Quantitative analysis and phase assemblage of basic oxygen furnace slag hydration.

Basic oxygen furnace (BOF) slag from steelmaking could be applied as a binder in building materials, reducing the CO2 footprint and solid waste, which is relevant for industrial waste management and circular economy. However, its use is mostly restricted because its hydraulic activity is poorly understood. The BOF slag was hydrated in this study, and its reaction products were systematically characterized using XRD, QXRD, and SEM/EDX-based phase mapping. Internal consistency checks of the data were performed between the analytical techniques. The results revealed that the composition of the amorphous hydration products could be identified and quantified, and the main hydration products were hydrogarnets and C-S-H gel. An extended milling process significantly improved the reactivity, and all the major slag phases, including wüstite, participated in the reaction. Brownmillerite formed hydrogarnets during the first 7 days of hydration. The new hydration products contributed to the immobilization of vanadium and chromium. Particle size played an important role in the amount of C2S reacting, the composition of the hydrogarnets and C-S-H gel, their proportions, and the immobilization capacity. Based on the findings, an overall hydration reaction was developed.

Stimulated two-photon emission in bulk CdSe.

While two-photon emission processes are firmly established in atomic physics, their observation and use in semiconductor physics remains elusive. Here, we experimentally investigate stimulated two-photon emission in photoexcited bulk CdSe and identify requirements for the observation of stimulated two-photon emission. In particular, this process requires population inversion as well as two-photon transition energies close to the bandgap energy. In any regime investigated in the present study, net optical gain is not achieved, as the free-carrier absorption intrinsically linked to the photoexcitation completely masks the two-photon gain. The results are well in line with a recent study on nondegenerate versions of two-photon emission in GaAs and place clear limits for the practical use of two-photon emission in optically excited semiconductors.

Buffer capacity of 4% succinylated gelatin does not provide any advantages over acidic 6% hydroxyethyl starch 130/0.4 for acid-base balance during experimental mixed acidaemia in a porcine model.

BACKGROUND AND OBJECTIVE: Four percent gelatine is an alkaline compound due to NH2 groups, whereas 6% hydroxyethyl starch 130/0.4 (HES130) has acidic features. We investigated whether these solutions lead to differences in acid-base balance in pigs during acidaemia and correction of pH. METHODS: Anaesthetized pigs were randomized to HES130 or gelatine infusion (n = 5 per group). Animals received acid infusion (0.4 M solution of lactic acid and HCl diluted in normal saline) and low tidal volume ventilation (6-7 mL kg(-1), PaCO2 of 80-85 mmHg, pH 7.19-7.24). Measurements were made before and after induction of acidaemia, before and after correction of pH with haemofiltration (continuous venovenous haemofiltration) and tris-hydroxymethylaminomethane infusion. We measured parameters describing acid-base balance according to Stewart's approach, ketone body formation, oxygen delivery, haemodynamics, diuresis and urinary pH. RESULTS: Acid-base balance did not differ significantly between the groups. In HES130-treated pigs, the haemodilution-based drop of haemoglobin (1.4 +/- 1.0 g dL(-1), median +/- SD) was paralleled by an increase in the cardiac output (0.5 +/- 0.4 L min(-1). Lacking increases in cardiac output, gelatine-treated pigs demonstrated a reduction in oxygen delivery (149.4 +/- 106.0 mL min(-1)). Tris-hydroxymethylaminomethane volumes required for pH titration to desired values were significantly higher in the gelatine group (0.7 +/- 0.1 mL kg(-1) h(-1) vs. HES130: 0.5 +/- 0.2 mL kg(-1) h(-1)). CONCLUSION: The buffer capacity of gelatine did not lead to favourable differences in acid-base balance in comparison to HES130.

[Gene TAENIATA is a novel negative regulator of the Arabidopsis thaliana homeobox genes KNAT1, KNAT2, KNAT6, and STM].

Mutant Arabidopsis thaliana taeniata (tae) plants are characterized by an altered morphology of leaves and the inflorescence. At the beginning of flowering, the inflorescence produces fertile flowers morphologically intermediate between a shoot and a flower. The recessive mutation tae also causes the formation of ectopic meristems and shoot rosettes on leaves. The expressivity of the mutant characters depend on the temperature and photoperiod. Analysis of the activity of KNOX class I genes in the leaves of the tae mutant has demonstrated the expression of genes KNAT2 and STM and an increase in the expression of genes KNAT1 and KNAT6 compared to wild-type leaves. These data indicate that the TAE gene negatively regulates the KNAT1, KNAT2, KNAT6, and STM genes.

Effectiveness of a rural pediatric diabetes management program.

BACKGROUND: Children with type 1 diabetes living in rural areas may have limited access to specialty diabetes care compared to children living in urban areas. To address this issue, providers have developed outreach services in which specialists travel periodically to rural communities. OBJECTIVE: To determine whether the care of children with type 1 diabetes treated by pediatric endocrinologists in a rural outpatient clinic is comparable to the care of children treated in an urban medical center by the same diabetes team. METHODS: We carried out a retrospective cohort study comparing the number of patient visits with physicians, behavioral specialists, and dietitians and the frequency of hemoglobin A1c (HbA1c) measurements over a 12-month period treated in a rural clinic with a matched group treated in an urban children's hospital clinic. RESULTS: We found that urban patients (n = 38) were more likely to complete four visits per year compared to a matched group (n = 19) at the rural clinic (55.3% vs. 15.8%; p < 0.004), were significantly more likely than those in the rural clinic to have had four HbA1c measurements per year (55.3% vs. 21.1%; p < 0.014), and more likely to have had an assessment by a behavioral specialist (31.6% vs. 0%). Children at the rural clinic site were more likely to have had a visit with a nutritionist during the year (89.5% vs. 36.8%; p < 0.005). CONCLUSION: We conclude that diabetes care provided using a rural outreach model closely approximates, but does not entirely duplicate, care provided in the urban setting.

Characteristics and financial performance of a pediatric faculty inpatient attending service: a resource-based relative value scale analysis.

OBJECTIVES: In many children's hospitals, inpatient attending physician services are provided by academic faculty who function as part-time inpatient specialists or hospitalists. Although some have claimed that hospitalist care can reduce length of stay and total hospital resource use and expenses, there are few benchmarks or data regarding physician productivity or the characteristics and financial performance of these programs. The resource-based relative value scale (RBRVS) is a valuable tool for developing national benchmarks and comparing the financial performance of inpatient programs at varying daily census and reimbursement levels. The objectives of this study were to 1) describe physician productivity on an inpatient service as measured by total relative value units (TRVUs) and professional charges, 2) determine whether inpatient collections were adequate to support faculty salaries for the time spent attending, and 3) develop a model to evaluate financial performance of inpatient programs at varying census and TRVU reimbursement levels. METHODS: A retrospective review of hospital discharge and faculty practice billing data between June 1997 and July 1998 was conducted in a general medical service in a regional, 208-bed, university-affiliated children's hospital in the Pacific Northwest. RESULTS: Of 4113 patients who were admitted to the children's hospital general medical service during a 12-month period, faculty part-time hospitalists (N = 28) served as the attending physician for 1738 (42%). On an annual basis, faculty attended for an average of 29.1 days (median: 21.0; range: 7.0-97.0), with an average daily patient census (ADC) of 7.2 (median: 6.5; range: 2.8-12.0). Inpatient attendings billed for 1738 initial visits and 3957 subsequent visits. Total physician productivity for the inpatient attending group during 1 year included 12 085 TRVUs and gross professional charges of $777 743. The average payment, or conversion factor (CF), was $24.46/TRVU (71% of Medicare CF). The cash collection rate was 38%, reflecting a payor mix that included 54% Medicaid, 28% commercial payors, 12% health maintenance organization, and 6% other payors. On a weekly basis, physicians generated an average of 109 TRVUs and collected $2665 in cash. The average salary cost per RVU was $23.40, and weekly faculty salary and benefit expenses were $2550. After operating expenses and academic taxes totaling 24% were deducted ($5.87/TRVU), RBRVS-based payments and cash collections covered 79% of average faculty weekly salaries. Financial modeling showed that either an average CF of $31/TRVU or an ADC of 9 patients per day on the inpatient service would be required to generate sufficient revenue to support physician salaries and operating expenses. CONCLUSIONS: For a faculty inpatient attending service in a children's hospital with an ADC of 7, a $24.46 RBRVS-based CF payment is inadequate to support faculty salaries and operating expenses for the time spent attending. Inpatient services in similar payor environments with comparable expenses and staffed by faculty who care for fewer than 9 patients per day will not cover typical faculty salary costs and operating expenses.

A MADS domain gene involved in the transition to flowering in Arabidopsis.

Flowering time in many plants is triggered by environmental factors that lead to uniform flowering in plant populations, ensuring higher reproductive success. So far, several genes have been identified that are involved in flowering time control. AGL20 (AGAMOUS LIKE 20) is a MADS domain gene from Arabidopsis that is activated in shoot apical meristems during the transition to flowering. By transposon tagging we have identified late flowering agl20 mutants, showing that AGL20 is involved in flowering time control. In previously described late flowering mutants of the long-day and constitutive pathways of floral induction the expression of AGL20 is down-regulated, demonstrating that AGL20 acts downstream to the mutated genes. Moreover, we can show that AGL20 is also regulated by the gibberellin (GA) pathway, indicating that AGL20 integrates signals of different pathways of floral induction and might be a central component for the induction of flowering. In addition, the constitutive expression of AGL20 in Arabidopsis is sufficient for photoperiod independent flowering and the over-expression of the orthologous gene from mustard, MADSA, in the classical short-day tobacco Maryland Mammoth bypasses the strict photoperiodic control of flowering.

Cytokinin and gibberellin activate SaMADS A, a gene apparently involved in regulation of the floral transition in Sinapis alba.

In plants of Sinapis alba induced to flower by one long day, the MADS box gene, SaMADS A, is expressed initially in the central corpus (L3 cells) of the shoot apical meristem (SAM), about 1.5-2 days before initiation of the first floral meristem. We have combined a physiological approach by testing the effects of three putative floral signals on SaMADS A expression in the SAM of S. alba plants with a transgenic approach using Arabidopsis thaliana plants. A single application of a low dose of a cytokinin or a gibberellin to the apex of vegetative S. alba plants is capable of mimicking perfectly the initial effect of the long day on SaMADS A transcription. A treatment combining the two hormones causes the same activation but seems to enhance the level of SaMADS A expression. A sucrose application to the apex of vegetative plants is, on the contrary, unable to activate SaMADS A expression. None of these chemicals, alone or combined, is capable of causing the floral shift at the SAM. Since the constitutive expression of SaMADS A leads to precocious flowering in A. thaliana and antisense expression of a fragment of the A. thaliana homologue AGL20 leads to a delay in flowering time, these results are consistent with SaMADS A activation being an intermediate event in a cytokinin- and/or gibberellin-triggered signal transduction pathway that is involved in the regulation of floral transition in S. alba.

Computerized pediatric telephone triage and advice programs at children's hospitals: operating and financial characteristics.

OBJECTIVE: To describe the operating characteristics, financial performance, and perceived value of computerized children's hospital-based telephone triage and advice (TTA) programs. DESIGN: A written survey of all 32 children's hospital-based TTA programs in the United States that used the same proprietary pediatric TTA software product for at least 6 months. MAIN OUTCOME MEASURES: The expense, revenues, and perceived value of children's hospital-based TTA programs. RESULTS: Of 30 programs (94%) responding, 27 (90%) were eligible for the study and reported on their experience with nearly 1.3 million TTA calls over a 12-month period. Programs provided pediatric TTA services for 1560 physicians, serving an average of 82 physicians (range, 10-340 physicians) and answering 38880 calls (range, 8500-140000 calls) annually. The mean call duration was 11.3 minutes and the estimated mean total expense per call was $12.45. Of programs charging fees for TTA services, 16 (59%) used a per-call fee and 7 (26%) used a monthly service fee. All respondents indicated that fees did not cover all associated costs. Telephone triage and advice programs, when examined on a stand-alone basis, were all operating with annual deficits (mean, $447000; median, $325000; range, $74000-$1.3 million), supported by the sponsoring children's hospitals and their companion programs. Using a 3-point Likert scale, the TTA program managers rated the value of the TTA program very highly as a mechanism for marketing to physicians (2.85) and increasing physician (2.92) and patient (2.80) satisfaction. CONCLUSIONS: Children's hospital-based TTA programs operate at substantial financial deficits. Ongoing support of these programs may derive from the perception that they are a valuable mechanism for marketing and increase patient and physician satisfaction. Children's hospitals should develop strategies to ensure the long-term financial viability of TTA programs or they may have to discontinue these services.

FPF1 modulates the competence to flowering in Arabidopsis.

During the transition to flowing the FPF1 gene is expressed in the peripheral zone of apical meristems and in floral meristems of Arabidopsis. Constitutive expression of FPF1 causes early flowering in Arabidopsis under both long-day and short-day conditions and leads to a shortened juvenile phase as measured by the trichome distribution on the abaxial leaf surface. In the classical late flowering mutants, overexpression of FPF1 compensates partially for the late flowering phenotype, indicating that FPF1 acts downstream or in a parallel pathway to the mutated genes. The co-overexpression of 35S::AP1 with 35S::FPF1 leads to a synergistic effect on the shortening of the time to flowering under short-day conditions. The co-overexpression of 35S::FPF1 and 35S::LFY, however, shows only an additive reduction of flowering time and the conversion of nearly every shoot meristem, except the inflorescence meristem, to a floral meristem under the same light conditions. In addition, the constitutive expression of FPF1 attenuates the severe lfy-1 phenotype under short days and phenocopies to a great extent the lfy-1 mutant grown under long-day conditions. Thus, we assume that FPF1 modulates the competence to flowering of apical meristems.

FPF1 promotes flowering in Arabidopsis.

We have characterized the gene flowering promoting factor1 (FPF1), which is expressed in apical meristems immediately after the photoperiodic induction of flowering in the long-day plants mustard and Arabidopsis. In early transition stages, expression is only detectable in the peripheral zone of apical meristems; however, later on, it can also be found in floral meristems and in axillary meristems that form secondary inflorescences. The FPF1 gene encodes a 12.6-kD protein that has no homology to any previously identified protein of known function. Constitutive expression of the gene in Arabidopsis under control of the cauliflower mosaic virus 35S promoter resulted in a dominant heritable trait of early flowering under both short- and long-day conditions. Treatments with gibberellin (GA) and paclobutrazol, a GA biosynthesis inhibitor, as well as crosses with GA-deficient mutants indicate that FPF1 is involved in a GA-dependent signaling pathway and modulates a GA response in apical meristems during the transition to flowering.

Hospital services for rural children in Washington State.

OBJECTIVE: To examine the current delivery of inpatient hospital services to a statewide population of rural children, define the types of pediatric conditions currently treated in rural hospitals or transferred to urban centers, and explore the role of rural pediatricians and family practitioners in the care of children in rural hospitals. DESIGN: Retrospective review of statewide hospital discharge data. SUBJECTS: All patients younger than 18 years of age with nonsurgical diagnoses discharged from both urban and rural civilian hospitals in Washington State during 1989 and 1990. RESULTS: Of 69690 pediatric hospital discharges during the study period, 16% were rural residents and 10% were from rural hospitals. Rural hospitals cared for 59% of hospitalized rural children. Marked differences were found between urban and rural hospitals in the diagnoses treated; more than two-thirds of all discharges for chemotherapy, psychiatric disorders, and neonates with multiple major problems were from urban hospitals; but the majority of the discharges for gastrointestinal diagnoses, respiratory conditions, or minor problems in the neonatal period were from rural hospitals. Rural hospitals with staff pediatricians had higher annual pediatric discharges, total charges, lengths of stay, and case mix with a higher proportion of neonates with complications, compared to hospitals without pediatricians. However, there was no evidence that these hospitals served as local referral centers for rural pediatric inpatients; the proportion of patients from outside the local hospital catchment areas was similar for rural hospitals with staff pediatricians and for those without. In rural hospitals, pediatricians and family practitioners were listed as the attending physician for 37% and 49% of discharges, respectively. The average rural pediatrician cared for five times as many inpatients as a rural family practitioner. Pediatricians cared for significantly more neonates with birth weights of less than 2500 grams, but otherwise had a similar case mix among inpatient discharges as rural family practitioners. CONCLUSIONS: Most rural children in Washington who require hospitalization for common problems receive their care in local rural hospitals staffed with pediatricians and family practitioners, although those with illnesses requiring a high level of specialty care are predominantly cared for in urban centers. Rural pediatricians make a substantial contribution to the care of rural children, especially in the area of neonatal care, although their presence in rural hospitals does not in itself create local referral centers. Inpatient volumes are higher for pediatricians, but their case mix is similar to that of rural family practitioners, except in the area of neonatology. These data support the recommendations that family practitioners contemplating rural practice receive training in general inpatient pediatrics (regardless of whether they are going to a site with pediatricians) and that pediatricians in rural practice be trained for a high volume of inpatient cases, including problems of low birth weight infants. Because systems of hospital care for rural children depend on regionalized programs, clinical and educational linkages between urban centers and rural providers should be developed and supported.

Identification of two MADS box genes that are expressed in the apical meristem of the long-day plant Sinapis alba in transition to flowering.

To understand the molecular mechanisms involved in the transition from vegetative to reproductive growth, the photoperiodic-controlled induction of flowering in the long-day plant Sinapis alba was used to screen for regulatory genes which are expressed upon induction in the apical meristem. By using the conserved MADS box-encoding region of the organ identity gene AGAMOUS, the genes SaMADS A and SaMADS B were identified which are expressed in transition stages of mustard. RNA blot analysis has confirmed that the transcript levels of both genes are drastically increased shortly after the induction of flowering and that both genes are expressed earlier than the known MADS box genes. In situ hybridization studies have shown that the expression of the genes is restricted to the apical meristem of induced plants during early phases of reproductive development. The expression of SaMADS A is first detectable in the central zone of the meristem, a region where the earliest changes of an evoked meristem could be detected by classical physiological methods, suggesting that SaMADS A may have an important function during the transition to flowering.

Physician experience with pediatric inpatient care in Washington State.

OBJECTIVE: To determine the frequency with which pediatricians and family physicians in Washington State serve as attending physicians for pediatric inpatients. DESIGN: Retrospective review of statewide hospital discharge data. SUBJECTS: Attending physicians for all patients younger than 18 years of age with nonsurgical diagnoses discharged from civilian hospitals in Washington State during 1989 and 1990. RESULTS: Using medical rosters, the self-identified specialty of the attending physician was determined for 93% (n = 181,581) of discharges. Pediatricians and family physicians were listed as attending for 61% and 28%, respectively, of all eligible patients. Statewide, 97% (n = 555) of all pediatricians and 86% (n = 939) of all family physicians served as attending physicians for at least one inpatient, including healthy newborns, during the 2-year study period. The median annual number of discharges per physician was 78 for pediatricians and 14.5 for family physicians. Excluding healthy newborns, the median annual number of discharges was 25 for pediatricians and 3 for family physicians. Five percent of the physician attending group provided inpatient care for 50% of all children hospitalized with diagnoses other than healthy newborn; 50% of attending physicians cared for 95% of the patients. In rural hospitals, where family physicians served as attending physicians for 44% of pediatric inpatients, children were 3.3 times more likely to receive their care from family physicians than those hospitalized in urban centers. CONCLUSIONS: Most pediatricians and family physicians serve as inpatient attending physicians for hospitalized children only infrequently. These findings question whether the emphasis on inpatient care in many pediatric and family medicine training programs remains an appropriate goal.

Circadian oscillations of a transcript encoding a germin-like protein that is associated with cell walls in young leaves of the long-day plant Sinapis alba L.

As part of an attempt to analyze rhythmic phenomena in the long-day plant Sinapis alba L. at the molecular level, we have searched for mRNAs whose concentration varies as a function of time of day. Differential screening of a cDNA library established from mRNAs expressed at the end of the daily light phase with probes representing transcripts expressed predominantly in the morning or evening has identified one major transcript. The cDNA, Saglp, encodes a predicted 22-kD protein with an N-terminal signal sequence. The protein shows homology to germin, a protein expressed in wheat embryos after onset of germination. The Saglp mRNA level undergoes circadian oscillations in light/dark cycles with maxima between 8 and 12 PM (zeitgeber time [zt]12-zt16) and minima around 8 PM (zt0). In plants grown from seed in constant light, transcript levels are constitutive. In constant light regular temperature shifts function as an alternative "zeitgeber" to initiate Saglp transcript oscillations. At the cellular level, Saglp transcripts are expressed in the epidermis and spongy parenchyma of young leaves, and in distinct regions of the epidermis and the cortex in stems and petioles. Strong signals are observed in these tissues around zt12, whereas little expression is found around zt20, suggesting that the underlying oscillatory mechanism(s) operate(s) synchronously in different plant organs. The SaGLP steady-state protein concentration remains constant over light/dark cycles. Immunogold labeling shows that the SaGLP protein is associated with primary cell walls.

A light- and temperature-entrained circadian clock controls expression of transcripts encoding nuclear proteins with homology to RNA-binding proteins in meristematic tissue.

To investigate physiological processes generated by endogenous circadian rhythms on the molecular level, we have identified clock-controlled genes in the long-day plant Sinapis alba L. A cDNA library was differentially screened using cDNA probes representing transcripts expressed at either the middle of the light period or the middle of the dark period. Two closely related groups of transcripts, Sagrp1 and Sagrp2, controlled by a circadian rhythm have been isolated. RNA blot analysis verified that transcript levels oscillate in plants grown in light/dark cycles with maxima between 'Zeitgeber' time (zt)8 and zt12 (8-12 h after onset of illumination) and minima around zt20. Steady-state mRNA levels continue to oscillate in plants shifted from light/dark cycles to constant light. No synchronous mRNA oscillations are found in plants grown from seed in constant light at constant temperature, suggesting that the clock has to be entrained initially. In contrast, when plants grown in constant light are exposed to rhythmic temperature shifts oscillations of steady-state Sagrp mRNA levels are induced, indicating that temperature acts as an alternative external stimulus (zeitgeber) other than light to entrain the oscillator. In situ hybridization reveals that both transcript groups are expressed predominantly in meristematic and growing tissue. Strong expression is observed in the leaf primordia of the shoot apex, the procambial strands, cambium and in all cell layers of young leaves around zt12. In contrast, little or no signal is found on tissue sections isolated at zt20. This indicates that the oscillator(s) regulating Sagrp transcript fluctuations operate(s) synchronously in different organs. For both transcript groups cDNAs were isolated corresponding to unspliced pre-mRNAs or to transcripts generated by the use of a second 5' splice site. The cDNAs corresponding to the fully spliced transcripts contain open reading frames for polypeptides of 16 kDa, each containing a putative N-terminal RNA recognition motif and a C-terminal region rich in glycine. The predicted proteins show strong homology to an ABA-inducible glycine-rich protein from maize embryos and to the mammalian RNA-binding protein A1 of the heterogeneous nuclear ribonucleoprotein complex involved in pre-mRNA splicing. The SaGRP protein fluctuates with a very low amplitude over light/dark cycles. Immunogold labeling demonstrates the presence of the SaGRP protein within the nucleus of the investigated meristematic cells of young leaves.