Vocabulary knowledge and reading comprehension account for SES-differences in how school-aged children infer word meanings from sentences

Socioeconomic status (SES)-related language gaps are known to widen throughout the course of the school years; however, not all children from lower SES homes perform worse than their higher SES peers on measures of language. The current study uses mediation and moderated mediation to examine how cognitive and language abilities (vocabulary, reading, phonological processing, working memory) account for individual differences in a children's ability to infer a novel word's meaning, a key component in word learning, in school-aged children from varying SES backgrounds. Vocabulary and reading comprehension mediated the relationship between SES and accuracy when inferring word meanings. The relationship between SES, vocabulary, and inferring word meaning was moderated by age, such that the influence of vocabulary on task performance was strongest in young children. The reading pathway did not interact with age effects, indicating reading is an important contributor to SES-related differences in how children infer a word's meaning throughout grade school. These findings highlight different paths by which children's trajectories for inferring word meanings may be impacted.

Comparative study on La-promoted Ni/γ-Al2O3 for methane dry reforming – spray drying for enhanced nickel dispersion and strong metal–support interactions

Dry reforming of methane (DRM) enables an efficient utilization of two abundant greenhouse gases by converting them into syngas, a versatile feedstock for chemical synthesis. Aiming for high catalyst performance and enhanced coke resistance, different preparation techniques of La-promoted Ni/γ-Al₂O₃ catalysts for DRM were compared facilitating structure–performance correlations. The studied synthesis techniques comprehend incipient wetness impregnation and co-precipitation as well as alternative techniques such as spray drying. All catalysts were fully characterized before and after reaction by N₂-physisorption, XRD, H₂-TPR and STEM-EDX elemental mapping. Additionally, a thorough investigation of carbon deposits has been carried out by TGA/DSC and STEM-EDX, respectively. The different preparation techniques led generally to very different physical properties, structure, chemical species and anti-coking properties of the catalyst. However, some catalysts with similar physicochemical characteristics differed in catalytic performance and coking resistance. Superior catalytic performance could be reached for catalysts prepared by spray drying and related to excellent Ni dispersion, strong metal–support interaction and very low coke formation of only 2.7% of the catalyst weight. After 6 h time on stream only minor sintering occurred, with few Ni nanoparticles up to 10 nm.

Clear structure-performance correlation for the dry reforming of methane – spray drying for excellent sintering and cocking resistivity.

Female fecundity and offspring survival are not increased through sexual cannibalism in the spider Larinioides sclopetarius

Many hypotheses explaining the evolution and maintenance of sexual cannibalism incorporate the nutritional aspect of the consumption of males. Most studies have focused on a fecundity advantage through consumption of a male; however, recent studies have raised the intriguing possibility that consumption of a male may also affect offspring quality. In particular, recent studies suggest prolonged survival for offspring from sexually cannibalistic females. Here, we measured the protein and lipid content of males compared to insect prey (crickets), quantified female nutrient intake of both prey types and finally assessed how sexual cannibalism affects female fecundity and spiderling quality in the orb-web spider Larinioides sclopetarius. We found no evidence that sexual cannibalism increased fecundity when compared to a female control group fed a cricket. Contrary to previous studies, spiderlings from females fed a male showed reduced survival under food deprivation compared to spiderlings from the control group. Offspring from females fed a male also tended to begin web construction sooner. The low lipid content of males compared to crickets may have reduced offspring survival duration. Whether additional proteins obtained through consumption of a male translate to enhanced silk production in offspring requires further investigation.

Nanometre-scale 3D defects in Cr2AlC thin films

MAX-phase Cr₂AlC containing thin films were synthesized by magnetron sputtering in an industrial system. Nanometre-scale 3D defects are observed near the boundary between regions of Cr₂AlC and of the disordered solid solution (CrAl)_xC_y. Shrinkage of the Cr-Cr interplanar distance and elongation of the Cr-Al distance in the vicinity of the defects are detected using transmission electron microscopy. The here observed deformation surrounding the defects was described using density functional theory by comparing the DOS of bulk Cr₂AlC with the DOS of a strained and unstrained Cr₂AlC(0001) surface. From the partial density of states analysis, it can be learned that Cr-C bonds are stronger than Cr-Al bonds in bulk Cr₂AlC. Upon Cr₂AlC(0001) surface formation, both bonds are weakened. While the Cr-C bonds recover their bulk strength as Cr₂AlC(0001) is strained, the Cr-Al bonds experience only a partial recovery, still being weaker than their bulk counterparts. Hence, the strain induced bond strengthening in Cr₂AlC(0001) is larger for Cr d – C p bonds than for Cr d – Al p bonds. The here observed changes in bonding due to the formation of a strained surface are consistent with the experimentally observed elongation of the Cr-Al distance in the vicinity of nm-scale 3D defects in Cr₂AlC thin films.

Elastic properties of fcc Fe-Mn-X (X = Cr, Co, Ni, Cu) alloys studied by the combinatorial thin film approach and ab initio calculations

The elastic properties of fcc Fe-Mn-X (X = Cr, Co, Ni, Cu) alloys with additions of up to 8 at.% X were studied by combinatorial thin film growth and characterization and by ab initio calculations using the disordered local moments (DLM) approach. The lattice parameter and Young's modulus values change only marginally with X. The calculations and experiments are in good agreement. We demonstrate that the elastic properties of transition metal alloyed Fe-Mn can be predicted by the DLM model.

Ab initio study of the effect of Si on the phase stability and electronic structure of γ- and α-Al2O3

Using density functional theory, the effect of Si on the stability and electronic structure of γ- and α-Al2O3 has been investigated. The concentration range from 0 to 5 at.% is probed and the additive is positioned at different substitutional sites in the γ-phase. The calculations for (Al,Si)2O3 predict a trend towards spontaneous decomposition into α-/γ-Al2O3 and SiO2. Therefore, the formation of the metastable γ-(Al,Si)2O3 phase can only be expected during non-equilibrium processing where the decomposition is kinetically hindered. The Si-induced changes in stability of this metastable solid solution may be understood based on the electronic structure. As the Si concentration is increased, stiff silicon-oxygen bonds are formed giving rise to the observed stabilization of the γ-phase.

Systematic study on the electronic structure and mechanical properties of X2BC (X = Mo, Ti, V, Zr, Nb, Hf, Ta and W)

In this work the electronic structure and mechanical properties of the phases X(2)BC with X =Ti, V, Zr, Nb, Mo, Hf, Ta, W (Mo(2)BC-prototype) were studied using ab initio calculations. As the valence electron concentration (VEC) per atom is increased by substitution of the transition metal X, the six very strong bonds between the transition metal and the carbon shift to lower energies relative to the Fermi level, thereby increasing the bulk modulus to values of up to 350 GPa, which corresponds to 93% of the value reported for c-BN. Systems with higher VEC appear to be ductile as inferred from both the more positive Cauchy pressure and the larger value of the bulk to shear modulus ratio (B/G). The more ductile behavior is a result of the more delocalized interatomic interactions due to larger orbital overlap in smaller unit cells. The calculated phase stabilities show an increasing trend as the VEC is decreased. This rather unusual combination of high stiffness and moderate ductility renders X(2)BC compounds with X = Ta, Mo and W as promising candidates for protection of cutting and forming tools.

Quantum mechanically guided design of Co43Fe20Ta(5.5)X(31.5) (X=B, Si, P, S) metallic glasses

A systematic ab initio molecular dynamics study was carried out to identify valence electron concentration and size induced changes on structure, elastic and magnetic properties for Co(43)Fe(20)Ta(5.5)X(31.5) (X=B, Si, P, S). Short range order, charge transfer and the bonding nature are analyzed by means of density of states, Bader decomposition and pair distribution function analysis. A clear trend of a decrease in density and bulk modulus as well as a weaker cohesion was observed as the valence electron concentration is increased by replacing B with Si and further with P and S. These changes may be understood based on increased interatomic distances, variations in coordination numbers and the electronic structure changes; as the valence electron concentration of X is increased the X bonding becomes more ionic, which disrupts the overall metallic interactions, leading to lower cohesion and stiffness. The highest magnetic moments for the transition metals are identified for X=S, despite the fact that the presence of X generally reduces the magnetic moment of Co. Furthermore, this study reveals an extended diagonal relationship between B and P within these amorphous alloys. Based on quantum mechanical data we identify composition induced changes in short range order, charge transfer and bonding nature and link them to density, elasticity and magnetism. The interplay between transition metal d band filling and s-d hybridization was identified to be a key materials design criterion.

Using the de Haas-van Alphen effect to map out the closed three-dimensional Fermi surface of natural graphite

The Fermi surface of graphite has been mapped out using de Haas-van Alphen (dHvA) measurements at low temperature with in-situ rotation. For tilt angles θ>60° between the magnetic field and the c axis, the majority electron and hole dHvA periods no longer follow a cos(θ) behavior demonstrating that graphite has a three-dimensional closed Fermi surface. The Fermi surface of graphite is accurately described by highly elongated ellipsoids. A comparison with the calculated Fermi surface suggests that the Slonczewski-Weiss-McClure trigonal warping parameter γ(3) is significantly larger than previously thought.

Ab initio molecular dynamics model for density, elastic properties and short range order of Co-Fe-Ta-B metallic glass thin films

Density, elastic modulus and the pair distribution function of Co-Fe-Ta-B metallic glasses were obtained by ab initio molecular dynamics simulations and measured for sputtered thin films using x-ray reflectivity, nanoindentation and x-ray diffraction using high energy photons. The computationally obtained density of 8.19 g cm(-3) for Co(43)Fe(20)Ta(5.5)B(31.5) and 8.42 g cm(-3) for Co(45.5)Fe(24)Ta(6)B(24.5), as well as the Young's moduli of 273 and 251 GPa, respectively, are consistent with our experiments and literature data. These data, together with the good agreement between the theoretical and the experimental pair distribution functions, indicate that the model established here is useful to describe the density, elasticity and short range order of Co-Fe-Ta-B metallic glass thin films. Irrespective of the investigated variation in chemical composition, (Co, Fe)-B cluster formation and Co-Fe interactions are identified by density-of-states analysis. Strong bonds within the structural units and between the metallic species may give rise to the comparatively large stiffness.

The influence of additions of Al and Si on the lattice stability of fcc and hcp Fe-Mn random alloys

We have studied the influence of additions of Al and Si on the lattice stability of face-centred-cubic (fcc) versus hexagonal-closed-packed (hcp) Fe-Mn random alloys, considering the influence of magnetism below and above the fcc Néel temperature. Employing two different ab initio approaches with respect to basis sets and treatment of magnetic and chemical disorder, we are able to quantify the predictive power of the ab initio methods. We find that the addition of Al strongly stabilizes the fcc lattice independent of the regarded magnetic states. For Si a much stronger dependence on magnetism is observed. Compared to Al, almost no volume change is observed as Si is added to Fe-Mn, indicating that the electronic contributions are responsible for stabilization/destabilization of the fcc phase.

Fluorinated Heteroaromatic Polyethers for Low Dielectric Constant/High Temperature Applications

Synthesis and characterization of three classes of poly(arylene ether oxazole)s and poly(arylene ether thiazole)s with trifluoromethyl substituents in various positions is described. Based on these examples, the influence of the chemical structure of the polymers on properties such as glass transition temperature, solubility, and thermal stability will be discussed. Structural parameters studied are the number and nature of the heteroaromatic rings, the number and position of the trifluoromethyl groups, and the structure (flexibility, polarity) of various linking groups.

Ab initio lattice stability of fcc and hcp Fe-Mn random alloys

We have studied the lattice stability of face centred cubic (fcc) versus hexagonal close packed (hcp) Fe-Mn random alloys using ab initio calculations. In the calculations we considered the antiferromagnetic order of local moments, which for fcc alloys models the magnetic configuration of this phase at room temperature (below its Néel temperature) as well as their complete disorder, corresponding to paramagnetic fcc and hcp alloys. For both cases, the results are consistent with our thermodynamic calculations, obtained within the Calphad approach. For the room temperature magnetic configuration, the cross-over of the total energies of the hcp phase and the fcc phase of Fe-Mn alloys is at the expected Mn content, whereas for the magnetic configuration above the fcc Néel temperature, the hcp lattice is more stable within the whole composition range studied. The increase of the total energy difference between hcp and antiferromagnetic fcc due to additions of Mn as well as the stabilizing effect of antiferromagnetic ordering on the fcc phase are well displayed. These results are of relevance for understanding the deformation mechanisms of these random alloys.

Graphite from the viewpoint of Landau level spectroscopy: an effective graphene bilayer and monolayer

We describe an infrared transmission study of a thin layer of bulk graphite in magnetic fields up to B=34 T. Two series of absorption lines whose energy scales as sqrt[B] and B are present in the spectra and identified as contributions of massless holes at the H point and massive electrons in the vicinity of the K point, respectively. We find that the optical response of the K point electrons corresponds, over a wide range of energy and magnetic field, to a graphene bilayer with an effective interlayer coupling 2gamma_{1}, twice the value for a real graphene bilayer, which reflects the crystal ordering of bulk graphite along the c axis. The K point electrons thus behave as massive Dirac fermions with a mass enhanced twice in comparison to a true graphene bilayer.

Consistent interpretation of the low-temperature magnetotransport in graphite using the Slonczewski-Weiss-McClure 3D band-structure calculations

Magnetotransport of natural graphite and highly oriented pyrolytic graphite has been measured at mK temperatures. Quantum oscillations for both electron and hole carriers are observed with an orbital angular momentum quantum number up to N approximately 90. A remarkable agreement is obtained when comparing the data and the predictions of the Slonczewski-Weiss-McClure tight binding model for massive fermions. No evidence for Dirac fermions is observed in the transport data which are dominated by the crossing of the Landau bands at the Fermi level, corresponding to dE/dk_{z}=0, which occurs away from the H point where Dirac fermions are expected.

Optical absorption to probe the quantum Hall ferromagnet at filling factor nu=1

Optical absorption measurements are used to probe the spin polarization in the integer and fractional quantum Hall effect regimes. The system is fully spin polarized only at filling factor nu=1 and at very low temperatures ( approximately 40 mK). A small change in filling factor (deltanu approximately +/-0.01) leads to a significant depolarization. This suggests that the itinerant quantum Hall ferromagnet at nu=1 is surprisingly fragile against increasing temperature, or against small changes in filling factor.

A Bayesian belief network for quality assessment: application to employment officer support

BACKGROUND

'Supported' employment stipulates that disabled people should have real jobs for real pay. This paper models kinds of supported employment, assesses how the support and placement features affect its outcomes and its quality from the perspective of the employees, and provides a dynamic model to help explore what types of interventions might promote greater social inclusion for people with learning and other disabilities.

METHOD

Bayesian belief networks (BBNs) provide the general framework for modelling the relationships between the variables and features of interest. The structure, probabilistic specification and quality indicators were elicited from project advisory groups, including people with learning disability, and took into account a pilot survey of 30 individuals. A subsequent survey of 1,461 supported employees was used to update the model and to provide actual assessments of quality of placement.

RESULTS

We present the BBN methodology in some detail, as novel to this discipline. We show how the model was constructed, and its implications for supported employment. We derive indices for quality of placement, taking into account the views of clients. We show how survey and individual results can be used to update the model. Use of the model suggests that quality of placement is, on average, relatively high, with small differences between groups with differing primary disability.

CONCLUSIONS

The BBN is the appropriate methodology to model complex relationships and interventions for problems such as these. The model developed in this study can be used to assess and improve the fit between people and jobs, both at the individual level and for groups of employees, and can take into account different kinds of quality for different stakeholders.

Combined sagittal and coronal plane postural stability model

We present a preliminary study of combined anterior posterior (AP) and medial lateral (ML) sway assuming a classic inverted pendulum with included subtalar movement. Based on a feedback control posture model in the sagittal plane as presented by Maurer and Peterka, we have investigated parameters needed to model ML sway components. Center of pressure (COP) data was collected from a population of 8 normal adults (age 18 to 30 years) using a dual AMTI force plate system. Fourteen different sway metrics were calculated. The collected data was successfully compared to numerous simulations of the model where model parameters were varied and the goal was to reproduce both AP and ML components.

The asymptotic leading term of anisotropic small-angle scattering intensities. II. Non-convex particles

For anisotropic particulate samples with scattering contrast (delta n)(2), the leading asymptotic term of the scattering intensity, along a direction q (q/q) of reciprocal space, is [4 pi(2)(delta n)(2)/q(4)]sigmaj [1/kappaG.j(+/-q)]. Here, kappaG.j(+/-q)denotes the Gaussian curvature value at the points (labelled by j) of the interphase surface where the normal is either parallel or antiparallel to q. If the Gaussian curvature vanishes at, say, the jth of these points, the corresponding contribution takes the form Cj/qalpha with 2< or = alphaj<4, Cj and alphaj being determined by the local behaviour of the surface. However, the intensity detected by a counter pixel, with opening solid angle deltaomega(q0) along (mean) direction q0, asymptotically still behaves as 4pi(2) (delta n)(2)(deltaomega(q0))/q(4), where S(deltaomega(q0)) is the area of that part of the interface that has its normals inside deltaomega(q0).

Collaboration to implement smoking cessation guidelines during the childbirth continuum

BACKGROUND

Smoking during pregnancy has been linked with such negative outcomes as increased risk for spontaneous abortions, low birth weight, and perinatal and neonatal mortality. In spring 1998 three leading health care systems in San Diego initiated the Trilateral Partnership ("the Partnership"), whose mission is to improve the health and well-being of children. The Partnership chose tobacco control in pregnant women and their families as its first initiative. PROGRAM COMPONENTS-YEAR ONE (1999): Three interventions were developed: intervention by the prenatal care provider, initiation of a referral process to telephone counseling for pregnant women, and intervention for women reporting spontaneously quitting smoking. To date, 83% of the more-than 20,000 women who have been seen in prenatal screening in 28 months counted themselves as nonsmokers. Eleven percent of the women reported they independently stopped smoking once they learned they were pregnant. Six percent reported that they were still smoking. Twenty-three percent of the women reported living in a household with other smokers. PROGRAM COMPONENTS-YEAR TWO (2000): Activity focused on continuing the previous components, hospital intervention for all new mothers at the time of delivery, pediatric intervention at the newborn's visits at 2 and 6 months of age, and development and refinement of a telephone protocol for new parents.

ELEMENTS OF SUCCESS

The noncontroversial topic of encouraging smoking cessation during pregnancy was one that enhanced immediate buy-in by most individuals contacted to support and engage in the program. Strong commitment and financial support from three health care systems opened doors for the Smoke-Free Families staff and increased the program's visibility in the community.

Female control of paternity in the sexually cannibalistic spider Argiope keyserlingi

Sexual conflict theory predicts an antagonistic coevolution, with each sex evolving adaptations and counter-adaptations to overcome a temporary dominance of the other sex over the control of paternity. Polyandry allows sexual selection to operate after mating has commenced, with male and female interests competing for control of fertilization. There are numerous examples of male control of paternity, but few studies have unambiguously revealed female control. Attributing variance in paternity to females is often difficult since male and female influences cannot be separated unambiguously. However, we show that polyandrous female orb-web spiders Argiope keserlingi (Arancidae) control the paternity of their offspring by adjusting the timing of sexual cannibalism. Our experiments reveal that females copulating with relatively smaller males delay sexual cannibalism, thereby prolonging the duration of copulation, and that these males consequently fertilize relatively more eggs.

Chronic disease self-management: improving health outcomes

Chronic disease has become pandemic in the United States, and estimates are that it will affect 148 million people by the year 2030. Patients with chronic illnesses cost the health care system over three times more than individuals without chronic conditions. The US Department of Veterans' Affairs (VA) Sunshine HealthCare Network, composed of VA health care facilities in Florida and Puerto Rico, recognized that the needs of its increasing number of veterans with chronic diseases were unmet by traditional medical interventions. The Network implemented a chronic disease self-management pilot program to evaluate its value for the veteran population. Results of the pilot indicate that this program will make a positive, lasting change in the health status and quality of life for veterans with chronic disease.

[Methodological assessment of nutritional problems as part of a health care initiative for hospitalized children]

A health care initiative has been set up in a French regional hospital to improve the management of children admitted to the pediatric unit. It involves screening these children, aged between 6 months and 5 years, for nutritional problems. Health care professionals are first trained. They then measure and weigh the children according to a predetermined protocol and calculate an indicator (weight/height ratio) using the EPI-INFO computer program. The medical team is notified if a child is found to be over- or underweight and decisions are taken as to whether further investigations will be carried out. The family are interviewed and the child's eating habits are observed. Nutritional advice is given and the child's doctor is informed. This initiative has been planned and analyzed according to recognized good practice in community programs. All the health care professionals involved in the scheme participated during the year of the study. In total, 1,004 children were admitted to the hospital and 964 were included in the study (97. 8%). Of these, 142 children (14.7%) were included after their discharge from the hospital. Sixty-nine children were identified as being over- or underweight, with 25 (2.6%) underweight and 44 (4.6%) overweight. Sixty-five of these children were identified before their discharge from hospital. The notification rate was only 64.5% and the treatment rate was similar. Efficacy was not assessed. This initiative requires the active participation and awareness of the entire health care team. Improvement should be possible with better computer programs, regular data collection and improved efficiency, which is often not the case when dealing with obesity problems.

Infanticide by males in a spider with suicidal maternal care, Stegodyphus lineatus (Eresidae)

Infanticide by males in species with high maternal investment may be the most extreme example of a reproductive conflict of interests between males and females. The subsocial spider Stegodyphus lineatus is semelparous, and the offspring eat their mother. Male and female maturation overlap, such that late maturing males encounter females that are already guarding the single clutch. A late male may try to remove the existing egg sac, thereby forcing the female to replace the clutch and use his sperm to fertilize at least some of the eggs. Males were responsible for 33% of all the egg losses in a population of 278 females with eggs. By losing her clutch, the female loses time equivalent to the age of the lost clutch plus the time it takes to replace it. The earlier in the season a female lost a clutch and the younger the eggs were, the longer was the interval between clutch loss and clutch replacement. Females that lost their egg sacs by infanticide replaced them after a significantly longer time than females that lost their egg sacs from other causes. The time loss of 18.5 days on average corresponds to a 23% reduction in female survival probability. In addition to reduced survival, females suffered a fecundity cost: replacement clutches were smaller than the original clutches and the reduction in egg number was greater with increasing intervals between the first and second clutch. Females defended their egg sacs aggressively against males. In field tests, the outcome of fights between males and females was determined by the relative size difference of the contestants. The mating system of S. lineatus provides an example of a male mating strategy that evolved despite being very costly for the females.

Relative effects of antepartum and intrapartum maternal blood glucose levels on incidence of neonatal hypoglycemia

OBJECTIVE

The objective of this study was to compare the relative effects of both antepartum and intrapartum maternal plasma glucose concentrations on neonatal plasma glucose levels.

STUDY DESIGN

This was a prospective, nonrandomized study. Two hundred thirty-three pregnant insulin-requiring patients with diabetes received intensive diabetic treatment aimed at maintaining the 2-hour postprandial plasma glucose level < 150 mg/dl and the intrapartum plasma glucose level < 100 mg/dl. The neonatal plasma glucose level was monitored during the first 48 hours of life and the incidence of neonatal hypoglycemia was compared with the average antepartum and intrapartum maternal plasma glucose concentrations.

RESULTS

The lowest incidence of neonatal hypoglycemia occurred, as expected, among infants of patients who had the lowest mean antepartum and intrapartum plasma glucose levels. However, the intrapartum plasma glucose concentration had a stronger association with decreased neonatal hypoglycemia than the antepartum plasma glucose levels.

CONCLUSIONS

Even in the presence of poor antepartum diabetic control tight regulation of the intrapartum plasma glucose levels will significantly reduce the incidence of neonatal hypoglycemia.

Pregnancies in a patient with congenital absence of prothrombin activity: case report

Congenital hypoprothrombinemias are very rare, inherited disorders in which factor II (prothrombin) levels and/or activity are extremely low or absent. We report eight pregnancies in a patient with this disorder. Obstetric complications attributed to the coagulation disturbance included first-trimester bleeding in each pregnancy, miscarriage in four of the pregnancies, spontaneous maternal subarachnoid hemorrhage in one, and postpartum hemorrhage in one of four term pregnancies despite administration of clotting factor concentrate. The management of pregnancy in congenital hypoprothrombinemia, and issues of coagulation factor replacement, are discussed.

Severe preeclampsia with fulminant and extreme elevation of aspartate aminotransferase and lactate dehydrogenase levels: high risk for maternal death

We report a subgroup of patients with fulminant hemolysis, elevated liver enzymes, low platelet count (HELLP) syndrome, manifesting extreme elevation of aspartate aminotransferase (AST; SGOT) and lactate dehydrogenase (LDH) levels and abnormal mental status. These gravidas are at high risk for mortality. Only four patients treated by the authors over a 10-year period have had AST more than 2000 IU/L and LDH more than 3000 IU/L in the HELLP syndrome. This report is based on retrospective chart review. All patients manifested disordered mental status, jaundice, intense hemolysis, and extreme hypertension. One patient had developed multiple organ system failure, was moribund at initial perinatal consultation, and died. The three others were treated with aggressive afterload reduction and plasma infusion or plasmapheresis; two survived. Fulminant HELLP syndrome occurs rarely, but marks a group of patients at high risk for mortality. Optimal therapy is unclear; early intervention, including afterload reduction, volume expansion, and consideration of plasma infusions or plasmapheresis, is recommended.

Management of virtual private networks for integrated broadband communication

Management of Virtual Private Networks (VPNs) is becoming an increasingly important issue in the context of integrated broadband communication (IBC). In the near future corporate customers may want to subscribe to broadband VPN services offered by globally operating service providers to replace most of their leased line services that are used today to build their corporate networks. The concepts historically known as characterizing VPNs, such as the concept of closed user groups, will still be valid, but the importance of VPN service features and, in particular, the set of VPN management services offered to VPN customers will become dominant. In this paper we present a detailed technical approach to the management of broadband VPNs based on current technology and common standards. In particular, we discuss architectural solutions, management interfaces and management services provided at these interfaces, as well as managed objects.

[Passive smoking in children. Its detection by the assay of urinary cotinine]

BACKGROUND

Passive tobacco smoking is responsible for increased respiratory morbidity in young children. This point is not always understood by parents and the use of a sensitive marker for nicotine exposure may help them to smoke less.

POPULATION AND METHODS

Urinary cotinine concentration was measured in 72 children, aged from 1 to 5 years, that had been admitted to our unit during October and November 1991 for various causes. The results were correlated with the smoking habits of their parents. Urine samples were obtained during the first hours after admission and the cotinine concentration was measured by HPLC. Concentrations > 5 micrograms per liter were considered to be positive.

RESULTS

A total of 67 urine samples were analysed: 43 (64.2%) were positive with cotinine concentrations of 5 to 77 micrograms/l (mean: 19.7). Both parents of 21 children were smokers; the fathers of 18 children and the mothers of 11 children, alone, smoked. There was therefore at least one smoker in the environment of 50 children. There was a highly positive correlation between parental smoking and urinary cotinine (p < 0.0001). For the infants with only one parent who was a smoker, their urinary cotinine was higher when the smoker was the mother rather than the father.

CONCLUSIONS

An urinary cotinine of > 6 micrograms per liter is a precise, sensitive, test for passive smoking in young children. This test is well accepted by families and its result may persuade parents to stop or moderate their use of tobacco. This test also could be used, as part of a pulmonary check-up, as a public health indicator.

Binding of bepridil to isolated rat heart mitochondria

We investigated mass action of isolated rat heart mitochondria with the calcium antagonist bepridil. At pH 7.20 bepridil in basic form b associates rapidly with the mitochondrial membrane but the amount fixed is higher in non-energized mitochondria than in mitochondria energized by succinate or ATP Mg2+. This effect is related to the dissociation state of the drug since conditions favoring the acidic form bH+ suppress this difference. Tritiated bepridil bound to mitochondrial membrane is only partially displaced by high concentrations of unlabeled drug (greater than or equal to 510(-5) M). No membrane energization effect is noted on this displacement. Binding values of bepridil to mitochondrial membrane (KD 1.710(-5) M; Bmax 23.8 nmol.mg-1 protein) show only low affinity receptor sites. Bepridil binding to the lipid part of the inner membrane surface is postulated. This interaction is used to explain some of the in vitro effects of this calcium antagonist on membrane bound enzyme activities.

Effects of bepridil on calcium release from rat heart mitochondria

Bepridil at concentrations above 10 microM, and at pH 7.2 stimulates calcium release from rat heart mitochondria. However this action is different from that of ClCCP, an uncoupler of oxidative phosphorylations, since it is ruthenium red insensitive. At lower concentrations bepridil may inhibit the Na-induced calcium release. The effects of bepridil depend on the pH and indicate that the protonated form of the drug is more efficient on calcium release than the basic form.

Redistribution of creatine kinase isoenzymes in chronically overloaded myocardium

Chronic overload due to an experimental abdominal aortic stenosis in rats causes hypertrophy of ventricles and a parallel increase of the MB and BB isoforms of creatine kinase (CK) in cardiac tissue. The CK isoenzyme profile was determined using a new two-step method combining anion exchange chromatography and electrophoresis. In overloaded ventricles a shift was observed from the MM isoform which decreased (from 407 +/- 10 mumol X min-1 X g-1 ww in sham-operated to 370 +/- 0.13, in the overloaded group, p less than 0.05) towards the MB and BB forms whose activity was enhanced (from 56 +/- 4 and 6.5 +/- 0.7 to 77 +/- 6 and 10.1 +/- 1.2, respectively, p less than 0.02). These modifications were more pronounced (318 +/- 15, 83 +/- 15 and 15.1 +/- 2.5, for the MM, MB and BB forms respectively, p less than 0.01) in rats having a very marked hypertrophy and whose ventricular/body weight ratio (expressed in mg of ventricles per g) was above 3. Moreover this ratio correlates both with the amount of the MB form (r = 0.32, p less than 0.05) and with the percentage of the B monomer (r = 0.51, p less than 0.01). This shift, like that previously described for lactate dehydrogenase and myosin, favoured the fetal form and this supports the hypothesis that overloaded myocytes improve their efficiency by expressing some of the isoforms normally present in the fetus.