An intertemporal model of consumption and portfolio allocation

We develop an infinite time horizon, continuous time model of portfolio choice and consumption allocation for an investor seeking to maximize the expected utility of his life-time consumption. In this model, the investor is endowed with capital that can be invested in long-lived capital assets and has, in addition, a stochastic stream of cash flows that could be interpreted as either a wage income stream or a stochastic endowment flow. We obtain a complete and original solution to the consumption-portfolio choice problem for the negative exponential and quadratic utility functions and special case solutions for the general power and log utility functions. The results obtained in this paper have significant implications for the theory of asset prices, the theory of mutual funds, optimal portfolio strategies of investors, and so forth. The results of the model can also be easily extended to one with a finite time horizon

Off-farm Income and Risky Investments: What Happens to Farm and Nonfarm Assets?

Off-farm work improves and reduces the riskiness of household income. Theoretical analyses reveal that the level and riskiness of off-farm income affect demand for farm/nonfarm investments. A two-limit Tobit model is estimated using ARMS data for 1996-2003. The impact on investment behaviour is evaluated.Farm Management,

Off-farm income and risk reduction in agriculture: when does it matter?

Investment behavior is analyzed using a dynamic portfolio model including off-farm income. The correlation structure of off-farm income and asset returns and the ratio of off-farm income to wealth is shown to affect portfolio choice. Empirical analysis indicates that off-farm income tends to increase farm assets

Editorial : Genetics of familial hypercholesterolemia: New insight-Volume II

Non peer reviewe

Quadrilateral meshes with provable angle bounds

In this paper, we present an algorithm that utilizes a quadtree data structure to construct a quadrilateral mesh for a simple polygonal region in which no newly created angle is smaller than 18.43∘(=arctan(13)) or greater than 171.86∘(=135∘+2arctan(13)). This is the first known result, to the best of our knowledge, on a direct quadrilateral mesh generation algorithm with a provable guarantee on the angles

Editorial: Genetics of Familial Hypercholesterolemia: New Insight

Non peer reviewe

Quadrilateral meshes with provable angle bounds

In this paper, we present an algorithm that utilizes a quadtree data structure to construct a quadrilateral mesh for a simple polygonal region in which no newly created angle is smaller than 18.43∘(=arctan(13)) or greater than 171.86∘(=135∘+2arctan(13)). This is the first known result, to the best of our knowledge, on a direct quadrilateral mesh generation algorithm with a provable guarantee on the angles

Off-farm income and risk reduction in agriculture: when does it matter?

Investment behavior is analyzed using a dynamic portfolio model including off-farm income. The correlation structure of off-farm income and asset returns and the ratio of off-farm income to wealth is shown to affect portfolio choice. Empirical analysis indicates that off-farm income tends to increase farm assets.Agriculture ; Farm income ; Wages

Endovascular stent grafting in the presence of aortic neck filling defects: Early clinical experience

AbstractObjective: Although endovascular grafts have been increasingly applied to the treatment of abdominal aortic aneurysms, their use in clinical trials is limited by well-defined anatomical exclusion criteria. One such criterion is the presence of thrombus within the infrarenal neck of an aneurysm, which is thought to (1) prevent the creation of a permanent watertight seal between the graft and the vessel wall, resulting in an endoleak; (2) contribute to stent migration; and (3) increase the risk of thromboembolism. This article summarizes our experience with endovascular abdominal aortic aneurysm exclusion in 19 patients with large aortic aneurysms, significant medical comorbidities, and apparent thrombus extending into the pararenal aortic neck. Methods: Of 268 patients undergoing abdominal aortic aneurysm repair, 19 (7%; 17 men; mean age, 71 years) demonstrated computed tomographic and angiographic evidence of intramural filling defects at the level of the aortic neck. In no instance did these filling defects extend above the renal arteries. Endovascular grafting was performed through use of a balloon-expandable Palmaz stent and an expanded polytetrafluoroethylene graft, delivered and deployed under fluoroscopic guidance. Follow-up at 3, 6, and 12 months and annually thereafter was performed with computed tomography and duplex ultrasound scan. Results: Spiral computed tomography and aortography revealed an irregular flow-limiting defect, occupying up to 75% of the aortic circumference, in every case. The mean aneurysm size, aortic neck diameter, and neck length before the procedure were 6.1, 2.43, and 1.4 cm, respectively; the mean aortic neck diameter after the procedure was 2.61 cm. No primary endoleaks were observed after graft insertion, and no delayed endoleaks have been detected during follow-up, which ranged from 7 to 48 months (mean, 23 months). In one patient, an asymptomatic renal artery embolus was detected on immediate follow-up computed tomography, and in another patient, an asymptomatic posterior tibial embolus occurred. Conclusion: No primary endoleaks, endograft migration, or significant distal embolization were observed after endografting in patients with aortic neck thrombus. The deployment of the fenestrated portion of the stent, above the thrombus and across the renal arteries, allows for effective renal perfusion, graft fixation, and exclusion of potential mural thrombus from the circulation. The presence of aortic neck thrombus may not necessarily be a contraindication to endovascular repair in select patients. (J Vasc Surg 2001;33:340-4.