Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

The Role of Sirt6 in Obesity and Diabetes

Sirt6 is one of the sirtuin family members, a kind of NAD+-dependent histone deacetylase and ADP-ribose transferase enzyme. It has an important role in physiological and pathological processes, regulating aging, cancer, obesity, insulin resistance, inflammation, and energy metabolism. Recent studies have suggested that reduced Sirt6 action is related to obesity and diabetes. Aging and overnutrition, two major risk factors for obesity and diabetes, lead to decreased Sirt6 level and function, which results in abnormal glucose and lipid metabolism. Whole-body ablation of Sirt6 in mice results in severe hypoglycemia. Sirt6 deficiency leads to liver steatosis and promotes diet-induced obesity and insulin resistance. Sirt6 has a protective effect on obesity and diabetes. This review surveys evidence for an emerging role of Sirt6 as a regulator of metabolism in mammals and summarizes its major functions in obesity and diabetes

Next generation manufacturing in Singapore

The regional economic crisis and the more recent terrorist attacks have been watershed events for Singapore. Although Singapore emerged relatively unscathed from these upheavals, the economic challenges remain ever-daunting and furthermore, the playing field has been elevated from regionalization to globalization. Therefore, as part of the restructuring strategy, Singapore has identified manufacturing and services as the main engines for growth in the near future. However, by merely attracting manufacturers here to invest is no longer sufficient. It was realized that the much more value has to be added through upgrading the entire manufacturing sector by developing a new set of skills and capabilities, collectively known as Next Generation Manufacturing (NGM). Thus, the main aim of this report is to investigate how NGM can be applied to the Singapore context in preparation for tougher competition in the years to come.​Master of Science (IMST

A new species of Glyptapanteles Ashmead (Hymenoptera, Braconidae, Microgastrinae) within Macrobrochis gigas (Lepidoptera, Arctiidae, Lithosiidae) in Fujian, China

The south-east coastal area of Fujian, China, belongs to the Oriental Realm, and is characterized by a high insect species richness. In this work, a new species of Hymenopteran parasitoid, Glyptapanteles gigas Liang & Song, sp. nov. found in Jinjiang within hosts of caterpillars Macrobrochis gigas (Lepidoptera: Arctiidae), is described and illustrated, with differences from similar species. Additionally, we presumed that both parasitoid and host species play very important role in the coevolution and tritrophic interaction between plants, phytophagous insects, and their parasitoids, because these insects probably broke the sporangia and made contributions to their colonization, or some spores were spread for long distances by adult moths after their emergence, or some parasitoids were attracted by the eggs and larvae of these caterpillars, which was also thought to be helpful to spread of spores

A new species of Glyptapanteles Ashmead (Hymenoptera, Braconidae, Microgastrinae) within Macrobrochis gigas (Lepidoptera, Arctiidae, Lithosiidae) in Fujian, China

The south-east coastal area of Fujian, China, belongs to the Oriental Realm, and is characterized by a high insect species richness. In this work, a new species of Hymenopteran parasitoid, Glyptapanteles gigas Liang & Song, sp. nov. found in Jinjiang within hosts of caterpillars Macrobrochis gigas (Lepidoptera: Arctiidae), is described and illustrated, with differences from similar species. Additionally, we presumed that both parasitoid and host species play very important role in the coevolution and tritrophic interaction between plants, phytophagous insects, and their parasitoids, because these insects probably broke the sporangia and made contributions to their colonization, or some spores were spread for long distances by adult moths after their emergence, or some parasitoids were attracted by the eggs and larvae of these caterpillars, which was also thought to be helpful to spread of spores

Comparative mitochondrial genome analysis of Dendrolimus houi (Lepidoptera: Lasiocampidae) and phylogenetic relationship among Lasiocampidae species.

Dendrolimus houi is one of the most common caterpillars infesting Gymnosperm trees, and widely distributed in several countries in Southeast Asia, and exists soley or coexists with several congeners and some Lasiocampidae species in various forest habitats. However, natural hybrids occasionally occur among some closely related species in the same habitat, and host preference, extreme climate stress, and geographic isolation probably lead to their uncertain taxonomic consensus. The mitochondrial DNA (mtDNA) of D. houi was extracted and sequenced by using high-throughput technology, and the mitogenome composition and characteristics were compared and analyzed of these species, then the phylogenetic relationship was constructed using the maximum likelihood method (ML) and the Bayesian method (BI) based on their 13 protein-coding genes (PCGs) dataset, which were combined and made available to download which were combined and made available to download among global Lasiocampidae species data. Mitogenome of D. houi was 15,373 bp in length, with 37 genes, including 13 PCGs, 22 tRNA genes (tRNAs) and 2 rRNA genes (rRNAs). The positions and sequences of genes were consistent with those of most known Lasiocampidae species. The nucleotide composition was highly A+T biased, accounting for ~80% of the whole mitogenome. All start codons of PCGs belonged to typical start codons ATN except for COI which used CGA, and most stop codons ended with standard TAA or TAG, while COI, COII, ND4 ended with incomplete T. Only tRNASer (AGN) lacked DHU arm, while the remainder formed a typical "clover-shaped" secondary structure. For Lasiocampidae species, their complete mitochondrial genomes ranged from 15,281 to 15,570 bp in length, and all first genes started from trnM in the same direction. And base composition was biased toward A and T. Finally, both two methods (ML and BI) separately revealed that the same phylogenetic relationship of D. spp. as ((((D. punctatus + D. tabulaeformis) + D. spectabilis) + D. superans) + (D. kikuchii of Hunan population + D. houi) as in previous research, but results were different in that D. kikuchii from a Yunnan population was included, indicating that different geographical populations of insects have differentiated. And the phylogenetic relationship among Lasiocampidae species was ((((Dendrolimus) + Kunugia) + Euthrix) + Trabala). This provides a better theoretical basis for Lasiocampidae evolution and classification for future research directions