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In the context of large off-shore wind farms, power production is influenced greatly by the turbine array's interaction with the atmospheric boundary layer. One of the most influencing manifestations of such complex interaction is the increased level of shear stress observed within the farm. This leads to higher momentum fluxes that affect the wind speed at the turbine locations and in the cluster wake. At the wind farm entrance, an internal boundary layer (IBL) grows due to the change in effective roughness imposed by the wind turbines, and for large enough clusters, this can reach the unperturbed boundary layer height in what is referred to as the fully developed regime. Downwind, a second IBL starts growing, while the shear stress profile decays exponentially to its unperturbed state. In the present study, we propose a simple analytical model for the vertical profile of the horizontal shear stress components in the three regions identified above. The model builds upon the top-down model of Meneveau (J. Turbul., vol. 13, 2012, N7), and assumes that the flow develops in a conventionally neutral boundary layer. The proposed parametrization is verified successfully against large-eddy simulations, demonstrating its ability to capture the vertical profile of horizontal shear stress, and its evolution both inside and downwind of the wind farm. Our findings suggest that the developed model can prove extremely useful to enhance the physical grounds on which new classes of coupled wind farm engineering models are based, leading to a better estimation of meso-scale phenomena affecting the power production of large turbine arrays.
We construct an autoregressive moving average (ARMA) model consisting of the history and random effects for the streamwise velocity fluctuation in boundary-layer turbulence. The distance to the wall and the boundary-layer thickness determine the time step and the order of the ARMA model, respectively. Based on the autocorrelation's analytical expression of the ARMA model, we obtain a global analytical expression for the second-order structure function, which asymptotically captures the inertial, dynamic and large-scale ranges. Specifically, the exponential autocorrelation of the ARMA model arises from the autoregressive coefficients and is modified to logarithmic behaviour by the moving-average coefficients. The asymptotic expressions enable us to determine model coefficients by existing parameters, such as the Kolmogorov and the Townsend–Perry constants. A consequent double-log expression for the characteristic length scale is derived and is justified by direct numerical simulation data with $Re_\tau \approx 5200$ and field-measured neutral atmospheric surface layer data with $Re_\tau \sim O(10^6)$ from the Qingtu Lake Observation Array site. This relation is robust because it applies to $Re_\tau$ from $O(10^4)$ to $O(10^6)$, and even when the statistics of natural ASL deviate from those of canonical boundary-layer turbulence, e.g. in the case of imbalance in energy production and dissipation, and when the Townsend–Perry constant deviates from traditional values.
For a subset $A$ of an abelian group $G$, given its size $|A|$, its doubling $\kappa =|A+A|/|A|$, and a parameter $s$ which is small compared to $|A|$, we study the size of the largest sumset $A+A'$ that can be guaranteed for a subset $A'$ of $A$ of size at most $s$. We show that a subset $A'\subseteq A$ of size at most $s$ can be found so that $|A+A'| = \Omega (\!\min\! (\kappa ^{1/3},s)|A|)$. Thus, a sumset significantly larger than the Cauchy–Davenport bound can be guaranteed by a bounded size subset assuming that the doubling $\kappa$ is large. Building up on the same ideas, we resolve a conjecture of Bollobás, Leader and Tiba that for subsets $A,B$ of $\mathbb{F}_p$ of size at most $\alpha p$ for an appropriate constant $\alpha \gt 0$, one only needs three elements $b_1,b_2,b_3\in B$ to guarantee $|A+\{b_1,b_2,b_3\}|\ge |A|+|B|-1$. Allowing the use of larger subsets $A'$, we show that for sets $A$ of bounded doubling, one only needs a subset $A'$ with $o(|A|)$ elements to guarantee that $A+A'=A+A$. We also address another conjecture and a question raised by Bollobás, Leader and Tiba on high-dimensional analogues and sets whose sumset cannot be saturated by a bounded size subset.
Cognition in MCI has responded poorly to pharmacological interventions, leading to use of computerized training. Combining computerized cognitive training (CCT) and functional skills training software (FUNSAT) produced improvements in 6 functional skills in MCI, with effect sizes >0.75. However, 4% of HC and 35% of MCI participants failed to master all 6 tasks. We address early identification of characteristics that identify participants who do not graduate, to improve later interventions.
Methods:
NC participants (n = 72) received FUNSAT and MCI (n = 92) participants received FUNSAT alone or combined FUNSAT and CCT on a fully remote basis. Participants trained twice a week for up to 12 weeks. Participants “graduated” each task when they made one or fewer errors on all 3–6 subtasks per task. Tasks were no longer trained after graduation.
Results:
Between-group comparisons of graduation status on baseline completion time and errors found that failure to graduate was associated with more baseline errors on all tasks but no longer completion times. A discriminant analysis found that errors on the first task (Ticket purchase) uniquely separated the groups, F = 41.40, p < .001, correctly classifying 94% of graduators. An ROC analysis found an AUC of .83. MOCA scores did not increase classification accuracy.
Conclusions:
More baseline errors, but not completion times, predicted failure to master all FUNSAT tasks. Accuracy of identification of eventual mastery was exceptional. Detection of risk to fail to master training tasks is possible in the first 15 minutes of the baseline assessment. This information can guide future enhancements of computerized training.
This article exploits two newspaper archives to track economic policy uncertainty in Spain from 1905–1945. We find that the outbreak of the Civil War in 1936 was anticipated by a striking upward level shift of uncertainty in both newspapers. We study the reasons for this shift through a natural language processing method, which allows us to leverage expert opinion to track specific issues in our newspaper archives. We find a strong empirical link between increasing uncertainty and the rise of divisive political issues like socio-economic conflict. This holds even when exploiting content differences between the two newspapers in our corpus.
Wall-pressure fluctuations are a practically robust input for real-time control systems aimed at modifying wall-bounded turbulence. The scaling behaviour of the wall-pressure–velocity coupling requires investigation to properly design a controller with such input data so that it can actuate upon the desired turbulent structures. A comprehensive database from direct numerical simulations (DNS) of turbulent channel flow is used for this purpose, spanning a Reynolds-number range $Re_\tau \approx 550\unicode{x2013}5200$. Spectral analysis reveals that the streamwise velocity is most strongly coupled to the linear term of the wall pressure, at a Reynolds-number invariant distance-from-the-wall scaling of $\lambda _x/y \approx 14$ (and $\lambda _x/y \approx 8$ for the wall-normal velocity). When extending the analysis to both homogeneous directions in $x$ and $y$, the peak coherence is centred at $\lambda _x/\lambda _z \approx 2$ and $\lambda _x/\lambda _z \approx 1$ for $p_w$ and $u$, and $p_w$ and $v$, respectively. A stronger coherence is retrieved when the quadratic term of the wall pressure is concerned, but there is only little evidence for a wall-attached-eddy type of scaling. An experimental dataset comprising simultaneous measurements of wall pressure and velocity complements the DNS-based findings at one value of $Re_\tau \approx 2$k, with ample evidence that the DNS-inferred correlations can be replicated with experimental pressure data subject to significant levels of (acoustic) facility noise. It is furthermore shown that velocity-state estimations can be achieved with good accuracy by including both the linear and quadratic terms of the wall pressure. An accuracy of up to 72 % in the binary state of the streamwise velocity fluctuations in the logarithmic region is achieved; this corresponds to a correlation coefficient of $\approx$0.6. This thus demonstrates that wall-pressure sensing for velocity-state estimation – e.g. for use in real-time control of wall-bounded turbulence – has merit in terms of its realization at a range of Reynolds numbers.
Cartesian pictures of the human self and act-centred understandings of ethics dominate modern thought. Throughout his work, Herbert McCabe challenges these, and as such remains an important resource for philosophical and theological ethics. This paper lays out McCabe’s philosophical anthropology, showing how he draws on Wittgenstein to revive a Thomist account of the human person. It then shows how this anthropology feeds into a philosophical ethics, focused on human flourishing and the possibility of life being meaningful. This, in turn, underwrites a theological ethics, according to which the human person flourishes ultimately through graced participation in the divine life. The paper concludes with a discussion of McCabe’s account of faith as participation in the divine self-knowledge.
This paper estimates the migratory and fertility effects of the federal Relocation Program, which attempted to move Native American individuals to urban areas under the promises of financial assistance and job training. I find the Relocation Program increased the Native American population in the target cities by more than 100,000 people. I also find that second- and third-generation Native American women living in cities have a 50 percent lower fertility rate than those living in areas with historically large Native American populations. These findings indicate that this program meaningfully shifted the spatial distribution of the Native American population.
The epidemiological picture of Taenia saginata infections in Kenya is fragmented with limited available data. Although Sarcocystis species are significant meat-borne parasites, few studies have explored their occurrence in Kenya. This study aimed to estimate the occurrence of bovine cysticercosis and screen for the presence of Sarcocystis spp. A meat inspection-based survey was conducted in ten abattoirs in Narok County, Kenya, and inspection for T. saginata cysticerci was limited to the Triceps brachii muscle. The apparent occurrence of the parasite was 5.4% (95% CI, 3.8, 7.6, n=573). Molecular confirmation of T. saginata was done via nested polymerase chain reaction targeting the mitochondrial 12S ribosomal RNA gene and restricted fragment length polymorphism. Sarcocystis species were identified using a multiplex polymerase chain reaction method targeting the 18S ribosomal RNA gene sequences and the mitochondrial cytochrome c oxidase subunit I gene. Of the 31 cystic lesions tested, 26/31 (83.9%) were confirmed to be T. saginata.Sarcocystis cruzi and S. hominis were detected in 8/31 (25.8%) and 1/31 (3.2%) of the cystic lesions, respectively. Co-infections of S. cruzi and T. saginata were found in 6/31 lesions (19.4%). The confirmation of bovine cysticercosis and S. hominis is suggestive of the presence of risky culinary and sanitation practices that facilitate transmission. This is the first report and molecular confirmation of Sarcocystis spp. in cattle in the country. The presence of both zoonotic S. hominis and pathogenic S. cruzi highlights an underexplored concern of veterinary and human health significance, warranting further epidemiological investigation.
In recent decades, sovereignty has come under increased academic scrutiny for being a Eurocentric notion antithetical to emancipatory politics, leading critical theory scholars to call for an overcoming or even abandonment of the concept. Paradoxical as it may seem, it nonetheless remains an appealing ideal for many colonised peoples. Indigenous activists and scholars have actively re-appropriated the language of sovereignty to encapsulate and advance Indigenous political aspirations. This paper discusses how Māori, Aotearoa/New Zealand’s Indigenous people, navigate their relations to the concept in their contemporary political discourses pursuing self-governance. Building on interviews with Māori leaders, scholars, and activists, it offers empirical insights into Indigenous political thought’s engagement with the idea of sovereignty. It highlights an ambivalence oscillating between rejection and rearticulation present both in Indigenous theorising and Māori politics. From an analysis of Māori contemporary conceptual strategies, this paper suggests that Yarimar Bonilla’s notion of ‘strategic entanglement’ offers a productive account to comprehend the approached Māori actors’ deployment of the sovereignty concept, and possibly that of Indigenous peoples beyond Aotearoa. This paper thus highlights the continued relevance of the sovereignty framework, both analytically and politically, to meaningfully engage with contemporary Indigenous politics.
Dancing offers several health and wellness benefits for older adults: it may promote physical literacy (PL) and positively influence the aging process. Yet, limited research considers the perspectives of those with experience working with older adults and in community dance programming.
Objective:
The purpose of this study was to understand program experts’ perspectives on how older adult community dance can promote PL and contribute to age-friendly cities and community initiatives.
Methods and Findings:
Four themes were identified from semi-structured interviews with five program experts: (1) expert instructors tailor classes to participants’ needs and interests; (2) the heart of what draws us to dancing: authentic experience and social connection; (3) elitist, ableist, and gendered assumptions of dance prevent social inclusion of older adults in dancing spaces; and (4) collaboration across sectors is needed to offer accessible, sustainable, and valued dance programming.
Discussion:
Recommendations for developing and implementing older adult community dance programming are described.
The rise in the number of automated robotic kitchens accelerated the need for advanced food handling system, emphasizing food analysis including ingredient classification pose recognition and assembling strategy. Selecting the optimal piece from a pile of similarly shaped food items is a challenge to automated meal assembling system. To address this, we present a constructive assembling algorithm, introducing a unique approach for food pose detection–Fast Image to Pose Detection (FI2PD), and a closed-loop packing strategy. Powered by a convolutional neural network (CNN) and a pose retrieval model, FI2PD is adept at constructing a 6D pose from only RGB images. The method employs a coarse-to-fine approach, leveraging the CNN to pinpoint object orientation and position, alongside a pose retrieval process for target selection and 6D pose derivation. Our closed-loop packing strategy, aided by the Item Arrangement Verifier, ensures precise arrangement and system robustness. Additionally, we introduce our FdIngred328 dataset of nine food categories ranging from fake foods to real foods, and the automatically generated data based on synthetic techniques. The performance of our method for object recognition and pose detection has been demonstrated to achieve a success rate of 97.9%. Impressively, the integration of a closed-loop strategy into our meal-assembly process resulted in a notable success rate of 90%, outperforming the results of systems lacking the closed-loop mechanism.
Due to a dearth of data, nineteenth century lending to sovereign borrowers was a blind date. We argue this is the reason for collateral pledges found in contemporary lending covenants, which enabled not execution, but the production of reliable fiscal data. Lawyers injected collateral clauses in sovereign debt covenants to permit credible disclosure of hard-to-access tax data. The study foregrounds the importance of big law firms as financial intermediaries and information producers. It also contributes a new view on the role played by contracts in sovereign debt.
“No [underwriting] firm can take precautions against the repudiation of a [sovereign] hypothecation.”
Lack of water at limiting levels results in drought stress, which may have an impact on the various stages of a crop's life cycle. Four different genotypes of snapmelon (Cucumis melo L. var. momordica) responded differently to 0, 7 and 21 d of simulated drought stress. Information was collected on a range of morpho-physiological, biochemical and molecular characteristics. Each genotype had longer roots, though BAM-VR-312 had the longest roots overall. As the severity of the drought grew, the net photosynthetic rate (Pn) and stomatal conductance (Gs) dropped. In BAM-VR-312, a smaller decline in relative water content (RWC) was recorded, despite the fact that drought stress caused a significant fall in RWC. BAM-VR-312 had smaller accumulations of electrolyte leakage, hydrogen peroxide, phenol and malondialdehyde, although proline content was greater. A decrease in photosynthetic pigments was noted, though BAM-VR-312 had the least reduction. Antioxidant enzyme activity increased in BAM-VR-312, as evidenced by records of ascorbate peroxidase, catalase, guaiacol peroxidase, glutathione reductase and superoxide dismutase. Similarly, expression level of their respective genes was recorded highest in BAM-VR-312. Overall, the study clearly identified distinct genotype based on morpho-physiological, biochemical and molecular properties under drought stress and revealed that the genotype BAM-VR-312 had more efficient drought tolerance mechanisms than the other genotypes under the drought stress condition.
Infertility affects 15% of all couples worldwide and 50% of cases of infertility are solely due to male factors. A decrease in motility in the semen is considered one of the main factors that is directly related to infertility. The use of supplementation to improve the overall sperm quality has become increasingly popular worldwide. The purpose of this study was to evaluate whether sperm motility was affected by the combination of serotonin (5-HT), selenium (Se), zinc (Zn), and vitamins D, and E supplementation. Semen samples were incubated for 75 min at 37°C in medium containing varying concentrations of 5-HT, Se, Zn, vitamin D, and E. 5-HT (200 μM), Se (2 μg/ml), Zn (10 μg/ml), vitamin D (100 nM), and vitamin E (2 mmol) have also been shown to increase progressive sperm motility. Three different mixtures of supplements were also tested for their combined effects on sperm motility and reactive oxygen species (ROS) production. While the total motility in the control group was 71.96%, this was found to increase to 82.85% in the first mixture. In contrast the average ROS level was 8.97% in the control group and decreased to 4.23% in the first mixture. Inclusion of a supplement cocktail (5-HT, Se, Zn, vitamins D and E) in sperm processing and culture medium could create an overall improvement in sperm motility while decreasing ROS levels during the incubation period. These molecules may enhance the success of assisted reproduction techniques when present in sperm preparation medium.