BackgroundSleep status, including sleep quality and nap duration, may be associated with frailty and cognitive impairment in older adults. Older adults living in nursing homes may be more prone to physical and cognitive frailties. This study aimed to investigate the association between sleep quality and nap duration, and cognitive frailty among older adults living in nursing homes.MethodsThis study included 1,206 older adults aged ≥ 60 years from nursing homes in Hunan province, China. A simple frailty questionnaire (FRAIL scale) was used and Mini-Mental State Examination was conducted to assess physical frailty and cognitive impairment, respectively, to confirm cognitive frailty. The Pittsburgh Sleep Quality Index was used to assess the sleep quality. Nap duration was classified as follows: no, short (≤30 min), and long (>30 min) napping. Multinomial logistic regression was conducted to estimate the odds ratio (OR) and 95% confidence interval (CI).ResultsThe prevalence of cognitive frailty among the older adults in nursing homes was 17.5%. Approximately 60.9% of the older adults had a poor sleep quality. Among the 1,206 participants, 43.9% did not take naps, 29.1% had short naps, and 26.9% had long naps. After adjusting for all covariates, poor sleep quality (OR 2.53; 95% CI 1.78–3.59; P < 0.001) and long nap duration (OR 1.77; 95% CI 1.19–2.64; P = 0.003) were associated with higher odds of cognitive frailty, but short nap duration (OR 0.60; 95% CI 0.40–0.89; P = 0.012) was associated with low prevalence of cognitive frailty.ConclusionPoor sleep quality and long nap duration are significantly associated with high risk of cognitive frailty among the older adults in nursing homes. Short nap duration was associated with low prevalence of cognitive frailty. However, these associations require further validation in older adults.Clinical trial registrationhttps://osf.io/57hv8.

Sugars are necessary for plant growth and fruit development. Cucumber (Cucumis sativus L.) transports sugars, mainly raffinose family oligosaccharides (RFOs), in the vascular bundle. As the dominant sugars in cucumber fruit, glucose and fructose are derived from sucrose, which is the product of RFO hydrolysis by α-galactosidases. Here, we characterized the cucumber alkaline α-galactosidase 2 (CsAGA2) gene and found that CsAGA2 has undergone human selection during cucumber domestication. Further experiments showed that the expression of CsAGA2 increases gradually during fruit development, especially in fruit vasculature. In CsAGA2-RNA interference (RNAi) lines, fruit growth was delayed because of lower hexose production in the peduncle and fruit main vascular bundle (MVB). In contrast, CsAGA2-overexpressing (OE) plants displayed bigger fruits. Functional enrichment analysis of transcriptional data indicated that genes related to sugar metabolism, cell wall metabolism, and hormone signaling were significantly downregulated in the peduncle and fruit MVBs of CsAGA2-RNAi plants. Moreover, downregulation of CsAGA2 also caused negative feedback regulation on source leaves, which was shown by reduced photosynthetic efficiency, fewer plasmodesmata at the surface between mesophyll cell and intermediary cell or between intermediary cell and sieve element, and downregulated gene expression and enzyme activities related to phloem loading, as well as decreased sugar production and exportation from leaves and petioles. The opposite trend was observed in CsAGA2-OE lines. Overall, we conclude that CsAGA2 is essential for cucumber fruit set and development through mediation of sugar communication between sink strength and source activity.

Aimed at improving upon the disadvantages of the single centralized Kalman filter for integrated navigation, including its fragile robustness and low solution accuracy, a nonlinear double model based on the improved decentralized federated extended Kalman filter (EKF) for integrated navigation is proposed. The multisensor error model is established and simplified in this paper according to the near-ground short distance navigation applications of small unmanned aerial vehicles (UAVs). In order to overcome the centralized Kalman filter that is used in the linear Gaussian system, the improved federated EKF is designed for multisensor-integrated navigation. Subsequently, because of the navigation requirements of UAVs, especially for the attitude solution accuracy, this paper presents a nonlinear double model that consists of the nonlinear attitude heading reference system (AHRS) model and nonlinear strapdown inertial navigation system (SINS)/GPS-integrated navigation model. Moreover, the common state parameters of the nonlinear double model are optimized by the federated filter to obtain a better attitude. The proposed algorithm is compared with multisensor complementary filtering (MSCF) and multisensor EKF (MSEKF) using collected flight sensors data. The simulation and experimental tests demonstrate that the proposed algorithm has a good robustness and state estimation solution accuracy.

Plant cystatins are cysteine proteinase inhibitors that play key roles in defense responses. In this work, we describe an unexpected role for the cystatin-like protein DEFORMED FLORAL BUD1 (CsDFB1) as a transcriptional regulator of local auxin distribution in cucumber (Cucumis sativus L.). CsDFB1 was strongly expressed in the floral meristems, floral primordia, and vasculature. RNA interference (RNAi)-mediated silencing of CsDFB1 led to a significantly increased number of floral organs and vascular bundles, together with a pronounced accumulation of auxin. Conversely, accompanied by a decrease of auxin, overexpression of CsDFB1 resulted in a dramatic reduction in floral organ number and an obvious defect in vascular patterning, as well as organ fusion. CsDFB1 physically interacted with the cucumber ortholog of PHABULOSA (CsPHB), an HD-ZIP III transcription factor whose transcripts exhibit the same pattern as CsDFB1. Overexpression of CsPHB increased auxin accumulation in shoot tips and induced a floral phenotype similar to that of CsDFB1-RNAi lines. Furthermore, genetic and biochemical analyses revealed that CsDFB1 impairs CsPHB-mediated transcriptional regulation of the auxin biosynthetic gene YUCCA2 and the auxin efflux carrier PIN-FORMED1, and thus plays a pivotal role in auxin distribution. In summary, we propose that the CsDFB1-CsPHB module represents a regulatory pathway for local auxin distribution that governs floral organogenesis and vascular differentiation in cucumber.

Amino acid transporters are the principal mediators of organic nitrogen distribution within plants and are essential for plant growth and development. Despite this importance, relatively few amino acid transporter genes have been explored and elucidated in cucumber (Cucumis sativus).Here, a total of 86 amino acid transporter genes were identified in the cucumber genome. We further identified Amino Acid Permease (AAP) subfamily members that exhibited distinct expression patterns in different tissues.We found that the CsAAP2 as a candidate gene encoding a functional amino acid transporter is highly expressed in cucumber root vascular cells. CsAAP2 knockout lines exhibited arrested development of root meristem, which then caused the delayed initiation of lateral root and the inhibition of root elongation. What is more, the shoot growth of aap2 mutants was strongly retarded due to defects in cucumber root development.Moreover, aap2 mutants exhibited higher concentrations of amino acids and lignin in roots. We found that the mutant roots had a stronger ability to acidize medium. Furthermore, in the aap2 mutants, polar auxin transport was disrupted in the root tip, leading to high auxin levels in roots. Interestingly, slightly alkaline media rescued their severely reduced root growth by stimulating auxin pathway.