bluuebunny/crossref_metadata_2025 huggingface dataset:
Short-term transcriptomic responses of Populus euphratica roots and leaves to drought stress
Authors: Jiao Peipei , Wu Zhihua , Wang Xu , Jiang Zhenbo , Wang Yanqin , Liu Hong , Qin Rui , Li Zhijun
Published: April 2020

Populus euphratica Oliv., the Euphrates poplar, is the tallest tree species in the arid desert areas of Northwest China. Investigation of its drought-resistance genes is valuable to increase understanding of drought resistance mechanisms. RNA-seq of leaves and roots under drought simulation by 25% polyethylene glycol-6000 (PEG 6000) were performed at 0, 4, and 12 h. Leaves and roots responded differently to drought via differentially upregulated and downregulated genes; more genes were downregulated than upregulated in both leaves and roots. Additionally, these differentially expressed genes were enriched in different GO terms and KEGG pathways. For example, GO term ‘response to organic substance’ and KEGG pathway ‘nitrogen metabolism’ were enriched for drought-stressed leaves, while GO term ‘cell wall organization or biogenesis’ and KEGG pathway ‘zeatin biosynthesis’ were enriched for drought-stressed roots. The enrichment of the GO term ‘enzyme linked receptor protein signalling pathway’ in both leaf and root drought responses suggests that these tissues may also have similar mechanisms. However, roots under drought stress for four hs responded by activating programed cell death. The KEGG pathway ‘plant hormone signal transduction’ was detected for 4- and 12-h drought-stressed leaves and 12-h drought-stressed roots, suggesting that plant hormone signal transduction plays an important role in both roots and leaves. GO enrichment of upregulated and downregulated genes for leaves and roots reflect differentially regulatory mechanisms of response to drought stress via different biological processes such as the regulation of photosynthesis and auxin signalling pathway in leaves, and the regulation of defence response and water homeostasis in roots. Fifteen candidate genes, including transcription factors, protein kinase, transporter, late embryogenesis abundant protein and mannitol dehydrogenase, were further selected to determine their response to drought using qRT-PCR. The results show that the expression patterns of 13 of the 15 genes correspond to the RNA-seq results. This study provides new insights into the drought response mechanism of P. euphratica and suggests new candidate gene resources.
Therapy management in bone sarcoma
Authors: Thaler Martin , Khosravi Ismail
Published: April 2020

Bone sarcomas are rare, representing only 0.2% of all diagnosed cancers. Incidence is higher in children and adolescents, but bone sarcomas are still numerically outnumbered by benign bone tumors in this patient cohort. This article summarizes the management of treatment for bone sarcomas. Systemic therapy, surgical therapy, and radiotherapy are presented. Osteosarcoma, chondrosarcoma, and Ewing sarcoma are among the most frequently occurring bone sarcomas in all age groups. In recent decades, multimodal treatment of these rare entities has increased disease-free survival for these patients. As malignant primary bone tumors are rare cancers, and since management is complex, the standard of treatment should be performed by reference centers. If possible, wide en-bloc resection of the bone sarcoma should be performed. The role of radiotherapy in osteosarcoma and chondrosarcoma is limited, but Ewing sarcoma is a radiation-responsive tumor. In primary bone sarcomas, the efficacy of chemotherapy varies according to histological type. Prognosis is poor in patients with osteosarcoma or Ewing’s sarcoma if surgery without neoaqdjuvant chemotherapy is performed. Despite advances in surgical, medical, and radiation therapy, few significant positive changes in overall survival have been observed in patients with these diseases in recent decades.
Minimum momentum flux ratio required to prevent air curtain breakthrough in case of cross-curtain pressure gradients: CFD versus analytical equation
Authors: Khayrullina Adelya , van Hooff Twan , Alanis Ruiz Claudio , Blocken Bert , van Heijst GertJan
Published: April 2020

This paper presents a numerical study on the required momentum flux ratio to prevent air curtain breakthrough in case of cross-curtain (i.e. cross-jet) pressure gradients. 2D steady Reynolds-averaged Navier-Stokes (RANS) CFD simulations with the RNG k-ε turbulence model are employed for jet Reynolds numbers ranging from 5,000 to 30,000. First, the computational model is validated based on particle image velocimetry (PIV) measurements. Second, the influence of several jet parameters on the separation efficiency is evaluated for a moderate cross-jet pressure difference of 10 Pa. These are the ratio of the jet discharge momentum flux to the jet cross-flow momentum flux (momentum flux ratio), the jet height-to-width ratio and the jet discharge angle. Finally, the minimum deflection modulus to prevent jet breakthrough and the corresponding momentum flux ratio by an analytical equation and by CFD are compared. The results show that, for the configuration under study: (1) jets with the smallest height-to-width ratios (β = 18) provide the highest separation efficiency; (2) inclined jets with discharge angles α0 = 5° and 10° provide slightly higher separation efficiency than straight jets (α0 = 0°) and jets with α0 = 20°; (3) the maximum modified separation efficiency is reached at lower momentum flux ratios for jets with smaller height-to-width ratios and for inclined jets; (4) the analytical and CFD values of the optimal momentum flux ratio differ with up to 31.2%. This study shows how the separation efficiency of air curtains can be improved by adjusting certain jet parameters.
A Mindfulness Program to Improve Resident Physicians’ Personal and Work-Related Well-being: a Feasibility Study
Authors: Fendel Johannes C. , Aeschbach Vanessa M. , Göritz Anja S. , Schmidt Stefan
Published: April 2020

Objectives

Many resident physicians suffer from mental distress. This endangers the individual physician as well as the quality of patient care. This study tested the feasibility of a novel 8-week mindfulness program tailored to improve resident physicians’ personal and work-related well-being.

Methods

Participants were nine resident physicians from a major hospital in southern Germany. Feasibility was assessed in seven domains (demand, acceptability, implementation, practicality, adaptation, integration, and preliminary effectiveness), using self-reports, attrition, attendance, and daily home practice. Using a pre-post within-subjects design, changes were assessed in hair cortisol as a biomarker of stress as well as in self-reported personal and work-related well-being.

Results

The program is feasible in all domains. Participants positively rated the program regarding satisfaction, helpfulness, usage, and personal and professional benefit. All participants indicated to recommend the program. There was no study attrition, high attendance, and an average daily home practice of 13.5 min. A medium reduction was observed with hair cortisol secretion (d = 0.64). In terms of personal well-being, medium-to-large improvements were observed with perceived stress (d = 0.58), mental health (d = 0.77), self-attributed mindfulness (d = 0.92), and self-compassion (d = 1.21). In terms of work-related well-being, small-to-medium improvements were observed with self-reported job strain (d = 0.58), effort-reward imbalance (d = 0.36), work-related burnout (d = 0.32), thriving at work (d = 0.24), and physician empathy (d = 0.21).

Conclusions

This study provides evidence that a tailored mindfulness program is feasible and may be effective in reducing hair cortisol secretion and improving resident physicians’ personal and work-related well-being. These promising findings warrant further investigation within a randomized controlled trial.
The Use of 3D-Printing Technology in Calculus Education: Concept Formation Processes of the Concept of Derivative with Printed Graphs of Functions
Authors: Dilling Frederik , Witzke Ingo
Published: April 2020

3D-printing technology has become increasingly important in recent years, offering many possibilities for mathematics teaching and learning. From our point of view, the field of calculus seems to be particularly suitable for the use of 3D-printing. Using the example of 3D-printed graphs of functions, the use of this technology in calculus is discussed within the three approaches of Grundvorstellungen, Subjective Domains of Experience and Empirical Theories. An empirical study, based on the qualitative content analysis according to Philipp Mayring, examines the influence of the models on concept formation processes in the context of derivatives. The focus is on the following research question: “What are the characteristics of concept formation processes of the concept of derivative in the context of 3D-printed graphs of functions?”
Thermal Behavior of Pyrophyllite Ore during Calcination for Thermal Activation for Aluminum Extraction by Acid Leaching
Authors: Erdemoğlu Murat , Birinci Mustafa , Uysal Turan
Published: April 2020

In the production of alumina (Al2O3) from clays by acid leaching, thermal activation by calcination is applied widely as a pre-treatment to improve the dissolution of aluminum. Previous studies have focused only on the thermal behavior of high-purity kaolinite and pyrophyllite, individually. However, thermal activation of complex clay ores containing several silicate minerals and their effect on aluminum extraction have not been studied. The purpose of the present study was to characterize the thermal behavior of a clay ore containing mainly pyrophyllite (Al2Si4O10(OH)2), kaolinite (Al2Si2O5(OH)4), muscovite (KAl2(AlSi3O10)(OH)2), quartz (SiO2), and kyanite (Al2SiO5) from the Pütürge clay deposits (Malatya, Turkey) for possible use in alumina (Al2O3) production by acid leaching. The ore and its calcination products obtained at various temperatures were characterized with respect to their mineral paragenesis, crystal structure, surface morphology, and thermal, calorimetric, and aluminum dissolution properties in order to understand the changes that occurred. Aluminum recovery in the leach solution increased in direct proportion to the dehydroxylation degree (Dtg) of the ore as the calcination temperature increased to 900°C. A maximum aluminum extraction of 90.57% was achieved by leaching of the product from calcination at 900°C. Aluminum extraction decreased sharply above that temperature, even though Dtg increased a little. By increasing the calcination temperature; the structures of pyrophyllite, kaolinite, and muscovite were destroyed by dehydroxylation, resulting in the exfoliation of the mineral layers, thus, a mixture of dehydroxylated phases formed. Depending mainly on the temperature range at which each of the dehydroxylated phases is durable, aluminum could be leached to some extent. The sharp decrease in the extraction of aluminum, iron, and potassium at higher temperatures was attributed to compaction of previously exfoliated layers of the minerals through re-crystallization to form mullite-like structures which seemed insensitive to acid attack during the leaching.
Space use of wild boar (Sus Scrofa) in Budapest: are they resident or transient city dwellers?
Authors: Csókás A. , Schally G. , Szabó L. , Csányi S. , Kovács F. , Heltai M.
Published: April 2020

In our study, we examined the movement of two wild boars marked with GPS/GSM transmitters in city of Budapest. We hypothesised that: the wild boars do not leave the urban area (H1); the wild boars prefer places that are less disturbed by people, and which are rich in potential hiding places (H2); and their home ranges would be smaller than that of wild boars living in non-urban environment (H3). Based on our results, we accepted our first hypothesis, as the wild boars had not left the area of Budapest. However, we partly rejected our second hypothesis: the wild boars preferred urban areas that were forested and richly covered with vegetation; however, human presence therefore disturbance was also high in those areas. The home range sizes of both marked wild boar sows were remarkably smaller than those of the wild boars living in natural environment (H3). City habitat modification, e.g. clearing undergrowth vegetation, could result that wild boars cannot find any hiding places. The significant part of food sources will disappear with the elimination of these places. By eliminating the two main factors together could prevent wild boars finding their living conditions within the city.
Review of Interfaces for Industrial Human-Robot Interaction
Authors: Berg Julia , Lu Shuang
Published: April 2020

Purpose of Review

The review presents an overview of research approaches on human-robot interfaces in industrial and service robotics.

Recent Findings

Research approaches address especially speech and gesture recognition in both fields but are more explored in service robotics. However, the importance of interfaces in industrial robots increases.

The development of human-robot interfaces is leading towards intuitive interfaces, especially using speech and gesture recognition and combining them to multimodal interfaces.
Obstructive Sleep Apnea is Associated with Polycythemia in Hypogonadal Men on Testosterone Replacement Therapy
Authors: Lundy Scott D. , Parekh Neel V. , Shoskes Daniel A.
Published: April 2020

Background

Polycythemia (erythrocytosis) is a known side effect of testosterone (T) replacement therapy (TRT) and appears to correlate with maximum T levels. There is also a well-established association between obstructive sleep apnea (OSA) and the development of polycythemia, which confers additional long-term cardiovascular morbidity. Synergy between TRT and OSA in the development of polycythemia remains poorly understood.

Aim

The objective of this study was to retrospectively assess the relationship of OSA and secondary polycythemia in hypogonadal men receiving TRT.

Methods

We performed a retrospective chart review of all men treated by a single provider from 2015 to 2019 for the diagnosis of hypogonadism. Patients who developed a hematocrit of 52% or greater were classified as having polycythemia. OSA was identified via clinical documentation or use of nocturnal continuous positive airway pressure. Demographics, laboratory values, treatment details, and comorbidities were recorded. Data were reported as mean ± SD for parametric variables and median [interquartile range] for non-parametric values.

Outcome

The primary outcome of this study was the association between OSA and polycythemia in hypogonadal men on TRT.

Results

474 men were included in this study. 62/474 (13.1%) men met the criteria for the diagnosis of polycythemia with a median hematocrit of 53.6 [interquartile range 52.6, 55.5]. Univariate analysis demonstrated a strong positive association between polycythemia and the concomitant diagnosis of OSA in hypogonadal men (P = .002). Even after correcting for age, body mass index (BMI), and peak T levels in the multivariate analysis (P = .01), this relationship remained significant with an odds ratio of 2.09 [95% CI 1.17, 3.76]. 37 men on TRT with polycythemia and OSA were included in the final cohort with a mean age of 59.2 ± 11.4 years, mean BMI of 32.4 ± 6.0, and median time from TRT initiation to polycythemia diagnosis of 3 years. All patients diagnosed with OSA were prescribed continuous positive airway pressure with poor compliance noted in 52.8% of men. 37.8% were managed via phlebotomy and 59.5% were managed via dose de-escalation of TRT. In hypogonadal men on TRT with polycythemia, BMI was the only risk factor strongly associated with OSA (P = .013).

Clinical Translation

In hypogonadal men (particularly those with elevated BMI) on TRT who develop secondary polycythemia, a diagnosis of OSA should be strongly considered.

Strengths & Limitations

This is a single provider retrospective study and further studies are needed to assess generalizability.

Conclusions

In this retrospective single-center cohort, the development of polycythemia in hypogonadal men on TRT was associated with an increased prevalence of OSA.
Regional Ways of Seeing: A Big-Data Approach for Measuring Ancient Visualscapes
Authors: Susmann Natalie M.
Published: April 2020

Archaeologists have long acknowledged the significance of mountains in siting Greek cult. Mountains were where the gods preferred to make contact and there people constructed sanctuaries to inspire intervention. Greece is a land full of mountains, but we lack insight on the ancient Greeks’ view—what visible and topographic characteristics made particular mountains ideal places for worship over others, and whether worshiper preferences ever changed. This article describes a data collection and analysis methodology for landscapes where visualscape was a significant factor in situating culturally significant activities. Using a big-data approach, four geospatial analyses are applied to every cultic place in the Peloponnesian regions of the Argolid and Messenia, spanning 2800–146 BC. The fully described methodology combines a number of experiences—looking out, looking toward, and climbing up—and measures how these change through time. The result is an active historic model of Greek religious landscape, describing how individuals moved, saw, and integrated the built and natural world in different ways. Applied elsewhere, and even on nonreligious locales, this is a replicable mode for treating the natural landscape as an artifact of human decision: as a space impacting the siting of meaningful locales through history.
Turbo-electric propulsive fuselage aircraft BLI benefits: A design space exploration using an analytical method
Authors: Giannakakis P. , Pornet C. , Turnbull A.
Published: April 2020

Turbo-electric propulsive fuselage aircraft featuring Boundary-Layer Ingestion (BLI) are considered promising candidates to achieve the emissions reduction targets set for aviation. This paper presents an analytical method capable of estimating the BLI benefit at aircraft level, enabling a quick exploration of the propulsive fuselage design space. The design space exploration showed that the assumptions regarding the underwing turbofans and BLI fan mass estimation can have an important impact on the final fuel burn estimation. The same applies to the total efficiency assumed for the electric transmission, the range of the aircraft mission, and the propulsive efficiency of the engines used as benchmark. The regional jet and short- to medium-range aircraft classes seem to be the most promising as the ingested drag and power saving are among the largest, with long-range aircraft being just behind. The future introduction of advanced technologies, which target the reduction of vortex and wave dissipation at aircraft level, could increase the potential benefit of propulsive fuselage BLI. On the other hand, the potential benefit would be decreased if more efficient and lighter ultra high bypass ratio engines were used as benchmark.
Effectiveness of Public versus Private Ownership: Violations of the Safe Drinking Water Act (SDWA)
Authors: Fu Guanlong , Liu Pengfei , Swallow Stephen K.
Published: April 2020

The relative performance of public and private enterprises has been long debated. We construct a comprehensive violation dataset based on the EPA's Safe Drinking Water Information System to empirically investigate the compliance behavior of publicly and privately owned Public Water Systems (PWSs). Our results show that publicly owned PWSs commit significantly more Maximum Contamination Level, Treatment Technique, and Health-Related violations but fewer Monitor and Reporting violations than privately owned PWSs. We also find that municipal-level heterogeneities explain a substantial amount of variation in violation behaviors among PWSs, suggesting water supply quality depends crucially on location-specific regulations and local economic conditions.
Clinical characteristics associated with COVID-19 severity in California
Authors: Rubin Samuel J. S. , Falkson Samuel R. , Degner Nicholas R. , Blish Catherine
Published: April 2020

Given the rapidly progressing coronavirus disease 2019 (COVID-19) pandemic, this report on a US cohort of 54 COVID-19 patients from Stanford Hospital and data regarding risk factors for severe disease obtained at initial clinical presentation is highly important and immediately clinically relevant. We identified low presenting oxygen saturation as predictive of severe disease outcomes, such as diagnosis of pneumonia, acute respiratory distress syndrome, and admission to the intensive care unit, and also replicated data from China suggesting an association between hypertension and disease severity. Clinicians will benefit by tools to rapidly risk stratify patients at presentation by likelihood of progression to severe disease.
Plagues, pandemics and epidemics in Irish history prior to COVID-19 (coronavirus): what can we learn?
Authors: Kelly B. D.
Published: April 2020

Objectives:

This paper seeks to provide a brief overview of epidemics and pandemics in Irish history and to identify any lessons that might be useful in relation to psychiatry in the context of COVID-19.

Methods:

A review of selected key reports, papers and publications related to epidemics and pandemics in Irish history was conducted.

Results:

Viruses, epidemics and pandemics are recurring features of human history. Early Irish sources record a broad array of plagues, pandemics and epidemics including bubonic plague, typhus, cholera, dysentery and smallpox, as well as an alleged epidemic of insanity in the 19th century (that never truly occurred). Like the Spanish flu pandemic (1918–20), COVID-19 (a new coronavirus) presents both the challenge of the illness itself and the problems caused by the anxiety that the virus triggers. Managing this anxiety has always been a challenge, especially with the Spanish flu. People with mental illness had particularly poor outcomes with the Spanish flu, often related to the large, unhygienic mental hospitals in which so many were housed.

Conclusions:

Even today, a full century after the Spanish flu pandemic, people with mental illness remain at increased risk of poor physical health, so it is imperative that multi-disciplinary care continues during the current outbreak of COVID-19, despite the manifest difficulties involved. The histories of previous epidemics and pandemics clearly demonstrate that good communication and solidarity matter, now more than ever, especially for people with mental illness.
SAFE ZONES AND THE INTERNAL PROTECTION ALTERNATIVE
Authors: Ní Ghráinne Bríd
Published: April 2020

A ‘safe zone’ refers to an area established in armed conflict for the purposes of protecting civilians. This article provides the first legal analysis of whether safe zones can be invoked as a ground for refusing asylum. It examines the concept of the Internal Protection Alternative (IPA) which posits that an individual is not a refugee if there is a safe place within his/her country where he/she can relocate. It clarifies the applicable criteria in the IPA inquiry and uses three case studies to illustrate that safe zones can only qualify as lawful IPAs in exceptional circumstances.
PASSPORTS, THE RIGHT TO TRAVEL, AND NATIONAL SECURITY IN THE COMMONWEALTH
Authors: Scott Paul F.
Published: April 2020

This article, on the basis of a consideration of the development of the law relating to the use of passports as a tool of national security in the United Kingdom, Canada, Australia and New Zealand, challenges the common law conception of passports, arguing that passports effectively confer rights and so, consequentially, that the refusal or withdrawal of a passport represents a denial of rights. From this conclusion a number of points flow. Though these consequences are most acute for the United Kingdom and Canada, in which passports remain regulated by, and are issued under, prerogative powers, there are also a number of points of significance for Australia and New Zealand, where passports have a statutory basis.
Impacts of adding functional oils or sodium monensin in high-concentrate diets on performance, feeding behaviour and rumen morphometrics of finishing Nellore cattle
Authors: Melo A. C. B. , Pereira M. C. S. , Rigueiro A. L. N. , Estevam D. D. , Toledo A. F. , Assumpção A. H. P. M. , Dellaqua J. V. T. , Lelis A. L. J. , Millen D. D.
Published: April 2020

This study, conducted at the São Paulo State University feedlot, Dracena campus, Brazil, was designed as a completely randomized block with 2 × 2 factorial arrangement of treatments to evaluate the effects of adding functional oils (FO) or sodium monensin (MON) on feedlot performance, carcass traits, feeding behaviour and rumen morphometrics of Nellore cattle. Ninety-six 20-mo-old Nellore bulls (365.52 ± 39.19 kg) were randomly allocated to 24 pens (n = 4/pen), which were assigned to the treatments: (1) Control (no feed additives); (2) FO (500 ppm); (3) MON (27 ppm); and (4) MON + FO (27 + 500 ppm, respectively). Each treatment was replicated 6 times, and cattle were fed for 105 days. From 0 to 28 days on feed, cattle fed FO had lower dry matter intake (DMI) variation, sorted for medium particles and presented smaller papillae width. The feeding of FO did not negatively impact feedlot performance overall. When MON was added to the diet, cattle had lower DMI overall and 12th rib fat daily gain, and improved gain to feed ratio. The addition of MON to diets improved feedlot performance but reduced the rate of carcass fat deposition. The few effects observed when FO was added to diets were not sufficient to impact feedlot performance.
Becoming Dead: Burial Assemblages as Vitalist Devices
Authors: Fahlander Fredrik
Published: April 2020

This text comprises a critical discussion of assemblage theory and its application to burial studies. In recent research, burials have been viewed as fluid and indeterminate assemblages that ‘become’ in varied ways depending on different perceptions (concepts and ideas) and apparatuses (e.g. excavation tools and measuring instruments). The past and the present are thus mixed in potentially ever-new configurations which run the risk of replacing epistemological relativism with ontological fluidity. It is argued here that the hypothetical mutability of burial assemblages can be reduced significantly by addressing the varying speed and degree of the involved processes of integration and disintegration. By doing this, the main focus is shifted to the animacy of such processes and how they may have been understood and utilized in burials. Using both general and specific examples, it is argued that cremation burials can be studied as carefully compiled amalgamations that utilize the properties and animacies of different materialities to deal with death, corpses and the afterlife.
Investigation of variable storage conditions for cultivated northern wild rice and their effects on seed viability and dormancy
Authors: McGilp Lillian , Duquette Jacques , Braaten Daniel , Kimball Jennifer , Porter Raymond
Published: April 2020

Cultivated northern wild rice (NWR; Zizania palustris L.) has been bred and studied since the 1950s. One challenge facing researchers is the lack of storage options, due to the seed's unorthodox behaviour. This study evaluated varying storage temperature and moisture conditions for the maintenance of seed viability and dormancy breaking in Minnesota-grown NWR. First, seeds were placed in non-submerged, freezing storage (NSFS) for 12–26 weeks, then in submerged, cold storage (SCS) for 2 weeks. The addition of SCS increased germination (%G) relative to NSFS alone (<0.1% NSFS, 15% NSFS and SCS), indicating that NSFS does not kill seeds but also does not break seed dormancy. Next, the required length of SCS was evaluated by placing seeds in NSFS for 12 weeks and then in SCS for 2–14 weeks. A longer SCS period increased %G from 3 to 79%, at 2 and 14 weeks of SCS, respectively. Lastly, seeds were placed in NSFS, followed by SCS, at varying intervals over a 29-week period. Across lines, germination increased from 20 to 76% between 4 and 7 weeks of SCS, respectively, then plateaued. The results of this study indicate that NSFS could be used to store NWR seeds, but at least 7 weeks in SCS is required to overcome dormancy. Additionally, while NSFS did not break seed dormancy, physiological changes related to stratification processes were occurring in non-submerged, freezing conditions. Results also suggest that the genotypic variation in NWR could be utilized for selection to improve germination and storage viability.
Clinical significance of family history and bicuspid aortic valve in children and young adult patients with Marfan syndrome
Authors: Monda Emanuele , Fusco Adelaide , Melis Daniela , Caiazza Martina , Gragnano Felice , Mauriello Alfredo , Cirillo Annapaola , Rubino Marta , Esposito Augusto , Grammegna Angelina , Nistri Stefano , Pepe Guglielmina , Calabrò Paolo , Strisciuglio Pietro , Della Corte Alessandro , Oppido Guido , Russo Mariagiovanna , Limongelli Giuseppe
Published: April 2020

Background:

Marfan syndrome is an autosomal dominant disorder of the connective tissue, whose cardinal features affect eyes, musculoskeletal, and cardiovascular system. Despite prevalence and natural history of cardiovascular manifestation are well known in adults, little is known about children and young adult patients. The aim of this study was to describe a well-characterised cohort of consecutive children and young patients with marfan syndrome, looking at the impact of family history and presence of bicuspid aortic valve on disease severity.

Methods:

A total of 30 consecutive children and young patients with Marfan syndrome were evaluated. All patients underwent a comprehensive clinical–instrumental–genetic evaluation. Particular attention was posed to identify differences in prevalence of cardiovascular abnormalities between patients with and without family history of Marfan syndrome or bicuspid aortic valve.

Results:

Of these 30 patients, family history of Marfan syndrome and bicuspid aortic valve were present in 76 and 13%, respectively. Compared to patients with family history of Marfan syndrome, those without showed higher prevalence of aortic sinus dilation (87 versus 32%, p-value = 0.009), greater aortic sinus diameters (4.2 ± 2.1 versus 1.9 ± 1.1 z score, p-value = 0.002), and higher rate of aortic surgery during follow-up (37 versus 0%, p-value = 0.002). Compared to patients with tricuspid aortic valve, those with bicuspid aortic valve were younger (3.2 ± 4.3 versus 10.7 ± 6.8 years old, p-value = 0.043), showed greater aortic sinus diameters (4.2 ± 0.9 versus 2.2 ± 1.6 z score, p-value = 0.033), and underwent more frequently aortic root replacement (50 versus 4%, p-value = 0.004).

Conclusions:

In our cohort of patients with Marfan syndrome, the absence of family history and the presence of bicuspid aortic valve were associated to severe aortic phenotype and worse prognosis.
Exercise capacity, physical activity, and health-related quality of life in adults with CHD
Authors: Ashman Kröönström Linda , Cider Åsa , Zetterström Anna-Klara , Johansson Linda , Eriksson Peter , Brudin Lars , Dellborg Mikael
Published: April 2020

Objectives:

The aim of this study was to assess exercise capacity, physical activity, and health-related quality of life within a broad and unselected group of adults with CHD.

Design:

From April 2009 to February 2014, 1310 patients were assessed for suitability to participate in this single-centre cross-sectional study. Seven hundred and forty-seven (57%) patients were included, performed a submaximal bicycle test, and answered questionnaires regarding physical activity and health-related quality of life. Exercise capacity, physical activity, and health-related quality of life were compared with reference values and correlations were studied.

Results:

The exercise capacities of men and women with CHD were 58.7 and 66.3%, respectively, of reference values. Approximately, 20–25% of the patients did not achieve the recommended amount of physical activity. In addition, men scored significantly less points on 7 out of 10 scales of health-related quality of life and women in 6 out of 10 scales, compared with reference values. The strongest correlation was between exercise capacity and the Short Form-36 (physical function).

Conclusions:

Exercise capacity was impaired in all adults with CHD, including those with less complicated CHD. One-quarter of the patients did not achieve the recommended levels of physical activity. Exercise tests followed by individualised exercise prescriptions may be offered to all patients with CHD aiming to increase exercise capacity, levels of physical activity, improve health-related quality of life, and reduce the risk of acquired life-style diseases.
ONE-DIMENSIONAL CHAOTIC LAMINAR FLOW WITH COMPETITIVE EXOTHERMIC AND ENDOTHERMIC REACTIONS
Authors: WATT S. D. , HUANG Z. , SIDHU H. S. , MCINTOSH A. C. , BRINDLEY J.
Published: April 2020

We consider the numerical solution of competitive exothermic and endothermic reactions in the presence of a chaotic advection flow. The resulting behaviour is characterized by a strong dependence on the competitive reaction history. The burnt temperature is not immediately connected to simple enthalpy calculations, so there is a subtlety in the interplay between the major parameters, notably the Damköhler number, the ratio of the heats of exothermic and endothermic reactions, as well as the ratio of their respective activation energies. This paper seeks to explore the way these parameters affect the steady states of these reaction fronts and their stability.
A review on circularly polarized antennas, trends and advances
Authors: Banerjee Utsab , Karmakar Anirban , Saha Anuradha
Published: April 2020

This literature presents a comprehensive, technical review of circularly polarized (CP) antennas for different applications in wireless communication, emphasizing on the recent developments in the concerned research. The article also presents a comparative study of various works reported in the open literature, with an aim to highlight the contribution of CP antenna systems in the chronological development of the wireless communication technology. The primary motive of this review is to (a) highlight the methodologies used by different researchers to portray and analyze the different aspects in which CP antennas find their applications in modern-day wireless communication, (b) provide a practical viewpoint of the future scope of the study, based upon the past and present state-of-art research trends and (c) provide a conceptual and technical support to present-day antenna designers to help the process of furtherance of innovation and multiple system integration. In conclusion, the article also throws some light upon the future scope of research in the vast domain of CP antenna applications.
A rectangular slot antenna with perfectly conducting superstrate and reflector sheets for superior radiation in the 6–9 GHz band
Authors: Kumar Ritish , Praveen Kumar A. V.
Published: April 2020

This paper presents the design and analysis of a rectangular slot antenna for producing a directional radiation pattern over a wide bandwidth of 6–9 GHz. A basic wideband slot antenna is designed for the desired frequency band by microstrip offset feed technique. This antenna is then loaded with a superstrate and a reflector, both made of conducting sheets. Analogous to a three-element Yagi antenna, the superstrate enhances the boresight gain, while the reflector improves the front-to-back ratio (FBR) of the basic slot antenna. The antenna is optimized for superior wideband performance with boresight gain ≥5 dBi, peak cross-pol level ≤−10 dB and FBR ≥10 dB, over the −10 dB impedance band of 6–9 GHz, which in this paper is termed as the radiation bandwidth. Prototype measurement demonstrates a radiation bandwidth of 6.05–8.22 GHz (or 30.41%), which is in decent agreement with the simulation.
Integrating cover crops for weed management in the semiarid U.S. Great Plains: opportunities and challenges
Authors: Kumar Vipan , Obour Augustine , Jha Prashant , Liu Rui , Manuchehri Misha R. , Dille J. Anita , Holman John , Stahlman Phillip W.
Published: April 2020

The widespread evolution of herbicide resistance in weed populations has become an increasing concern for no-tillage (NT) growers in semiarid regions of the U.S. Great Plains. Lack of cost-effective and alternative new herbicide sites of action further exacerbates the problem of herbicide-resistant (HR) weeds and threatens the long-term sustainability of prevailing cropping systems in the region. A recent decline in commodity prices and increasing herbicide costs to manage HR weeds has spurred research efforts to build a strong rationale for developing ecologically based integrated weed management (IWM) strategies in the U.S. Great Plains. Integration of cover crops (CCs) in NT dryland production systems potentially offers several ecosystem services, including weed control, soil health improvement, decline in selective pest pressure, and overall reduction in pest management inputs. This review article aims to document the role of CCs for IWM, with emphasis on exploring emerging weed issues; ecological, economic, and agronomic benefits of growing CCs; and constraints preventing adoption of CCs in NT cropping systems in the semiarid Great Plains. We attempt to focus on changes in weed management practices, their long-term impacts on weed seedbanks, weed shifts, and herbicide-resistance evolution in the most common weed species in the region. We also highlight current knowledge gaps and propose new research priorities based on an improved understanding of CC management strategies that will ultimately aid in achieving sustainable weed management goals and preserving natural resources in water-limited environments.
Quantifying Atmospheric Trace Element Deposition Over the Ocean on a Global Scale With Satellite Rainfall Products
Authors: Kadko David , Landing William M. , Buck Clifton S.
Published: April 2020

Atmospheric input of trace element micronutrients to the oceans is difficult to determine, as even with collection of high‐quality aerosol chemical concentrations, such data by themselves cannot yield deposition rates. To transform these concentrations into rates, a method of determining flux by applying an appropriate deposition velocity is required. A recently developed method based on the natural radionuclide 7Be has provided a means to estimate the bulk (wet + dry) deposition velocity (Vb) required for this calculation. Here, water column 7Be inventories and aerosol 7Be concentrations collected during the 2018 US GEOTRACES Pacific Meridional Transect are presented. We use these data together with those from other ocean basins to derive a global relationship between rain rate (m/yr) and bulk deposition velocity (m/day), such that Vb = 999 ± 96 × Rain rate + 1,040 ± 136 (R2 = 0.81). Thus, with satellite‐derived rainfall estimates, a means to calculate aerosol bulk deposition velocities is provided.
Statistical Analysis of Equatorial Plasma Irregularities Retrieved From Swarm 2013–2019 Observations
Authors: Aa Ercha , Zou Shasha , Liu Siqing
Published: April 2020

In this study, we present a statistical analysis of equatorial plasma irregularities (EPIs) by using in situ plasma density measurements of the Swarm constellation from December 2013 to December 2019. The occurrence patterns for both postsunset and postmidnight EPIs with respect to longitude, season, local time, latitude, solar activity, and geomagnetic activity level are investigated. The main findings are as follows: (1) The postsunset/postmidnight EPIs occurrence rates exhibit different longitudinal and seasonal dependence: The postsunset EPIs have the maximum occurrence rate over the American‐Atlantic sectors during the December solstice and equinoxes, and the postmidnight EPIs have the maximum occurrence rate during the June solstice, especially over the African sector. (2) The postsunset EPIs occurrence rates have a positive correlation with solar activity, while the postmidnight EPIs are negatively correlated with it. (3) The latitudinal distribution of EPIs exhibits a double‐peak structure around ±5° magnetic latitude with a more significant peak in the summer hemisphere. (4) The EPIs occurrence rate increases with increasing geomagnetic activity level. (5) The main controlling factors for the distribution of postsunset EPIs are the magnetic declination angle, equatorial vertical E × B drift, and thermospheric zonal wind. For the postmidnight EPIs, the main controlling factors are likely to be atmospheric gravity waves and equatorward thermospheric meridional wind associated with midnight temperature maximum.
Magnetic Field Measurements From Rome During the August–September 1859 Storms
Authors: Blake Seán P. , Pulkkinen Antti , Schuck Peter W. , Nevanlinna Heikki , Reale Oreste , Veenadhari Bhaskara , Mukherjee Shyamoli
Published: April 2020

The geomagnetic storm (or “Carrington event”) of 1–2 September 1859 is one of the largest geomagnetic disturbances on record. At the time, it caused widespread disruption to telegraph systems and was accompanied by aurorae seen overhead as far south as ∼29° magnetic latitude. The magnitude of the Carrington event means it remains a popular subject of study in the field of space weather, despite the sparse magnetic measurements available from the time. One set of measurements that is available is from the Rome observatory (“Collegio Romano,” magnetic latitude ∼38.6°). Here we transcribe these horizontal magnetic field data and convert them to nanoteslas. We find that the device used at Rome had an operational range of around 305 nT. Despite going off‐scale during the storm, the magnetometer at Rome recorded changes of hundreds of nanoteslas per minute and tens of nanoteslas per second in the horizontal magnetic field. Apart from the tabulated data, we also examine the reported off‐scale deviation of 3,000 nT at Rome during the storm. While we could not explicitly locate this reported deviation in the tabulated data, we find that this deviation is comparable to magnetic variations seen at auroral latitudes for modern large magnetic storms, indicating that Rome was in the auroral oval during the morning of 2 September 1859. By comparing this large off‐scale deviation to modern geomagnetic data, we estimate that Rome may have experienced a maximum change of 420 nT min−1.
Simultaneous Observations of ELF/VLF Rising‐Tone Quasiperiodic Waves and Energetic Electron Precipitations in the High‐Latitude Upper Ionosphere
Authors: Zhima Zeren , Huang Jianping , Shen Xuhui , Xia Zhiyang , Chen Lunjin , Piersanti Mirko , Yang Yanyan , Wang Qiao , Zeng Li , Lei Jungang , Chu Wei , Yan Rui , Zhao Shufan , Hu Yunpeng , Guo Feng
Published: April 2020

The quasiperiodic (QP) waves accompanied by simultaneous energetic electron precipitations in the high‐latitude ionosphere were recorded by the sun‐synchronous circular orbit China Seismo‐Electromagnetic Satellite (CSES). The new features of QP waves observed by CSES are the well‐pronounced rising‐tone structures and very short repetition periods, which are not ofen reported by previous studies. The repetition period of QP waves varies from ~1 to over 20 s, with wave spectral properties displaying dynamic structures and clear cutoff frequencies. The majority of QP waves appear at geomagnetic latitudes from ~50° to 65°, and L shell from ~3.5 to 4, mostly inside the plasmapause. The QP waves obliquely propagate towards decreasing L shell directions with right‐handed polarization, with wave normal angles varying from ~30° to 50°. Out of the 68 events examined, 19 of them show synchronous variations of ultralow frequency (ULF) magnetic field pulsations in certain portions of the wave event. The energetic electrons predominately precipitate in a double‐peak pattern (~400 to 550 keV and ~700 to 800 keV). No clear periodic precipitating fluxes were found. The estimated time interval of energetic electrons driving free energy to modulate the whistler‐mode waves varies from 0.04 to 30°s, which is roughly consistent with the observed repetition periods (10 to over 20 s). For the fast repetition period (~1 to 2s) QP wave, it is likely caused by the bouncing of the extremely/very low frequency (ELF/VLF) whistler‐mode wave packets from the conjugate ionosphere.
Planetary Wave (PW) Generation in the Thermosphere Driven by the PW‐Modulated Tidal Spectrum
Authors: Forbes Jeffrey M. , Zhang Xiaoli , Maute Astrid
Published: April 2020

The National Center for Atmospheric Research thermosphere‐ionosphere‐electrodynamics general circulation model (TIE‐GCM) is used to conduct numerical experiments that isolate and elucidate a substantial modification of the quasi‐6‐day wave (Q6DW) above 110 km due to presence of the planetary wave (PW)‐modulated tidal spectrum. A two‐stage nonlinear tidal interaction is proposed, and its role in vertical coupling by the Q6DW is quantified. The theory enables calculation of net Q6DW accelerations and heating rates in the height‐latitude domain (90–300 km; ±75°) due to wave‐wave interactions of up to 10 ms−1 day−1 and 8 K day−1, respectively. The Global‐Scale Wave Model (GSMW) is used to demonstrate that these forcings produce Q6DW zonal and meridional wind amplitudes, and temperatures, of order 5–20 ms−1, 5–15 ms−1, and 5–10 K, respectively. Notably, Q6DW thermal forcing in the GSWM accounts for near‐doubling of the wind magnitudes calculated with momentum forcing alone. The computed values are comparable to the 10–22 ms−1, 3–12 ms−1, and 4–12 KQ6DW amplitudes calculated with lower‐boundary forcing of the Q6DW also included. The proposed two‐stage interaction plausibly impacts other PW wind structures in the dynamo region and thus how PW in general participate in atmosphere‐ionosphere coupling.
Statistical Comparisons of Temperature Variance and Kinetic Energy in Global Ocean Models and Observations: Results From Mesoscale to Internal Wave Frequencies
Authors: Luecke Conrad A. , Arbic Brian K. , Richman James G. , Shriver Jay F. , Alford Matthew H. , Ansong Joseph K. , Bassette Steven L. , Buijsman Maarten C. , Menemenlis Dimitris , Scott Robert B. , Timko Patrick G. , Voet Gunnar , Wallcraft Alan J. , Zamudio Luis
Published: April 2020

Temperature variance and kinetic energy (KE) from two global simulations of the HYbrid Coordinate Ocean Model (HYCOM; 1/12° and 1/25°) and three global simulations of the Massachusetts Institute of Technology general circulation model (MITgcm; 1/12°, 1/24°, and 1/48°), all of which are forced by atmospheric fields and the astronomical tidal potential, are compared with temperature variance and KE from a database of about 2,000 moored historical observations (MHOs). The variances are computed across frequencies ranging from supertidal, dominated by the internal gravity wave continuum, to subtidal, dominated by currents and mesoscale eddies. The most important qualitative difference between HYCOM and MITgcm, and between simulations of different resolutions, is in the supertidal band, where the 1/48° MITgcm lies closest to observations. Across all frequency bands examined, the HYCOM simulations display higher spatial correlation with the MHO than do the MITgcm simulations. The supertidal, semidiurnal, and diurnal velocities in the HYCOM simulations also compare more closely with observations than do the MITgcm simulations in a number of specific continental margin/marginal sea regions. To complement the model‐MHO comparisons, this paper also compares the surface ocean geostrophic eddy KE in HYCOM, MITgcm, and a gridded satellite altimeter product. Consistent with the model‐MHO comparisons, the HYCOM simulations have a higher spatial correlation with the altimeter product than the MITgcm simulations do. On the other hand, the surface ocean geostrophic eddy KE is too large, relative to the altimeter product, in the HYCOM simulations.