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be an elliptic curve. For a prime p of good reduction, let
be the smallest non-negative integer that gives the x-coordinate of a point of maximal order in the group
. We prove unconditionally that
$r(E,p)> 0.72\log \log p$
for infinitely many p, and
$r(E,p)> 0.36 \log p$
under the assumption of the Generalized Riemann Hypothesis. These can be viewed as elliptic curve analogues of classical lower bounds on the least primitive root of a prime.
Laboratory experiments are conducted to investigate the mechanism controlling the formation of stable and unstable acoustic fountains at the free surface of a quiescent body of water. Fountains are induced by focused ultrasonic, a new modality that allows for better spatiotemporal control of water flow. Particle image velocimetry was used to characterize the induced flow field in the vicinity of the ultrasonic focal spot. We used two types of ultrasonic transducers with distinct wave frequencies. We examined three fountain formation regimes by varying the pressure level of the transducers, namely weak, intermediate (stable) and highly forced fountains (explosive). Between different regimes, the fountain height underwent a step-change in response to the increase in acoustic pressure. A force estimation obtained from the flow field shows that the magnitude of axial momentum flux is orders of magnitude lower than that of gravity and surface tension, indicating that the dominant driving force for the fountain generation is the acoustic radiation force (Nightingale et al., Ultrasound Med. Biol., vol. 28, 2002, pp. 227–235). We propose a simple model to estimate the shape of a stable fountain; it accounts for the applied acoustic pressure, gravity, surface tension and axial momentum. The model neglects viscous force, which precludes capturing the intermediate fountain surface curvature. However, the model successfully predicts the geometry of the weak and intermediate fountains.
In order to maximize the utility of future studies of trilobite ontogeny, we propose a set of standard practices that relate to the collection, nomenclature, description, depiction, and interpretation of ontogenetic series inferred from articulated specimens belonging to individual species. In some cases, these suggestions may also apply to ontogenetic studies of other fossilized taxa.
The coronavirus disease 2019 (COVID-19) pandemic has led to significant strain on front-line healthcare workers.
In this multicentre study, we compared the psychological outcomes during the COVID-19 pandemic in various countries in the Asia-Pacific region and identified factors associated with adverse psychological outcomes.
From 29 April to 4 June 2020, the study recruited healthcare workers from major healthcare institutions in five countries in the Asia-Pacific region. A self-administrated survey that collected information on prior medical conditions, presence of symptoms, and scores on the Depression Anxiety Stress Scales and the Impact of Events Scale-Revised were used. The prevalence of depression, anxiety, stress and post-traumatic stress disorder (PTSD) relating to COVID-19 was compared, and multivariable logistic regression identified independent factors associated with adverse psychological outcomes within each country.
A total of 1146 participants from India, Indonesia, Singapore, Malaysia and Vietnam were studied. Despite having the lowest volume of cases, Vietnam displayed the highest prevalence of PTSD. In contrast, Singapore reported the highest case volume, but had a lower prevalence of depression and anxiety. In the multivariable analysis, we found that non-medically trained personnel, the presence of physical symptoms and presence of prior medical conditions were independent predictors across the participating countries.
This study highlights that the varied prevalence of psychological adversity among healthcare workers is independent of the burden of COVID-19 cases within each country. Early psychological interventions may be beneficial for the vulnerable groups of healthcare workers with presence of physical symptoms, prior medical conditions and those who are not medically trained.
This article addresses recent advances in liquid phase transmission electron microscopy (LPTEM) for studying nanoscale synthetic processes of carbon-based materials that are independent of the electron beam—those driven by nonradiolytic chemical or thermal reactions. In particular, we focus on chemical/physical formations and the assembly of nanostructures composed of organic monomers/polymers, peptides/DNA, and biominerals. The synthesis of carbon-based nanomaterials generally only occurs at specific conditions, which cannot be mimicked by aqueous solution radiolysis. Carbon-based structures themselves are also acutely sensitive to the damaging effects of the irradiating beam, which make studying their synthesis using LPTEM a unique challenge that is possible when beam effects can be quantified and mitigated. With new direct sensing, high frame-rate cameras, and advances in liquid cell holder designs, combined with a growing understanding of irradiation effects and proper experimental controls, microscopists have been able to make strides in observing traditionally problematic carbon-based materials under conditions where synthesis can be controlled, and imaged free from beam effects, or with beam effects quantified and accounted for. These materials systems and LPTEM experimental techniques are discussed, focusing on nonradiolytic chemical and physical transformations relevant to materials synthesis.
The availability of large healthcare datasets offers the opportunity for researchers to navigate the traditional clinical and translational science research stages in a nonlinear manner. In particular, data scientists can harness the power of large healthcare datasets to bridge from preclinical discoveries (T0) directly to assessing population-level health impact (T4). A successful bridge from T0 to T4 does not bypass the other stages entirely; rather, effective team science makes a direct progression from T0 to T4 impactful by incorporating the perspectives of researchers from every stage of the clinical and translational science research spectrum. In this exemplar, we demonstrate how effective team science overcame challenges and, ultimately, ensured success when a diverse team of researchers worked together, using healthcare big data to test population-level substance use disorder (SUD) hypotheses generated from preclinical rodent studies. This project, called Advancing Substance use disorder Knowledge using Big Data (ASK Big Data), highlights the critical roles that data science expertise and effective team science play in quickly translating preclinical research into public health impact.
Developing alternatives to antibiotics is an urgent need in livestock production. Antimicrobial peptides (AMPs) are regarded as powerful antibiotic substitutes (ASs) because AMPs have broad-spectrum antimicrobial activities and growth-promoting ability. Here, we aimed to comprehensively assess the effects of AMPs on the growth performance, diarrhea rate, intestinal morphology and immunity of healthy or challenged piglets, compared with an antibiotics group or negative control group. We performed a set of meta-analyses of feeding trials from database inception to 27 May 2019. Among the 1379 identified studies, 20 were included in our meta-analyses (56 arms and 4067 piglets). The meta-analyses revealed that (1) compared with the negative control group, AMPs significantly improved the healthy piglets’ average daily gain (ADG), average daily feed intake (ADFI), gain : feed ratio (G/F), levels of immune globulin (Ig) IgM and IgG, and intestinal villus height : crypt depth ratio (V/C) (P < 0.05). Meanwhile, AMPs significantly increased the challenged piglets’ ADG, ADFI, G/F and V/C of the jejunum and ileum, and notably deceased the diarrhea rate (P < 0.05); (2) compared with antibiotics group, the effects of AMPs were slightly weaker than those of antibiotics in the healthy piglets, but AMPs have similar effects to those of antibiotics in challenged piglets. In a higher purity, the optimal dose of AMPs may be approximately 0.01%. Our findings indicate that AMPs can improve piglet growth performance, enhance immunity, benefit intestinal morphology and decrease the diarrheal rate. AMPs could be great ASs especially under infection conditions.
Available data suggest that sex hormone levels during puberty may affect symptom onset and expression, treatment responsiveness and outcomes in schizophrenia, whereas post-pubertal adolescents may have a similar clinical presentation and treatment response compared to adults with schizophrenia.
Post-hoc analyses were conducted to assess the similarity of short- and long-term efficacy between post-pubertal adolescents and adults with schizophrenia treated with aripiprazole.
Based on available European epidemiologic data, a cut-off age of 15 years was used to isolate a subgroup of mostly post-pubertal adolescents with schizophrenia in aripiprazole clinical studies. Outcome measures from this subgroup (ages 15-17; n=147) were then compared to outcomes from one adult study (n=853) on short and long-term measures of efficacy, including PANSS scores, response rates, and remission rates.
Comparable short and long-term treatment effects were observed on the PANSS total and subscale scores, demonstrated by overlapping 95% confidence intervals (mean change from baseline in PANSS total score (OC dataset): at week 6 in adults: -27,7; in adolescents 15-17 yr: -29,6; at week 30 in adults: -39,2; in adolescents 15-17 yr: -36). Percent of adolescents achieving response (defined as ≥ 30% decrease in PANSS total score from baseline) at 32 weeks (80,2%) on open label treatment was similar to that in adult studies at week 34 (80%) on double blind treatment (OC dataset).
Adolescents with schizophrenia (ages 15-17, mostly post-pubertal) demonstrate a positive treatment response in short-term and long-term studies which is similar to that observed in the adult patient population.
Previous studies have shown that African American youth are over-represented in the Criminal Justice System (CJS). Substance use problems are common among those with CJS involvement. However, less is known regarding racial disparities, among youth with CJS involvement, in receiving substance use treatment services.
To examine racial disparities with regard to receiving treatment services for substance use related problems, among youth with (CJS) involvement.
Data were obtained from the 2006–2008 United States National Survey on Drug Use and Health (NSDUH) in USA. Among White and African American adolescents (Ages 12–17) with recent CJS involvement and who met criteria for alcohol or illicit drug abuse or dependence (N = 602), racial differences in receiving treatment services for substance use problems were examined. Multiple logistic regression analyses were performed to identify predictors of service access among the adolescents, to see if the racial disparity could be explained by individual-level, family-level, and criminal justice system involvement factors.
While 31.2% of White adolescent substance abusers with CJS involvement had received treatment for substance use related problems, only 11.6% of their African American counterparts had received such treatment (P = 0.0005). Multiple logistic regression analyses showed that access to treatment services can be predicted by substance use related delinquent behaviors, but that racial disparities in treatment still exist after adjusting for these factors (AOR = 0.24, 95%CI = (0.09,0.59), P = 0.0027).
There is an urgent need to reduce racial disparities in receiving substance use treatment among U.S. youth with CJS involvement.
Optimal stroke care requires access to resources such as neuroimaging, acute revascularization, rehabilitation, and stroke prevention services, which may not be available in rural areas. We aimed to determine geographic access to stroke care for residents of rural communities in the province of Ontario, Canada.
We used the Ontario Road Network File database linked with the 2016 Ontario Acute Stroke Care Resource Inventory to estimate the proportion of people in rural communities, defined as those with a population size <10,000, who were within 30, 60, and 240 minutes of travel time by car from stroke care services, including brain imaging, thrombolysis treatment centers, stroke units, stroke prevention clinics, inpatient rehabilitation facilities, and endovascular treatment centers.
Of the 1,496,262 people residing in rural communities, the majority resided within 60 minutes of driving time to a center with computed tomography (85%), thrombolysis (81%), a stroke unit (68%), a stroke prevention clinic (74%), or inpatient rehabilitation (77.0%), but a much lower proportion (32%) were within 60 minutes of driving time to a center capable of providing endovascular thrombectomy (EVT).
Most rural Ontario residents have appropriate geographic access to stroke services, with the exception of EVT. This information may be useful for jurisdictions seeking to optimize the regional organization of stroke care services.
Early-type galaxies (ETGs) are of crucial importance to trace back the galaxy mass assembly across cosmic time, yet their formation and quenching remain remarkably elusive. The discoveries of massive, dead galaxies at ever-growing redshifts provided compelling evidence to push their formation up to redshift > 4–5 when the Universe was barely 1 Gyr old. In this talk I will present our results on the ages of a new sample of ETGs at z ∼ 3, built by exploiting HST WFC3/G141 rest-frame optical/near-UV grism spectroscopy to study the nature of 10 passive galaxy candidates at 2.5 < z < 3.5 in COSMOS.
This work is part of a PhD project aimed at quantifying the parent space density of distant genuine passive galaxies. I will also discuss the importance of multi-wavelength data in clarifying the degree of contamination by dusty star-forming galaxies affecting the color selection.
To examine the associations between overall diet quality and hearing function among middle–older aged adults in the USA.
Cross-sectional analysis. Diet quality was examined using the Mediterranean Diet Score (MDS), using data from a single 24 h dietary recall. Hearing function was objectively measured by audiometry assessments and hearing loss, including high- and low-frequency hearing loss, was defined as pure-tone averages at specific ranges of hearing frequencies >25 dB. Weighted logistic regression analyses were performed to examine the associations of MDS (scored 0–9, categorized at the median as ≤3 or >3) with hearing loss and high- and low-frequency hearing loss.
National Health and Nutrition Examination Surveys 2000–2006 and 2009–2012.
Adults aged ≥50 years (n 1639) with valid dietary and audiometry assessments.
After adjusting for potential confounders, a non-significant trend for a protective association of higher MDS was observed for hearing loss (OR = 0·78; 95 % CI 0·49, 1·23). A significant inverse association was observed for high-frequency hearing loss (OR = 0·64; 95 % CI 0·43, 0·95). No association was found for low-frequency hearing loss among women; however, higher MDS was significantly associated with higher odds of low-frequency hearing loss among men (OR = 2·63; 95 % CI 1·39, 4·95).
Among middle–older aged adults, adherence to a Mediterranean-style diet was inversely associated with hearing loss, including those at high hearing frequencies, among older adults. However, a detrimental association was observed at low hearing frequencies among men. Future investigations with a longitudinal design are needed to clarify the associations between diet quality and hearing loss.
The search for life in the Universe is a fundamental problem of astrobiology and modern science. The current progress in the detection of terrestrial-type exoplanets has opened a new avenue in the characterization of exoplanetary atmospheres and in the search for biosignatures of life with the upcoming ground-based and space missions. To specify the conditions favourable for the origin, development and sustainment of life as we know it in other worlds, we need to understand the nature of global (astrospheric), and local (atmospheric and surface) environments of exoplanets in the habitable zones (HZs) around G-K-M dwarf stars including our young Sun. Global environment is formed by propagated disturbances from the planet-hosting stars in the form of stellar flares, coronal mass ejections, energetic particles and winds collectively known as astrospheric space weather. Its characterization will help in understanding how an exoplanetary ecosystem interacts with its host star, as well as in the specification of the physical, chemical and biochemical conditions that can create favourable and/or detrimental conditions for planetary climate and habitability along with evolution of planetary internal dynamics over geological timescales. A key linkage of (astro)physical, chemical and geological processes can only be understood in the framework of interdisciplinary studies with the incorporation of progress in heliophysics, astrophysics, planetary and Earth sciences. The assessment of the impacts of host stars on the climate and habitability of terrestrial (exo)planets will significantly expand the current definition of the HZ to the biogenic zone and provide new observational strategies for searching for signatures of life. The major goal of this paper is to describe and discuss the current status and recent progress in this interdisciplinary field in light of presentations and discussions during the NASA Nexus for Exoplanetary System Science funded workshop ‘Exoplanetary Space Weather, Climate and Habitability’ and to provide a new roadmap for the future development of the emerging field of exoplanetary science and astrobiology.
For decades, fructose intake has been recognised as an environmental risk for metabolic syndromes and diseases. Here we comprehensively examined the effects of fructose intake on mice liver transcriptomes. Fructose-supplemented water (34 %; w/v) was fed to both male and female C57BL/6N mice at their free will for 6 weeks, followed by hepatic transcriptomics analysis. Based on our criteria, differentially expressed genes (DEG) were selected and subjected to further computational analyses to predict key pathways and upstream regulator(s). Subsequently, predicted genes and pathways from the transcriptomics dataset were validated via quantitative RT-PCR analyses. As a result, we identified eighty-nine down-regulated and eighty-eight up-regulated mRNA in fructose-fed mice livers. These DEG were subjected to bioinformatics analysis tools in which DEG were mainly enriched in xenobiotic metabolic processes; further, in the Ingenuity Pathway Analysis software, it was suggested that the aryl hydrocarbon receptor (AhR) is an upstream regulator governing overall changes, while fructose suppresses the AhR signalling pathway. In our quantitative RT-PCR validation, we confirmed that fructose suppressed AhR signalling through modulating expressions of transcription factor (AhR nuclear translocator; Arnt) and upstream regulators (Ncor2, and Rb1). Altogether, we demonstrated that ad libitum fructose intake suppresses the canonical AhR signalling pathway in C57BL/6N mice liver. Based on our current observations, further studies are warranted, especially with regard to the effects of co-exposure to fructose on (1) other types of carcinogens and (2) inflammation-inducing agents (or even diets such as a high-fat diet), to find implications of fructose-induced AhR suppression.