5,227 research outputs found
Electroweakino constraints from LHC data
We investigate the sensitivity of existing LHC searches to the charginos and
neutralinos of the MSSM when all the other superpartners are decoupled. In this
limit, the underlying parameter space reduces to a simple four-dimensional set
. We examine the constraints placed on this
parameter space by a broad range of LHC searches taking into account the full
set of relevant production and decay channels. We find that the exclusions
implied by these searches exceed existing limits from LEP only for smaller
values of the Bino mass GeV. Our results have implications
for MSSM dark matter and electroweak baryogenesis.Comment: 30 pages, 15 figure
Non-Thermal Dark Matter from Cosmic Strings
Cosmic strings can be created in the early universe during symmetry-breaking
phase transitions, such as might arise if the gauge structure of the standard
model is extended by additional U(1) factors at high energies. Cosmic strings
present in the early universe form a network of long horizon-length segments,
as well as a population of closed string loops. The closed loops are unstable
against decay, and can be a source of non-thermal particle production. In this
work we compute the density of WIMP dark matter formed by the decay of gauge
theory cosmic string loops derived from a network of long strings in the
scaling regime or under the influence of frictional forces. We find that for
symmetry breaking scales larger than 10^10 GeV, this mechanism has the
potential to account for the observed relic density of dark matter. For
symmetry breaking scales lower than this, the density of dark matter created by
loop decays from a scaling string network lies below the observed value. In
particular, the cosmic strings originating from a U(1) gauge symmetry broken
near the electroweak scale, that could lead to a massive Z' gauge boson
observable at the LHC, produce a negligibly small dark matter relic density by
this mechanism.Comment: 22 pages, 4 figures, added discussion about boosted decay products
from loop cusp
Forestry timber typing. Tanana demonstration project, Alaska ASVT
The feasibility of using LANDSAT digital data in conjunction with topographic data to delineate commercial forests by stand size and crown closure in the Tanana River basin of Alaska was tested. A modified clustering approach using two LANDSAT dates to generate an initial forest type classification was then refined with topographic data. To further demonstrate the ability of remotely sensed data in a fire protection planning framework, the timber type data were subsequently integrated with terrain information to generate a fire hazard map of the study area. This map provides valuable assistance in initial attack planning, determining equipment accessibility, and fire growth modeling. The resulting data sets were incorporated into the Alaska Department of Natural Resources geographic information system for subsequent utilization
An evaluation of thematic mapper simulator data for the geobotanical discrimination of rock types in Southwest Oregon
Rock type identification may be assisted by the use of remote sensing of associated vegetation, particularly in areas of dense vegetative cover where surface materials are not imaged directly by the sensor. The geobotanical discrimination of ultramafic parent materials was investigated and analytical techniques for lithologic mapping and mineral exploration were developed. The utility of remotely sensed data to discriminate vegetation types associated with ultramafic parent materials in a study area in southwest Oregon were evaluated. A number of specific objectives were identified, which include: (1) establishment of the association between vegetation and rock types; (2) examination of the spectral separability of vegetation types associated with rock types; (3) determination of the contribution of each TMS band for discriminating vegetation associated with rock types and (4) comparison of analytical techniques for spectrally classifying vegetation
State Courts Reject Leon on State Constitutional Grounds: A Defense of Reactive Rulings
In 1984, the United States Supreme Court announced a broad exception to the federal exclusionary rule\u27 in United States v. Leon. The Court held the exclusionary rule inapplicable when police officers obtain evidence in reasonable, good faith reliance on a warrant later found to be defective. Commentators had advised against the creation of the so-called good faith exception before Leon. After Leon, they promulgated a torrent of commentary criticizing both the Leon Court\u27s reasoning and its result. Today, because Leon does not control state constitutional decisions, the battle over the good faith exception is fought on the state level. Currently, the highest courts of eight states have rejected the Leon exception on state constitutional grounds, representing one of the latest accomplishments of the new federalism movement
The Gulf of California as a Large Marine Ecosystem
Large marine regions characterized by unique bathymetry, hydrography and productivity, within which marine populations have adapted reproductive, growth, and feeding strategies constitute large marine ecosystems (LME) (Sherman and Alexander, 1986). The Gulf of California a semi-enclosed sea off the western coast of Mexico qualifies as a LME as it presents physical and biological characteristics not found in the adjoining Pacific. This area sustains the largest commercial fishery in the country which is the sardine fishery. the sardine population resident in the Gulf of California has coupled its reproductive and migration strategies to the environment of this region. Fluctuations of the sardine stock in the Gulf of California are caused by environmental changes and human activities within the Gulf. This paper presents the major physical and biological components of the Gulf of California and identifies the major source of change for the sardine fishery found in this LME
Rethinking the Virtual University
This paper explores why the virtual university movement may be entering a new phase of development. This phase is characterized by inter-university coalitions that share information and communication technology (ICT) platforms to develop and deliver web-based courses. This collaborative movement is the result of a number of forces driven primarily by the need to address escalating ICT costs and overcome resistance of faculty to distance education initiatives. Complementary resources such as national library databases; Internet-based course materials; low cost, broadband communications; Internet2; and state legislative initiatives are additional drivers facilitating the move toward a collaborative virtual university (CVU) model. This model is examined as a change agent for universities to reexamine their individual roles in leveraging Internet resources to enhance the quality of higher education programs. Leading edge initiatives are also described
Just another meeting?: Investigating mentoring for early childhood teachers in Victoria
IN A TIME OF REFORM FOR children’s services in Australia, this paper explores the currentmentoring programs on offer to the early childhood sector in the state of Victoria. Thecommissioned research involved the mapping of existing mentoring programs, supported byan extensive literature review. A thematic analysis of the data identified the following aspectsas impacting on the success of the programs: the value placed on mentoring; the mentor’s role;the level of support and training for mentors; the availability of resources; the divisions betweenmentoring and other management functions; tailoring of mentoring to individual professionaldesires and needs; and the presence or absence of formal evaluations to inform the futuresuccess of programs. The questions raised by this research prompt further consideration as towhat mentoring for early childhood practitioners should look like in the future, especially relatedto collaborative practice and the balance between autonomy and guidance
Batterer intervention program facilitators\u27 perceptions of the efficacy of current behavior intervention models
This qualitative study explored the question: Is the extensive use of the Duluth Model in the treatment of perpetrators of domestic violence and its derivatives based on perceived efficacy among the facilitators of these programs, or is there a more effective model that is suggested based upon their experiences? A flexible research design was utilized in order to explore the experience of 12 Batterer Intervention Program (BIP) facilitators through the process of in depth, individual interviews. The major themes identified were the facilitators\u27 need for change in the interventions utilized, their experience of powerlessness within their field, and their desire for greater community support to hold perpetrators accountable and affect change in their behavior. Among the facilitators interviewed, there was a predominant opinion that an intervention which expands upon existing Duluth based BIP methodology would be more successful in changing batterer behaviors
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