With the enrichment of metabolomic information in a diverse number of plants, the obtained datasets reflect on important aspects of plant growth, function, physiology, productivity, and adaptation to changing biotic and abiotic environments. Many of these plant species are natural polyploids that are either model plants, crops, or are of commercial interest. Decades of efforts have resulted in artificially induced polyploids from in vitro micropropagation practices as well. Recent efforts using next generation, high throughput genome sequencing approaches have contributed to our growing understanding of their genome ploidy status and the inherent biosynthetic potentials of encoded metabolomes. However, the ever perplexing questions galore regarding the metabolic status of these polyploids across plant genomes remained. Thus,...
Borazine (B3N3H6) is known as ‘inorganic benzene’ because of a planar B3N3 ring with equivalent B-N distance. The lone pair from N in the ring delocalize to the adjacent p-orbital of B which leads to a conjugated system. Even though metal-benzene complexes have been studied extensively as models for cation- π interactions and organometallic bonding, similar systems with borazine is relatively scarce. Here, we present a density functional study on metal cation-borazine complexes focusing on geometric and electronic structures and their effects on infrared spectra. We have chosen Al, V, Mn, and Zn cations with various d-configurations which provide models for study donor-acceptor complexes. Among these four metal complexes, Al+ and Mn+ prefer to bind to π-cloud on top of the borazine ring. On the other hand, V+ and Zn+ bind to B and N, respectively.
Tying what teachers earn to what students learn has reemerged as an important educational policy lever and regained much interest among researchers and policymakers both in the United States and around the world (Liang, 2013; Liang & Akiba, 2011; Podgursky & Springer, 2007). Theoretically, performance pay programs can (a) motivate teachers to strengthen their instruction, (b) improve the quality of the teaching profession, and (c) enhance student learning (Lazear, 2003). On the first issue, a recent study has provided some evidence that when aligned with teacher evaluation focusing on instruction, performance related pay is promising in enhancing teachers’ instructional practices (Liang & Akiba, 2015). On the second one, we still have no evidence of its impact on teacher recruitment and retention.
This opinion comments on a recent trend in science showing a proliferation of published material, while at the same time citation rate seems to drop faster than ever. It is suggested that the faster pace of scientific publication on the internet poses new challenges for the whole research community.
Novel symmetric biodegradable dendritic tri-block copolymer, consisting of a core of hydrophobic poly(L-lactide) (PLLA) block and 32 poly(L-lysine) (PLL) arms, was synthesized via a facile chemistry route. The as-synthesized tri-block copolymer was characterized with 1H NMR, water contact angle measurements, GPC test, and DSC analysis. The 1H NMR and GPC tests indicated that the tri-block copolymer, PLL-PLLA-PLL, with well-defined architecture was synthesized. The water contact angle measurements demonstrated that the incorporation of L-lysine improved prominently the hydrophilicity, and the DSC analysis indicated that the crystalline region of PLLA was slightly modified by the L-lysine component, decreasing melting temperature and crystallinity in the PLL-PLLA-PLL copolymer. NPCs and PC12 cells were seeded on PLLA, dendritic PLLA with 32 L-lysine terminals (d-PLLA-d), and PLL-PLLA-PLL films to investigate cell attachment, proliferation, and differentiation. The results strongly demonstrated that d-PLLA-d and PLL-PLLA-PLL films, especially PLL-PLLA-PLL films, dramatically promoted cell attachment, proliferation, and, more importantly, differentiation, particularly neurite outgrowth.
Host defense (antimicrobial) peptides (HDPs) are produced by virtually all organisms and have an important role in protection against microbial infections. Some naturally occurring peptides such as the human cathelicidin LL-37 and the bovine peptide indolicidin have been shown to inhibit bacterial biofilm development. Rearrangement and substantial modification of the amino acid sequence of these and other HDPs has led to the identification of small synthetic peptides with increased, broad-spectrum anti-biofilm activity that is independent of activity vs. planktonic cells. Some of these peptides have also been shown to act in synergy with antibiotics commonly used in the clinic to prevent biofilm formation and eradicate pre-existing biofilms. Recently, the mechanism of action of one of these peptides (i.e., 1018) was shown to involve binding to and causing degradation of the second messenger stress response nucleotide ppGpp, which plays an important role in biofilm formation and maintenance. Here, we review recent progress in the field of anti-biofilm peptides and propose future directions to further develop these therapeutic agents.
Glycated hemoglobin is a clinically established important biomarker that provides retrospective value of blood glucose concentration over the preceding 2-3 months. Owing to the biochemical specificity and multiplexing capability, Raman spectroscopy has emerged as a promising tool for detection and quantification of blood constituents in a label-free and non-destructive manner. Here, we critically review the Raman spectroscopy-based approach to detect and quantify this important biomarker. The potential of this spectroscopy-based approach and its possible clinical translation from the current optical bench will be also briefly discussed along with the future prospects.
This comparative study used the latest Trends in International Mathematics and Science Study (TIMSS) data sets and examined the relationship between professional development and student achievement. It found that although the national levels of access for students at the fourth and eighth grade levels to teachers who participated in professional learning in the United States were higher than the other countries, one third to one half of the fourth grades were taught by teachers who had no professional learning focusing on math instruction or curriculum. In addition, teachers’ participation in professional development was positively associated with higher student math achievement. This cross-national study provided empirical evidence highlighting the importance of investing in teacher learning for improving national educational quality.