2,564 research outputs found
Technology Diffusion, North-South Spillovers and Industrial Location
Relying on a model of economic geography, this paper discusses development opportunities arising from international trade and technology diffusion. We show that either import substitution or trade liberalization may trigger takeoff in the developing country, although these two policies work through different mechanisms. The industrialization process is also influenced by knowledge spillovers: strong international technology diffusion offers better prospects for the developing country to benefit from technological externalities provided abroad. Thus, one objective of the developing country should be to enhance its absorptive capacity in order to exploit these technological externalities. In this context, only import substitution trade policy seems to be successful in financing indigenous learning process. However, this result is strongly dependent on the effectiveness of budgetary resource allocation.
Positive psychology and tourism: a systematic literature review
This study aims to outline the relationship between Positive Psychology and tourism through a systematic literature review. Tourism seeks to increase the wellbeing of people, and wellbeing is a crucial variable in Positive Psychology which in turn aims to understand and promote people's potential. This research used as search terms 'Positive Psychology', 'wellbeing', 'happiness', 'tourism', 'visitor' and 'travel', terms which were applied through the Online Knowledge Library. The inclusion/exclusion criteria led to a sample of 49 references which were then individually analyzed. Results showed a recent increase in studies focused on the relationship between the variables, Europe being in the lead. Overall, policies are important for tourism development; tourism promotes wellbeing for residents and tourists; entrepreneurs have an innovative opportunity in wellbeing; and nature is linked to wellbeing. Implications and suggestions for future studies are presented.AgĂȘncia financiadora
ARDITI - AgĂȘncia Regional para o Desenvolvimento da Investigação Tecnologia e Inovação: M1420-09-5369-FSE-000001info:eu-repo/semantics/publishedVersio
Aspects of Countertrade and Development
Countertrade or international barter has enjoyed a flourish of activity during the 1980s. Some authors have suggested that countertrade is an effective development tool for third world countries and indeed represents the beginning of a rearrangement of the international economic order in favor of lesser developed. countries....On the other hand, others have suggested that countertrade is an aberration reflecting a misguided understanding of international trade and finance by LDC policymakers
Deployment of Deep Neural Networks on Dedicated Hardware Accelerators
Deep Neural Networks (DNNs) have established themselves as powerful tools for
a wide range of complex tasks, for example computer vision or natural language
processing. DNNs are notoriously demanding on compute resources and as a
result, dedicated hardware accelerators for all use cases are developed. Different
accelerators provide solutions from hyper scaling cloud environments for the
training of DNNs to inference devices in embedded systems. They implement
intrinsics for complex operations directly in hardware. A common example
are intrinsics for matrix multiplication. However, there exists a gap between
the ecosystems of applications for deep learning practitioners and hardware
accelerators. HowDNNs can efficiently utilize the specialized hardware intrinsics
is still mainly defined by human hardware and software experts.
Methods to automatically utilize hardware intrinsics in DNN operators are a
subject of active research. Existing literature often works with transformationdriven
approaches, which aim to establish a sequence of program rewrites and
data-layout transformations such that the hardware intrinsic can be used to
compute the operator. However, the complexity this of task has not yet been
explored, especially for less frequently used operators like Capsule Routing. And
not only the implementation of DNN operators with intrinsics is challenging,
also their optimization on the target device is difficult. Hardware-in-the-loop
tools are often used for this problem. They use latency measurements of implementations
candidates to find the fastest one. However, specialized accelerators
can have memory and programming limitations, so that not every arithmetically
correct implementation is a valid program for the accelerator. These invalid
implementations can lead to unnecessary long the optimization time.
This work investigates the complexity of transformation-driven processes to
automatically embed hardware intrinsics into DNN operators. It is explored
with a custom, graph-based intermediate representation (IR). While operators
like Fully Connected Layers can be handled with reasonable effort, increasing
operator complexity or advanced data-layout transformation can lead to scaling issues.
Building on these insights, this work proposes a novel method to embed
hardware intrinsics into DNN operators. It is based on a dataflow analysis.
The dataflow embedding method allows the exploration of how intrinsics and
operators match without explicit transformations. From the results it can derive
the data layout and program structure necessary to compute the operator with
the intrinsic. A prototype implementation for a dedicated hardware accelerator
demonstrates state-of-the art performance for a wide range of convolutions, while
being agnostic to the data layout. For some operators in the benchmark, the
presented method can also generate alternative implementation strategies to
improve hardware utilization, resulting in a geo-mean speed-up of Ă2.813 while
reducing the memory footprint. Lastly, by curating the initial set of possible
implementations for the hardware-in-the-loop optimization, the median timeto-
solution is reduced by a factor of Ă2.40. At the same time, the possibility to
have prolonged searches due a bad initial set of implementations is reduced,
improving the optimizationâs robustness by Ă2.35
A survey of student attitudes toward pocket-size paperback books
Thesis (Ed.M.)--Boston Universit
THE CELLULAR RECEPTOR (CD4) OF THE HUMAN IMMUNODEFICIENCY VIRUS IS EXPRESSED ON NEURONS AND GLIAL CELLS IN HUMAN BRAIN
The peculiar tropism of the human immunodeficiency virus (HIV) for T
helper lymphocytes can be explained by a specific interaction between the virus
and the CD4 molecule on these cells (1, 2). The tropism for T lymphocytes,
however, can hardly account for the early brain infection observed in some AIDS
(acquired immune deficiency syndrome) patients (3, 4). Since CD4 is also expressed
on virus-susceptible non-T cell lines we wondered whether an additional
expression site of CD4 could be demonstrated in neural tissue (5). To this end,
CD4 expression in brain was analyzed with several different anti-CD4 mAbs, and
using a CD4-specific cDNA probe in Northern blot analyses . CD4' cells and
CD4-specific mRNA were found in the cerebellum, thalamus, and pons. The
reactive cells could be identified as neurons as well as glial cells
M-DC8+leukocytes - A novel human dendritic cell population
Dendritic cells (DC) constitute a heterogeneous leukocyte population having in common a unique capacity to induce primary T cell responses and are therefore most attractive candidates for immunomodulatory strategies. Two populations of blood DC (CD11c+ CD123(dim) and CD11c- CD123(high)) have been defined so far. However, their direct isolation for experimental purposes is hampered by their low frequency and by the lack of selective markers allowing large scale purification from blood. Here we describe the monoclonal antibody (mAb) M-DC8, which was generated by immunizing mice with highly enriched blood DC. This mAb specifically reacts with 0.2-1% of blood leukocytes and enables their direct isolation by a one-step immunomagnetic procedure from fresh mononuclear cells. These cells can be differentiated from T cells, B cells, NK cells and monocytes using lineage-specific antibodies. M-DC8+ cells express HLA class It molecules, CD33 and low levers of the costimulatory molecules CD86 and CD40. Upon in vitro culture M-DC8+ cells spontaneously mature into cells with the phenotype of highly stimulatory cells as documented by the upregulation of HLA-DR, CD86 and CD40; in parallel CD80 expression is induced. M-DC8+ cells display an outstanding capacity to present antigen. In particular, they proved to be excellent stimulators of autologous mixed leukocyte reaction and to activate T cells against primary antigens such as keyhole limpet hemocyanin. Furthermore, they induce differentiation of purified allogeneic cytotoxic T cells into alloantigen-specific cytotoxic effector cells. While the phenotypical analysis reveals similarities with the two known blood DC populations, the characteristic expression of Fc gamma RIII (CD16) and the M-DC8 antigen clearly defines them as a novel population of blood DC. The mAb M-DC8 might thus be a valuable tool to determine circulating DC for diagnostic purposes and to isolate these cells for studies of antigen-specific T cell priming. Copyright (C) 2000 S. Karger AG, Basel
VH-RELATED IDIOTOPES DETECTED BY SITE-DIRECTED MUTAGENESIS
The function of the CD4 cell surface protein as
coreceptor on T helper lymphocytes and as receptor
for HIV makes this glycoprotein a prime target for
an immune intervention with mAb. A detailed understanding
of the structural determinants on the
therapeutic CD4 mAb that are involved in Ag binding
or are recognized by anti-idiotypic mAb (anti-Id)
may be important for designing antibodies with optimal
therapeutic efficacy. Seven anti-Id raised
against the CD4 mAb M-T310 were selected from a
large panel with the intention to obtain CD4 mimicking
structures with specificity foHr IV gp120. The
selected anti-Id did not reacwt ith other CDCspecific
mAb cross-blocking M-T310. Among these, mAb MT404,
although having the same L chain as M-T310
and a VH region sequence differing onlya t 14 amino
acid positions, was not recognized by the anti-Id. MT310
H chain complexed with the J558L L chain
reacted with all anti-Id, thus demonstrating that the
recognized idiotopes are located within the VH region.
To identify the idiotopes of M-T310 seen by
the anti-Id, variants of M-T404 containing one or
more of the M-T3 1 O-derived substitutions were generated
by oligonucleotide-directed mutagenesis.
The reactivity pattern of the mutant proteins with
the anti-Id demonstrated that the idiotopes reside
within the complementarity determining region
(CDR) 2 and CDR3 loops of the VH region. A major
idiotope was definebdy a single amino acid in CDR2
that was recognized by three anti-Id, whereas the
four other anti-Id reacted with determinants of
CDR3. Although the performed amino acid substitutions
did influence the Id recognition, Ag binding
was not significantly affected, suggesting that none
of the anti-Id can be considered as a mimicry of the
CD4 A
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