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Scientific exploration of phototrophic bacteria over nearly 200 years has revealed large phylogenetic gaps between known phototrophic groups that limit understanding of how phototrophy evolved and diversified1,2. Here, through Boreal Shield lake water incubations, we cultivated an anoxygenic phototrophic bacterium from a previously unknown order within the Chloroflexota phylum that represents a highly novel transition form in the evolution of photosynthesis. Unlike all other known phototrophs, this bacterium uses a type I reaction centre (RCI) for light energy conversion yet belongs to the same bacterial phylum as organisms that use a type II reaction centre (RCII) for phototrophy. Using physiological, phylogenomic and environmental metatranscriptomic data, we demonstrate active RCI-utilizing metabolism by the strain alongside usage of chlorosomes3and bacteriochlorophylls4related to those of RCII-utilizing Chloroflexota members. Despite using different reaction centres, our phylogenomic data provide strong evidence that RCI-utilizing and RCII-utilizing Chloroflexia members inherited phototrophy from a most recent common phototrophic ancestor. The Chloroflexota phylum preserves an evolutionary record of the use of contrasting phototrophic modes among genetically related bacteria, giving new context for exploring the diversification of phototrophy on Earth.

Organ transplantation from ABOblood group–incompatible (ABOi) donors requires accurate detection, effective removal and subsequent surveillance of antidonor antibodies. Because ABHantigen subtypes are expressed differently in various cells and organs, measurement of antibodies specific for the antigen subtypes in the graft is essential. Erythrocyte agglutination, the century‐old assay used clinically, does not discriminate subtype‐specific ABOantibodies and provides limited information on antibody isotypes. We designed and created an ABO‐glycan microarray and demonstrated the precise assessment of both the presence and, importantly, the absence of donor‐specific antibodies in an international study of pediatric heart transplant patients. Specific IgM, IgG, and IgA isotype antibodies to nonself ABHsubtypes were detected in control participants and recipients of ABO‐compatible transplants. Conversely, in children who received ABOi transplants, antibodies specific for A subtype IIand/or B subtype IIantigens—the only ABHantigen subtypes expressed in heart tissue—were absent, demonstrating the fine specificity of B cell tolerance to donor/graft blood group antigens. In contrast to the hemagglutination assay, the ABO‐glycan microarray allows detailed characterization of donor‐specific antibodies necessary for effective transplant management, representing a major step forward in precise ABOantibody detection. The authors design a novel ABH‐glycan microarray and demonstrate its effectiveness and accuracy in confirming donor‐specific B cell tolerance in a cohort of ABO‐incompatible pediatric heart transplant patients.

Organ transplantation from ABO blood group–incompatible (ABOi) donors requires accurate detection, effective removal and subsequent surveillance of antidonor antibodies. Because ABH antigen subtypes are expressed differently in various cells and organs, measurement of antibodies specific for the antigen subtypes in the graft is essential. Erythrocyte agglutination, the century-old assay used clinically, does not discriminate subtype-specific ABO antibodies and provides limited information on antibody isotypes. We designed and created an ABO-glycan microarray and demonstrated the precise assessment of both the presence and, importantly, the absence of donor-specific antibodies in an international study of pediatric heart transplant patients. Specific IgM, IgG, and IgA isotype antibodies to nonself ABH subtypes were detected in control participants and recipients of ABO-compatible transplants. Conversely, in children who received ABOi transplants, antibodies specific for A subtype II and/or B subtype II antigens—the only ABH antigen subtypes expressed in heart tissue—were absent, demonstrating the fine specificity of B cell tolerance to donor/graft blood group antigens. In contrast to the hemagglutination assay, the ABO-glycan microarray allows detailed characterization of donor-specific antibodies necessary for effective transplant management, representing a major step forward in precise ABO antibody detection.

Blood group ABH(O) carbohydrate antigens are carried by precursor structures denoted type I–IV chains, creating unique antigen epitopes that may differ in expression between circulating erythrocytes and vascular endothelial cells. Characterization of such differences is invaluable in many clinical settings including transplantation. Monoclonal antibodies were generated and epitope specificities were characterized against chemically synthesized type I–IV ABH and related glycans. Antigen expression was detected on endomyocardial biopsies (n = 50) and spleen (n = 11) by immunohistochemical staining and on erythrocytes by flow cytometry. On vascular endothelial cells of heart and spleen, only type II–based ABH antigens were expressed; type III/IV structures were not detected. Type II–based ABH were expressed on erythrocytes of all blood groups. Group A1and A2erythrocytes additionally expressed type III/IV precursors, whereas group B and O erythrocytes did not. Intensity of A/B antigen expression differed among group A1, A2, A1B, A2B and B erythrocytes. On group A2erythrocytes, type III H structures were largely un-glycosylated with the terminal “A” sugar α-GalNAc. Together, these studies define qualitative and quantitative differences in ABH antigen expression between erythrocytes and vascular tissues. These expression profiles have important implications that must be considered in clinical settings of ABO-incompatible transplantation when interpreting anti-ABO antibodies measured by hemagglutination assays with reagent erythrocytes.

Blood group ABH(O) carbohydrate antigens are carried by precursor structures denoted type I–IV chains, creating unique antigen epitopes that may differ in expression between circulating erythrocytes and vascular endothelial cells. Characterization of such differences is invaluable in many clinical settings including transplantation. Monoclonal antibodies were generated and epitope specificities were characterized against chemically synthesized type I–IV ABH and related glycans. Antigen expression was detected on endomyocardial biopsies (n = 50) and spleen (n = 11) by immunohistochemical staining and on erythrocytes by flow cytometry. On vascular endothelial cells of heart and spleen, only type II–based ABH antigens were expressed; type III/IV structures were not detected. Type II–based ABH were expressed on erythrocytes of all blood groups. Group A1and A2erythrocytes additionally expressed type III/IV precursors, whereas group B and O erythrocytes did not. Intensity of A/B antigen expression differed among group A1, A2, A1B, A2B and B erythrocytes. On group A2erythrocytes, type III H structures were largely un‐glycosylated with the terminal “A” sugar α‐GalNAc. Together, these studies define qualitative and quantitative differences in ABH antigen expression between erythrocytes and vascular tissues. These expression profiles have important implications that must be considered in clinical settings of ABO‐incompatible transplantation when interpreting anti‐ABO antibodies measured by hemagglutination assays with reagent erythrocytes. ABO(H) blood group antigens are composed of distinct subtype chains that are differentially expressed by erythrocytes used to detect ABO antibodies and cells of transplanted organs, raising important implications regarding interpretation of isohemagglutinin titers for determining suitability for ABO‐incompatible organ transplantation and posttransplant management.

Context:Serum estradiol (E2) levels are preserved in older reproductive-aged women with regular menstrual cycles despite declining ovarian function.Objective:The objective of the study was to determine whether increased granulosa cell aromatase expression and activity account for preservation of E2 levels in older, regularly cycling women.Design:The protocol included daily blood sampling and dominant follicle aspirations at an academic medical center during a natural menstrual cycle.Subjects:Healthy, regularly cycling older (36–45 y; n = 13) and younger (22–34 y; n = 14) women participated in the study.Main Outcome Measures:Hormone levels were measured in peripheral blood and follicular fluid aspirates and granulosa cell CYP19A1(aromatase) and FSH-RmRNA expression were determined.Results:Older women had higher FSH levels than younger women during the early follicular phase with similar E2 but lower inhibin B and antimullerian hormone levels. Late follicular phase serum E2 did not differ between the two groups. Follicular fluid E2 [older (O) = 960.0 [interquartile range (IQR) 765.0–1419.0]; younger (Y) = 994.5 [647.3–1426.5] ng/mL, P= 1.0], estrone (O = 39.6 [29.5–54.1]; Y = 28.8 [22.5–42.1] ng/mL, P= 0.3), and the E2 to testosterone (T) ratio (O = 109.0 ± 41.9; Y = 83.0 ± 18.6, P= .50) were preserved in older women. Granulosa cell CYP19A1expression was increased 3-fold in older compared with younger women (P< .001), with no difference in FSH-Rexpression.Conclusions:Ovarian aromatase expression increases with age in regularly cycling women. Thus, up-regulation of aromatase activity appears to compensate for the known age-related decrease in granulosa cell number in the dominant follicle to maintain ovarian estrogen production in older premenopausal women.

We aimed to compare children started on twice daily injections (BD) versus multiple daily injections (MDI) from diagnosis, using HbA1cand weight gain as outcome measures.

Although ABO blood group incompatible cardiac transplantation in neonates and infants reduces waiting list mortality without compromising outcome, the technique has not been adopted by all centers, and to date Toronto remains the only center to have published results from a large case series. We present a review of ABO-incompatible heart transplantation in the United Kingdom (UK) where current recipient selection criteria differ somewhat from those used in the United States (US) and Canada. Between February 2000 and November 2006, 21 ABO-incompatible cardiac transplants were performed in children aged 2-40 months (median 10.0). Immunosuppression followed standard regimens. Pretransplant donor-specific isohemagglutinins of >1:4, (the UNOS cutoff), were present in five patients and reduced by plasma exchange. After transplantation, 1921 recipients demonstrated persisting deficiency of donor-specific isohemagglutinins. Significant donor-specific isohemagglutinins levels were detected repeatedly in 221 recipients who have shown no clinical or biopsy evidence of rejection. All recipients survive without retransplantation and there have been no episodes of humoral rejection. We conclude it is possible for other centers to replicate the excellent results achieved in Toronto and that ABO-incompatible transplantation may be performed successfully in some patients beyond infancy with established isohemagglutinin production providing preoperative antibody removing strategies are used.

Although ABO blood group incompatible cardiac transplantation in neonates and infants reduces waiting list mortality without compromising outcome, the technique has not been adopted by all centers, and to date Toronto remains the only center to have published results from a large case series. We present a review of ABO-incompatible heart transplantation in the United Kingdom (UK) where current recipient selection criteria differ somewhat from those used in the United States (US) and Canada. Between February 2000 and November 2006, 21 ABO-incompatible cardiac transplants were performed in children aged 2–40 months (median 10.0). Immunosuppression followed standard regimens. Pretransplant donor-specific isohemagglutinins of >1:4, (the UNOS cutoff), were present in five patients and reduced by plasma exchange. After transplantation, 19/21 recipients demonstrated persisting deficiency of donor-specific isohemagglutinins. Significant donor-specific isohemagglutinins levels were detected repeatedly in 2/21 recipients who have shown no clinical or biopsy evidence of rejection. All recipients survive without retransplantation and there have been no episodes of humoral rejection. We conclude it is possible for other centers to replicate the excellent results achieved in Toronto and that ABO-incompatible transplantation may be performed successfully in some patients beyond infancy with established isohemagglutinin production providing preoperative antibody removing strategies are used.

Bone mineral density (BMD) is frequently reduced in children and adolescents with Cushing’s disease (CD), but there is little follow-up data after cure. BMD was determined by dual energy X-ray absorptiometry (DEXA) in two groups of patients with CD. Group 1 comprised 8 patients, 5 males and 3 females, aged 12.4 yr (8.2–16.8), assessed at diagnosis. Group 2 comprised 11 subjects, 6 males and 5 females, diagnosed at age 13.3 yr (6.4–17.4), cured by transsphenoidal surgery (TSS) (no.=7) or TSS + pituitary irradiation (no.=4). They had measurement of BMD, at mean age of 18.3 yr (11.1–28.5), i.e.4.5 yr (0.8–11.4) after cure. Four patients, mean age 20.2 yr (17.6–22.4), had repeated DEXAscans, 1–4 times, for up to 5.8 yr. After cure, GH deficiency was present in 9 patients and treated with hGH in 8. In Group 1, patients’ L2–L4 volumetric (v)BMD Z-score was variable with a mean of −1.04 (−3.21–0.11). L2–L4 vBMD Z-score values correlated negatively with midnight cortisol (p<0.05). In Group 2, mean L2–L4 vBMD was −0.38 (−1.0–0.13); and in 7/11, mean femoral neck (FN) areal (a)BMD Z-score was 0.14 (−1.62–2.46). FN aBMD Z-score was higher than L2–L4 aBMD Z-score (p<0.05). In patients with repeated scans, mean change in L2–L4 vBMD Z-score was 0.20 (−0.15–0.45), and mean change in FN aBMD Z-score 0.03 (−0.53–0.38). These findings show variability of BMD at diagnosis and near normal BMD after cure of pediatric CD, suggesting that with appropriate replacement of pituitary hormone deficiency normal peak bone mass is achievable.

Several letters to the editor are presented. One is expressing admiration to actor Martin Dean for his genuine warmth at seeing his fans. Another is about the lifelong love of movies. The other is requesting for articles on actors Philip Holmes, Farley Granger, Susanna Foster, Robert Montgomery and directors Max Ophuls, Clarence Brown and Anatole Litvak.

We isolated, characterised, and cloned an enantio-specific amidase from Klebsiella oxytoca and used it to resolve (R,S)-3,3,3-trifluoro-2-hydroxy-2-methylpropionamide, giving (R)-3,3,3-trifluoro-2-hydroxy-2-methylpropionic acid and (S)-3,3,3-trifluoro-2-hydroxy-2-methylpropionamide. The (S)-amide could then be hydrolysed chemically to (S)-3,3,3-trifluoro-2-hydroxy-2-methylpropionic acid. The process can therefore be adapted to produce both (R)- and (S)-enantiomers of 3,3,3-trifluoro-2-hydroxy-2-methylpropionic acid, or (S)-3,3,3-trifluoro-2-hydroxy-2-methylpropionamide. The biocatalytic step is part of a combined chemical and biocatalytic route that starts from ethyl trifluoroacetoacetate. The products typically have a purity of greater than 98% and ee values of essentially 100% after isolation. The process has been used to produce 100-g amounts of the (S)-acid, and successfully scaled up to produce 100-kg amounts of the (R)-acid, with the biotransformation carried out at the 1500-L scale.

From December 1997 to April 1998, 1060 laboratory-confirmed cryptosporidiosis cases were reported in New South Wales, Australia. In a case-control study, compared with 200 controls, the 100 cases were younger (mean age 4·2 versus 7·1 years; P &lt; 0·0001), more likely to report swimming at a public pool (59% versus 38%; adjusted OR and 95% CI = 2·7; 1·4–5·1) and swimming in a dam, river or lake (OR = 4·8; 1·1–20·3) but less likely to report drinking bottled water (OR = 0·4; 0·2–0·9). In subgroup analyses, in rural areas illness was associated mainly with contact with another person with diarrhoea, and in urban areas illness was associated with swimming in a public pool. Cryptosporidium oocysts were more commonly detected in pools to which at least two notified cases had swum (P = 0·04). Outbreaks of cryptosporidiosis can be prolonged, involve multiple pools and be difficult to control.

This paper is an exploratory case study illustrating the importance of performance measures applied at the level of organisational networks. Traditional practice is limited to measuring performance independently at the level of each member of a network. This paper aims to draft basic principles of performance measurement for organisational networks and focuses on the introduction of the concept of meta-performance, i.e. network-level performance. Meta-performance is a two-dimensional construct which encapsulates (1) the concept of performance per se and (2) the concept of equity within a network. Without a fair distribution of benefits, a network does not perform effectively in its collaborative dimension and thus could fail to perform altogether. The case study illustrates the process of measuring meta-performance.

AIM: To compare indices of respiratory failure in terms of their ability to predict adverse respiratory outcomes in preterm infants. The indices evaluated were: (a) the alveolar-arterial oxygen tension difference (A-aDO(2)); (b) the ratio of arterial to alveolar oxygen tension (a/A ratio); (c) the oxygenation index (OI); (d) the fractional inspired oxygen concentration (FIO(2)). METHODS: Details of respiratory support and arterial blood gas data in the first 24 hours of life were collected in ventilated infants below 34 weeks gestation. The worst single value of a particular index in the first 24 hours was chosen to quantify the severity of respiratory failure in each infant. Receiver operating characteristic curves were constructed and areas under the curve (AUC) calculated to compare the performance of the indices in predicting death from respiratory failure and/or the development of chronic lung disease (CLD). RESULTS: A total of 155 preterm infants were studied, of whom 35 (23%) died primarily from respiratory failure and 53 of the 120 survivors (44%) developed CLD. The overall performance of the four indices in predicting death from respiratory failure ranged from 0. 77 (AUC for maximum FIO(2)) to 0.88 (AUC for minimum a/A ratio). The corresponding AUCs for gestational age and birth weight were 0.75 and 0.76 respectively. In contrast, demographic variables tended to perform better than indices of respiratory failure in predicting CLD/death. CONCLUSIONS: There was no evidence of a significant difference between the performance of the a/A ratio, A-aDO(2), and OI in predicting adverse respiratory outcomes. Use of the OI is recommended because of its ease of calculation.

BackgroundPulmonary interstitial fibrosis in children is a disease of unknown aetiology, usually associated with a poor prognosis.MethodsIn this case series we describe 11 children presenting over a 10 year period, managed conservatively and associated with a good prognosis.ResultsIn six, symptoms were present from birth and 10 had symptoms at or before 3 months. Diagnosis was made using chest computed tomography and percutaneous lung biopsy. All patients were treated with oral prednisolone. In five no steroid response was noted. One patient responded to hydroxychloroquine. Home oxygen was required in five patients. At follow up all patients are alive at a median age of 6 years (range 1 to 12 years). The two recently diagnosed children have significant symptoms, seven have dyspnoea on exercise, and two are symptom free.ConclusionThe good prognosis seen in these patients is different to previous case reports, indicating a greater than 50% mortality.

Maintenance of genomic integrity is vital to all organisms. A number of human genetic disorders, including Werner Syndrome, Bloom Syndrome and Rothmund-Thomson Syndrome, exhibit genomic instability with some phenotypic characteristics of premature aging and cancer predisposition. Presumably the aberrant cellular and clinical phenotypes in these disorders arise from defects in important DNA metabolic pathways such as replication, recombination or repair. These syndromes are all characterized by defects in a member of the RecQ family of DNA helicases. To obtain a better understanding of how these enzymes function in DNA metabolic pathways that directly influence chromosomal integrity, we have examined the effects of non-covalent DNA modifications on the catalytic activities of purified Werner (WRN) and Bloom (BLM) DNA helicases. A panel of DNA-binding ligands displaying unique properties for interacting with double helical DNA was tested for their effects on the unwinding activity of WRN and BLM helicases on a partial duplex DNA substrate. The levels of inhibition by a number of these compounds were distinct from previously reported values for viral, prokaryotic and eukaryotic helicases. The results demonstrate that BLM and WRN proteins exhibit similar sensitivity profiles to these DNA-binding ligands and are most potently inhibited by the structurally related minor groove binders distamycin A and netropsin (K(i)

AbstractObjective:To determine any adverse outcome to infants born to mothers with Antiphospholipid Syndrome (APS).Design:Case control study with retrospective data collection and prospective pediatric review.Setting:Regional Recurrent Miscarriage Clinic based at a University Teaching Hospital.Participants:Infants (n = 62) of mothers with APS, compared to 124 index cases randomly selected from the delivery register, matched for gestation and sex who delivered between 1992 and 1997.Results:Sixty two infants born to 55 women with APS were reviewed to study the neonatal outcome. The prematurity rate for the group was 10%, compared to 8.5% for the total hospital population over the same period of time. Twenty-one percent (21%) had birth weights less than or equal to the 10th centile, which was not statistically significant compared to matched controls.

About 6 per cent of the patients with infectious diseases of the spine admitted to the Spinal Unit of the Royal National Orthopaedic Hospital have been previously submitted to laminectomy. The purpose of this paper is to re-emphasize the futility of this operation for paraplegia due to spinal infection. Exceptions to this principle are described and methods of management are also considered.

Abstract: Studies on the diffusion of iodine and zinc into CdTe are reported. Each iodine profile was divided up into four distinct regions and described mathematically by a function consisting of the sum of four complementary error functions. When plotted on an Arrhenius graph, the diffusivities gave four straight line relationships with similar slopes and the Arrhenius parameters for the fastest component of D01 = (7 3). 10-11 cm2 s-1 and E1 = (0.21 0.05) eV. When extrapolated down to 20C this gave a diffusivity of 10-14 cm2 s-1 indicating that when iodine is diffused from the vapor it is not suitable as a long term stable dopant in devices where sharp impurity profiles are required. In the case of the zinc diffusions, each profile can be divided into two parts and was fitted satisfactorily by the sum of two complementary error functions giving two values of the diffusivities: Dslow due to zinc diffusion into the slice from the vapor and Dfast due to interdiffusion between a surface layer of Znx Cd1-x Te formed on the slice and the remaining CdTe.

Abstract: Studies on the diffusion of iodine into CdTe, mercury cadmium telluride (Hg0.8Cd0.2Te, referred to as MCT) and zinc cadmium telluride (Zn0.5Cd0.95Te, referred to as ZCT) in the temperature range of 20 to 600�C are compared and discussed. The concentration profiles were measured using a radiotracer sectioning technique. As with the diffusion studies using the halogens into CdTe, the profiles were composed of four parts to which a computer package consisting of the sum of four complementary error functions (erfc) gave satisfactory fits. The diffusivity for the diffusion of iodine into MCT was faster than for the diffusion into CdTe, which was faster than for the diffusion into ZCT. The high diffusivity for the fastest profile part at 20�C indicates that when iodine is diffused from the vapor into these materials, it is not a suitable long term stable dopant in devices where sharp junctions are required.

The electrical activity of iodine in CdTe is discussed when iodine is introduced into the CdTe by diffusion from the vapour phase. It is compared both with the total concentration of iodine in the diffused CdTe slices and with the electrical activity in CdTe slices which have been annealed under Cd- and Te-saturated vapour pressures. Iodine-diffused slices of CdTe were profiled by secondary ion mass spectrometry (SIMS) to obtain the total iodine concentration and by capacitance-voltage (C-V) techniques to obtain the net concentration of electrically active iodine. After annealing with iodine in the form of Cdl2, the slices were p-type, similar to those obtained when CdTe was annealed in either excess Te or Cd vapour, and they showed no significant increase in electrical activity. If Cd was added to the Cdl2 diffusion source or the CdTe was given a subsequent anneal in cadmium vapour, the slices became n-type. The results indicated that in all cases a neutral layer composed of Cd nIm (m and n are integers) formed on the surface layers, whereas if Cd was involved in the diffusion, some of the iodine existed in an electrically active form deeper into the slice with a maximum concentration of active carriers given by ND - NA ≈ 10¹⁷ cm⁻³. © 1997 John Wiley & Sons Ltd.

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Using current Computer Aided Design (CAD) and Finite Element Analysis (FEA) pre-processing systems, a large proportion of the analyst's time is spent preparing an idealised model of a part or structure for analysis. Although complete geometric information for the part is often available in the form of a solid model, this is seldom taken advantage of because of the amount of time required to simplify and idealise the geometry for the subsequent meshing stage. In fact, analysts often find it easier to reconstruct the idealised model from scratch, a process which is error prone and prohibits linking the analysis results to the product in a formal way. This paper gives an overview of a future system which would allow and encourage more automated CAD-FEA transformation using tools that operate directly on the solid model. Functional components for such a system are discussed together with issues that should be addressed in order to achieve a fully integrated CAD-FEA transformtion scheme. The overall aim is to make the transition from a solid model to an idealised model suitable for analysis an easier, more robust and less time-consuming task.

The compatibility of iodine and CdTe is discussed and methods by which CdTe can be doped with iodine from the vapour phase using closed tube diffusion techniques are described. At elevated temperatures ( ? 100 ‡C) an elemental iodine diffusion source was found to be unsuitable since it caused severe degradation of the CdTe surface, even when elemental Cd was added to the diffusion source. To overcome this difficulty the compound CdI2 was produced and used successfully at temperatures up to 600 ‡C.

The lipids of Thermus aquaticus YT1, Thermus thermophilus HB8, Thermus sp. strains H and J (from Icelandic hot springs), and Thermus sp. strain NH (from domestic hot water) have been investigated. Each strain contained two major components, a glycolipid and a glycophospholipid, which have been isolated and analyzed. All of the strains contained as the principal component (41 to 57% of total lipid) a diacyldiglycosyl-(N-acyl)glycosaminylglucosylglycerol, but the five glycolipids differed in carbohydrate composition. The glycophospholipid appeared to be identical in each strain and contained an N-acylglucosamine residue. The principal fatty acids were C15 and C17 branched-chain compounds. This unique polar lipid composition should be of value in the classification of other thermophiles in the genus Thermus. The exceptionally high carbohydrate content of the lipids of these extreme thermophiles may be of significance in relation to the molecular basis of thermophily.

Many supporters of official English have accused U.S. Hispanics of refusing to learn English and rejecting the traditional assimilationist model by clinging to their ethnolinguistic identity. An analysis of U.S. Census data from the last thirty years refutes these claims. The picture of U.S. Hispanic maintenance of ethnolinguistic identity has evolved. Here we show that while adult Spanish loyalty has decreased, youth Spanish loyalty has increased; however, Spanish maintenance does not occur at the expense of English proficiency. Once recent immigrants are subtracted from the Hispanic population, U.S. Census figures show clearly that long-term limited English proficiency has decreased substantially. This analysis clearly supports the conclusions of experts who have noted that Hispanic youth are embracing a bilingual model, one which allows them to maintain their ethnolinguistic identity while acquiring the English skills necessary for success in the United States.

A partial phase diagram of the cadmium oxide-tellurium dioxide system is presented. The results of attempts to prepare substantial single crystals of congruently and incongruently melting phases are recorded along with the properties of such crystals. It is shown that one of the two compounds obtained as single crystals, namely cadmium di-tellurite, possesses a mica-like nature with excellent insulating properties, but is not piezo-electric. The other, namely cadmium mono-tellurite, can exist in two forms, one of which is piezo-electric.

The effects of low pass filtering on the brainstem auditory evoked potential (BAEP) were studied in the adult male rat. The bandpass of the recording system was progressively widened while the cut-off frequency of the high pass filter remained constant at 3.2 Hz. When the high frequency cut-off was 320 Hz or less, the principal waveform recorded in response to a click stimulus was a slow positive-negative complex. As the high frequency setting was raised from 800 Hz to 3.2 kHz, the slow components of the brainstem were replaced by four fast BAEP waves (I, II, III and IV). As the bandpass widened there was an increase in amplitude and a decrease in the absolute latency of all four fast waves in the order of 0.1 ms although the wave I–IV interpeak latency remained unaffected. The results confirm that the high frequency components of the BAEP are underlain by a slow positivity of uncertain origin followed by a slow negativity which probably arises within the inferior colliculus.

Product data models can be viewed as a class of semantic data models which take into account the needs of engineering data. In this paper the characteristics for semantic data models defined by Peckham and Maryanski [8] are taken as a starting point. The relevance of these characteristics to product data is shown. The capabilities of a prototype product description system are described in relation to the same characteristics. Additional data modeling characteristics such as parametrization and data sharing, which have been introduced to support engineering design, are then described. These can be viewed as extending beyond the accepted capabilities of semantic data models.

Densification studies of sintered stainless steel powder blends have shown that the introduction of delta-ferrite into the micro structure increases substantially the sintering rate of the compact. Model experiments, in which spherical particles of a 316 powder were sintered on several different base plates including iron, 18Cr–12Ni stainless steel, iron–12% nickel, have been carried out to provide more detailed information. Quantitative observations have been made on the rate of neck growth and on the compositional gradients which develop between particle and plate. It has been found that the sintering rates were very sensitive to the composition of the base plate and to the presence of austenite/ferrite interfaces. Micro-examination and the use of electron probe microanalysis indicate that interdiffusion of elements between particles and plates is by both surface and volume diffusion.

The incorporation of deuterium from deuterium oxide into the free amino acids of the cotyledons of Sinapis alba L. was studied by gas chromatography-mass spectrometry and was similar, both qualitatively and quantitatively, after incubation of the seedlings in darkness or far-red light. The results support studies which show that phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) is synthesised de novo, rather than activated, in response to far-red light.

The II-VI semiconductor cadmium mercury telluride has been studied with a low-energy positron beam. Differences in the variation of the Doppler line-shape parameter as a function of positron implantation energy have been observed for annealed and as-grown samples. A diffusion model analysis of the results indicates large changes in the defect concentration in the bulk due to the annealing. This change is attributed to the difference in mercury vacancy concentration in the samples.

Aim: To determine the frequency and nature of feeding problems in infants with oxygen dependent chronic lung disease (CLD).Methods: A questionnaire regarding the feeding history of the infant was administered to parents of infants with CLD and a control group.Results: Forty‐seven infants with CLD and 35 control infants were studied. Fewer infants in the CLD group fed well once established on milk feeds compared to the control group (49% vs. 77%; P<0.05) and a greater number had significant vomiting under the age of 6 months when compared to controls (66% vs. 37%; P<0.05). The CLD group had a significantly higher incidence of feeding problems compared to the controls, including recurrent spitting out of food (34% vs. 3%), refusal of food (38% vs. 26%) or gagging on food (47% vs. 6%). Twenty‐three per cent of infants in the CLD group required enteral feeding beyond 3 months of age, and 19% had a second episode of enteral feeding.Conclusion: The incidence of feeding problems in infants with CLD is high. Strategies aimed at reducing these problems need to be identified and evaluated.