277 research outputs found
2-[(4-Chlorophenyl)selanyl]-3,4-dihydro-2H-benzo[h]chromene-5,6-dione: crystal structure and Hirshfeld analysis
The title organoselenium compound, C19H13ClO3Se {systematic name: 2-[(4-chlorophenyl)selanyl]-2H,3H,4H,5H,6H-naphtho[1,2-b]pyran-5,6-dione}, has the substituted 2-pyranyl ring in a half-chair conformation with the methylene-C atom bound to the methine-C atom being the flap atom. The dihedral angle between the two aromatic regions of the molecule is 9.96 (9)° and indicates a step-like conformation. An intramolecular Se...O interaction of 2.8122 (13) Å is noted. In the crystal, π–π contacts between naphthyl rings [inter-centroid distance = 3.7213 (12) Å] and between naphthyl and chlorobenzene rings [inter-centroid distance = 3.7715 (13) Å], along with C—Cl...π(chlorobenzene) contacts, lead to supramolecular layers parallel to the ab plane, which are connected into a three-dimensional architecture via methylene-C—H...O(carbonyl) interactions. The contributions of these and other weak contacts to the Hirshfeld surface is described
Nighttime is the worst time: Parental fear of hypoglycemia in young children with type 1 diabetes
BACKGROUND:
Fear of hypoglycemia is common in parents of young children with type 1 diabetes (T1D), but little is known about the specific fears that parents most often experience. Hypoglycemia fear has been associated with poorer glycemic control in older children, though not yet studied in a large cohort of very young children.
MATERIALS AND METHODS:
Parents of 549 children <7 years (mean 5.2 ± 1.2 years [19% <3 years]) with a mean diabetes duration of 2.4 ± 1.0 years (range 1-6 years) and mean HbA1c 8.2% ± 1.1% (66 ± 12 mmol/mol) registered in the T1D Exchange completed the worry scale of the Hypoglycemia Fear Survey modified for parents (HFS-P).
RESULTS:
Mean parental fear of hypoglycemia worry score was 36.1 ± 23.1 (possible range 0-100), with most frequent worries related to the child having a low while asleep and the child not recognizing a low. The mean worry score was not associated with the child's age, glycemic control, or recent severe hypoglycemic event. Parental worries about lows while sleeping were significantly higher in pump users than non-users (61% vs. 45%; P < .001), and tended to be higher in CGM users than non-users (62% vs 51%; P = .02).
CONCLUSIONS:
The greatest worries of parents of young children with T1D were related to hypoglycemia during sleep and other times/circumstances during which it would be difficult to detect hypoglycemia. Using advanced diabetes technologies may be an effort to temper fears about hypoglycemia during sleep, though the directionality of this relationship is undetermined. Additional studies can clarify this association and leverage use of diabetes technologies to improve glycemic control
Reproductive protein evolution in two cryptic species of marine chordate
<p>Abstract</p> <p>Background</p> <p>Reproductive character displacement (RCD) is a common and taxonomically widespread pattern. In marine broadcast spawning organisms, behavioral and mechanical isolation are absent and prezygotic barriers between species often operate only during the fertilization process. Such barriers are usually a consequence of differences in the way in which sperm and egg proteins interact, so RCD can be manifest as faster evolution of these proteins between species in sympatry than allopatry. Rapid evolution of these proteins often appears to be a consequence of positive (directional) selection. Here, we identify a set of candidate gamete recognition proteins (GRPs) in the ascidian <it>Ciona intestinalis </it>and showed that these GRPs evolve more rapidly than control proteins (those not involved in gamete recognition). Choosing a subset of these gamete recognition proteins that show evidence of positive selection (CIPRO37.40.1, CIPRO60.5.1, CIPRO100.7.1), we then directly test the RCD hypothesis by comparing divergence (omega) and polymorphism (McDonald-Kreitman, Tajima's D, Fu and Li's D and F, Fay and Wu's H) statistics in sympatric and allopatric populations of two distinct forms of <it>C. intestinalis </it>(Types A and B) between which there are strong post-zygotic barriers.</p> <p>Results</p> <p>Candidate gamete recognition proteins from two lineages of <it>C. intestinalis </it>(Type A and B) are evolving more rapidly than control proteins, consistent with patterns seen in insects and mammals. However, ω (d<sub>N</sub>/d<sub>S</sub>) is not significantly different between the sympatric and allopatric populations, and none of the polymorphism statistics show significant differences between sympatric and allopatric populations.</p> <p>Conclusions</p> <p>Enhanced prezygotic isolation in sympatry has become a well-known feature of gamete recognition proteins in marine broadcast spawners. But in most cases the evolutionary process or processes responsible for this pattern have not been identified. Although gamete recognition proteins in <it>C. intestinalis </it>do appear to evolve more rapidly, on average, than proteins with other functions, rates of evolution are not different in allopatric and sympatric populations of the two reproductively isolated forms. That sympatry is probably human-mediated, and therefore recent, may explain the absence of RCD.</p
Intra-regional transportation of a tugboat fouling community between the ports of recife and natal, northeast Brazil
This study aimed to identify the incrusting and sedentary animals associated with the hull of a tugboat active in the ports of Pernambuco and later loaned to the port of Natal, Rio Grande do Norte. Thus, areas with dense biofouling were scraped and the species then classified in terms of their bioinvasive status for the Brazilian coast. Six were native to Brazil, two were cryptogenic and 16 nonindigenous; nine of the latter were classified as established (Musculus lateralis, Sphenia fragilis, Balanus trigonus, Biflustra savartii, Botrylloides nigrum, Didemnum psammatodes, Herdmania pallida, Microscosmus exasperatus, and Symplegma rubra) and three as invasive (Mytilopsis leucophaeta, Amphibalanus reticulatus, and Striatobalanus amaryllis). The presence of M. leucophaeata, Amphibalanus eburneus and A. reticulatus on the boat's hull propitiated their introduction onto the Natal coast. The occurrence of a great number of tunicate species in Natal reflected the port area's benthic diversity and facilitated the inclusion of two bivalves - Musculus lateralis and Sphenia fragilis - found in their siphons and in the interstices between colonies or individuals, respectively. The results show the role of biofouling on boat hulls in the introduction of nonindigenous species and that the port of Recife acts as a source of some species.Este trabalho objetivou identificar os animais incrustantes e sedentários associados ao casco de um rebocador que atuava nos Portos de Pernambuco e foi cedido para o Porto de Natal, Rio Grande do Norte. Áreas com densa bioincrustação foram raspadas e as espécies foram posteriormente classificadas em relação ao status de bioinvasão no litoral brasileiro. Dentre as espécies identificadas, seis eram nativas do Brasil, duas criptogênicas e 16 exóticas. Destas, oito foram classificadas como estabelecidas (Musculus lateralis, Sphenia fragilis, Balanus trigonus, Biflustra savartii, Botrylloides nigrum, Didemnum psammatodes, Herdmania pallida, Microscosmus exasperatus, Symplegma rubra) e três como invasoras (Mytilopsis leucophaeta, Amphibalanus reticulatus e Striatobalanus amaryllis). A presença de M. leucophaeata, Amphibalanus eburneus e A. reticulatus no casco da embarcação, propiciou sua introdução na costa de Natal. A ocorrência de grande número de espécies de tunicados em Natal refletiu a biodiversidade bêntica da área portuária e facilitou a inclusão de dois bivalves, Musculus lateralis e Sphenia fragilis, encontrados em seus sifões e nos interstícios entre colônias ou indivíduos, respectivamente. Os dados obtidos indicam que a incrustação em cascos de embarcações tem um papel preponderante na introdução de espécies exóticas, e que o Porto do Recife atuou como fonte de algumas destas espécies
Analysis of an alternative method for the study of bromeliad-associated fauna in plants with different foliar organization
Avaliação imunohistoquímica e ultraestrutural de gametas e embriões caprinos infectados com o CAEV.
O objetivo do presente estudo foi determinar a susceptibilidade dos folículos ovarianos, espermatozoides e embriões caprinos ao Vírus da Artrite Encefalite Caprina (CAEV). Para isto, foram analisados espermatozoides e folículos ovarianos pelas técnicas de imunohistoquímica e microscopia eletrônica de transmissão, antes e após protocolos de infecção in vitro com o CAEV. Foram submetidos à análise ultraestrutural, embriões caprinos produzidos in vivo, oriundos de cabras negativas e positivas para o CAEV. Nas amostras seminais, provenientes de animais tanto com infecção natural quanto dos artificialmente infectados, foi observada imunomarcação positiva dos espermatozoides, assim como alterações degenerativas na sua análise ultraestrutural. Já nas amostras de tecido ovariano, a imunomarcação foi mais discreta e identificada na região do estroma. No tocante à análise ultraestrutural, folículos e embriões se apresentaram íntegros. De acordo com esses resultados, pode-se concluir que os espermatozoides caprinos apresentaram-se infectados, assinalando a susceptibilidade dessas células ao vírus, bem como a potencialidade do CAEV ser carreado ao cerne do oócito, originando embriões infectados
- …
