Caldesmon regulates actin dynamics to influence cranial neural crest migration in Xenopus

Caldesmon (CaD) is an important actin modulator that associates with actin filaments to regulate cell morphology and motility. Although extensively studied in cultured cells, there is little functional information regarding the role of CaD in migrating cells in vivo. Here we show that nonmuscle CaD is highly expressed in both premigratory and migrating cranial neural crest cells of Xenopus embryos. Depletion of CaD with antisense morpholino oligonucleotides causes cranial neural crest cells to migrate a significantly shorter distance, prevents their segregation into distinct migratory streams, and later results in severe defects in cartilage formation. Demonstrating specificity, these effects are rescued by adding back exogenous CaD. Interestingly, CaD proteins with mutations in the Ca^(2+)-calmodulin–binding sites or ErK/Cdk1 phosphorylation sites fail to rescue the knockdown phenotypes, whereas mutation of the PAK phosphorylation site is able to rescue them. Analysis of neural crest explants reveals that CaD is required for the dynamic arrangements of actin and, thus, for cell shape changes and process formation. Taken together, these results suggest that the actin-modulating activity of CaD may underlie its critical function and is regulated by distinct signaling pathways during normal neural crest migration

The Lens Condition with Two Factors

We give a simple, constructive proof that the lens condition implies the factor-price equalization condition, when there are only two factors. Taking stock of the sufficient conditions under which the lens condition implies the FPE condition, we have the conditions of two factors or two goods or two countries or the condition that the rank of the factor-use matrix is equal to the number of goods. We show that in an essential sense, there are no other such conditions.Lens Condition, Factor Price Equalization

Myosin-X is critical for migratory ability of Xenopus cranial neural crest cells

The neural crest is a highly migratory cell population, unique to vertebrates, that forms much of the craniofacial skeleton and peripheral nervous system. In exploring the cell biological basis underlying this behavior, we have identified an unconventional myosin, myosin-X (Myo10) that is required for neural crest migration. Myo10 is highly expressed in both premigratory and migrating cranial neural crest (CNC) cells in Xenopus embryos. Disrupting Myo10 expression using antisense morpholino oligonucleotides leads to impaired neural crest migration and subsequent cartilage formation, but only a slight delay in induction. In vivo grafting experiments reveal that Myo10-depleted CNC cells migrate a shorter distance and fail to segregate into distinct migratory streams. Finally, in vitro cultures and cell dissociation–reaggregation assays suggest that Myo10 may be critical for cell protrusion and cell–cell adhesion. These results demonstrate an essential role for Myo10 in normal cranial neural crest migration and suggest a link to cell–cell interactions and formation of processes

A low-cost Lactobacillus salivarius L29 growth medium containing molasses and corn steep liquor allows the attainment of high levels of cell mass and lactic acid production

The aim of the present work was to formulate a Lactobacillus salivarius L29 industrial fermentation medium. High cell numbers and good levels of lactic acid by a L. salivarius L29 were obtained after shake flask fermentation using molasses as the sole carbon source and corn steep liquor (CSL (industrial grade); an organic source of N) as the principal nitrogen source. The optimum concentrations of molasses and CSL facilitating good cell growth and high-level lactic acid production were found to be 6 and 6% (both v/v), respectively. The maximum cell yield was 2.02 × 109 CFU/mL, thus about 15% lower than that obtained when MRS broth was employed for 5-L fermenters culture. Lactic acid production upon growth in industrial broth was 105 g/L; the total sugar content of the medium was 118 g/L (sucrose: glucose: fructose 68:14:18; w/w/w). Upon growth in De Man, Rogosa and Sharpe (MRS) broth (the total sugar content of which was 127 g/L, all of which was glucose), the lactic acid yield was 120 g/L. The optimized industrial growth medium was significantly more economical than were conventional broths.Keywords: Lactobacillus salivarius L29, molasses, corn steep liquor, culture medium optimization, lactic acidAfrican Journal of Biotechnology Vol. 12(16), pp. 2013-201

Porting an application framework to the X Window System using the X Library

The Oregon Speedcode Universe v3.0 (OSU v3.0) has a class hierarchy designed and implemented to be portable to other platforms because there are few operating system dependent routines used in it. What needed to be ported were the 46 Application Framework Classes (Application Framework) and the 15 Shape Classes (Shape Class Library) that together used about 180 Macintosh Toolbox routines. Most of these Macintosh Toolbox routines are drawing primitives which are relatively easy to port. Some routines are more sophisticated, and they are tedious to mimic. The rest are extremely difficult to port because many platforms do not support these functionalities. It is well known that porting a GUI application to another system is very costly because a thorough understanding of both systems is required. We designed OSU v3.0 to be as portable as possible by 1) limiting the use of operating system dependent routines to the Application Framework and the Shape Class Library, and 2) using as few operating system dependent routines as possible. Then we ported 140 Macintosh Toolbox routines to the X Window System using the X Library (XLib) toolkit. The X Window System was chosen because 1) it is a standard window environment [Nye 90], 2) the XLib guarantees portability across various X workstations, 3) the XLib is available to all users, and 4) the XLib provides most of the routines we need, and it enables us to mimic the functionalities of the Macintosh Toolbox routines. This report describes the porting of 34 Macintosh Toolbox routines in 6 modules making up a total of 5386 lines of C code and 132 Kbytes of object code. The result is encouraging: using the portable Application Framework and the library of ported Toolbox routines (Portable Toolbox Library), an example application on the Macintosh was ported to the X window system by just transferring files and recompiling. The main contribution of this project is that it proves the portability of the Application Framework. It also provides an insight into the complication and feasibility of porting more Macintosh Toolbox routines to X Window System or other platforms. In addition, it was pointed out that applications developed in OSU v3.0 were partially portable [Keh 91]. Therefore, when the most frequently used Macintosh Toolbox routines are ported to the X Window System, applications developed in OSU v3.0 will become portable with little or no modification or costs

Automated Scenario Generation for Human-in-the-Loop Simulations

Automated Multi-Aircraft Control System scenario generation for Human-in-the-Loop (HITL) evaluations of air traffic management concepts is described. The objective is to replace the difficult manual process with the automated process for creating an initial (seed) scenario that serves as a starting point for manual adjustments for creating the Human-in-the-Loop scenario. Methods for analyzing and comparing the seed-scenario generated using the automated process and the Human-in-the-Loop-scenario derived from it to meet the experiment objectives are discussed. Results of comparison of input Human-in-the-Loop-scenario with the Multi-Aircraft Control System output are also presented. The main findings are: (1) many of the characteristics of the seed-scenario used for constructing the Human-in-the-Loop-scenario are preserved in the Human-in-the-Loop-scenario, (2) landing rate profile of the traffic generated by the Multi-Aircraft Control System (MACS) using the input scenario compares reasonably well with that intended in the input scenario, and (3) many of the desired characteristics of the Human-in-the-Loop-scenario can be achieved by further automation

Erratum

Erratum." Journal of Civil Engineering and Management, 23(5), p. 67

Steel beam–column joint with discontinuous vertical reinforcing bars

The authors have previously proposed steel beam–column connections for precast concrete frames. The steel–concrete composite frames combined the advantages of the fast assembly of steel and the low cost of concrete structures. However, when not enough space is available at column–beam joints, steel sections from beams cannot be connected with column brackets. To address this issue, this paper explores the strategy of disconnecting some vertical reinforcing bars at the joints by connecting vertical steel reinforcements to steel plates placed above and below column steels, to provide a load transfer path. Loads from re-bars are transferred to steel plates, column steels, and back to steel plates and re-bars below the column steels. This strategy provided space for beam–column joints of composite frames. Extensive experiments were performed to verify load transfer from re-bars to steel plates above joints and from the steel plates to re-bars below the joint. The flexural load-bearing capacity of a column with a total of 24 vertical re-bars was compared to that of columns with discontinuous re-bars at the joints; the number of discontinuous re-bars at the joint used in the column specimens tested was 0 (0.0%), 4 (16.7%), 12 (50.0%), and 20 (83.3%)