6,384 research outputs found
Troubling Signs for South African Democracy under the ANC
Thirteen years ago, South Africa underwent a peaceful transition from white minority rule to majority rule. Today, the country is a stable multiparty democracy. It has the largest and the most sophisticated economy in Africa, which generates almost 40 percent of all the wealth produced on the African continent south of the Sahara. The African National Congress government, which came to power in 1994, deserves credit for stabilizing the economy and returning it to a steady, albeit slow, growth path. The ANC's democratic record is less impressive. The government has transformed the state-owned South African Broadcasting Corporation into an ANC propaganda machine that has banned some of the government's most prominent critics from appearing on it. The culture of political correctness stifles public debate over the direction of South Africa's economic and social policies. Those who dare to criticize the government are often labeled as racist. Moreover, the ANC is considering new laws that would undermine judicial independence. It is increasingly apparent that the ANC wishes to dominate the social and institutional life of South Africa in the same way that it dominates the country's political life. Fortunately, the ANC continues to put great value on its international reputation and tends to be hypersensitive to international criticism. When the government does not act in accordance with the spirit of liberal democracy, members of international civil society groups, the diplomatic corps, and the business community should voice their concern. Constructive criticism could change the ANC's behavior and positively influence political developments in South Africa
The Rise of Populist Parties in Central Europe: Big Government, Corruption, and the Threat to Liberalism
Central Europe has grown freer and more prosperous since the collapse of communism. Yet liberal parties, which were responsible for bringing those advances about, are on the defensive. In the last year, liberals have suffered a number of electoral setbacks throughout the region. Some commentators saw the poor performance of the liberal parties as a sign of weakening public support for the free market, but public opinion polls in Central Europe show continued support for capitalism. Certainly, there is no widespread support for a return to economic dirigisme, which failed so spectacularly in the past. Rather, one of the most important reasons for public discontent with the political establishment is government corruption. The pervasiveness of corruption in Central Europe is partly attributable to the underdevelopment of civil society and the concomitant paucity of effective restraints on the conduct of the political class. Moreover, despite the tremendous progress toward economic freedom that Central European countries have made since the fall of communism, the role of the state in the economy remains large. The private sector is burdened with too many regulations, and governments continue to spend some 44 percent of the region's gross domestic product. To lessen the problem of corruption, the size and the scope of the state must be reduced
The False Promise of Gleneagles: Misguided Priorities at the Heart of the New Push for African Development
The Gleneagles Summit, for all its good intentions, gave rise to unrealistic expectations. The heavy emphasis on aid and debt relief made Western actions appear to be chiefly responsible for poverty alleviation in Africa. In reality, the main obstacles to economic growth in Africa rest with Africa's policies and institutions, such as onerous business regulations and weak protection of property rights. Africa remains the poorest and least economically free region on earth. The West should do all it can to help Africa integrate with the rest of the world. It should eliminate remaining restrictions on African exports and end Western farm subsidies. Africans, however, will have to make most of the changes needed to tackle African poverty
Materials dispersion and biodynamics project research
The Materials Dispersion and Biodynamics Project (MDBP) focuses on dispersion and mixing of various biological materials and the dynamics of cell-to-cell communication and intracellular molecular trafficking in microgravity. Research activities encompass biomedical applications, basic cell biology, biotechnology (products from cells), protein crystal development, ecological life support systems (involving algae and bacteria), drug delivery (microencapsulation), biofilm deposition by living organisms, and hardware development to support living cells on Space Station Freedom (SSF). Project goals are to expand the existing microgravity science database through experiments on sounding rockets, the Shuttle, and COMET program orbiters and to evolve,through current database acquisition and feasibility testing, to more mature and larger-scale commercial operations on SSF. Maximized utilization of SSF for these science applications will mean that service companies will have a role in providing equipment for use by a number of different customers. An example of a potential forerunner of such a service for SSF is the Materials Dispersion Apparatus (MDA) 'mini lab' of Instrumentation Technology Associates, Inc. (ITA) in use on the Shuttle for the Commercial MDAITA Experiments (CMIX) Project. The MDA wells provide the capability for a number of investigators to perform mixing and bioprocessing experiments in space. In the area of human adaptation to microgravity, a significant database has been obtained over the past three decades. Some low-g effects are similar to Earth-based disorders (anemia, osteoporosis, neuromuscular diseases, and immune system disorders). As new information targets potential profit-making processes, services and products from microgravity, commercial space ventures are expected to expand accordingly. Cooperative CCDS research in the above mentioned areas is essential for maturing SSF biotechnology and to ensure U.S. leadership in space technology. Currently, the MDBP conducts collaborative research with investigators at the Rockefeller University, National Cancer Institute, and the Universities of California, Arizona, and Alabama in Birmingham. The growing database from these collaborations provides fundamental information applicable to development of cell products, manipulation of immune cell response, bone cell growth and mineralization, and other processes altered by low-gravity. Contacts with biotechnology and biopharmaceutical companies are being increased to reach uninformed potential SSF users, provide access through the CMDS to interested users for feasibility studies, and to continue active involvement of current participants. We encourage and actively seek participation of private sector companies, and university and government researchers interested in biopharmaceuticals, hardware development and fundamental research in microgravity
Vector potential versus colour charge density in low-x evolution
We reconsider the evolution equations for multigluon correlators derived in
hep-ph/9709432. We show how to derive these equations directly in terms of
vector potentials (or colour field strength) avoiding the introduction of the
concept of colour charge density in the intermediate steps. The two step
procedure of deriving the evolution of the charge density correlators followed
by the solution of classical equations for the vector potentials is shown to be
consistent with direct derivation of evolution for vector potentials. In the
process we correct some computational errors of hep-ph/9709432 and present the
corrected evolution equations which have a somewhat simpler appearance.Comment: 15 pages, 1 figure, changes made referee report, to be published in
Phys. Rev
Nutrient requirements and other factors involved in the culture of human kidney cells on microcarrier beads
The culture of human kidney cells on microcarrier beads in the Bioprocessing Laboratory at the Johnson Space Center is described. These were the first series of studies performed before and during 1983 to determine optimum conditions, including medium type, bead type and density. The composition of several medium types and the molecular weights of some common culture medium supplements and cellular proteins are included. The microgravity cell-to-bead attachment experiment performed on Space Transportation System Flight 8 is described
The role of interstitial binding in radiation induced segregation in W-Re alloys
Due to their high strength and advantageous high-temperature properties,
tungsten-based alloys are being considered as plasma-facing candidate materials
in fusion devices. Under neutron irradiation, rhenium, which is produced by
nuclear transmutation, has been found to precipitate in elongated precipitates
forming thermodynamic intermetallic phases at concentrations well below the
solubility limit. Recent measurements have shown that Re precipitation can lead
to substantial hardening, which may have a detrimental effect on the fracture
toughness of W alloys. This puzzle of sub-solubility precipitation points to
the role played by irradiation induced defects, specifically mixed solute-W
interstitials. Here, using first-principles calculations based on density
functional theory, we study the energetics of mixed interstitial defects in
W-Re, W-V, and W-Ti alloys, as well as the heat of mixing for each
substitutional solute. We find that mixed interstitials in all systems are
strongly attracted to each other with binding energies of -2.4 to -3.2 eV and
form interstitial pairs that are aligned along parallel first-neighbor
strings. Low barriers for defect translation and rotation enable defect
agglomeration and alignment even at moderate temperatures. We propose that
these elongated agglomerates of mixed-interstitials may act as precursors for
the formation of needle-shaped intermetallic precipitates. This
interstitial-based mechanism is not limited to radiation induced segregation
and precipitation in W-Re alloys but is also applicable to other body-centered
cubic alloys.Comment: 8 pages, 7 figure
Shadowing of gluons in perturbative QCD: A comparison of different models
We investigate the different perturbative QCD-based models for nuclear
shadowing of gluons. We show that in the kinematic region appropriate to RHIC
experiment, all models give similar estimates for the magnitude of gluon
shadowing. At scales relevant to LHC, there is a sizable difference between
predictions of the different models.Comment: 11 pages, 4 figure
Network of social groups or Let's have a party
We present a simple model for growing up and depletion of parties due to the
permanent communication between the participants of the events. Because of the
rapid exchange of information, everybody is able to evaluate its own and and
all other parties by means of the list of its friends. Therefore the number of
participants at different parties can be changed incessantly. Depending on the
deepness of the social contacts, which will be characterized by a parameter
, a stable distribution of party members emerges. At a critical
an abrupt depletion of almost all parties is observed and as the
consequence all the peoples are assembled at a single party. The model is based
on a hierarchical social network. The probability that a certain person is
contacted to another one depends on the social distance introduced within the
network and homophily parameter .Comment: 15 pages, 6 figure
Computationally-efficient stochastic cluster dynamics method for modeling damage accumulation in irradiated materials
An improved version of a recently developed stochastic cluster dynamics (SCD)
method {[}Marian, J. and Bulatov, V. V., {\it J. Nucl. Mater.} \textbf{415}
(2014) 84-95{]} is introduced as an alternative to rate theory (RT) methods for
solving coupled ordinary differential equation (ODE) systems for irradiation
damage simulations. SCD circumvents by design the curse of dimensionality of
the variable space that renders traditional ODE-based RT approaches inefficient
when handling complex defect population comprised of multiple (more than two)
defect species. Several improvements introduced here enable efficient and
accurate simulations of irradiated materials up to realistic (high) damage
doses characteristic of next-generation nuclear systems. The first improvement
is a procedure for efficiently updating the defect reaction-network and event
selection in the context of a dynamically expanding reaction-network. Next is a
novel implementation of the -leaping method that speeds up SCD
simulations by advancing the state of the reaction network in large time
increments when appropriate. Lastly, a volume rescaling procedure is introduced
to control the computational complexity of the expanding reaction-network
through occasional reductions of the defect population while maintaining
accurate statistics. The enhanced SCD method is then applied to model defect
cluster accumulation in iron thin films subjected to triple ion-beam
(, and \text{H\ensuremath{{}^{+}}})
irradiations, for which standard RT or spatially-resolved kinetic Monte Carlo
simulations are prohibitively expensive
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