Location of hubs in a competitive environment

We offer a formulation that locates hubs on a network in a competitiveenvironment; that is, customer capture is sought, which happenswhenever the location of a new hub results in a reduction of thecurrent cost (time, distance) needed by the traffic that goes from thespecified origin to the specified destination.The formulation presented here reduces the number of variables andconstraints as compared to existing covering models. This model issuited for both air passenger and cargo transportation.In this model, each origin-destination flow can go through either oneor two hubs, and each demand point can be assigned to more than a hub,depending on the different destinations of its traffic. Links(``spokes'' have no capacity limit. Computational experience is provided.

Implementing interactive computing in an object-oriented environment

Statistical computing when input/output is driven by a Graphical User Interface is considered. A proposal is made for automatic control ofcomputational flow to ensure that only strictly required computationsare actually carried on. The computational flow is modeled by a directed graph for implementation in any object-oriented programming language with symbolic manipulation capabilities. A complete implementation example is presented to compute and display frequency based piecewise linear density estimators such as histograms or frequency polygons.

Agriculture and Environment Task Force Report To the Rebuild Iowa Advisory Commission, August 2008

The Rebuild Iowa Agriculture and Environment Task Force respectfully submits its report to the Rebuild Iowa Advisory Commission (RIAC) for consideration of the impacts of the tornadoes, storms, high winds, and flooding affecting Iowa’s agriculture sector and environment. The Task Force was required to address very complex and multi-faceted issues. Understanding that there were a broad range of immediate concerns, as well as critical issues that need to be addressed in the future, the Task Force structured its work in two sessions. To better address the issues and priorities of the Task Force, this report categorizes the issues as agriculture, conservation, environment, and livestock.

The effect of environment on development and survival of pupae of the necrophagous fly Ophyra albuquerquei Lopes (Diptera, Muscidae)

The effect of environment on development and survival of pupae of the necrophagous fly Ophyra albuquerquei Lopes (Diptera, Muscidae). Species of Ophyra Robineau-Desvoidy, 1830 are found in decomposing bodies, usually in fresh, bloated and decay stages. Ophyra albuquerquei Lopes, for example, can be found in animal carcasses. The influence of environmental factors has not been evaluated in puparia of O. albuquerquei. Thus, the focus of this work was motivated by the need for models to predict the development of a necrophagous insect as a function of abiotic factors. Colonies of O. albuquerquei were maintained in the laboratory to obtain pupae. On the tenth day of each month 200 pupae, divided equally into 10 glass jars, were exposed to the environment and checked daily for adult emergence of each sample. We concluded that the high survival rate observed suggested that the diets used for rearing the larvae and maintaining the adults were appropriate. Also, the data adjusted to robust generalized linear models and there were no interruptions of O. albuquerquei pupae development within the limits of temperatures studied in southern Rio Grande do Sul, given the high survival presented.

Comparison of human chromosome 21 conserved nongenic sequences (CNGs) with the mouse and dog genomes shows that their selective constraint is independent of their genic environment.

The analysis of conservation between the human and mouse genomes resulted in the identification of a large number of conserved nongenic sequences (CNGs). The functional significance of this nongenic conservation remains unknown, however. The availability of the sequence of a third mammalian genome, the dog, allows for a large-scale analysis of evolutionary attributes of CNGs in mammals. We have aligned 1638 previously identified CNGs and 976 conserved exons (CODs) from human chromosome 21 (Hsa21) with their orthologous sequences in mouse and dog. Attributes of selective constraint, such as sequence conservation, clustering, and direction of substitutions were compared between CNGs and CODs, showing a clear distinction between the two classes. We subsequently performed a chromosome-wide analysis of CNGs by correlating selective constraint metrics with their position on the chromosome and relative to their distance from genes. We found that CNGs appear to be randomly arranged in intergenic regions, with no bias to be closer or farther from genes. Moreover, conservation and clustering of substitutions of CNGs appear to be completely independent of their distance from genes. These results suggest that the majority of CNGs are not typical of previously described regulatory elements in terms of their location. We propose models for a global role of CNGs in genome function and regulation, through long-distance cis or trans chromosomal interactions.

Distribution and abundance of six species of fish larvae in peruvian waters and their relationship with physical and biological environment

Estudio de muestras recolectadas con el BIONESS a varias profundidades en trece estaciones.

DIGITAL LIBRARY FOR DIGITAL DIVIDE AND ENVIRONMENT OF SCARCE ACCESS TO PRINTED MATERIALS: THE CASE OF UNIVERSITY JEAN PIAGET OF CAPE VERDE

With the failure of the traditional mechanisms of distributing bibliographic materials into developing countries, digital libraries show up as a strong alternative in accomplishing such job, despite the challenges of the digital divide. This paper discusses the challenges of building a digital library (DL) in a developing country. The case of Cape Verde as a digital divide country is analyzed, in terms of current digital library usage and its potentiality for fighting the difficulties in accessing bibliographic resources in the country. The paper also introduces an undergoing project of building a digital library at the University Jean Piaget of Cape Verde.

Mother's attachment representations of their premature infant at 6 and 18 months after birth.

The effects of premature birth on attachment have generally been examined from the infant's perspective. There is a lack of data concerning parental attachment representations toward a premature child. Because of the psychological stress engendered in parents confronted with a premature birth, we hypothesized that their attachment representations would be altered during the first months after the hospital discharge. Fifty families with a premature infant (25-33 gestation weeks) and a control group of 30 families with a full-term infant participated to the study. Perinatal risks were evaluated during hospitalization. To assess mothers' representations of their infant, the Working Model of the Child Interview (WMCI, Zeanah & Benoit, 1995 & Benoit, Zeanah, Parker, Nicholson, & Coolbear, 1997) were administered when their children were 6 and 18 months old. The severity of the perinatal risks was found to have an impact on the mothers' attachment representations. At six months, only 20% of the mothers of a prematurely born infant (30% at 18 months) had secure attachment representations, vs. 53% for the control group (57% at 18 months). Furthermore, mothers of low-risk premature infants more often had disengaged representations, whereas distorted representations were more frequent in the high-risk group of premature children. These findings suggest that the parental response to a premature birth is linked to the severity of postnatal risks. The fact that secure attachment representations are affected in mothers of low-risk infants just as much as they are in mothers of high-risk infants points to the need to conduct further studies aimed at evaluating whether preventive intervention for both low-risk and high-risk premature will be helpful.

Energetic and metabolic cost of growth in Gambian infants.

The aim of the study was to measure the energy used for growth of healthy fullterm and breast-fed Gambian infants. The weight gain (WG) of 14 infants (mean age +/- SEM 17 +/- 1 d, weight 3.581 +/- 0.105 kg) was measured over a 2-week period; the energy intake (EI) from breast milk was assessed for 24 h in the middle of the study period by weighing the infant before and after each breast-feed. On the same day, sleeping energy expenditure (SEE) and respiratory quotient (RQ) were measured for 30 min on five occasions through the 24-h period. EI averaged 502 +/- 25 kJ/kg.d, and SEE 230 +/- 6 kJ/kg.d; thus, an average of 272 kJ/kg.d were available for physical activity and the energy stored for growth. The total energy spent by infants while sleeping and for periods of physical activity was calculated to be 1.7 x SEE. The mean RQ measured on five occasions averaged 0.879 +/- 0.009. SEE was correlated with WG (r = 0.747, P less than 0.005), with a slope of the regression line of 5.5 kJ/g; this value can be considered as an estimate of the energy spent for new tissue synthesis in the resting infant. The efficiency of weight gain was lower in this study (67%) than in studies conducted on fast-growing preterm infants or children recovering from malnutrition.

Low-pressure environment and remodelling of the forearm vein in Brescia-Cimino haemodialysis access.

BACKGROUND: The aim of the study was to determine which, and to what extent, haemodynamic parameters contribute to the remodelling of the venous limb of the Brescia-Cimino haemodialysis access. METHODS: The dimensions of the radial artery and the venous limb of the haemodialysis access were measured by an echo-tracking technique. In six ESRD patients undergoing primary arteriovenous fistula (AVF) formation, vessel diameter, wall thickness, blood pressure and blood flow were measured after the operation, and at 1 and 3 months follow-up. The contralateral forearm vessels in their native position served as baseline values for comparison. RESULTS: The diameter of the proximal antecubital vein progressively increased over the study period without reaching significant differences (4430, 5041 and 6620 microm at weeks 1, 4 and 12 respectively), whereas the intima-media thickness remained unchanged. The venous dilatation was associated with a reduction of the mean shear stress that culminated after the operation and progressively returned to normal venous values at 3 months (24.5 vs 10.4 dyne/cm(2), P<0.043). Thus the venous limb of the AVF undergoes eccentric hypertrophy as demonstrated by the increase in wall cross-sectional area (4.42 vs 6.32 mm(2) at week 1 vs week 12, P<0.028). At the time of the operation, the blood pressure in the AVF was 151+/-14/92.4+/-11 mmHg vs 49+/-19/24.5+/-6 mmHg (means+/-SEM) for the radial artery and the venous limb of the vascular access, respectively. One year after the operation the blood pressure in the venous limb had not changed: 42+/-14/25.3+/-7 mmHg (means+/-SEM). Under these conditions, the systolo-diastolic diameter changes observed in the radial artery and the antecubital vein were within a similar range at all time points: 56+/-17 vs 90+/-26 microm (means+/-SEM) at week 12. CONCLUSIONS: The increased circumferential stress resulting from the flow-mediated dilatation rather than the elevation of blood pressure appears to represent the main contributing factor to the eccentric hypertrophy of the venous limb of Brescia-Cimino haemodialysis access.

Stable isotope compositions of mammoth teeth from Niederweningen, Switzerland: Implications for the Late Pleistocene climate, environment, and diet

Oxygen and carbon isotope compositions of well-preserved mammoth teeth from the Middle Wurmian (40-70 ka) peat layer of Niederweningen, the most important mammoth site in Switzerland, were analysed to reconstruct Late Pleistocene palaeoclimatic and palaeoenvironmental conditions. Drinking water (delta(18)O values of approximately -12.3 +/- 0.9 parts per thousand were calculated front oxygen isotope compositions of mammoth tooth enamel apatite using a species-specific calibration for modern elephants. These delta(18)O(H2O) values reflect the mean oxygen isotope composition of the palaeo-precipitation and are similar to those directly measured for fate Pleistocene groundwater from aquifers in northern Switzerland and southern Germany. Using a present-day delta(18)O(H2)o-precipitation-air temperature relation for Switzerland, a mean annual air temperature (MAT) of around 4.3 +/- 2.1 degrees C can be calculated for the Middle Wurmian at this site. This MAT is in good agreement with palaeotemperature estimates on the basis of Middle Wurmian groundwater recharge temperatures and beetle assemblages. Hence, the climatic conditions in this region were around 4 degrees C cooler during the Middle Wurmian interstadial phase, around 45-50ka BP, than they are today. During this period the mammoths from Niederweningen lived in an open tundra-like, C(3) plant-dominated environment as indicated by enamel (delta(13)C values of -11.5 +/- 0.3 parts per thousand and pollen and macroplant fossils found in the embedding peat. The low variability of enamel delta(13)C and delta(18)O values from different mammoth teeth reflects similar environmental conditions and supports a relatively small time frame for the fossil assemblage. (C) 2006 Elsevier Ltd and INQUA. All rights reserved.

The impact of eliminating a child benefit on birth timing and infant health

We study the effects of the cancellation of a sizeable child benefit in Spainon birth timing and neonatal health. In May 2010, the government announced that a2,500-euro universal "baby bonus" would stop being paid to babies born startingJanuary 1, 2011. We use detailed micro data from birth certificates from 2000 to 2011,and find that more than 2,000 families were able to anticipate the date of birth of theirbabies from (early) January 2011 to (late) December 2010 (for a total of about 10,000births a week nationally). This shifting took place in part via an increase as well as ananticipation of pre-programmed c-sections, seemingly mostly in private clinics. We findthat this shifting of birthdates resulted in a significant increase in the number ofborderline low birth weight babies, as well as a peak in neonatal mortality. The resultssuggest that announcement effects are important, and that families and healthprofessionals may face effective trade-offs when deciding on the timing (and method) ofbirth.