3,203 research outputs found
New bryophyte taxon records for tropical countries 1
This is the first in a series of papers listing new records, which will be published whenever sufficient new records have been found. The taxa are arranged by countries for an easier evaluation, e.g. updates of checklists. The initials of the contributor for each record is shown in square brackets after the record, and these initials are interpreted at the end of the paper
Bryophytes of Uganda : 2., new and interesting records
51 hepatics and 46 mosses are reported new to Uganda, including one moss new to Africa, one hepatic and two mosses new to mainland Africa, and 2 hepatics that are otherwise known only from their type collection
The prediction and management of aquatic nitrogen pollution across Europe: an introduction to the Integrated Nitrogen in European Catchments project (INCA)
Excess nitrogen in soils, fresh water, estuarine and marine systems contributes to nutrient enrichment in key ecosystems throughout Europe, often leading to detrimental environmental impacts, such as soil acidification or the eutrophication of water bodies. The Integrated Nitrogenmodel for European Catchments (INCA) project aims to develop a generic version of the Integrated Nitrogen in Catchments (INCA) model to simulate the retention and transport of nitrogen within river systems, thereby providing a tool to aid the understanding of nitrogen dynamics and for river-basin management/policy-making. To facilitate the development of the model, 10 partners have tested the INCA model with data collected in study sites located in eight European countries as part of the INCA project. This paper summarises the key nitrogen issues within Europe, describes the main aims and methodology of the INCA project, and sets the project in the context of the current major research initiatives at a European level.</p> <p style='line-height: 20px;'><b>Keywords: </b>Europe, European Union, nitrogen, nitrate, ammonium, river basin management, modelling, water chemistry, acidification, eutrophication, Water Framework Directive, INCA
A simple method for the determination of the structure of ultrashort relativistic electron bunches
In this paper we propose a new method for measurements of the longitudinal
profile of 100 femtosecond electron bunches for X-ray Free Electron Lasers
(XFELs). The method is simply the combination of two well-known techniques,
which where not previously combined to our knowledge. We use seed 10-ps 1047 nm
quantum laser to produce exact optical replica of ultrafast electron bunches.
The replica is generated in apparatus which consists of an input undulator
(energy modulator), and the short output undulator (radiator) separated by a
dispersion section. The radiation in the output undulator is excited by the
electron bunch modulated at the optical wavelength and rapidly reaches 100
MW-level peak power. We then use the now-standard method of ultrashort laser
pulse-shape measurement, a tandem combination of autocorrelator and spectrum
(FROG -- frequency resolved optical gating). The FROG trace of the optical
replica of electron bunch gives accurate and rapid electron bunch shape
measurements in a way similar to a femtosecond oscilloscope. Real-time
single-shot measurements of the electron bunch structure could provide
significant information about physical mechanisms responsible for generation
ultrashort electron bunches in bunch compressors. The big advantage of proposed
technique is that it can be used to determine the slice energy spread and
emittance in multishot measurements. It is possible to measure bunch structure
completely, that is to measure peak current, energy spread and transverse
emittance as a function of time. We illustrate with numerical examples the
potential of the proposed method for electron beam diagnostics at the European
X-ray FEL.Comment: 41 pages, 18 figure
Improving the scalability of parallel N-body applications with an event driven constraint based execution model
The scalability and efficiency of graph applications are significantly
constrained by conventional systems and their supporting programming models.
Technology trends like multicore, manycore, and heterogeneous system
architectures are introducing further challenges and possibilities for emerging
application domains such as graph applications. This paper explores the space
of effective parallel execution of ephemeral graphs that are dynamically
generated using the Barnes-Hut algorithm to exemplify dynamic workloads. The
workloads are expressed using the semantics of an Exascale computing execution
model called ParalleX. For comparison, results using conventional execution
model semantics are also presented. We find improved load balancing during
runtime and automatic parallelism discovery improving efficiency using the
advanced semantics for Exascale computing.Comment: 11 figure
Infectious disease outbreaks and increased complexity of care
Aim: This study examined the effects of healthcare-associated infectious disease outbreaks on nurses’ work in a large acute care hospital in Ontario, Canada.
Background: The incidence of healthcare-associated infections has increased. Previous research focuses on epidemiology, healthcare systems, and the economic burden of outbreaks. Few published studies focus on the impact of outbreaks on nurses’ work in acute care facilities.
Introduction: Since the severe acute respiratory syndrome epidemic in 2003, combating infectious diseases has become a key issue. Hospitals have implemented measures related to healthcare-associated infections. However, nurses experience challenges in preventing, controlling, and contending with outbreaks.
Methods: A retrospective exploratory case study approach was used. Data were collected over a 4-month period in 2012. The incidence rates of site-specific HAIs were analysed, and individual interviews were held with 23 bedside nurses and five nurse managers.
Findings: Five themes emerged from the interviews: comparison of healthcare-associated infections outbreaks; the nature of nurses’ work; impact of outbreaks on patient care; innovation and quality control in clinical practice; and increased and expanded IPAC measures. The incidence rates of methicillin-resistant Staphylococcus aureus, Clostridium difficile and vancomycin-resistant enterococci at the study site decreased, but remained above provincial benchmarks. Nurses experienced workload challenges, time pressures and psychological effects stemming from outbreaks and developed various innovations in response. Patient care was also affected.
Conclusion: Nurses’ work has been impacted by healthcare-associated infectious disease outbreaks. Nursing workloads should be quantified to facilitate the development of guidelines for optimum nurse–patient ratio during outbreaks.
Implications for Nursing and/or Health Policy: A strong evidence-based policy framework is required to address healthcare-associated infectious disease outbreaks. Infection prevention and control guidelines and procedures should be established provincially and nationally. An interdisciplinary approach is essential for the creation of comprehensive and innovative strategies. Nursing research has increased understanding of the implications of infectious diseases in hospitals. Building on the literature, findings from this study can be used to influence policies on the care of patients who have secondary infections. Nurse-driven protocols are important and can lead to the creation of best practice guidelines that can be implemented across settings
The Composition of Human Milk and Infant Faecal Microbiota Over the First Three Months of Life: A Pilot Study
peer-reviewedHuman milk contains a diverse array of bioactives and is also a source of bacteria for the developing infant gut. The aim of this study was to characterize the bacterial communities in human milk and infant faeces over the first 3 months of life, in 10 mother-infant pairs. The presence of viable Bifidobacterium and Lactobacillus in human milk was also evaluated. MiSeq sequencing revealed a large diversity of the human milk microbiota, identifying over 207 bacterial genera in milk samples. The phyla Proteobacteria and Firmicutes and the genera Pseudomonas, Staphylococcus and Streptococcus were the predominant bacterial groups. A core of 12 genera represented 81% of the microbiota relative abundance in milk samples at week 1, 3 and 6, decreasing to 73% at week 12. Genera shared between infant faeces and human milk samples accounted for 70–88% of the total relative abundance in infant faecal samples, supporting the hypothesis of vertical transfer of bacteria from milk to the infant gut. In addition, identical strains of Bifidobacterium breve and Lactobacillus plantarum were isolated from the milk and faeces of one mother-infant pair. Vertical transfer of bacteria via breastfeeding may contribute to the initial establishment of the microbiota in the developing infant intestine
The First Galaxies: Chemical Enrichment, Mixing, and Star Formation
Using three-dimensional cosmological simulations, we study the assembly
process of one of the first galaxies, with a total mass of 10^8 M_sun,
collapsing at z = 10. Our main goal is to trace the transport of the heavy
chemical elements produced and dispersed by a pair-instability supernova
exploding in one of the minihalo progenitors. To this extent, we incorporate an
efficient algorithm into our smoothed particle hydrodynamics code which
approximately models turbulent mixing as a diffusion process. We study this
mixing with and without the radiative feedback from Population III stars that
subsequently form in neighboring minihalos. Our simulations allow us to
constrain the initial conditions for second-generation star formation, within
the first galaxy itself, and inside of minihalos that virialize after the
supernova explosion. We find that most minihalos remain unscathed by ionizing
radiation or the supernova remnant, while some are substantially photoheated
and enriched to supercritical levels, likely resulting in the formation of
low-mass Population III or even Population II stars. At the center of the newly
formed galaxy, 10^5 M_sun of cold, dense gas uniformly enriched to 10^-3 Z_sun
are in a state of collapse, suggesting that a cluster of Population II stars
will form. The first galaxies, as may be detected by the James Webb Space
Telescope, would therefore already contain stellar populations familiar from
lower redshifts.Comment: 13 pages, 9 figures, published in Ap
Genetic counseling and testing practices for late-onset neurodegenerative disease: a systematic review
ObjectiveTo understand contemporary genetic counseling and testing practices for late-onset neurodegenerative diseases (LONDs), and identify whether practices address the internationally accepted goals of genetic counseling: interpretation, counseling, education, and support.MethodsFour databases were systematically searched for articles published from 2009 to 2020. Peer-reviewed research articles in English that reported research and clinical genetic counseling and testing practices for LONDs were included. A narrative synthesis was conducted to describe different practices and map genetic counseling activities to the goals. Risk of bias was assessed using the Qualsyst tool. The protocol was registered with PROSPERO (CRD42019121421).ResultsSixty-one studies from 68 papers were included. Most papers focused on predictive testing (58/68) and Huntington's disease (41/68). There was variation between papers in study design, study population, outcomes, interventions, and settings. Although there were commonalities, novel and inconsistent genetic counseling practices were identified. Eighteen papers addressed all four goals of genetic counseling.ConclusionContemporary genetic counseling and testing practices for LONDs are varied and informed by regional differences and the presence of different health providers. A flexible, multidisciplinary, client- and family-centered care continues to emerge. As genetic testing becomes a routine part of care for patients (and their relatives), health providers must balance their limited time and resources with ensuring clients are safely and effectively counseled, and all four genetic counseling goals are addressed. Areas of further research include diagnostic and reproductive genetic counseling/testing practices, evaluations of novel approaches to care, and the role and use of different health providers in practice
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