published: June 2020

To date, the major host organisms used for the heterologous production of terpenoids, i.e.,
E. coli
and
S. cerevisiae
, do not have high-flux isoprenoid pathways and involve tedious metabolic engineering to increase the precursor pool. Since carotenoid-producing bacteria carry endogenous high-flux isoprenoid pathways, we used a carotenoid-producing mutant of
A. brasilense
as a host to show its suitability for the heterologous production of geraniol and amorphadiene as a proof-of-concept. The advantages of using
A. brasilense
as a model system include (i) dispensability of carotenoids and (ii) the possibility of overproducing carotenoids through a single mutation to exploit high carbon flux for terpenoid production.
Protein A-Mediated Binding ofStaphylococcusspp. to Antibodies in Flow Cytometric Assays and Reduction of This Binding by Using Fc Receptor Blocking Reagent
Authors: Cronin Ultan P. , Girardeaux Laura , O’Meara Elaine , Wilkinson Martin G.
Published: June 2020

This study characterizes a widespread but little-studied problem associated with the antibody-based detection of microbes—theStaphylococcusprotein A (SpA)-mediated binding of IgG antibodies—and offers a solution: the use of commercial FcR blocking reagent. A common source of false-positive signals in the detection of microbes in clinical, food, or environmental samples can be eliminated by applying this study’s findings. Using flow cytometry, the authors demonstrate the extent of heterogeneity in a culture’s SpA-mediated binding of antibodies and that the degree of SpA-mediated antibody binding is strain, growth phase, and food matrix dependent and influenced by simulated food processing treatments and cell adherence. In addition, our studies of SpA-mediated binding ofStaphylococcusspp. to antibodies against other bacterial species produced a very nuanced picture, leading us to recommend testing against multiple strains ofS. aureusandS. hyicusof all antibodies to be incorporated into any immunoassay designed to detect a non-Staphylococcusspp.
Prevalence of Mycoplasma genitalium and Antibiotic Resistance-Associated Mutations in Patients at a Sexually Transmitted Infection Clinic in Iceland, and Comparison of the S-DiaMGTV and Aptima Mycoplasma genitalium Assays for Diagnosis
Authors: Hilmarsdóttir Ingibjörg , Arnardóttir Eva Mjöll , Jóhannesdóttir Elísabet Reykdal , Valsdóttir Freyja , Golparian Daniel , Hadad Ronza , Vigfússon Hannes Bjarki , Unemo Magnus
Published: June 2020

Mycoplasma genitalium
is prevalent among attendees in sexually transmitted infection (STI) clinics, and therapy is hampered by rapidly rising levels of resistance to azithromycin and moxifloxacin. In this study, we evaluated, for the first time in Iceland, the prevalence of
M. genitalium
and azithromycin and moxifloxacin resistance-associated mutations and assessed the diagnostic performance of the CE/
in vitro
diagnosis (IVD)-marked S-DiaMGTV (Diagenode Diagnostics) versus the U.
Axl Deficiency Promotes the Neuroinvasion of Japanese Encephalitis Virus by Enhancing IL-1α Production from Pyroptotic Macrophages
Authors: Wang Zhao-Yang , Zhen Zi-Da , Fan Dong-Ying , Qin Cheng-Feng , Han Dai-Shu , Zhou Hong-Ning , Wang Pei-Gang , An Jing
Published: June 2020

Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that causes Japanese encephalitis (JE), the most commonly diagnosed viral encephalitis worldwide. The fatality rate of JE is 20%, and nearly half of the surviving patients develop neuropsychiatric sequelae. Axl is a receptor tyrosine kinase that plays multiple roles in flaviviral infections. Currently, the involvement of Axl in JEV infection remains enigmatic. In this study, we demonstrate that Axl impedes the pathogenesis of severe JE in mice by maintaining blood-brain-barrier (BBB) integrity and restricting viral neuroinvasion. Furthermore, serum IL-1α is a key mediator of this process and is primarily released by JEV-infected pyroptotic macrophages to elicit BBB breakdown, while an IL-1α antagonist can effectively reduce the incidence of severe JE. Our work uncovers the protective role of Axl in antagonizing severe JE and shows that the use of an IL-1α antagonist may be a promising tactic to prevent severe JE.
Isolation and Characterization of the First Freshwater Cyanophage InfectingPseudanabaena
Authors: Zhang Dong , You Fang , He Yiliang , Te Shu Harn , Gin Karina Yew-Hoong
Published: June 2020

This study presents the isolation of the very first freshwater cyanophage, PA-SR01, that infectsPseudanabaena, and fills an important knowledge gap on freshwater cyanophages as well as cyanophages infectingPseudanabaena.
Expression of Separate Heterologous Proteins from the Rotavirus NSP3 Genome Segment Using a Translational 2A Stop-Restart Element
Authors: Philip Asha A. , Patton John T.
Published: June 2020

Rotaviruses are a major cause of severe gastroenteritis in infants and young children. Recently, a highly efficient reverse genetics system was developed that allows genetic manipulation of the rotavirus segmented double-stranded RNA genome. Using the reverse genetics system, we show that it is possible to modify one of the rotavirus genome segments (segment 7) such that virus gains the capacity to express a separate heterologous protein in addition to the full complement of viral proteins. Through this approach, we have generated wild-type-like rotaviruses that express various fluorescent reporter proteins, including UnaG (green), mRuby (far red), mKate (red), and TagBFP (blue). Such strains will be of value in probing rotavirus biology and pathogenesis by live cell imagining techniques. Notably, our work indicates that the rotavirus genome is remarkably flexible and able to accommodate significant amounts of heterologous RNA sequence, raising the possibility of using the virus as a vaccine expression vector.
COVID-19 Vaccines: “Warp Speed” Needs Mind Melds, Not Warped Minds
Authors: Moore John P. , Klasse P. J.
Published: June 2020

In this review, we address issues that relate to the rapid “Warp Speed” development of vaccines to counter the COVID-19 pandemic. We review the antibody response that is triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection of humans and how it may inform vaccine research. The isolation and properties of neutralizing monoclonal antibodies from COVID-19 patients provide additional information on what vaccines should try to elicit. The nature and longevity of the antibody response to coronaviruses are relevant to the potency and duration of vaccine-induced immunity.
Recognition Patterns of the C1/C2 Epitopes Involved in Fc-Mediated Response in HIV-1 Natural Infection and the RV114 Vaccine Trial
Authors: Tolbert William D. , Van Verna , Sherburn Rebekah , Tuyishime Marina , Yan Fang , Nguyen Dung N. , Stanfield-Oakley Sherry , Easterhoff David , Bonsignori Mattia , Haynes Barton F. , Moody M. Anthony , Ray Krishanu , Ferrari Guido , Lewis George K. , Pazgier Marzena
Published: June 2020

Antibody-dependent cellular cytotoxicity (ADCC) correlated with a reduced risk of infection from HIV-1 in the RV144 vaccine trial, the only HIV-1 vaccine trial to date to show any efficacy. Antibodies specific for CD4-induced envelope (Env) epitopes within constant region 1 and 2 (cluster A region) were induced in the RV144 trial and their ADCC activities were implicated in the vaccine efficacy. We present structural analyses of the antigen epitope targets of several RV144 antibodies specific for this region and C11, an antibody induced in natural infection, to show what the differences are in epitope specificities, mechanism of antigen recognition, and ADCC activities of antibodies induced by vaccination and during the course of HIV infection. Our data suggest that the truncated AIDSVAX gp120 variants used in the boost of the RV144 regimen may have shaped the vaccine response to this region, which could also have contributed to vaccine efficacy.
Divergent Evolution of PcF/SCR74 Effectors in Oomycetes Is Associated with Distinct Recognition Patterns in Solanaceous Plants
Authors: Lin Xiao , Wang Shumei , de Rond Laura , Bertolin Nicoletta , Wouters Roland H. M. , Wouters Doret , Domazakis Emmanouil , Bitew Mulusew Kassa , Win Joe , Dong Suomeng , Visser Richard G. F. , Birch Paul , Kamoun Sophien , Vleeshouwers Vivianne G. A. A.
Published: June 2020

Immune receptors at the plant cell surface can recognize invading microbes. The perceived microbial molecules are typically widely conserved and therefore the matching surface receptors can detect a broad spectrum of pathogens. Here we describe a family of
Phytophthora
small extracellular proteins that consists of conserved subfamilies that are widely recognized by solanaceous plants. Remarkably, one subclass of SCR74 proteins is highly diverse, restricted to the late blight pathogen
Phytophthora infestans
and is specifically detected in wild potato plants. The diversification of this subfamily exhibits signatures of a coevolutionary arms race with surface receptors in potato. Insights into the molecular interaction between these potato-specific receptors and the recognized
Phytophthora
proteins are expected to contribute to disease resistance breeding in potato.
Lateral Gene Transfer Drives Metabolic Flexibility in the Anaerobic Methane-Oxidizing Archaeal Family
Methanoperedenaceae
Authors: Leu Andy O. , McIlroy Simon J. , Ye Jun , Parks Donovan H. , Orphan Victoria J. , Tyson Gene W.
Published: June 2020

AOM by microorganisms limits the atmospheric release of the potent greenhouse gas methane and has consequent importance for the global carbon cycle and climate change modeling. While the oxidation of methane coupled to sulfate by consortia of anaerobic methanotrophic (ANME) archaea and bacteria is well documented, several other potential electron acceptors have also been reported to support AOM. In this study, we identify a number of novel respiratory strategies that appear to have been laterally acquired by members of the
Methanoperedenaceae
, as they are absent from related archaea and other ANME lineages. Expanding the known metabolic potential for members of the
Methanoperedenaceae
provides important insight into their ecology and suggests their role in linking methane oxidation to several global biogeochemical cycles.
Soil Carbon, Nitrogen, and Phosphorus Cycling Microbial Populations and Their Resistance to Global Change Depend on Soil C:N:P Stoichiometry
Authors: Luo Gongwen , Xue Chao , Jiang Qianhong , Xiao Yan , Zhang Fengge , Guo Shiwei , Shen Qirong , Ling Ning
Published: June 2020

To be effective in predicting future stability of soil functions in the context of various external disturbances, it is necessary to follow the effects of global change on functionally specialized microbes related to C and nutrient cycling. Our study represents an exploratory effort to couple the stoichiometric drivers to microbial populations related with main C, N, and P cycling and their resistances to global change. The abundance of microbial groups involved in cellulose, starch, and xylan degradation, nitrification, N fixation, denitrification, organic P mineralization, and inorganic P dissolution showed a high stoichiometry dependency. Resistance of these microbial populations to global change could be predicted by soil C:N:P stoichiometry. Our work highlights that stoichiometric balance in soil C and nutrients is instrumental in maintaining the stability and adaptability of ecosystem functions under global change.
Secondary Metabolism in the Gill Microbiota of Shipworms (Teredinidae) as Revealed by Comparison of Metagenomes and Nearly Complete Symbiont Genomes
Authors: Altamia Marvin A. , Lin Zhenjian , Trindade-Silva Amaro E. , Uy Iris Diana , Shipway J. Reuben , Wilke Diego Veras , Concepcion Gisela P. , Distel Daniel L. , Schmidt Eric W. , Haygood Margo G.
Published: June 2020

We define a system in which the major symbionts that are important to host biology and to the production of secondary metabolites can be cultivated. We show that symbiotic bacteria that are critical to host nutrition and lifestyle also have an immense capacity to produce a multitude of diverse and likely novel bioactive secondary metabolites that could lead to the discovery of drugs and that these pathways are found within shipworm gills. We propose that, by shaping associated microbial communities within the host, the compounds support the ability of shipworms to degrade wood in marine environments. Because these symbionts can be cultivated and genetically manipulated, they provide a powerful model for understanding how secondary metabolism impacts microbial symbiosis.
Bone marrow involvement with Merkel cell carcinoma
Authors: Khan Ahmad , Adil Shahroz , Estalilla Oscar C , Jubelirer Steven
Published: June 2020

Merkel cell carcinoma (MCC) is a rare but highly aggressive cutaneous tumour. Most tumours occur in the head and neck, extremities or torso and 36% of them involve the face. Bone marrow involvement in MCC is rare and to our knowledge only nine cases reported in the English literature. Bone marrow biopsy is not usually performed to stage MCC; thus, the true incidence of bone marrow involvement may be under-reported. The majority of the cases reported in the literature have some form of immunosuppression, which suggests a strong association. We report a case of extensive bone marrow involvement from MCC in an 80-year-old Caucasian woman with a history of rheumatoid arthritis treated with adalimumab, methotrexate and prednisone. It may be prudent to include bone marrow biopsy in the staging of MCC in immune-compromised patients.
Rare case of pseudohypoaldosteronism in a neonate secondary to congenital hydrometrocolpos
Authors: Kumar Shruti , McDermott Helen , Kamupira Sheilah , Agwu Juliana Chizo
Published: June 2020

Pseudohypoaldosteronism (PHA) due to obstructive uropathy, urinary tract infections and congenital urogenital malformations has been reported in the literature; however, there are no reports of PHA associated with hydrometrocolpos due to a common urogenital tract. Hydrometrocolpos is a condition resulting in distension of the vagina and uterus due to accumulation of secretions (other than blood), caused by increased oestrogenic stimulation and vaginal outflow obstruction. We report on a neonatal case of PHA caused by recurrent hydrometrocolpos presenting with vomiting and poor weight gain. There was significant hyponatraemia, hyperkalaemia, and anaemia requiring medical stabilisation prior to surgery. The mechanism by which PHA occurs in obstruction involves renal tubular dysfunction due to pressure from hydronephrosis and the release of intrarenal cytokines. In addition, there is an immature or resistant renal tubular responsiveness to aldosterone during infancy. Clinicians should be aware of this uncommon but serious presentation.
Pheochromocytoma and gastrointestinal stromal tumours in an adult neurofibromatosis type 1 patient: a rare co-occurrence
Authors: Vongsumran Nuttawut , Kongkarnka Sarawut , Watanawittawas Pittaporn , Manosroi Worapaka
Published: June 2020

The risk of tumours including pheochromocytoma and gastrointestinal stromal tumour (GIST) has been reported to be higher in neurofibromatosis type 1 (NF1) patients. The concomitant occurrence of these two tumours was rare in NF1 patient and most were symptomatic. In this case report, we describe the case of a 47-year-old man with NF1 who presented with microscopic haematuria. Neither hypertension nor any gastrointestinal symptoms were reported by the patient. While investigating for haematuria, left adrenal mass and arterial enhancing lesions in the small bowel were incidentally documented during computerised urography. The patient subsequently underwent a left adrenalectomy and small bowel resection. The pheochromocytoma and multiple GIST tumours were diagnosed based on pathology. Here, we discuss the rare association of pheochromocytoma and GIST and the asymptomatic presentation of those tumours in an NF1 patient. We further suggest that in NF1 patients a heightened level of vigilance can help identify this infrequent combination.
Multimodality therapy of endometrial glassy cell carcinoma: a rare type of cancer
Authors: Kazakova Vera , Moreno Vanegas Yenny Alejandra , Kadamkulam Syriac Arun , Kozyreva Olga
Published: June 2020

Glassy cell carcinoma (GCC) is a rare histologically aggressive cancer subtype of the cervix that is associated with poor prognosis. Only 16 cases of endometrial GCC (EGCC) have been described in the literature to date. The data on prognostic factors and management of EGCC are limited and no optimal treatment protocol has been established. We describe a case of a 67-year-old woman who presented with postmenopausal bleeding and was diagnosed with stage IA EGCC. The patient’s risk factors included histology, age and lower uterine segment involvement. The patient was successfully treated with total hysterectomy and bilateral salpingo-oophorectomy with pelvic node dissection followed by adjuvant sandwich chemotherapy and radiotherapy. The patient has no evidence of disease recurrence for 18 months. This is the first case of EGCC management with adjuvant multimodality therapy.
Poorly controlled diabetes mellitus alters placental structure, efficiency, and plasticity
Authors: Nteeba Jackson , Varberg Kaela M , Scott Regan L , Simon Mikaela E , Iqbal Khursheed , Soares Michael J
Published: June 2020

Introduction

The hemochorial placenta provides a critical barrier at the maternal–fetal interface to modulate maternal immune tolerance and enable gas and nutrient exchange between mother and conceptus. Pregnancy outcomes are adversely affected by diabetes mellitus; however, the effects of poorly controlled diabetes on placental formation, and subsequently fetal development, are not fully understood.

Research design and methods

Streptozotocin was used to induce hyperglycemia in pregnant rats for the purpose of investigating the impact of poorly controlled diabetes on placental formation and fetal development. The experimental paradigm of hypoxia exposure in the pregnant rat was also used to assess properties of placental plasticity. Euglycemic and hyperglycemic rats were exposed to ambient conditions (~21% oxygen) or hypoxia (10.5% oxygen) beginning on gestation day (gd) 6.5 and sacrificed on gd 13.5. To determine whether the interaction of hyperglycemia and hypoxia was directly altering trophoblast lineage development, rat trophoblast stem (TS) cells were cultured in high glucose (25 mM) and/or exposed to low oxygen (0.5% to 1.5%).

Results

Diabetes caused placentomegaly and placental malformation, decreasing placental efficiency and fetal size. Elevated glucose disrupted rat TS cell differentiation in vitro. Evidence of altered trophoblast differentiation was also observed in vivo, as hyperglycemia affected the junctional zone transcriptome and interfered with intrauterine trophoblast invasion and uterine spiral artery remodeling. When exposed to hypoxia, hyperglycemic rats showed decreased proliferation and ectoplacental cone development on gd 9.5 and complete pregnancy loss by gd 13.5. Furthermore, elevated glucose concentrations inhibited TS cell responses to hypoxia in vitro.

Conclusions

Overall, these results indicate that alterations in placental development, efficiency, and plasticity could contribute to the suboptimal fetal outcomes in offspring from pregnancies complicated by poorly controlled diabetes.