1,342 research outputs found

    The international trade as the sole engine of growth for an economy

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    Can international trade act as the sole engine of growth for an economy? If yes, what are the mechanisms through which trade operates in transmitting permanent growth? This paper answers these questions with two simple two-country models, in which only one country enjoys sustained growth in autarky. The models differ in the assumptions on technical change, which is either labour- or capital-augmenting. In both cases, the stagnant economy imports growth by trading. In the first model, growth is transmitted because of permanent increases in the trade volume. In the alternative framework, the stagnant economy imports sustained growth because its terms of trade permanently improve.international trade; stagnant economies; growth transmission; mechanisms of transmission.

    Change of sea level trend in the Mediterranean and Black seas

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    Sea level anomaly (SLA) data in the Mediterranean and Black seas obtained by ocean radar altimetry missions (TOPEX/Poseidon, Jason, ERS-1/2 and ENVISAT) are studied in conjunction with corresponding sea-surface temperature (SST) data. The studied time span is 11 years long, 1993-2003. Besides confirming previously published results, we report a significant, but enigmatic, abrupt change in the SLA trend that took place in mid-1999 which has been corroborated by independent tide gauge data. Results obtained from an Empirical Orthogonal Function (EOF) analysis show that the change in 1999 is not uniform in the Mediterranean Sea, which can thus be divided into 6 sub-regions. This 1999 kink in the rate-of-change happened in four of these sub-regions as well as in the Black Sea. Upon splitting the time series at mid-1999, we see a good spatial correlation for the first period between SLA and SST trend maps in both the Mediterranean Sea and the Black Sea, while for the second period such correlation virtually disappeared in the Mediterranean and is greatly reduced in the Black Sea. It implies that prior to 1999 the steric effect was a major factor in interannual variability of sea level in the Mediterranean and Black seas, but after the time the SLA inverted its trend in mid-1999, this steric effects became less important as a forcing factor. It is premature to draw conclusions about the physical processes involved based on the data sets we study, but it appears that the Mediterranean Sea might be seeing a restoration of Adriatic as the main source of deep water in the eastern basin, while the Black Sea level has been largely controlled by an interannual or interdecadal steric effect

    An exact approach for the vehicle routing problem with two-dimensional loading constraints

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    We consider a special case of the symmetric capacitated vehicle routing problem, in which a fleet of K identical vehicles must serve n customers, each with a given demand consisting in a set of rectangular two-dimensional weighted items. The vehicles have a two-dimensional loading surface and a maximum weight capacity. The aim is to find a partition of the customers into routes of minimum total cost such that, for each vehicle, the weight capacity is taken into account and a feasible two-Dimensional allocation of the items into the loading surface exists. The problem has several practical applications in freight transportation, and it is -hard in the strong sense. We propose an exact approach, based on a branch-and-cut algorithm, for the minimization of the routing cost that iteratively calls a branch-and-bound algorithm for checking the feasibility of the loadings. Heuristics are also used to improve the overall performance of the algorithm. The effectiveness of the approach is shown by means of computational results

    Cardiovascular Endurance Among College Students: How is it Related to Overall Fitness?

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    Please see the pdf version of the abstract

    Barium alginate capsules for 3D immobilisation of living cells: morphology, membrane properties and permeability

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    Encapsulation in a barium alginate membrane is a promising strategy to obtain a three dimensional culture of living cells: membrane properties are crucial for a realistic clinical application. A one-step encapsulation technique, recently developed for controlled release of boar semen, was employed to prepare barium alginate and protamine-alginate membranes: permeability to two model molecules (haemoglobin and glucose) was evaluated. Capsules were evaluated for technological properties and scanning electron microscopy was used to examine the external morphology of the capsules and the 3D distribution of the cells within the core. The results indicate that 3D arrangement and cell shape are maintained, capsule dimensions and mechanical properties can be modulated, as well as their permeability to model molecules such as haemoglobin and glucose

    Owner and animal factors predict the incidence of, and owner reaction towards, problem behaviors in companion dogs

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    Unwelcome behaviors in pet dogs may have serious implications for the quality of life of both the animals and their owners. We investigated owners\u2019 perceptions about their dogs\u2019 behavioral issues as well as other factors that might be predictive of potential canine problem behaviors. We distinguished between \u201cundesirable behaviors\u201d (behaviors that were unpleasant to the owners) and \u201cproblematic behaviors\u201d (behaviors that the owners found difficult to overcome). We designed an on-line survey eliciting information about owners, their dogs, their relationship with their dogs and whether the animals exhibited any of 15 potentially problematic behaviors. The largest proportion of respondents (65%) reported that their dogs exhibited undesirable, but not problematic, behaviors and were not interested in their modification. Only 32% of the respondents considered the behavior to be both undesirable and problematic and wished to change it. The owners\u2019 perception of a problem was associated with reports of fear- and anxiety-related behaviors. The owner\u2019s gender, marital status and attitude towards the dog as his/her child as well as the dog\u2019s age, size, age at acquisition and breed emerged as robust predictors. Compared to all other behavioral categories, reported aggressive canine behaviors were three times more likely to elicit an owner\u2019s wish to address them. This study revealed that the behaviors of dogs may be perceived differently by their owners and the type of perception may influence the owner\u2019s actual willingness to change those behaviors. Moreover, we identified the most robust set of factors that, either individually or combined, would help predict a dog\u2019s potential problem behaviors and an owner\u2019s attitude towards them, which will be useful in improving rational prevention and treatment strategies

    District heating network maintenance planning optimization

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    To ensure the correct functioning of district heating networks and minimize critical failures, utilities allocate every year a significant part of their budget to maintenance operations. In the present work we describe a risk-based approach implemented to tackle the problem of designing optimal multi-year maintenance campaigns, applied to the Italian city of Brescia, showing how data-driven techniques can help decision makers assess the long terms impacts of budget allocations
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