854 resultados para Collective dwelling
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In 1620, over the course of 66 days, 102 passengers called the Mayflower their home before arriving and settling in Plymouth, New England. In the years following the Louisiana Purchase of 1803 nearly 7 million people traversed extreme wilderness in covered wagons to found and settle the American West. This year, 2015, the first spaceport has opened in anticipation of sub orbital space flights in 2017 and manned settlement flights to mars by 2026. This thesis explores the questions: In this next phase of human exploration and settlement, what does it mean to dwell beyond earth? What are the current architectural limitations regarding structure and material sustainability? And, How can architecture elevate the traditionally sterile environments of survival shelters to that of permanent dwellings?
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The effects of individual teacher expectations have been the subject of intensive research. Results indicate that teachers use their expectations to adapt their interactions with their students to some degree (as summarized in a review by Jussim & Harber, 2005). This can in turn lead to expectancy-confirming student developments. While there are studies on the Pygmalion effect on individual students, there is only little research on teacher judgements of whole classes and schools. Our study aims to extend the perspective of teacher judgements at the collective level to stereotypes within the context of school tracking. The content and structure of teachers’ school track stereotypes are investigated as well as the question of whether these stereotypical judgements are related to teachers’ perception of obstacles to their teaching and their teaching self-efficacy beliefs. Cross-sectional data on 341 teachers at two different school types from the Panel Study at the Research School „Education and Capabilities“ in North Rhine-Westphalia (PARS) (see Bos et al., 2016) were used for two purposes: First, the structure of teachers’ stereotypes was identified via an exploratory factor analysis. Second, in follow-up regression analyses, the stereotype dimensions extracted were used to predict teachers’ perceptions of obstacles to their classroom work and their individual and collective teacher self-efficacy beliefs. Results showed that – after controlling for the average cognitive abilities and the average cultural capital of the students – teacher stereotypes were indeed related to perceived obstacles concerning their classroom work and their self-efficacy beliefs. After a discussion of the strengths and limitations of the present research, the article closes with a short proposal of a future research framework for collective Pygmalion effects. (DIPF/Orig.)
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Objective: To assess potentially inappropriate prescribing (PIP) using Beers (2012 version) and STOPP (2008 version) criteria in polypharmacy, community-dwelling, older patients. Methods: From the information collected in the invoicing data of the prescriptions and the electronic medical records, a sample was selected of 223 ≥ 65-year-old patients who were taking simultaneously 10 or more drugs per day. Beers and STOPP criteria were separately applied, and the results obtained with the two methods were compared. Results: A total of 141 (63.2%) patients presented at least one Beers criterion. The two most frequently observed Beers criteria independent of diagnosis were the use of benzodiazepines and the use of non-COX-2-selective non-steroidal anti-inflammatory drugs. With regard to Beers criteria considering diagnosis, the most frequent were the use of anticholinergic drugs in patients with lower urinary tract symptoms or benign prostatic hyperplasia, and the use of benzodiazepines, antipsychotics, Zolpidem or H2-antihistamines, in patients with dementia or cognitive impairment. A total of 165 (73.9%) patients had at least one PIP according to the STOPP criteria. Duplicate drug classes and long-term use of long-acting benzodiazepines were the two most frequent STOPP criteria. Discussion: Our study identified a high frequency of PIP in poly-medicated community-dwelling older patients. Simultaneous application of Beers and STOPP criteria represents a useful tool to improve prescribing in this population group.
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We apply the collective consumption model of Browning, Chiappori and Lewbel (2006) to analyse economic well-being and poverty among the elderly. The model focuses on individual preferences, a consumption technology that captures the economies of scale of living in a couple, and a sharing rule that governs the intra-household allocation of resources. The model is applied to a time series of Dutch consumption expenditure surveys. Our empirical results indicate substantial economies of scale and a wifeís share that is increasing in total expenditures. We further calculated poverty rates by means of the collective consumption model. Collective poverty rates of widows and widowers turn out to be slightly lower than traditional ones based on a standard equivalence scale. Poverty among women (men) in elderly couples, however, seems to be heavily underestimated (overestimated) by the traditional approach. Finally, we analysed the impact of becoming a widow(er). Based on cross-sectional evidence, we find that the drop (increase) in material well-being following the husbandís death is substantial for women in high (low) expenditure couples. For men, the picture is reversed.
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We provide a nonparametric 'revealed preference’ characterization of rational household behavior in terms of the collective consumption model, while accounting for general (possibly non-convex) individual preferences. We establish a Collective Axiom of Revealed Preference (CARP), which provides a necessary and sufficient condition for data consistency with collective rationality. Our main result takes the form of a ‘collective’ version of the Afriat Theorem for rational behavior in terms of the unitary model. This theorem has some interesting implications. With only a finite set of observations, the nature of consumption externalities (positive or negative) in the intra-household allocation process is non-testable. The same non-testability conclusion holds for privateness (with or without externalities) or publicness of consumption. By contrast, concavity of individual utility functions (representing convex preferences) turns out to be testable. In addition, monotonicity is testable for the model that assumes all household consumption is public.
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This thesis aims to understand how cells coordinate their motion during collective migration. As previously shown, the motion of individually migrating cells is governed by wave-like cell shape dynamics. The mechanisms that regulate these dynamic behaviors in response to extracellular environment remain largely unclear. I applied shape dynamics analysis to Dictyostelium cells migrating in pairs and in multicellular streams and found that wave-like membrane protrusions are highly coupled between touching cells. I further characterized cell motion by using principle component analysis (PCA) to decompose complex cell shape changes into a serial shape change modes, from which I found that streaming cells exhibit localized anterior protrusion, termed front narrowing, to facilitate cell-cell coupling. I next explored cytoskeleton-based mechanisms of cell-cell coupling by measuring the dynamics of actin polymerization. Actin polymerization waves observed in individual cells were significantly suppressed in multicellular streams. Streaming cells exclusively produced F-actin at cell-cell contact regions, especially at cell fronts. I demonstrated that such restricted actin polymerization is associated with cell-cell coupling, as reducing actin polymerization with Latrunculin A leads to the assembly of F-actin at the side of streams, the decrease of front narrowing, and the decoupling of protrusion waves. My studies also suggest that collective migration is guided by cell-surface interactions. I examined the aggregation of Dictyostelim cells under distinct conditions and found that both chemical compositions of surfaces and surface-adhesion defects in cells result in altered collective migration patterns. I also investigated the shape dynamics of cells suspended on PEG-coated surfaces, which showed that coupling of protrusion waves disappears on touching suspended cells. These observations indicate that collective migration requires a balance between cell-cell and cell-surface adhesions. I hypothesized such a balance is reached via the regulation of cytoskeleton. Indeed, I found cells actively regulate cytoskeleton to retain optimal cell-surface adhesions on varying surfaces, and cells lacking the link between actin and surfaces (talin A) could not retain the optimal adhesions. On the other hand, suspended cells exhibited enhanced actin filament assembly on the periphery of cell groups instead of in cell-cell contact regions, which facilitates their aggregation in a clumping fashion.
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This dissertation focuses on gaining understanding of cell migration and collective behavior through a combination of experiment, analysis, and modeling techniques. Cell migration is a ubiquitous process that plays an important role during embryonic development and wound healing as well as in diseases like cancer, which is a particular focus of this work. As cancer cells become increasingly malignant, they acquire the ability to migrate away from the primary tumor and spread throughout the body to form metastatic tumors. During this process, changes in gene expression and the surrounding tumor environment can lead to changes in cell migration characteristics. In this thesis, I analyze how cells are guided by the texture of their environment and how cells cooperate with their neighbors to move collectively. The emergent properties of collectively moving groups are a particular focus of this work as collective cell dynamics are known to change in diseases such as cancer. The internal machinery for cell migration involves polymerization of the actin cytoskeleton to create protrusions that---in coordination with retraction of the rear of the cell---lead to cell motion. This actin machinery has been previously shown to respond to the topography of the surrounding surface, leading to guided migration of amoeboid cells. Here we show that epithelial cells on nanoscale ridge structures also show changes in the morphology of their cytoskeletons; actin is found to align with the ridge structures. The migration of the cells is also guided preferentially along the ridge length. These ridge structures are on length scales similar to those found in tumor microenvironments and as such provide a system for studying the response of the cells' internal migration machinery to physiologically relevant topographical cues. In addition to sensing surface topography, individual cells can also be influenced by the pushing and pulling of neighboring cells. The emergent properties of collectively migrating cells show interesting dynamics and are relevant for cancer progression, but have been less studied than the motion of individual cells. We use Particle Image Velocimetry (PIV) to extract the motion of a collectively migrating cell sheet from time lapse images. The resulting flow fields allow us to analyze collective behavior over multiple length and time scales. To analyze the connection between individual cell properties and collective migration behavior, we compare experimental flow fields with the migration of simulated cell groups. Our collective migration metrics allow for a quantitative comparison between experimental and simulated results. This comparison shows that tissue-scale decreases in collective behavior can result from changes in individual cell activity without the need to postulate the existence of subpopulations of leader cells or global gradients. In addition to tissue-scale trends in collective behavior, the migration of cell groups includes localized dynamic features such as cell rearrangements. An individual cell may smoothly follow the motion of its neighbors (affine motion) or move in a more individualistic manner (non-affine motion). By decomposing individual motion into both affine and non-affine components, we measure cell rearrangements within a collective sheet. Finally, finite-time Lyapunov exponent (FTLE) values capture the stretching of the flow field and reflect its chaotic character. Applying collective migration analysis techniques to experimental data on both malignant and non-malignant human breast epithelial cells reveals differences in collective behavior that are not found from analyzing migration speeds alone. Non-malignant cells show increased cooperative motion on long time scales whereas malignant cells remain uncooperative as time progresses. Combining multiple analysis techniques also shows that these two cell types differ in their response to a perturbation of cell-cell adhesion through the molecule E-cadherin. Non-malignant MCF10A cells use E-cadherin for short time coordination of collective motion, yet even with decreased E-cadherin expression, the cells remain coordinated over long time scales. In contrast, the migration behavior of malignant and invasive MCF10CA1a cells, which already shows decreased collective dynamics on both time scales, is insensitive to the change in E-cadherin expression.
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Versión en inglés de la lección 3ª y materiales complementarios (diapositivas Pwp y cuestionario) correspondientes a la asignatura Derecho del Trabajo I (grupo ARA) del Grado en Derecho.
Resumo:
This dissertation focuses on gaining understanding of cell migration and collective behavior through a combination of experiment, analysis, and modeling techniques. Cell migration is a ubiquitous process that plays an important role during embryonic development and wound healing as well as in diseases like cancer, which is a particular focus of this work. As cancer cells become increasingly malignant, they acquire the ability to migrate away from the primary tumor and spread throughout the body to form metastatic tumors. During this process, changes in gene expression and the surrounding tumor environment can lead to changes in cell migration characteristics. In this thesis, I analyze how cells are guided by the texture of their environment and how cells cooperate with their neighbors to move collectively. The emergent properties of collectively moving groups are a particular focus of this work as collective cell dynamics are known to change in diseases such as cancer. The internal machinery for cell migration involves polymerization of the actin cytoskeleton to create protrusions that---in coordination with retraction of the rear of the cell---lead to cell motion. This actin machinery has been previously shown to respond to the topography of the surrounding surface, leading to guided migration of amoeboid cells. Here we show that epithelial cells on nanoscale ridge structures also show changes in the morphology of their cytoskeletons; actin is found to align with the ridge structures. The migration of the cells is also guided preferentially along the ridge length. These ridge structures are on length scales similar to those found in tumor microenvironments and as such provide a system for studying the response of the cells' internal migration machinery to physiologically relevant topographical cues. In addition to sensing surface topography, individual cells can also be influenced by the pushing and pulling of neighboring cells. The emergent properties of collectively migrating cells show interesting dynamics and are relevant for cancer progression, but have been less studied than the motion of individual cells. We use Particle Image Velocimetry (PIV) to extract the motion of a collectively migrating cell sheet from time lapse images. The resulting flow fields allow us to analyze collective behavior over multiple length and time scales. To analyze the connection between individual cell properties and collective migration behavior, we compare experimental flow fields with the migration of simulated cell groups. Our collective migration metrics allow for a quantitative comparison between experimental and simulated results. This comparison shows that tissue-scale decreases in collective behavior can result from changes in individual cell activity without the need to postulate the existence of subpopulations of leader cells or global gradients. In addition to tissue-scale trends in collective behavior, the migration of cell groups includes localized dynamic features such as cell rearrangements. An individual cell may smoothly follow the motion of its neighbors (affine motion) or move in a more individualistic manner (non-affine motion). By decomposing individual motion into both affine and non-affine components, we measure cell rearrangements within a collective sheet. Finally, finite-time Lyapunov exponent (FTLE) values capture the stretching of the flow field and reflect its chaotic character. Applying collective migration analysis techniques to experimental data on both malignant and non-malignant human breast epithelial cells reveals differences in collective behavior that are not found from analyzing migration speeds alone. Non-malignant cells show increased cooperative motion on long time scales whereas malignant cells remain uncooperative as time progresses. Combining multiple analysis techniques also shows that these two cell types differ in their response to a perturbation of cell-cell adhesion through the molecule E-cadherin. Non-malignant MCF10A cells use E-cadherin for short time coordination of collective motion, yet even with decreased E-cadherin expression, the cells remain coordinated over long time scales. In contrast, the migration behavior of malignant and invasive MCF10CA1a cells, which already shows decreased collective dynamics on both time scales, is insensitive to the change in E-cadherin expression.
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Due to their unpredictable behavior, stock markets are examples of complex systems. Yet, the dominant analysis of these markets as- sumes simple stochastic variations, eventually tainted by short-lived memory. This paper proposes an alternative strategy, based on a stochastic geometry defining a robust index of the structural dynamics of the markets and based on notions of topology defining a new coef- ficient that identifies the structural changes occurring on the S&P500 set of stocks. The results demonstrate the consistency of the random hypothesis as applied to normal periods but they also show its in- adequacy as to the analysis of periods of turbulence, for which the emergence of collective behavior of sectoral clusters of firms is mea- sured. This behavior is identified as a meta-routine.
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Free-riding behaviors exist in tourism and they should be analyzed from a comprehensive perspective; while the literature has mainly focused on free riders operating in a destination, the destinations themselves might also free ride when they are under the umbrella of a collective brand. The objective of this article is to detect potential free-riding destinations by estimating the contribution of the different individual destinations to their collective brands, from the point of view of consumer perception. We argue that these individual contributions can be better understood by reflecting the various stages that tourists follow to reach their final decision. A hierarchical choice process is proposed in which the following choices are nested (not independent): “whether to buy,” “what collective brand to buy,” and “what individual brand to buy.” A Mixed Logit model confirms this sequence, which permits estimation of individual contributions and detection of free riders.
Food consumption and risk of malnutrition in community-dwelling very old Spanish adults (≥ 80 years)
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Introduction: There are few studies assessing overall diet and food patterns of the oldest population. Objectives: To examine food groups consumption (grams and servings) and their compliance with the dietary guidelines in community-dwelling very old Spanish adults. The relationship with the risk of malnutrition was also studied. Methods: Within the cross-sectional health study of elderly people of Villanueva de la Cañada (Madrid, Spain), in 98 non-institutionalized elders aged ≥ 80 years (66% women) food consumption was calculated from a 24-hour dietary recall and nutritional risk was assessed by Mini Nutritional Assessment (MNA). Statistical significance was evaluated at 95% confidence level (p < 0.05). Results: Men consumed significantly higher amounts of snacks/pickles and alcoholic beverages. The consumption of cereals/grain products (2 servings/day), vegetables (1.5 servings/day) and meat, fish, eggs (1.4 servings/day), was below desirable levels. As nutritional status got worse, fruit consumption was significantly smaller (p = 0.039). Relatively weak but highly significant correlations were found between MNA and oils/fats, fruits and alcoholic beverages. After adjustment for energy intake, oils and fats and fruits associations disappeared whereas a negative association between milk/dairy products and MNA was found. Conclusions: Dietary patterns of the elderly population of Villanueva are departing from the traditional Mediterranean diet and though adequate consumption of fruits, milk/dairy products, oils/fats and sugar/confectionery has been achieved, cereals/grain products, vegetables and the meat,fish,eggs group consumption was below the desirable levels. Deterioration of the nutritional status coincided with a reduction in the consumption of all food groups except for ready meals and milk/dairy products whose consumption increased. Further research on the influence of fruit, milk/dairy products, wine and olive oil consumption on nutritional status is required.
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This dissertation presents a thick ethnography that engages in the micro-analysis of the situationality of black middle-class collective identification processes through an examination of performances by members of the nine historically black sororities and fraternities at Atlanta Greek Picnic, an annual festival that occurs at the beginning of June in Atlanta, Georgia. It mainly attracts undergraduate and graduate members of these university-based organizations, as they exist all over the United States. This exploration of black Greek-letter organization (BGLO) performances uncovers processes through which young black middle-class individuals attempt to combine two universes that are at first glance in complete opposition to each other: the domain of the traditional black middle-class values with representations and fashions stemming from black popular culture. These constructions also attempt to incorporate—in a contradiction of sorts— black popular cultural elements in the objective to deconstruct the social conservatism that characterizes middle-class values, particularly in relation to sexuality and its representation in social behaviors and performances. This negotiation between prescribed v middle-class values of respectability and black popular culture provides a space wherein black individuals challenge and/or perpetuate those dominant tropes through identity performances that feed into the formation of black sexual politics, which I examine through a variety of BGLO staged and non-staged performances. ^
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info:eu-repo/semantics/publishedVersion