The Honey Bee Colony's Criterion for Candidate Selection: "Ongoing" or "One-Shot"?

In the honey bee, the queen's death severely threatens the survival of the colony. In an emergency, new queens are reared from young worker larvae, where nepotism is thought to influence the choice of queen candidates by the workers. This article simulates the emergency queen-rearing process in a colony under natural conditions and records the results of colony selection (without nepotism). In queenless colonies, worker larvae aged three days or younger were preferred for queen rearing, and 1-day-old larvae were the first to be selected for the queen-cell cups. In the capping stage, the number of capped queen cells selected from the 1-day-old larvae was much higher than the 3-day-old larvae. On the first day, the number of emerging queens reared from 1-day-old larvae was significantly higher than the queens reared from 2-day-old and 3-day-old larvae. However, there was no significant difference in the birth weights of queens reared from 1-day-old, 2-day-old, or 3-day-old larvae. When the newly emerged queens were introduced into the original queenless colony, 1-day-old larval queens triggered more worker followers than 2-day-old larval queens. The expression of ovarian development-related genes (vg, hex110, and Jh) was higher in queens reared from 1-day-old larvae than those reared from 2-day-old and 3-day-old larvae, indicating that the quality of the queens reared from 1-day-old larvae is superior. This study shows that in the absence of nepotism, the colony selection of queen candidates at the larval stage, capping stage, and emerging stage is not final, but is gradually optimized to maximize colony development through a "quality control" process.

The mechanism of Andrena camellia in digesting toxic sugars.

Camellia oleifera is an economically and medicinally valuable oilseed crop. Honeybee, the most abundant pollinator, rarely visits C. oleifera because of the toxic sugars in the nectar and pollen. These toxic sugars cannot be fully digested by honeybees and inhibit the process of synthesizing trehalose in honeybees. C. oleifera exhibits self-incompatibility, and its pollination heavily depends on Andrena camellia. However, the mechanism by which A. camellia digests toxic sugars in C. oleifera nectar and pollen remains unknown. Consequently, we identified and validated four single-copy genes (α-N-acetyl galactosamine-like, galactokinase, galactose-1-phosphate uridyltransferase, and UDP-galactose-4'-epimerase, abbreviated as NAGA-like, GALK, GALT, and GALE) essential for detoxifying toxic sugars in vitro. Then, we cloned the four genes into Escherichia coli, and expressed enzyme successfully degraded the toxic sugars. The phylogeny suggests that the genes were conserved and functionally diverged among the evolution. These results provide novel insights into pollinator detoxification during co-evolution.

(-)-Gallocatechin Gallate: A Novel Chemical Marker to Distinguish Triadica cochinchinensis Honey.

Triadica cochinchinensis honey (TCH) is collected from the nectar of the medicinal plant T. cochinchinensis and is considered the most important honey variety in southern China. TCH has significant potential medicinal properties and commercial value. However, reliable markers for application in the authentication of TCH have not yet been established. Herein, a comprehensive characterization of the botanical origin and composition of TCH was conducted by determining the palynological characteristics and basic physicochemical parameters. Liquid chromatography tandem-mass spectrometry (LC-MS/MS) was used to investigate the flavonoid profile composition of TCH, T. cochinchinensis nectar (TCN) and 11 other common varieties of Chinese commercial honey. (-)-Gallocatechin gallate (GCG) was identified as a reliable flavonoid marker for TCH, which was uniquely shared with TCN but absent in the other 11 honey types. Furthermore, the authentication method was validated, and an accurate quantification of GCG in TCH and TCN was conducted. Overall, GCG can be applied as a characteristic marker to identify the botanical origin of TCH.

Revealing Changes in Ovarian and Hemolymphatic Metabolites Using Widely Targeted Metabolomics between Newly Emerged and Laying Queens of Honeybee (Apis mellifera).

The queen bee is a central and pivotal figure within the colony, serving as the sole fertile female responsible for its reproduction. The queen possesses an open circulatory system, with her ovaries immersed in hemolymph. A continuous and intricate transportation and interchange of substances exist between the ovaries and hemolymph of queen bees. To determine the characteristic metabolites in the hemolymph and ovary, as well as understand how their rapid metabolism contributes to the process of egg-laying by queens, we reared Apis mellifera queens from three different age groups: newly emerged queen (NEQ), newly laying queen (NLQ), and old laying queen (OLQ). Using widely targeted metabolomics, our study revealed that the laying queen (NLQ and OLQ) exhibited faster fatty acid metabolism, up-regulated expression of antioxidants, and significant depletion of amino acids compared to the NEQ. This study revealed that the levels of carnitine and antioxidants (GSH, 2-O-α-D-glucopyranosyl-L-ascorbic acid, L-ascorbic acid 2-phosphate, etc.) in the NLQ and OLQ were significantly higher compared to NEQ. However, most of the differentially expressed amino acids, such as L-tryptophan, L-tyrosine, L-aspartic acid, etc., detected in NLQ and OLQ were down-regulated compared to the NEQ. Following egg-laying, pathways in the queens change significantly, e.g., Tryptophan metabolism, Tyrosine metabolism, cAMP signaling pathway, etc. Our results suggest that carnitine and antioxidants work together to maintain the redox balance of the queen. Additionally, various amino acids are responsible for maintaining the queen's egg production.

Identification of the Toxic Compounds in Camellia oleifera Honey and Pollen to Honey Bees (Apis mellifera).

Identifying the components of Camellia oleifera honey and pollen and conducting corresponding toxicological tests are essential to revealing the mechanism of Camellia oleifera toxicity to honey bees. In this research, we investigated the saccharides and alkaloids in honey, nectar, and pollen from Camellia oleifera, which were compared with honey, nectar, and pollen from Brassica napus, a widely planted flowering plant. The result showed that melibiose, manninotriose, raffinose, stachyose, and lower amounts of santonin and caffeine were found in Camellia oleifera nectar, pollen, and honey but not in B. napus nectar, pollen, and honey. Toxicological experiments indicated that manninotriose, raffinose, and stachyose in Camellia oleifera honey are toxic to bees, while alkaloids in Camellia oleifera pollen are not toxic to honey bees. The toxicity mechanism of oligosaccharides revealed by temporal metabolic profiling is that oligosaccharides cannot be further digested by honey bees and thus get accumulated in honey bees, disturbing the synthesis and metabolism of trehalose, ultimately causing honey bee mortality.

Large scale application of pulse oximeter and auscultation in screening of neonatal congenital heart disease.

PURPOSE: To conduct a retrospective evaluation of a large clinical implementation of combined pulse oximeter (POX) and cardiac auscultation as a fast-screening device for congenital heart disease (CHD). METHODS: Every newborn in a large maternity healthcare center received auscultation and POX screening within 24 hours after delivery. When an abnormal heart murmur or SpO2 level was detected, an echocardiogram was ordered to confirm the diagnosis of CHD. RESULTS: From January 1, 2018 to December 31, 2019, there were 44,147 livebirths at the studied hospital where 498 suspected CHD were identified: 27 newborns by POX screening and 471 by cardiac auscultation. The diagnosis was further confirmed in 458 neonates through echocardiogram. This result put forth an overall diagnosis rate of 92.0%. Cardiac auscultation detected the majority of CHD cases 438 (95.6%) while POX only screened 20 (4.4%) cases. Interestingly, no CHD case was detected by both auscultation examination and POX screening. Auscultation detected most of the common types of CHD, but POX excelled in identifying rare and critical cases. POX screening alone had a very low accuracy of 74.07% in positive predict value (PPV). On the other hand, auscultation functioned well in terms of PPV and negative predict value (NPV) (92.99 and 99.95%, respectively), but the addition of POX improved the overall screening performance resulting in 100% NPV. We also validate the finding with the data 6 months after the study period. CONCLUSION: Our study demonstrated that addition of pulse oximetry to routine cardiac auscultation could be used as an accurate and feasible screening for early screening of CHD in newborns in large-scale clinical practice.

Influence of Different Bifurcation Angles on the Flame Propagation of Gas Explosions in Three-Way Bifurcated Pipes.

Exploring the flame propagation law in the process of gas explosion under different bifurcation angles is of great significance to the design of coal mine roadway and the prevention of gas explosion accidents. To study the variation of flame propagation law with bifurcation angle, an in-house experimental system based on a small scale three-way bifurcated pipe was developed to perform gas explosion experiments using mixtures of premixed methane-air with a methane concentration of 9.5%. Numerical simulations were conducted to study the propagation of the explosion flame. The results show that, (i) during the flame propagation process, the flame morphology evolves in the following manner: hemispherical, concave entrainment-deformation-flattening; (ii) in the case of gas explosion of three-way bifurcated pipes, there are significant differences in damage at different positions, and the damage at the pipe connection is the most serious. (iii) Although the parameters of the explosion flame in the bifurcated pipe exhibit similar trends across four different bifurcation angles, the values of the flame parameters obtained by the experiments and numerical simulations were not completely consistent. (iv) When the bifurcation angle is between the 45 and 75° bifurcation range, the area of the turbulent vortex formed by the air flow increases as the angle of the pipe widens. The research results analyze the propagation law of gas deflagration flame in the bifurcated pipeline, providing reference for the propagation mechanism of gas deflagration in underground bifurcated roadway and the formulation of prevention measures, which is conducive to preventing the propagation of gas explosion, reducing the intensity, and reducing the loss caused by gas explosion. However, large-scale tests are needed to determine the applicability of small-scale tests and calculations in this paper to full-scale mine conditions.

Protective effects of polydatin against CCl(4)-induced injury to primarily cultured rat hepatocytes.

AIM:To investigate the protective effects of polydatin (PD) against injury to primarily cultured rat hepatocytes induced by CCl(4).METHODS:Rat hepatocytes were separated by methods of liver infusion in vivo and cultured medium (7.5X10(5) cells/mL). Two mL or 0.2mL was added into 24-well or 96-well plates respectively. Twenty-four hours after cell preculture, PD at concentrations of 10(-7) mol/L-10(-4)mol/L was added into each plate. At the same time injury to hepatocytes was induced by adding 10mmol/L CCl(4).Then, 0.1mL or 1mL culture solution was removed from the 96-well or 24-well plates at 6h, 12h, 24h and 48h after CCl14 intoxication respectively for the determination of GPT, GSH and MDA. At 48h, the survivability of rat hepatocytes was assayed by the MTT colormetric method.RESULTS:After CCl(4) challenge, the release of GPT and the formation of MDA in rat hepatocytes markedly increased and maintained at a high level in 48h, whereas PD with different concentrations could markedly inhibit this elevation with 10(-5)mol/L PD having the strongest effects and inhibiting rate was over 50%. PD could also improve the decreased content of GSH caused by CCl(4) in accordance with the doses used. CCl(4) evidently decreased the hepatocyte survivability from 91.0% ± 7.9% to 35.4% ± 3.8%. On the other hand, PD at 10(-7)mol/L-10(-4)mol/L could reverse this change and improve the cell survival rates to 56.1% ± 5.2%, 65.8% ± 5.0%, 88.7% ± 6.8% and 75.2% ± 7.3%, respectively.CONCLUSION: PD at 10(-7)mol/L-10(-4)mol/L could protect primarily cultured rat hepatocytes against CCl(4) induced injury.