Temperature induced structural changes in even-odd nylons with long polymethylene segments

Structural transitions of nylons 8 9 and 12 9 heating and cooling processes were investigated using calorimetric, spectroscopic during and real time X-ray diffraction data. These even-odd nylons had three polymorphic forms related to structures where hydrogen bonds were established in two planar directions. Heating processes showed a first structural transition at low temperature where the two strong reflections related to the packing mode of the low temperature structure (form I) disappeared instead of moving together and merging into a single reflection, as observed for conventional even-even nylons. The high temperature structure corresponded to a typical pseudohexagonal packing (form III) attained after the named Brill transition temperature. Structural transitions were not completely reversible since an intermediate structure (form II) became clearly predominant at room temperature in subsequent cooling processes. A single spherulitic morphology with negative birefringence and a flat-on edge-on lamellar disposition was obtained when the two studied polyamides crystallized from the melt state. Kinetic analyses indicated that both nylons crystallized according to a single regime and a thermal nucleation. Results also pointed out a secondary nucleation constant for nylon 12 9 higher than that for nylon 8 9, suggesting greater difficulty in crystallizing when the amide content decreased. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 2494–2506Peer ReviewedPostprint (author's final draft

Overview of Study Areas and UNAM-Iztacala Student Research

The State of Veracruz is located on the east coast of Mexico and consists of many shallow marine systems such as estuaries and coastal lagoons. These estuarine systems are ecological sites of great importance due to the interactions that occur between the intertidal zones and adjacent areas. This importance is reflected in the variety of natural components present in these sites as well as the large number of species that depend on this aquatic zone, such as birds, mammals, molluscs, crustaceans and fishes. Many of the crustaceans and fishes are consumed by the local inhabitants and distributed in commercial areas in Mexico City. It is estimated that Veracruz state is in fourth place in fisheries landings for the country, and contributes 10% of the total fisheries production. Academic personnel from the laboratories of Ecology and Zoology in the Facultad de Estudios Superiores Iztacala, Tlalnapantla, Mexico have focused their research efforts since 1988 on two of the systems in Veracruz state, the Tecolutla River and the lagoonal system of Alvarado. Research in both locations has resulted in a number of professional theses by undergraduate students in the Biology Department at UNAM-Iztacala

Position practices of the present-day CFO: a reflection on historic roles at Guinness, 1920-1945

AbstractContemporary studies of Chief Financial Officers (CFO) paint a picture of the role pre-1960 as being reflective of a more transactional one. Historical research sheds some doubt on this, and tends not to separate the role from its occupier. We provide an analysis of such a role in a large brewery from about 1920 to 1945. Drawing on the concept of position-practices, our results suggest that a CFO-predecessor role was informed by existing position-practices, which are separately identifiable from the occupier of the role itself. Some of the position-practices are recognizable in contemporary CFO roles. Importantly, focusing on the role as opposed to the occupier, gives our study potential to more broadly inform future research on the contemporary role

Synonymous Codon Pair Recoding of the HIV-1 env Gene Affects Virus Replication Capacity

Synonymous codon pair deoptimization is an efficient strategy for virus attenuation; however, the underlying mechanism remains controversial. Here, we optimized and deoptimized the codon pair bias (CPB) of the human immunodeficiency virus type 1 (HIV-1) envelope (env) gene to investigate the influence of env synonymous CPB recoding on virus replication capacity, as well as the potential mechanism. We found that env CPB deoptimization did not always generate attenuation, whereas CPB optimization attenuated virus replication in MT-4 cells. Furthermore, virus attenuation correlated with reduced Env protein production but not with decreased viral RNA synthesis. Remarkably, in our model, increasing the number of CpG dinucleotides in the 5' end of env did not reduce the replication capacity of HIV-1. These results indicate that factors other than CPB or CpG content may have impacted the viral fitness of the synonymously recoded study variants. Our findings provide evidence that CPB recoding-associated attenuation can affect translation efficiency. Moreover, we demonstrated that an increased number of CpGs in the 5' end of HIV-1 env is not always associated with reduced virus replication capacity

The Perennial Threat of Yellow Fever

Despite the availability of a safe and effective vaccine, yellow fever remains a major vaccine-preventable disease in endemic regions. Additionally, travelers risk acquiring yellow fever when visiting areas of endemic transmission or locations with ongoing outbreaks. Yellow fever is a viral hemorrhagic fever that has inflicted stigma, illness, and death among human societies. From the 17th to the 19th centuries, yellow fever remained a mysterious illness that predominantly affected tropical regions in Africa, the Caribbean and the Americas. The disease was as feared as cholera or smallpox, and played a significant geopolitical role in shaping modern societies. Epidemics of yellow fever brought out the best and the worst of human nature: the disease spread to new regions during the Atlantic slave trade; while the identification of its causative viral agent and mode of transmission, as well as the development of a vaccine, were made possible by the sacrifice of selfless scientists. Confirmation of the vector transmission of YF paved the way for the development of an effective vaccine in the first half of the 20th century. Encroachment of human settlements into locations with sylvatic transmission has blurred the distinction between the urban and sylvatic cycles. Introduction or expansion of routine immunization activities and reaching hard-to-reach populations consitute public health priorities toward ensuring vaccine equity in endemic areas. It is also critical to ensure the timely immunization of at-risk populations during outbreaks and to promote vaccination of international travelers. We conclude that the threat of YF will linger far into the 21st century as a leading public health emergency of global concern under the International Health Regulations

VISUALIZATION MODEL FOR PRODUCT LIFECYCLE MANAGEMENT

Product Lifecycle Management (PLM) demonstrated to be a good strategy for manufacturing enterprises. In spite of all the benefits it is not still clear how to implement it in industry. This article presents a visualization model of enterprise processes for a PLM system. It presents in a graphic way the main elements of a product lifecycle. The model identifies what is done (process, activities), when it is done (workflows), who does what (roles - skills) and how it can be done better (methods and tools). UML-RUP is used as representation technique. A case study, which analyzes the specification and inspection procedures of geometric tolerances according to the GPS approach, proves the convenience of this model for supporting PLM implementation

Ultrasound Examination of the Ligament Complex Within the Medial Aspect of the Ankle and Foot

To properly diagnose and treat injuries to the ankle or foot, the physician must have good anatomical knowledge of the ligaments involved. The bundles can be distinguished and identified by ultrasound examination of the medial aspect, but this may be a challenging task. In the present illustrated study, we discuss how a detailed ultrasound examination can be made of the different ligaments within the medial aspect of the ankle and foot.Funding for open access charge is provided by Universidad de Malaga/CBU

Inhibición in vitro de Botrytis cinerea con extractos de hojas de vid silvestre (Vitis spp.)

The extracts of wild grapevines (Vitis) leaves (EHVS) from three accessions (P178, E-200 and TN-4) at 6, 8 and 12 % v/v, were tested in vitro to evaluate their inhibitory effect on Botrytis cinerea development. Resveratrol (RVS) (60, 90, 120 µg/mL), citrus extracts (EC) (3, 5 and 8 % v/v) and cyprodinil + fludioxonil (SW) (500, 800 and 1000 µg/mL) were compared against EHVS. In average, SW presented inhibition of mycelial growth (ICM), sporulation (IE) and spore germination (IGC) (88.9; 85.5 and 93.7 %, average respectively). RVS presented the second higher inhibition rate. All EHVS presented antifungal activity; specially, P-178 at 12 % resulted in 72 % ICM, 75 % IE and 62 % IGC. This dose contained phenolic compounds 19.9 mg/mL, RVS 1.7 mg/mL, gallic acid 3.8 mg/mL and ferulic acid 2.5 mg/mL.CONACY