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.
The unsteady wake interference of unequal-height tandem finite wall-mounted cylinders (FWMCs) fully submerged in a turbulent boundary layer (TBL) was investigated using time-resolved particle image velocimetry. The aspect ratios of the cylinders were fixed at $h/d = 5.3$ for the upstream cylinder (UC) and $H/d = 7.0$ for the downstream cylinder (DC) to achieve a height ratio of $h/H = 0.75$, where d is the diameter of the cylinders. The Reynolds number based on the cylinder diameter was $Re = 5540$ and the submergence ratio was $\delta /H = 1.2$, where $\delta $ is the TBL thickness. Three main flow regimes of tandem FWMCs were examined by varying the centre-to-centre spacing ($s$) between the cylinders: extended-body ($s/d = 2$), reattachment ($s/d = 4$) and co-shedding ($s/d = 6$) regimes. These test cases denoted as SR2, SR4 and SR6, respectively, were compared with a reference isolated cylinder (SC) with an aspect ratio similar to that of the DC. Spatio-temporal analysis of the flow field showed that the gap region of SR2 is characterized by a strong downwash of alternating low- and high-momentum fluid induced by the approach flow that is deflected from the unsheltered portion of the DC. In contrast, the gap region of SR4 and SR6 exhibited both downwash and upwash flow with a saddle point that moves closer to the mid-height of the UC as the spacing ratio increases. The upwash and downwash shear layers were associated with small-scale vortices with Strouhal numbers larger than that of the Kármán vortex shedding in the spanwise shear layers. The wake structure behind the DC was significantly altered compared with the SC due to sheltering effects, and the spacing ratio had a significant impact on the spatio-temporal evolution of the vortices.
While China's efforts to maintain social stability by recruiting social elites and establishing Party branches in pre-existing social and market organizations have been thoroughly explored, much less attention has been devoted to how grassroots Party organizations (GRPOs) have proactively incubated society and constructed coherent, interrelated and systematic stability maintenance strategies to identify and eliminate social instability in its early stages and prevent its escalation. Using qualitative data gathered from local areas in China, we uncovered three major strategies used by GRPOs to manufacture society: incubating quasi-bureaucratic organizations, co-opting community elites and embedding Party organizations in market and social organizations. In general, GRPOs manufacture society for three reasons: to revitalize the mobilization capacity of the party-state; to increase the available social resources for grassroots authorities; and to establish an input mechanism for citizens. This study not only provides empirical data on how China's stability maintenance regime works in practice but also calls for a rethinking of the capacity of authoritarian resilience.
To evaluate the utility of selective reactive whole-genome sequencing (WGS) in aiding healthcare-associated cluster investigations.
Design:
Mixed-methods quality-improvement study.
Setting:
Thes study was conducted across 8 acute-care facilities in an integrated health system.
Methods:
We analyzed healthcare-associated coronavirus disease 2019 (COVID-19) clusters between May 2020 and July 2022 for which facility infection prevention and control (IPC) teams selectively requested reactive WGS to aid the epidemiologic investigation. WGS was performed with real-time results provided to IPC teams, including genetic relatedness of sequenced isolates. We conducted structured interviews with IPC teams on the informativeness of WGS for transmission investigation and prevention.
Results:
In total, 8 IPC teams requested WGS to aid the investigation of 17 COVID-19 clusters comprising 226 cases and 116 (51%) sequenced isolates. Of these, 16 (94%) clusters had at least 1 WGS-defined transmission event. IPC teams hypothesized transmission pathways in 14 (82%) of 17 clusters and used data visualizations to characterize these pathways in 11 clusters (65%). The teams reported that in 15 clusters (88%), WGS identified a transmission pathway; the WGS-defined pathway was not one that was predicted by epidemiologic investigation in 7 clusters (41%). WGS changed the understanding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission in 8 clusters (47%) and altered infection prevention interventions in 8 clusters (47%).
Conclusions:
Selectively utilizing reactive WGS helped identify cryptic SARS-CoV-2 transmission pathways and frequently changed the understanding and response to SARS-CoV-2 outbreaks. Until WGS is widely adopted, a selective reactive WGS approach may be highly impactful in response to healthcare-associated cluster investigations.
We examine the influence of national politics and changing racial demographics on school board elections. We identify the districts where candidates campaigned on Critical Race Theory, COVID response, or parent control/transparency (what we call “conflict elections”) and examine two related questions. First, what characteristics define school districts that had elections involving these issues? Second, in the places that had conflict elections, how frequently did “conflict candidates” win, and what factors influenced their odds of winning? Utilizing a unique dataset of all school board elections in Wisconsin in 2022, we find that Republican presidential vote share is positively related to both the probability that a school district had a conflict election and that a conflict candidate won. We also find that in communities where the white population declined between 2010 and 2020, there was a higher likelihood that a conflict candidate won compared to communities where the size of the white population grew. Overall, our analysis confirms that school board elections are increasingly mirroring nationalized trends in other elections.
This study aimed to investigate the structural and metabolic changes in cumulus cells of underweight women and their effects on oocyte maturation and fertilization. The cytoplasmic ultrastructure was analyzed by electron microscopy, mitochondrial membrane potential by immunofluorescence, and mitochondrial DNA copy number by relative quantitative polymerase chain reaction. The expression of various proteins including the oxidative stress-derived product 4-hydroxynonenal (4-HNE) and autophagy and apoptosis markers such as Vps34, Atg-5, Beclin 1, Lc3-I, II, Bax, and Bcl-2 was assessed and compared between groups. Oocyte maturation and fertilization rates were lower in underweight women (P < 0.05), who presented with cumulus cells showing abnormal mitochondrial morphology and increased cell autophagy. Compared with the mitochondrial DNA copies of the control group, those of the underweight group increased but not significantly. The mitochondrial membrane potential was similar between the groups (P = 0.8). Vps34, Atg-5, Lc3-II, Bax, and Bcl-2 expression and 4-HNE levels were higher in the underweight group compared with the control group (P < 0.01); however, the Bax/Bcl-2 ratio was lower in the underweight group compared with the control group (P = 0.031). Additionally, Beclin 1 protein levels were higher in the underweight group compared with the control group but without statistical significance. In conclusion, malnutrition and other conditions in underweight women may adversely affect ovulation, and the development, and fertilization of oocytes resulting from changes to the intracellular structure of cumulus cells and metabolic processes. These changes may lead to reduced fertility or unsatisfactory reproduction outcomes in women.
We study symmetric and antisymmetric tensor products of Hilbert-space operators, focusing on norms and spectra for some well-known classes favored by function-theoretic operator theorists. We pose many open questions that should interest the field.
The exit of the United Kingdom from the European Union (EU) single market and customs union has adversely affected trade prospects of many developing economies that depended on the UK market for their exports. This paper investigates the impact of Brexit on African countries' exports to the UK. The comparison is based upon trade between the set of African countries which export most to the UK and the EU. It provides a quantitative assessment of the trade effect through the use of descriptive analysis and empirical estimations by employing the difference-in-difference (DID) estimation approach. The descriptive analysis finds that the share of African exports sent to the UK has declined since the Brexit announcement in 2016. The empirical estimations using the DID approach also demonstrate a drop of 20–30% in African countries exports to the UK relative to the EU-27 in this period. These results hold to a battery of robustness checks, including the use of an alternative estimation approach, varying sample size, and the use of alternative counterfactuals. We further show that the trade flows started to drop immediately after the announcement of the Brexit referendum in 2015 but the main drop came after the Brexit referendum results became evident. These findings imply the need for policy intervention and support for African countries to revitalize their trade flows and alleviate the unintended effects of this trade shock.
La maladie d’Alzheimer se manifeste par des troubles de la mémoire et un déclin cognitif plus général, le plus souvent associés à des troubles de l’humeur et du comportement. Les traitements médicamenteux ayant une efficacité assez modeste, il apparaît nécessaire de leur associer une prise en charge non pharmacologique. La méditation de pleine conscience, qui a des effets bénéfiques sur le fonctionnement cognitif et sur l’état émotionnel, semble être une piste intéressante. Cette revue de littérature narrative se propose de recenser les études ayant testé l’efficacité d’une intervention basée sur la pleine conscience auprès de personnes souffrant de la maladie d’Alzheimer ou à risque de développer cette maladie. Il apparaît que ces interventions présentent un intérêt pour réduire les symptômes cognitifs (troubles attentionnels et mnésiques notamment) et émotionnels (affects dépressifs et anxiété en particulier). Cependant, elles nécessitent un certain nombre de modifications pour être adaptées à ce public.
Age dynamics of the ability of cercariae of two digenean species, Himasthla elongata (Himasthlidae) and Renicola parvicaudatus (Renicolidae), to infect the second intermediate host (SIH), mussels (Mytilus edulis), was investigated experimentally. This is the first study of this kind made on cercariae transmitted in the intertidal of the northern seas. The larvae of all tested ages (from 0.5 to 6 hr) were equally successful in infecting mussels. This finding disagrees with the literature data on cercariae of several freshwater digeneans, which are practically incapable of infecting the SIH during the first 1–3 hr of life. The presence of a time delay before the attainment of the maximum infectivity (TDMI) may be associated with the need for physiological maturation of cercariae in the very beginning of their life in the environment, the need for their broad dispersion, and the prevention of superinfection of the downstream host. The absence of TDMI in the cercariae examined in our study could be associated with the instability of environmental factors in the marine intertidal (wave impact, tidal currents). These factors promote a broad dispersion of cercariae in the intertidal biotope and prevent superinfection of potential SIHs. Biological and behavioural features may also play a role. We hypothesize that the presence or absence of TDMI does not depend on the taxonomic affiliation of the cercariae but is determined by the transmission conditions.
A rigid object moving in a viscous fluid and in close proximity to an elastic wall experiences self-generated elastohydrodynamic interactions. This has been the subject of intense research activity, with recent and growing attention given to the particular case of elastomeric and gel-like substrates. Here, we address the situation where the elastic wall is replaced by a capillary surface. Specifically, we analyse the lubrication flow generated by the prescribed normal motion of a rigid infinite cylinder near the deformable interface separating two immiscible and incompressible viscous fluids. Using a combination of analytical and numerical treatments, we compute the emergent capillary-lubrication force at leading order in capillary compliance, and characterize its dependencies with the interfacial tension, viscosities of the fluids, and length scales of the problem. Interestingly, we identify two main contributions: (i) a velocity-dependent adhesive-like force; (ii) an acceleration-dependant inertia-like force. Our results may have implications for the mobility of colloids near complex interfaces and for the motility of confined microbiological entities.
We prove some conditions for higher-dimensional algebraic fibering of pro-p group extensions, and we establish corollaries about incoherence of pro-p groups. In particular, if $1 \to K \to G \to \Gamma \to 1$ is a short exact sequence of pro-p groups, such that $\Gamma $ contains a finitely generated, non-abelian, free pro-p subgroup, K a finitely presented pro-p group with N a normal pro-p subgroup of K such that $K/ N \simeq \mathbb {Z}_p$ and N not finitely generated as a pro-p group, then G is incoherent (in the category of pro-p groups). Furthermore, we show that if K is a finitely generated, free pro-p group with $d(K) \geq 2$, then either $\mathrm{Aut}_0(K)$ is incoherent (in the category of pro-p groups) or there is a finitely presented pro-p group, without non-procyclic free pro-p subgroups, that has a metabelian pro-p quotient that is not finitely presented, i.e., a pro-p version of a result of Bieri–Strebel does not hold.
In recent decades, secularism has emerged as one of the most studied concepts in sociocultural anthropology, and Egypt a primary site of its analysis. This article considers trends in Egypt’s modern and contemporary history in order to complicate the great explanatory power some anthropological works have granted to secularism. Above all else, it interrogates the manner in which the state’s regulation of religion (which is the defining feature of Asadian conceptions of secularism) has unfolded in recent Egyptian history. First, I survey the different ways scholars have portrayed secularism in Egypt, focusing in particular on the insights and limitations of Asadian theories. A second section employs ethnographic data to uncover how ordinary Egyptians in the provincial capital of Beni Suef have experienced state power, religion, and secularism in their everyday lives. Contextualizing these ethnographic perspectives alongside several prominent instances of state violence between 2011 and 2013, I elucidate how, rather than typifying a secular state, Egyptian politics, above all else, have been driven by an opportunistic realpolitik. My final section brings historical and ethnographic perspectives into sustained conversation to argue that the state regulation anthropologists sometimes frame as secularism is better conceptualized as a form of state centralization. I conclude, in turn, that political developments in modern Egypt have most often been shaped by flexible national and imperial interests.
A breeding programme of aromatic vanilla, dating back to 1944, was conducted in Ambohitsara, Antalaha, SAVA (Sambava, Antalaha, Vohemara, Andapa) – Madagascar. Imported, local, wild and cultivated vanillas were used as progenitors and thousands of hybrids were generated. However, this germplasm has not undergone any genetic evaluation, and it appears that these valuable genetic resources have been dispersed or lost after the end of the programme (2000). This study aims to investigate the genetic diversity and structure of rescued genotypes currently held in a local collection in Antalaha. Double digest restriction associated-site (RAD)-seq (ddRAD)-seq protocol was applied, providing 865 million read sequences from 56 accessions. The ddRAD sequences have been deposited to the SRA archive of NCBI. From the data, 23,701 filtered concordant common Single Nucleotide Polymorphisms (SNPs) were identified using the three widely used tools (Stacks, BCFtools, Genome Analysis ToolKit - GATK) for short-read library sequencing. These SNPs were used for germplasm evaluation. Clustering analysis segregated samples into five genetic groups: Vanilla planifolia, Vanilla pompona, hybrid Tsitaitra, Vanille Banane and the phenotype Tsivaky. Our analysis revealed distinct subgroups within V. pompona and Tsitaitra, emphasizing the importance of further characterization to accurately reflect the genetic diversity and facilitate better utilization of these accessions in future research and germplasm management. The presence of private alleles in all groups (from 487 to 2866) indicated that populations were diverging and represented a large gene pool that could be useful for future breeding efforts. The genetic data obtained from this study offers valuable insights into the genetic diversity and structure of the vanilla population, with potential applications in breeding and conservation efforts.
This article examines the migration and expropriation policies of Guatemala's revolutionary governments toward Germans present in the country during the postwar years and the start of the Cold War. It reconstructs the challenges around the domestic and international articulations of their strategy. Revolutionary governments’ concerted efforts to confiscate valuable land and condition the return of German-Guatemalans classified as ‘dangerous’ can be interpreted as part of a cohesive plan to regain control of strategic domestic resources for future redistribution. It also reflects financial policies that have both electoral and financial purposes. The article is built around newly available judicial, legislative, and consular (France) Guatemalan sources, along with personal letters from Guatemala's top politicians, and complemented by Mexican, Chilean, Argentine, British, and US diplomatic documents. In methodological terms, this article shows the importance of articulating long-term processes, here the nineteenth-century German presence in Guatemala, in the context of historical junctures such as the end of World War II and the beginning of the Cold War. It also draws attention to the importance of analyzing events on domestic, regional and global scales to understand foreign policy-making. This article enriches an already complex set of global, regional, and domestic interactions of the postwar period, as well as the role of Guatemala during that time.