2,891 research outputs found
Sequent Occupance in the Santa Clara Valley, California
The Santa Clara Valley beautifully exemplifies sequent occupance. Here an amazing drama has unfolded from the time of the primitive Amerindian, then through the Spanish and Mexican Period, the days of the cattle barons, the wheat bonanzas, the specialized agriculture at the turn of the century, and finally the period of immigration, urbanization, and industrialization (primarily electronic-missile defense). In his study published in 1932, Jan O. M. Broek dealt with the valley from the time of the Amerindian to the highly specialized horticulture of the 1920s. The present study purposes to telescope the work of Broek and to show that the Santa Clara Valley of his study is today but a nostalgic memory. The march of industry, the burgeoning population, and the ever-quickening pace of today, have virtually obliterated the landscape Broek described just thirty-three years ago
Letter from Langdon C. Easton to George Sibley, February 3, 1847
Transcript of Letter from Langdon C. Easton to brother-in-law, George Sibley, February 3, 1847. Easton discusses the Mexican-American War
A clinical audit of the nutritional status and need for nutrition support amongst head and neck cancer patients treated with radiotherapy
Radiotherapy is an effective treatment for head and neck cancers but patients often experience side effects which lead to weight loss. Nutrition intervention in the form of counselling or oral nutrition support (ONS) is frequently needed for these patients. For some patients, tube feeding is required to minimise weight loss during treatment.MethodData was collected on 48 patients who received radiotherapy to the head and neck region over a nine-month period (June 2009âMarch 2010). Retrospective data collection was commenced in July 2010. Each patientâs Diet Therapy Department record was reviewed. Main outcome measures were: 1) type of nutrition support; 2) percentage weight change during treatment; and 3) Patient-Generated Subjective Global Assessment Global (PG-SGA) rating.ResultsOn initial assessment 28 (77.8%) patients were classified as well nourished using the PG-SGA. Mean weight loss during radiotherapy was 5.74%. Risk factors for the need for ONS and enteral nutrition support (ENS) were older age, presence of nutrition impact symptoms, high-risk tumour sites, advanced disease and chemotherapy. No significant difference was shown in weight loss between ONS and ENS groups.ConclusionThis study identified the need for early dietetic intervention for high nutritional risk groups of head and neck cancer patients to prevent significant weight loss. Pre-treatment nutritional status did not influence weight loss during treatment. ONS alone cannot prevent significant weight loss in patients with multiple nutrition impact symptoms. Early enteral feeding should be considered in this group of patients
How do ecological perspectives help understand schools as sites for teacher learning?
Schools are sites of teachersâ professional learning for both new entrants and experienced practitioners. In this paper, schools are conceptualised as complex, multidimensional ecologies that are constituted by the relations that exist between school leaders, teachers, mentors and all members of the school community. As relational environments, the conditions affecting professional learning â both formal and informal â are constantly dynamic, with multiple and simultaneous interactions taking place between these stakeholders. Interactions are also multi-layered â between the school system, individuals, classrooms, the community and the policy environment. School leaders are a major influence on these dynamics and affect how schools act as sites of professional formation, mediating external policy as well as affecting micro-dynamics within individual school systems. The challenge of realising professional learning within these relational contexts can be viewed as a âwicked problemâ, a feature of complex systems that resists simplified solutions. In conceptualising a complex ecology at work, we illuminate the relational dynamics with a focus, for all stakeholders within schools, including leaders, on the need to recognise and value the importance of âemergenceâ in professional learning. This means embracing inevitable uncertainty as a feature of schools as complex systems
Mechanical property evaluation of an Al-2024 alloy subjected to HPT processing
An aluminum-copper alloy (Al-2024) was successfully subjected to high-pressure torsion (HPT) up to five turns at room temperature under an applied pressure of 6.0 GPa. The Al-2024 alloy is used as a fuselage structural material in the aerospace sector. Mechanical properties of the HPT-processed Al-2024 alloy were evaluated using the automated ball indentation technique. This test is based on multiple cycles of loading and unloading where a spherical indenter is used. After two and five turns of HPT, the Al-2024 alloy exhibited a UTS value of ~1014 MPa and ~1160 MPa respectively, at the edge of the samples. The microhardness was measured from edges to centers for all HPT samples. These results clearly demonstrate that processing by HPT gives a very significant increase in tensile properties and the microhardness values increase symmetrically from the centers to the edges. Following HPT, TEM examination of the five-turn HPT sample revealed the formation of high-angle grain boundaries and a large dislocation density with a reduced average grain size of ~80 nm. These results also demonstrate that high-pressure torsion is a processing tool for developing nanostructures in the Al-2024 alloy with enhanced mechanical propertie
In Vitro Reconstitution of Skin: Fibroblasts Facilitate Keratinocyte Growth and Differentiation on Acellular Reticular Dermis
Extensive full-thickness burns require replacement of both epidemis and dermis. We have described a method in which allogeneic dermis from engrafted cryopreserved cadaver skin was combined with cultured autologous keratinocytes. In the present study we combined human keratinocytes and fibroblasts, and acellular human dermis in vitro and transplanted this âreconstituted skinâ into athymic mice. Both human papillary dermis in which the basement membrane zone has been retained and human reticular dermis that has been repopulated with human dermal fibroblasts are good substrates for keratinocyte attachment, stratification, growth, and differentiation. Both of these dermal preparations can be lyophilized and stored at room temperature without losing their ability to support keratinocyte growth. In contrast, human papillary dermis that has been treated with trypsin lacks laminin and collagen type IV in the BMZ and supports keratinocyte attachment and differentiation less well
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A Galerkin boundary element method for high frequency scattering by convex polygons
In this paper we consider the problem of time-harmonic acoustic scattering in two dimensions by convex polygons. Standard boundary or finite element methods for acoustic scattering problems have a computational cost that grows at least linearly as a function of the frequency of the incident wave. Here we present a novel Galerkin boundary element method, which uses an approximation space consisting of the products of plane waves with piecewise polynomials supported on a graded mesh, with smaller elements closer to the corners of the polygon. We prove that the best approximation from the approximation space requires a number of degrees of freedom to achieve a prescribed level of accuracy that grows only logarithmically as a function of the frequency. Numerical results demonstrate the same logarithmic dependence on the frequency for the Galerkin method solution. Our boundary element method is a discretization of a well-known second kind combined-layer-potential integral equation. We provide a proof that this equation and its adjoint are well-posed and equivalent to the boundary value problem in a Sobolev space setting for general Lipschitz domains
The case for internalising externalities in a sustainable rail asset base
Although the concept of sustainability and Sustainable development has tended to be mostly associated with the management of natural resources and the consequent environmental impact, the most accepted definition draws together its social, economic and environmental dimensions. The rail industry, as provider of a low carbon transport system, is well placed to have a significant role to play in promoting an environmental, economic and social balance that can be sustained and afforded for the foreseeable future.
The paper suggests that a more comprehensive perspective on the scope of a sustainable intervention in rail infrastructure assets is needed, arguing that the necessary whole life evaluation process should include an additional positive externality: the uplift in knowledge, skill and expertise that comes about as a result of participation in projects and programmes. The inclusion of this benefit would provide a more accurate representation of value to support investment decision making and strengthen the case for a broader funding base. And that the demonstration of the correlation between participation in projects and programmes and the consequent uplift in skill, knowledge and expertise could be used to shift the emphasis in rail project planning
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