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Increasing concentrations of atmospheric particles are expected to impact Northern Hemisphere mid-latitude precipitation and temperature. This study finds that there is little evidence that aerosol concentrations affect land precipitation in the region, which they attribute to changes in observational techniques that increased measured values at the time aerosols were expected to suppress precipitation.

[1] To the extent that deficiencies in GCM simulations of precipitation are due to persistent errors of location and timing, correcting the spatial and seasonal distribution of features would provide a physically based improvement in inter-model agreement on future changes. We use a tool for the analysis of medical images to warp the precipitation climatologies of 14 General Circulation Models (GCMs) closer to a reanalysis of observations, rather than adjusting intensities locally as in conventional bias correction techniques. These warps are then applied to the same GCMs' simulated changes in mean climate under a CO2 quadrupling experiment. We find that the warping process not only makes GCMs' historical climatologies more closely resemble reanalysis but also reduces the disagreement between the models' response to this external forcing. Developing a tool that is tailored for the specific requirements of climate fields may provide further improvement, particularly in combination with local bias correction techniques.

A perennial question in modern weather forecasting and climate prediction is whether to invest resources in more complex numerical models or in larger ensembles of simulations. If this question is to be addressed quantitatively, then information is needed about how changes in model complexity and ensemble size will affect predictive performance. Information about the effects of ensemble size is often available, but information about the effects of model complexity is much rarer. An illustration is provided of the sort of analysis that might be conducted for the simplified case in which model complexity is judged in terms of grid resolution and ensemble members are constructed only by perturbing their initial conditions. The effects of resolution and ensemble size on the performance of climate simulations are described with a simple mathematical model, which is then used to define an optimal allocation of computational resources for a range of hypothetical prediction problems. The optimal resolution and ensemble size both increase with available resources, but their respective rates of increase depend on the values of two parameters that can be determined from a small number of simulations. The potential for such analyses to guide future investment decisions in climate prediction is discussed.

Previous work has demonstrated that observed and modeled climates show a near-time-invariant ratio of mean land to mean ocean surface temperature change under transient and equilibrium global warming. This study confirms this in a range of atmospheric models coupled to perturbed sea surface temperatures (SSTs), slab (thermodynamics only) oceans, and a fully coupled ocean. Away from equilibrium, it is found that the atmospheric processes that maintain the ratio cause a land-to-ocean heat transport anomaly that can be approximated using a two-box energy balance model. When climate is forced by increasing atmospheric CO2 concentration, the heat transport anomaly moves heat from land to ocean, constraining the land to warm in step with the ocean surface, despite the small heat capacity of the land. The heat transport anomaly is strongly related to the top-of-atmosphere radiative flux imbalance, and hence it tends to a small value as equilibrium is approached. In contrast, when climate is forced by prescribing changes in SSTs, the heat transport anomaly replaces “missing” radiative forcing over land by moving heat from ocean to land, warming the land surface. The heat transport anomaly remains substantial in steady state. These results are consistent with earlier studies that found that both land and ocean surface temperature changes may be approximated as local responses to global mean radiative forcing. The modeled heat transport anomaly has large impacts on surface heat fluxes but small impacts on precipitation, circulation, and cloud radiative forcing compared with the impacts of surface temperature change. No substantial nonlinearities are found in these atmospheric variables when the effects of forcing and surface temperature change are added.

A tropospheric energy budget argument is used to analyze twentieth-century precipitation changes. It is found that global and ocean-mean general circulation model (GCM) precipitation changes can be understood as being due to the competing direct and surface-temperature-dependent effects of external climate forcings. In agreement with previous work, precipitation is found to respond more strongly to anthropogenic and volcanic sulfate aerosol and solar forcing than to greenhouse gas and black carbon aerosol forcing per unit temperature. This is due to the significant direct effects of greenhouse gas and black carbon forcing. Given that the relative importance of different forcings may change in the twenty-first century, the ratio of global precipitation change to global temperature change may be quite different. Differences in GCM twentieth- and twenty-first-century values are tractable via the energy budget framework in some, but not all, models. Changes in land-mean precipitation, on the other hand, cannot be understood at all with the method used here, even if land–ocean heat transfer is considered. In conclusion, the tropospheric energy budget is a useful concept for understanding the precipitation response to different forcings but it does not fully explain precipitation changes even in the global mean.

The paper focuses on testing comparative evaluation of fatigue performance of composite asphalt pavement layers constructed at the Turner-Fairbank Highway Research Center (T-F) under full-scale trafficking with the ALF and the one third scaled MMLS3 (also known as MLS 11, since January 2015) of Virginia Tech in Blacksburg. The goal was to enhance economics of APT testing. Virgin 100 mm asphalt slabs of the composite 50 mm dual layers were extracted from the in situ un-trafficked sections of the test lanes after unidirectional testing with the ALF using a formalized process. The process was developed to overcome constraints due to traffic and temperature control as well as minimizing logistics during field testing. After extraction, the slabs were transported by vehicle to Blacksburg, VA where the MMLS3 testing procedure was formalized by means of a proof test on the lower 50 mm of a slab from Lane 9. For this, a 25 mm neoprene slab was used as interlayer between the asphalt and the underlying in situ concrete floor. After successful completion of the proof test, four further tests were completed. Two were done on the extractions from Lane 9B and 9A, and the other two were done on the extraction from Lane 5. The latter three tests all had two 25 mm neoprene interlayers. Aspects that were considered in the comparative evaluations were rutting, strain response, seismic stiffness using the Portable Seismic Pavement Analyzer (PSPA), cracking and contact stress under the MMLS tire. The effects of the respective material characteristics were also discussed. From the findings it was concluded that the monitored parameters found from the scaled tests were comparable to the related full-scale ALF test results in terms of intrinsic material characteristics and pavement performance. This is similar to earlier reported comparative studies. The authors consider this finding to be an economic benefit that should be utilized in pavement engineering studies.

The National Academies sponsored a series of three APT Syntheses since 1996. The last synthesis was conducted in 2011. This was followed by the fourth, most recent international APT conference that was held in Davis, California in 2012. It is thus now an opportune time to look back at the information identified in these syntheses, the trends predicted and the actual development since 2011. The paper starts with a brief evaluation of the trends identified in the 2011 synthesis, identifying those that were deemed to be new and receiving attention in the immediate future. This is compared to the APT work published in the last 5 years to compare the generation of new knowledge in the area of APT, and a discussion and analysis of the trends. At the same time, the synthesis of 2004 is scrutinized to capture aspects that may still have been left without being addressed. Finally, an opportunity is provided for updating the database of international APT facilities with respect to the new international APT programs that were initiated since the 2011 synthesis.

In order to investigate the actual behavior evolution of asphalt pavement after the Ultra Violet irradiation (UV-irradiation) aging, reduced-scale accelerated pavement tests were conducted on two separate asphalt mixtures with a stone matrix asphalt (SMA-13) structure, respectively, crumb-rubber modified asphalt mixture and its matrix asphalt mixture, at ambient air temperature. In each group, UV-irradiation aged asphalt mixture after ultraviolet irradiation of 300 h and its corresponding non-aged asphalt mixture were trafficked at the same time by the 1/3 model mobile load simulator (MMLS3) till the cumulative loading applications up to 500,000. The test results show that the performance attenuation degree of the crumb-rubber modified asphalt mixture was lower than that of the matrix asphalt mixture, so the rubber additive helps to reduce the effect of the UV-irradiation aging. Rutting deformation, three-dimensional dynamic strain and seismic modulus were measured during the accelerated loading test. The rutting results (including the rutting depth, rutting area and its development rates), the surface dynamic strains, and the decay rate of the seismic modulus from the UV-irradiation aged asphalt mixture were greater than those of non-aged sample, and the difference narrowed after the cumulative loading applications reached more than 100,000. In addition the analysis of the modification rutting factor from the dynamic shear rheometer (DSR) test, the UV-irradiation aging weakened the high temperature stability and mechanical strength. Therefore, the UV-irradiation aging aggregated the performance decay of asphalt mixture and will inevitably shorten its service life.

Background and Objectives The human leucocyte antigen (HLA) B27 is the most frequently typed single antigen that is associated with diseases. Here, we describe a simple and rapid particle agglutination assay (PaGIA) for HLA-B27 typing. Materials and Methods Superparamagnetic particles were coated with a monoclonal antibody to HLA-B27 and subsequently used for testing. Anticoagulated whole-blood samples were obtained from healthy blood donors (n = 194) with known HLA patterns and from patients (n = 51) who had been typed positive for HLA-B27 by flow cytometry. Results The particles agglutinated only after incubation with HLA-27-positive blood samples, using the ID-microtyping system. Positive reactions were clearly distinguishable from negative reactions in all samples tested. Flow cytometric HLA-B27 typing revealed an indeterminate result in one patient. Conclusions The new HLA-B27 PaGIA is suitable for rapid typing of HLA-B27. The assay is simple and easy to perform, and can be implemented in any routine laboratory.

Projected changes in surface climate are reviewed at a range of temporal scales, with an emphasis on tropical northern Africa—a region considered to be particularly vulnerable to climate change. Noting the key aspects of ‘weather’ affecting crop yield, we then consider relevant and projected change using output from a range of state of the art global climate models (GCMs), and for different future emission scenarios. The outputs from the models reveal significant inter-model variation in the change expected by the end of the twenty-first century for even the lowest IPCC emission scenario. We provide a set of recommendations on future model diagnostics, configurations and ease of use to close further the gap between GCMs and smaller-scale crop models. This has the potential to empower countries to make their own assessments of vulnerability to climate change induced periods of food scarcity.

Stripping of HMA with moisture susceptible aggregates, under high temperature and aircraft loading has been a persistent problem in some areas of the Logan International Airport in Boston, Massachusetts. These problem mixes generally meet the retained tensile strength criteria, after freeze–thaw conditioning. This study was conducted to evaluate the use of accelerated loading equipment for identifying moisture susceptible mixes, and also to evaluate the effect of lime. Mixes with three different aggregates were prepared with PG 76-28 asphalt binder according to specifications. Specimens were conditioned by three different methods: (1) multiple cycles of freeze–thaw, (2) wet trafficking with the model mobile load simulator (MMLS3) and (3) cycles of stress with the moisture induced stress tester, (MIST). Thereafter, the respective indirect tensile strengths were determined. The results showed that accelerated loading can provide useful information for evaluating resistance of HMA to moisture damage under tr...

In this study, a model hot mix asphalt (HMA) pavement was constructed in the laboratory and tested under repeated wheel load applications using Model Mobile Load Simulator 3 (MMLS3). This study presents a discussion on the background of MMLS3, production of test slabs, use of various strain gauges, loading, data acquisition using strain gauges in various directions and analysis of test results. Analysis of data showed the effect of wheel load on fatigue performance of the pavement in terms of strain history and cracking. Different phases of strain history have been identified and their role on fatigue performance discussed. A rational approach of calculation of strain corresponding to failure load applications has also been presented. A finite element model of MMLS3 pavement showed the usefulness of numerical solutions over closed form solutions with respect to effects of boundary conditions. The finite element model presented in this paper successfully described the behavior of the pavement loaded with t...

To alleviate the adverse effects (grittiness and high crumb firmness) caused by the inclusion of sorghum flour in composite breads, sorghum grain was malted with the aim of decreasing the gelatinization temperature and increasing the water-holding capacity of sorghum flour. Four different heat treatments were investigated: drying the malt at high temperatures (50–150°C), stewing, steaming, and boiling before drying the malt at 80°C. Malting decreased the pasting temperature of sorghum to values approaching those of wheat flour, but the paste viscosity was very low. Increasing the malt drying temperature inactivated the amylases but gave malts of darker color and bitter taste. Stewing, steaming, and boiling the malt before drying almost completely inactivated the amylases and increased the enzyme-susceptible starch content and the paste viscosity of malt flours. Bread made with boiled malt flour (30%) had an improved crumb structure, crumb softness, water-holding capacity, and resistance to stalin...

A new accelerated pavement testing (APT) tool has recently been developed between relatively inexpensive laboratory testing and expensive but more realistic full-scale accelerated load testing. The one-third scale model mobile load simulator (MMLS3) applies a scaled load on a single tire smaller than a standard truck tire used in full-scale devices and can be used for both laboratory and field applications. For two hypothetical and eight actual pavement structures at a location where both full-scale APT devices and the MMLS3 were used, stress analyses were conducted to: (1) explore the hypothesis of comparable stress distribution; and (2) compare theoretical and measured rutting performance toward validating a performance prediction methodology. For the hypothetical pavement structures, the comparable stress hypothesis was upheld. Theoretically calculated rutting ratios based on stress analyses after correcting for differences in loading and environmental conditions were compared with actual measured field rutting ratios. The results were credible and demonstrated that when all influencing factors are taken into account, rutting performance under full-scale loading can be predicted based on MMLS3 results and stress analysis.

One-third-scale model mobile load simulator (MMLS3) testing was conducted at the National Center for Asphalt Technology test track. Dry and wet-heated MMLS3 tests were done on five sections. The rutting performances of the sections under MMLS3 trafficking were compared with that under full-scale truck trafficking (truck test sections). A synthesis of the research included evaluation of results from laboratory tests done on cores taken from the MMLS3 test sections within and outside trafficked wheelpaths. Tests on the cores included wet and dry Hamburg wheel tracking, Superpave® shear tester frequency sweep, and semicircular bending (SCB) strength testing. Investigations included the evaluation of full-scale rutting data, laboratory wheel-tracking test results, and climatic data monitored on the track during full-scale truck trafficking. The project validated the rut prediction approach developed to compare MMLS3 and full-scale rutting performance and indicated that the MMLS3 may be used to estimate full-scale rutting at the track under specific conditions. Distress due to wet trafficking was also quantified as reduction in tensile strength as measured by the SCB. Conclusions were drawn and recommendations made for MMLS3 as well as continued full-scale testing at the track. Comparative full-scale rutting performance of the track sections evaluated may be quantified and ranked by the MMLS3 performance of these sections.

Century-long observed gridded land precipitation datasets are a cornerstone of hydrometeorological research. But recent work has suggested that observed Northern Hemisphere midlatitude (NHML) land mean precipitation does not show evidence of an expected negative response to mid-twentieth-century aerosol forcing. Utilizing observed river discharges, the observed runoff is calculated and compared with observed land precipitation. The results show a near-zero twentieth-century trend in observed NHML land mean runoff, in contrast to the significant positive trend in observed NHML land mean precipitation. However, precipitation and runoff share common interannual and decadal variability. An obvious split, or breakpoint, is found in the NHML land mean runoff–precipitation relationship in the 1930s. Using runoff simulated by six land surface models (LSMs), which are driven by the observed precipitation dataset, such breakpoints are absent. These findings support previous hypotheses that inhomogeneities exist in the early-twentieth-century NHML land mean precipitation record. Adjusting the observed precipitation record according to the observed runoff record largely accounts for the departure of the observed precipitation response from that predicted given the real-world aerosol forcing estimate, more than halving the discrepancy from about 6 to around 2 W m−2. Consideration of complementary observed runoff adds support to the suggestion that NHML-wide early-twentieth-century precipitation observations are unsuitable for climate change studies. The agreement between precipitation and runoff over Europe, however, is excellent, supporting the use of whole-twentieth-century observed precipitation datasets here.

The presence of secondary metabolites and of chromium element in seven medicinal plants empirically used for their hypoglycemic action by a phytochemical screening and a qualitative method and other one that is quantitative by Atomic Absorptioli. Spectroscopy for detelmining trivalent chromium has been researched. The studied species are: Phyllantus niruri L. (Chancapiedra), Geranium dielsianum Knut (Pasuchaca), GentianeIla alborosea G. (Hercampure), Otholobium pubescells (Culén), Smallantus sonchifolia (Yacón), Chloraphora tincoria (Mora) y Taraxacum officinalis W (Diente de león). It was phytochemically determined the presence of the following secondary metabolites: alkaloids, flavonoids , tannins, saponins and glycosides, by means of color and precipitation reagents. The determination of chromium element was carried out by qualitative and quantitative via. The accomplished study concludes that, the chemical components determined in the studied species, have a meaning ful importance that can have relationship with their empirical usage of hypoglycemic action., Se ha investigado la presencia de metabolitos secundarios y del elemento cromo en siete plantas medicinales utilizadas empíricamente por su acción hipoglicemiante por medio de una marcha fitoquimica y un método cualitativo y otro cuantitativo por Espectroscopia de Absorción Atómica para la determinación del cromo trivalente. Las especies estudiadas son: Phyllantus niruri L. (Chancapiedra), Geranium dielsianum Knut (pasuchaca), Gentianella alborosea G. (Hercampure), Otholobium pubescens (Culén), Smallantus sonchifolia (Yacón), Chloraphora tincoría (Mora) y Taraxacum officinalis W (Diente de león). Fitoquímicamente se determinó la presencia de los siguientes metabolitos secundarios: alcaloides, flavonoides, taninos, saponinas, y glicósidos, a través de reactivos de coloración y precipitación. La determinación del elemento cromo se hizo por vía cualitativa y cuantitativa El estudio realizado concluye en que los componentes químicos determinados en las especies estudiadas, son de importancia significativa que pueden tener implicancia en su uso empírico de acción hipoglicemiante .

Understanding how precipitation varies as the climate changes is essential to determining the true impact of global warming. This is a difficult task not only due to the large internal variability observed in precipitation but also because of a limited historical record and large biases in simulations of precipitation by general circulation models (GCMs). Here we make use of a technique that spatially and seasonally transforms GCM fields to reduce location biases and investigate the potential of this bias correction to study historical changes. We use two versions of this bias correction - one that conserves intensities and another that conserves integrated precipitation over transformed areas. Focussing on multimodel ensemble means, we find that both versions reduce RMS error in the historical trend by approximately 11% relative to the Global Precipitation Climatology Project (GPCP) data set. By regressing GCMs' historical simulations of precipitation onto radiative forcings, we decompose these simulations into anthropogenic and natural time series. We then perform a simple detection and attribution study to investigate the impact of reducing location biases on detectability. A multiple ordinary least squares regression of GPCP onto the anthropogenic and natural time series, with the assumptions made, finds anthropogenic detectability only when spatial corrections are applied. The result is the same regardless of which form of conservation is used and without reducing the dimensionality of the fields beyond taking zonal means. While "detectability" is dependent both on the exact methodology and the confidence required, this nevertheless demonstrates the potential benefits of correcting location biases in GCMs when studying historical precipitation, especially in cases where a signal was previously undetectable.

The main objective of the most recent Mobile Load Simulator (MLS) test program was to conduct a comparative study of two rehabilitation processes, Rehabs A and B, constructed on the south- and northbound lanes of US281 near Jacksboro, Tex., in 1995 and 1996, respectively. The underlying pavements have composite asphalt layers with the first construction done in 1957. Performance was evaluated in terms of surface rutting, loss of stiffness in pavement layers, and permanent deformation in the layers. Tools used during the study included an on-site weather station, nondestructive testing equipment (FWD, SPA, PSPA, SASW), and in situ instrumentation (MDD). The findings of this study provided conclusive results on the relative performance of the two rehab strategies. Rehab A performed well with its sound underlying structure. The Dallas District has elected to use this recycling process based, in part, on the results of the MLS tests in Jacksboro. The study serves as an example of how the MLS program has yield...

Since the introduction of Crede's prophylaxis the incidence of neonatal ophthalmia has been reduced dramatically. Because of eye irritation the administration of silver nitrate solution was replaced in many countries by antibiotics, e. g. tetracyclin or erythromycin. In Germany, eye prophylaxis is recommended, but can be carried out only with the parent's consent which is often refused. We report on a newborn infant with neonatal ophthalmia. After a poorly monitored pregnancy Crede's prophylaxis was declined after birth by the mother and both mother and child left the hospital four hours after delivery. Two days later the neonate presented with swollen eyelids, hyperemia and purulent discharge; a bacteriological swab was obtained by a pediatrician and an erythromycin ointment was immediately administered locally. The microbiological culture revealed a multidrug-resistant strain of N. gonorrhoeae. Socio-economic circumstances delayed the mandatory systemic therapy with a cephalosporin. Ophthalmological examination one week after treatment showed a cure without consequences. There has been a resurgence of gonorrhea and other sexually transmitted diseases worldwide. Therefore, more attention should be focused on ocular prophylaxis, especially for pregnant women with a low socio-economic status and inadequate prenatal care. Both silver nitrate solution and antibiotics have disadvantages. Povidone-iodine seems to be a promising alternative for the prevention of neonatal ophthalmia, without the risk of inducing adverse effects or drug resistance.

This paper presents the results of a study conducted to explore the use of small-scale models of accelerated pavement testing devices to evaluate the performance of pavements in conjunction with full-scale tests. The motivation for the study was the availability of a model mobile load simulator (MMLS), which had been built originally to illustrate the operation of the full-scale mobile load simulator under design at the time. The scaling requirements will be different depending on whether dynamic (inertia), viscous, or gravity effects are important. One must thus decide which one of these effects controls the behavior to try to reproduce it exactly. In the preliminary tests conducted with the MMLS, emphasis had been placed in reproducing accurately the viscoelastic behavior of the asphalt layer. The possibility of obtaining valid results, even if similitude is not maintained in relation to inertia forces, is explored in this paper. The effects of load frequency or velocity and the effects of layer thicknesses are studied. The total thickness of the model pavement, which must be finite, and its effects on displacements and strains are also considered. It is concluded that even when full similitude is not satisfied, it is possible to obtain valid results that can be extrapolated to predict prototype performance if one were interested primarily in the behavior of the asphalt layer. Preliminary analyses should be conducted, however, to guide on the selection of the model dimensions.

The Texas mobile load simulator (TxMLS) is a newly developed accelerated pavement testing device used to evaluate pavement performance under real trafficking loads. This evaluation is performed by applying trafficking loads and monitoring surface distress, such as cracking and rutting, in conjunction with a number of other measurements of the pavement, such as those conducted with the falling weight deflectometer, multidepth deflectometer, strain gauge, pressure cells, and seismic (stress-wave) tests. A procedure for monitoring the progressive degradation of the asphalt surface was developed using the spectral-analysis-of-surface-waves (SASW) technique. This procedure was applied with the TxMLS and proved to be equally effective. SASW tests that were performed intermittently between trafficking phases on trafficked and untrafficked areas show ( a) the effect of temperatures and frequencies on the asphalt moduli, ( b) the importance of temperature and frequency corrections in analyzing the degradation of the asphalt surface layer, and ( c) the long-term trends in surface-wave velocities (and hence, moduli) of the surface layer with increasing number of load applications. It was found that stiffness of the asphalt layer in the longitudinal direction was progressively reduced under trafficking. Concurrently, surface cracking progressively increased. The reduction in longitudinal stiffness occurred at a faster rate than the crack growth. In contrast, the reduction in the stiffness of the asphalt layer in the transverse direction was slower, probably because the main mode of cracking was transverse. The feasibility of using SASW testing as a predictor of degradation and imminent cracking was confirmed with these studies.

Objetivo: Determinar si la suplementación temprana de hierro disminuye la necesidad, el número y volúmen de glóbulos rojos transfundidos, en relación a la suplementación tardía de hierro en niños con peso de nacimiento menor a 1.301 g. Pacientes y Método: Recién nacidos de muy bajo peso (RNMPN) fueron randomi-zados a recibir suplementación temprana de hierro de 3 mg/kg/día, tan pronto estaban tolerando alimentación enteral de 100 ml/kg/día, o a los 61 días de vida como suplementación tardía. Se midió niveles de hemoglobina al inicio de la suplementación temprana de hierro y a los 2 meses de vida. La transfusión de glóbulos rojos fue restringida de acuerdo a las guías de transfusión y no se administró eritropoyetina. Resultados: No hay diferencias en el número de transfusiones de glóbulos rojos entre los grupos y en relación a las morbilidades asociadas con la prematuridad no habría diferencias significativas. Conclusiones: La suplementación temprana de hierro cuando el niño este tolerando 100 ml/kg/día de leche, no disminuiría la incidencia de las transfusiones de glóbulos rojos en relación al inicio tardío de hierro a los 61 días de vida y probablemente sea segura en los niños menores de 1.301 g. Objective: Determine whether early iron supplementation would decrease the need, the number and volume of transfused red blood cells in relation to late iron supplementation in children with birth weight less than 1,301 g. Patients and Methods: Very low birth weight (VLBW) infants were randomly assigned to receive early iron supplementation of 3 mg/kg/day as soon as they could tolerate enteral feeding of 100 ml/kg/day, or at 61 days of life as late supplementation. Hemoglobin levels were measured at the beginning of early iron supplementation and at 2 months of age. The red blood cell transfusion was performed according to transfusion guidelines and erythropoietin was not administered. Results: No differences were observed regarding the number of red cell transfusions between the groups. Morbidities associated with prematurity presented no significant differences. Conclusions: Early iron supplementation to a child that is tolerating 100 mL/kg/day of milk, does not decrease the incidence of red blood cell transfusions compared to late start iron at 61 days of life, and it is probably safe in infants with birth weight < 1,301 g.

Objective: The complement system has been suggested to play a role in reperfusion injury which may result from an enhanced destruction of myocardial tissue or from an impairment of reflow. We investigated the influence of the C5b-9 complement complex on infarct size, reflow and arrhythmogenesis. Methods: Twenty-eight C6-competent rabbits and 18 rabbits with congenital C6 deficiency were subjected to either 30 min or 2 h of coronary artery occlusion followed by reperfusion. C6 deficiency was confirmed by the complement titration test and immunohistology. The triphenyl tetrazolium chloride method was used to delineate infarct size. Reflow into infarcted areas was evaluated histologically after an in vivo injection of propidium iodide which served as an early fluorescence microscopic marker of damaged myocardium subjected to reflow. Continuous ECG monitoring allowed the recording of arrhythmias. Results: After 30 min of coronary artery occlusion infarct size was significantly smaller in C6-deficient rabbits (5.0 ± 2% of the risk region) as compared to C6-competent rabbits (28.4 ± 8.5%, P = 0.0371). The extent of reflow into damaged myocardium was nearly the same in both animal groups at this time (38 ± 9 vs. 39 ± 7% of the risk region). After 2 h of coronary artery occlusion, infarct size was not different between both animal groups, but the extent of reflow into damaged myocardium was significantly smaller in C6-competent rabbits than in C6-deficient rabbits (25 ± 4 vs. 40 ± 4%; P = 0.0185). Two of the 18 C6-deficient rabbits had ventricular arrhythmias (Lown II–IV), none of which was fatal. Eleven of the 28 C6-competent animals had major ventricular arrhythmmias which were fatal in 6 rabbits. Conclusions: These results suggest that the lytic C5b-9 complement complex leads to reperfusion injury in the early phase (30 min) of ischaemia, resulting in a larger infarct. After 2 h of ischaemia, complement activation enhances the no-reflow phenomenon but does not affect infarct size. Finally, the C6 status seems to influence the susceptibility to ventricular arrhythmias after coronary artery occlusion, independent of reperfusion.

The construction industry of South Africa will be expected to play a key role in the socio-economic development of the country under the new national political dispensation. The industry has an illustrious past and a good regulatory and procedural infrastructure. But the tasks it will face will be different from its past workload in terms of volume, variety and location. This paper is based on discussions which took place at the South African Construction Management Programme (CMP) in June–July 1993. These discussions are supplemented with proceedings from other CMPs, and updated and extended from a literature survey considering mainly recent developments. Present strengths and weaknesses of the construction industry of South Africa are discussed, and the nature of the projects it will be required to undertake examined. A strategic plan for preparing the industry to meet its future tasks is outlined.

Isoelectric focusing of MCF-7 cell extracts revealed an association of the glycolytic enzymes glyceraldehyde 3-phosphate-dehydrogenase, phosphoglycerate kinase, enolase, and pyruvate kinase. This complex between the glycolytic enzymes is sensitive to RNase. p36 could not be detected within this association of glycolytic enzymes; however an association of p36 with a specific form of malate dehydrogenase was found. In MCF-7 cells three forms of malate dehydrogenase can be detected by isoelectric focusing: the mitochondrial form with an isoelectric point between 8.9 and 9.5, the cytosolic form with pl 5.0, and a p36-associated form with pl 7.8. The mitochondrial form comprises the mature mitochondrial isoenzyme (pl 9.5) and its precursor form (pl 8.9). Refocusing of the pl 7.8 form of malate dehydrogenase also gave rise to the mitochondrial isoenzyme. Thus, the pl 7.8 form of malate dehydrogenase is actually the mitochondrial isoenzyme retained in the cytosol by the association with p36. Addition of fructose 1,6-bisphosphate to the initial focusing column induced a quantitative shift of the pl 7.8 form of malate dehydrogenase to the mitochondrial forms (pl 8.9 and 9.5). In MCF-7 cells p36 is not phosphorylated in tyrosine. Kinetic measurements revealed that the pl 7.8 form of malate dehydrogenase has the lowest affinity for NADH. Compared to both mitochondrial forms the cytosolic isoenzyme has a high capacity when measured in the NAD NADH direction (malate oxaloacetate direction). The association of p36 with the mitochondrial isoenzyme may favor the flow of hydrogen from the cytosol into the mitochondria. Inhibition of cell proliferation by AMP which leads to an inhibition of glycolysis has no effect on complex formation by glycolytic and glutaminolytic enzymes in MCF-7 cells. AMP treatment leads to an activation of malate dehydrogenase, which correlates with the increase of pyruvate and the decrease of lactate levels, but has no effect on the distribution of the various malate dehydrogenase forms. © 1996 Wiley-Liss, Inc.

Review on PKM2 (pyruvate kinase isoenzyme type M2), with data on DNA, on the protein encoded, and where the gene is implicated.

This paper which analyzes the nature of highway construction contract claims, offers specific insights into both the classification and frequency of claims and the fundamental causes of claims. The study analyzed 71 claims for additional compensation processed by a large public transportation agency between 1982 and 1987. It is emphasized that highway agencies should devote greater attention to the root cuases of problems, such as inadequate effort applied to the quality assurance/quality control of engineering, drafting, and specification development efforts. It is pointed out that owners may find it in their best interest to allocate related risks equitably.

En este artículo se resuelve el problema de estimación de estado con presencia de errores de difícil detección usando algoritmos de optimización combinatorial. Se propone un procedimiento que combina la metodología clásica de estimación de estado con la teoría de puntos de apalancamiento, estos últimos se usan como factores de sensibilidad. La teoría de observabilidad se usa para penalizar la infactibilidad en la función objetivo. El modelo resultante se resuelve mediante las técnicas de optimización Búsqueda Tabú, Simulated Annealing, Particle Swarm y Algoritmo Genético Modificado Chu-Beasley. Con el fin de validar la metodología propuesta se utiliza como sistema de prueba el IEEE de 57 nodos. Los resultados obtenidos son de excelente calidad. In this paper the state estimation problem including hard detection errors are solved using combinatorial optimization algorithms. A novel procedure that combines the classic estate estimation methodology with leverage points theory which are used like sensibility factors and the observability theory are used to penalize the infeasibility in the objective function. The resultant model is solved using several optimization techniques like Tabu Search, Simulated Annealing, Particle Swarm, and the modified genetic algorithm of Chu-Beasley. In order to prove the proposed methodology the 57 nodes IEEE test system is used. The results obtained presents excellent quality.

La fecundación in vitro (FIV) es en la actualidad una biotecnología de rutina en gran número de laboratorios de investigación a escala mundial, utilizada como herramienta para el estudio de diversos aspectos relacionados con la maduración de ovocitos, la fecundación y el desarrollo temprano del embrión en condiciones in vitro. La L-cisteína es un sustrato externo requerido para la síntesis del glutation en la maduración de ovocitos bovinos. Con el objetivo de evaluar el efecto de la suplementación con L-cisteína sobre la maduración in vitro de ovocitos bovinos, se llevó a cabo un experimento con ovarios obtenidos de vacas mestizas beneficiadas en una sala de matanza local. Se utilizaron tres tratamientos con diferentes concentraciones T1: 0 mM; T2: 0,1 mM y T3: 1,0 mM. Aproximadamente 400 Complejos Cumulus Ovocito (COCs) por tratamiento se maduraron en pozos de 500 µL del medio de maduración (TCM-199), distribuyéndose 50 COC por pozo en una incubadora a 5% de CO2, a 38,5°C y con humedad saturada. Los datos se analizaron por medio de un análisis de varianza (ANAVAR). No se observaron diferencias significativas entre los tratamientos en el porcentaje de ovocitos que llegaron a Metafase II (MII, T1: 72,77%, T2: 67,47% y T3: 70,43%). Los resultados indican que la suplementación con L-cisteína durante la maduración no ejerció un efecto sobre el porcentaje de ovocitos bovinos que alcanzaron el estado de MII, sin embargo se deben realizar otras investigaciones para determinar el efecto ulterior que tiene la L-cisteína adicionada en la maduración sobre la fecundación y el desarrollo embrionario in vitro. In vitro fertilization (IVF) is now a routine technique in a number of biotechnology research laboratories worldwide. IVF is used as a tool for the study of various aspects related to oocytes maturation, fertilization and early embryo development. L-cysteine constitutes an external substrate required for synthesis of glutathione in the maturation of cattle oocytes. In order to study the effect of L-cysteine supplementation on in vitro maturation of cattle oocytes, ovaries were obtained from crossbred cows culled at a local slaughterhouse. Three different in vitro maturation treatments were utilized. Each treatment had a different concentrations of L-cysteine: T1: 0 mM, T2: 0.1 mM and T3: 1.0 mM. Approximately 400 Cumulus Oocyte Complexes (COCs) were matured in wells of 500 ìL of maturation medium (TCM-199), with 5% CO at 38.5°C and saturated relative humidity. Data were analyzed using analysis of variance (ANOVA). There were no significant differences between treatments in term of oocytes that arrived to Metafase II (MII, T1: 72.77%, T2: 67.47% and T3: 70.43%). Results indicate that supplementation with L-cysteine during maturation did not possitively affect the percentage of bovine oocytes that reached the M II state. Nonetheless further research should be carried out to determine the effect of L-cysteine supplementation during maturation, on fertilization and on embryonic development in vitro 268-273 hernandezad@unesur.edu.ve hugo.hernandez@fcv.luz.edu.ve Bimestral

MCF-7 human breast cancer cells propagated in vitro were treated with adenosine derivatives added to the culture medium. The effects on cell proliferation, glycolysis, and glutaminolysis were investigated. Of all adenosine derivatives tested, AMP was the most efficient inhibitor of cell proliferation. In AMP-treated cells, DNA synthesis decreased, whereas RNA and protein syntheses rose normally with time. In terms of carbohydrate metabolism, lactate production from glucose was drastically reduced; therefore, most of lactate produced must have been derived from glutamine. Increase in the enzyme activities involved in glutatmate degradation and in the malate-aspartate shuttle were observed. In contrast, actual glycolytic flux rates declined, whereas key glycolytic enzyme activities increased. Metabolites such as fructose 1,6-bisphosphate and pyruvate accumulated in AMP-arrested cells. Based on the lowered NAD level in the AMP-treated cells, lactate dehydrogenase, but not malate dehydrogenase, was impaired; thereby the whole of glycolysis was inhibited. In compensation, glutamine catabolism was increased. NAD concentrations fell drastically because of the known inhibition of P-ribose-PP synthesis through heightened intracellular AMP levels. A hypothetical metabolic scheme to explain these results and to show how extracellular AMP may influence carbohydrate metabolism and cell proliferation is presented. © 1992 Wiley-Liss, Inc.

Some types of grain sorghum contain tannins which are deleterious to poultry performance. The quantitative test for sorghum, while useful, cannot feasibly be employed in quality control programs in which quick results are needed at the elevator or feed mill. Two qualitative tests, the “scratch” test and the “bleach” test, are described. These tests will help quality control personnel detect sorghums that contain tannins.

El objetivo de este estudio fue mejorar la producción de embriones bovinos con semen sexado bajo condiciones químicamente definidas mediante la suplementación del medio de fecundación con db-cAMP. Los complejos ovocitos cumulus (COCs) fueron madurados por 18 horas en TCM-199 suplementado y fueron fecundados con espermatozoides X o Y en presencia de heparina (10 g/ml), db-cAMP (1 µM) o sin tratamiento alguno (control). Los presuntivos cigotos fueron cultivados por 54 horas en g-SOF. Desde las 72 a las 144 horas post-inseminación (hpi) los embriones se cultivaron en c-SOF+NEA y desde 144 a 192 hpi fueron colocados en medio de maduración pero sin hormonas. No se observaron diferencias entre tratamientos para los oocitos fecundados con espermatozoides Y cuando se compararon a los controles. Se observó una mejora significativa (P

En el presente estudio se comparó el desempeño de 56 novillas doble propósito que resultaron preñadas luego de la transferencia directa de embriones producidos in vitro cultivados en un medio suplementado con suero o en uno químicamente definido. No se observaron diferencias en las tasas de aborto (30,43% vs. 24,24%), distocias (52,17% vs. 51,52%) y parto normal (17,39% vs. 24,24%) entre las novillas que recibieron embriones cultivados en el medio suplementado con suero y las que recibieron embriones cultivados en el medio químicamente definido. El sexo de la cría afectó significativamente el porcentaje de distocias, 83,33% para machos y 50% para hembras, (P < 0,05). El peso al nacimiento de los becerros tampoco se vio afectado (P > 0,05) por la suplementación sérica durante el cultivo (46,86 ± 2,04 kg, para los becerros derivados de los embriones cultivados en el medio suplementado con suero y 46,28 ± 1,42 kg, para los derivados de los embriones cultivados en el medio químicamente definido) ni por el sexo de la cría (machos, 47,20 ± 1,50 kg y hembras, 45,45 ± 1,84 kg). El peso de los becerros que nacieron muertos o que murieron luego del nacimiento fue significativamente (P < 0,05) mayor (51,92 ± 1,76 kg) al de los becerros que sobrevivieron (43,88 ± 1,22 kg). La sobrevivencia perinatal no se vio afectada ni la suplementación sérica durante el cultivo embrionario, ni por el sexo de los becerros o el nacimiento de un parto distócico. En conclusión, la presencia de suero en el medio de cultivo no afectó el desempeño de las novillas doble propósito que resultaron preñadas luego de la transferencia de embriones producidos in vitro. En este estudio se observó la presencia de becerros con el síndrome del recién nacido gigante evidenciado por un alto peso al nacimiento y una alta tasa de abortos y distocias. In the present study, performance of 56 crossbred dual purpose heifers diagnosed as pregnant after direct transfer of in vitro produced embryos cultured in either media supplemented with serum (n = 23) or in a chemically defined media (n = 33) were compared. No differences were observed in the incidence of abortion (30.34% vs. 24.24%), dystocia (52.17% vs. 51.52%) and normal calving (17.39% vs. 24.24%) in pregnant heifers with embryos produced in either serum supplemented or chemically defined media respectively (P > 0.05). Sex of calves affected significantly the rate of dystocia (males, 83.33% and females, 50%; P < 0.05). The birth weight of calves was not affected (P > 0.05) neither by serum supplementation during in vitro culture (46.86 ± 2.04 kg for calves derived from embryos cultured in the serum supplemented media and 46.28 ± 1.42 kg, for calves derived from embryos cultured in the chemically defined media) nor by sex of calves (males, 47.20 ± 1.50 kg and females, 45.45 ± 1.84 kg). The birth weigh of calves born dead or dying soon after birth was significantly (P < 0.05) higher (51.92 ± 1.76 kg) than that of survivors calves (43.88 ± 1.22 kg). Neither serum supplementation during in vitro culture, sex of calves nor dystocia affected the perinatal survival of calves. In conclusion, the presence of serum during in vitro culture did not affect the reproductive performance of dual purpose pregnant heifers after direct transfer of in vitro produced embryos. Large offspring syndrome (LOS) as observed in this study was evidenced by high birth weigh of calves, high rate of abortions and dystocia. 429 - 436 Bimestral

Se estima que existan un 20% de vacas mestizas doble propósito repetidoras de servicio en la cuenca del Lago de Maracaibo, siendo la consecuencia de este problema el alargamiento del intervalo entre partos lo cual impide que las vacas produzcan una lactancia y un becerro al año. El objetivo de este estudio fue analizar la efectividad del uso de infusiones intrauterinas con Listerine® (alcohol, salicilato, timol y agua) sola o asociada con un progestágeno para el tratamiento de la vaca repetidora de servicio. El ensayo se realizó en una finca comercial ubicada en el municipio Machiques de Perijá del estado Zulia, Venezuela, para lo cual se seleccionaron 85 vacas mestizas repetidoras de servicio, con más de dos servicios fallidos (SF) y un intervalo parto-tratamiento (PT) de 186,9 días. Las vacas fueron asignadas aleatoriamente a tres tratamientos: testigo (T; n=22), sin tratamiento; infusión intrauterina a base de Listerine® (IL; n=42); infusión intrauterina de Listerine® asociada con un progestágeno, (IL+P; n=21). Las variables respuesta estudiadas fueron: tasa de concepción post tratamiento (TC), intervalo tratamiento-preñez (ITP), tasa de eliminación (TE). Los datos fueron analizados a través de procedimientos de frecuencias y la prueba de Ji-cuadrado del paquete estadístico SAS, a excepción del ITP procesado a través del procedimiento GLM del SAS. Los grupos T, IL, ILP tuvieron una tasa de concepción (TC) de 50, 59,5 y 66,6%, respectivamente (P > 0,05). Los ITP fueron T: 49,9 ± 9,8 días; IL: 41,0 ± 6,5 días; ILP: 35,1 ± 8,9 días mientras que la TE mostró valores de 31,8; 19,0 y 14,3% para T, IL y ILP respectivamente (P > 0,05). Las vacas del ensayo presentaron un intervalo parto preñez (IPP) 221,7 ± 75,15 días. El tratamiento con Listerine® solo o asociado con progestágenos no fueron efectivos para mejorar la eficiencia reproductiva de las vacas repetidoras de servicios. In Maracaibo lake basin, around 20% of crossbred dual purpose cows are considered repeat breeders, having long postpartum intervals and impeding the main farm objective of one calf per cow, per year. The aim of this study was to evaluate the effect of the use of an intrauterine infusion with Listerine® alone or associated with progestins for the treatment of repeat breeder cows. The experiment was conducted in a commercial farm located at Machiques, Perijá county, Zulia state, Venezuela. A total of 85 crossbred repeat breeder cows with more than two failure services (FS) and interval from parturition to treatment (PT) of 186.9 days were included in this study. Cows were allotted into three treatments: Control (T, n=22), without treatment; intrauterine infusion of Listerine® (IL; n=42); intrauterine infusion of Listerine® associated with progestins, (IL+P; n=21). The studied variables were: posttreatment conception rate (TC), treatment-conception interval (ITP), culling rate (TE). The statistical analysis was performed through frequency procedures and chi-square method of SAS. The ITP was analyzed by ANOVA using the GLM (General Linear Model). T, IL, IL+P groups had TCP values of 50, 59.5 and 66.6%, respectively (P > 0.05). The ITP were T = 49.9 ± 9.8 days; IL = 41.0 ± 6.5 days; IL+P = 35.1 ± 8.9 days and the TE showed values of 31.8, 19 y 14.3% for T, IL, IL+P, respectively (P > 0.05). Cows in this work had a calving to conception interval (IPP) of 221.7 ± 75.15 days. Neither IL or IL+P could improve the reproductive efficiency of repeat breeder cows in this experiment. 204 - 209 Bimestral

El objetivo de este experimento fue investigar el efecto del Factor de Crecimiento Epidermal (EGF), durante la maduración in vitro (MIV) de oocitos bovinos, sobre el desarrollo embrionario in vitro. Los oocitos fueron obtenidos por aspiración de ovarios provenientes de vacas de matadero. Se seleccionaron 163 complejos oocitos-cumulus (COC´s), con tres o más capas de células de la granulosa y fueron incubados durante 24 horas en medios de maduración ovocitaria (OMM) químicamente definidos, con los siguientes tratamientos: 1) OMM modificado (T1); 2) OMM modificado suplementado con 10 ng/ml de EGF (T2); 3) OMM modificado suplementado con suero fetal bovino al 10% (T3). Luego de la MIV, en cada medio, los oocitos fueron incubados con espermatozoides (2 x 10^6/ml), durante 18 horas. Los oocitos fecundados fueron denudados y cultivados in vitro hasta el estadio de blastocistos. Los oocitos madurados en T2 y T3, presentaron una tasa de división similar, pero significativamente mayor que los madurados en T1 (P

Con el objeto de determinar el efecto de la suplementación postparto con bloques multinutricionales sobre el reinicio de la actividad ovárica postparto en vacas mestizas de doble propósito, se realizó un ensayo en la Hacienda San Pedro, Municipio Machiques de Perijá. Edo. Zulia, Venezuela. Se utilizaron 20 vacas primíparas y 38 vacas de dos y más partos, las cuales se asignaron aleatoriamente a dos tratamientos (T1: pastoreo rotacional más 1.0 kg de alimento concentrado en cada ordeño, el cual se realizó sin apoyo del becerro, T2: Pastoreo rotacional más 0.5 kg de alimento concentrado y suplementación con los bloques multinutricionales). Las variables en estudio fueron: reinicio de la actividad ovárica, intervalo a la primera descarga de progesterona (P4) postparto, intervalo parto-primer celo, producción de leche a los 100 días postparto, condición corporal al celo. Como variables discretas se utilizaron el efecto de la suplementación con bloques multinutricionales (con bloques, sin bloques), el número de partos (1 parto, 2 ó más partos), época de parto (seca, lluviosa). Los datos fueron analizados a través de un modelo de varianza-covarianza usando el paquete estadístico SAS. El grupo T2 mostró significativamente (P< 0.01) una mayor frecuencia de reinicio de actividad ovárica con respecto al grupo T1 (82.76% vs 37.48%), los intervalos a la primera descarga de P4 y al primer celo fueron significativamente menores, en las vacas del T2 que las vacas del T1. No se observó efecto significativo de la suplementación con bloques sobre la producción de leche, y la condición corporal al primer celo. Las vacas que parieron durante la época lluviosa produjeron más leche (P< 0.05) que las que lo hicieron durante la época seca. Los resultados obtenidos en este ensayo demuestran que los bloques multinutricionales pueden ser usados como una alternativa alimenticia para mejorar el comportamiento reproductivo de las vacas mestizas doble propósito en el trópico. In order to determine a possible supplementation effect multinutritional blocks on reinitiation ovarian activity in dual purpose crossbred cows postpartum, an assay was conducted at San Pedro farm located in Machiques, Zulia state, Venezuela. Twenty primiparous cows and thirty eighth of two and over calving cows were randomly assigned to 2 treatments (T1: rotational grazing + 1 kg commercial concentrate per milking; T2: rotational grazing + 0.5 kg commercial concentrate + blocks supplementation). Data involving reinitiation ovarian activity, first progesterone discharge (P4), calving heat interval (CHI), 100 days milk yield and body condition were analyzed using model including fixed effects by T1 and T2, number of calving (1 or 2 and over) and season (dry, rainy. T2 was highly significant on reinitiation of ovarian activity as compared to T1 cows (82.7 vs 37.5%, respectively; P< 0.01). Both P4 and CHI from T2 cows were quite smaller (P< 0.05) than T1 cows. There was no blocks effect either on milk production or body condition at first heat. Cows calving in rainy season produced more milk (P< 0.05) than cows of dry season: Results suggested that multinutritional blocks can be used as a feeding choice for reproduction improvement of dual purpose crossbreed cows in the tropics. 331 - 336 jaaranguren@luz.edu.ve Trimestral