We consider the problem of sequential matching in a stochastic block model with several classes of nodes and generic compatibility constraints. When the probabilities of connections do not scale with the size of the graph, we show that under the Ncond condition, a simple max-weight type policy allows us to attain an asymptotically perfect matching while no sequential algorithm attains perfect matching otherwise. The proof relies on a specific Markovian representation of the dynamics associated with Lyapunov techniques.

Since the late 2010s, Rwanda has advertised its Visit Rwanda logo on the jerseys of prominent European football teams and has built new sports stadiums to host international sports competitions. Such strategies reflect the practice of sportswashing, which refers to the utilization of sports by political actors to gain global legitimacy while diverting attention from unjust processes occurring in their home countries. Dubinsky analyzes the effectiveness of Rwanda’s sportswashing through the concept of authoritarian image management, arguing that the mutual interests shared between authoritarian and Western actors facilitate the country’s sportswashing, despite the critiques it attracts.

States frequently use leadership decapitation in their domestic and cross-border counter-insurgency/terrorism operations, yet the literature is far from having a consensus regarding its effects. I argue that literature focuses on the military implications of decapitation (its implications for the organisation’s operational capabilities/ability to generate violence) at the expense of its implications for negotiations between insurgents and the state. Second, I argue that leadership arrest and killing are analytically distinct categories of leadership decapitation that can trigger different processes and outcomes and that an arrested leader’s possible role from the prison should be considered in the analysis since leadership arrest alters the leader’s incentives, resulting in a new bargaining game between the leader, the state, and the organisation. I empirically illustrate these arguments using the arrest of the leader of the Kurdistan Workers’ Party (PKK) Abdullah Öcalan as a theory-building case study. In the case study, I show that Abdullah Öcalan’s arrest was productive for terminating the conflict in the short run, whereas it was counter-productive in the medium and long run. These findings suggest that the literature may benefit from tracing the process closely, considering the dynamic nature of conflicts and the impact of decapitation on bargaining processes, without limiting the temporal scope of inquiry.

This article contributes to the understanding of why some management experiences of non-family CEOs (NF-CEOs) in privately owned family firms (POFFs) are successful, while others are not. It uses the flexible pattern-matching technique to examine seven case studies of POFFs with different experiences in recruiting NF-CEOs. Drawing on human capital specificity and heterogeneity, as well as socio-emotional wealth perspectives, our analysis suggests that NF-CEOs and owning families must invest time to gain knowledge of each other. Consequently, longer minimum tenures are required compared to non-FFs, making the alignment of NF-CEO and successor life cycles crucial for success. A cooperative and long-term-oriented personality of NF-CEOs is also relevant to fit the context of family businesses. This article is the first to adapt the specificity of human capital theory to the study of NF-CEOs.

Let $\mu _{M,D}$ be the self-similar measure generated by $M=RN^q$ and the product-form digit set $D=\{0,1,\ldots ,N-1\}\oplus N^{p_1}\{0,1,\ldots ,N-1\}\oplus \cdots \oplus N^{p_s}\{0,1,\ldots ,N-1\}$, where $R\geq 2$, $N\geq 2$, q, $p_i(1\leq i\leq s)$ are integers with $\gcd (R,N)=1$ and $1\leq p_1<p_2<\cdots <p_s<q$. In this paper, we first show that $\mu _{M,D}$ is a spectral measure with a model spectrum $\Lambda $. Then, we completely settle two types of spectral eigenvalue problems for $\mu _{M,D}$. In the first case, for a real t, we give a necessary and sufficient condition under which $t\Lambda $ is also a spectrum of $\mu _{M,D}$. In the second case, we characterize all possible real numbers t such that $\Lambda '\subset \mathbb {R}$ and $t\Lambda '$ are both spectra of $\mu _{M,D}$.

Let S and T be smooth projective varieties over an algebraically closed field k. Suppose that S is a surface admitting a decomposition of the diagonal. We show that, away from the characteristic of k, if an algebraic correspondence $T \to S$ acts trivially on the unramified cohomology, then it acts trivially on any normalized, birational and motivic functor. This generalizes Kahn’s result on the torsion order of S. We also exhibit an example of S over $\mathbb {C}$ for which $S \times S$ violates the integral Hodge conjecture.

This meta-analysis assesses the relationship between vitamin D supplementation and incidence of major adverse cardiovascular events (MACE). PubMed, Web of science, Ovid, Cochrane Library and Clinical Trials were used to systematically search from their inception until July 2024. Hazard ratios (HR) and 95 % CI were employed to assess the association between vitamin D supplementation and MACE. This analysis included five randomised controlled trials (RCT). Pooled results showed no significant difference in the incidence of MACE (HR: 0·96; P = 0·77) and expanded MACE (HR: 0·96; P = 0·77) between the vitamin D intervention group and the control group. Further, the vitamin D intervention group had a lower incidence of myocardial infarction (MI), but the difference was not statistically significant (HR: 0·88, 95 % CI: 0·77, 1·01; P = 0·061); nevertheless, vitamin D supplementation had no effect on the reduced incidence of stroke (P = 0·675) or cardiovascular death (P = 0·422). Among males (P = 0·109) and females (P = 0·468), vitamin D supplementation had no effect on the reduced incidence of MACE. For participants with a BMI < 25 kg/m2, the difference was not statistically significant (P = 0·782); notably, the vitamin D intervention group had a lower incidence of MACE for those with BMI ≥ 25 kg/m2 (HR: 0·91, 95 % CI: 0·83, 1·00; P = 0·055). Vitamin D supplementation did not significantly contribute to the risk reduction of MACE, stroke and cardiovascular death in the general population, but may be helpful for MI. Notably, the effect of vitamin D supplementation for MACE was influenced by BMI. Overweight/obese people should be advised to take vitamin D to reduce the incidence of MACE.

Hydrothermal vents are known to host unique faunal assemblages supported by chemosynthetic production; however, the fauna associated with inactive sulphide ecosystems remain largely uncharacterised across the global seafloor. In November 2023, a six-rayed starfish was collected from the Semenov hydrothermal field on the Mid-Atlantic Ridge. A combination of morphological and molecular methods has confirmed the identity of this species as Paulasterias mcclaini Mah et al. 2015 (Forcipulatida: Paulasteriidae), providing the first validated record of this family in the Atlantic Ocean. We present an updated morphological description of the species, alongside phylogenetic analysis of the COI, 16S, 12S, and H3 genetic markers. The biogeography of the family is discussed, and previously published records amended.

In experimental social science, precise treatment effect estimation is of utmost importance, and researchers can make design choices to increase precision. Specifically, block-randomized and pre-post designs are promoted as effective means to increase precision. However, implementing these designs requires pre-treatment covariates, and collecting this information may decrease sample sizes, which in and of itself harms precision. Therefore, despite the literature’s recommendation to use block-randomized and pre-post designs, it remains unclear when to expect these designs to increase precision in applied settings. We use real-world data to demonstrate a counterintuitive result: precision gains from block-randomized or pre-post designs can withstand significant sample loss that may arise during implementation. Our findings underscore the importance of incorporating researchers’ practical concerns into existing experimental design advice.