Gravitational self-force and the effective-one-body formalism between the innermost stable circular orbit and the light ring

We compute the conservative piece of the gravitational self-force (GSF) acting on a particle of mass m_1 as it moves along an (unstable) circular geodesic orbit between the innermost stable circular orbit (ISCO) and the light ring of a Schwarzschild black hole of mass m_2>> m_1. More precisely, we construct the function h_{uu}(x) = h_{\mu\nu} u^{\mu} u^{\nu} (related to Detweiler's gauge-invariant "redshift" variable), where h_{\mu\nu} is the regularized metric perturbation in the Lorenz gauge, u^{\mu} is the four-velocity of m_1, and x= [Gc^{-3}(m_1+m_2)\Omega]^{2/3} is an invariant coordinate constructed from the orbital frequency \Omega. In particular, we explore the behavior of h_{uu} just outside the "light ring" at x=1/3, where the circular orbit becomes null. Using the recently discovered link between h_{uu} and the piece a(u), linear in the symmetric mass ratio \nu, of the main radial potential A(u,\nu) of the Effective One Body (EOB) formalism, we compute a(u) over the entire domain 0<u<1/3. We find that a(u) diverges at the light-ring as ~0.25 (1-3u)^{-1/2}, explain the physical origin of this divergence, and discuss its consequences for the EOB formalism. We construct accurate global analytic fits for a(u), valid on the entire domain 0<u<1/3 (and possibly beyond), and give accurate numerical estimates of the values of a(u) and its first 3 derivatives at the ISCO, as well as the O(\nu) shift in the ISCO frequency. In previous work we used GSF data on slightly eccentric orbits to compute a certain linear combination of a(u) and its first two derivatives, involving also the O(\nu) piece \bar d(u) of a second EOB radial potential {\bar D}(u,\nu). Combining these results with our present global analytic representation of a(u), we numerically compute {\bar d}(u)$ on the interval 0<u\leq 1/6.Comment: 44 pages, 8 figures. Extended discussion in Section V and minor typographical corrections throughout. Version to be published in PR

Corporate Branding in SMEs: Concepts and Challenges

Bu araştırmada KOBİ’lerin kurumsal marka kavramını nasıl tanımlandığı, kurumsal marka sahibi olmalarının önündeki engeller ve KOBİ’lerde marka anlayışı keşfedilmeye çalışılmıştır. Kurumsal marka sahibi olmanın işletmeler için rekabet avantajı sağladığı ve birçok pazar avantajını beraberinde getirdiği literatürde vurgulanmıştır. Ancak, literatürdeki kurumsal marka araştırmalarının büyük işletmelere odaklandığı ve KOBİ'leri göz ardı ettiği görülmüştür. KOBİ'lerin dünya genelinde önemli bir ekonomik rol oynadığı göz önüne alındığında kurumsal marka oluşturmanın onlar için de uzun vadede faydalar saylayacağı öngörüldü. Bu nedenle, bu çalışmanın amacı KOBİ'lerin kurumsal marka oluşturmasını daha iyi anlamak ve literatürdeki bu boşluğu doldurmaktır. Araştırmadan elde edilen bulgulara göre KOBİ'lerde kurumsal markayı tanımlama ve geliştirmede işletme sahipleri ve yöneticilerinin rolünün büyük olduğunu ve bu kişilerin karakterinin kurumsal kültür ve kurumsal kimliği üzerinde etkili olduğunu ortaya çıkmıştır. Çalışma Türkiye'nin Kayseri şehrinde farklı sektörlerden 15 KOBİ sahibi veya yöneticisi ile yarı yapılandırılmış mülakatlar kullanarak gerçekleştirilmiştir. Veriler tematik analiz yöntemi ile incelenmiş ve beş ana tema belirlenmiştir: kurumsal marka kavramı, girişimci markası, ürün/hizmet markası, kurumsal marka sahibi olmanın önündeki engeller ve başarı. Sonuç olarak, bu araştırma KOBİ'lerin kurumsal marka oluşturmasının önemini ve işletme sahipleri/yöneticilerinin bu süreçteki kilit rolünü vurgulamaktadır. Bu çalışmanın KOBİ'ler için kurumsal marka oluşturma sürecini daha iyi anlamak ve geliştirmek isteyen işletmelere rehberlik edebileceği düşünülmektedir.EXTENDED ABSTRACT. Background & Purpose: The existing literature emphasizes the significance of establishing a distinctive corporate brand for achieving sustainable competitive advantages in business (Balmer, 2013; Brexendorf and Keller, 2017; Harris and de Chernatony, 2001). A well-developed corporate brand is a vital intangible asset within a company's portfolio (Biraghi and Gambetti, 2015; de Chernatony, 1999), offering various market advantages such as improved visibility, customer appeal, product support, visual distinctiveness, investor confidence, embodiment of organizational values, and workforce motivation (Balmer and Gray, 2003, p.973). Moreover, corporate branding acts as a strategic tool enabling firms, irrespective of their size, age, or industry, to secure a more effective market position and differentiate themselves from competitors (Hatch and Schultz, 2008). Notably, the benefits of corporate branding extend beyond large multinational corporations, as small and medium-sized enterprises (SMEs) can also leverage it to attain strategic advantages, including sales growth (M'zungu et al., 2019). However, most research in corporate branding has predominantly concentrated on large or multinational companies (Balmer, 2012; Krake, 2005), often overlooking SMEs (Centeno et al., 2013; Rode and Vallester, 2005; Wong and Merrilees, 2005). Given that SMEs constitute nearly 95% of global businesses and contribute around 60% to 70% of employment in OECD economies, they represent a significant segment that demands attention (OECD, 2018). Similar to large multinational corporations, SMEs benefit significantly from a robust corporate brand, allowing them to effectively communicate with both internal and external stakeholders, thereby enhancing their ability to create value (Nielsen and Thomsen, 2009; Gabrielli and Balboni, 2010). Regardless of their size, the creation, development, and maintenance of strong brands are imperative for gaining a competitive edge in the market (Hoeffler and Keller, 2003; Ojasalo et al., 2008). Nonetheless, experts in SME branding widely agree that the exploration of (corporate) branding at the SME level is limited and under-researched (Horan vd., 2011; M’zungu et al., 2019; Inskip, 2004). While some researchers, like Keller and Swaminathan (2015), argue that (corporate) branding is not a priority for SMEs, a substantial body of scientific literature underscores its significance and necessity within SMEs (Krake, 2005; Wong and Merrilees, 2005; Agostini et al., 2015; Centeno et al., 2013; Berthon et al., 2008). Krake's (2005) study in the Netherlands, utilizing the funnel model and interviews, explored branding in SMEs. The funnel model suggests that SME brand management is chiefly influenced by owner/manager experiences, creativity, and knowledge, with these individuals primarily making brand decisions, thereby establishing a strong link between SME manager/owner traits and brand identity, corporate culture, and organizational identity (Krake, 2005). Additionally, research by Spence and Hamzaoui Essoussi (2010) and Ojasalo et al. (2008) underscores the significant role of managers and owners in SME branding. Consequently, when examining brand concepts in SMEs, it's evident that the character of the business owner or manager is the primary factor shaping brand identity, corporate culture, and organizational identity (Rode and Vallaster, 2005; Boyle, 2003; Krake, 2005). Similarly, Rodeand Vallaster (2005) examined corporate branding in eight newly established German SMEs, discovering that entrepreneurs significantly influence employee behaviours aligned with corporate branding. Berthon et al. (2008) conducted a survey among 263 SMEs in the business-to-consumer (B2C) services sector, revealing disparities in brand management perceptions between SMEs and larger enterprises. Most studies examining branding in SMEs have primarily been conducted in developed countries. Furthermore, despite providing valuable insights, the process of corporate branding in SMEs remains inadequately explored. Therefore, this research aims to address this gap in the literature by conceptualizing corporate branding in SMEs and addressing the following research questions: How do SME managers and/or owners in developing countries define corporate branding? What are the barriers to the development of corporate branding in small and medium-sized enterprises (SMEs)? Research Method: To achieve these research objectives, 15 semi-structured interviews were conducted with SME owners/managers from various sectors in Kayseri, Turkey. This approach aimed to encourage diversity between groups while maintaining a certain level of homogeneity. These participants were chosen for their roles as internal stakeholders and their close relationships with other stakeholders. As suggested by Spence (1999), SME owners and managers maintain close relationships with the business's stakeholders. The initial participant was contacted through the researcher's network, and this participant subsequently recommended another person for the study, leading to a chain reaction where each participant recommended a new participant for the interviews. Thus, snowball sampling was employed to collect the necessary qualitative data for this study. Snowball sampling is frequently used in research on cultures where individual communication networks are crucial (Coleman, 1958). In this study, Interview questions were developed based on the literature, research philosophy, and methodology. The interviews were conducted face-to-face in Turkish. Due to political sensitivities in Turkey, all SME owners/managers were reluctant to allow audio recordings, so handwritten notes were taken for all interviews. Interviews were concluded when data saturation was reached, defined as no new data, codes, or themes emerging during interviews (Guest et al., 2006). Demographic information about the participants is summarized in Table 1. In accordance with the ethical guidelines from Brunel University, consent forms (refer to Appendices 1 for the Consent Form) were provided to all participants before each interview. Initial interviews were conducted with SME owners and managers, and notes were taken during these interviews to collect data. Subsequently, these notes were transcribed and integrated into the NVivo 11 software program for analysis. Throughout this study, the personal and company names of all interview participants were anonymized. Conclusion: The research identified five key themes in explaining the corporate branding concept in SMEs: corporate brand concept, entrepreneurial brand, product/service brand, barriers to becoming a corporate brand owner, and success. Although the majority of corporate branding research has centered on large or multinational companies, this study contributes to the literature by shedding light on the underexplored realm of corporate branding in SMEs. Understanding how SMEs conceptualize and navigate corporate branding provides valuable insights into this crucial aspect of business management

Variational Principles for Multiwalled Carbon Nanotubes Undergoing Vibrations Based on Nonlocal Timoshenko Beam Theory

Variational principles are derived for multiwalled carbon nanotubes undergoing linear vibrations using the semi-inverse method with the governing equations based on nonlocal Timoshenko beam theory which takes small scale effects and shear deformation into account. Physical models based on the nonlocal theory approximate the nanoscale phenomenon more accurately than the local theories by taking small scale phenomenon into account. Variational formulation is used to derive the natural and geometric boundary conditions which give a set of coupled boundary conditions in the case of free boundaries which become uncoupled in the case of the local theory. Hamilton's principle applicable to this case is also given

Area Invariance of Apparent Horizons under Arbitrary Boosts

It is a well known analytic result in general relativity that the 2-dimensional area of the apparent horizon of a black hole remains invariant regardless of the motion of the observer, and in fact is independent of the $t=constant$ slice, which can be quite arbitrary in general relativity. Nonetheless the explicit computation of horizon area is often substantially more difficult in some frames (complicated by the coordinate form of the metric), than in other frames. Here we give an explicit demonstration for very restricted metric forms of (Schwarzschild and Kerr) vacuum black holes. In the Kerr-Schild coordinate expression for these spacetimes they have an explicit Lorentz-invariant form. We consider {\it boosted} versions with the black hole moving through the coordinate system. Since these are stationary black hole spacetimes, the apparent horizons are two dimensional cross sections of their event horizons, so we compute the areas of apparent horizons in the boosted space with (boosted) $t = constant$, and obtain the same result as in the unboosted case. Note that while the invariance of area is generic, we deal only with black holes in the Kerr-Schild form, and consider only one particularly simple change of slicing which amounts to a boost. Even with these restrictions we find that the results illuminate the physics of the horizon as a null surface and provide a useful pedagogical tool. As far as we can determine, this is the first explicit calculation of this type demonstrating the area invariance of horizons. Further, these calculations are directly relevant to transformations that arise in computational representation of moving black holes. We present an application of this result to initial data for boosted black holes.Comment: 19 pages, 3 figures. Added a new section and 2 plots along with a coautho

Spin–orbit precession for eccentric black hole binaries at first order in the mass ratio

We consider spin–orbit ('geodetic') precession for a compact binary in strong-field gravity. Specifically, we compute ψ, the ratio of the accumulated spin-precession and orbital angles over one radial period, for a spinning compact body of mass m 1 and spin s 1, with ${{s}_{1}}\ll Gm_{1}^{2}/c$ , orbiting a non-rotating black hole. We show that ψ can be computed for eccentric orbits in both the gravitational self-force and post-Newtonian frameworks, and that the results appear to be consistent. We present a post-Newtonian expansion for ψ at next-to-next-to-leading order, and a Lorenz-gauge gravitational self-force calculation for ψ at first order in the mass ratio. The latter provides new numerical data in the strong-field regime to inform the effective one-body model of the gravitational two-body problem. We conclude that ψ complements the Detweiler redshift z as a key invariant quantity characterizing eccentric orbits in the gravitational two-body problem

Lot quality survey: an appealing method for rapid evaluation of vaccine coverage in developing countries – experience in Turkey

<p>Abstract</p> <p>Background</p> <p>Vaccine-preventable diseases cause significant morbidity and mortality worldwide and in developing countries in particular. Information on coverage and reasons for non-vaccination is vital to enhance overall vaccination activities. Of the several survey techniques available for investigating vaccination coverage in a given setting, the Lot Quality Technique (LQT) remains appealing and could be used in developing countries by local health personnel of district or rural health authorities to evaluate their performance in vaccination and many other health-related programs. This study aimed to evaluate vaccination coverage using LQT in a selected semi-urban setting in Turkey.</p> <p>Methods</p> <p>A LQT-based cross-sectional study was conducted in Kecioren District on a representative sample of residents aged 12–23 months in order to evaluate coverage for routine childhood vaccines, to identify health units with coverage below 75%, and to investigate reasons for non-vaccination.</p> <p>Results</p> <p>Based on self-reports, coverage for BCG, diphtheria-pertussis-tetanus (DPT-3), oral polio-3, hepatitis-3, and measles vaccines ranged between 94–99%. Coverage for measles was below 75% in five lots. The relatively high educational and socioeconomic status of parents in the study group alone could not minimize the "considerable" risk of vaccine-preventable diseases in the District and dictates a continuity of efforts for improving vaccination rates, with special emphasis on measles. We believe that administrative methods should be backed up by household surveys to strengthen vaccination monitoring and that families should be trained and motivated to have their children fully vaccinated according to the recommended schedule and in a timely manner.</p> <p>Conclusion</p> <p>This study identified vaccine coverage for seven routine vaccines completed before the age of 24 months as well as the areas requiring special attention in vaccination services. The LQT, years after its introduction to health-related research, remains an appealing technique for rapid evaluation of the extent of a variety of local health concerns in developing countries, in rural areas in particular, and is very efficient in determining performance of individual subunits in a given service area. Training of local health personnel on use of the LQT could expedite response to local health problems and could even motivate them in conducting their own surveys tailored to their professional interests.</p

Synergistic cooperation and crosstalk betweenMYD88L265Pand mutations that dysregulate CD79B and surface IgM

CD79B andMYD88mutations are frequently and simultaneously detected in B cell malignancies. It is not known if these mutations cooperate or how crosstalk occurs. Here we analyze the consequences ofCD79BandMYD88L265Pmutations individually and combined in normal activated mouse B lymphocytes.CD79Bmutations alone increased surface IgM but did not enhance B cell survival, proliferation, or altered NF-κB responsive markers. Conversely, B cells expressingMYD88L265Pdecreased surface IgM coupled with accumulation of endoglycosidase H-sensitive IgM intracellularly, resembling the trafficking block in anergic B cells repeatedly stimulated by self-antigen. Mutation or overexpression of CD79B counteracted the effect ofMYD88L265PIn B cells chronically stimulated by self-antigen,CD79BandMYD88L265Pmutations in combination, but not individually, blocked peripheral deletion and triggered differentiation into autoantibody secreting plasmablasts. These results reveal that CD79B and surface IgM constitute a rate-limiting checkpoint against B cell dysregulation byMYD88L265Pand provide an explanation for the co-occurrence ofMYD88andCD79Bmutations in lymphomas

Analysis of in vitro bioactivity data extracted from drug discovery literature and patents: Ranking 1654 human protein targets by assayed compounds and molecular scaffolds

<p>Abstract</p> <p>Background</p> <p>Since the classic Hopkins and Groom druggable genome review in 2002, there have been a number of publications updating both the hypothetical and successful human drug target statistics. However, listings of research targets that define the area between these two extremes are sparse because of the challenges of collating published information at the necessary scale. We have addressed this by interrogating databases, populated by expert curation, of bioactivity data extracted from patents and journal papers over the last 30 years.</p> <p>Results</p> <p>From a subset of just over 27,000 documents we have extracted a set of compound-to-target relationships for biochemical <it>in vitro </it>binding-type assay data for 1,736 human proteins and 1,654 gene identifiers. These are linked to 1,671,951 compound records derived from 823,179 unique chemical structures. The distribution showed a compounds-per-target average of 964 with a maximum of 42,869 (Factor Xa). The list includes non-targets, failed targets and cross-screening targets. The top-278 most actively pursued targets cover 90% of the compounds. We further investigated target ranking by determining the number of molecular frameworks and scaffolds. These were compared to the compound counts as alternative measures of chemical diversity on a per-target basis.</p> <p>Conclusions</p> <p>The compounds-per-protein listing generated in this work (provided as a supplementary file) represents the major proportion of the human drug target landscape defined by published data. We supplemented the simple ranking by the number of compounds assayed with additional rankings by molecular topology. These showed significant differences and provide complementary assessments of chemical tractability.</p

Severe Neuro-COVID is associated with peripheral immune signatures, autoimmunity and neurodegeneration: a prospective cross-sectional study

Growing evidence links COVID-19 with acute and long-term neurological dysfunction. However, the pathophysiological mechanisms resulting in central nervous system involvement remain unclear, posing both diagnostic and therapeutic challenges. Here we show outcomes of a cross-sectional clinical study (NCT04472013) including clinical and imaging data and corresponding multidimensional characterization of immune mediators in the cerebrospinal fluid (CSF) and plasma of patients belonging to different Neuro-COVID severity classes. The most prominent signs of severe Neuro-COVID are blood-brain barrier (BBB) impairment, elevated microglia activation markers and a polyclonal B cell response targeting self-antigens and non-self-antigens. COVID-19 patients show decreased regional brain volumes associating with specific CSF parameters, however, COVID-19 patients characterized by plasma cytokine storm are presenting with a non-inflammatory CSF profile. Post-acute COVID-19 syndrome strongly associates with a distinctive set of CSF and plasma mediators. Collectively, we identify several potentially actionable targets to prevent or intervene with the neurological consequences of SARS-CoV-2 infection