New fossils of Australopithecus sediba reveal a nearly complete lower back

Adaptations of the lower back to bipedalism are frequently discussed but infrequently demonstrated in early fossil hominins. Newly discovered lumbar vertebrae contribute to a near-complete lower back of Malapa Hominin 2 (MH2), offering additional insights into posture and locomotion in Australopithecus sediba. We show that MH2 possessed a lower back consistent with lumbar lordosis and other adaptations to bipedalism, including an increase in the width of intervertebral articular facets from the upper to lower lumbar column (‘pyramidal configuration’). These results contrast with some recent work on lordosis in fossil hominins, where MH2 was argued to demonstrate no appreciable lordosis (‘hypolordosis’) similar to Neandertals. Our three-dimensional geometric morphometric (3D GM) analyses show that MH2’s nearly complete middle lumbar vertebra is human-like in overall shape but its vertebral body is somewhat intermediate in shape between modern humans and great apes. Additionally, it bears long, cranially and ventrally oriented costal (transverse) processes, implying powerful trunk musculature. We interpret this combination of features to indicate that A. sediba used its lower back in both bipedal and arboreal positional behaviors, as previously suggested based on multiple lines of evidence from other parts of the skeleton and reconstructed paleobiology of A. sediba.

In-orbit results from the attitude determination and control system of ALSAT-2B

ABSTRACT The Algerian Space Agency has been active in the field of microsatellite engineering for more than 15 years and has successfully developed microsatellites under several know-how transfer technology programs, six to date. This paper presents the flight results and lessons learned from the attitude determination and control system (ADCS) flown on the ALSAT-2B satellite, an Earth observation microsatellite, by analysing the behaviour of the satellite from the initial attitude acquisition through the coarse pointing mode then the nominal mode, where the payload is first tested, and finally the orbit control mode. The spacecraft was launched on 26 September 2016 and placed into a 670km Sun-synchronous orbit with a solar local time at an ascending node of 22:15. The ADCS performance presented here mainly focuses on the launch and early operation results. ALSAT-2B includes four reaction wheels in a pyramidal configuration, three gyros, three Sun sensors, three magneto-torquers, one magnetometer, and one star tracker for agile and accurate attitude control. In addition, a propulsion system based on four 1N hydrazine thrusters is also used on board the microsatellite. The main new development in this platform compared with previous ones of the same type is the fusion of the star tracker and measurements by the three gyroscopes into one gyrostellar estimator that was implemented for the first time on ALSAT-2B, and the pyramidal configuration of the wheels, aiming to increase the angular momentum. The results obtained from the early launch operations for different ADCS modes are very encouraging and fulfil all the requirements set during design and testing. Currently, the satellite has accomplished its fourth year in orbit and is still operational and producing high-quality images.

New fossils of Australopithecus sediba reveal a nearly complete lower back

Adaptations of the lower back to bipedalism are frequently discussed but infrequently demonstrated in early fossil hominins. Newly discovered lumbar vertebrae contribute to a near-complete lower back of Malapa Hominin 2 (MH2), offering additional insights into posture and locomotion in Australopithecus sediba. We show that MH2 demonstrates a lower back consistent with human-like lumbar lordosis and other adaptations to bipedalism, including an increase in the width of intervertebral articular facets from the upper to lower lumbar column (“pyramidal configuration”). This contrasts with recent work on lordosis in fossil hominins, where MH2 was argued to demonstrate no appreciable lordosis (“hypolordosis”) similar to Neandertals. Our three-dimensional geometric morphometric (3D GM) analyses show that MH2’s nearly complete middle lumbar vertebra is human-like in shape but bears large, cranially-directed transverse processes, implying powerful trunk musculature. We interpret this combination of features to indicate that A. sediba used its lower back in both human-like bipedalism and ape-like arboreal positional behaviors, as previously suggested based on multiple lines of evidence from other parts of the skeleton and reconstructed paleobiology of A. sediba.

Design and validation of an MPC controller for CMG-based testbed

In the last years, Control Moment Gyros (CMGs) are widely used for high-speed attitude control, since they are able to generate larger torque compared to “classical” actuation systems, such as Reaction Wheels . This paper describes the attitude control problem of a spacecraft, using a Model Predictive Control method. The features of the considered linear MPC are: (i) a virtual reference, to guarantee input constraints satisfaction, and (ii) an integrator state as a servo compensator, to reduce the steady-state error. Moreover, the real-time implementability is investigated using an experimental testbed with four CMGs in pyramidal configuration, where the capability of attitude control and the optimization solver for embedded systems are focused on. The effectiveness and the performance of the control system are shown in both simulations and experiments.

A Novel Oxidovanadium (IV)-Orotate Complex as an Alternative Antidiabetic Agent: Synthesis, Characterization, and Biological Assessments

Diabetes is an increasingly common metabolic disorder with high comorbidity and societal and personal costs. Insulin replacement therapy is limited by a lack of oral bioavailability. Recent studies suggest vanadium has therapeutic potential. A newly synthesized complex between oxidovanadium (IV) and orotic acid (OAH3), [(OAH1)(VO)(NH3)2].3H2O, was characterized using spectroscopic and thermogravimetric techniques. In vivo potential was assessed in a streptozocin-induced rat model of diabetes. OAH3 acts as a bidentate ligand in the formation of the dark green, crystalline oxidovanadium (IV) complex in a square pyramidal configuration. Treatment with oxidovanadium (IV)-orotate in vivo significantly improved many biochemical parameters with minimal toxicity and restored pancreatic and hepatic histology. The results of the present work describe a safe, new compound for the treatment of diabetes.

Design of new anti-Alzheimer drugs: ring-expansion synthesis and synchrotron X-ray diffraction study of dimethyl 4-ethyl-11-fluoro-1,4,5,6,7,8-hexahydroazonino[5,6-b]indole-2,3-dicarboxylate

The title compound, C20H23FN2O4, is the product of a ring-expansion reaction from a seven-membered fluorinated hexahydroazepine to a nine-membered azonine. The nine-membered azonine ring of the molecule adopts achair–boatconformation. The C=C and C—N bond lengths [1.366 (3) and 1.407 (3) Å, respectively] indicate the presence of conjugation within the enamine CH2—C=C—N—CH2fragment. The substituent planes at the C=C double bond of this fragment are twisted by 16.0 (3)° as a result of steric effects. The amine N(Et) N atom has a trigonal–pyramidal configuration (sum of the bond angles = 346.3°). The interplanar angle between the two carboxylate substituents is 60.39 (8)°. In the crystal, molecules form zigzag chains along [010] by intermolecular N—H...O hydrogen-bonding interactions, which are further packed in stacks toward [100]. The title azoninoindole might be considered as a candidate for the design of new Alzheimer drugs.

Exploitation of Large Recoverable Deformations Using Weaved Shape Memory Alloy Wire-Based Sandwich Panel Configurations

A new class of truss structure based on superelastic shape memory alloy (SMA) wire has been developed by weaving superelastic SMA wire through two perforated facesheets. A gap was maintained between the facesheets while weaving and the ends of wire forming the truss legs are anchored in each facesheet. The resulting structure has a modified pyramidal configuration and is capable of undergoing large recoverable deformations typical of superelastic SMA. A four-unit cell truss specimen has been tested under static load cycles to investigate the compressive response. The truss specimen underwent a hysteretic loop and demonstrated minimal permanent deformation closely resembling the behavior of bulk SMA. A finite element model of the truss was generated and the analysis results were compared with the experimental response. The present work is an attempt to demonstrate an SMA-based truss structure having energy absorption capabilities with minimum permanent deformation. These truss structures may be applied for damage mitigation in composites subjected to impact and blast loads.

A Non-Planar Iodinated Pyrrole Study

ABSTRACTNon-planar iodinated pyrrole structures were found through DFT calculations of geometry optimization, when doping one pyrrole molecule with iodine atoms. This take us to a new mono-iodinated pyrrole structure in which one pyrrole molecule is attacked with one iodine atom in a pyramidal configuration. Then, the pyrrole molecule was attacked with two and until four optimized linear iodine atoms in a pyramidal structure configuration. The corresponding potential energy curves were also constructed in order to know what kind of adsorption (physisorption or chemisorption) is obtained, considering physisorption as lower than ten kcal/mol, and chemisorption greater than twenty kcal/mol according to the literature. Finally, it is known that halogenated pyrrole is a highly conductive material required in several fields.

Crystal structure of {2-[({2-[(2-aminoethyl)amino]ethyl}imino)methyl]-6-hydroxyphenolato-κ4N,N′,N′′,O1}(nitrato-κO)copper(II) ethanol 0.25-solvate

In the crystal structure of the title mononuclear CuIIcomplex, [Cu(C11H16N3O2)(NO3)]·0.25C2H5OH, the complex molecules are linked by N—H...O and O—H...O hydrogen bonds, forming a dimer with an approximate non-crystallographic twofold rotation axis of symmetry. In the monomeric unit, the Cu2+ion exhibits a distorted square-pyramidal configuration, whereby the anionic [HL]−Schiff base ligand binds in a tetradentate fashionviathe O and the three N atoms which all are approximately coplanar. The O atom of a nitrate anion occupies the fifth coordination site, causing the CuIIatom to move slightly out of the approximate basal plane toward the bound nitrate group. The structure exhibits disorder of the ethanol solvent molecule.