151 research outputs found
Coupled non-equilibrium growth equations: Self-consistent mode coupling using vertex renormalization
We find that studying the simplest of the coupled non-equilibrium growth
equations of Barabasi by self-consistent mode coupling requires the use of
dressed vertices. Using the vertex renormalization, we find a roughness
exponent which already in the leading order is quite close to the numerical
value.Comment: 7 pages, 3 figure
Heavy Metal Contamination of Soils and Vegetation around Solid Waste Dumps in Port Harcourt, Nigeria
Assessment of the levels of copper, zinc and lead in soils and
vegetation around solid waste dumpsites in Port Harcourt and environs
were carried out in 2005 using Atomic Absorption spectrophotometric
technique. Physical parameters such as pH and particle size were also
determined. The results show that the mean concentrations of copper in
transect and profile soils and vegetation were 1.20 \ub1 0.83ppm,
2.57 \ub1 1.87ppm, 1.48 \ub1 1.61ppm respectively at the East
\u2013 West road dumpsite and 2.42 \ub1 1.87ppm, 1.40 \ub1
0.61ppm, 1.39 \ub1 0.67ppm respectively at the Kaduna/Afam street
dumpsite. The mean concentrations of zinc in soil and vegetations along
the transect were 12.83 \ub1 4.65ppm, 2.68 \ub1 1.82ppm, 1.33
\ub1 0.64ppm, 0.80 \ub1 0.60ppm respectively at the Kaduna/Afam
street dumpsite. The mean concentrations of lead in soils and
vegetation were 0.26 \ub1 0.21ppm, 0.28 \ub1 0.24ppm, 1.48 \ub1
0.12ppm respectively at the East \u2013 West road dumpsite and 0.45
\ub1 0.37ppm, 0.20 \ub1 0.08ppm, 0.39 \ub1 0.17ppm respectively
at the Kaduna/Afam street dumpsite. The order of occurrence of the
heavy metals in the topsoils of the study areas was Zn > Cu > Pb.
The levels of copper and zinc in soils from the waste dumpsite were
significantly different (P <0.05) from soil sample elsewhere. The
differences in the levels of copper, zinc and lead in soils and
vegetations as well as dumpsite and outside dumpsite were not
significant (P <0.05). The results indicate that solid wastes
contributed to the levels of heavy metals in soils and vegetation. Also
the concentrations of the metals in soils do not depend on the age of
the waste dump rather, on the source, composition and the topography of
the dumpsite. @ JASE
Nitrogen Mineralization in Selected Solid Waste Dumpsites in Port Harcourt, Nigeria.
Organic wastes in selected waste dumpsites in Port Harcourt were
successively incubated with sandy-loam soils for days at 27\ub0C,
under aerobic conditions. The results showed marked decrease in total
nitrogen in the organic wastes which was observed as loss of nitrogen.
The process of nitrification and incorporation of (NH4)2SO4 affected
the pH which ranged from 5.9 to 7.9. The cumulative mineral nitrogen
released increased with incubation periods and the rate of organic
application up to 28th day, with a maximum release of 456.40ppm at a
rate of 61MT/ha organic application. The release of mineral N decreased
on the 56th day with a minimum of 177.80ppm at a rate of 60MT/ha of
organic fertilizer only. An enriched organic. Waste soil and organic
waste treated soil had a boosting effect on the release of mineral
nitrogen. The amount of mineral nitrogen released was higher for
(NH4)2SO4 fertilizer treated soil than for organic waste treated soil.
The mineralization rate was found to decrease with increasing age of
the waste dumps. It was therefore recommended that organic wastes
should be sorted and composted for use as organic fertilizers to
augment inorganic fertilizer
The Capaciousness of No: Affective Refusals as Literacy Practices
© 2020 The Authors. Reading Research Quarterly published by Wiley Periodicals, Inc. on behalf of International Literacy Association The authors considered the capacious feeling that emerges from saying no to literacy practices, and the affective potential of saying no as a literacy practice. The authors highlight the affective possibilities of saying no to normative understandings of literacy, thinking with a series of vignettes in which children, young people, and teachers refused literacy practices in different ways. The authors use the term capacious to signal possibilities that are as yet unthought: a sense of broadening and opening out through enacting no. The authors examined how attention to affect ruptures humanist logics that inform normative approaches to literacy. Through attention to nonconscious, noncognitive, and transindividual bodily forces and capacities, affect deprivileges the human as the sole agent in an interaction, thus disrupting measurements of who counts as a literate subject and what counts as a literacy event. No is an affective moment. It can signal a pushback, an absence, or a silence. As a theoretical and methodological way of thinking/feeling with literacy, affect proposes problems rather than solutions, countering solution-focused research in which the resistance is to be overcome, co-opted, or solved. Affect operates as a crack or a chink, a tiny ripple, a barely perceivable gesture, that can persist and, in doing so, hold open the possibility for alternative futures
Quantum critical point and scaling in a layered array of ultrasmall Josephson junctions
We have studied a quantum Hamiltonian that models an array of ultrasmall
Josephson junctions with short range Josephson couplings, , and charging
energies, , due to the small capacitance of the junctions. We derive a new
effective quantum spherical model for the array Hamiltonian. As an application
we start by approximating the capacitance matrix by its self-capacitive limit
and in the presence of an external uniform background of charges, . In
this limit we obtain the zero-temperature superconductor-insulator phase
diagram, , that improves upon previous theoretical
results that used a mean field theory approximation. Next we obtain a
closed-form expression for the conductivity of a square array, and derive a
universal scaling relation valid about the zero--temperature quantum critical
point. In the latter regime the energy scale is determined by temperature and
we establish universal scaling forms for the frequency dependence of the
conductivity.Comment: 18 pages, four Postscript figures, REVTEX style, Physical Review B
1999. We have added one important reference to this version of the pape
Transfer Matrices and Partition-Function Zeros for Antiferromagnetic Potts Models. V. Further Results for the Square-Lattice Chromatic Polynomial
We derive some new structural results for the transfer matrix of
square-lattice Potts models with free and cylindrical boundary conditions. In
particular, we obtain explicit closed-form expressions for the dominant (at
large |q|) diagonal entry in the transfer matrix, for arbitrary widths m, as
the solution of a special one-dimensional polymer model. We also obtain the
large-q expansion of the bulk and surface (resp. corner) free energies for the
zero-temperature antiferromagnet (= chromatic polynomial) through order q^{-47}
(resp. q^{-46}). Finally, we compute chromatic roots for strips of widths 9 <=
m <= 12 with free boundary conditions and locate roughly the limiting curves.Comment: 111 pages (LaTeX2e). Includes tex file, three sty files, and 19
Postscript figures. Also included are Mathematica files data_CYL.m and
data_FREE.m. Many changes from version 1: new material on series expansions
and their analysis, and several proofs of previously conjectured results.
Final version to be published in J. Stat. Phy
A Unified Algebraic Approach to Few and Many-Body Correlated Systems
The present article is an extended version of the paper {\it Phys. Rev.} {\bf
B 59}, R2490 (1999), where, we have established the equivalence of the
Calogero-Sutherland model to decoupled oscillators. Here, we first employ the
same approach for finding the eigenstates of a large class of Hamiltonians,
dealing with correlated systems. A number of few and many-body interacting
models are studied and the relationship between their respective Hilbert
spaces, with that of oscillators, is found. This connection is then used to
obtain the spectrum generating algebras for these systems and make an algebraic
statement about correlated systems. The procedure to generate new solvable
interacting models is outlined. We then point out the inadequacies of the
present technique and make use of a novel method for solving linear
differential equations to diagonalize the Sutherland model and establish a
precise connection between this correlated system's wave functions, with those
of the free particles on a circle. In the process, we obtain a new expression
for the Jack polynomials. In two dimensions, we analyze the Hamiltonian having
Laughlin wave function as the ground-state and point out the natural emergence
of the underlying linear symmetry in this approach.Comment: 18 pages, Revtex format, To appear in Physical Review
Value co-creation through multiple shopping channels: the interconnections with social exclusion and wellbeing
This study examines consumers’ value co-creation via several shopping channels including a traditional out-of-home shopping channel and “smart” channels where consumers use a computer, a mobile phone or social media. It focuses on the effect that value co-creation has on consumers’ shopping behaviour as well as on the perceived contribution of a shopping channel to their wellbeing, with a focus on individuals who perceive themselves as being socially excluded, particularly by mobility disability. The project was carried out in the USA using an online survey (n=1220). Social exclusion has a positive statistically significant effect on respondents’ self-connection with all channels; for many socially excluded respondents the shopping channel has an important role in their lives. Self-connection with the channel has a positive effect on value co-creation and there is a positive relationship between value co-creation and the perceived contribution of the channel on wellbeing. When consumers help other individuals in their decision making they not only create value for the retailer and for other customers but also contribute positively to their own wellbeing. Importantly, for smart shopping channels where consumers use a computer or a mobile phone, the impact of value co-creation on the perceived contribution of these channels to consumer wellbeing are stronger for shoppers with a mobility disability than for those without such a disability
Digitizing a Face-to-Face Group Fatigue Management Program: Exploring the Views of People With Multiple Sclerosis and Health Care Professionals Via Consultation Groups and Interviews.
BACKGROUND: Fatigue is one of the most common and debilitating symptoms of multiple sclerosis (MS) and is the main reason why people with MS stop working early. The MS Society in the United Kingdom funded a randomized controlled trial of FACETS-a face-to-face group-based fatigue management program for people with multiple sclerosis (pwMS)-developed by members of the research team. Given the favorable trial results and to help with implementation, the MS Society supported the design and printing of the FACETS manual and materials and the national delivery of FACETS training courses (designed by the research team) for health care professionals (HCPs). By 2015 more than 1500 pwMS had received the FACETS program, but it is not available in all areas and a face-to-face format may not be suitable for, or appeal to, everyone. For these reasons, the MS Society funded a consultation to explore an alternative Web-based model of service delivery. OBJECTIVE: The aim of this study was to gather views about a Web-based model of service delivery from HCPs who had delivered FACETS and from pwMS who had attended FACETS. METHODS: Telephone consultations were undertaken with FACETS-trained HCPs who had experience of delivering FACETS (n=8). Three face-to-face consultation groups were held with pwMS who had attended the FACETS program: London (n=4), Liverpool (n=4), and Bristol (n=7). The interviews and consultation groups were digitally recorded and transcribed. A thematic analysis was undertaken to identify key themes. Toward the end of the study, a roundtable meeting was held to discuss outcomes from the consultation with representatives from the MS Society, HCPs, and pwMS. RESULTS: Key challenges and opportunities of designing and delivering an integrated Web-based version of FACETS and maintaining user engagement were identified across 7 themes (delivery, online delivery, design, group, engagement, interactivity, and HCP relationships). Particularly of interest were themes related to replicating the group dynamics and the lack of high-quality solutions that would support the FACETS' weekly homework tasks and symptom monitoring and management. CONCLUSIONS: A minimum viable Web-based version of FACETS was suggested as the best starting point for a phased implementation, enabling a solution that could then be added to over time. It was also proposed that a separate study should look to create a free stand-alone digital toolkit focusing on the homework elements of FACETS. This study has commenced with a first version of the toolkit in development involving pwMS throughout the design and build stages to ensure a user-centered solution
Risk Predictors and Symptom Features of Long COVID Within a Broad Primary Care Patient Population Including Both Tested and Untested Patients
Introduction: Symptoms may persist after the initial phases of COVID-19 infection, a phenomenon termed long COVID. Current knowledge on long COVID has been mostly derived from test-confirmed and hospitalized COVID-19 patients. Data are required on the burden and predictors of long COVID in a broader patient group, which includes both tested and untested COVID-19 patients in primary care.
Methods: This is an observational study using data from Platform C19, a quality improvement program-derived research database linking primary care electronic health record data (EHR) with patient-reported questionnaire information. Participating general practices invited consenting patients aged 18– 85 to complete an online questionnaire since 7th August 2020. COVID-19 self-diagnosis, clinician-diagnosis, testing, and the presence and duration of symptoms were assessed via the questionnaire. Patients were considered present with long COVID if they reported symptoms lasting ≥ 4 weeks. EHR and questionnaire data up till 22nd January 2021 were extracted for analysis. Multivariable regression analyses were conducted comparing demographics, clinical characteristics, and presence of symptoms between patients with long COVID and patients with shorter symptom duration.
Results: Long COVID was present in 310/3151 (9.8%) patients with self-diagnosed, clinician-diagnosed, or test-confirmed COVID-19. Only 106/310 (34.2%) long COVID patients had test-confirmed COVID-19. Risk predictors of long COVID were age ≥ 40 years (adjusted Odds Ratio [AdjOR]=1.49 [1.05– 2.17]), female sex (adjOR=1.37 [1.02– 1.85]), frailty (adjOR=2.39 [1.29– 4.27]), visit to A&E (adjOR=4.28 [2.31– 7.78]), and hospital admission for COVID-19 symptoms (adjOR=3.22 [1.77– 5.79]). Aches and pain (adjOR=1.70 [1.21– 2.39]), appetite loss (adjOR=3.15 [1.78– 5.92]), confusion and disorientation (adjOR=2.17 [1.57– 2.99]), diarrhea (adjOR=1.4 [1.03– 1.89]), and persistent dry cough (adjOR=2.77 [1.94– 3.98]) were symptom features statistically more common in long COVID.
Conclusion: This study reports the factors and symptom features predicting long COVID in a broad primary care population, including both test-confirmed and the previously missed group of COVID-19 patients
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