NETWORK SCHEDULING LIMITED BY SPECIAL CONSTRAINT AS A FUNCTION OF TIME COST

The paper deals with the application of mathematical programming techniques to network analysis and network management in general. The authors show the application of linear programming to network scheduling when the problem is to minimize the total crashing cost and the required completion time is given. Finally the application of goal programming is presented in network scheduling in tha case, when all kinds of constraints (time, resource, etc.) are introduced into the problem and the manager has to deal with multiple objectives which may be in conflict. All kinds of network scheduling problems mentioned above are illustrated through a detailed numerical example

Effects of Salt Stress on Three Ecologically Distinct Plantago Species

Comparative studies on the responses to salt stress of taxonomically related taxa should help to elucidate relevant mechanisms of stress tolerance in plants. We have applied this strategy to three Plantago species adapted to different natural habitats, P. crassifolia and P. coronopus both halophytes and P. major, considered as salt-sensitive since it is never found in natural saline habitats. Growth inhibition measurements in controlled salt treatments indicated, however, that P. major is quite resistant to salt stress, although less than its halophytic congeners. The contents of monovalent ions and specific osmolytes were determined in plant leaves after four-week salt treatments. Salt-treated plants of the three taxa accumulated Na+ and Cl- in response to increasing external NaCl concentrations, to a lesser extent in P. major than in the halophytes; the latter species also showed higher ion contents in the non-stressed plants. In the halophytes, K+ concentration decreased at moderate salinity levels, to increase again under high salt conditions, whereas in P. major K+ contents were reduced only above 400 mM NaCl. Sorbitol contents augmented in all plants, roughly in parallel with increasing salinity, but the relative increments and the absolute values reached did not differ much in the three taxa. On the contrary, a strong (relative) accumulation of proline in response to high salt concentrations (600 800 mM NaCl) was observed in the halophytes, but not in P. major. These results indicate that the responses to salt stress triggered specifically in the halophytes, and therefore the most relevant for tolerance in the genus Plantago are: a higher efficiency in the transport of toxic ions to the leaves, the capacity to use inorganic ions as osmotica, even under low salinity conditions, and the activation, in response to very high salt concentrations, of proline accumulation and K+ transport to the leaves of the plants.MAH was a recipient of an Erasmus Mundus pre-doctoral scholarship financed by the European Commission (Welcome Consortium). AP acknowledges the Erasmus mobility programme for funding her stay in Valencia to carry out her Master Thesis.Al Hassan, M.; Pacurar, AM.; López Gresa, MP.; Donat Torres, MDP.; Llinares Palacios, JV.; Boscaiu Neagu, MT.; Vicente Meana, Ó. (2016). Effects of Salt Stress on Three Ecologically Distinct Plantago Species. PLoS ONE. 11(8):1-21. doi:10.1371/journal.pone.0160236S12111

Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

Contains fulltext : 172380.pdf (publisher's version ) (Open Access

Correlation of contrast-enhanced ultrasound kinetics with prognostic factors in invasive breast cancer

OBJECTIVES: To correlate contrast-enhanced ultrasound (CEUS) kinetic parameters with traditional and molecular prognostic factors in invasive breast cancer. METHODS: Seventy-five invasive breast cancers were evaluated with contrast harmonic imaging after the injection of a bolus dose of 2.4 ml sulphur hexafluoride microbubble contrast agent. The lognormal function was used for quantitative analysis of kinetic data. These parameters correlated with traditional prognostic factors (tumour size, histological type, tumour grade, axillary lymph node status) and immunohistochemical biomarkers (ER, PR and HER2 status). RESULTS: Statistically significant correlation was found between time-to-peak and tumour grade (P value = 0.023), PR status (P value = 0.042) and axillary node status (P value = 0.025). Wash-out ratio, measured at 21 s was significantly associated with ER status (P value = 0.042) and PR status (P value = 0.026). CONCLUSIONS: Invasive breast carcinomas exhibiting earlier peak enhancement and faster elimination of microbubble contrast agent at CEUS are found to be associated with established predictors of poor prognosis. KEY POINTS: * Contrast-enhanced ultrasound (CEUS) can potentially determine the aggressiveness of invasive breast cancers. * Early peak enhancement and accelerated wash-out at CEUS suggest poor prognosis. * CEUS kinetics are similar to that of DCE-MRI in assessing tumour aggressiveness

Contrast-enhanced ultrasound (CEUS) in assessing early response among patients with invasive breast cancer undergoing neoadjuvant chemotherapy

Background One of the big challenges in onco-radiology is to find a reliable imaging method that may predict early response during the first cycles of any neoadjuvant chemotherapy. Purpose To evaluate the use of real-time harmonic contrast-enhanced ultrasound (CEUS) in predicting early response in breast cancer tumors under neoadjuvant chemotherapy (NAC) treatment. Material and Methods Nineteen consecutive patients with invasive breast cancer were evaluated with a bolus dose of 2.4 mL contrast agent using CEUS, before and after two cycles of epirubicin and docetaxel. The lognormal function was used for quantitative analysis of kinetic data to evaluate early response. Results There was statistically significant difference in time-to-peak ( tp) between responders and non-responders (two sample t-test, P = 0.027) where tp was significantly longer at the week 5 than at the baseline scan among responders when compared to non-responders. Conclusion In-flow of intravascular contrast agent in tumors is significantly slower in responders at real-time harmonic CEUS, and might be effectively used for the evaluation of early response to chemotherapy in invasive breast cancer. However, further investigations in a larger and more heterogeneous population should be performed to corroborate the reliability of the method

Contrast-enhanced ultrasound using real-time contrast harmonic imaging in invasive breast cancer: comparison of enhancement dynamics with three different doses of contrast agent

Background: In the last few years new potential applications have been developed for contrast-enhanced ultrasound (CEUS) and the management of breast diseases, but there is still some debate concerning the optimal dose to evaluate breast lesions, especially as a diagnostic tool. Purpose: To compare different CEUS doses of injected contrast agent in order to establish an optimal dose for the diagnosis of invasive breast cancer. Material and Methods: In Group A we compared the bolus dose of 1.2 mL vs. 2.4 mL and in Group B we compared the bolus dose of 2.4 mL vs. 4.8 mL (26 and 25 invasive carcinomas, respectively). CEUS was performed in real-time contrast harmonic imaging (CHI) using a L9-3 MHz probe. All examinations were recorded in a contrast side/side imaging mode loop for 120 s. Wash-in and wash-out patterns of the contrast agent were analyzed with advanced US quantification software and kinetic curves were used for statistical analysis. Results: In Group B (2.4 mL vs. 4.8 mL), more and stronger correlation was found among kinetic parameters (area under the curve, P< 0.00001; lognormal model parameters, mu, P = 0.0007 and sigma, P< 0.0001; mean transit time, P< 0.0001; model-based wash-out ratios, W-21m, P = 0.0002; W-50m, P = 0.0001; time-to-peak, P = 0.005) as compared to Group A (1.2 mL vs. 2.4 mL). Conclusion: The optimal way to evaluate kinetic features of invasive breast tumors using real-time CEUS is with an injection of contrast agent of either 2.4 mL or 4.8 mL