Exploring how fire spread mode shapes the composition of pyrogenic carbon from burning forest litter fuels in a combustion wind tunnel.

In this study, solid state 13C nuclear magnetic resonance (NMR) spectroscopy was used to explore the carbon-containing functional groups present in pyrogenic carbon (PyC) produced during different fire spread modes to forest litter fuels from a dry sclerophyll eucalypt forest burnt in a combustion wind tunnel. A replicated experimental study was performed using three different fire spread modes: heading fires (i.e. fires which spread with the wind), flanking fires (i.e. fires which spread perpendicular to the wind) and backing fires (i.e. fires which spread against the wind). In addition to 13C NMR measurements of PyC, detailed fire behaviour measurements were recorded during experiments. Experiments showed that heading fires produced significantly more aryl carbon in ash samples than flanking fires. All other experimental comparisons for burnt fuel samples involving different fire spread modes were statistically insignificant. Principal component analysis (PCA) was used to explore the relationship between 13C NMR functional groups and fire behaviour observations. Results from PCA indicate that maximising the residence time of high temperature combustion and the combustion factor (i.e. the fraction of pre-fire biomass consumed by fire) could be a method for increasing the amount of aryl carbon in PyC. Maximising the amount of aryl carbon could be beneficial for the overall PyC balance from fire, since more recalcitrant carbon (e.g. carbon with a higher aryl carbon content) that is not emitted to the atmosphere has been shown to have longer residence times in environmental media such as soils or sediments.

The effect of fire affected Pinus radiata litter and char addition on soil nitrogen cycling.

In pine forest litters, decomposition rate is directly affected by the pathway the needle followed to the ground, whether that was via programmed apoptosis and abscission or via stress induced loss through branch damage or tree death. Stress induced losses may occur due to fire damage, which leads to a post-fire litter layer composed of non-senescent debris that fell during or after the event. This study investigates decomposition and nitrogen cycling in soils amended with two litters from Pinus radiata plantations that had different recent fire histories. Litters were incubated in the presence or absence of field collected char for up to 94 days. These soil treatments were analysed for microbial activity (soil respiration) and N pools (microbial, mineral, and potentially mineralisable). Soil and litter treatments were additionally incubated in the presence of ammonium nitrate solution to determine N absorption potential of the litters. Respiration was greatest in soils that received fire affected (FA) litter regardless of the presence or absence of char. Nitrogen pools were largely similar between the control (no litter) treatment and not fire affected (NFA) litter treatments. Measured N pools were exceedingly low (92% of samples <2 µg-N g soil-1 where detected) or not detectable (37% of samples below detection limits) in all FA litter treatments at most times. Char appeared inert throughout and had no effects on microbial activity or nitrogen cycling. This study indicates that fire affected pine litter collected four months post fire has strong N absorption properties with or without the presence of char. The presence of fire affected litter is likely to affect N availability for regeneration of forest growth.

Microbial DNA profiling by multiplex terminal restriction fragment length polymorphism for forensic comparison of soil and the influence of sample condition.

AIMS: To evaluate: (i) the impact of air-drying on bacterial, archaeal and fungal soil DNA profiles and (ii) the potential use of multiplex-terminal restriction fragment length polymorphism (M-TRFLP) as a tool for forensic comparison of soil. METHODS AND RESULTS: An M-TRFLP approach was used to profile bacterial, archaeal and fungal DNA profiles from five different soil sites. Air-drying soil significantly reduced the quantity of DNA but the number of operational taxanomic units (OTU) was unaffected. The impact of air-drying on soil DNA profiles was dependent on soil site and microbial primers. Fungal profiles were altered the least by air-drying. For prokaryotic profiles, air-drying altered the relative similarity/dissimilarity between soil sites. The M-TRFLP approach was more discriminatory compared with soil colour and single-taxa profiling, but did not significantly improve resolution between two similar soils. CONCLUSIONS: Of those tested, soil fungi were potentially the more robust target for application to soil forensic studies as they were altered less by air-drying and provided clear discrimination of soils from different sites. The M-TRFLP method demonstrated potential to achieve greater resolution, discriminating the soil sites based on both bacterial and fungal components. SIGNIFICANCE AND IMPACT OF THE STUDY: Soil DNA profiling has potential as a forensic tool, but sample condition and the appropriate selection of microbial target taxa must be considered.

Transcripts of Grg4, a murine groucho-related gene, are detected in adjacent tissues to other murine neurogenic gene homologues during embryonic development.

The groucho-related genes (Grg) of the mouse comprise at least four family members. In Drosophila, groucho is one of the neurogenic genes that participates in the Notch signalling pathway. The Groucho protein interacts with Hairy-related transcription factors to regulate segmentation, neurogenesis and sex determination. Thus, by analogy to the Drosophila proteins, murine Grg proteins may interact with mammalian Hairy and E(spl) homologues (Hes proteins) and take part in a signalling pathway downstream of murine Notch. We have isolated murine Grg4 cDNAs and examined Grg4 expression during embryogenesis. Transcripts of Grg4 were detected in proliferating epithelial tissues undergoing mesenchymal induction, overlapping with Grg3, Notch1 and Hes1 expression. Grg4 was also expressed in the central nervous system and somites, but in cells adjacent to Grg3-, Notch1-, and Hes1-expressing cells. This distinct pattern of expression suggests a role for Grg4 in later stages of cell differentiation than for the other mouse neurogenic gene homologues.

The effects of corticosterone on 5-HT receptor function in rodents.

In the mouse, administration of corticosterone-21-acetate (30 mg/kg, s.c. daily) for 3 and 10 days produced an attenuation of the hypothermic response to the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), which was not present after administration for 1 day. A similar effect was observed in the rat after administration of corticosterone-21-acetate (30 mg/kg, s.c. daily) for 10 days. Mice which had been given corticosterone for 10 days displayed the serotonin syndrome when injected with 5-hydroxytryptophan (5-HTP, 100 mg/kg, s.c.), 15 min after injection of carbidopa (25 mg/kg, i.p.). This was not seen in control animals. The serotonin syndrome was also induced in mice using 8-OH-DPAT; this increased in a dose-dependent manner and could be significantly decreased by pre-treatment with 1-(2-methoxyphenyl)-4-(4-phthalimidobutyl)-piperazine (NAN-190 5 mg/kg, i.p., 30 min prior to administration of 8-OH-DPAT), a 5-HT1A receptor antagonist. Administration of corticosterone (30 mg/kg, s.c. daily) did not significantly alter the serotonin syndrome induced in treated mice, compared with controls. Mice pre-treated for 3 or 10 days with corticosterone did not differ from controls in the number of head-twitches induced by 5-HTP and carbidopa or 5-methoxy-N,N-dimethyltryptamine, nor did they differ from controls in their response to the putative 5-HT1B agonist 5-methoxy-3 (1,2,3,6-tetrahydropyridin-4-yl)1-H indole (RU 24969, 3 mg/kg, i.p.).(ABSTRACT TRUNCATED AT 250 WORDS)

Octreotide: a long-acting inhibitor of endogenous hormone secretion for human metabolic investigations.

Octreotide is a recently available, FDA-approved, long-acting analog of somatostatin. The efficacy and tolerability of octreotide were evaluated in a series of protocols in healthy volunteers to assess its suitability for use in clinical investigations involving short-term inhibition of endogenous hormone secretion. Prolonged (270 minutes) hyperglycemic clamps were used to assess octreotide-mediated suppression of glucose-stimulated endogenous insulin secretion. Compared with a saline-control infusion, octreotide (30 ng/kg/min) suppressed stimulated insulin (P < .0001) and C-peptide (P < .0001) concentrations to basal levels. During insulin-induced hypoglycemia (plasma glucose < 40 mg/dL), octreotide (30 ng/kg/min) effectively suppressed the secretion of glucagon (P < .05) and growth hormone (P < .0005). In islet cell clamp studies, octreotide (30 ng/kg/min) suppressed C-peptide (P < .001), glucagon (P < .01), and growth hormone concentrations to below basal (fasting) levels in all subjects. Subsequent infusion of exogenous insulin, glucagon, and growth hormone resulted in predictable and stable concentrations of each hormone during octreotide-mediated suppression of their endogenous secretion. Consistent with the long half-life of octreotide (approximately 90 minutes), the concentrations of all three hormones remained suppressed below basal levels throughout a 60-minute observation period following the termination of octreotide infusion. In separate high-dose octreotide infusion studies, octreotide (60 ng/kg/min) did not produce any apparent additional metabolic effects, but was associated with an unacceptable degree of gastrointestinal side effects.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of the effects of two dinitroanilines against Cryptosporidium parvum in vitro and in vivo in neonatal mice and rats.

The effects of two dinitroanilines, oryzalin and trifluralin, were compared against Cryptosporidium parvum, in vitro using HCT-8 cells and in vivo using neonatal Swiss ARC mice and Wistar neonatal rats. In vitro, oryzalin and trifluralin exhibited IC(50) values (concentration necessary to cause a 50% inhibition) of 750 and 800 nM, respectively. A viability assay showed that neither compound produced a cytotoxic effect on the host cells at concentrations as high as 1 microM. The in vivo component of this study consisted of inoculation of neonatal mice and neonatal rats with 10(5) viable oocysts of C. parvum per animal and the subsequent treatment of this infection with trifluralin and oryzalin administered via gastric intubation. At doses of 100 mg kg(-1) body weight administered twice daily for 3 consecutive days, trifluralin had no statistically significant effect on the number of oocysts recovered from the gut of either rats or mice compared with controls, whereas at the same concentration, oryzalin caused 90 and 79% inhibition of oocysts recovered from mice and rats, respectively.

A comparison of the effects of a benzimidazole and the dinitroanilines against Leishmania infantum.

Leishmania infantum promastigotes and amastigotes were axenically cultured and exposed to the known tubulin binding compounds, the dinitroanilines, trifluralin, benfluralin, pendimethalin, oryzalin and the precursor of the dinitroanilines, chloralin, as well as isomers of chloralin and trifluralin and to the benzimidazole, albendazole. Drug induced inhibition was observed using [3H]thymidine uptake compared with untreated controls. In vitro analysis demonstrated a significant difference in the activity of five of the seven dinitroanilines between both life cycle stages of L. infantum. The amastigotes were 20-times more sensitive to chloralin and its isomer than to the dinitroanilines whereas the promastigotes were similar in sensitivity to the dinitroanilines and to chloralin and its isomer. This interesting finding suggests that the dinitroaniline precursors may have different target sites in the amastigotes to those within the promastigotes. Additionally, both chloralin and its isomer, and to a lesser extent benfluralin, caused a substantial stimulation of thymidine incorporation (up to 50%) at low concentrations. Dose response analysis suggests that the dinitroanilines may have more than one mode of action against L. infantum amastigotes and promastigotes. The inhibitory effects of the dinitroanilines against L. infantum vary from previous findings using the dinitroanilines against other Leishmania spp. The 348 base pair DNA sequence coding for beta-tubulin from amino acid residues 132 to 248 was obtained for L. infantum and used to compare the in vivo efficacy of albendazole with predicted activity based on beta-tubulin sequences of known benzimidazole sensitive protozoa. The use of beta-tubulin sequence as a predictive model of benzimidazole activity is discussed with particular reference to L. infantum.

The incidence of transient renal medullary hyperechogenicity in neonatal ultrasound examination.

A prospective ultrasound study of the urinary tracts of 85 neonates (64 term, 21 preterm) was performed to assess the incidence of transient renal medullary hyperechogenicity (RMH) in the first week of life. None of the neonates examined had evidence of renal dysfunction. Echogenic material was observed in the renal papillae/calyces, ureter, or bladder of 33 of the 64 term babies, but in the bladder of only one pre-term infant. The distribution of the echogenicity differs from that seen in medullary hyperechogenicity due to crystal deposition, suggesting that calyceal involvement is a common feature. Follow-up ultrasound scans at 10-14 days were possible in eight of the term neonates and demonstrated complete resolution of the RMH. The aetiology of transient neonatal RMH is unclear, although it may be related to protein cast deposition in the renal tubules. RMH may rarely be associated with transient renal dysfunction, but in healthy neonates should be recognized as a normal variant.

The ultrasound appearances of neonatal renal vein thrombosis.

Renal vein thrombosis (RVT) is the most frequently occurring vascular condition in the new-born kidney. The predisposing factors include dehydration, sepsis, birth asphyxia, maternal diabetes, polycythaemia and the presence of an indwelling umbilical venous catheter. (RVT) may present clinically with a flank mass, haematuria, hypertension or renal failure. Many imaging modalities have been employed, but ultrasound is the technique most commonly used in the evaluation of neonates with suspected RVT. Thrombosis commences in the small renal veins and subsequently propagates via larger interlobar veins to the main renal vein and inferior vena cava (IVC). The ultrasound appearances depend upon the stage at which the examination is performed and extent of the thrombus. Initially, the interlobular and interlobar thrombus appears as highly echogenic streaks. These streaks commence in a peripheral, focal segment of the involved kidney and only persist for a few days. In the first week the affected kidney swells and becomes echogenic with prominent echopoor medullary pyramids. Later, the swelling increases and the kidney becomes heterogenous with loss of corticomedullary differentiation. Grey scale ultrasound readily demonstrates thrombus within the renal vein and IVC. Adrenal haemorrhage is a recognized association and may be identified ultrasonically. Colour Doppler scanning provides additional information. In the early stages of RVT, colour Doppler may demonstrate absent intrarenal and renal venous flow. Ultimately, the kidney may recover, show focal scarring or become atrophic. Thus, ultrasound provides an accessible and reliable tool in the assessment of suspected neonatal RVT.

The use of pelvic ultrasound in female patients attending a GUM clinic.

This is a retrospective review of 279 pelvic ultrasound examinations requested over 19 months by a department of GU medicine. An abnormal ultrasound was rarely seen in women with pain but no pelvic mass (16%). If a mass was found on bimanual palpation, the yield of abnormal ultrasound was much higher (52%). Pelvic ultrasound was also useful in refuting a diagnosis of ectopic pregnancy by demonstrating an intrauterine gestational sac.

Towards measurement of outcome for patients with varicose veins.

OBJECTIVE: To develop a valid and reliable outcome measure for patients with varicose veins. DESIGN: Postal questionnaire survey of patients with varicose veins. SETTING: Surgical outpatient departments and training general practices in Grampian region. SUBJECTS: 373 patients, 287 of whom had just been referred to hospital for their varicose veins and 86 who had just consulted a general practitioner for this condition and, for comparison, a random sample of 900 members of the general population. MAIN MEASURES: Content validity, internal consistency, and criterion validity. RESULTS: 281(76%) patients (mean age 45.8; 76% female) and 542(60%) of the general population (mean age 47.9; 54% female) responded. The questionnaire had good internal consistency as measured by item-total correlations. Factor analysis identified four important health factors: pain and dysfunction, cosmetic appearance, extent of varicosity and complications. The validity of the questionnaire was demonstrated by a high correlation with the SF-36 health profile, which is a general measure of patients' health. The perceived health of patients with varicose veins, as measured by the SF-36, was significantly lower than that of the sample of the general population adjusted for age and a lower proportion of women. CONCLUSION: A clinically derived questionnaire can provide a valid and reliable tool to assess the perceived health of patients with varicose veins. IMPLICATIONS: The questionnaire may be used to justify surgical treatment of varicose veins.

Pain assessment tools: children's nurses' views.

The persistence of inadequate treatment of pain in children could be due to lack of knowledge and nurses' failure to assess and manage pain effectively. It is recognized that effective pain assessment leads to more satisfied children and families. This study explored children's nurses' views on the use of pain assessment tools in a tertiary referral centre. Almost two-thirds of nurses did not have a preference for a pain assessment tool, but nearly three-quarters of nurses surveyed agreed that the introduction of pain assessment tools would improve documentation. When nurses were asked how much time they needed for education on these tools, 83 percent wanted only two hours, although almost half stated lack of knowledge or education as the main obstacle to use of a pain assessment tool. The inconsistencies in these replies could reflect the conflicting demands between the nurses' need to increase their knowledge of pain assessment while managing a heavy workload.