Aristotle on Property Rights

The thesis is that a theory of private property rights can be reconstructed from the remarks about property scattered throughout Aristotle’s writings. His working concept is as follows: X has a property right in P if, and only if, X possesses P in such a way that the use of P is up to X and the alienation of P (giving P away or selling P) is up to X. It is argued that Aristotle provides clear answers to the important questions which should be answered by a theory of property rights: (1) What individuals can properly hold rights to property? (2) To what objects can they have property rights? (3) What form is taken by exercise of property rights? (4) What is the general moral justification for the thesis that individuals have property rights? (5) Under what circumstances do individuals justly acquire title to specific objects and under what circumstances do they come to possess them unjustly? (6) Under what circumstances, if any, may property rights be aIienabIe, defeasible, or quaIifiable? (7) What specific social policies are implied by property rights, i.e. in what way should property rights be protected and what constraints, if any, do individual property rights place upon the conduct of government? In his famous defense of private property against Plato’s communism, Aristotle emphasizes not only the harmful aggregate consequences of communism but also the moral importance of the individual. The Aristotelian justification for private property rights is grounded in his theory of justice, his conception of eudaimonia and moral virtue, and his thesis that man is a political animal. The Aristotelian theory of property rights must accordingly be clearly distinguished from the Lockean theory of natural property rights. For Aristotle property rights are grounded in the political rights of citizens, and they are consequently limited in certain respects. There are natural limits to just acquisition of property, property rights are subordinate to political duties, and the exercise of property rights is subject to the moral requirement that private property should be put to common use

Aristotle on Nature, Law and Justice

Aristotle is often represented as the father of natural law. Nevertheless, many modern commentators deny the concept of natural law or natural right a legitimate place in his philosophical thought. This denial generally rests on two sorts of arguments: that it is impossible to construct a natural law interpretation of Aristotle which is consistent with all of the texts, and that the natural law claims in particular are manifestly too inconsistent with well attested Aristotelian doctrines for it to be credible to attribute them to him

Space deployable domed solar concentrator with foldable panels and hinge therefor

A space deployable solar energy concentrator is formed of a dome-shaped arrangement of compactly stowable flat panel segments mounted on a collapsible, space-deployable support structure of interconnected linear components. The support structure is comprised of a plurality of tensioned, curvilinear edge strips which extend in a radial direction from a prescribed vertex of a surrounding umbrella-like framework of radially extending rib members. Between a respective pair of radially-extending, curvilinear edge strips an individual wedge-shaped panel section is formed of a plurality of multi-segment lens panel strips each of which is supported in tension between the pair of edge strips by a pair of circumferentially extending catenary cord members connected to a pair of ribs of the surrounding umbrella-like framework. A respective lens panel strip is comprised of a plurality of flat, generally rectangular-shaped, energy-directing panels arranged side-by-side in the circumferential direction of the dome. Adjacent panels are interconnected by flexible U-shaped hinges which overlap opposing edges of adjacent panels and engage respective cylindrically-shaped, load distribution bars that slide within the flexible hinges. Because each U-shaped hinge is flexible, it is permitted to shift in the circumferential direction of the panel section to facilitate stowage and deployment of the dome

Laboratory and theoretical studies of baroclinic processes

An understanding is being developed for processes which may be important in the atmosphere, and the definition and analysis of baroclinic experiments utilizing the geophysical fluid flow cells (GFFC) apparatus in microgravity space flights. Included are studies using numerical codes, theoretical models, and terrestrial laboratory experiments. The numerical modeling is performed in three stages: calculation of steady axisymmetric flow, calculation of fastest-growing linear eigenmodes, and nonlinear effects (first, wave-mean flow interactions, then wave-wave interactions). The code can accommodate cylindrical, spherical, or channel geometry. It uses finite differences in the vertical and meridional directions, and is spectral in the azimuthal. The theoretical work was mostly in the area of effects of topography upon the baroclinic instability problem. The laboratory experiments are performed in a cylindrical annulus which has a temperture gradient imposed upon the lower surface and an approximately isothermal outer wall, with the upper and inner surfaces being nominally thermally insulating

Methods for Predicting Mechanical Deformations in the Breast During Clinical Breast Biopsy

A new method for clinical breast biopsy is presented, based on a deformable finite element model of the breast. The geometry of the model is constructed from MR data, and its mechanical properties are based on a nonlinear material model. This method allows imaging the breast without compression before the procedure, then compressing the breast and using the finite element model to predict the tumor\u27s position

Methods for Modeling and Predicting Mechanical Deformations of the Breast During Interventional Procedures

When doing high field (1.5T) magnetic resonance breast imaging, the use of compression plate during imaging after a contrast-agent injection may critically change the enhancement characteristics of the tumor, making the tracking of its boundaries very difficult. A new method for clinical breast biopsy is presented based on a deformable finite element model of the breast. The geometry of the model is constructed from MR data, and its mechanical properties are based on a non-linear material model. This method allows imaging the breast without compression before the procedure, then compressing the breast and using the finite element model to predict the tumor’s position. The axial breast contours and the segmented slices are ported to a custom-written MR-image contour analysis program, which generates a finite element model (FEM) input file readable by a commercial FEM software. A deformable silicon gel phantom was built to study the movements of an inclusion inside a deformable environment. The hyperelastic properties of the phantom materials were evaluated on an Instron Model 1331 mechanical testing machine. The phantom was placed in a custom-built pressure device, where a pressure plate caused a 14% (9.8mm) compression. The phantom was imaged in a 1.5T magnet (axial and coronal), in the undeformed and deformed states. An FEM of the phantom was built using the custom-written software from the MR data, and another FEM of the phantom was built using a commercial pre-processor from the phantom’s directly measured dimensions. The displacements of the inclusion center and its boundaries were calculated, both from the experimental and FEM results. The calculated displacements from both models are within 0.5mm of each other, and agree within 1.0mm with the experimental results. This difference is within the imaging error

Physiological effects of gonadotropin-releasing hormone immunocontraception on white-tailed deer

Before immunocontraceptives can be considered safe to use on wildlife species, potential health risks should be assessed. Gonadotropin-releasing hormone (GnRH) immunocontraceptive has successfully reduced fertility of white-tailed deer (Odocoileus virginianus); however, associated deer physiology has rarely been examined. We conducted gross necropsy examinations, histology, and blood chemistry comparisons on euthanized deer previously vaccinated with immunogenic GnRH (n = 18 females and n = 4 males), or left as untreated controls (n = 7 females and n = 6 males). Granulomas were found at injection sites of most deer, even 3 years post-treatment. There were no significant differences in ovary (F2,22= 0.31, P = 0.73), or pituitary weights (F2,22 = 0.30, P = 0.75) between treatment groups. Ovaries from control females had significantly more secondary follicles (F2,21 = 20.56, P ≤ 0.001), but not Graafi an follicles (F2,22= 2.22, P = 0.13). Immunized males had significantly lower mean testes weights, a number of morphologic abnormalities, and varying degrees of aspermatogenesis with fewer mature spermatozoa. We do not recommend treating male deer with anti-GnRH immunocontraceptive vaccines

Physiological effects of gonadotropin-releasing hormone immunocontraception on white-tailed deer

Before immunocontraceptives can be considered safe to use on wildlife species, potential health risks should be assessed. Gonadotropin-releasing hormone (GnRH) immunocontraceptive has successfully reduced fertility of white-tailed deer (Odocoileus virginianus); however, associated deer physiology has rarely been examined. We conducted gross necropsy examinations, histology, and blood chemistry comparisons on euthanized deer previously vaccinated with immunogenic GnRH (n = 18 females and n = 4 males), or left as untreated controls (n = 7 females and n = 6 males). Granulomas were found at injection sites of most deer, even 3 years post-treatment. There were no significant differences in ovary (F2,22= 0.31, P = 0.73), or pituitary weights (F2,22 = 0.30, P = 0.75) between treatment groups. Ovaries from control females had significantly more secondary follicles (F2,21 = 20.56, P ≤ 0.001), but not Graafi an follicles (F2,22= 2.22, P = 0.13). Immunized males had significantly lower mean testes weights, a number of morphologic abnormalities, and varying degrees of aspermatogenesis with fewer mature spermatozoa. We do not recommend treating male deer with anti-GnRH immunocontraceptive vaccines

Regional scale estimates of baseflow and factors influencing baseflow in the Upper Colorado River Basin

AbstractStudy regionThe study region encompasses the Upper Colorado River Basin (UCRB), which provides water for 40 million people and is a vital part of the water supply in the western U.S.Study focusGroundwater and surface water can be considered a single water resource and thus it is important to understand groundwater contributions to streamflow, or baseflow, within a region. Previously, quantification of baseflow using chemical mass balance at large numbers of sites was not possible because of data limitations. A new method using regression-derived daily specific conductance values with conductivity mass balance hydrograph separation allows for baseflow estimation at sites across large regions. This method was applied to estimate baseflow discharge at 229 sites across the UCRB. Subsequently, climate, soil, topography, and land cover characteristics were statistically evaluated using principal component analysis (PCA) to determine their influence on baseflow discharge.New hydrological insights for the regionResults suggest that approximately half of the streamflow in the UCRB is baseflow derived from groundwater discharge to streams. Higher baseflow yields typically occur in upper elevation areas of the UCRB. PCA identified precipitation, snow, sand content of soils, elevation, land surface slope, percent grasslands, and percent natural barren lands as being positively correlated with baseflow yield; whereas temperature, potential evapotranspiration, silt and clay content of soils, percent agriculture, and percent shrublands were negatively correlated with baseflow yield

Laboratory tests of oviposition by the African malaria mosquito, Anopheles gambiae, on dark soil as influenced by presence or absence of vegetation

BACKGROUND: Physical objects like vegetation can influence oviposition by mosquitoes on soil or water substrates. Anopheles gambiae s. l. is generally thought to utilize puddles over bare soil as its prime larval habitat and to avoid standing water populated with vegetation. In Kisian, Kenya near Kisumu, water often pools in grassy drainage areas both during and after periods of infrequent rains, when typical puddle habitats become scarce because of drying. This raised the question of whether An. gambiae has the behavioural flexibility to switch ovipositional sites when puddles over bare soil are unavailable. METHODS: To test whether presence and height of grasses influenced oviposition, wild-caught gravid An. gambiae s. l. were offered paired choices between wet, bare soil and wet soil populated with mixed grasses or grasses of differing height. No-choice tests were also conducted by giving females either grassy soil or bare soil. RESULTS: In choice tests, females laid four times more eggs on bare, wet soil than soil populated with grasses. However in no-choice tests, egg output was not significantly different whether grasses were present or not. Females laid significantly more eggs on soil populated with short grass than with medium, or tall grass. CONCLUSION: This work shows An. gambiae s. l. has the capacity to oviposit into grassy aquatic habitats when typical puddles over bare soil are unavailable. This knowledge will need to be considered in the design and implementation of programmes aimed at reducing malaria transmission by suppression of An. gambiae s. l. immatures