bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemical convergence between plants and insects: biosynthetic origins and functions of common secondary metabolites
Authors: Beran Franziska , Köllner Tobias G. , Gershenzon Jonathan , Tholl Dorothea
Published: February 2019

Despite the phylogenetic distance between plants and insects, these two groups of organisms produce some secondary metabolites in common. Identical structures belonging to chemical classes such as the simple monoterpenes and sesquiterpenes, iridoid monoterpenes, cyanogenic glycosides, benzoic acid derivatives, benzoquinones and naphthoquinones are sometimes found in both plants and insects. In addition, very similar glucohydrolases involved in activating two‐component defenses, such as glucosinolates and cyanogenic glycosides, occur in both plants and insects. Although this trend was first noted many years ago, researchers have long struggled to find convincing explanations for such co‐occurrence. In some cases, identical compounds may be produced by plants to interfere with their function in insects. In others, plant and insect compounds may simply have parallel functions, probably in defense or attraction, and their co‐occurrence is a coincidence. The biosynthetic origin of such co‐occurring metabolites may be very different in insects as compared to plants. Plants and insects may have different pathways to the same metabolite, or similar sequences of intermediates, but different enzymes. Further knowledge of the ecological roles and biosynthetic pathways of secondary metabolites may shed more light on why plants and insects produce identical substances.
Wood structure and function change with maturity: Age of the vascular cambium is associated with xylem changes in current‐year growth
Authors: Rodriguez‐Zaccaro F. Daniela , Valdovinos‐Ayala Jessica , Percolla Marta I. , Venturas Martin D. , Pratt R. Brandon , Jacobsen Anna L.
Published: February 2019

Xylem vessel structure changes as trees grow and mature. Age‐ and development‐related changes in xylem structure are likely related to changes in hydraulic function. We examined whether hydraulic function, including hydraulic conductivity and vulnerability to water‐stress‐induced xylem embolism, changed over the course of cambial development in the stems of 17 tree species. We compared current‐year growth of young (1–4 years), intermediate (2–7 years), and older (3–10 years) stems occurring in series along branches. Diffuse and ring porous species were examined, but nearly all species produced only diffuse porous xylem in the distal branches that were examined irrespective of their mature xylem porosity type. Vessel diameter and length increased with cambial age. Xylem became both more conductive and more cavitation resistant with cambial age. Ring porous species had longer and wider vessels and xylem that had higher conductivity and was more vulnerable to cavitation; however, these differences between porosity types were not present in young stem samples. Understanding plant hydraulic function and architecture requires the sampling of multiple‐aged tissues because plants may vary considerably in their xylem structural and functional traits throughout the plant body, even over relatively short distances and closely aged tissues.
Overexpressing broccoli tryptophan biosynthetic genes BoTSB1 and BoTSB2 promotes biosynthesis of IAA and indole glucosinolates
Authors: Li Rui , Jiang Jia , Jia Songyao , Zhu Xingyu , Su Hongzhu , Li Jing
Published: February 2019

Tryptophan is one of the amino acids that cannot be produced in humans and has to be acquired primarily from plants. In Arabidopsis thaliana (Arabidopsis), the tryptophan synthase beta subunit (TSB) genes have been found to catalyze the biosynthesis of tryptophan. Here, we report the isolation and characterization of two TSB genes from Brassica oleracea (broccoli), designated BoTSB1 and BoTSB2. Overexpressing BoTSB1 or BoTSB2 in Arabidopsis resulted in higher tryptophan content and the accumulation of indole‐3‐acetic acid (IAA) and indole glucosinolates in rosette leaves. Therefore, the transgenic plants showed a series of high auxin phenotypes, including long hypocotyls, large plants and a high number of lateral roots. The spatial expression of BoTSB1 and BoTSB2 was detected by quantitative real‐time PCR in broccoli and by expressing the β‐glucuronidase reporter gene (GUS) controlled by the promoters of the two genes in Arabidopsis. BoTSB1 was abundantly expressed in vascular tissue of shoots and inflorescences. Compared to BoTSB1, BoTSB2 was expressed at a very low level in shoots but at a higher level in roots. We further investigated the expression response of the two genes to several hormone and stress treatments. Both genes were induced by methyl jasmonate (MeJA), salicylic acid (SA), gibberellic acid (GA), Flg22 (a conserved 22‐amino acid peptide derived from bacterial flagellin), wounding, low temperature and NaCl and were repressed by IAA. Our study enhances the understanding of tryptophan biosynthesis and its regulation in broccoli and Arabidopsis. In addition, we provide evidence that TSB genes can potentially be a good tool to breed plants with high biomass and high nutrition.
Telling adults about one's plight as a victim of bullying: Student‐ and context‐related factors predicting disclosure
Authors: Blomqvist Katri , Saarento‐Zaprudin Silja , Salmivalli Christina
Published: February 2019

We examined student‐ and context‐related factors related to whether bullied students tell adults about their plight at school or at home. The sample included 1,266 students in primary (Grades 4–6) and lower secondary (Grades 8–9) schools, who had answered an online questionnaire at two measurement points about 5 months apart and were identified as victims of bullying on the basis of the latter. Only 55.4% of the bullied students had told their situation to someone, and much fewer had told an adult. Telling an adult at home was more common (34.0%) than telling a teacher (20.6%) or some other adult at school (12.7%). In a longitudinal structural equation model (SEM), factors related to increased likelihood of telling an adult were female gender, lower grade level, the chronicity of victimization, perceived negative teacher attitude towards bullying (teacher not tolerating bullying), and perceived peer support for victims (classmates’ tendency to defend students who are victimized).
Equine eosinophilic keratoconjunctivitis in California: retrospective study of 47 eyes from 29 cases (1993‐2017)
Authors: Knickelbein Kelly E. , Luethy Daniela , Thomasy Sara M. , Reilly Christopher , Strom Ann R. , Lassaline Mary E.
Published: February 2019

Objective

(a) To evaluate the epidemiology of equine eosinophilic keratoconjunctivitis (EK) in the western United States, (b) to ascertain the efficacy of keratectomy and diamond burr debridement vs medical management alone, (c) to determine the efficacy of various medical therapies, and (d) to further characterize the histopathologic findings of the disease in horses.

Animals studied

Twenty‐nine horses (47 eyes) diagnosed withEKfrom 1993 to 2017.

Procedure

Retrospective medical record review; owner questionnaire.

Results

Average age of presentation was 11 ± 4 years. Warmbloods were significantly overrepresented (P = 0.024). Twenty horses were treated with medical therapy alone, five were treated with superficial lamellar keratectomy, and four were treated with diamond burr debridement. Follow‐up data were available for 38 eyes of 23 horses. Median time to resolution for horses treated with either superficial keratectomy or diamond burr debridement (62 days) was not statistically significantly different from those that underwent medical therapy alone (46 days;P = 0.33). Eyes treated with topical steroids had a statistically significant longer median time to resolution (61 days) compared to those that did not receive topical steroid (44 days;P = 0.023). Common histopathologic findings in keratectomy samples included the presence of eosinophils, vascularization, and an eosinophilic membrane spanning areas of ulceration.

Conclusion

In this population, time toEKresolution was similar for horses treated with medical and surgical management. The use of topical steroids was associated with a prolonged time to resolution. Keratectomy samples from horses withEKhad similar findings to those reported in other species.
Phacoemulsification cataract surgery in the loggerhead turtle (Caretta caretta): surgical technique and outcomes in 10 cases
Authors: Westermeyer Hans D. , Cook Anne G. , Harms Craig , Boylan Shane
Published: February 2019

Cataract removal using phacoemulsification was performed in 10 loggerhead turtles being rehabilitated after stranding. All turtles had significant systemic abnormalities and had cataracts either at the time of rescue or developed them during rehabilitation. Surgical difficulties encountered included an extremely soft globe that did not allow for a partial thickness corneal incision, incomplete topical anesthesia of the ocular surface with proparacaine, inability to dilate the pupil pharmacologically, a markedly shallow anterior chamber, a thick posterior capsular plaque in most cases, and difficulty creating a watertight closure with sutures. Minimal to no intraocular inflammation was seen in all cases following surgery, but all cases in which corneal sutures were used developed a marked inflammatory reaction surrounding the sutures and appeared uncomfortable until sutures were removed or sloughed. All turtles appeared to have improved vision following surgery and were eventually released. Two turtles were re‐encountered a year or more after release. Both showed signs of normal growth and the ability to capture prey in the wild. This report documents successful outcomes associated with cataract surgery in loggerhead turtles, but also presents significant surgical challenges that should be taken into account before attempting this procedure in this species.
Supplementing Western Perspectives of Learner-Centered Instruction With a Daoist Approach Towards Authentic Power Sharing in the Classroom
Authors: Jeffrey David M. , Clark Renee M.
Published: February 2019

Learner-centered teaching (LCT) has one main focus – learners and learning! With learner-centered teaching, the traditional roles of the instructor and learners change. In this paper, we draw various parallels between learner-centered instruction and ancient Chinese wisdom based on Daoist perspectives to further promote and support learner-centered teaching among instructors, in particular college instructors. Daoist wisdom is a philosophy based on living in peace and harmony with the way everything is in nature, and it encourages sharing of power with students, which ultimately engenders trust. This paper will present and discuss the key characteristics of learner-centered instruction alongside ancient Daoist perspectives that align with and promote and support this type of instruction. These learner-centered characteristics include 1) the instructor as a facilitator of learning, 2) sharing of power and control with learners, 3) student participation and responsibility for learning, 4) collaboration among learners, 5) higher-order skills instruction and development, and 6) evaluation for learning purposes. This paper is organized based on these interrelated and interdependent characteristics of LCT and their relationship to ancient Daoist perspectives, which can support instructors in applying learner-centered instructional methods.
Global Aid in the Water Sector: A Descriptive Analysis of International Development Effectiveness
Authors: Hargrove Andrew
Published: February 2019

This study analyzes the intent and effectiveness of international development aid through a content/trend analysis of over 42,000 aid projects in the water supply and sanitation sector. The water sector is a vital and understudied component of international development that is rife with internal contradictions. On the one hand, access to water is rapidly increasing cross-nationally, but over 700 million still lack improved access to water. On the other hand, renewable freshwater resources per capita are rapidly decreasing, and annual freshwater withdrawals are steadily increasing. These concurrent issues lead to water stress and decreased freshwater sustainability, which in turn affects global political, ecological, and health issues. To address these issues, national governments and multinational aid agencies have been lending to the water supply and sanitation sector since 1950. This study assesses the trends in international aid over the past 65 years for their intent and effectiveness in solving global water and development issues. The results have implications for the development effectiveness of nations’ and organizations’ aid and calls for social scientists to investigate well-being and environmental impacts simultaneously in all sectors of development.
Effects of an Active Learning Approach on Students’ Motivation in an Engineering Course
Authors: Tendhar Chosang , Singh Kusum , Jones Brett D.
Published: February 2019

Because there are many positive effects of active learning approaches on students’ motivation and achievement, some authors have recommended that these approaches be widely implemented. A research-intensive university located in the Mid-Atlantic US was interested in adopting this instructional technique, and therefore, experimented with it. The purpose of this quasi-experimental study was to compare and contrast the effects of an active learning approach on the motivation of students in a treatment and control group. The results of multiple independent sample t-tests showed that there were no statistically significant differences between the two groups on several motivation constructs. We provide explanations for the lack of significant differences, as well as discuss limitations and future research.
Selección de hospital destino para el traslado de urgencia de pacientes
Authors: Rojas Cortés Viviana , Romero Laura , Barrera David , Suárez Daniel Ricardo
Published: February 2019

El tiempo total de atención prehospitalaria (APH) es el tiempo que transcurre desde que ingresa la llamada al operador hasta que la ambulancia queda disponible para atender otra emergencia. Esta investigación pretende demostrar que la selección del hospital destino afecta de manera significativa el tiempo total de APH, lo que influye en la supervivencia del paciente que es trasladado y en el tiempo de liberación del recurso (ambulancias). En consecuencia, se propone una técnica de selección de hospital destino que incluye dimensiones relacionadas con el paciente (diagnóstico, especialidad y asegurador) y el hospital (ocupación y cercanía). Se evalúa su desempeño por medio de una simulación de eventos discretos y se concluye que la técnica propuesta obtiene un mejor tiempo de APH en el 73 % de los casos estudiados, con una reducción media entre 40 y 80 minutos, en comparación con la técnica más comúnmente usada (selección hospital más cercano).
Windy season fails to revive fading Mars rover
Authors: Voosen Paul
Published: February 2019

Decision to end Opportunity mission could come in weeks.
Algae suggest eukaryotes get many gifts of bacteria DNA
Authors: Pennisi Elizabeth
Published: February 2019

Analysis revives debate on "horizontal gene transfer."
Identification of site-specific isotopic labels by vibrational spectroscopy in the electron microscope
Authors: Hachtel Jordan A. , Huang Jingsong , Popovs Ilja , Jansone-Popova Santa , Keum Jong K. , Jakowski Jacek , Lovejoy Tracy C. , Dellby Niklas , Krivanek Ondrej L. , Idrobo Juan Carlos
Published: February 2019

Mapping isotopically labeled alanine

Electron microscopy of organic materials must avoid the destructive effects of electron beam impact. One approach is to measure vibrational spectra with electron energy-loss spectroscopy in a mode where the electron beam grazes the sample and couples to it through evanescent modes. Hachtel
et al.
used such methods to probe carbon-12– and carbon-13–labeled alanine crystals, which exhibited an isotopic shift in the asymmetric carbon-oxygen stretching mode. They used this property to map the distribution of labeled clusters of alanine on length scales of tens of nanometers.

Science
, this issue p.
525
Electronic structure in the transition metal block and its implications for light harvesting
Authors: McCusker James K.
Published: February 2019

Transition metal–based chromophores play a central role in a variety of light-enabled chemical processes ranging from artificial solar energy conversion to photoredox catalysis. The most commonly used compounds include elements from the second and third transition series (e.g., ruthenium and iridium), but their Earth-abundant first-row analogs fail to engage in photoinduced electron transfer chemistry despite having virtually identical absorptive properties. This disparate behavior stems from fundamental differences in the nature of 3d versus 4d and 5d orbitals, resulting in an inversion in the compounds’ excited-state electronic structure and undermining the ability of compounds with first-row elements to engage in photoinduced electron transfer. This Review will survey the key experimental observations establishing this difference in behavior, discuss the underlying reasons for this phenomenon, and briefly summarize efforts that are currently under way to alter this paradigm and open the door to new opportunities for using Earth-abundant materials for photoinduced electron transfer chemistries.
Taking a close look at ocean circulation
Authors: Rhein Monika
Published: February 2019

Ocean circulation patterns in the North Atlantic provide a benchmark for climate models
Lymph-node-first Kawasaki disease and giant coronary artery aneurysm
Authors: Ramly Bazlin
Published: February 2019

A 8-year-old Irish ethnicity girl presented with 3 days of fever with right-sided neck swelling which was first thought as acute tonsillitis with right-sided lymphadenitis. She was started on intravenous antibiotics. At day 7 of illness, she was diagnosed to have Kawasaki disease with clinical and biochemical evidence. Echocardiogram at day 9 of illness and subsequently CT cardiac angiogram performed revealed giant aneurysm at the right coronary artery with non-obstructing thrombus seen. The patient then commenced on clopidogrel and continued with a regular dose of aspirin. Due to the evidence of thrombus with a giant coronary aneurysm, she was also put on long-term warfarin therapy with regular monitoring of her international normalised ratio to be kept at the range of 2.0–3.0.
Long-lasting response to afatinib that persisted after treatment discontinuation in a case ofEGFR-mutated lung adenocarcinoma
Authors: Yamanaka Yumie , Seki Yoshitaka , Ishikawa Takeo , Kuwano Kazuyoshi
Published: February 2019

It is unknown whether tyrosine kinase inhibitors targeting epidermal growth factor receptor (EGFR) can be discontinued in patients in whomEGFR-mutated lung cancer has well stabilised. We present a case of a 73-year-old Japanese woman with no history of smoking. Right pulmonary lower lobectomy, lymph node dissection and segmental resection of the right middle lobe were performed. Additionally, she underwent adjuvant chemotherapy for stage IIIB adenocarcinoma harbouring anEGFRexon 19 deletion. Afatinib was administered for liver metastases after 15 months. A complete response of metastatic disease was achieved for 2 years. However, afatinib was unavoidably discontinued due to splenectomy for the treatment of idiopathic thrombocytopenic purpura. Although afatinib was not resumed, due to the abscess formation as surgery complication, a drug-free complete response was sustained for over 18 months. The present case suggests that exceptional and durable responses to afatinib can be achieved in individual cases.
Ectopic varices masquerading as lower gastrointestinal bleeding
Authors: Gheorghiu Alina Cristiana , Proserpio Michele , Regusci Luca , Pagnamenta Alberto
Published: February 2019

A middle-aged woman previously in good health arrived to hospital with severe haemorrhagic shock. An abdominal and pelvic CT scan showed hepatomegaly, fluid in the sigmoid colon, perigastric and right sided pelvic varices without a clear source of bleeding. Urgent esophagogastroduodenoscopy excluded gastric varices and active upper gastrointestinal bleeding and the colonoscopy was inconclusive due to haemodynamic instability and massive bleeding which made it impossible to proceed with a full colonoscopy. An explorative laparotomy identified liver cirrhosis and bleeding from varices of the right fallopian tube which had formed a fistula with the caecum. A right hemicolectomy with a side to side anastomosis and a right sided salpingo-oophorectomy were carried out. The patient was thereafter transferred to the intensive care unit intubated, requiring massive fluid resuscitation and high doses of vasoactive agents. Nine days after hospital admission she was transferred to the surgical ward and followed up by a hepatologist.
Rapid early rise in heart rate on treadmill exercise in patients with asymptomatic moderate or severe aortic stenosis: a new prognostic marker?
Authors: Chambers John B , Rajani Ronak , Parkin Denise , Saeed Sahrai
Published: February 2019

Objective

To examine the clinical significance and prognostic value of an early rapid rise in heart rate (RR-HR) in asymptomatic patients with moderate or severe aortic stenosis (AS).

Methods

We retrospectively assessed the prospectively collected data from 306 patients (age 65±12 years, 33% women) with moderate (n=204) or severe AS (n=102) with a median follow-up of 25 months (mean 34.9±34.6 months). All had echocardiography and modified Bruce exercise treadmill tests (ETT). RR-HR was defined as achieving 85% target HR or ≥50% increase from baseline in the first 6 min. The outcome measures were revealed symptoms during ETT, aortic valve replacement (AVR) and all-cause mortality.

Results

RR-HR occurred in 77 (25%) and 64% developed revealed symptoms (postive predictive value 64% and negative predictive value 84%). On univariate Cox regression analyses in patients with severe AS, RR-HR was associated with AVR (HR 3.32, 95% CI 2.03 to 5.45, p<0.001) but not with all-cause mortality (HR 0.04, 95% CI 0.13 to 9.21, p=0.798). In patients with moderate AS, RR-HR was associated with all-cause mortality (HR 2.67, 95% CI 1.09 to 6.56, p=0.032), but not with AVR (HR 1.35, 95% CI 0.92 to 1.98, p=0.127). These associations remained significant in multivariate Cox regression analyses after adjustment for age, sex, hypertension, coronary artery disease, abnormal blood pressure response, Doppler stroke volume and mean pressure gradient (both p<0.001).

Conclusions

RR-HR was associated with the development of revealed symptoms. It predicted revealed symptoms on serial ETT, AVR in severe AS and all-cause mortality in moderate AS. RR-HR may be a useful new measure to define risk in AS.
Acute hyperkalaemia in a captive Persian leopard (Panthera pardus saxicolor) immobilised with a ketamine‐medetomidine combination
Authors: Diez Bernal Sabina , Hoby Stefan , Levionnois Olivier Louis Raymond
Published: February 2019

A 12‐year‐old captive male Persian leopard (Panthera pardus saxicolor) required general anaesthesia for examination and treatment of a recurrent oral fistula. Medetomidine (0.065 mg/kg) and ketamine (3.6 mg/kg) administered intramuscularly by blowpipe darting effectively immobilised the animal that was maintained under general anaesthesia with inhaled isoflurane. In absence of clinical signs, acute hyperkalaemia (7.26 mmol/l) was incidentally recognised by the end of anaesthesia. Factors that might have played a role in hyperkalaemia development, such as the use of α2‐adrenoceptor agonists, stress response, acidosis or dopamine administration, are discussed. Hyperkalaemia should be considered as a potential complication while anaesthetising large non‐domestic felids.
Inhibitory effect of rosemary essential oil, loaded in liposomes, on seed germination of Acacia saligna, an invasive species in Mediterranean ecosystems
Authors: Maccioni Alfredo , Santo Andrea , Falconieri Danilo , Piras Alessandra , Manconi Maria , Maxia Andrea , Bacchetta Gianluigi
Published: February 2019

Acacia saligna (Labill.) Wendl. is native of southwestern Australia, but has been planted extensively in many areas of the world, including the Mediterranean region, becoming highly invasive especially in coastal habitats. The aim of this study was to test whether the indigenous Rosmarinus officinalis L. essential oil (EO), loaded in liposomes, can inhibit the seed germination of the invasive alien Acacia saligna. Variability in seed germination requirements and responses among populations were evaluated. Germination tests under light, at constant temperatures and three concentrations of rosemary EO were carried out. Among the examined factors, only the EO amount and temperature had a highly significant effect on seed germination. The lowest EO quantity did not show differences compared with the control, while the highest amount inhibited significantly seed germination of all populations at all the tested temperatures. No seed recovered the ability to germinate after the EO treatment with either of the two washing methods. Our results allowed us to identify the minimum amount of rosemary EO capable of inhibiting the seed germination of the invasive Acacia saligna. These results could be useful for the control of this invasive alien species, thus allowing the conservation of indigenous Mediterranean plant species and habitats.
Analysis of load distribution and contact stiffness of the single-nut ball screw based on the whole rolling elements model
Authors: Chen Ye , Zhao Chun-yu , Zhang Si-yu , Meng Xian-li
Published: February 2019

This paper aims to investigate the load distribution and contact stiffness characteristics of the single-nut ball screw pair (SNBSP). First, the transformed relationship of coordinate systems is established. Then, the whole rolling elements load distribution model of the SNBSP is presented. Based on this, the whole rolling elements contact stiffness model is obtained. Applying the Newton–Raphson iterative method to solve the model, the normal force of rolling elements and the contact angles between balls and raceway surface are determined. The calculation results are reasonably consistent with those of the half pitch model. Then, the local contact stiffness and global contact stiffness are obtained. Furthermore, the effects of axial load and structural parameters of the SNBSP on the normal contact force, contact angle, and local and global contact stiffness are discussed using numeric analysis. Finally, a dynamic model of the z-axis feed system with time-varying axial stiffness is established, and the accuracy of the model is verified by experiments.
QUANTITATIVE EASING POLICY, EXCHANGE RATES AND BUSINESS ACTIVITY BY INDUSTRY IN JAPAN FROM 2001 TO 2006
Authors: IJIRI HIROYUKI , MATSUBAYASHI YOICHI
Published: February 2019

This study empirically investigates the dynamic effects of Japan’s quantitative easing (QE) policy on industry-specific business activity using a time-varying parameter model and monthly data spanning 2001–2006. This model yields more reliable and precise results than earlier fixed effects models using quarterly data. The first major finding is that the effect of QE on yen–dollar exchange rates varied during the sampled period and is most evident in the final phases, whereas its effect on stock prices persisted almost continuously. Second, QE’s effect on Japan’s real economy — i.e., on industrial production — varies by industry and over time. Most notably, QE raised production via yen–dollar depreciation in the machinery sector (e.g., general and transport machinery) and the sector including chemicals, non-ferrous metals and iron and steel during its latter phases. This study is the first to investigate how unconventional monetary policy influences Japan’s real economy by analyzing the real exchange rate during the second half of QE implementation in Japan.
Effect of Oxygen Vacancy on Structural, Optical and Magnetic Behavior of Tin Oxide Nanoparticles
Authors: Dinesh M. , Ravindran R. , Rukkumani V. , Srinivasan K. , Saravanakumar M.
Published: February 2019

Nanocrystalline SnO2powder has been successfully synthesized by using tin(II) chloride dihydrate (SnCl[Formula: see text]H2O), distilled water and liquid ammonia by the simple chemical co-precipitation method at room temperature using different SnCl[Formula: see text]H2O molar concentration of 0.3[Formula: see text]M, 0.4[Formula: see text]M and 0.5[Formula: see text]M. The structural properties of the prepared SnO2and transition metal doped SnO2nanoparticles has been studied using X-ray diffraction method and scanning electron microscope. The composition of the powders has been analyzed using energy dispersive X-ray analysis. The XRD pattern of the SnO2nanoparticles indicates the formation of single-phase rutile tetragonal structure. The grain size is found to be in the range of 3–7[Formula: see text]nm and is found to increase with increasing SnCl2molar concentration. The absorption spectra revealed that the bandgap decreased from 3.74[Formula: see text]eV to 3.59[Formula: see text]eV with increasing SnCl2molar concentration. The photoluminescence spectra of SnO2nanoparticles showed a visible broad luminescence band in the region of 385–430[Formula: see text]nm. The magnetic studies have been carried out using the hysteresis loop obtained from a vibrating sample magnetometer. The SnO2samples using 0.3 and 0.4 SnCl2molar concentration exhibited ferromagnetic behavior whereas the SnO2sample prepared using 0.5[Formula: see text]M SnCl[Formula: see text]H2O exhibited paramagnetic nature.
A new approach in interpreting some mock theta functions
Authors: Sharma S. , Rana M.
Published: February 2019

We are applying a new approach to interpret the generalized version of order 8 mock theta functions [Formula: see text] and [Formula: see text] in terms of [Formula: see text]-color partitions. In literature, we find the interpretations of these functions in terms of split [Formula: see text]-color partitions and signed partitions. In addition, we are interpreting the generalized versions of two mock theta functions of order 6 and two of order 5 in terms of [Formula: see text]-color partitions. A mock theta function of order 3 is interpreted in terms of [Formula: see text]-color partitions. We further extend our results using lattice paths.
Spin-Transfer Torques in One-Dimensional Magnetic Tunneling Junctions of Lateral Structures
Authors: Chiou Kuan-Ru , Chen Jenq-Wei , Chen Son-Hsien
Published: February 2019

Recent study in [C. C. Lin, Y. F. Gao, A. V. Penumatcha, V. Q. Diep, J. Appenzeller and Z. H. Chen, Acs Nano 8, 3807 (2014)], showed that the spin-transfer torque (STT) is enhanced by the asymmetry in a graphene lateral spin-valve structure. This lateral structure or geometry can be modeled by a four-terminal magnetic tunneling junction (MTJ) as opposite to the conventional two-terminal MTJ. In this paper, using the nonequilibrium Green’s function formalism (NEGF), we compare the anti-damping components of the STT in a similar nonconventional lateral one-dimensional MTJ with that in the conventional MTJ. We find that the lateral geometry renders enhanced anti-damping torques compared with the conventional one, provided that the barrier energy, the scattering length and the magnetization angle are in a certain parameter region. We also identify this parameter region in the presence of dephasing. The enhancement of the anti-damping torques declines when the scattering region is longer. For the four-terminal MTJ of larger scattering length, the dephasing can expedite the anti-damping torque.
Implementing RFI Mitigation in Radio Science
Authors: Baan Willem A.
Published: February 2019

This paper presents an overview of methods for mitigating radio frequency interference (RFI) in radio science data. The primary purpose of mitigation is to assist observatories to take useful data outside frequency bands allocated to the Science Services (Radio Astronomy Service (RAS) and Earth Exploration Service (EESS)): mitigation should not be needed within passive bands. Mitigation methods may be introduced at a variety of points within the data acquisition system in order to lessen the RFI intensity and to limit the damage it causes. These methods range from proactive methods to changing the local RFI environment by means of regulatory manners, to pre- and post-detection methods, to various pre-processing methods, and to methods applied at or post-processing.
Discrete breathers modeling from first principles in graphene and in classical approximation in fcc Ni: Comparison
Authors: Lobzenko Ivan P.
Published: February 2019

Properties of discrete breathers are discussed from two points of view: (I) the ab initio modeling in graphene and (II) classical molecular dynamics simulations in the ace-centered cubic (fcc) Ni. In the first (I) approach, the possibility of exciting breathers depends on the strain applied to the graphene sheet. The uniaxial strain leads to opening the gap in the phonon band and, therefore, the existence of breathers with frequencies within the gap. In the second (II) approach, the structure of fcc Ni supports breathers of another kind, which possess a hard nonlinearity type. It is shown that particular high frequency normal mode can be used to construct the breather by means of overlaying a spherically symmetrical function, the maximum of which coincides with the breather core. The approach of breathers excitation based on nonlinear normal modes is independent of the level of approximation. Even though breathers could be obtained both in classical and first-principles calculations, each case has advantages and shortcomings, that are compared in the present work.
Sex differences in cerebral autoregulation are unaffected by menstrual cycle phase in young, healthy women
Authors: Favre Michelle E. , Serrador Jorge M.
Published: February 2019

Sex is known to affect the prevalence of conditions such as stroke. However, effects of sex on cerebral blood flow regulation are still not well understood. Critical to this understanding is how fluctuations in hormones across the menstrual cycle affect cerebral autoregulation. We measured autoregulation in the early follicular, late follicular, and midluteal phases during spontaneous and induced blood pressure oscillations in 26 young, healthy individuals (13 women and 13 men, age: 26 ± 4 yr). Men participated three times, ~1–3 wk apart. Beat-by-beat blood pressure, heart rate, end-tidal CO2, and transcranial Doppler ultrasonography of the middle (MCA) and anterior (ACA) cerebral arteries were obtained. We did not find a difference in cerebral autoregulation across the menstrual cycle in women but found significantly improved autoregulation in the MCA and ACA of women compared with men. Women demonstrated significantly lower MCA gain (0.97 ± 0.13 vs. 1.17 ± 0.14%/mmHg, P = 0.001), higher MCA phase (46.1 ± 12.6 vs. 35.8 ± 7.9°, P = 0.019), and higher ACA phase (40.5 ± 10.8 vs 31.5 ± 8.5°, P = 0.040) during repeated squat-to-stand maneuvers. Women also had lower MCA gain (1.50 ± 0.11 vs. 1.72 ± 0.30%/mmHg, P = 0.029) during spontaneous fluctuations in pressure while standing and less of a decrease in MCA flow velocity (−18.7 ± 2.7 vs. −23.2 ± 6.0%, P = 0.014) during sit-to-stand maneuvers. Our results suggest that young women have improved cerebral autoregulation compared with young men regardless of menstrual cycle phase and that autoregulation is relatively robust to acute fluctuations in female sex hormones.

NEW & NOTEWORTHY This is the first study to investigate thoroughly the effects of menstrual cycle phase and sex differences in cerebral autoregulation in young, healthy individuals. Cerebral autoregulation was unaffected by menstrual cycle phase during both repeated squat-to-stand and sit-to-stand maneuvers. However, women demonstrated significantly improved cerebral autoregulation in the middle and anterior cerebral arteries, suggesting women were able to maintain cerebral blood flow during changes in blood pressure more efficiently than men.
Important roles of endothelial caveolin-1 in endothelium-dependent hyperpolarization and ischemic angiogenesis in mice
Authors: Ito Akiyo , Shiroto Takashi , Godo Shigeo , Saito Hiroki , Tanaka Shuhei , Ikumi Yosuke , Kajitani Shoko , Satoh Kimio , Shimokawa Hiroaki
Published: February 2019

Although increased levels of reactive oxygen species (ROS) are involved in the pathogenesis of cardiovascular diseases, the importance of physiological ROS has also been emerging. We have previously demonstrated that endothelium-derived H2O2 is an endothelium-dependent hyperpolarization (EDH) factor and that loss of endothelial caveolin-1 reduces EDH/H2O2 in the microcirculation. Caveolin-1 (Cav-1) is a scaffolding/regulatory protein that interacts with diverse signaling pathways, including angiogenesis. However, it remains unclear whether endothelial Cav-1 plays a role in ischemic angiogenesis by modulating EDH/H2O2. In the present study, we thus addressed this issue in a mouse model of hindlimb ischemia using male endothelium-specific Cav-1 (eCav-1) knockout (KO) mice. In isometric tension experiments with femoral arteries from eCav-1-KO mice, reduced EDH-mediated relaxations to acetylcholine and desensitization of sodium nitroprusside-mediated endothelium-independent relaxations were noted ( n = 4~6). An ex vivo aortic ring assay also showed that the extent of microvessel sprouting was significantly reduced in eCav-1-KO mice compared with wild-type (WT) littermates ( n = 12 each). Blood flow recovery at 4 wk assessed with a laser speckle flowmeter after femoral artery ligation was significantly impaired in eCav-1-KO mice compared with WT littermates ( n = 10 each) and was associated with reduced capillary density and muscle fibrosis in the legs ( n = 6 each). Importantly, posttranslational protein modifications by reactive nitrogen species and ROS, as evaluated by thiol glutathione adducts and nitrotyrosine, respectively, were both increased in eCav-1-KO mice ( n = 6~7 each). These results indicate that endothelial Cav-1 plays an important role in EDH-mediated vasodilatation and ischemic angiogenesis through posttranslational protein modifications by nitrooxidative stress in mice in vivo.

NEW & NOTEWORTHY Although increased levels of reactive oxygen species (ROS) are involved in the pathogenesis of cardiovascular diseases, the importance of physiological ROS has also been emerging. The present study provides a line of novel evidence that endothelial caveolin-1 plays important roles in endothelium-dependent hyperpolarization and ischemic angiogenesis in hindlimb ischemia in mice through posttranslational protein modifications by reactive nitrogen species and ROS in mice in vivo.
The Deubiquitylase OTUB1 Mediates Ferroptosis via Stabilization of SLC7A11
Authors: Liu Tong , Jiang Le , Tavana Omid , Gu Wei
Published: February 2019

Although cell-cycle arrest, senescence, and apoptosis are established mechanisms of tumor suppression, accumulating evidence reveals that ferroptosis, an iron-dependent, nonapoptotic form of cell death, represents a new regulatory pathway in suppressing tumor development. Ferroptosis is triggered by lipid peroxidation and is tightly regulated by SLC7A11, a key component of the cystine-glutamate antiporter. Although many studies demonstrate the importance of transcriptional regulation of SLC7A11 in ferroptotic responses, it remains largely unknown how the stability of SLC7A11 is controlled in human cancers. In this study, we utilized biochemial purification to identify the ubiquitin hydrolase OTUB1 as a key factor in modulating SLC7A11 stability. OTUB1 directly interacted with and stabilized SLC7A11; conversely, OTUB1 knockdown diminished SLC7A11 levels in cancer cells. OTUB1 was overexpressed in human cancers, and inactivation of OTUB1 destabilized SLC7A11 and led to growth suppression of tumor xenografts in mice, which was associated with reduced activation of ferroptosis. Notably, overexpression of the cancer stem cell marker CD44 enhanced the stability of SLC7A11 by promoting the interaction between SLC7A11 and OTUB1; depletion of CD44 partially abrogated this interaction. CD44 expression suppressed ferroptosis in cancer cells in an OTUB1-dependent manner. Together, these results show that OTUB1 plays an essential role in controlling the stability of SLC7A11 and the CD44-mediated effects on ferroptosis in human cancers.

Significance:

This study identifies OTUB1 as a key regulator of ferroptosis and implicates it as a potential target in cancer therapy.

See related commentary by Gan, p. 1749
Eomes+T-betlow CD8+ T Cells Are Functionally Impaired and Are Associated with Poor Clinical Outcome in Patients with Acute Myeloid Leukemia
Authors: Jia Bei , Zhao Chenchen , Rakszawski Kevin L. , Claxton David F. , Ehmann W. Christopher , Rybka Witold B. , Mineishi Shin , Wang Ming , Shike Hiroko , Bayerl Michael G. , Sivik Jeffrey M. , Schell Todd D. , Drabick Joseph J. , Hohl Raymond J. , Zheng Hong
Published: February 2019

Acute myeloid leukemia (AML) is a devastating blood cancer with poor prognosis. Immunotherapy targeting inhibitory pathways to unleash the antileukemia T-cell response is a promising strategy for the treatment of leukemia, but we must first understand the underlying molecular mechanisms. Eomesodermin (Eomes) and T-bet are both T-box transcription factors that regulate CD8+ T-cell responses in a context-specific manner. Here, we examined the role of these transcription factors in CD8+ T-cell immunity in AML patients. We report that the frequency of Eomes+T-betlow CD8+ T cells increased in newly diagnosed AML. This cell subset produced fewer cytokines and displayed reduced killing capacity, whereas depletion of Eomes by siRNA reversed these functional defects. Furthermore, Eomes bound the promoter of T-cell immunoglobulin and ITIM domain (TIGIT) and positively regulated the expression of this inhibitory receptor on patient-derived T cells. A high frequency of Eomes+T-betlow CD8+ T cells was associated with poor response to induction chemotherapy and shorter overall survival in AML patients. These findings have significant clinical implications as they not only identify a predictive and prognostic biomarker for AML, but they also provide an important target for effective leukemia therapeutics.

Significance:

These findings reveal that a high frequency of Eomes+T-betlow CD8+ T cells predicts poor clinical outcome in AML and that targeting Eomes may provide a therapeutic benefit against AML.
Epigenetic Drift in Colorectal Cancer—It's Probably Later Than You Think
Authors: Sapienza Carmen
Published: February 2019

The analysis of age-related methylation changes in patients with colorectal cancer indicates that tumors have their origins earlier in life than previously suspected. The implication is that healthy lifestyle modifications designed to prevent colorectal cancer should be adopted early in life.

See related article by Luebeck et al., p. 495
Genetic Variation in Steroid and Xenobiotic Metabolizing Pathways and Enterolactone Excretion Before and After Flaxseed Intervention in African American and European American Women
Authors: Chang Huiru , Yao Song , Tritchler David , Hullar Meredith A. , Lampe Johanna W. , Thompson Lilian U. , McCann Susan E.
Published: February 2019

Background:

Metabolism and excretion of the phytoestrogen enterolactone (ENL), which has been associated with breast cancer risk, may be affected by variation in steroid hormone and xenobiotic-metabolizing genes.

Methods:

We conducted a randomized, crossover flaxseed intervention study in 252 healthy, postmenopausal women [137 European ancestry (EA) and 115 African ancestry (AA)] from western New York. Participants were randomly assigned to maintain usual diet or consume 10 g/day ground flaxseed for 6 weeks. After a 2-month washout period, participants crossed over to the other diet condition for an additional 6 weeks. Urinary ENL excretion was measured by gas chromatography-mass spectrometry and 70 polymorphisms in 29 genes related to steroid hormone and xenobiotic metabolism were genotyped. Mixed additive genetic models were constructed to examine association of genetic variation with urinary ENL excretion at baseline and after the flaxseed intervention.

Results:

SNPs in several genes were nominally (P < 0.05) associated with ENL excretion at baseline and/or after intervention: ESR1, CYP1B1, COMT, CYP3A5, ARPC1A, BCL2L11, SHBG, SLCO1B1, and ZKSCAN5. A greater number of SNPs were associated among AA women than among EA women, and no SNPs were associated in both races. No SNP–ENL associations were statistically significant after correction for multiple comparisons.

Conclusions:

Variation in several genes related to steroid hormone metabolism was associated with lignan excretion at baseline and/or after flaxseed intervention among postmenopausal women.

Impact:

These findings may contribute to our understanding of the differences observed in urinary ENL excretion among AA and EA women and thus hormone-related breast cancer risk.
Simultaneous Measurement of 92 Serum Protein Biomarkers for the Development of a Multiprotein Classifier for Ovarian Cancer Detection
Authors: Skubitz Amy P.N. , Boylan Kristin L.M. , Geschwind Kate , Cao Qing , Starr Timothy K. , Geller Melissa A. , Celestino Joseph , Bast Robert C. , Lu Karen H. , Koopmeiners Joseph S.
Published: February 2019

The best known ovarian cancer biomarker, CA125, is neither adequately sensitive nor specific for screening the general population. By using a combination of proteins for screening, it may be possible to increase the sensitivity and specificity over CA125 alone. In this study, we used Proseek Multiplex Oncology II plates to simultaneously measure the expression of 92 cancer-related proteins in serum using proximity extension assays. This technology combines the sensitivity of the PCR with the specificity of antibody-based detection methods, allowing multiplex biomarker detection and high-throughput quantification. We analyzed 1 μL of sera from each of 61 women with ovarian cancer and compared the values obtained with those from 88 age-matched healthy women. Principle component analysis and unsupervised hierarchical clustering separated the ovarian cancer patients from the healthy, with minimal misclassification. Data from the Proseek plates for CA125 levels exhibited a strong correlation with clinical values for CA125. We identified 52 proteins that differed significantly (P < 0.006) between ovarian cancer and healthy samples, several of which are novel serum biomarkers for ovarian cancer. In total, 40 proteins had an estimated area under the ROC curve of 0.70 or greater, suggesting their potential to serve as biomarkers for ovarian cancer. CA125 alone achieved a sensitivity of 93.4% at a specificity of 98%. By adding the Oncology II values for five proteins to CA125 in a multiprotein classifier, we increased the assay sensitivity to 98.4% at a specificity of 98%, thereby improving the sensitivity and specificity of CA125 alone.