From monoclonal antibody to gene for a neuron-specific glycoprotein in Drosophila

A monoclonal antibody (MAb24B10), derived from mice immunized with Drosophila retina, exclusively stains photoreceptor cells in the retina and their axonal projections to the optic ganglia. The antigen (Ag24B10) is a 160-kDa glycoprotein comprising about 0.8% of the retina protein. By microsequencing, 19 of the first 21 amino acids at the NH2-terminal end of the protein have been determined. Using synthetic oligonucleotide probes corresponding to a portion of this amino acid sequence, we isolated a homologous genomic clone. A partial DNA sequence of this clone, along with blot experiments on genomic DNA and RNA, indicate that this clone is part of the structural gene for Ag24B10. By in situ hybridization, the gene was localized to the tip of chromosome 3R

Control of multiple tele-operated Robotic Bridge Transporters for remote handling of hazardous material

The objective of this research is to develop control of a multiple telerobot system based on Direct Numerical Processing Technology and propose a practically implementable collision avoidance algorithm for two gantry type robots sharing a common workspace; The tele-operatic set-up consists of two Robotic Bridge Transporters which are X-Y-Z positioning overhead bridge type cranes. These cranes consisting of three sub-assemblies for the X, Y and Z motions respectively are actuated by brushless servo drive motors. The DC motors are controlled by Modicon FA3240 automation controllers from a supervisory control station equipped with computer graphics based human-machine interface. Teleoperation is achieved through a programmable logic controller which acts as a command arbiter and data interface between the automation controllers and the supervisory control station computer; The collision avoidance algorithm proposes a collision free approach for a given path, by means of a minimum delay time technique for the two robots. Two examples, one each for a single segment and a two segment path for the two robots were tried out and found to work satisfactorily. The same can be extended to several segments as may be needed. The implementation methodology has been discussed

A model driven approach to building implementable model transformations.

The OMG's Model Driven Architecture (MDA) initiative has been the focus of much attention in both academia and industry, due to its promise of more rapid and consistent software development through the increased use of models. In order for MDA to reach its full potential, the ability to manipulate and transform models { most obviously from the Platform Independent Model (PIM) to the Platform Specic Models (PSM) { is vital. Recognizing this need, the OMG issued a Request For Proposals (RFP) largely concerned with nding a suitable mechanism for trans- forming models. This paper outlines the relevant background material, summarizes the approach taken by the QVT-Partners (to whom the authors belong), presents a non-trivial example using the QVT-Partners approach, and nally sketches out what the future holds for model transformations

A model driven approach to model transformations.

The OMG's Model Driven Architecture (MDA) initiative has been the focus of much attention in both academia and industry, due to its promise of more rapid and consistent software development through the increased use of models. In order for MDA to reach its full potential, the ability to manipulate and transform models { most obviously from the Platform Independent Model (PIM) to the Platform Specic Models (PSM) { is vital. Recognizing this need, the OMG issued a Request For Proposals (RFP) largely concerned with nding a suitable mechanism for trans- forming models. This paper outlines the relevant background material, summarizes the approach taken by the QVT-Partners (to whom the authors belong), presents a non-trivial example using the QVT-Partners approach, and finally sketches out what the future holds for model transformations

A pattern based model driven approach to model transformations.

The OMG's Model Driven Architecture (MDA) initiative has been the focus of much attention in both academia and industry, due to its promise of more rapid and consistent software development through the increased use of models. In order for MDA to reach its full potential, the ability to manipulate and transform models { most obviously from the Platform Independent Model (PIM) to the Platform Specic Models (PSM) { is vital. Recognizing this need, the OMG issued a Request For Proposals (RFP) largely concerned with nding a suitable mechanism for trans- forming models. This paper outlines the relevant background material, summarizes the approach taken by the QVT-Partners (to whom the authors belong), presents a non-trivial example using the QVT-Partners approach, and nally sketches out what the future holds for model transformations

Optimized Broadcast for Deep Learning Workloads on Dense-GPU InfiniBand Clusters: MPI or NCCL?

Dense Multi-GPU systems have recently gained a lot of attention in the HPC arena. Traditionally, MPI runtimes have been primarily designed for clusters with a large number of nodes. However, with the advent of MPI+CUDA applications and CUDA-Aware MPI runtimes like MVAPICH2 and OpenMPI, it has become important to address efficient communication schemes for such dense Multi-GPU nodes. This coupled with new application workloads brought forward by Deep Learning frameworks like Caffe and Microsoft CNTK pose additional design constraints due to very large message communication of GPU buffers during the training phase. In this context, special-purpose libraries like NVIDIA NCCL have been proposed for GPU-based collective communication on dense GPU systems. In this paper, we propose a pipelined chain (ring) design for the MPI_Bcast collective operation along with an enhanced collective tuning framework in MVAPICH2-GDR that enables efficient intra-/inter-node multi-GPU communication. We present an in-depth performance landscape for the proposed MPI_Bcast schemes along with a comparative analysis of NVIDIA NCCL Broadcast and NCCL-based MPI_Bcast. The proposed designs for MVAPICH2-GDR enable up to 14X and 16.6X improvement, compared to NCCL-based solutions, for intra- and inter-node broadcast latency, respectively. In addition, the proposed designs provide up to 7% improvement over NCCL-based solutions for data parallel training of the VGG network on 128 GPUs using Microsoft CNTK.Comment: 8 pages, 3 figure

Succinct Indexable Dictionaries with Applications to Encoding kk-ary Trees, Prefix Sums and Multisets

We consider the {\it indexable dictionary} problem, which consists of storing a set $S \subseteq \{0,...,m-1\}$ for some integer $m$, while supporting the operations of \Rank(x), which returns the number of elements in $S$ that are less than $x$ if $x \in S$, and -1 otherwise; and \Select(i) which returns the $i$-th smallest element in $S$. We give a data structure that supports both operations in O(1) time on the RAM model and requires ${\cal B}(n,m) + o(n) + O(\lg \lg m)$ bits to store a set of size $n$, where {\cal B}(n,m) = \ceil{\lg {m \choose n}} is the minimum number of bits required to store any $n$-element subset from a universe of size $m$. Previous dictionaries taking this space only supported (yes/no) membership queries in O(1) time. In the cell probe model we can remove the $O(\lg \lg m)$ additive term in the space bound, answering a question raised by Fich and Miltersen, and Pagh. We present extensions and applications of our indexable dictionary data structure, including: An information-theoretically optimal representation of a $k$-ary cardinal tree that supports standard operations in constant time, A representation of a multiset of size $n$ from $\{0,...,m-1\}$ in ${\cal B}(n,m+n) + o(n)$ bits that supports (appropriate generalizations of) \Rank and \Select operations in constant time, and A representation of a sequence of $n$ non-negative integers summing up to $m$ in ${\cal B}(n,m+n) + o(n)$ bits that supports prefix sum queries in constant time.Comment: Final version of SODA 2002 paper; supersedes Leicester Tech report 2002/1

Manuscrits lul·lians de la Biblioteca de Catalunya. I

We have studied the correlates of cell death during stalk cell differentiation in Dictyostelium discoideum. Our main findings are four. (i) There is a gradual increase in the number of cells with exposed phosphatidyl serine residues, an indicator of membrane asymmetry loss and increased permeability. Only presumptive stalk cells show this change in membrane asymmetry. Cells also show an increase in cell membrane permeability under conditions of calcium-induced stalk cell differentiation in cell monolayers. (ii) There is a gradual fall in mitochondrial membrane potential during development, again restricted to the presumptive stalk cells. (iii) The fraction of cells showing caspase-3 activity increases as development proceeds and then declines in the terminally differentiated fruiting body. (iv) There is no internucleosomal cleavage of DNA, or DNA fragmentation, in D. discoideum nor is there any calcium- and magnesium-dependent endonucleolytic activity in nuclear extracts from various developmental stages. However, nuclear condensation and peripheralization does occur in stalk cells. Thus, cell death in D. discoideum shows some, but not all, features of apoptotic cell death as recognized in other multicellular systems. These findings argue against the emergence of a single mechanism of 'programmed cell death (PCD)' before multicellularity arose during evolution

Preliminary results on the simulation of the 1999 Orissa supercyclone using a GCM with a new boundary layer code

We present here preliminary results from the simulation of the Orissa supercyclone using a new AGCM code (named Varsha) written as part of a NMITLI project. The simulation is initialized at 00 UTC, 26 October 1999, using ECMWF T-106 initial conditions. The control run is made using the Varsha code at a T-80 resolution with a standard Monin-Obukhov boundary layer code incorporating a gustiness factor. With the horizontal resolution improved to 120 spectral modes with a 78 km grid spacing, and a new boundary layer parameterization at low winds, the code shows substantial improvements: the maximum error is reduced from 350 to 234 km at 36 h after initialization, 310 to 34 km at 48 h, and 410 to 55 km at 96 h. It is suggested that part of the explanation for this improvement lies in the improved estimation of surface forces and torque in the new boundary layer code. The role of torque is particularly interesting as the major contribution to it comes from the outer regions of the cyclone where the winds are relatively low but the area on which the surface force acts and its moment arm are both high. Intriguingly the higher surface forces arise also from the higher winds predicted by the new code. An interesting finding is that, on both track and minimum pressure, the improvement due to higher resolution is greater with the new boundary layer module. Further analysis is necessary to assess the effect of other eddy fluxes (sensible heat, moisture) on cyclone track prediction