To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Au Québec, la Société de l’assurance automobile du Québec (SAAQ) est la seule instance responsable de la délivrance d’un permis ou de son retrait.* Récemment, la SAAQ annonçait qu’elle retirait l’obligation d’évaluation par un médecin ou un ophtalmologiste/optométriste pour les conducteurs âgés de 75 ans, repoussant cette première évaluation médicale obligatoire à 80 ans (SAAQ, 2021b). On invoque qu’une telle décision permettrait de délester le réseau de la santé d’une charge d’évaluation et de bureaucratie supplémentaire. De plus, il est invoqué que très peu de conducteurs se voyaient retirer leurs permis de conduire à la suite de ces évaluations à la SAAQ. Au cours des dernières années, moins de 2% des personnes âgées de 75 ans voyaient leur permis de conduire suspendu à la suite d’un examen médical ou visuel (SAAQ, 2021a). À cet effet, il est mentionné que la majorité des modifications apportées au droit de conduire portait sur le port de verres correcteurs ou la réduction des heures permises de conduite.
This work presents a numerical investigation targeting to simulate the slice of a small aircraft cabin as an experimental facility with a controlled environment, to assess passenger comfort when exposed to high volatile organic compound (VOC) concentrations. The mixing and transport of chemical species are evaluated using computational fluid dynamics for 800 s of in-cabin actual flow time and measurements are taken every 10 s from selected computational nodes close to the passengers’ noses. The results are used to create a dataset that trains four different machine learning classifiers, namely, the Random Forest, Support Vector Machine, Logistic Regression and Naive Bayes, and their performance is compared. Moreover, an additional simulation of the cabin with a filtering system utilising high-efficiency particulate air and activated carbon filters is conducted, to evaluate the impact of the molecular weight of the compounds on their residence time, and compare it to the simulation without the filters. Results indicate that the model is insensitive to the inlet air mass flow variation and that the mass of the VOCs measured in the monitored computational nodes remains relatively unaffected, meaning that the impact of the air-conditioning system setting is minor. Additionally, a Boruta feature selection algorithm is used to determine the importance of each measurement of the simulation and to form a dataset that will train the four machine learning classifiers. Furthermore, the comparison of the two simulations, the one with and the one without the filters, indicates that the residence time (RT) of the compounds is independent of their molecular weight, as they all show equivalent percentile reductions, with the naphthalene and styrene showing a 28.5% and 28.3% reduction respectively, compared to the simulation without the filters. Finally, in-cabin flow irregularities are present, disrupting the flow symmetry and suggesting that not all passengers share the same traveling experience.
I discuss problems with Martin-Löf’s distinction between analytic and synthetic judgments in constructive type theory and propose a revision of his views. I maintain that a judgment is analytic when its correctness follows exclusively from the evaluation of the expressions occurring in it. I argue that Martin-Löf’s claim that all judgments of the forms $a : A$ and $a = b : A$ are analytic is unfounded. As I shall show, when A evaluates to a dependent function type $(x : B) \to C$, all judgments of these forms fail to be analytic and therefore end up as synthetic. Going beyond the scope of Martin-Löf’s original distinction, I also argue that all hypothetical judgments are synthetic and show how the analytic–synthetic distinction reworked here is capable of accommodating judgments of the forms $A \> \mathsf {type}$ and $A = B \> \mathsf {type}$ as well. Finally, I consider and reject an alternative account of analyticity as decidability and assess Martin-Löf’s position on the analytic grounding of synthetic judgments.
The Jurassic rocks of Gebel Maghara, northern Sinai, Egypt, contain a well-preserved and highly diverse macrobenthic fauna, dominated by bivalves. This fauna, particularly bivalves and gastropods, have received little attention in the last 100 years. In an attempt to provide a sound database on the marine bivalve diversity of Egypt during the Jurassic period, a first faunal group, the protobranch bivalves, is reviewed in detail. Sixteen taxa (three of them new), belonging to two orders, five families, and nine genera are systematically described and compared to closely related Jurassic taxa from various locations, particularly in Europe and India. New species are Nuculoma douvillei n. sp., N. sinaiensis n. sp., and Palaeoneilo aegyptiaca n. sp. In addition, Palaeonucula cuneiformis (J. de C. Sowerby), P. muensteri (Goldfuss), Dacryomya diana (d'Orbigny), D. lacryma (J. de. C. Sowerby), and Praesaccella juriana Cox are identified from Jurassic strata of Egypt for the first time. The younger records of the genus Palaeoneilo have not been accepted by some researchers, since almost all exhibit only limited features. The genus occurs with certainty in the Middle Jurassic (Bajocian‒Bathonian) rocks of Egypt, based on well-preserved external and internal characters. Similarly, Dacryomya and Ryderia from Bathonian‒Kimmeridgian rocks of Egypt are younger than previously recorded from other parts of the world. The identified genera have wide geographic ranges and have been reported from different faunal provinces, which suggests that latitudinal climate differences did not influence their distribution pattern to a great extent.
In the present study, the cryoprotective effects of Lolium perenne antifreeze protein (LpAFP) on the vitrification of bovine embryos were evaluated. In vitro-produced blastocysts were divided into two groups: the control group (CG) without the addition of LpAFP and the treatment group (TG) with the addition of 500 ng/ml of LpAFP in the equilibrium and vitrification solution. Vitrification was carried out by transferring the blastocysts to the equilibrium solution [7.5% ethylene glycol (EG) and 7.5% dimethyl sulfoxide (DMSO)] for 2 min and then to the vitrification solution (15% EG, 15% DMSO and 0.5M sucrose). The blastocysts were deposited on a cryotop device and submerged in liquid nitrogen. Warming was carried out in three steps in solutions with different sucrose concentrations (1.0, 0.5, and 0.0 M, respectively). Embryos were evaluated for re-expansion/hatching, the total cell count, and ultrastructural analysis. There was no significant difference in the re-expansion rate 24 h after warming; however, there was variation (P < 0.05) in the hatching rate in the TG and the total number of cells 24 h after warming was higher in the TG (114.87 ± 7.24) when compared with the CG (91.81 ± 4.94). The ultrastructural analysis showed changes in organelles related to the vitrification process but, in the TG, there was less damage to mitochondria and rough endoplasmic reticulum compared with the CG. In conclusion, the addition of 500 ng/ml of LpAFP during the vitrification of in vitro-produced bovine embryos improved the hatching rate and total cell number of blastocysts after warming and mitigated intracellular damage.
Darwinism and evolutionary theory have a bad track record in political theory, given their entanglements with fin-de-siècle militarist imperialisms, racialized hierarchies, and eugenic reformism. In colonial contexts, however, Darwinism had an entirely different afterlife as anticolonialists marshaled evolutionist frameworks to contest the parameters of colonial rule. This article exhumes just such an evolutionary anticolonialism in the political thought of Aurobindo Ghose, radical firebrand of the early Indian independence movement. I argue that Ghose drew on a nuanced reform Darwinism to criticize British imperialism and advance an alternative grounded in the Indian polity’s mutualism. Evolutionism formed a conceptual ecosystem framing his understanding of progress—national, civilizational, and spiritual—and reformulating the temporal and conceptual coordinates of the liberal empire he resisted. The article thus exposes the constructiveness of anticolonial politics, the hybridity of South Asian intellectual history, and the surprising critical potential of Darwinism in colonial settings.
We aim to describe older mens’ experiences with physical activity (PA) and their preferences for PA programs. We interviewed 14 men from a Canada-based PA intervention study called Men on the Move, and 5 men from a supplementary sample (who were not intervention participants). Content analysis was used to describe their experiences with PA and program preferences. The socio-ecological perspective and the hegemonic masculinity framework guided the research. PA barriers were low motivation, poor health, lack of time, interests other than PA and a lack of interest in PA, finances, lack of knowledge about PA, injury fear, social influences, inconvenience, weather, caregiving, built/natural environments, low-quality fitness instructors, and program structure. PA facilitators were chores, health, interest, time, motivation, social influences, active transportation, built/natural environments, good weather, program structure, and skilled/knowledgeable fitness instructors. PA program preferences were small group atmosphere, individualized attention/programming, equal number of men and women, sports programming, PA classes, and experienced instructors. Older men have distinct PA experiences. Promoting and designing programs that address their experiences may increase their PA.
Utilizing a fan-stirred chamber and two-dimensional particle image velocimetry, we analyse the modification of homogeneous and isotropic turbulence ($50 \leq Re_\lambda \leq 140$, with supplementary data out to $Re_\lambda = 310$, where $Re_\lambda$ is the longitudinal Taylor Reynolds number) induced by both a non-volatile (water) and a volatile (ethanol) isolated and anchored droplet in the range $(0.3 \leq d/\eta \leq 5.1)$, where $d/\eta$ is the ratio of droplet diameter to the Kolmogorov length scale. The dissipation rate, $\varepsilon$, is calculated via the corrected spatial gradient method, and the resultant fields of both turbulent kinetic energy, $k$, and $\varepsilon$ are presented as spatial heat maps and as shell averages, ${\overline {k_{\Delta r}}}$ and ${\overline {\varepsilon _{\Delta r}}}$, vs the radial coordinate normalized by the droplet radius, $r/R$. The dissipation rate near the water droplet surface may exceed the corresponding unladen flow value by a factor of twenty or more. The normalized radius of recovery, $r^*$, which designates the radial location where ${\overline {k_{\Delta r}}}$ or ${\overline {\varepsilon _{\Delta r}}}$ has returned to within 10 % of the unladen value, is reasonably expressed as $r^* \propto (d/\lambda )^{-C_2}$ in either case, where $\lambda$ is the longitudinal Taylor microscale and $C_2$ is a positive empirical fitting parameter. Recovery of ${\overline {k_{\Delta r}}}$ and ${\overline {\varepsilon _{\Delta r}}}$ may take up to 14 normalized radii when $d/\lambda$ is small. Trend line extrapolation suggests that the attenuation region becomes negligible as $d/\lambda \to 1$. Ethanol, which evaporates up to five times faster than water, induces a much smaller dissipation spike near the surface. The mass ejection phenomenon appears to reduce the strong near-surface damping of the radial root-mean-square component. However, the radius of recovery trend for fields surrounding a volatile ethanol droplet falls directly in line with the non-volatile water droplet data for both $k$ and $\varepsilon$, indicating that droplet vaporization has little effect on the far-field return to isotropy.
We experimentally evaluate whether active wall-normal surface deformations are suitable for the targeted control of very-large-scale motions (VLSMs) in a turbulent boundary layer at a friction Reynolds number of $Re_\tau =2600$. Circular surface deformations with a diameter $D$ roughly equal to the boundary layer thickness $\delta$ are generated periodically at a constant amplitude of $0.03\delta$ and at actuation frequencies of $St=0.05$ to 0.20, where $St$ is the Strouhal number based on $D$ and the free stream velocity $U_\infty$. The resulting impact on the flow was captured using high-speed particle image velocimetry and analysed using a triple decomposition. We find that the active surface deformations produce high- and low-speed streamwise velocity fluctuations that are concentrated along the centreline of the actuator. These motions have a negligible impact on the mean velocity profile downstream, i.e. they are truly high and low speed with respect to the unactuated base flow. The motions produced at $St\lesssim 0.1$ are comparable to synthetic VLSMs in terms of their lengths and widths but with a reduced wall-normal extent and rapidly decaying strength. These synthetic motions produce a strong modulation of the turbulence similar to that of the naturally occurring VLSMs. Most notably, we observe that synthetic high-speed motions with magnitudes of the order of $0.05U_\infty$ cause up to a 30 % reduction in turbulence production within the logarithmic layer. The strength and turbulence-modulating characteristics of the synthetic motions appear well suited for targeting the naturally occurring VLSMs locally using a control scheme.
How does racial diversity impact institutional outcomes and (in)equality? Discussions about diversity usually focus on how individuals’ identities shape their behavior, but diversity is a group-level characteristic. Scholars must, therefore, consider the relationship between group composition and the individual decisions that shape institutional outcomes. Using felony data from a large U.S. court system, I explore the relationship between racial diversity among the judges comprising a court and individual judges’ decisions. I find that as the percent of Black judges in a courthouse increases white judges are less likely to render incarceration sentences in cases with Black defendants. Increases in racial diversity decrease the Black–white gap in the probability of incarceration by up to 7 percentage points. However, I find no relationship between judge’s racial identities and disparities in their decisions. This study highlights the importance of conceptualizing diversity as a group characteristic and the relationship between institutional context and outcomes.
Debates over racial voting, and over policies to combat vote dilution, turn on the extent to which groups’ voting preferences differ and vary across geography. We present the first study of racial voting patterns in every congressional district (CD) in the United States. Using large-sample surveys combined with aggregate demographic and election data, we find that national-level differences across racial groups explain 60% of the variation in district-level voting patterns, whereas geography explains 30%. Black voters consistently choose Democratic candidates across districts, whereas Hispanic and white voters’ preferences vary considerably across geography. Districts with the highest racial polarization are concentrated in the parts of the South and Midwest. Importantly, multiracial coalitions have become the norm: in most CDs, the winning majority requires support from non-white voters. In arriving at these conclusions, we make methodological innovations that improve the precision and accuracy when modeling sparse survey data.
Increased intraindividual variability (IIV) in behavioral and cognitive performance is a risk factor for adverse outcomes but research concerning hemodynamic signal IIV is limited. Cortical thinning occurs during aging and is associated with cognitive decline. Dual-task walking (DTW) performance in older adults has been related to cognition and neural integrity. We examined the hypothesis that reduced cortical thickness would be associated with greater increases in IIV in prefrontal cortex oxygenated hemoglobin (HbO2) from single tasks to DTW in healthy older adults while adjusting for behavioral performance.
Method:
Participants were 55 healthy community-dwelling older adults (mean age = 74.84, standard deviation (SD) = 4.97). Structural MRI was used to quantify cortical thickness. Functional near-infrared spectroscopy (fNIRS) was used to assess changes in prefrontal cortex HbO2 during walking. HbO2 IIV was operationalized as the SD of HbO2 observations assessed during the first 30 seconds of each task. Linear mixed models were used to examine the moderation effect of cortical thickness throughout the cortex on HbO2 IIV across task conditions.
Results:
Analyses revealed that thinner cortex in several regions was associated with greater increases in HbO2 IIV from the single tasks to DTW (ps < .02).
Conclusions:
Consistent with neural inefficiency, reduced cortical thickness in the PFC and throughout the cerebral cortex was associated with increases in HbO2 IIV from the single tasks to DTW without behavioral benefit. Reduced cortical thickness and greater IIV of prefrontal cortex HbO2 during DTW may be further investigated as risk factors for developing mobility impairments in aging.
This paper discusses how the submergence ratio, defined as the ratio between the flow depth, D, and the height, h, of the solid rigid cylinders forming the array affects flow and turbulence structure inside and around a rectangular array of cylinders placed adjacent to one of the channel sidewalls. As the array becomes submerged, a vertical shear layer develops in between the top face of the array and the free surface, which strongly increases flow three-dimensionality and modifies how the momentum exchange between the array and the surrounding open water regions occurs with respect to the case of an emerged array where only a horizontal shear layer forms as part of the incoming flow approaching the array is deflected laterally. Eddy-resolving simulations are conducted for several values of the solid volume fraction, ϕ, and of the submergence ratio, 1.0 ≤ D/h ≤ 4.0. Similar to the limiting case of an emerged array (D/h = 1.0), the width- and depth-averaged streamwise velocity inside the array reaches a constant value after an initial adjustment region in the submerged-array cases. For D/h ≥ 1.33, the mean normal velocities through the top and side faces of the array do not become equal to zero downstream of the initial adjustment region. The flow inside the array reaches an equilibrium regime where the local flux of fluid leaving the array through its side face is balanced by the local flux of fluid entering the array through its top face. This regime is observed until close to the end of the array. For D/h ≥ 2.0, the horizontal shear layer vortices do not generate successive regions of high and low streamwise velocity and bed friction velocity inside the array, as is observed in the emerged cases. With respect to the emerged case, the size of the shear layer vortices and the shear layer width increase for low submergence ratios before decreasing rapidly for D/h ≥ 1.33. Significant three-dimensional effects are present inside the array and the horizontal shear layer for cases with both emerged and submerged arrays. In the ϕ = 0.08 cases, strong upwelling and downwelling motions are observed inside the array for D/h ≥ 1.33, while the circulation of the streamwise-oriented cell of secondary flow forming close to the lateral face of the array peaks when the submergence ratio is close to 1.33. For constant ϕ, the total streamwise drag force normalized with the height and width of the array increases with increasing submergence ratio. As the array submergence increases, the cylinders near the front of the array contribute less to the total force acting on the cylinders forming the array. For constant D/h, the total streamwise drag force acting on the array increases with ϕ for the submerged and emerged cases.
Psychedelics such as psilocybin reliably produce significantly altered states of consciousness with a variety of subjectively experienced effects. These include certain changes to perception, cognition, and affect,1 which we refer to here as the acute subjective effects of psychedelics. In recent years, psychedelics such as psilocybin have also shown considerable promise as therapeutic agents when combined with talk therapy, for example, in the treatment of major depression or substance use disorder.2 However, it is currently unclear whether the aforementioned acute subjective effects are necessary to bring about the observed therapeutic effects of psilocybin and other psychedelics. This uncertainty has sparked a lively—though still largely hypothetical—debate on whether psychedelics without subjective effects (“nonsubjective psychedelics” or “non-hallucinogenic psychedelics”) could still have the same therapeutic impact, or whether the acute subjective effects are in fact necessary for this impact to be fully realized.3,4,5
Human burials have been recovered from a wide variety of intra- and extramural settlement contexts at Neolithic period sites (3000–1200 BC) in southern India, yet formal cemeteries remain virtually unknown from this period. Research at MARP-79 in the Raichur District of the south Indian state of Karnataka, near the type-site of Maski, documents a large Neolithic cemetery, now with the largest number of radiometrically dated burials of any archaeological site in southern India. The cemetery demonstrates considerable, previously undocumented variation in mortuary ritual, involving new materials, technologies and burial practices, which challenge culture-historical models, pointing instead towards long-term incremental developments that alter how we understand the emergence of Neolithic social differences.
My first academic job in 1962 involved teaching a course on History of Civilization. We had a text that essentially involved Western Civilization with chapters on India, China, and Japan interspersed. Two years later, when I returned from my doctoral thesis research in Africa, my thesis supervisor, William Halperin, recommended me for a ten-week adult education group discussing William McNeill’s Rise of the West. I was stunned that in a history of Eurasia, McNeill devoted only five pages to Africa. The incorporation of Africa in world history has been slow. For many of us in that first generation to study African history in Europe and North America, the marginality of Africa in the study of history was sometimes what drew us to study it. (There were a small number of African-American historians who wrote about Africa, but they had little impact on history curricula outside the small world in which they operated.) As a graduate student, I did a field on the Expansion of Europe and was struck by the inferior quality of much that had been written about Africa, largely by missionaries and colonial administrators. Until the Foreign Area Fellowship Program sent me to the University of Wisconsin-Madison to “tool up” with Jan Vansina, I was oblivious to the work that scholars like Vansina, Oliver, and Curtin were doing. Once I began researching Africa, the excitement was that of creating a new field of historical research.