The Studying the Biological Characteristics of the Stingless Bee Tetrigonilla Collina Smith 1857 (Apidae: Melipona) in Hanoi, Vietnam

Stingless bees are distributed in tropical and subtropical regions. There are over 16,000 species of stingless bees around the world, among which, 42 species are from Asia (Kerr & Maule, 1964). Sixteen species of stingless bees have been identified in Vietnam (Sakagami, 1975; Sakagami, 1978; Engel, 2000; Chinh et al., 2005; Rasmussen, 2008). In this study, the biological characteristics of Tetrigonilla collina, as a representative for Southeast Asian stingless bees, were observed and recorded. The worker cell dimensions were 5.30 ± 0.34mm in length by 4.28 ± 0.37mm in width with a volume of 45.02 ± 5.74mL (food volume: 19.05 ± 3.5mL; ratio: 42.27%). The new cells were mostly built in the morning (from 2:00 to 10:00 am) and the queen laid eggs (2.52 ± 0.81 sec per egg) and capped the cells in the afternoon (from 12:00 to 17:00 pm). The average worker-cell building period was 12.03 ± 3.78 hours. Mainly, six of first ten bees that inserted made food discharges in a cell. The food discharge occurred in a very short time, which was 1.58 ± 0.6 minutes. The new cell numbers of the colony were reduced at the end of the experimental period.

Novel silicon bipodal cylinders with controlled resonances and their use as beam steering metasurfaces

Metasurfaces have paved the way for high performance wavefront shaping and beam steering applications. Phase-gradient metasurfaces (PGM) are of high importance owing to the powerful and relatively systematic tool they offer for manipulating electromagnetic wave fronts and achieving various functionalities. Herein, we numerically present a novel unit cell known as bipodal cylinders (BPC), made of Silicon (Si) and placed on a Silicon dioxide (SiO2) substrate to be compatible with CMOS fabrication techniques and to avoid field leakage into a high index substrate. Owing to its geometrical structure, the BPC structure provides a promising unit cell for electromagnetic wave manipulation. We show that BPC offers a way to shift the electric dipole mode to a frequency higher than that of the magnetic dipole mode. We investigate the effect of varying different geometrical parameters on the performance of such unit cell. Building on that, a metasurface is then presented that can achieve efficient electromagnetic beam steering with high transmission of 0.84 and steering angle of 15.2°; with very good agreement with the theoretically predicted angle covering the whole phase range from 0 to 2$$\pi$$ π .

Experimental tests of functional molecular regeneration via a standard framework for coordinating synthetic cell building

The construction of synthetic cells from lifeless ensembles of molecules is expected to require integration of hundreds of genetically-encoded functions whose collective capacities enable self-reproduction in simple environments. To date the regenerative capacities of various life-essential functions tend to be evaluated on an ad hoc basis, with only a handful of functions tested at once and only successful results typically reported. Here, we develop a framework for systematically evaluating the capacity of a system to remake itself. Using the cell-free Protein synthesis Using Recombinant Elements (PURE) as a model system we apply our framework to evaluate the capacity of PURE, whose composition is completely known, to remake 36 life-essential functions. We find that only 23 of the components can be well tested and that only 19 of the 23 can be remade by the system itself; translation release factors remade by PURE are not fully functional. From both a qualitative and quantitative perspective PURE alone cannot remake PURE. We represent our findings via a standard visual form we call the Pureiodic Table that serves as a tool for tracking which life-essential functions can work together in remaking one another and what functions remain to be remade. We curate and represent all available data to create an expanded Pureiodic Table in support of collective coordination among ongoing but independent synthetic cell building efforts. The history of science and technology teaches us that how we organize ourselves will impact how we organize our cells, and vice versa.

An Introduction to the Brain

This chapter emphasizes that human brains are the most complicated animate or inanimate system in the universe. It begins with a discussion of the definition of life and consciousness and the transition from life to consciousness. It is proposed that consciousness began with the ability to learn associatively (classical and operant conditioning) during the Cambrian period. There is a discussion of the four cell-building principles of the brain: cell proliferation, cell differentiation, cell migration, and programmed cell death. The multiple naming systems for the brain are presented: (1) Brodmann’s areas, (2) presumed function, (3) people’s names (4) regional location, (5) location and nature of the structure, and (6) gross anatomical name. The chapter reviews the four major brain lobes and their functions. It covers major structures of the limbic system and emphasizes the functional role of the brain’s fasciculi, the major connections for neural transmission, which reflects the concerted evolution of various brain regions.

Cerebellar Model Controller with new Model of Granule Cell-golgi Cell Building Blocks and Two-phase Learning Acquires Multitude of Generalization Capabilities in Controlling Robot Joint without Exponential Growth in Complexity

Processing in the cerebellum is roughly described as feed forward processing of incoming information over three layers of the cerebellar cortex that send intermediate output to deep cerebellar nuclei, the only output from the cerebellum. Beside this main picture there are several feedback routes, mainly not included in models. In this paper we use new model for neuronal circuit of the cerebellar granule cell layer, as collection of idealized granule cell–golgi cell building blocks with capability of generating multi-dimensional receptive fields modulated by separate input coming to lower dendrite tree of Golgi cell. Resulting cerebellar model controller with two-phase learning will acquire multitude of generalization capabilities when used as robot joint controller. This will usually require more than one Purkinje cell per output. Functionality of granule cell-Golgi cell building block was evaluated with simulations using Simulink single compartment spiking neuronal model. Trained averaging cerebellar model controller attains very good tracking results for wide range of unlearned slower and faster trajectories, with additional improvements by relearning at faster trajectories. Inclusion of new dynamical effects to the controller results with linear growth in complexity for inputs targeting lower dendrite tree of Golgi cell, important for control applications in robotics, but not only.

Towards an understanding of the molecular regulation of carbon allocation in diatoms: the interaction of energy and carbon allocation

In microalgae, the photosynthesis-driven CO 2 assimilation delivers cell building blocks that are used in different biosynthetic pathways. Little is known about how the cell regulates the subsequent carbon allocation to, for example, cell growth or for storage. However, knowledge about these regulatory mechanisms is of high biotechnological and ecological importance. In diatoms, the situation becomes even more complex because, as a consequence of their secondary endosymbiotic origin, the compartmentation of the pathways for the primary metabolic routes is different from green algae. Therefore, the mechanisms to manipulate the carbon allocation pattern cannot be adopted from the green lineage. This review describes the general pathways of cellular energy distribution from light absorption towards the final allocation of carbon into macromolecules and summarizes the current knowledge of diatom-specific allocation patterns. We further describe the (limited) knowledge of regulatory mechanisms of carbon partitioning between lipids, carbohydrates and proteins in diatoms. We present solutions to overcome the problems that hinder the identification of regulatory elements of carbon metabolism. This article is part of the themed issue ‘The peculiar carbon metabolism in diatoms’.

Gypsum Forms in an Unexpected Way

Scientists spot the "stem cell" building blocks that lay the foundation for gypsum's formation.