Explore the vast range of titles available.

Nearly every piece of research on the phonology of Mixtec languages makes reference to the couplet, a term used to describe the shape of canonical roots and to explain the domain of numerous phonological processes. Despite its ubiquity, scholars disagree over whether the couplet should be defined in prosodic terms as a bimoraic foot, or in morphological terms as a root. In this paper, we describe and analyze three patterns in San Martín Peras Mixtec that are commonly attributed to the couplet in the Mixtec literature, namely the distribution of laryngeals, tones, and nasality. We show that, in San Martín Peras Mixtec, the foot is necessary to explain the distribution of laryngeals and rising tones, while the root is needed to explain the domain of phonotactic restrictions on nasality. We conclude that the Mixtec couplet does not correspond to a single grammatical category across all varieties, and that the couplet in San Martín Peras Mixtec is an emergent category that arises out of the interaction of (at least) the bimoraic foot and the morphological root.

The present study reveals the changes in the characteristics of cold surges over East Asia associated with the Arctic Oscillation (AO). Based on circulation features, cold surges are grouped into two general types: wave train and blocking types. The blocking type of cold surge tends to occur during negative AO periods, that is, the AO-related polarity of the blocking type. However, the wave train type is observed during both positive and negative AO periods, although the wave train features associated with negative AO are relatively weaker. The cold surges during negative AO are stronger than those during positive AO in terms of both amplitude and duration. The cold surges during positive AO in which the extent of effect is confined to inland China passes through East Asia quickly because of weaker Siberian high and Aleutian low, leading to short duration of these cold surges. In contrast, the cold surge during negative AO, characterized by a well-organized anticyclone–cyclone couplet with high pressure over continental East Asia and low pressure over Japan, brings continuous cold air into the entire East Asian region for more than one week with long-lasting cold advection. It is also found that the tracks of the cold surges during negative AO tend to occur more frequently over Korea and Japan and less frequently over China, compared with those during positive AO. The tracks are related to a west–east dipole structure of the ratio of rain conversion to snow according to AO phase, resulting in freezing precipitation or snowfall events over inland China (Korea and Japan) are likely to occur more frequently during the positive (negative) AO periods.

Importance Parent‐infant closeness and active parent participation in neonatal care are important for parent and infant health. Objective To give an overview of current neonatal settings and gain an in‐depth understanding of facilitators and barriers to parent‐infant closeness, zero‐separation, in 19 countries. Methods Neonatal intensive care unit (NICU) professionals, representing 45 NICUs from a range of geographic regions in Europe and Canada, were purposefully selected and interviewed June–December 2018. Thematic analysis was conducted to identify, analyze and report patterns (themes) for parent‐infant closeness across the entire series of interviews. Results Parent‐infant separation during infant and/or maternity care is very common (42/45 units, 93%), despite the implementation of family integrated care (FICare) practices, including parent participation in medical rounds (17/45, 38%), structured education sessions for parents (16/45, 36%) and structured training for healthcare professionals (22/45, 49%). NICU professionals encountered four main themes with facilitators and barriers for parent‐infant closeness on and between the hospital, unit, staff, and family level: Culture (jointly held characteristics, values, thinking and behaviors about parental presence and participation in the unit), Collaboration (the act of working together between and within different levels), Capacities (resources and policies), and Coaching (education to acquire and transfer knowledge and skills). Interpretation Implementing parent‐infant closeness in the NICU is still challenging for healthcare professionals. Further optimization in neonatal care towards zero‐separation and parent‐infant closeness can be achieved by enforcing the ‘four Cs for Closeness’: Culture, Collaboration, Capacities, and Coaching. Implementing parent‐infant closeness in the neonatal intensive care unit is still challenging for healthcare professionals. Further optimization in neonatal care towards zero‐separation and parent‐infant closeness can be achieved by enforcing the ‘four Cs for Closeness’: Culture, Collaboration, Capacities, and Coaching.

Liposomes have been widely used for targeted drug delivery, but the disadvantages caused by cholesterol limit the application of conventional liposomes in cancer treatment. The compatibility basis of couplet medicines and the compatibility principle of the traditional Chinese medicine principle of 'monarch, minister, assistant and guide' are the important theoretical basis of Chinese medicine in the treatment of tumor and the important method to solve the problem of high toxicity. In this study, the active ingredients of the couplet medicines Platycodon grandiflorum and Glycyrrhiza uralensis were innovatively utilized, and glycyrrhizic acid (GA) was encapsulated in liposomes constructed by mixing saponin and lecithin, and cholesterol was replaced by platycodin and ginsenoside to construct saponin liposomes (RP-lipo) for the drug delivery system of Chinese medicine. Compared with conventional liposomes, PR-lipo@GA has no significant difference in morphological characteristics and drug release behavior, and also shows stronger targeting of lung cancer cells and anti-tumor ability in vitro, which may be related to the pharmacological properties of saponins themselves. Thus, PR-lipo@GA not only innovatively challenges the status of cholesterol as a liposome component, but also provides another innovative potential system with multiple functions for the clinical application of TCM couplet medicines.

The Paleocene/Eocene thermal maximum (PETM) and associated carbon isotope excursion (CIE) are often touted as the best geologic analog for the current anthropogenic rise in pCO ₂. However, a causal mechanism for the PETM CIE remains unidentified because of large uncertainties in the duration of the CIE’s onset. Here, we report on a sequence of rhythmic sedimentary couplets comprising the Paleocene/Eocene Marlboro Clay (Salisbury Embayment). These couplets have corresponding δ ¹⁸O cycles that imply a climatic origin. Seasonal insolation is the only regular climate cycle that can plausibly account for δ ¹⁸O amplitudes and layer counts. High-resolution stable isotope records show 3.5‰ δ ¹³C decrease over 13 couplets defining the CIE onset, which requires a large, instantaneous release of ¹³C-depleted carbon. During the CIE, a clear δ ¹³C gradient developed on the shelf with the largest excursions in shallowest waters, indicating atmospheric δ ¹³C decreased by ∼20‰. Our observations and revised release rate are consistent with an atmospheric perturbation of 3,000-gigatons of carbon (GtC).

The role of zonal moisture asymmetry in the eastward propagation of the Madden–Julian oscillation (MJO) is investigated through a set of aquaplanet atmospheric general circulation model (AGCM) experiments with a zonally symmetric sea surface temperature distribution. In the control experiment, the model produces eastward-propagating MJO-like perturbations with a dominant period of 30–90 days. The model MJO exhibits a clear zonal asymmetry in the lower-tropospheric specific humidity field, with a positive (negative) anomaly appearing to the east (west) of the MJO convection. A diagnosis of the lower-tropospheric moisture budget indicates that the asymmetry primarily arises from vertical moisture advection associated with boundary layer convergence, while horizontal moisture advection has the opposite effect. In a sensitivity experiment, the lower-tropospheric specific humidity field is relaxed toward a zonal-mean basic state derived from the control simulation. In this case, the model’s mean state remains the same, but its intraseasonal mode becomes quasi-stationary. The numerical model experiments clearly demonstrate the importance of the zonal moisture asymmetry in MJO eastward propagation.

Oceanic red beds (ORBs) are present in Upper Cretaceous and Danian deep-marine deposits in the Basque–Cantabrian Basin of northern Spain. The presence and regularity of the succession of marl–limestone couplets is exceptional based on the macroscopic, microscopic and geochemical evidence collected. Five types of marl–limestone couplets are identified based on the colour, and a high maximum sedimentation rate (3.6 cm ka–1 ) is noted. The oxidizing activity of deep, cold-water masses is indicated by the oxygen isotope signal in the lower–upper Maastrichtian and Danian sections and the presence of the boreal inoceramid Spyridoceramus tegulatus. In theory, the variation in colour from grey to greenish-yellow, purple and pink up to red tones correlates with the Fe2+/(Fe2++Fe3+) ratio. It is interpreted as the possible palaeoenvironmental transit of particles that sediment out slowly in oxic environments when they circulate through cooler, oxidizing water masses. The colour is considered to be a depositional feature, and hematite, detected by X-ray diffraction, is the main staining agent, without discarding the possible redistribution of previous oxyhydroxides passing to hematite as a final product. The cell filling of the foraminifer shells does not incorporate appreciable amounts of Fe and Mg during diagenesis. Bacterial activity is detected using scanning electron microscopy images, both in the coccolith debris and in the detrital micas, although there is uncertainty as to its importance in the staining process.

Although much has been learned about the design of models of β-sheets during the last decade, modest fold stabilities in water and terminal fraying remain a feature of most β-hairpin peptides. In the case of hairpin capping, nature did not provide guidance for solving the problem. Some observations from prior turn capping designs, with further optimization, have provided a generally applicable, \"unnatural\" beta cap motif (alkanoyl-Trp at the N terminus and Trp-Thr-Gly at the C terminus) that provides a net contribution of 6 + kJ/mol to β-hairpin stability, surpassing all other interactions that stabilize β-hairpins including the covalent disulfide bond. The motif, made up entirely of natural residues, is specific to the termini of antiparallel β-strands and reduces fraying at the ends of hairpins and other β-sheet models. Utilizing this motif, 10- to 22-residue peptide scaffolds of defined stereochemistry that are greater than 98% folded in water have been prepared. The β-cap can also be used to staple together short antiparallel β-strands connected by a long flexible loop.

A 915-MHz wind profiler, a GPS receiver, and surface meteorological sites in and near California’s northern Central Valley (CV) provide the observational anchor for a case study on 23–25 October 2010. The study highlights key orographic influences on precipitation distributions and intensities across northern California during a landfalling atmospheric river (AR) and an associated Sierra barrier jet (SBJ). A detailed wind profiler/GPS analysis documents an intense AR overriding a shallow SBJ at ~750m MSL, resulting in record early season precipitation. The SBJ diverts shallow, pre-cold-frontal, incoming water vapor within the AR poleward from the San Francisco Bay gap to the northern CV. The SBJ ultimately decays following the passage of the AR and trailing polar cold front aloft. A statistical analysis of orographic forcing reveals that both the AR and SBJ are crucial factors in determining the amount and spatial distribution of precipitation in the northern Sierra Nevada and in the Shasta–Trinity region at the northern terminus of the CV. As the AR and SBJ flow ascends the steep and tall terrain of the northern Sierra and Shasta–Trinity region, respectively, the precipitation becomes enhanced. Vertical profiles of the linear correlation coefficient quantify the orographic linkage between hourly upslope water vapor flux profiles and hourly rain rate. The altitude of maximum correlation (i.e., orographic controlling layer) is lower for the shallow SBJ than for the deeper AR (i.e., 0.90 versus 1.15km MSL, respectively). This case study expands the understanding of orographic precipitation enhancement from coastal California to its interior. It also quantifies the connection between dry antecedent soils and reduced flood potential.