葡萄牙松材线虫与其媒介昆虫之间的互作Pedro Miguel Naves, Luís Bonifácio, Edmundo Sousa

对松材线虫与其在葡萄牙和欧洲的媒介昆虫樟子松墨天牛（Monochamus galloprovincialis）进行了首次研究。在病死木中发现,松材线虫在天牛刚羽化时聚集在蛹室中,线虫主要集中在天牛的后胸部。天牛羽化后6周内,松材线虫主要在天牛成虫补充营养时进入新寄主树,其次在天牛产卵时也会进入寄主树。总的看来,松材线虫在欧洲与其携带天牛之间互作与其在亚洲与松墨天牛及在北美与卡来罗纳墨天牛之间的关系十分相似。经研究,影响线虫与天牛携带关系的因子有内源和外源两类因子,如化学气味和各种信号。但是,其他多数因子尚未了解。研究影响线虫与天牛携带关系的因子将有助于了解两种生物密切关系的内在机制,并有助于研发出新的防控方法。     

How incoherent measurement succeeds: Coordination and success in the measurement of the earth's polar flattening

The development of nineteenth-century geodetic measurement challenges the dominant coherentist account of metric success. Coherentists argue that measurements of a parameter are successful if their numerical outcomes convergence across varying contextual constraints. Aiming at numerical convergence, in turn, offers an operational aim for scientists to solve problems of coordination. Geodesists faced such a problem of coordination between two indicators of the earth's polar flattening, which were both based on imperfect ellipsoid models. While not achieving numerical convergence, their measurements produced novel data that grounded valuable theoretical hypotheses. Consequently, they ought to be regarded as epistemically successful. This insight warrants a dynamic revision of coherentism, which allows to judge the success of a metric based on both its coherence and fruitfulness. On that view, scientific measurement aims to coordinate theoretical definitions and produce novel data and theoretical insights.     

System Dynamics and Learning Scenarios for Process Improvement and Regional Resilience: A Study in The Footwear Industry of Southern Brazil

Systemic Practice and Action Research - By means of integrated and systemic resilience strategies, it is possible to reduce vulnerability and risk, and at the same time increase the capacity to...     

A Systemic Framework to Develop Sustainable Engineering Solutions in Rural Communities in Colombia

In several rural areas in Colombia there is a serious lack of water quality supply. Thereby the problematic situation is understood as complex one that involves stakeholders with pluralistic interests, multiple variables and requires the development of sustainable and suitable solutions. In order to address this issue, this paper proposes an integration of engineering design framework (CDIO) with a systemic approach. Particularly the approach emphasizes on systemic elements such as autonomy, systems within systems, cooperation between stakeholders and cause effect relations; it also proposes a previous observing phase for engineering design framework. Thus the proposed systemic framework aims to generate projects that improve living conditions in rural communities and promote the production of knowledge between the stakeholders to ensure sustainability in the long term. To illustrate the proposal, this work contains a case study that discusses a project carried out by a research team—Ingenieros Sin Fronteras Colombia—in a rural district near to Colombia’s capital. The experience, which involved and benefited 16 families in the community, provided strong evidence to support the proposed framework. The paper concludes with a discussion about the replication of this proposal in other contexts.     

A Computational Model of the Belief System Under the Scope of Social Communication

This paper presents an approach to the belief system based on a computational framework in three levels: first, the logic level with the definition of binary local rules, second, the arithmetic level with the definition of recursive functions and finally the behavioural level with the definition of a recursive construction pattern. Social communication is achieved when different beliefs are expressed, modified, propagated and shared through social nets. This approach is useful to mimic the belief system because the defined functions provide different ways to process the same incoming information as well as a means to propagate it. Our model also provides a means to cross different beliefs so, any incoming information can be processed many times by the same or different functions as it occurs is social nets.     

Early microbiota,antibiotics and health

The colonization of the neonatal digestive tract provides a microbial stimulus required for an adequate maturation towards the physiological homeostasis of the host. This colonization, which is affected by several factors, begins with facultative anaerobes and continues with anaerobic genera. Accumulating evidence underlines the key role of the early neonatal period for this microbiota-induced maturation, being a key determinant factor for later health. Therefore, understanding the factors that determine the establishment of the microbiota in the infant is of critical importance. Exposure to antibiotics, either prenatally or postnatally, is common in early life mainly due to the use of intrapartum prophylaxis or to the administration of antibiotics in C-section deliveries. However, we are still far from understanding the impact of early antibiotics and their long-term effects. Increased risk of non-communicable diseases, such as allergies or obesity, has been observed in individuals exposed to antibiotics during early infancy. Moreover, the impact of antibiotics on the establishment of the infant gut resistome, and on the role of the microbiota as a reservoir of resistance genes, should be evaluated in the context of the problems associated with the increasing number of antibiotic resistant pathogenic strains. In this article, we review and discuss the above-mentioned issues with the aim of encouraging debate on the actions needed for understanding the impact of early life antibiotics upon human microbiota and health and for developing strategies aimed at minimizing this impact.     

Distant metastasis occurs late during the genetic evolution of pancreatic cancer

Metastasis, the dissemination and growth of neoplastic cells in an organ distinct from that in which they originated, is the most common cause of death in cancer patients. This is particularly true for pancreatic cancers, where most patients are diagnosed with metastatic disease and few show a sustained response to chemotherapy or radiation therapy. Whether the dismal prognosis of patients with pancreatic cancer compared to patients with other types of cancer is a result of late diagnosis or early dissemination of disease to distant organs is not known. Here we rely on data generated by sequencing the genomes of seven pancreatic cancer metastases to evaluate the clonal relationships among primary and metastatic cancers. We find that clonal populations that give rise to distant metastases are represented within the primary carcinoma, but these clones are genetically evolved from the original parental, non-metastatic clone. Thus, genetic heterogeneity of metastases reflects that within the primary carcinoma. A quantitative analysis of the timing of the genetic evolution of pancreatic cancer was performed, indicating at least a decade between the occurrence of the initiating mutation and the birth of the parental, non-metastatic founder cell. At least five more years are required for the acquisition of metastatic ability and patients die an average of two years thereafter. These data provide novel insights into the genetic features underlying pancreatic cancer progression and define a broad time window of opportunity for early detection to prevent deaths from metastatic disease.     

Structural basis for gene regulation by a thiamine pyrophosphate-sensing riboswitch

Riboswitches are metabolite-sensing RNAs, typically located in the non-coding portions of messenger RNAs, that control the synthesis of metabolite-related proteins. Here we describe a 2.05 angstroms crystal structure of a riboswitch domain from the Escherichia coli thiM mRNA that responds to the coenzyme thiamine pyrophosphate (TPP). TPP is an active form of vitamin B1, an essential participant in many protein-catalysed reactions. Organisms from all three domains of life, including bacteria, plants and fungi, use TPP-sensing riboswitches to control genes responsible for importing or synthesizing thiamine and its phosphorylated derivatives, making this riboswitch class the most widely distributed member of the metabolite-sensing RNA regulatory system. The structure reveals a complex folded RNA in which one subdomain forms an intercalation pocket for the 4-amino-5-hydroxymethyl-2-methylpyrimidine moiety of TPP, whereas another subdomain forms a wider pocket that uses bivalent metal ions and water molecules to make bridging contacts to the pyrophosphate moiety of the ligand. The two pockets are positioned to function as a molecular measuring device that recognizes TPP in an extended conformation. The central thiazole moiety is not recognized by the RNA, which explains why the antimicrobial compound pyrithiamine pyrophosphate targets this riboswitch and downregulates the expression of thiamine metabolic genes. Both the natural ligand and its drug-like analogue stabilize secondary and tertiary structure elements that are harnessed by the riboswitch to modulate the synthesis of the proteins coded by the mRNA. In addition, this structure provides insight into how folded RNAs can form precision binding pockets that rival those formed by protein genetic factors.