Q fever is a highly infectious disease with a worldwide distribution. Its causative agent, the intracellular bacterium Coxiella burnetii, infects a variety of vertebrate species, including humans. ...Its evolutionary origin remains almost entirely unknown and uncertainty persists regarding the identity and lifestyle of its ancestors. A few tick species were recently found to harbor maternally-inherited Coxiella-like organisms engaged in symbiotic interactions, but their relationships to the Q fever pathogen remain unclear. Here, we extensively sampled ticks, identifying new and atypical Coxiella strains from 40 of 58 examined species, and used this data to infer the evolutionary processes leading to the emergence of C. burnetii. Phylogenetic analyses of multi-locus typing and whole-genome sequencing data revealed that Coxiella-like organisms represent an ancient and monophyletic group allied to ticks. Remarkably, all known C. burnetii strains originate within this group and are the descendants of a Coxiella-like progenitor hosted by ticks. Using both colony-reared and field-collected gravid females, we further establish the presence of highly efficient maternal transmission of these Coxiella-like organisms in four examined tick species, a pattern coherent with an endosymbiotic lifestyle. Our laboratory culture assays also showed that these Coxiella-like organisms were not amenable to culture in the vertebrate cell environment, suggesting different metabolic requirements compared to C. burnetii. Altogether, this corpus of data demonstrates that C. burnetii recently evolved from an inherited symbiont of ticks which succeeded in infecting vertebrate cells, likely by the acquisition of novel virulence factors.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A
bstract
Achieving full moduli stabilisation in type IIB string compactifications for generic Calabi-Yau threefolds with hundreds of Kähler moduli is notoriously hard. This is due not just to the ...very fast increase of the computational complexity with the number of moduli, but also to the fact that the scalar potential depends in general on the supergravity variables only implicitly. In fact, the supergravity chiral coordinates are 4- cycle volume moduli but the Kähler potential is an explicit function of the 2-cycle moduli and inverting between these two variables is in general impossible. In this paper we pro- pose a general method to fix all type IIB Kähler moduli in a systematic way by working directly in terms of 2-cycle moduli: on one side we present a ‘master formula’ for the scalar potential which can depend on an arbitrary number of Kähler moduli, while on the other we perform a computer-based search for critical points, introducing a hybrid Genetic/Clustering/Amoeba algorithm and other computational techniques. This allows us to reproduce several known minima, but also to discover new examples of both KKLT and LVS models, together with novel classes of LVS minima without diagonal del Pezzo divisors and hybrid vacua which share some features with KKLT and other with LVS solutions.
Fundamental to all living organisms is the capacity to coordinate cell division and cell differentiation to generate appropriate numbers of specialized cells. Whereas eukaryotes use cyclins and ...cyclin-dependent kinases to balance division with cell fate decisions, equivalent regulatory systems have not been described in bacteria. Moreover, the mechanisms used by bacteria to tune division in line with developmental programs are poorly understood. Here we show that Caulobacter crescentus, a bacterium with an asymmetric division cycle, uses oscillating levels of the second messenger cyclic diguanylate (c-di-GMP) to drive its cell cycle. We demonstrate that c-di-GMP directly binds to the essential cell cycle kinase CckA to inhibit kinase activity and stimulate phosphatase activity. An upshift of c-di-GMP during the G1-S transition switches CckA from the kinase to the phosphatase mode, thereby allowing replication initiation and cell cycle progression. Finally, we show that during division, c-di-GMP imposes spatial control on CckA to install the replication asymmetry of future daughter cells. These studies reveal c-di-GMP to be a cyclin-like molecule in bacteria that coordinates chromosome replication with cell morphogenesis in Caulobacter. The observation that c-di-GMP-mediated control is conserved in the plant pathogen Agrobacterium tumefaciens suggests a general mechanism through which this global regulator of bacterial virulence and persistence coordinates behaviour and cell proliferation.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
We show that spontaneous baryogenesis occurs automatically in relaxion models if the reheating temperature is larger than the weak scale, provided the Standard Model fields are charged under the U(1) ...of which the relaxion is a pseudo-Nambu-Goldstone boson. During the slow roll, the relaxion breaks CPT, biasing the thermal equilibrium in favor of baryons, with sphalerons providing the necessary baryon number violation. We calculate the resulting baryon asymmetry, explore the possible constraints on this scheme and show that there is a swath of parameter space in which the current observations are matched. Successful baryogenesis can be achieved for a range of relaxion masses between 10−10 and 10−5 eV. The mechanism operates precisely in the region of parameter space where recent work has shown relaxion oscillations to be a dark matter candidate.
Rainwater Harvesting Systems (RHS) are increasingly used in buildings to mitigate water shortage and rising prices of centralised water supply. Notwithstanding the benefits of RHS, they may also ...promote adverse impacts mainly related to the high consumption of energy. In this context, energy intensity (i.e. unit of energy per unit of water) is a crucial parameter for assessing the environmental feasibility of different RHS. However, only recently has attention been drawn to the connection between water and energy consumption, which has been prompted by the increasing importance of water security, energy efficiency and economic feasibility. This connection, known as the water-energy nexus, has been increasingly acknowledged as a key principal for water planning. The objective of this study is twofold: (i) to review the energy intensity data reported for RHS; and (ii) to outline strategies to enhance the energy performance of RHS in buildings. For the reviewed literature, the median energy intensity of theoretical studies (0.20kWh/m³) was considerably lower than that described in empirical studies (1.40kWh/m³). This implies that theoretical assessments of energy intensity may not sufficiently consider the energy used for pump start-ups and standby mode, as well as the true motor and pump energy efficiency. However, to some extent, this difference may also represent the amount of energy that can be reduced by optimising RHS design and operation. When comparing RHS to conventional town water supply systems, the reviewed empirical studies showed that RHS tend to be three times more energy intensive, although optimised RHS can have more comparable values. Ultimately, it is predominately the local characteristics, such as rainwater demand, building type (single-storey or multi-storey), RHS sub-systems design, potable water plumbing system design, and town water energy intensity, among other factors that will determine whether or not the environmental and economic performances of RHS are acceptable.
•RHS are typically more energy intensive than conventional town water supply systems.•Theoretical studies significantly underestimate the energy intensity of RHS.•RHS pump stand-by and start-up power was rarely considered in reported theoretical studies.•Well-designed RHS have similar levels of energy intensity to town water supply.•The use of header tanks lowers the energy intensity of RHS.
Nonparametric multiple comparisons are a powerful statistical inference tool in psychological studies. In this paper, we review a rank-based nonparametric multiple contrast test procedure (MCTP) and ...propose an improvement by allowing the procedure to accommodate various effect sizes. In the review, we describe relative effects and show how utilizing the unweighted reference distribution in defining the relative effects in multiple samples may avoid the nontransitive paradoxes. Next, to improve the procedure, we allow the relative effects to be transformed by using the multivariate delta method and suggest a log odds-type transformation, which leads to effect sizes similar to Cohen’s
d
for easier interpretation. Then, we provide theoretical justifications for an asymptotic strong control of the family-wise error rate (FWER) of the proposed method. Finally, we illustrate its use with a simulation study and an example from a neuropsychological study. The proposed method is implemented in the ‘nparcomp’ R package via the ‘mctp’ function.
Aim
To explore the experiences of people recently diagnosed with prediabetes and overweight or obese in making dietary changes following a six‐month primary care nurse‐delivered dietary intervention ...pilot.
Methods
Semi‐structured interviews were conducted with 20 participants, purposefully selected to ensure a mix of ethnicity, gender and glycaemic outcome. Thematic analysis of interview data was undertaken.
Results
Participants described feeling shocked when they received the diagnosis of prediabetes. Three core themes, each containing subthemes, emerged: (i) supportive factors ‐ determination not to develop diabetes, clear information and manageable strategies, and supportive relationships; (ii) barriers ‐ lack of family support, financial constraints, social expectations around food, and chronic health issues; and (iii) overcoming challenges ‐ growing and sharing food, using frozen vegetables and planning. Challenges related to cultural expectations around providing and partaking of food were more evident for indigenous Māori participants.
Conclusions
A diagnosis of prediabetes provides a window of opportunity for healthcare professionals to work with those diagnosed and their families to make healthful dietary changes. Dietary guidance is likely to be most effective when individuals’ life circumstances are taken into account. Clear information and supportive relationships to facilitate lifestyle change are extremely important.
(Clinical Trials Registry No; ANZCTR ACTRN1261500080656)
What's new?
Well presented, clear dietary information and individualised manageable strategies within the context of supportive health professional and family relationships facilitate healthful dietary change in those with prediabetes.
Conversely, lack of family support, financial constraints, social expectations around food, and chronic health issues present barriers to dietary change.
Adoption of dietary recommendations for prediabetes is more likely to occur when guidance is tailored to individuals’ life circumstances, and advice provided around the time of diagnosis of prediabetes when the motivation to make changes appears high may be an ideal time.
Fifty Years of Artificial Reverberation Valimaki, V.; Parker, J. D.; Savioja, L. ...
IEEE transactions on audio, speech, and language processing,
07/2012, Letnik:
20, Številka:
5
Journal Article
Recenzirano
The first artificial reverberation algorithms were proposed in the early 1960s, and new, improved algorithms are published regularly. These algorithms have been widely used in music production since ...the 1970s, and now find applications in new fields, such as game audio. This overview article provides a unified review of the various approaches to digital artificial reverberation. The three main categories have been delay networks, convolution-based algorithms, and physical room models. Delay-network and convolution techniques have been competing in popularity in the music technology field, and are often employed to produce a desired perceptual or artistic effect. In applications including virtual reality, predictive acoustic modeling, and computer-aided design of acoustic spaces, accuracy is desired, and physical models have been mainly used, although, due to their computational complexity, they are currently mainly used for simplified geometries or to generate reverberation impulse responses for use with a convolution method. With the increase of computing power, all these approaches will be available in real time. A recent trend in audio technology is the emulation of analog artificial reverberation units, such as spring reverberators, using signal processing algorithms. As a case study we present an improved parametric model for a spring reverberation unit.
Africa and the ICC Clarke, Kamari M; Knottnerus, Abel S; Volder, Eefje De
04/2016
eBook
Africa and the ICC: Realities and Perceptions comprises contributions from prominent scholars of different disciplines including international law, political science, cultural anthropology, African ...history and media studies. This unique collection provides the reader with detailed insights into the interaction between the African Union and the International Criminal Court (ICC), but also looks further at the impact of the ICC at a societal level in African states and examines other justice mechanisms on a local and regional level in these countries. This investigation of the ICC's complicated relationship with Africa allows the reader to see that perceptions of justice are multilayered.
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