239 research outputs found
R-Parity Violation at the LHC
We investigate the phenomenology of the MSSM extended by a single R-parity
violating coupling at the unification scale. For all R-parity violating
couplings, we discuss the evolution of the particle spectra through the
renormalization group equations and the nature of the lightest supersymmetric
particle (LSP) within the CMSSM, as an example of a specific complete
supersymmetric model. We use the nature of the LSP to classify the possible
signatures. For each possible scenario we present in detail the current LHC
bounds on the supersymmetric particle masses, typically obtained using
simplified models. From this we determine the present coverage of R-parity
violating models at the LHC. We find several gaps, in particular for a
stau-LSP, which is easily obtained in R-parity violating models. Using the
program CheckMATE we recast existing LHC searches to set limits on the
parameters of all R-parity violating CMSSMs. We find that virtually all of them
are either more strongly constrained or similarly constrained in comparison to
the R-parity conserving CMSSM, including the models. For
each R-parity violating CMSSM we then give the explicit lower mass bounds on
all relevant supersymmetric particles.Comment: 43 pages, 13 tables, 17 figures; updated Figs. 11-17 and Tab. 12
including NLO corrections; version accepted for publication in EPJ
Automatically controlled deficit irrigation of lettuce in “organic potponics”
Concerns with water crisis involve all sectors of society and irrigated agriculture remains the main water consumer. This study evaluated an agricultural production system for lettuce cultivation in greenhouse, “organic potponics”, to economize water and manure use, using a Simplified Irrigation Controller (SIC), based on soil matric potential monitoring. Five irrigation volumes were evaluated in pots with 4.8 L, fertilized with 200 g of vermicompost. One of the volumes was controlled with the SIC. The other volumes represented 130, 80, 60 and 33 % of that controlled by the SIC and all treatments received water at the same time. Shoot fresh weight, head diameter and stomatal conductance (gs) increased linearly with irrigation volumes. For shoot dry weight, number of leaves and water use efficiency (WUE), the regression was quadratic with maximum values at 126, 114 and 83 %, respectively. Leaf relative water content did not show variation among treatments and changes in some fluorescence parameters (Reo/RC, Sm, N and φR0) were much more remarkable to drought compared with the FV/ FM ratio, one of the most commonly used stress indicators. The data indicated a tradeoff between WUE and plant growth thus the economic values of water and lettuce should be taken into account to indicate the best SIC irrigation volume. Organic potponics is promising and should be further improved to save on water, labor and fertilizer use
Chytridiomycosis and Amphibian Population Declines Continue to Spread Eastward in Panama
Chytridiomycosis is a globally emerging disease of amphibians and the leading cause of population declines and extirpations at species-diverse montane sites in Central America. We continued long-term monitoring efforts for the presence of the fungal pathogen Batrachochytrium dendrobatidis (Bd) and for amphibian populations at two sites in western Panama, and we began monitoring at three new sites to the east. Population declines associated with chytridiomycosis emergence were detected at Altos de Campana National Park. We also detected Bd in three species east of the Panama Canal at Soberanía National Park, and prevalence data suggests that Bd may be enzootic in the lowlands of the park. However, no infected frogs were found further east at Tortí (prevalence <7.5% with 95% confidence). Our results suggest that Panama's diverse and not fully described amphibian communities east of the canal are at risk. Precise predictions of future disease emergence events are not possible until factors underlying disease emergence, such as dispersal, are understood. However, if the fungal pathogen spreads in a pattern consistent with previous disease events in Panama, then detection of Bd at Tortí and other areas east of the Panama Canal is imminent. Therefore, development of new management strategies and increased precautions for tourism, recreation, and biology are urgently neede
Uma Proposta de Implantação do Pensamento Interdisciplinar em Cursos de Graduação em Administração.
Apesar de praticamente todo projeto pedagógico de curso de graduação em administração admitir que a interdisciplinaridade é o que a caracterização enquanto Ciência, não há um esquema metodológico capaz de permitir o gerenciamento adequado desses cursos em consonância com dimensão conceitual interdisciplinar. Assim, paradoxalmente, enquanto ciência interdisciplinar, a Administração é trabalhada disciplinarmente e, consequentemente, os administradores perdem aquilo que é seu diferencial, ou seja, a capacidade de compreender os fatos e fenômenos do mundo tal qual eles são, em perspectivas diferentes integradas. Este artigo tem como objetivo apresentar uma proposta de implementação do pensamento e ação interdisciplinares em cursos de graduação em administração a partir da sua relação com as atividades de investigação científica. Essa aliança reforça no graduando a compreensão da essencialidade de procedimentos racionais e metodológicos para a explicação da realidade assim como o uso do princípio da racionalidade no processo de tomada de decisão gerencial
Introducing a nationwide registry: the Swiss study on aneurysmal subarachnoid haemorrhage (Swiss SOS)
Background: Aneurysmal subarachnoid haemorrhage (aSAH) is a haemorrhagic form of stroke and occurs in a younger population compared with ischaemic stroke or intracerebral haemorrhage. It accounts for a large proportion of productive life-years lost to stroke. Its surgical and medical treatment represents a multidisciplinary effort. Due to the complexity of the disease, the management remains difficult to standardise and quality of care is accordingly difficult to assess. Objective: To create a registry to assess management parameters of patients treated for aSAH in Switzerland. Methods: A cohort study was initiated with the aim to record characteristics of patients admitted with aSAH, starting January 1st 2009. Ethical committee approval was obtained or is pending from the institutional review boards of all centres. In the study period, seven Swiss hospitals (five university [U], two non-university medical centres) harbouring a neurosurgery department, an intensive care unit and an interventional neuroradiology team so far agreed to participate in the registry (Aarau, Basel [U], Bern [U], Geneva [U], Lausanne [U], St. Gallen, Zürich [U]). Demographic and clinical parameters are entered into a common database. Discussion: This database will soon provide (1) a nationwide assessment of the current standard of care and (2) the outcomes for patients suffering from aSAH in Switzerland. Based on data from this registry, we can conduct cohort comparisons or design diagnostic or therapeutic studies on a national level. Moreover, a standardised registration system will allow healthcare providers to assess the quality of car
Invasive Streptococcus pneumoniae in Children, Malawi, 2004–2006
Of 176 invasive Streptococcus pneumoniae isolates from children in Malawi, common serotypes were 1 (23%), 6A/B (18%), 14 (6%), and 23F (6%). Coverage with the 7-valent pneumococcal conjugate vaccine (PCV) was 39%; PCV10 and PCV13 increased coverage to 66% and 88%, respectively. We found chloramphenicol resistance in 27% of isolates and penicillin nonsusceptibility in 10% (by using meningitis breakpoints); all were ceftriaxone susceptible
Interference in interacting quantum dots with spin
We study spectral and transport properties of interacting quantum dots with
spin. Two particular model systems are investigated: Lateral multilevel and two
parallel quantum dots. In both cases different paths through the system can
give rise to interference. We demonstrate that this strengthens the multilevel
Kondo effect for which a simple two-stage mechanism is proposed. In parallel
dots we show under which conditions the peak of an interference-induced orbital
Kondo effect can be split.Comment: 8 pages, 8 figure
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
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