Effects of antibiotics on microbial nitrogen transformation processes in natural aquatic ecosystems are largely unknown. In this study, we utilized the N-15 stable isotope tracers and metagenomic sequencing to identify how antibiotics drive nitrogen transformation processes in Danjiangkou Reservoir, which is the largest artificial drinking water reservoir in China. We retrieved 51 nitrogen functional genes, and found that the highest abundances of nitrate reduction and denitrification-related genes occurred in dissimilatory nitrogen transformation pathways. N-15-labelling analysis substantiated that denitrification was the main pathway for nitrogen removal, accounting for 57.1% of nitrogen loss. Nitrogen functional genes and antibiotic resistance genes co-occurred in Danjiangkou Reservoir, and they were mainly carried by the denitrifying bacteria such as Rhodoferax, Polaromonas, Limnohabitans, Pararheinheimera, Desulfobulbus, and Pseudopelobacter. Genome annotation revealed that antibiotic deactivation, Resistance-Nodulation-Division and facilitator superfamily efflux pumps were responsible for the multiple-resistance to antibiotics in these bacteria. Moreover, antibiotics showed non-significant effects on nitrogen transformation processes. It is speculated that denitrifying bacteria harboring ARGs played crucial roles in protecting nitrogen transformation from low-level antibiotics stress in the reservoir. Our results highlight that denitrifying bacteria are important hosts of ARGs, which provides a novel perspective for evaluating the effects of antibiotics on nitrogen cycle in natural aquatic ecosystems. (C) 2021 Elsevier B.V. All rights reserved.
In recent years, the scale of international students in China is growing rapidly, but the quality of education for international students in China seems to be obviously lagging behind, which is reflected in the academic level. These disadvantages and deficiencies have seriously hindered the development of the education of foreign students in China. To improve the quality of international students in China, colleges and universities must carry out curriculum reform and strengthen the construction of teachers. The government and society must also play their respective roles in formulating long-term policies. It is expected to have a clear international education development strategy, establish the quality standards of education and teaching for international students in China, and establish the trinity of government, society and universities. Thus, the educational quality assurance system must be established to realize effective monitoring.
Micro-nanofluidic technology is widely used in food safety testing, drug screening, new material synthesis and bioengineering. Droplet microfluidic technology is an important branch of micro-nanofluidic technology. The microdroplet technology can produce high-throughput monodisperse droplets. The droplet technology overcomes many problems of continuous flow, such as small sample reagent volume, no cross-contamination, and rapid chemical reaction. So microdroplets have an important position in the fields of single cell analysis, gene sequencing, and real-time diagnosis. This review focuses on the different methods and applications of microdroplet generation in microfluidics. The droplet generation methods are passive and active methods. The passive method does not require external force, while the active method requires external force such as external electric field, magnetic field, acoustic field, and laser field. It is predicted that the quantitative generation of droplets on demand in microfluidics will be the important direction for future research. This review provides new ideas for the applications of the quantitative generation of microdroplets on demand in microfluidics.
This edited volume started as a conference panel on marriage discourses in Hellenistic and imperial literature sponsored by the International Plutarch Society for the 2013 SCS conference. However, a new aspiration emerged as the panel discussion highlighted the importance of attaining an in-depth appreciation of “how the discourse of marriage, as found in the different genres that might have been important to Plutarch or related to his writings – philosophy, art, epithalamium, epic, and the novel – developed over time” (p. 4). This is an ambitious assemblage of source materials and perspectives that would generally be treated in separate monographs. As examples, Tsouvala points to Larsson Lovén and Agneta Stömberg’s Ancient Marriage in Myth and Reality (2010), Claude-Emmanuelle Centlivres Challet’s Like Man, Like Woman: Roman Women, Gender Qualities and Conjugal Relationships at the Turn of the First Century (2013), and Nikoletta Manioti’s Family in Flavian Epic (2016). The first paper by Rebecca H. Sinos explores parallels between wedding rites and mystery rites in the pictorial tradition. Sinos uses a small assemblage of vases to demonstrate the Attic pictorial tradition for weddings, then focuses on two fourth-century relief vases recently re-published in Zimmermann-Elseify’s Corpus Vasorum Antiquorum volume (2015)[1] that depict scenes set within the bridal chamber (thalamos), yielding rare “insight into the bridal couple’s experience of the wedding” (p. 33). The first is a relief vase in Moscow (but once part of the Berlin collection) initially published in Brückner’s Anakalypteria, showing the bride in a veil and being comforted by another woman at the end of a couch on which the bridegroom is reclining. The second is a relief vase in the Berlin Staatliche Museen that shows the bride unveiling herself to the reclining bridegroom on the bridal couch. Along with other examples, Sinos provides a nice presentation on the preparatory journey from betrothal, to procession, to the final unveiling of the bride within the bridal chamber, and how their association with divinizing or heroizing sculpture reliefs, including depictions of funerary banquets and those with Eleusinian allusions, can be read as conflating wedding rites and mystery rites. Karen Klaiber Hersch reads the Roman wedding as a ritualization of violence that the Roman bride suffers. Antiquarian sources such as Festus (55L; 43L) and Plutarch (Quaest. Rom. 87, 285C) lead Hersch to believe that “every Roman wedding…was a reenactment of a forced mass marriage of maidens from neighboring communities to the male population of Rome” (p. 70). She says that brides were expected “to appear to be terrified and were expected to make a vocal (and insofar as possible, visual) display of sorrow” to demonstrate virginity (p. 74-75). The bride’s veil (flammeum) functionally forces her “to mime her sorrow by hanging her head dejectedly, or walking with timid, uncertain steps, or even by crying audibly” (p. 76). Plautus (Casina922-31; Priapea 3.8-9) and Macrobius (Sat. 1.15.21-22) further lead Hersch to believe that the literary descriptions of the suffering bride were likely based on actual verbal and physical assaults intended “to make the transition to matronhood as painful as possible” (pp. 84-85). Strikingly, Hersch points out that Greek rites were known to invoke marital happiness and positive experiences of marriage, establishing a provocative contrast of cultural norms and experiences that may benefit from further exploration. Paolo Di Meo’s chapter deals with the genesis and the nature of Plutarch’s Marriage Advice in the context of the epithalamium tradition. Passages from Claudian (Fescennines for Honorius 14.2-11, 14.16-24 and the Epithalamium of Palladius and Celerina (25.130-38) are used to demonstrate the common stock of motifs (such as plants with thorns and bee-guarded honey) that would encourage the bridegroom to carry on despite the bride’s refusals, and encourage the bride to collaborate. Deities invoked in the prologue are also explicitly linked to poets such as Statius (Silv. 1.2.3-6, 11-21) and Catullus (61.101-109), apparently in the Sapphic epithalamic tradition. Di Meo concluded that, while Plutarch followed models of wedding speeches in rhetoric, he reused the poetic epithalamium to diverge from “the utilitarian conception and the cold analyses of marriage” (pp. 110-111), purposely creating a practical but warm and passionate wedding gift for a couple. Plutarch specifically quotes the Sapphic fragment 55 in the epilogue, which is thus a natural candidate for Plutarch’s archetype, and Di Meo convincingly supports this connection with a survey of various Sapphic adherents and epideictic variations, highlighting lexical and figurative associations within the centuries-old epithalamic motifs in the prologue and the four precepts. Geert Roskam’s project is to come to a determination on Epicurus’ position on marriage and children. While many reports suggest that Epicurus rejected marriage and children, Roskam argues that Epicurus’ position was more nuanced than the reports of his views on marriage suggest. Roskam’s key text is a short passage from Diogenes Laertius that reports Epicurus saying in the Diaporiaiand On Nature that the sage will both marry and rear children, and will sometimes marry according to his circumstances in life (Diog. Laert. 10.119). Since Epicurus emphasized the importance of prudence (φρόνησις) when dealing with dilemmas such as “whether the sage will break the law if he can be sure that he will never be detected” (Plut. Adv. Col. 1127D) and “whether an old and impotent sage still derives pleasure from touching the fair” (Plut. Non posse 1094E), and since Epicurus is known to have discussed marriage in theDiaporiai, “he probably recognized that, under particular circumstances, marriage may well yield more pleasure than pain” (pp. 126-128). Roskam pointed to “the concrete praxis of the Epicureans themselves” that reveals Epicurus’ actual position, and Epicurus’ testamentary arrangements for his heirs to take care of the sons and the daughter of Metrodorus also suggest that Epicurus’ position was that “specific περίστασις βίου [can] occasionally persuade the Epicurean philosopher to marry” (p. 136). One wonders whether more examples of Epicurean praxis could be gleaned from elsewhere to escape the heavy reliance on Diogenes Laertius’ reports. Alex Dressler focuses on the witty quips of virtuous wives in Seneca’s On Marriage reported by Jerome in the treatise Against Jovinian, and considers whether such remarks were criticisms “from the perspective of real women” against ancient Roman marriage as it was practiced in Rome (p. 145). If they are, then it would be “completed” feminism, an active practice of the destruction of the institution of marriage through women’s agency (p. 161). While Marcia’s clever representation of Roman marriage (Jer. Adv. Iovinian. 1.46, 275c) embodies a woman’s self-assertion and elegant lifestyle choice, it does not consitute “completed feminism,” because in Seneca-in-Jerome such a notion remains only a possibility: women can be satirists or violent revolutionaries, “but they cannot be both” (p. 161). Dressler had to use some of Seneca’s more complete works such as the Consolation to Marcia and epistolary writings (e.g. Sen. Ep. 7.10-11) and add some modern filters, such as the mimesis e contrariotaken from Torre’s Il matrimonio del Sapiens (2000); the conclusion that Seneca-in-Jerome created a space for women “to imagine freedom and equality, even if they prefer death” (p. 164) is quite convincing. Katarzyna Jazdzewska examines three of Plutarch’s treatises that use animal stories to discuss marriage and marital virtues – On the Love of Offspring, On the Fact that Beasts are Rational, and On the Intelligence of Animals. The question asked, implicitly, is how anthropomorphized and moralized animals and their mating behaviors help Plutarch convey his perceptions of marriage, and how such perceptions differ from Plutarch’s other works. Jazdzewska identified two sets of perceptions on marriage conveyed using animal stories: the first emphasizes procreative function and the subordinate relationship female to male between mates, while the other is the mates’ love and care for each other. She then searches for similarities in Plutarch’s Marriage Advice and Dialogue on Love, showing that Plutarch deliberately chose a range of animal paradigms paraenetically – such as uxorial devotedness among female kingfishers from On the Intelligence of Animals (De sol. an. 982 E-983 B) and chaste female crows (Brut. Anim. 989A-B) – to demonstrate the universality of parental affection among animals. To Jazdzewska, Plutarch’s aim is to convince the reader “that it would be shameful if people were to be found inferior to animals in respect to parental love” (p. 189). The study is limited in scope, as it only deals with Plutarch’s works, but nevertheless throws light on Plutarch’s communication strategy. Jeffrey Beneker’s chapter asks how Plutarch structures the virtue of moderation (sophrosyne) with the moral example of Camma the Galatian woman in the Dialogue on Love (767C-768D) and in Virtues of Women (257E-258 C). Camma – because she was both sophron and erotically attached to her husband – was not only able to remain faithful even after her suitor Sinorix killed her husband Sinatus, but also capable of avenging her husband by suicide, tricking Sinorix into drinking poison with her from a shared cup. Beneker argues that Camma’s story influenced Plutarch’s depiction of Porcia, Brutus’s wife, perhaps with Panthea in Xenophon’s Cyropaedia in the deep background (Xen. Cyr. 6.4.5-6.4.9). Beneker then shifts to focus on Cornelia, the mother of the Gracchi in the Lives (Gracch.1.4-1.7), observing that the same model of the sophron and devoted wife was used to cast her in the character of the paradigmatic Roman wife. Beneker argues that Porcia and Cornelia were placed in such a model because they were meant to “stand alongside the great men of the Parallel Lives” as idealized individuals “whose characters might be imitated even if their accomplishments could not be matched” (p. 214). This chapter seems to speak to Dressler’s, as both deal with male-generated paradigms of women, while using different strategies of paradigmatization. Silvia Montiglio’s paper covers “the interplay between eros and the call to institutionalize it” in two sets of imperial period Greek novels, the first including Chariton’s Chaereas and Callirhoe and Xenophon of Ephesus’ An Ephesian Tale, while the second comprises Achilles Tatius’Leucippe and Clitophon, Longus’ Daphnis and Chloe, and Heliodorus’ An Ethiopian Story. The sortition is based on whether marriage happens before an adventure or at the end of it – a narratological manipulation (for ideological and educational purposes), creating uncertainty as to the protagonists’ faith in each other. As Montiglio moves from one novel to the other, we find that the first group’s marriage union was “required by society and the novelistic genre” (p. 223). In contrast, the second group emphasizes the notion of consent, which Montiglio suggests is in line with the historical evolution of postclassical ideals and laws. Montiglio concluded that, in Greek novels, “marriage is not a natural bond, and no novelist pretends it is,” and various figurative and narratological strategies were necessary to navigate the naturalness of erotic longing and the artificiality of marriage. Given that the five novels were sorted narratologically, much space is used to unfold at least the skeleton plot of each. As a result, the analytical aspect of the contribution could perhaps be further expanded in a separate paper. The revised scope of the edited volume has brought a considerable number of perspectives that tap into a similar pool of traditions and genres, and it is useful to return to Tsouvala’s introduction, where some of the common themes and diachronic changes are highlighted to make the volume more coherent. Interestingly, Montiglio’s paragraph on the historical evolution of marriage points to possible supplements to the volume: how does marriage discourse change with changing historical circumstances of marriage? Tsouvala devotes a section of the introduction to covering some aspects of this question, but rather briefly. If there is anything lacking in this enjoyable volume, perhaps it would be a closer and dedicated discussion of the evolution of the discourse on marriage in the Greco-Roman world. Authors and Titles1. Introduction, the Discourse of Marriage and Its Context, Georgia Tsouvala2. Wedding Connections in Greek and Roman Art, Rebecca H. Sinos3. Violence in the Roman Wedding, Karen Klaiber Hersch4. Plutarch’s Marriage Advice and the Tradition of the Poetic Epithalamium, Paolo Di Meo5. Epicurus on Marriage, Geert Roskam6. The Impossible Feminism of “Seneca, On Marriage”: Style and the Woman in Jerome, Against Jovinian 1, Alex Dressler7. Marriage and Animal Exemplarity in Plutarch, Katarzyna Jazdzewska8. Death is Not the End: Spousal Devotion in Plutarch’s Portraits of Camma, Porcia, and Cornelia, Jeffrey Beneker9. Erotic Desire and the Desire to Marry in the Ancient Greek Novels, Silvia Montiglio Notes [1] CVA Deutchland: Berlin: Antikensammlung, Band 16: Attische Salbgefässe, bearbeitet von Nina Zimmermann-Elseify. Munich: C. H. Beck Verlag, 2015.
Oxygen is one of the most abundant elements in the universe and ubiquitously participates in geological and biological processes which play a critical role in shaping and maintaining habitability of the Earth. Its isotope composition is a key parameter to decode these geological and biological processes. For example, oxygen isotope composition of biogenic and abiogenic apatite are ideal proxies to reconstruct sea surface temperature and to tackle elemental cycling respectively, in which accurate and precise apatite oxygen isotope analysis is a basic requirement. Our robust evaluation demonstrates a lack of crystallographic orientation effects for Secondary Ion Mass Spectrometry (SIMS) apatite oxygen isotope analysis (expressed as delta O-18). Apatite grains separated from the Qinghu monzonite were extensively analyzed by SIMS in the past decade in our laboratory, and 2041 individual delta O-18 measurements yield a two-standard-deviation of 0.47 parts per thousand (per mil, V-SMOW), or 0.16 parts per thousand when these measurements were integrated into 195 sessions. Homogenous oxygen isotope composition of Qinghu apatite (Qinghu-AP) at the micrometer level makes it a suitable reference material with a recommended delta O-18 value of 5.59 +/- 0.19 parts per thousand, as measured by Gas Source Isotope Ratio Mass Spectrometry with further validation from oxygen isotope thermometry. For seven randomly selected IGG (Institute of Geology and Geophysics)-Durango apatite crystals, our SIMS measurements suggest that they also have homogenous delta O-18 values (9.70 +/- 0.22 parts per thousand, 2 SD, n = 241, using Qinghu-AP as standard) without the presence of inter-grain and intra-grain heterogeneity. We documented a Y-coordinate related artificial effect, with measured delta O-18 values gradually increasing by similar to 1 parts per thousand from bottom to top of the mount over a distance of similar to 1.2 cm. This artifact is most likely caused by the presence of a slope (imperfect sample preparation and loading) or a gradient of accelerating voltage (conductivity of holder and sample) on the sample surface along the Y direction, which leads to an imperfect centering of the trajectory of the secondary ions. This effect can be reduced through applying a DTFA (dynamic transfer field aperture)-X correction. The presence of position-specific oxygen isotope fractionation could cause an artificial bias up to -6.7 parts per thousand when analyzing carbonated hydroxyapatite, and can reconcile the offset (e.g., -0.9 to 3.3 parts per thousand) between delta O-18 values of conodonts measured by SIMS and IRMS. When working on hydrous systems (e.g., ore deposits) and low temperature environment (e.g., conodonts), where apatite is known to be water-rich and could be carbonated, a rigorous evaluation on this artificial bias is warranted. Since position-specific oxygen isotope fractionation is a common phenomenon observed in a variety of minerals (e.g., goethite, tourmaline and muscovite), attention should be paid in future studies. Our study highlights that SIMS is capable of providing accurate and precise delta O-18 measurements at the similar to 0.2 parts per thousand level, but high-quality reference materials and rigorous evaluations of potential artificial effects (e.g., topography, position, matrix, orientation, sample holder and position-specific oxygen isotope fractionation) degrading analytical accuracy are prerequisites.
A ridge-channel AlGaN/GaN high-electron mobility transistor (HEMT) utilizing selective-area growth and epitaxial lateral overgrowth (ELO) technique is proposed in this work to achieve high-performance normally-off devices. It has a c-plane platform for the source and the drain contacts, and sidewalls of lattice plane for the gate contact. The sidewalls have characteristics of weak polarization and thin barrier, which are advantageous for realizing normally-off operation. Two ridge HEMTs with triangular and trapezoid channel are designed. Theoretical simulation demonstrates a threshold voltage of 0.03 V for the sidewall channel with reduced polarization and barrier thickness, and a threshold voltage of 1.1–1.3 V for the ridge HEMTs assuming no polarization charge in sidewall channel. The ridge-channel device also exhibits high saturation drain current. The ELO-based ridge-channel opens a new way to achieve normally-off AlGaN/GaN HEMT.
Abstract As a bridge linking propagating waves and surface waves, reflective metasurfaces (with metal cladding at the bottom) play a significant role in the field of beam steering. The feasibility and flexibility to control electromagnetic waves by reflective metasurfaces depend on the recognition of their physical properties by researchers. As for bianisotropic reflective metasurfaces, however, the effective-medium characteristics cannot be appropriately described by conventional methods, which entail both transmission and reflection coefficients. Here, a robust method based on simplex S-parameters is proposed to retrieve constitutive effective parameters (CEPs) for bianisotropic reflective metasurfaces. By illuminating the transverse electric-polarization plane waves on a split-ring unit cell normally and obliquely, the CEPs can be calculated with only S11 parameters. To demonstrate the effectiveness of the retrieval results, an analysis of small incident angles is employed to examine the consistency of both the x- and y-directions effective impedance and determine the accurate range of the incident angles. Moreover, the sensitivity of the retrieval results to S-parameters is also sufficiently discussed. This method is beneficial for the applications of one-side complex materials, e.g., dual-function reflective metasurfaces, multichannel reflectors, excitation of spoof space plasmon polaritons, and ground-penetrating-radar applications.
In contrast to agricultural settings, the process of urbanization in the pastoral regions of China are largely driven by long-term influences of ecological conservation and the provision of social services. Consequently, many of the herders who have migrated into nearby secondary urban centers depend on resources from pastoral regions to support their livelihoods, forming complex patterns of rural–urban linkages. While current literature has discussed the processes of herder out-migration and their implications on rural and urban livelihood development, few studies have examined the linkages between the herders living in the pastoral regions and those who have out-migrated to urban regions and their importance in rural livelihood transformation. Based on past studies, we argue that, in a changing pastoral social–ecological system, herders living in both rural and urban regions depend on each other to support their livelihoods through three types of mobility: (1) livestock mobility, (2) herder mobility, and (3) resource mobility. However, what innovative institutions in rangeland resource management and herder economic cooperation can do to help maintain these three types of mobility to sustain rural livelihood development, becomes a critical challenge. Innovative community cooperative institutions developed by pastoral communities from the Tibetan Plateau and Inner Mongolia may be able to offer new perspective and insight on how to better maintain rural–urban linkages in the processes of urbanization in pastoral regions. In this current study will present the two cases of innovative institutions and the roles they play in facilitating the three types of mobility to address livelihood challenges. While current studies recommend an increase of government subsidies, provision of vocational training, and social insurance that help herders better adapt to urban livelihood, we argue that rangeland management and community economic cooperation in innovative institutions are needed to facilitate the mobility of livestock, resources, and the herder population, and maybe only then the livelihood challenges that migrated herders are facing will be addressed effectively.
Interpreting subjectivity in causal relations takes effort: Subjective, claim-argument relations are read slower than objective, cause-consequence relations. In an eye-tracking-while-reading experiment, we investigated whether connectives and stance markers can play a facilitative role. Sixty-five Chinese participants read sentences expressing a subjective causal relation, systematically varied in the use of stance markers (no, attitudinal, epistemic) in the first clause and connectives (neutral suoyi “so”, subjective kejian “so”) in the second clause. Results showed that processing subjectivity proceeds highly incrementally: The interplay of the subjectivity markers is visible as the sentence unfolds. Subjective connectives increased reading times, irrespective of the type of stance marker being used. Stance markers did, however, facilitate the processing of modal verbs in subjective relations. We conclude that processing subjectivity involves evaluating how the argument supports the claim and that connectives, modal verbs, and stance markers function as processing instructions that help readers achieve this evaluation.
Artificial neural networks (ANNs), like convolutional neural networks (CNNs), have achieved the state-of-the-art results formanymachine learning tasks. However, inference with large-scale full-precision CNNs must cause substantial energy consumption and memory occupation, which seriously hinders their deployment on mobile and embeddedsystems. Highly inspired from biological brain, spiking neural networks (SNNs) are emerging as new solutions because of natural superiority in brain-like learning and great energy efficiency with event-driven communication and computation. Nevertheless, training a deep SNN remains a main challenge and there is usually a big accuracy gap between ANNs and SNNs. In this paper, we introduce a hardware-friendly conversion algorithm called “scatter-and-gather” to convert quantized ANNs to lossless SNNs, where neurons are connected with ternary {−1,0,1} synaptic weights. Each spiking neuron is stateless and more like original McCulloch and Pitts model, because it fires at most one spike and need be reset at each time step. Furthermore, we develop an incremental mapping framework to demonstrate efficient network deployments on a reconfigurable neuromorphic chip. Experimental results show our spiking LeNet on MNIST and VGG-Net on CIFAR-10 datasetobtain 99.37% and 91.91% classification accuracy, respectively. Besides, the presented mapping algorithm manages network deployment on our neuromorphic chip with maximum resource efficiency and excellent flexibility. Our four-spike LeNet and VGG-Net on chip can achieve respective real-time inference speed of 0.38 ms/image, 3.24 ms/image, and an average power consumption of 0.28 mJ/image and 2.3 mJ/image at 0.9 V, 252 MHz, which is nearly two orders of magnitude more efficient than traditional GPUs.