138 research outputs found
Typical properties of optimal growth in the Von Neumann expanding model for large random economies
We calculate the optimal solutions of the fully heterogeneous Von Neumann
expansion problem with processes and goods in the limit .
This model provides an elementary description of the growth of a production
economy in the long run. The system turns from a contracting to an expanding
phase as increases beyond . The solution is characterized by a universal
behavior, independent of the parameters of the disorder statistics. Associating
technological innovation to an increase of , we find that while such an
increase has a large positive impact on long term growth when , its
effect on technologically advanced economies () is very weak.Comment: 8 pages, 1 figur
Chemical composition and quality loss during technological treatment in coho salmon (Oncorhynchus kisutch)
Coho salmon (Oncorhynchus kisutch) supports an important farming production
in parallel with capture delivery, giving rise to products of great economic importance
in many countries. This review covers the research carried out during the last decades
related to its employment as a food product. In a first part, studies carried out
concerning the chemical constituent composition and nutritional value are reviewed; a
special attention is accorded to the wild/ farmed fish comparison and to the effect of diet
on lipid composition variations. In agreement to the great lability of chemical
constituents of aquatic foods, the second part of the manuscript provides a revision of
coho salmon research related to the chemical component changes produced during
technological processing and their effects on nutritional and sensory losses; in this case,
a special attention is accorded to studies employing advanced technological strategies
focused to partially inhibit the development of the different damage pathways.support provided by the Universidad de Chile (Chile)-
Consejo Superior de Investigaciones CientĂficas (CSIC, Spain) research program
through the following projects: Project 2003 CL 0013, Project 2004 CL 0038 and
Project 2006 CL 0034.
43Peer reviewe
Limitations of Dutch Growth Research Foundation Commercial Software Weight Velocity for Age Standard Deviation Score
BACKGROUND The commercial software for hospitals, Weight Velocity for Age Standard Deviation Score (SDSWVA), claims to document the growth and development of children, although published details are unavailable. The statistics-derived parameter SDSWVA includes the weight velocity at age t, WV(t) (weight gained between t and (t-1.23) years, divided by 1.23), and 3 standard weight velocity curves at average age AA, defined as AA=t-1.23/2 years. SDSWVA denotes the number of standard deviations that WV(t) deviates from the 0 SD weight velocity at AA. WV(t) yielded erroneous outcomes when applied to weights of a seriously underweight boy with an allergy to cows' milk who showed strong weight growth after being fed on food free of cows' milk. The SDSWVA software tacitly suggests that it is more accurate than WV(t). CASE REPORT The case of this boy was previously described in this Journal. Using SDSWVA(t,AA) software, his weight growth was analyzed by his third pediatrician, beginning at age 1.5 years. The diagnosis of the mother with Pediatric Condition Falsification was confirmed, adding 6 months to foster care, which totalled 8.5 months. Testing of the SDSWVA software on the boy's weight curve yielded results that were complex, nontransparent, and as erroneous as WV(t), explaining the misdiagnosis by the third pediatrician. CONCLUSIONS SDSWVA software should not be used for children under 3 years and during variable weight behavior. Erroneous performance, unpublished details, and an error identified in their new but untested software make the Dutch Growth Research Foundation unlikely to meet the 2020 European Union regulations for in vitro medical devices
Limitations of Weight Velocity Analysis by Commercial Computer Program Growth Analyser Viewer Edition
Commercial software package âGrowth Analyser Viewer Editionâ (âGAVEâ) aims to document, monitor and analyze growth and development in children and adolescents. Although its clinical and scientific use is widespread, there are no published studies that describe the method and its validation. We were informed that GAVE calculates the weight velocity (kg/year) at age t from the weight difference between t and 448Â days earlier or at birth, divided by the time difference. We recently discussed a case of false child abuse diagnosis (Pediatric Condition Falsification), resulting in the separation of the child from its parents, in which GAVE played a negative contributing role. To prevent such inappropriate diagnoses, we analyzed GAVE from a schematic representation of the measured clinical weight curve, with precisely defined weight velocities. In conclusion, the 448Â days included for weight velocity predictions by GAVE caused the erroneous outcomes. Until the necessary changes to the software are implemented and validated, we advise against the use of GAVE in infants younger than 1.5Â years, if multiple weight changes occur within 448Â days, and following a long-lasting weight velocity change. Our analysis suggests to discard all medical software packages that lack public description and proof of validation
Limitations of Weight Velocity Analysis by Commercial Computer Program Growth Analyser Viewer Edition
Commercial software package âGrowth Analyser Viewer Editionâ (âGAVEâ) aims to document, monitor and analyze growth and development in children and adolescents. Although its clinical and scientific use is widespread, there are no published studies that describe the method and its validation. We were informed that GAVE calculates the weight velocity (kg/year) at age t from the weight difference between t and 448Â days earlier or at birth, divided by the time difference. We recently discussed a case of false child abuse diagnosis (Pediatric Condition Falsification), resulting in the separation of the child from its parents, in which GAVE played a negative contributing role. To prevent such inappropriate diagnoses, we analyzed GAVE from a schematic representation of the measured clinical weight curve, with precisely defined weight velocities. In conclusion, the 448Â days included for weight velocity predictions by GAVE caused the erroneous outcomes. Until the necessary changes to the software are implemented and validated, we advise against the use of GAVE in infants younger than 1.5Â years, if multiple weight changes occur within 448Â days, and following a long-lasting weight velocity change. Our analysis suggests to discard all medical software packages that lack public description and proof of validation
Heat conduction from the exceedingly hot fiber tip contributes to the endovenous laser ablation of varicose veins
Lower-extremity venous insufficiency is a common condition, associated with considerable health care costs. Endovenous laser ablation is increasingly used as therapy, but its mechanism of action is insufficiently understood. Here, direct absorption of the laser light, collapsing steam bubbles and direct fiber-wall contact have all been mentioned as contributing mechanisms. Because fiber tips have reported temperatures of 800-1,300°C during endovenous laser ablation, we sought to assess whether heat conduction from the hot tip could cause irreversible thermal injury to the venous wall. We approximated the hot fiber tip as a sphere with diameter equal to the fiber diameter, having a steady state temperature of 800°C or 1,000°C. We computed venous wall temperatures due to heat conduction from this hot sphere, varying the pullback velocity of the fiber and the diameter of the vein. Venous wall temperatures corresponding to irreversible injury resulted for a 3 mm diameter vein and pullback velocities <3 mm/s but not for 5 mm and 1 mm/s. The highest wall temperature corresponded to the position on the wall closest to the fiber tip, hence it moves longitudinally in parallel with the moving fiber tip. We concluded that heat conduction from the hot fiber tip is a contributing mechanism in endovenous laser ablation
The heat-pipe resembling action of boiling bubbles in endovenous laser ablation
Endovenous laser ablation (EVLA) produces boiling bubbles emerging from pores within the hot fiber tip and traveling over a distal length of about 20 mm before condensing. This evaporation-condensation mechanism makes the vein act like a heat pipe, where very efficient heat transport maintains a constant temperature, the saturation temperature of 100°C, over the volume where these non-condensing bubbles exist. During EVLA the above-mentioned observations indicate that a venous cylindrical volume with a length of about 20 mm is kept at 100°C. Pullback velocities of a few mm/s then cause at least the upper part of the treated vein wall to remain close to 100°C for a time sufficient to cause irreversible injury. In conclusion, we propose that the mechanism of action of boiling bubbles during EVLA is an efficient heat-pipe resembling way of heating of the vein wall
Novel insights into host-fungal pathogen interactions derived from live-cell imaging
Acknowledgments The authors acknowledge funding from the Wellcome Trust (080088, 086827, 075470 and 099215) including a Wellcome Trust Strategic Award for Medical Mycology and Fungal Immunology 097377 and FP7-2007â2013 grant agreement HEALTH-F2-2010-260338âALLFUN to NARG.Peer reviewedPublisher PD
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