Improving accuracy of quantifying nitrate removal performance and enhancing understanding of processes in woodchip bioreactors using high-frequency data.

Woodchip bioreactors have gained popularity in many countries as a conservation practice for reducing nitrate load to freshwater. However, current methods for assessing their performance may be inadequate when nitrate removal rates (RR) are determined from low-frequency (e.g., weekly) concurrent sampling at the inlet and outlet. We hypothesised that high-frequency monitoring data at multiple locations can help improve the accuracy of quantifying nitrate removal performance, enhance the understanding of processes occurring within a bioreactor, and therefore improve the design practice for bioreactors. Accordingly, the objectives of this study were to compare RRs calculated using high- and low-frequency sampling and assess the spatiotemporal variability of the nitrate removal within a bioreactor to unravel the processes occurring within a bioreactor. For two drainage seasons, we monitored nitrate concentrations at 21 locations on an hourly or two-hourly basis within a pilot-scale woodchip bioreactor in Tatuanui, New Zealand. A novel method was developed to account for the variable lag time between entry and exit of a parcel of sampled drainage water. Our results showed that this method not only enabled lag time to be accounted for but also helped quantify volumetric inefficiencies (e.g., dead zone) within the bioreactor. The average RR calculated using this method was significantly higher than the average RR calculated using conventional low-frequency methods. The average RRs of each of the quarter sections within the bioreactor were found to be different. 1-D transport modelling confirmed the effect of nitrate loading on the removal process as nitrate reduction followed Michaelis-Menten (MM) kinetics. These results demonstrate that high-frequency temporal and spatial monitoring of nitrate concentrations in the field allows improved description of bioreactor performance and better understanding of processes occurring within woodchip bioreactors. Thus, insights gained from this study can be used to optimise the design of future field bioreactors.

Reconstructing in-depth activity for chaotic 3D spatiotemporal excitable media models based on surface data.

Motivated by potential applications in cardiac research, we consider the task of reconstructing the dynamics within a spatiotemporal chaotic 3D excitable medium from partial observations at the surface. Three artificial neural network methods (a spatiotemporal convolutional long-short-term-memory, an autoencoder, and a diffusion model based on the U-Net architecture) are trained to predict the dynamics in deeper layers of a cube from observational data at the surface using data generated by the Barkley model on a 3D domain. The results show that despite the high-dimensional chaotic dynamics of this system, such cross-prediction is possible, but non-trivial and as expected, its quality decreases with increasing prediction depth.

The influence of unsaturated zone drainage status on denitrification and the redox succession in shallow groundwater.

Since nitrate is a major agricultural freshwater contaminant, denitrification is the environmentally most important step in the ecological succession of redox processes that can occur in groundwater. Understanding where and to what extent denitrification occurs would enable spatially differentiated land management and regulation. We investigated in a dairy farming catchment in the North Island of New Zealand the influence of the unsaturated zone's drainage status on the redox succession in shallow groundwater along a well transect spanning drainage conditions from well drained to very poorly drained. Groundwater samples were analysed for a variety of parameters including nitrate, tritium, dinitrogen, argon, methane and nitrous oxide. The redox classification based on measured redox-sensitive parameters broadly matched the a priori assessed drainage status of the overlying unsaturated zone. Only the groundwater underlying the well-drained soil was oxic and reflected the N losses from the intensive pastoral land use, with nitrate nitrogen concentrations up to 9.6 mg L-1. All other sites had mildly to strongly reduced groundwater and concomitantly decreasing or low nitrate concentrations, even at the water table. The tritium-derived mean residence time (MRT) estimates for the oxic groundwater (12 and 14 y) were within the range found in mildly reduced groundwater from the imperfectly drained sites (6-24 y), with the exception of one sample from below an aquitard (105 y). In contrast, the strongly reduced groundwater observed at the poorly and very poorly drained sites was relatively immobile (55 to >110 y). Denitrification was confirmed by the nitrate dual isotope signatures, and by the occurrence of excess dinitrogen, and likely occurred in both the unsaturated and saturated zones. A coherent sampling scheme throughout the unsaturated zone - saturated zone continuum should be used in future studies to allow ascertaining the exact location of denitrification activity in vertical profiles.

Vertical stratification of redox conditions, denitrification and recharge in shallow groundwater on a volcanic hillslope containing relict organic matter.

Natural denitrification in groundwater systems has been recognised as an ecosystem service that reduces the impact of agriculturally-derived nitrate inputs to surface waters. Identification of this ecosystem service within the landscape would permit spatially differentiated land management and legislation. However, spatial variation in groundwater redox conditions poses a significant challenge to such a concept. To gain understanding of the small-scale mosaic of biogeochemical and hydrological controls on denitrification, we established a well field consisting of 11 multilevel well (MLW) clusters on a hillslope containing relict organic matter buried by volcanic deposits 1.8 ka before present. Based on site-specific redox classification thresholds, vertical redox gradients and denitrification potentials were detected at 7 of the 11 sites. Palaeosols or woody debris, which had previously been identified in laboratory experiments as resident electron donors fuelling denitrification, were visually recognisable at 4 of the 7 MLW sites with vertical redox gradients. Moderately enhanced groundwater dissolved organic carbon (DOC) concentrations occurred where resident electron donors were evident. DOC concentrations were lower where anoxic and nitrate-depleted groundwater was found but with an absence of resident electron donors. In these instances, it was assumed that nitrate reduction had occurred somewhere upgradient of the sampled well screen along the lateral groundwater flow path, with the proximate electron donor (DOC) largely consumed in the process, since no evidence was found for denitrification being fuelled by inorganic electron donors. Due to high variability in the isotopic signature of nitrate in oxidised groundwater, the nitrate dual isotope method did not yield firm evidence for denitrification. However, realistic vertical patterns were obtained using the excess N2 method. Tritium-based age dating revealed that oxic conditions were restricted to young groundwater (mean residence time ≤ 3 y), while anoxic conditions were observed across a wider age range (3-25 y).

The impact of relict organic materials on the denitrification capacity in the unsaturated-saturated zone continuum of three volcanic profiles.

The denitrification capacity of wetlands, riparian zones, and aquifers in glacial outwash areas is well documented, but little or no information exists for volcanic profiles, particularly those containing relict organic matter contained in or on top of paleosols (old soils buried by volcanic deposits) below the groundwater table. Relict carbon contained in these layers could provide the necessary electrons to fuel heterotrophic denitrification. To the best of our knowledge, this is the first study investigating the denitrification capacity in both the unsaturated and saturated zone of volcanic profiles. Samples from three profile types with differing organic matter distribution were amended with N-enriched nitrate (NO-) and incubated in the laboratory under anaerobic conditions. Dinitrogen (N) dominated the N gas fluxes; averaged across all samples, it accounted for 96% of the total N (nitrous oxide [NO] and N) gas fluxes. Dinitrogen fluxes were generally highest in the A horizon samples (4.1-6.2 nmol N g h), but substantial fluxes were also observed in some paleosol layers (up to 0.72 nmol N g h). A significant correlation ( < 0.001) was found between the concentration of extractable dissolved organic carbon and the total N gas flux produced in samples from below the A horizon, suggesting that heterotrophic denitrification was the dominant NO attenuation process in this study. Extrapolation of lab-derived denitrification capacities to field conditions suggests that the denitrification capacity of profiles containing relict soil organic matter in the saturated zone exceeds the estimated N leaching from the root zone.

Aligning provider incentives to improve primary healthcare delivery in the United States.

BACKGROUND: The United States (US) is reforming primary care delivery systems, including the implementation of 'patient-centered medical homes.' Alignment of provider incentives with desired outcomes will likely be important to the success of these delivery system reforms. METHODS: This critical review uses a theoretical framework from game-theory models to discuss some of the dominant primary care provider payment models and how they create 'prisoner's dilemmas' that have stalled past reform efforts. It then uses this framework to illustrate, hypothetically, how advantages from different models could be blended together to encourage cooperation and improve the quality of primary care services delivered, thus providing an escape from current prisoner's dilemmas faced by providers. FINDINGS: Improvements in primary care delivery will largely hinge on blended payment mechanisms that can effectively combine the advantageous elements of fee-for-service, capitation, and incentive payments into a balanced equation that enables providers to escape the perverse financial incentives of current payment mechanisms and overcome collective action problems. CONCLUSIONS: If balanced appropriately, a blend of guaranteed payment and selective incentives designed to encourage primary care providers to deliver high quality care, efficient and equitable care and to eliminate incentives towards over-servicing could reach outcomes leading to shared benefits for everyone involved.

Ultrasound screening strategies for the diagnosis of congenital anomalies of the kidney and urinary tract.

PURPOSE: Congenital anomalies of the kidneys and urinary tract (CAKUT) are among the most common anomalies in newborn infants, and may cause chronic renal disease in newborns. We investigated the sensitivity and specificity of different ultrasound-based screening strategies for CAKUT. MATERIALS AND METHODS: Newborns (n = 4331) were analyzed for CAKUT in at least one ultrasound examination as a part of the Survey of Neonates in Pomerania (SNiP), a 7-year population-based study on neonates in Western Pomerania (Germany). Intrauterine ultrasound examinations were compared with early postnatal ultrasound findings (from days 3 - 7 of life) and pathological findings within the first 6 months of postnatal life. RESULTS: Cases of CAKUT were detected in 309 (3.7 %) kidneys in one ultrasound examination at the following points of time at least: (i) prenatally in 56 newborns (18.2 %), (ii) 3 - 7 days postnatally in 201 newborns (65.2 %) and (iii) in 52 newborns (17 %) during the 6-month follow-up. The prevalence was significantly higher in male infants, and hydronephrosis was found to be the most frequent obstructive nephropathy (83.3 %). Significant co-morbidity was observed with CNS malformations. The diagnostic sensitivity was significantly higher in postnatal ultrasound screening (79.6 vs. 18.2 % prenatally), while the specificity was above 99 % at all time points. CONCLUSION: This study demonstrates a high prevalence of CAKUT and demonstrates the importance of combined prenatal and postnatal ultrasound examinations for early CAKUT diagnosis.

[Correlation between sex, intrauterine position and familial predisposition and neonatal hip ultrasound results]. / Populationsbasierte Studie zu Prädispositionsfaktoren und Häufigkeit der Hüftgelenksdysplasie.

AIM: To correlate findings of hip ultrasound on day 4-10 of life with sex, intrauterine position and a positive family history for congenital hip anomalies. METHODS: The SNiP-study ( Survey of Neonates In Pommerania) registered 2256 neonates (2030 term, 226 preterm) between May 2002 and March 2004. Hip ultrasound results of 1043 term and since October 2003 33 preterm neonates were analysed. Time of ultrasound was day 4-10 after birth. Preterm neonates were examined when reaching their corrected term gestational age. Ultrasound was applied with a 7.5 MHz linear scanner and results were classified according to Graf. Chi-square and Fishers exact test were used for statistical analysis. RESULTS: 4.9 % of the screened hips were classified as IIc or higher, 3.1 % were unilateral and 1.7 % bilateral. Incidence was significantly higher (p < 0.023) in females (6.6 %) than in males (3.2 %). There was no significant difference in intrauterine position or positive family history for hip anomalies with 3.7 % for mothers, 1.2 % of fathers and 2.4 % of siblings positive. There was a higher incidence for congenital hip dysplasia in preterms with 6.1 %, which is not significant due to the limited number. DISCUSSION: Current screening methods miss up to 18 % of newborns with severe hip dysplasia. We were able to demonstrate that screening for congenital hip dysplasia with ultrasound is a diagnostic tool even during the first days of life. There is a significantly higher incidence of congenital hip dysplasia in females, but in contrast to other studies we found no significant difference in intrauterine position or familial history. Earlier diagnosis and therapy on the base of relevant risk factors might correspond with an improved prognosis and outcome. Further studies are warranted to evaluate the significance in preterm neonates.

[Cavernoma of the medulla oblongata mimicking "Anorexia nervosa" - a case report]. / Kavernom der Medulla oblongata unter dem Bild einer "Anorexia nervosa".

An 11-year-old girl presented with recurrent vomiting, reduced food and fluid intake, weight loss and dizziness. In an external hospital she was diagnosed as having habitual vomiting and a beginning eating disorder. The physical examination revealed a very thin, malnourished child with abdominal pain on palpation but without neurologic deficits. Laboratory findings, X-rays, endoscopy and ultrasound revealed no pathological results either. Since the EEG and the cranial computed tomography (CT) were normal, we also suspected the beginning of an eating disorder especially due to some psychical peculiarities. The MRI which was done for ultimate exclusion of an infratentorial tumor showed a well defined displacing structure in the dorsal medulla oblongata and in the upper cervical spinal cord. A corresponding prolongation of the central conduction time was found in the median nerve SSEP whereas the BAEPs were normal. The tumor was excised in toto and the histological examination confirmed the suspected diagnosis of cavernous hemangioma (cavernoma). The post operative phase was without any complications and the intiated nutrition was well tolerated. Neurological deficits were not observed.

Lack of sex difference in cerebrospinal fluid (CSF) leptin levels and contribution of CSF/plasma ratios to variations in body mass index in children.

In adults, leptin seems to cross the blood-brain barrier by a saturable transporter. This may contribute to the development of obesity. The present study in healthy children investigates leptin levels in plasma and cerebrospinal fluid (CSF) in relation to body constitution. This prospective study analyzed leptin levels in plasma and CSF samples (stored at -80 C) of patients without CNS infection or blood-brain barrier dysfunction. Inclusion criteria included temperature less than 38.5 C, C-reactive protein levels below 10 mg/L, CSF leukocyte levels less than 10(7)/L, no need for neurosurgical or oncological treatment, and no history of trauma. Four groups were designated according to body mass index. Sixty-five children (28 girls and 37 boys) entered the study. Plasma leptin (median) was 7.4 in girls and 2.6 ng/mL in boys., CSF leptin was 0.273 and 0.204 ng/mL, respectively, leading to CSF/plasma ratios of 0.045 and 0.071, respectively. Ratios were clearly dependent on body mass index percentiles (r = -0.484; P < 0.01, significant differences between groups by ANOVA). Median plasma leptin levels in the 4 groups (body mass index, <10th, 10th-50th, 50th-90th, and >90th percentile) were 2.0, 2.3, 4.1, and 8.8 ng/mL; CSF/plasma ratios were inversely related: 8.2%, 7.6%, 5.5% and 3.6%. In healthy children, CSF leptin levels account for approximately 5% of plasma levels. CSF/plasma ratios in girls are lower than those in boys, explaining why calorie intake and energy expenditure are not grossly different despite large differences in circulating plasma leptin concentrations. CSF/plasma ratios of lean children are higher than those in obese children. The dynamic changes in the CSF/plasma ratios are more pronounced in lean children, i.e. the nonlinear transport characteristics of the leptin system amplifies the information about changes in body energy stores in this population, indicating that leptin is part of a mechanism to protect the body from critical weight loss rather than to avoid obesity.

pp60(v-src) induction of cyclin D1 requires collaborative interactions between the extracellular signal-regulated kinase, p38, and Jun kinase pathways. A role for cAMP response element-binding protein and activating transcription factor-2 in pp60(v-src) signaling in breast cancer cells.

The cyclin D1 gene is overexpressed in breast tumors and encodes a regulatory subunit of cyclin-dependent kinases that phosphorylate the retinoblastoma protein. pp60(c-src) activity is frequently increased in breast tumors; however, the mechanisms governing pp60(c-src) regulation of the cell cycle in breast epithelium are poorly understood. In these studies, pp60(v-src) induced cyclin D1 protein levels and promoter activity (48-fold) in MCF7 cells. Cyclin D1-associated kinase activity and protein levels were increased in mammary tumors from murine mammary tumor virus-pp60(c-src527F) transgenic mice. Optimal induction of cyclin D1 by pp60(v-src) involved the extracellular signal-regulated kinase, p38, and c-Jun N-terminal kinase members of the mitogen-activated protein kinase family. Cyclin D1 promoter activation by pp60(v-src) involved a cAMP response element-binding protein (CREB)/activating transcription factor 2 (ATF-2) binding site. Dominant negative mutants of CREB and ATF-2 but not c-Jun inhibited pp60(v-src) induction of cyclin D1. pp60(v-src) induction of CREB was blocked by the p38 inhibitor SB203580 or by mutation of CREB at Ser133. pp60(v-src) induction of ATF-2 was abolished by the c-Jun N-terminal kinase inhibitor JNK-interacting protein-1 or by mutation of ATF-2 at Thr69 and Thr71. CREB and ATF-2, which bind to a common pp60(v-src) response element, are transcriptionally activated by distinct mitogen-activated protein kinases. Induction of cyclin D1 activity by pp60(v-src) may contribute to breast tumorigenesis through phosphorylation and inactivation of the retinoblastoma protein.

[Prepontine epidural hemorrhage]. / Präpontine epidurale Blutung.

Extradural haematomas of the clivus represent a rare event and occur almost only in infancy. The case of a haematoma promptly operated upon via a transdural cerebellopontine angle approach is described for the first time. The mechanism of injury is discussed.

Serum eosinophil cationic protein measurements in the management of perennial and periodic asthma: a prospective study.

We performed a prospective study in order: 1) to determine whether a correlation could be found between serum eosinophil cationic protein (ECP) levels and clinical and functional status in perennial asthmatics during a 5 month prospective study; and 2) to evaluate the relationship between allergic exposure and ECP levels in periodic asthmatics. Two groups of asthmatic patients were selected: a group of acutely ill perennial asthmatics and a group of periodic asthmatics. The acutely ill perennial asthmatics (n=22, mean age=39.4 yrs) were included on the basis of hospitalization for acute asthma. At the end of the hospitalization, there was a 5 month follow-up of clinical, functional and medication scores, as well as eosinophil counts and ECP levels. The periodic asthmatic group was composed of asthmatics sensitized to birch and tree pollens (n=10, mean age=33.8 yrs). The same measurement were performed on this group, before, during and after the pollen season. Under corticosteroid treatment in the acutely ill patients, there was a significant decrease in serum ECP levels between the first day of hospitalization and the day of discharge (mean: 23.2 microg x L(-1) and 9.5 microg x L(-1), respectively; p=0.006). No correlation was found between the clinical status, functional status and serum ECP levels during the 5 month follow-up. A significant increase in ECP levels was found in periodic asthmatics during the pollen season. Our results suggest that serum eosinophil cationic protein is a useful marker of allergen exposure and of acute asthma treatment. This could be of importance in the prevention and follow-up of allergic asthma; the value of serum eosinophil cationic protein measurements in the day-to-day management of adult asthmatics needs to be further clarified.

Maffucci's syndrome as cause of chronic liquorrhea.

We present the case of a 14-year-old girl suffering from Maffucci's syndrome, a rare ailment belonging to the group of osteochondrodysplasias. At the age of 6 months, a diffuse swelling first appeared in the girl's right cheekbone region and the periauricular area. Because of recurrent meningitis with massive otoliquorrhea, several surgical revisions were performed, beginning at the age of 4 years. The histological and immunohistochemical diagnosis showed hemangioma and lymphangioma with enchondroma. As a peculiarity of our patient's diagnosis, we found multiple bone defects apparently caused by venous and lymphomatous angiomatosis. There was also enchondromatosis of the skull base and the upper cervical vertebrae, which caused the recurrent otoliquorrhea and rhinoliquorrhea. A fistula closure was undertaken through a retromastoidal, suboccipital approach and fascial graft of the posterior cranial fossa.

The diagnostic importance of eosinophil granulocytes in the CSF of children with ventricular-peritoneal shunt systems.

We investigated the occurrence of cerebrospinal fluid (CSF) eosinophilia in patients with ventriculo-abdominal shunt systems with regard to possible infection. For this purpose, we examined the CSF of 83 children at the time of shunt obstruction or malfunction. In 32 children (38.6%) we found more than 4% of eosinophil granulocytes in the CSF with a maximum of 76%. In 15 of these 32 children the CSF was sterile, whereas in 17 patients bacterial infection was present. In the CSF of 16 of those 17 children, Staph. epidermidis was cultivated. There was statistically significant correlation between positive Staph. epidermidis culture and the occurrence of CSF eosinophilia (P<0.05). The occurrence of CSF eosinophilia in patients with ventriculo-peritoneal shunts is well known and was mostly attributed to an allergic reaction. Our findings support the theory of an infectious etiology of the eosinophilia and are thus in line with new American and French studies. We believe that CSF eosinophilia indicates a persistent infection of the central nervous system by the contaminated shunt system. As the organism which is the most common cause we cultured Staph. epidermidis.