Measuring the density structure of an accretion hot spot.

Magnetospheric accretion models predict that matter from protoplanetary disks accretes onto stars via funnel flows, which follow stellar magnetic field lines and shock on the stellar surfaces1-3, leaving hot spots with density gradients4-6. Previous work has provided observational evidence of varying density in hot spots7, but these observations were not sensitive to the radial density distribution. Attempts have been made to measure this distribution using X-ray observations8-10; however, X-ray emission traces only a fraction of the hot spot11,12 and also coronal emission13,14. Here we report periodic ultraviolet and optical light curves of the accreting star GM Aurigae, which have a time lag of about one day between their peaks. The periodicity arises because the source of the ultraviolet and optical emission moves into and out of view as it rotates along with the star. The time lag indicates a difference in the spatial distribution of ultraviolet and optical brightness over the stellar surface. Within the framework of a magnetospheric accretion model, this finding indicates the presence of a radial density gradient in a hot spot on the stellar surface, because regions of the hot spot with different densities have different temperatures and therefore emit radiation at different wavelengths.

Effect of temperature on the dissolution of the lead (II) carbonate hydrocerussite for varying pH and dissolved inorganic carbon conditions.

The effect of temperature on the solubility of lead-bearing solid phases in water distribution systems for different water chemistry conditions remains unclear although lead concentrations are known to vary seasonally. The study objective is to explore the effect of temperature on the solubility of the lead(II) carbonate hydrocerussite under varying pH and DIC conditions. This is achieved through batch dissolution experiments conducted at multiple pHs (6-10) and DIC concentrations (20-200 mg CL-1) at temperatures ranging from 5 to 40 °C. A thermodynamic model was also applied to evaluate the model's ability to predict temperature effects on lead(II) carbonate solubility including solid phase transformations. In general, increasing temperature increased total dissolved lead at high pHs and the effect of temperature was greater for high DIC conditions, particularly for pH > 8. Temperature also influenced the pH at which the dominant lead(II) solid phase switched from hydrocerussite to cerussite (occurred between pH 7.25 to 10). Finally, the model was able to capture the overall trends observed despite thermodynamic data limitations. While this study focuses on a simple lead solid-aqueous system, findings provide important insights regarding the way in which temperature and water chemistry interact to affect lead concentrations.

Efficient management of new patient referrals to a breast service: the safe introduction of an advanced nurse practitioner-led telephone breast pain service.

INTRODUCTION: There has been an almost 100% increase in referrals to breast cancer diagnostic clinics in the past decade. Breaching of the two-week cancer referral target is now commonplace, potentially delaying diagnoses of breast malignancy in many women. Almost one in five of these referrals are women with mastalgia, not a symptom linked to breast cancer. The objective of the study was the safe introduction of an advanced nurse practitioner-led telephone service for women with mastalgia to improve the service for women and create capacity for those with "red flag" breast symptoms. METHODS: Referrals to clinic were triaged, women with mastalgia only were directed to a telephone-based assessment clinic and symptoms evaluated using a multidisciplinary created proforma. RESULTS: Within 23 months, 1,427 women were assessed in the breast pain telephone assessment clinic: 863 (61%) were aged over 40 and 564 (39%) aged under 40. A total of 1,238 underwent telephone assessment. Reassurance and discharge only was needed for 365 (26%). The aetiology of pain was identified as musculoskeletal in 1,104/1,238 (89%) of patients, with only 39/1,238 (3.2%) identified as having true breast pain. Additional symptoms were mentioned by 264 women (18%) during the consultation; all immediately redirected back to a diagnostic clinic. Mammography was undertaken in 609 women (43%). Seven women (0.6%) were diagnosed with a breast malignancy. Patient survey indicated that 93% of patients were satisfied with the care received and 97% said they would recommend the service to a family member or friend. CONCLUSIONS: Although face-to-face assessments for breast pain remain the standard practice in many breast units, data indicating the safety of a telephone assessment clinic, along with high levels of patient satisfaction, question whether services can be delivered differently.

Naphthenic acid fraction compounds reduce the reproductive success of wood frogs (Rana sylvatica) by affecting offspring viability.

Understanding the toxicity of organic compounds in oil sands process-affected water (OSPW) is necessary to inform the development of environmental guidelines related to wastewater management in Canada's oil sands region. In the present study, we investigated the effects of naphthenic acid fraction compounds (NAFCs), one of the most toxic components of OSPW, on mating behaviour, fertility, and offspring viability in the wood frog (Rana sylvatica). Wild adult wood frogs were exposed separately from the opposite sex to 0, 5, or 10 mg/L of OSPW-derived NAFCs for 24 h and then combined in outdoor lake water mesocosms containing the same NAFC concentrations (n = 2 males and 1 female per mesocosm, n = 3 mesocosms per treatment). Mating events were recorded for 48 h and egg masses were measured to determine adult fertility. NAFC exposure had no significant effect on mating behaviour (probability of amplexus and oviposition, amplexus and oviposition latency, total duration of amplexus and number of amplectic events) or fertility (fertilization success and clutch size). Tadpoles (50 individuals per mesocosm at hatching, and 15 individuals per mesocosm from 42 d post-hatch) were reared in the same mesocosms under chronic NAFC exposure until metamorphic climax (61-85 d after hatching). Offspring exposed to 10 mg/L NAFCs during development were less likely to survive and complete metamorphosis, grew at a reduced rate, and displayed more frequent morphological abnormalities. These abnormalities included limb anomalies at metamorphosis, described for the first time after NAFC exposure. The results of this study suggest that NAFCs reduce wood frog reproductive success through declines in offspring viability and therefore raise the concern that exposure to NAFCs during reproduction and development may affect the recruitment of native amphibian populations in the oil sands region.

Reconciling Assumptions in Bottom-Up and Top-Down Approaches for Estimating Aerosol Emission Rates From Wildland Fires Using Observations From FIREX-AQ.

Accurate fire emissions inventories are crucial to predict the impacts of wildland fires on air quality and atmospheric composition. Two traditional approaches are widely used to calculate fire emissions: a satellite-based top-down approach and a fuels-based bottom-up approach. However, these methods often considerably disagree on the amount of particulate mass emitted from fires. Previously available observational datasets tended to be sparse, and lacked the statistics needed to resolve these methodological discrepancies. Here, we leverage the extensive and comprehensive airborne in situ and remote sensing measurements of smoke plumes from the recent Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) campaign to statistically assess the skill of the two traditional approaches. We use detailed campaign observations to calculate and compare emission rates at an exceptionally high-resolution using three separate approaches: top-down, bottom-up, and a novel approach based entirely on integrated airborne in situ measurements. We then compute the daily average of these high-resolution estimates and compare with estimates from lower resolution, global top-down and bottom-up inventories. We uncover strong, linear relationships between all of the high-resolution emission rate estimates in aggregate, however no single approach is capable of capturing the emission characteristics of every fire. Global inventory emission rate estimates exhibited weaker correlations with the high-resolution approaches and displayed evidence of systematic bias. The disparity between the low-resolution global inventories and the high-resolution approaches is likely caused by high levels of uncertainty in essential variables used in bottom-up inventories and imperfect assumptions in top-down inventories.

A corepressor and chicken ovalbumin upstream promoter transcriptional factor proteins modulate peroxisome proliferator-activated receptor-gamma2/retinoid X receptor alpha-activated transcription from the murine lipoprotein lipase promoter.

Complex physiological stimuli differentially regulate the tissue-specific transcription of the lipoprotein lipase (LPL) gene. A conserved DNA recognition element (-171 to -149 bp) within the promoter functions as a transcriptional enhancer when bound by the peroxisome proliferator-activated receptor-gamma2 (PPARgamma2)/retinoid X receptor alpha (RXRalpha) heterodimer, but serves as a transcriptional silencer in the presence of unidentified double and single stranded DNA-binding proteins. To address this apparent paradox, the current study examined the effect of two classes of candidate comodulatory proteins, COUP-TF (chicken ovalbumin upstream promoter transcriptional factor) and the corepressor SMRT (silencing mediator of retinoic acid receptor and thyroid receptor). The expression of COUP-TF was detected by Western and Northern blots in a preadipocyte 3T3-L1 cell model during periods corresponding to increased LPL transcription. Cotransfection of COUP-TF expression constructs in the renal epithelial 293T cell line significantly increased transcription from the LPL promoter in synergy with PPARgamma2/RXRalpha heterodimers. The COUP-TFII (ARP-1) protein specifically bound the LPL PPAR recognition element inelectromobility shift assays and interacted directly with the ligand-binding domain of PPARgamma in pull-down experiments. In contrast, cotransfection of SMRT repressed PPARgamma2/ RXRalpha-mediated LPL transcription in the absence or presence of COUP-TFII (ARP-1). The interaction between PPARgamma2 and SMRT localized to the receptor-interactive domain 2 (amino acids 1260-1495) of the SMRT protein based on cotransfection and pull-down assays. These in vitro data indicate that COUP-TF proteins and SMRT modulate PPARgamma-mediated LPL transcription in the 293T cell line.

Nuclear hormone receptors and adipogenesis.

Adipocytes provide a model cell system for exploring the complexities of nuclear hormone receptor transcriptional regulation. Adipocytes produce lipid and cholesterol metabolites which can serve as activating ligands for many of the classic and "orphan" nuclear hormone receptors. At the same time, nuclear hormone receptors directly control adipocyte commitment. The recently described nuclear hormone receptor coactivators and corepressors provide an additional level of complexity to this system. This review emphasizes available in vitro and in vivo models and discusses them in the context of current controversies and future experimental directions.

The function of adipocytes in the bone marrow stroma: an update.

The adipocyte is the most abundant stromal cell phenotype in adult human bone marrow. Four hypotheses may explain their function. First, adipocytes may serve a passive role, simply occupying excess space in the bone marrow cavity. Second, they may play an active role in systemic lipid metabolism. Third, adipocytes may provide a localized energy reservoir in the bone marrow. Or fourth, marrow adipocytes may contribute directly to the promotion of hematopoiesis and influence osteogenesis. This article reviews recent findings concerning bone marrow adipocyte morphology and physiology, the transcriptional and cytokine mechanisms regulating their differentiation, and the interrelationships existing between bone marrow adipocytes, hematopoiesis, and osteogenesis. Overall, these data lend support to a "plastic" model of bone marrow stromal cell differentiation; adipocytes may share common functions with stromal stem cells, osteoblasts, and hematopoietic supportive cells.

Inactivation of enteric microbes in water by electro-chemical oxidant from brine (NaCl) and free chlorine.

Oxidant solutions of mostly free chlorine can be electrochemically produced on-site from brine (NaCl) solution and used to disinfect water at the household or community level. In this study electrochemical oxidant (ECO) from brine and free chlorine were evaluated under laboratory conditions for inactivation of test microbes. Purified suspensions of Escherichia coli, the rugose strain of Vibrio cholerae, Clostridium perfringens spores, MS2 coliphage and Cryptosporidium parvum oocysts were treated with 2 mg/L or 5 mg/L solutions of ECO or free chlorine at 5 degrees C and 25 degrees C and pH 6, 8, and 10 (pH 7 and 25 degrees C only for C. parvum oocysts) for contact times <60 min. Under nearly all conditions, inactivation kinetics were more rapid for E. coli, V. cholerae, C. perfringens spores and MS2 coliphage with ECO than with free chlorine. ECO reduced E. coli, V. cholerae and MS2 by >4 log10 within 30 min and C. perfringens spores by >2 log10 within 10 min at pH 8 and 25 degrees C. Contrary to previous results, however, C. parvum oocysts were not inactivated by ECO, and the reasons for this difference are uncertain. The on-site electrolytic generation of oxidants from brine provided a convenient and inexpensive disinfectant containing free chlorine that was effective against many enteric microbes, for the treatment of household and community drinking-water supplies worldwide. However, the effectiveness of such oxidants for inactivating C. parvum oocysts was variable and sometimes ineffective.

Follow-up self care assessment.

The following study was undertaken to evaluate the level of slef-care activities of severely disabled patients discharged from the G. F. Strong Rehabilitation Centre to extended care units (FCU). The results may offer significant information with regard to the ongoing rehabilitation program at the Centre, and could have implications in terms of total management for severely disabled patients in the future.

The role of computed tomography in terminal ballistic analysis.

Terminal ballistics concerns the science of projectile behaviour within a target and includes wound ballistics that considers what happens when a projectile strikes a living being. A number of soft tissue ballistic simulants have been used to assess the damage to tissue caused by projectiles. Standard assessment of these materials, such as ballistic soap or ordnance gelatine, requires the block to be opened or that a mould to be made to visualize the wound track. This is time consuming and may affect the accuracy of the findings especially if the block dries and alters shape during the process. Therefore, accurate numerical analysis of the permanent or temporary cavity is limited. Computed tomography (CT) potentially offers a quicker non-invasive analysis tool for this task. Four commercially purchased ballistic glycerine soap blocks were used. Each had a single firearm discharged into it from a distance of approximately 15 cm using both gunshot and shotgun projectiles. After discharge, each block was imaged by a modern 16 slice multi-detector CT scanner and analysed using 3-D reconstruction software. Using the anterior-posterior and lateral scout views and the multi-plane reconstructed images, it was possible to visualize the temporary cavity, as well as the fragmentation and dispersal pattern of the projectiles, the distance travelled and angle of dispersal within the block of each projectile or fragment. A virtual cast of the temporary cavity can be also be made. Multi-detector CT with 3-D analysis software is shown to create a reliable permanent record of the projectile path allowing rapid analysis of different firearms and projectiles.

The molecule-group schema of memory: storage, recognition and retrieval.

A new schema, the molecule-group schema, explains memory storage, recognition and retrieval. The schema consists of three postulates about molecular specificity, grouping, and diffusion. In the schema, the physical memory trace consists of a stable group of different kinds of highly specific molecules. The schema is intended to provide an alternative to the widely known synaptic-change schema, in which it is assumed that changes of synaptic efficacies constitute the memory trace. The new schema is used to develop a particular model of memory. In the model, recognition occurs when specific intracellular "endotransmitters" react with complementary "endoreceptors" in the same cell. Retrieval, modelled as the process whereby memory causes the recurrence of a previously experienced pattern of neural activity, occurs when a group of pools of endotransmitters, located within an intracellular memory organelle, is released, allowing the endotransmitters to diffuse to the periphery of the cell body. The model suffices to explain long-term and short-term memory of events as well as innate memory.

Application of a new rating scale of brain dysfunction to monitoring rehabilitation in 65 patients with severe head injury.

Sixty-five patients with severe head injury sustained in motor vehicle accidents (MVA) are the subject of the prospective investigation. For assessment of results of a particular treatment, planning of long-range management and predicting the outcome in terms of employment or of self-care, it is essential to monitor sequentially the progress of recovery. A comprehensive semiquantitative rating Scale g was developed and its application during repeated examinations demonstrated. The Scale g is open-ended, as it allows physicians and investigators in the health field to produce their own schedules of any disability provided that seven levels of that particular dysfunction are defined according to the principles of Scale g. The progress of recovery in motor deficits, dysarthria, mental impairment, and self-care was assessed using appropriate schedules according to Scale g in 65 inpatients at their first admission to the rehabilitation center and at their discharge. The change was made evident by showing patients' advancement, if present, to the higher functional level. It was estimated at the time of discharge that 23.1% can be expected to return to full-time employment, 38.5% are likely to perform part-time lesser work, 13.8% may be able to perform certain, non remunerative chores at home, 24.6% would not be able to do any work--about one-third of them will permanently require long-care facility.

CAAT/enhancer binding proteins directly modulate transcription from the peroxisome proliferator-activated receptor gamma 2 promoter.

The CCAAT/enhancer binding proteins (C/EBPs) and the peroxisome proliferator-activated receptors (PPARs) together regulate adipogenesis. The current work uses co-transfection studies to examine the C/ EBP dependence of PPAR gamma 2 transcription. Both C/ EBP alpha and C/EBP delta expression vectors activated transcription from a PPAR gamma 2 promoter/luciferase expression vector by 5-6 fold in UMR106 cells. The simultaneous transfection of the C/EBP homologous protein (CHOP) (also known as growth arrest DNA damage protein 153 or gadd153) inhibited this C/EBP-dependent activation in a concentration dependent manner. The CHOP protein is known to heterodimerize with other C/EBP proteins to form transcriptionally inactive complexes. Mutation of the two C/EBP DNA recognition elements at -340 bp and -327 bp within the PPAR gamma 2 promoter reduced the inductive effects of both C/EBP alpha and C/EBP delta. These findings demonstrate that proteins within the C/EBP family directly modulate transcription from the PPAR gamma 2 promoter.

DNA sequence analysis of an abl-related gene in the blow fly, Calliphora erythrocephala.

The Ceabl locus is a member of a small family of abl-related sequences in C. erythrocephala. The catalytic, SH2 and SH3 domains of the Ceabl-encoded protein show greater than 75% sequence identity to vertebrate abl protein tyrosine kinases and greater than 95% identity to the D. melanogaster abl polypeptide. Ceabl diverges from the vertebrate proteins, however, at the extreme amino terminus, near the beginning of the vertebrate abl exon involved in differential splicing. The carboxyl region shows no detectable similarity to the vertebrate abl proteins, while identity to Drosophila abl falls to 55%. Regions conserved between the two dipteran genes revealed no strong similarities to other proteins in the Genbank and EMBL databases.

Lower extremity bracing in paraplegia--a follow-up study.

This retrospective study of 98 paraplegics was carried out to determine the utilisation of long leg braces prescribed during their rehabilitation training. An analysis of their age, duration of disability and physical status was done. Other factors such as work status, decubiti, bowel and bladder functions were also considered.

DNA bending is induced by binding of the peroxisome proliferator-activated receptor gamma 2 heterodimer to its response element in the murine lipoprotein lipase promoter.

The peroxisome proliferator activated receptor gamma 2 (PPAR gamma 2) is a critical transcriptional regulator of adipogenesis. Lipoprotein lipase is one of the earliest genes induced following exposure of pre-adipocytes to PPAR gamma 2 ligands such as the thiazolidinediones. A unique PPAR gamma 2 DNA recognition element was mapped to the region between -171 to -149 bp of the murine LPL promoter, based on transfection analysis of deletion constructs and gel retention assays using bacterially expressed, affinity purified recombinant proteins. Circular permutation analysis determined that binding of the PPAR gamma 2/retinoic acid X receptor (RXR) heterodimer to its LPL promoter recognition element induced DNA bending at an angle of approximately 46 degrees. Parallel studies using an optimal PPAR recognition element obtained a comparable bending angle of 56 degrees. This is the first demonstration that binding of a PPAR protein to its recognition element causes a distortion of the DNA configuration. It indicates that PPAR gamma 2 utilizes a common mechanism shared by other nuclear hormone receptor proteins reported to induce bending at their DNA binding sites.

Analysis of the native murine bone morphogenetic protein serine threonine kinase type I receptor (ALK-3).

The bone morphogenetic proteins, members of the transforming growth factor-beta cytokine family, induce the osteoblast phenotype and promote osteogenesis in the bone marrow stroma. Simultaneously, these cytokines inhibit other mesodermal differentiation pathways, such as adipogenesis and myogenesis. The receptors for the bone morphogenetic proteins belong to a family of transmembrane serine/ threonine kinase TGF beta type I and type II receptor proteins. In man, these include the activin receptor like kinase-3 (ALK-3), a type I receptor protein. We have used a polyclonal antibody to examine the expression of the native murine ALK-3 protein in murine tissues and bone morphogenetic protein-responsive cell lines. On Western blot analyses, we found that the native 85 kDa native ALK-3 protein was expressed in a number of murine tissues; protein and mRNA levels did not necessarily correlate. Two bone morphogenetic protein-responsive cell lines, BMS2 bone marrow stromal cells and C2C12 myoblasts, expressed the ALK-3 protein constitutively. Cell differentiation was accompanied by modest changes in ALK-3 protein levels. Immunoprecipitation of the ALK-3 protein cross linked to [125I] BMP-4 revealed two major receptor complexes of approximately 90 kDa and 170 kDa in size. Biotin surface-labeling experiments revealed that the 85 kDa ALK-3 protein was constitutively associated with a novel 140 kDa surface glycoprotein. Deglycosylation reduced the protein's size to 116 kDa, comparable in size to that of the recently described BMP type II receptor. These findings support the current model that BMP interacts with a pre-existing complex consisting of a type I and type II receptor protein.

Polyarthritis associated with gastric carcinoma.

In a 68-year-old man who had polyarthritis associated with gastric carcinoma surgical resection of the tumour was accompanied by prompt resolution of the arthritic syndrome. In 11 years of follow-up the arthritis has remained in complete remission and there has been no recurrence of the carcinoma. An awareness that polyarthritis may be a presenting manifestation of an underlying carcinoma may, especially in an elderly person, lead to early recognition and treatment of the malignant disease.