13,364 research outputs found
Modelling the multiplier effect of a local food system
Received: February 1st, 2021 ; Accepted: May 10th, 2021 ; Published: May 13th, 2021 ; Correspondence: [email protected] of rural communities, benefits for local farmers and environment are
expected outcomes of local food initiatives which are emerging as an opposition to the adverse
social and economic effects of globalization. Local food networks diversify the rural economy,
promote greater economic independence and local potential, improve the area’s image and reduce
GHG emissions. The purchase of local food increases incomes of both the community and local
producers, as well as increases employment and related multiplier effects at the local level, for
example, increased value of new production, import substitution, increased incomes, and created
additional jobs. Revitalisation of rural communities, benefits for local farmers and environment
are expected outcomes of local food initiatives which are emerging as an opposition to the adverse
social and economic effects of globalization It has been revealed that much of current research
on local and regional food networks lacks a strong theoretical grounding and quantitative rigor;
however, community development practitioners and planners need objective and research-based
information for food system design and implementation in order to produce community or
regional wellbeing. The aim of the paper is to develop the concept of an integrated assessment
model of local food systems based on the analysis of the literature, which would provide a basis
for empirical analysis. The analysis model contains dimensions of sustainable development,
allowing us to assess not only direct effects (income, reduced greenhouse gas emissions etc.) but
also indirect ones (economic, social and environmental resilience of local communities)
Vortex and gap generation in gauge models of graphene
Effective quantum field theoretical continuum models for graphene are
investigated. The models include a complex scalar field and a vector gauge
field. Different gauge theories are considered and their gap patterns for the
scalar, vector, and fermion excitations are investigated. Different gauge
groups lead to different relations between the gaps, which can be used to
experimentally distinguish the gauge theories. In this class of models the
fermionic gap is a dynamic quantity. The finite-energy vortex solutions of the
gauge models have the flux of the "magnetic field" quantized, making the
Bohm-Aharonov effect active even when external electromagnetic fields are
absent. The flux comes proportional to the scalar field angular momentum
quantum number. The zero modes of the Dirac equation show that the gauge models
considered here are compatible with fractionalization
An Analysis of Learning Outcomes in a Freshman Seminar Learning Community that Utilizes Peer Mentoring at a Community College
While there has been research on the effects of utilizing Peer Mentors within Learning Communities with regards to retention data, little research has been done to show the effects that Peer Mentoring has on learning outcomes within a Learning Community. Using anecdotal evidence from peer mentors working within a Learning Community at an urban community college, we describe the effects that individual mentors have had on individual first-semester students. For a preliminary quantitative analysis, a pre post survey was given to two groups of Learning Community students, one group which had peer mentors attached to their Learning Communities (PMLC), and one which did not (non-PMLC). Using an independent t-test, we were able to show that there were some improvements in familiarity from pre to post in both groups and that, in some cases, the PMLC group showed greater improvement than the non-PMLC group, the results were not statistically significant
Performance of the Halex in Logitudinal Studies of Older Adults
Goal: The Halex is an indicator of health status that combines self-rated health and activity limitations, which has been used by NCHS to predict future years of healthy life. The scores for each health state were developed based on strong assumptions, notably that a person in excellent health with ADL disabilities is as healthy as a person in poor health with no disabilities. Our goal was to examine the performance of the Halex as a longitudinal measure of health for older adults, and to improve the scoring if necessary.
Methods: We used data from the Cardiovascular Health Study (CHS) to compare the relationship of baseline health to health 2 years later. Subject ages ranged from 65 to 103 (mean age 75). A total of 40,827 transitions were available for analysis. We examined whether Halex scores at time 0 were related monotonically to scores two years later, and iterated the original scores to improve the fit over time.
Findings: The original Halex scores were not consistent over time. Persons in excellent health with ADL limitations were much healthier 2 years later than people in poor health with no limitations, even though they had been assumed to have identical health. People with ADL limitations had higher scores than predicted. The assumptions made in creating the Halex were not upheld in the data.
Conclusions: The new iterated scores are specific to older adults, are appropriate for longitudinal data, and are relatively assumption-free. We recommend the use of these new scores for longitudinal studies of older adults that use the Halex health states
A mitotic kinase scaffold depleted in testicular seminomas impacts spindle orientation in germ line stem cells.
Correct orientation of the mitotic spindle in stem cells underlies organogenesis. Spindle abnormalities correlate with cancer progression in germ line-derived tumors. We discover a macromolecular complex between the scaffolding protein Gravin/AKAP12 and the mitotic kinases, Aurora A and Plk1, that is down regulated in human seminoma. Depletion of Gravin correlates with an increased mitotic index and disorganization of seminiferous tubules. Biochemical, super-resolution imaging, and enzymology approaches establish that this Gravin scaffold accumulates at the mother spindle pole during metaphase. Manipulating elements of the Gravin-Aurora A-Plk1 axis prompts mitotic delay and prevents appropriate assembly of astral microtubules to promote spindle misorientation. These pathological responses are conserved in seminiferous tubules from Gravin(-/-) mice where an overabundance of Oct3/4 positive germ line stem cells displays randomized orientation of mitotic spindles. Thus, we propose that Gravin-mediated recruitment of Aurora A and Plk1 to the mother (oldest) spindle pole contributes to the fidelity of symmetric cell division
Recommended from our members
Changing Scales: Greenways From Region To Place – The Case Of The Algarve, Portugal.
This article aims to reflect and debate around the operational value of the greenway concept, while paramount instrument for landscape planning and management, divided in two parts. The first one focuses on the definition and evolution of the greenway concept and its relations with other fundamental concepts, such as continuum naturale, ecological structure and green infrastructure. In this conceptual approach, the main scope is the importance of accurate criteria definition for greenway design, considering the transposition between different scales. In the latter part of the article, the case study of the Algarve, southern Portugal, is presented, where greenway design occurs at a regional scale, integrated in a system designated as Estrutura Regional de Protecção e Valorização Ambiental (ERPVA, Regional Environmental Protection and Valorization Structure), within the Plano Regional de Ordenamento do Território do Algarve (PROT-Algarve, Territorial Management Plan of the Algarve), setting guidelines for the transposition for the municipal level landscape management instruments. The goal is to assess the challenges, opportunities and constraints enclosed in the scale adaptation process, namely through the analysis of the revision processes of the Planos Directores Municipais (PDM, municipal master plans) of Lagoa and Silves
- …