Impacts of conversion from forestry to pasture on soil physical properties of Vitrands (Pumice Soils) in the Central North Island, New Zealand

Abstract At least 30 000 hectares of land has been converted from plantation forest to pasture in the central North Island of New Zealand between 2000 and 2010. When forests are cleared for pasture the soil may undergo changes in soil structure affecting physical properties. The overall objective of this study was to investigate changes in soil physical properties in Pumice Soils following land use change from forest to pasture. Two study areas were identified; one near Tokoroa (Maxwell Farms), and one near Taupo (Wairakei Estate). At each study area a series of sites including: plantation pine forest, pasture converted from pine forest 2,3,4 and 5 years ago, and long term (>50 years) dairy, and sheep and beef pasture, were identified, all on Taupo Pumice Soil. Field and laboratory methods included measurement of; penetration resistance, degree of packing, soil dry bulk density, soil hydrophobicity, unsaturated and saturated hydraulic conductivity, soil moisture retention, aggregate stability, particle size distribution, and soil pH. There was increased soil compaction in the A horizon on recently converted sites compared to pine forest sites as evidenced by higher soil dry bulk density, increased penetration resistance, and degree of packing. At the Tokoroa study area the pine forest soil A horizon had a significantly lower dry bulk density ( mean 0.58 g/cm3) ( P < 0.05 ) than any of the pasture sites (mean 0.65 - 0.72 g/cm3). At the Taupo study area only long term dairy (mean 0.78 g/cm3) and the youngest pasture site (3 years since conversion from pine forest) (mean 0.74 g/cm3) had higher (P < 0.05) bulk density than the plantation pine forest soil. At the Tokoroa study area, the penetration resistance and degree of packing in the A horizon of the pine forest site was lower ( P< 0.01 ) than any other site. The degree of packing and penetration resistance at the Taupo study area in the A horizon of the pine forest site was lower ( P< 0.05 ) compared to 3 years old conversion and long term dairy pasture but was not significantly different from pastures converted 4 and 5 years ago. The water repellency of recently converted pastures was higher (P < 0.05) than pine forest at both study areas. Two of the three long-term pasture sites investigated had very low water repellency. The long term pasture sites had markedly higher total available water holding capacity than either the recently converted pastures or the pine forest sites. The pine forest soil water content at 10 kPa (field capacity) and 100 kPa (readily available water) was generally lower than pasture sites. At the Tokoroa study area there was no significant difference in unsaturated hydraulic conductivity between the pine forest soil and any other site. At Taupo the pine forest soil unsaturated hydraulic conductivity was higher (P < 0.05) than the most recent conversion site (3 years old) but not significantly different from other sites. At the Taupo study area none of the land uses had significantly different saturated infiltration rate compared to the pine forest. At the Tokoroa study area the pine forest saturated hydraulic conductivity was higher (P < 0.05) than the 5 years old conversion or the long term sheep and beef farm. The A horizon, at both study areas, was observed to be deepest under long term dairy farm followed by forest and shallowest on sites recently converted from pine plantation. There was no clear pattern of changes in soil colour, pedality or boundary distinctiveness and shape, between different sites. Aggregate stability of the Ap horizon was noticeably lower in recently converted pastures than in the pine forest or long term pasture sites. Soil pH values were generally in 4.5 to 5.9 ranges across all land uses in all horizons. The exception was the most recent conversions to pasture (2 and 3 years ago converted) at the Tokoroa study area which exceeded pH 6, presumably due to high rates (3.5 T/ha) of lime application during the conversion process

PREDICTORS OF CAROTID INTIMA MEDIA THICKNESS IN OBESE ADOLESCENTS

Our aim was to assess cardiovascular risk factors that may predict increased carotid intima media thickness (cIMT) in obese children and adolescents. Children and adolescents were included in the cross-sectional study if they were aged 9-19 years and had primary obesity. Besides anthropometric and biochemical measurements, ambulatory blood pressure monitoring, measurement of carotid intima media thickness and exercise stress test were performed. We included 103 obese patients and divided them according to the ambulatory blood pressure findings in two groups: obese patients with and without ambulatory hypertension. There were 49 obese patients with and 54 without ambulatory hypertension Univariate analysis showed that there was a significant positive correlation of cIMT with age (r = 0.334, p= 0.001), body mass index (r = 0.288, p = 0.004), waist circumference (r = 0.352, p = 0.000), hip circumference (r = 0.288, p = 0.004), night-time systolic blood pressure (r = 0.226, p = 0.027), and peak diastolic blood pressure on exercise test (r = 0.241, p = 0.018). In a stepwise model, age, waist circumference and peak diastolic blood pressure on exercise test were independent predictors of cIMT

Phase IIa Global Study Evaluating Rituximab for the Treatment of Pediatric Patients With Granulomatosis With Polyangiitis or Microscopic Polyangiitis

OBJECTIVE: To assess the safety, tolerability, pharmacokinetics, and efficacy of rituximab (RTX) in pediatric patients with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA). METHODS: The Pediatric Polyangiitis Rituximab Study was a phase IIa, international, open-label, single-arm study. During the initial 6-month remission-induction phase, patients received intravenous infusions of RTX (375 mg/m2 body surface area) and glucocorticoids once per week for 4 weeks. During the follow-up period, patients could receive further treatment, including RTX, for GPA or MPA. The safety, pharmacokinetics, pharmacodynamics, and exploratory efficacy outcomes with RTX were evaluated. RESULTS: Twenty-five pediatric patients with new-onset or relapsing disease were enrolled at 11 centers (19 with GPA [76%] and 6 with MPA [24%]). The median age was 14 years (range 6-17 years). All patients completed the remission-induction phase. During the overall study period (≤4.5 years), patients received between 4 and 28 infusions of RTX. All patients experienced ≥1 adverse event (AE), mostly grade 1 or grade 2 primarily infusion-related reactions. Seven patients experienced 10 serious AEs, and 17 patients experienced 31 infection-related AEs. No deaths were reported. RTX clearance correlated with body surface area. The body surface area-adjusted RTX dosing regimen resulted in similar exposure in both pediatric and adult patients with GPA or MPA. Remission, according to the Pediatric Vasculitis Activity Score, was achieved in 56%, 92%, and 100% of patients by months 6, 12, and 18, respectively. CONCLUSION: In pediatric patients with GPA or MPA, RTX is well tolerated and effective, with an overall safety profile comparable to that observed in adult patients with GPA or MPA who receive treatment with RTX. RTX is associated with a positive risk/benefit profile in pediatric patients with active GPA or MPA

Discontinuation of RAAS Inhibition in Children with Advanced CKD

Background and objectives Although renin-angiotensin-aldosterone system inhibition (RAASi) is a cornerstone in the treatment of children with CKD, it is sometimes discontinued when kidney function declines. We studied the reasons of RAASi discontinuation and associations between RAASi discontinuation and important risk markers of CKD progression and on eGFR decline in the Cardiovascular Comorbidity in Children with CKD study. Design, setting, participants,& measurements In this study, 69 children with CKD(67% male, mean age 13.7 years, mean eGFR 27 ml/min per 1.73m(2)) who discontinued RAASi during prospective follow-up were included. Initial change in BP, albuminuria, and potassium after discontinuation were assessed (median time 6 months). Rate of eGFR decline (eGFR slope) during a median of 1.9 years before and 1.2 years after discontinuation were estimated using linear mixed effects modeling. Results Physician-reported reasons for RAASi discontinuation were increase in serum creatinine, hyperkalemia, and symptomatic hypotension. After discontinuation of RAASi, BP and albuminuria increased, whereas potassium decreased. eGFR declined more rapidly after discontinuation of RAASi (23.9 ml/min per 1.73m2 per year; 95% confidence interval, 25.1 to 22.6) compared with the slope during RAASi treatment (21.5 ml/min per 1.73 m(2) per year; 95% confidence interval, 22.4 to 20.6; P=0.005). In contrast, no change in eGFR slope was observed in a matched control cohort of patients in whom RAASi was continued. Conclusions Discontinuation of RAASi in children with CKD is associated with an acceleration of kidney function decline, even in advanced CKD

Long-term renal outcome in children with OCRL mutations: retrospective analysis of a large international cohort

BACKGROUND: Lowe syndrome (LS) and Dent-2 disease (DD2) are disorders associated with mutations in the OCRL gene and characterized by progressive chronic kidney disease (CKD). Here, we aimed to investigate the long-term renal outcome and identify potential determinants of CKD and its progression in children with these tubulopathies. METHODS: Retrospective analyses were conducted of clinical and genetic data in a cohort of 106 boys (LS: 88 and DD2: 18). For genotype-phenotype analysis, we grouped mutations according to their type and localization. To investigate progression of CKD we used survival analysis by Kaplan-Meier method using stage 3 CKD as the end-point. RESULTS: Median estimated glomerular filtration rate (eGFR) was lower in the LS group compared with DD2 (58.8 versus 87.4 mL/min/1.73 m(2), P < 0.01). CKD stage II-V was found in 82% of patients, of these 58% and 28% had moderate-to-severe CKD in LS and DD2, respectively. Three patients (3%), all with LS, developed stage 5 of CKD. Survival analysis showed that LS was also associated with a faster CKD progression than DD2 (P < 0.01). On multivariate analysis, eGFR was dependent only on age (b = -0.46, P < 0.001). Localization, but not type of mutations, tended to correlate with eGFR. There was also no significant association between presence of nephrocalcinosis, hypercalciuria, proteinuria and number of adverse clinical events and CKD. CONCLUSIONS: CKD is commonly found in children with OCRL mutations. CKD progression was strongly related to the underlying diagnosis but did not associate with clinical parameters, such as nephrocalcinosis or proteinuria

Interactive Surfaces Based on Polymer Brushes

While the bulk structure of a material determines its mechanical properties, its surface plays a key role when interactions with the environment are important. Nowadays materials in bio- and nanotechnology are required to possess very complex functionalities and to interact specifically to the stimuli they receive from their surroundings. Thus, their surface modifications are becoming very demanding. In recent years surface initiated controlled radical polymerization techniques have emerged as very versatile strategies that provide a powerful toolbox to tackle the challenges that are set to material scientists. The attractiveness of these methods lies in the possibility to create well defined surface arrangements of polymer chains, which we refer to as polymer brushes, with precise control over thickness, composition and architecture. In addition, these techniques can be applied to very challenging substrates with respect to the chemical composition and geometry, which also includes porous materials. This Thesis, therefore, exploits the possibilities that surface-initiated controlled radical polymerization techniques offer to finely tune interfacial properties of materials and render them capable to interact with chemical and biological species in a desired way. Its paramount aim is to demonstrate how the functionalities and geometry of a polymer brush matrix can be employed to influence inorganic film deposition using synthetic, biomimetic and purely biological mechanism or enhance polymer brushed stability in aqueous media. This Thesis is divided into five distinct chapters, which will be briefly summarized in following paragraphs. Chapter 1 describes the preparation of polymer brushes and strategies that are used to control their chemical composition and architecture. Additionally, it will give an overview on the use of brushes as cell adhesive surfaces as well as templates for the production of nanoparticles and thin inorganic films. Chapter 2 explores a new strategy to guide the chemical solution deposition of thin, microstructured metal films. The proposed strategy is based on the use of poly(2-(methacryloyloxy)ethyl ammonium chloride) (PMETAC) brushes grown via surface-initiated atom transfer radical polymerization as a template. Thin films are prepared by first loading the PMETAC brushes with an appropriate precursor, followed by its reduction by NaBH4 and finally an oxygen plasma treatment to remove the stabilizing polymer brush matrix and generate the desired thin metallic film. Of particular interest is the question whether the thickness and lateral dimensions of the deposited metallic films can be controlled by micropatterning the polymer brush template and varying the brush thickness. In addition, this concept will be extended to the preparation of bimetallic (gold/palladium) films using a single polymer brush matrix. A similar strategy is explored in Chapter 3 to control the deposition of thin calcium carbonate films using a biomimetic process. The process is characterized by the stabilization of amorphous calcium carbonate, the geometry and localication of which can be controlled by the poly(methacrylic acid) brush template. A special focus of this Chapter is to examine the influence of the polymer brush thickness on the mineral deposition and to determine to which extent is the mineral phase is integrated into the polymer brush film. The aim of Chapter 4 is to develop a general approach for the modification of implantable materials with a polymer brush based coating that promotes bone formation. The proposed coatings are prepared via surface-initiated copolymerization of 2-hydoxyethyl methacrylate and 2-(methacryloyl)ethyl phosphate, which results in a thin hydrogel layer that mimics the negatively charged matrix macromolecules involved in natural bone formation. To further emulate the properties of the natural bone extracellular matrix, the coatings will be functionalized with the cell adhesive GGGRGDS peptide. The ability of the proposed coatings to induce bone formation is investigated in in vitro experiments on MC3T3-E1 pre-osteoblasts and evaluated using an ALP and alizarin red assays. Finally, Chapter 5 focuses on studying the parameters that could prevent the hydrolytic cleavage of Si-O bond, which tethers the polymer brushes grafted from SiOx in aqueous media. In the first part of the study, the length of the organosilane initiator's alkyl spacer will be varied, in order to evaluate to which extent it can insulate the site that anchors the hydrophilic polymer brush to the substrate. In the second part, a short, hydrophobic block will be introduced between the silicon oxide substrate and the hydrophilic polymer in order to more efficiently protect the underlying Si-O bond from the surrounding aqueous media and prevent the chain detachment

Identification of The Low Frequency Dynamic Behavior of Surrogate Explosive Materials

The mechanical response of energetic materials, especially those used in improvised explosive devices and munitions, is of great interest in the defense community. The safe deployment of munitions in environments exposed to high levels of vibration requires an understanding of materials behavior under these conditions. The goal of this work is to characterize the mechanical material behavior of the energetic materials by developing robust models of low frequency uniaxial behavior. This is achieved by conducting low frequency harmonic and random base excitation tests on a mass-material system at various levels of excitation. Then, a two-stage system identification methodology developed in this research is used to determine system model structure and to estimate system parameters from which energetic material parameters (stiffness, damping and viscoelastic properties) can be extracted. Eight different model structures were chosen with varying stiffness, damping and viscoelastic terms to describe the mass-material system dynamic response. The stiffness and damping terms are estimated by using a continuous time system identification approach and a Prony analysis estimation technique is used to estimate the viscoelastic terms. The inclusion of a hysteretic damping term alongside a viscoelastic term improved the prediction of the response in the region of the mass-material system resonance. The Young\u27s Modulus was estimated from linear approximations to the stiffness terms for the pure binder sample and the crystal solid-loaded sample. The system identification approach that has been developed can also be applied to identify models for other viscoelastic materials, such as foams and rubber-like materials

Sprachenvielfalt in der EU

Die Sprachenvielfalt in der EU kann im Rahmen der intekulturellen Kommunikation als Lösung zum Problem des Kulturschocks gedeutet werden. Die Bemühungen seitens der EU-Institutionen die bestehenden Sprachen auf ihrem Gebiet zu wahren und gleichzeitig die Mehrsprachigkeit fördernden Maßnahmen spielen eine große Rolle bei der Sprachenpolitik

Characterization and modeling of materials used in improvised explosive devices

The mechanical response of energetic materials, especially those used in improvised explosive devices, is of great interest in the defense community. By understanding the mechanical behavior of the explosive material, it is believed that a remote acoustic or electromagnetic excitation may be tuned to produce signature that can be used to indicate the presence of explosives. The goals of the investigation were to identify macroscopic uni-axial mechanical material properties, and to develop robust models of uni-axial behavior of polymer energetic materials. Attention was restricted to uni-axial deformation of hydroxyl-terminated polybutadiene (HTPB) binder embedded with ammonium chloride crystals (NH4Cl). An elastic Ogden model was fitted to stress-strain data from uni-axial compression tests conducted on the HTPB binder. From the low-strain compression test data estimates of the Young\u27s Modulus of the binder matrix where found to range from 2.67 MPa to 7.56 MPa. A series of swept sine-wave base-excitation tests were conducted on 0% and 50% crystal/binder volume fraction materials attached to a mass to examine the behavior and repeatability of the material-mass system dynamic responses. A continuous-time system identification approach is applied to develop models that predicted the harmonic base excitation responses. The estimated models were analyzed to produce estimates of the material properties. Six different models containing different combinations of linear and nonlinear expressions of stiffness, damping and viscoelastic terms were considered. While good agreement between the response measured in experiments and responses predicted from a linear model without viscoelasticity were often obtained, the inclusion of a hereditary viscoelastic term significantly improved the results. Some improvements were achieved when using a nonlinear viscoelastic model for the 50% material. Estimates of the damping ratio ranged from 0.10 to 0.13 for the 0% material and from 0.20 to 0.22 for the 50% material. Lastly, the Young\u27s Modulus (E), was estimated from linear approximations to the stiffness terms in the equation of motion; for HTPB 0%, Young\u27s Modulus ranges from 3.307 MPa to 7.251 MPa, and for HTPB 50%, Young\u27s Modulus ranges from 29.63 MPa to 66.29 MPa. The Young\u27s Modulus estimates of the HTPB binder matrix are of the same order and range as the estimated from the room-temperature compression tests