Insights into the activation mechanism of PopA, a cyclic di-GMP effector protein involved in cell cycle and development of "Caulobacter Crescentus"

In Caulobacter crescentus, a complex network integrating cyclic di-GMP and Phosphorylation-dependent signals controls the proteolysis of key regulatory proteins to drive cell cycle and polar morphogenesis. The c-di-GMP input is processed by the effector protein PopA. Upon binding of c-di-GMP, PopA is sequestered to the old cell pole where it recruits the replication and cell division inhibitors CtrA and KidO and mediates their destruction by the polar ClpXP protease prior to entry into S-phase. In addition to its role at the stalked cell pole, PopA localizes to the opposite cell pole in dependence of the general topology factor PodJ where it exerts a yet unknown function. Here we address the activation and polar sequestration mechanism of PopA guided by an existing activation model for the highly homologous c-di-GMP signaling protein PleD. PopA and PleD do not only share an identical domain organization (Rec1-Rec2-GGDEF), but also show similar spatio-temporal behavior during the cell cycle. While PleD is activated and targeted to the old cell pole via phosphorylation-induced dimerization, we show that PopA stalked pole function is phosphorylation-independent and requires c-di-GMP binding as a primary input signal for activation and polar localization. c-di-GMP binds to conserved primary and secondary I-sites within the PopA GGDEF domain and we show that intact binding sites are required for PopA positioning and function. This suggests that c-di-GMP-dependent crosslinking of adjacent GGDEF domains contributes to the localization of an active PopA dimer to the cell pole. Consistent with this, we demonstrate that the GGDEF domain encodes the polar localization signal(s), while the N-terminal receiver domains serve as interaction platform for downstream components that are actively recruited by PopA. Among these downstream factors is RcdA, a small mediator protein that interacts with the first PopA receiver domain and helps to recruit and degrade CtrA and KidO. In a screen for additional components of the PopA pathway we identify two novel proteins that directly interact with PopA, CC1462 and CC2616. CC1462 is a ClpXP substrate that requires PopA for polar positioning and subsequent degradation during swarmer-to-stalked cell transition. Although located in a flagellar gene cluster, deletion of CC1462 did not affect flagellar assembly and function. Its cellular role as well as the significance of its cell cycle-dependent degradation requires further studies. CC2616, the second PopA interaction partner, is not proteolytically processed and thus belongs to another class of PopA-dependent substrates. CC2616 is annotated as guanine deaminase, which is predicted to catalyze the conversion from guanine to xanthine thereby irreversibly removing guanine based nucleotides from a cellular pool. A CC2616 deletion leads to increased attachment and decreased motility, a phenocopy of strains with elevated c-di-GMP levels. It is not clear whether CC2616 indeed has deaminase activity or whether it has adopted a novel function. Taken together, this work provides insight into the activation mechanism of a c-di-GMP effector protein. We propose that PopA has evolved through gene duplication from its ancestor, the catalytic PleD response regulator but has lost catalytic activity of the diguanylate cyclase domain. Moreover, PopA has adopted an inverse intra-molecular information transfer originating through c-di-GMP binding at the C-terminal GGDEF domain, which in turn activates the N-terminal receiver stem to serve as platform for downstream partner recruitment

Dançar com Histórias: Uma Tática Pedagógica Inventiva

At the intersection of art and teacher training, creative spaces emerge for new pedagogical practices and new perspectives on oneself and on the teaching profession. This text is a reflection based on a formative meeting with early childhood education teachers in the city of São Paulo in which two artistic languages ​​were crossed, namely dance and storytelling, promoting new perspectives for the work developed with students and the students of those teachers and themselves. It is a possibility of work, not to be followed as a model, but as an opening of other ways of teaching, dialoguing with the proposal of inventive formation. It is in the blurring of the borders between artistic languages, in a new territory – the school – that this text will develop, crying out for a ‘play’, in search of a becoming-child. Our bet is that this deterritorialization moves thinking, opening space for other pedagogical practices less linked to standards of right and wrong, but something more transgressive, provocative and above all inventive.En la intersección del arte y la formación docente surgen espacios creativos para nuevas prácticas pedagógicas y nuevas miradas sobre uno mismo y sobre la profesión docente. Este texto es una reflexión a partir de un encuentro formativo con docentes de educación infantil de la ciudad de São Paulo en el que se cruzaron dos lenguajes artísticos, a saber, la danza y la narración de cuentos, promoviendo nuevas perspectivas para el trabajo desarrollado con los alumnos y las alumnas de esas maestros y ellos mismos. Es una posibilidad de trabajo, no para ser seguido como modelo, sino como apertura de otras formas de enseñar, dialogando con la propuesta de formación inventiva. Es en el desdibujamiento de las fronteras entre los lenguajes artísticos, en un nuevo territorio – la escuela – que se desarrollará este texto, llamando a una ‘obra’, en busca de un devenir-niño. Nuestra apuesta es que esta desterritorialización mueva el pensamiento, abriendo espacio para otras prácticas pedagógicas menos ligadas a estándares del bien y del mal, pero algo más transgresoras, provocadoras y sobre todo inventivas.No cruzamento da arte com a formação de professores emergem espaços criativos para novas práticas pedagógicas e novas lentes perspectivas sobre si mesmo e sobre o oficio docente. Este texto é uma reflexão a partir de um encontro formativo com professoras de educação infantil da cidade de São Paulo em que duas linguagens artísticas foram cruzadas, a saber a dança e a contação de histórias, promovendo novos olhares para o trabalho desenvolvido com os alunos e as alunas daquelas professoras e delas mesmas. Trata-se de uma possibilidade de trabalho, não para ser seguido como modelo, mas como abertura de outras formas de ensinar, dialogando com a proposta de formação inventiva. É no borrão das fronteiras entre linguagens artísticas, em um novo território – a escola – que este texto irá se desenvolver, clamando por um ‘brincar’, em busca de um devir-criança. Nossa aposta é que esta desterritorialização movimenta o pensar abrindo espaço para outras práticas pedagógicas menos vinculadas a padrões de certo e errado, mas algo mais transgressor, provocador e acima de tudo inventivo

Grundversorgung: Der Weg aus der Krise führt auch über die MPA

Die meisten Hausärzte und Hausärztinnen in der Schweiz sind dauerhaft überlastet. Um zusätzliche Kapazitäten zu schaffen, sind ihre Leistungen auf mehr Schultern zu verteilen und die Betreuung im (Praxis-)Team zu verstärken. Besonders dafür geeignet ist die Begleitung von chronisch kranken Patienten durch die Medizinische Praxisassistentin. Das Problem: Der Arzt kann diese Leistungen nicht abrechnen. Dies ist so rasch wie möglich zu ändern, damit die MPA endlich den Wert erhält, den sie längst verdient

Bhabha scattering at NNLO with next-to-soft stabilisation

A critical subject in fully differential QED calculations originates from numerical instabilities due to small fermion masses that act as regulators of collinear singularities. At next-to-next-to-leading order (NNLO) a major challenge is therefore to find a stable implementation of numerically delicate real-virtual matrix elements. In the case of Bhabha scattering this has so far prevented the development of a fixed-order Monte Carlo at NNLO accuracy. In this paper we present a new method for stabilising the real-virtual matrix element. It is based on the expansion for soft photon energies including the non-universal subleading term calculated with the method of regions. We have applied this method to Bhabha scattering to obtain a stable and efficient implementation within the McMule framework. We therefore present for the first time fully differential results for the photonic NNLO corrections to Bhabha scattering

Møller scattering at NNLO

We present a calculation of the full set of next-to-next-to-leading-order QED corrections to unpolarized Møller scattering. This encompasses photonic, leptonic, and nonperturbative hadronic corrections and includes electron mass effects as well as hard photon radiation. The corresponding matrix elements are implemented in the Monte Carlo framework mcmule allowing for the computation of fully differential observables. As a first application we show results tailored to the kinematics and detector design of the PRad II experiment where a high-precision theory prediction for Møller scattering is required to achieve the targeted precision. We observe that the corrections become essential to reliably calculate the corresponding differential distributions especially in regions where the leading-order contribution is absent

Analysis of Manufacturing Methods and Die Design for Agricultural Parts in Bangladesh

The adoption of agricultural mechanization in Bangladesh has risen over the past decade with increased usage of combine harvesters, rice transplanters, and other farming implements. Due to this, a market has developed for small machine shops to manufacture spare parts within the local communities. This thesis analyzes OEM parts and devises multiple manufacturing methods that can be implemented by small machine shops to fabricate the following two parts: combine harvester blades and rice transplanter pickup forks. First, the OEM parts are tested for material composition and hardness so that similar metals can be found in Bangladesh. Then, a range of manufacturing processes are analyzed and compared to find the most effective manufacturing methods that balance the labor cost, capital equipment cost, and production volume, commonly found in Bangladesh. The most basic manufacturing processes analyzed to create the product using highly manual and labor-intensive activities that involve very little upfront investment and high levels of personal workmanship. The most advanced manufacturing process incorporates mechanical and hydraulic presses to form all complex part features.M.S

Slobodni smo

The centromere is essential for the segregation of chromosomes, as it serves as attachment site for microtubules to mediate chromosome segregation during mitosis and meiosis. In most organisms, the centromere is restricted to one chromosomal region that appears as primary constriction on the condensed chromosome and is partitioned into two chromatin domains: The centromere core is characterized by the centromere-specific histone H3 variant CENP-A (also called cenH3) and is required for specifying the centromere and for building the kinetochore complex during mitosis. This core region is generally flanked by pericentric heterochromatin, characterized by nucleosomes containing H3 methylated on lysine 9 (H3K9me) that are bound by heterochromatin proteins. During mitosis, these two domains together form a three-dimensional structure that exposes CENP-A-containing chromatin to the surface for interaction with the kinetochore and microtubules. At the same time, this structure supports the tension generated during the segregation of sister chromatids to opposite poles. In this review, we discuss recent insight into the characteristics of the centromere, from the specialized chromatin structures at the centromere core and the pericentromere to the three-dimensional organization of these regions that make up the functional centromere

Selênio em bovinos leiteiros do estado de São Paulo. IV. Suplementação de selênio “ad libitum” na mistura de sal

Twenty crossbred dry cows were used to test selenium supplementation in salt mixtures ingested “ad libitum” in pasture. Average daily intake of salt mixture was 25 g per cow which is equivalent to a selenium consumption of 1.1 g (as sodium selenite). Treated cows showed significantly (p ≤0.01) higher serum selenium levels than control unsupplemented cows.Vinte vacas cruzadas, secas, foram utilizadas para observações sobre ingestão de Selênio na mistura de sal, consumida “ad libitum”, em cocho colocado no pasto. O consumo médio diário da mistura foi igual a 25 gramas por vaca, nas quais estava incluída 1,1 mg de Selênio (como selenito de sódio). As vacas suplementadas apresentaram níveis séricos de Selênio significativamente (p < 0,01) mais elevados que as parceiras não suplementadas

Efeito da suplementação com aditivos nutricionais sobre características de crescimento de bovinos da raça Nelore em Testes de Desempenho de Touros Jovens.

Objetivou-se com este estudo avaliar o efeito da suplementação, com diferentes tipos de aditivos, sobre características de crescimento de bovinos da raça Nelore em Testes de Desempenho de Touros Jovens. Foram avaliadas três provas de ganho em peso (PGP 1, PGP 2 e PGP 3). Em cada PGP, foi utilizado um aditivo diferente, tanto no período da seca quanto das águas. Dessa forma, os aditivos utilizados foram: PGP 1, monensina sódica; PGP 2, probiótico; e, PGP 3, virginiamicina. O valor genético dos animais foi predito pelo método da máxima verossimilhança restrita, o qual foi subtraído de sua respectiva pesagem, de forma que todos os animais apresentassem valor genético igual à zero. As análises de dados longitudinais foram realizadas utilizando o método de medidas repetidas no tempo. Os animais suplementados com monensina sódica e virginiamicina apresentaram os maiores pesos médios. Entretanto, os animais alimentados com o aditivo virginiamicina no suplemento, apresentaram maior velocidade de crescimento e desenvolvimento. Portanto, a utilização de virginiamicina promoveu incrementos positivos tanto no peso quando ganho em peso diário dos animais participantes dos Testes de Desempenho de Touros Jovens