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Plastid and mitchondrial genome evolution of legumes (Fabaceae)
Plastid genome (plastome) organization is highly conserved across seed plants with a quadripartite structure including the small single copy (SSC), the large single copy (LSC) and two copies of an inverted repeat (IR). There are several unrelated lineages that have experienced extensive structural rearrangements such as inversions and gene/intron losses and indels. Fabaceae is typically recognized as having three subfamilies: Caesalpinioideae, Mimosoideae and Papilionoideae. Publicly available plastid genomes of legumes have for the most part been limited to the subfamily Papilionoideae due to their economic importance and known structural rearrangements. In several other angiosperm lineages, correlations between accelerated rates of genomic rearrangements and nucleotide substitition rates in the plastome have been identified. Additionally, increased frequency of plastome structural changes and accelerated nucleotide substitutions have been shown to be correlated with increased evolutionary rates in the mitochondrial genome (mitogenome). To date, few legume mitochondrial genomes (7) are publicly available. My dissertation research uses Fabaceae to investigate 1) plastid genomic changes and rearrangements across all three subfamilies and 2) correlations between biological features and nucleotide substitution rates of both plastid and mitochondrial genes. Chapter two focuses on plastid structural evolution across three subfamilies of Fabaceae and shows papilionoids have smaller genomes with varying degrees of genomic rearrangements, and they have experienced multiple, independent gene/intron losses and inversions that limit the phylogenetic utility of these changes. Chapter three finds accelerated substitution rates in protein coding plastome genes among papilionoid taxa, especially those lacking one copy of the inverted repeat (IR), decreased rates in genes previously contained in the IR, and faster rates in herbaceous versus woody taxa. Chapter four focuses on substitution rates of mitochondrial genes and shows a correlation between plastid and mitochondrial substitution rates in addition to an acceleration in the papilionoid taxa, where, again, the herbaceous habit is correlated with higher rates.Plant Biolog
Genetic Organization of Acquired Antimicrobial Resistance Genes and Detection of Resistance-Mediating Mutations in a Gallibacterium anatis Isolate from a Calf Suffering from a Respiratory Tract Infection
Gallibacterium (G.) anatis isolates associated with respiratory diseases in calves and harboring acquired antimicrobial resistance genes have been described in Belgium. The aim of this study was to analyze the genetic organization of acquired resistance genes in the G. anatis isolate IMT49310 from a German calf suffering from a respiratory tract infection. The isolate was submitted to antimicrobial susceptibility testing, and a closed genome was obtained by a hybrid assembly of Illumina MiSeq short-reads and MinION long-reads. Isolate IMT49310 showed elevated MIC values for macrolides, aminoglycosides, florfenicol, tetracyclines, and trimethoprim/sulfamethoxazole. The acquired resistance genes catA1, floR, aadA1, aadB, aphA1, strA, tet(M), tet(B), erm(B), and sul2 were identified within three resistance gene regions in the genome, some of which were associated with IS elements, such as ISVsa5-like or IS15DII. Furthermore, nucleotide exchanges within the QRDRs of gyrA and parC, resulting in amino acid exchanges S83F and D87A in GyrA and S80I in ParC, were identified. Even if the role in the pathogenesis of respiratory tract infections in cattle needs to be further investigated, the identification of a G. anatis isolate with reduced susceptibility to regularly used antimicrobial agents in cases of fatal bovine respiratory tract infections is worrisome, and such isolates might also act as a reservoir for antimicrobial resistance genes
Экспериментальное исследование синхронного генератора периодических импульсов
Приводятся результаты экспериментального исследования влияния величины нагрузки синхронного генератора периодических импульсов с обычной геометрией зубцовой зоны на форму импульсов тока. Рассматривается возможность регулировки параметров импульсов
Fast Mapping of Terahertz Bursting Thresholds and Characteristics at Synchrotron Light Sources
Dedicated optics with extremely short electron bunches enable synchrotron
light sources to generate intense coherent THz radiation. The high degree of
spatial compression in this so-called low-alpha optics entails a complex
longitudinal dynamics of the electron bunches, which can be probed studying the
fluctuations in the emitted terahertz radiation caused by the micro-bunching
instability ("bursting"). This article presents a "quasi-instantaneous" method
for measuring the bursting characteristics by simultaneously collecting and
evaluating the information from all bunches in a multi-bunch fill, reducing the
measurement time from hours to seconds. This speed-up allows systematic studies
of the bursting characteristics for various accelerator settings within a
single fill of the machine, enabling a comprehensive comparison of the measured
bursting thresholds with theoretical predictions by the bunched-beam theory.
This paper introduces the method and presents first results obtained at the
ANKA synchrotron radiation facility.Comment: 7 pages, 7 figures, to be published in Physical Review Accelerators
and Beam
Two pore domain potassium channels in cerebral ischemia: a focus on K2P9.1 (TASK3, KCNK9)
BACKGROUND: Recently, members of the two-pore domain potassium channel family (K2P channels) could be shown to be involved in mechanisms contributing to neuronal damage after cerebral ischemia. K2P3.1-/- animals showed larger infarct volumes and a worse functional outcome following experimentally induced ischemic stroke. Here, we question the role of the closely related K2P channel K2P9.1. METHODS: We combine electrophysiological recordings in brain-slice preparations of wildtype and K2P9.1-/- mice with an in vivo model of cerebral ischemia (transient middle cerebral artery occlusion (tMCAO)) to depict a functional impact of K2P9.1 in stroke formation. RESULTS: Patch-clamp recordings reveal that currents mediated through K2P9.1 can be obtained in slice preparations of the dorsal lateral geniculate nucleus (dLGN) as a model of central nervous relay neurons. Current characteristics are indicative of K2P9.1 as they display an increase upon removal of extracellular divalent cations, an outward rectification and a reversal potential close to the potassium equilibrium potential. Lowering extracellular pH values from 7.35 to 6.0 showed comparable current reductions in neurons from wildtype and K2P9.1-/- mice (68.31 +/- 9.80% and 69.92 +/- 11.65%, respectively). These results could be translated in an in vivo model of cerebral ischemia where infarct volumes and functional outcomes showed a none significant tendency towards smaller infarct volumes in K2P9.1-/- animals compared to wildtype mice 24 hours after 60 min of tMCAO induction (60.50 +/- 17.31 mm3 and 47.10 +/- 19.26 mm3, respectively). CONCLUSIONS: Together with findings from earlier studies on K2P2.1-/- and K2P3.1-/- mice, the results of the present study on K2P9.1-/- mice indicate a differential contribution of K2P channel subtypes to the diverse and complex in vivo effects in rodent models of cerebral ischemia
Rollerball microendoscope for mosaicking in high-resolution oral imaging
Only 40% of oral cancers are diagnosed at an early, localized stage, when treatment is most effective [1]. Thus, implementing diagnostic imaging tools for early detection of highgrade dysplasia and cancer may help improve the survival rate of oral cancer patients [2]. The highresolution microendoscope (HRME) is a compact, portable, fiberbased imaging device that can image cell nuclei in tissue labeled with the fluorescent contrast agent proflavine [3]. The HRME allows clinicians to noninvasively image the size, shape and distribution of epithelial cell nuclei in vivo, enabling realtime evaluation of potentially neoplastic lesions [3]. The primary limitation of the HRME is the small field of view of its fiber probe (720 μm), which makes it timeconsuming to examine large areas of tissue. Mosaicking algorithms have previously been implemented to allow realtime generation of image mosaics during HRME imaging, thus interrogating a larger field of view than the fiber probe’s diameter [4]. However, this approach has had limited success in vivo due to the practical difficulty of translating the fiber probe across the tissue in a smooth, controlled manner in order for the mosaicking software to function properly. Here we report the construction and initial testing of a rollerball HRME probe that permits smooth, rolling translation across the tissue surface while maintaining image quality with subcellular resolution. The rollerball HRME consists of a standard HRME probe interfaced with a rollerball mechanism. The mechanism is composed of two 5mm sapphire ball lenses enclosed within a 3D printed penlike casing. The ball lenses serve as an optical relay, while the distal ball lens also serves as a rolling contact point with the tissue surface. Figure 1 shows the use of the rollerball HRME to generate a realtime mosaic of a calibration target (field finder slide) as it rolls across the surface of the target. Figure 2 shows the use of the rollerball HRME to generate a realtime mosaic showing cell nuclei on the lateral tongue of a healthy volunteer as it rolls across the tissue surface. The rollerball HRME will allow clinicians to more rapidly examine large areas of tissue with subcellular resolution, potentially aiding in the early detection of highgrade oral dysplasia and cance.
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Chironomid (Insecta: Chironomidae) community structure response to hydrological changes in the mid-1950s in lake Nam Co, Tibetan Plateau
The recent rise in air temperatures detected at high altitudes of the Tibetan Plateau has accelerated glacier melt and retreat. Moreover, enhanced monsoonal precipitation has increased runoff and transport of allochthonous material to the lakes. Consequently, water levels are rising, modifying the spatial distribution and composition of local aquatic biota. To infer these environmental and biological changes in recent decades, a 30-cm-long sediment core, representing the past ~160 years, from Nam Co, an endorheic lake, was analyzed for subfossil chironomid assemblages and sediment geochemistry. In total, 25 chironomid morphotypes were identified. Nineteen were considered as non-rare taxa (abundances ≥2%) and six as rare taxa (abundances <2%). Since 1956 ce, higher chironomid richness (S = 19) is evident compared to the previous 100 years. The simultaneous decrease in the abundance of profundal Micropsectra radialis-type and increase of both Chironomus and Procladius, taxa adapted to more eurytopic and slightly warmer water bodies, indicate increasing water temperatures and intensified primary productivity. The dominance of littoral chironomid assemblages reflects increasing lake water levels, flooded shorelines and expansion of littoral areas driven by increased precipitation and glacial meltwater input both resulting from the increase in air temperatures. This scenario is confirmed by increases in total nitrogen and Zr/Rb ratios, indicating higher productivity and coarser grain size as a consequence of increased runoff via the Niya Qu. These hydrological changes have resulted in a positive water balance that can be linked to an increase in moisture supply from the Indian summer monsoon and glacier melt, reflecting increasing temperatures and precipitation since 1956 ce, ultimately driven by anthropogenic warming
Reconstruyendo vidas: las proyecciones sobre una nueva estructura de vivienda colectiva vertical en el multifamiliar de Tlalpan, México, 2019
El Multifamiliar Tlalpan fue un proyecto de vivienda realizado por el gobierno mexicano del presidenteMiguel Alemán (1945 y 1960). Y si bien soportó dos sismos (1957 y 1985), con el del 19 de septiembre del2017 colapsó debido al desgaste natural propio de su antigüedad (más de 60 años) y las secuelas de los dossismos mencionados. El Edificio 1C fue el más afectado, aunque, gracias a la actuación inmediata de unasociedad involucrada y activa, autoridades responsables e instituciones comprometidas con las necesidades de las personas damnificadas, las consecuencias no fueron tan graves. Es que, por primera vez en la historia mexicana, se forjó un compromiso y una organización coordinada nuevas viviendas colaborativas verticales sostenibles, la construcción del patrimonio de las familias mexicanas que lo perdieron todo, y el acompañamiento desde lo social y emocional que representa todavía para muchos esta desgracia.Palabras Clave: Sostenibilidad, co-responsabilidad, viviendas colaborativas, intergeneracional.
AbstractMultifamiliar Tlalpan was a housing project carried out by the Mexican government of President Miguel Aleman (1945 and 1960). Although it endured two earthquakes (1957 and 1985), with the one of September 19, 2017, it collapsed due to the natural deterioration proper to its antiquity (more than 60 years) and the consequences of the two earthquakes mentioned. Building 1C was the most affected, although, due to the immediate action of an involved and active society, responsible authorities and institutions committed to the needs of the people affected, the consequences were not so serious. This is because, for the first time in Mexican history, a commitment was forged and a coordinated organization that co-responsibly carries out the generation of new sustainable vertical collaborative housing, the construction of the heritage of Mexican families that lost everything, and the accompaniment from the social and emotional side that this misfortune still represents for many.Keywords: Sustainability, Co-responsibility, Co-housing, intergenerational
Using Comparative Genomics for Inquiry-Based Learning to Dissect Virulence of Escherichia coli O157:H7 and Yersinia pestis
Genomics and bioinformatics are topics of increasing interest in undergraduate biological science curricula. Many existing exercises focus on gene annotation and analysis of a single genome. In this paper, we present two educational modules designed to enable students to learn and apply fundamental concepts in comparative genomics using examples related to bacterial pathogenesis. Students first examine alignments of genomes of Escherichia coli O157:H7 strains isolated from three food-poisoning outbreaks using the multiple-genome alignment tool Mauve. Students investigate conservation of virulence factors using the Mauve viewer and by browsing annotations available at the A Systematic Annotation Package for Community Analysis of Genomes database. In the second module, students use an alignment of five Yersinia pestis genomes to analyze single-nucleotide polymorphisms of three genes to classify strains into biovar groups. Students are then given sequences of bacterial DNA amplified from the teeth of corpses from the first and second pandemics of the bubonic plague and asked to classify these new samples. Learning-assessment results reveal student improvement in self-efficacy and content knowledge, as well as students’ ability to use BLAST to identify genomic islands and conduct analyses of virulence factors from E. coli O157:H7 or Y. pestis. Each of these educational modules offers educators new ready-to-implement resources for integrating comparative genomic topics into their curricula
Base de datos de flora y fauna en Galicia
Sección: NoticiasLa Biblioteca del Instituto de Investigaciones Marinas de Vigo recopila, desde 1984 aproximadamente, una base de datos sobre Galicia que nació a partir de unas citas bibliográficas seleccionadas por un investigador de este centro y se fue ampliando en vista de la enorme solicitud de esta información que nos iban haciendo nuestros usuarios, sobre todo los externos al centroPeer reviewe
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