Midpalatal implants vs headgear for orthodontic anchorage - a randomized clinical trial: Cephalometric results

OBJECTIVE: To compare the clinical effectiveness of the mid-palatal implant as a method of reinforcing anchorage during orthodontic treatment with that of conventional extra-oral anchorage. DESIGN: A prospective, randomized, clinical trial Setting: Chesterfield and North Derbyshire Royal Hospital NHS Trust and the Charles Clifford Dental Hospital, Sheffield. SUBJECTS AND METHODS: 51 orthodontic patients between the ages of 12 and 39, with a class II division 1 malocclusion and ‘absolute anchorage’ requirements were randomly allocated to either receive a mid-palatal implant or headgear to reinforce orthodontic anchorage. The main outcome of the trial was to compare the mesial movement of the molars and incisors of the two treatment groups between T1 (start) and T2 (end of anchorage reinforcement) as measured from cephalometric radiographs. RESULTS: The reproducibility of the measuring technique was acceptable. There were significant differences between the T1 and T2 measurements within the implant group for the position of the maxillary central incisor (p<0.001), position of the maxillary molar (p=0.009) and position of the mandibular molar (p<0.001). There were significant differences within the headgear group for the position of the mandibular central incisor (p<0.045), position of the maxillary molar (p=<0.001) and position of the mandibular molar (p<0.001). All the skeletal and dental points moved mesially more in the headgear group during treatment than in the implant group. These ranged from an average of 0.5mm more mesial for the mandibular permanent molar to 1.5mm more mesial for the maxillary molar and mandibular base. None of the treatment changes between the implant and headgear groups were statistically significant. CONCLUSIONS: Mid-palatal implants are an acceptable technique for reinforcing anchorage in the orthodontic patient

Midpalatal implants vs headgear for orthodontic anchorage - a randomized clinical trial: Cephalometric results

OBJECTIVE: To compare the clinical effectiveness of the mid-palatal implant as a method of reinforcing anchorage during orthodontic treatment with that of conventional extra-oral anchorage. DESIGN: A prospective, randomized, clinical trial Setting: Chesterfield and North Derbyshire Royal Hospital NHS Trust and the Charles Clifford Dental Hospital, Sheffield. SUBJECTS AND METHODS: 51 orthodontic patients between the ages of 12 and 39, with a class II division 1 malocclusion and ‘absolute anchorage’ requirements were randomly allocated to either receive a mid-palatal implant or headgear to reinforce orthodontic anchorage. The main outcome of the trial was to compare the mesial movement of the molars and incisors of the two treatment groups between T1 (start) and T2 (end of anchorage reinforcement) as measured from cephalometric radiographs. RESULTS: The reproducibility of the measuring technique was acceptable. There were significant differences between the T1 and T2 measurements within the implant group for the position of the maxillary central incisor (p<0.001), position of the maxillary molar (p=0.009) and position of the mandibular molar (p<0.001). There were significant differences within the headgear group for the position of the mandibular central incisor (p<0.045), position of the maxillary molar (p=<0.001) and position of the mandibular molar (p<0.001). All the skeletal and dental points moved mesially more in the headgear group during treatment than in the implant group. These ranged from an average of 0.5mm more mesial for the mandibular permanent molar to 1.5mm more mesial for the maxillary molar and mandibular base. None of the treatment changes between the implant and headgear groups were statistically significant. CONCLUSIONS: Mid-palatal implants are an acceptable technique for reinforcing anchorage in the orthodontic patient

Evaluation of nitrogen use efficiency at various soil depths as measured by canola and wheat growth

Non-Peer ReviewedA growth chamber experiment was conducted in columns to determine the availability of soil nitrogen at various depths to canola and wheat plants. Seven treatments under wet and dry watering regimes were imposed: 0-15, 15-30, 30-45, and 45-60 cm layers enriched with 15 ug g-1 (30 kg ha-1) of N and 0-30, 15-45, and 30-60 cm layers enriched with 7.5 ug g-1 (30 kg ha-1) of N (both rates as NH4NO3). Non significant differences in plant, seed, and straw mass values were observed among treatments in the irrigated wheat and canola experiments. Also, no trend in soil NO3 removal was established for the soil layers sampled at harvest for these experiments. Variability within the treatments and/or lack of nitrogen response may have masked slight yield differences imposed by the N treatments. This variability may have been imposed from differences in the amount of leachate from the columns in the irrigated experiments. The dryland wheat experiment showed significant plant and seed mass responses to N enrichment treatments. The dryland canola experiment showed significant seed yield increases to the N enrichment amendments. In both the dryland wheat and canola experiments, soil NO3 levels were very low in the 0-30 cm soil layer. This was attributed to plant removal of N from the upper soil horizons. Less variability in plant, seed, and straw mass values was observed in the dryland experiments because no leachate was collected from the soil columns

Soil fertility issues

Non-Peer ReviewedIn 1991, the Saskatchewan soil testing laboratory established programs to address some of the concerns and questions raised by producers. With the cooperation of fertilizer dealers, the lab established 12 strip trials on various fields involving yield responses to various fertilizer treatments. Fertilization with copper, boron, sulfur, phosphorus, potassium, and chloride was evaluated on one or more of the following crops: canola, wheat, alfalfa, and barley

Handling of soil samples prior to testing

Non-Peer Reviewe

A 25-year review of fertilizer consumption and plant nutrient removal in the prairie provinces

Non-Peer ReviewedNutrient removal I replacement ratios were calculated in Manitoba, Saskatchewan, and Alberta from 1965 to 1989 by dividing total fertilizer (N, P, and K) sales by the total crop removal of plant nutrients. The nutrient removal I replacement ratios revealed that significant depletions of soil reserves of N, P, and K have taken place over the past 25 years. The average negative balance of N, P2O5, and K2O on the prairies is estimated at 640, 125, and 490 thousand tonnes. Even with the substantial increase in the use of fertilizers in the past five years compared to the 25 year average, the nutrient deficit continues to be unacceptably high for nitrogen (485,000 tonnes), only modest for phosphorus (86,000 tonnes), and as could be expected for potassium, has increased significantly to 570,000 tonnes. Overall, the calculations suggest that Manitoba is very close to nitrogen and phosphorus balance. Alberta has a relatively close balance, while Saskatchewan has not only experienced an unacceptably high N and P deficit for the past 25 years, but continues to do so at the present time

Evaluation of Penicillium bilaji inoculation and copper and zinc fertilization in relation to crop yield and nutrient uptake

Non-Peer ReviewedGrowth chamber and field experiments were conducted on three low micronutrient alkaline soils from Northeastern Saskatchewan to test the efficacy of PB-50 inoculation and phosphorus (P), copper (Cu) and zinc (Zn) fertilization in relation to plant yield and nutrient uptake responses. Field experiments involving wheat (Triticum aestivum; 'Katepwa') and peas (Pisum sativum; 'Titan') showed no yield or P uptake as a result of PB-50 seed inoculation or P2O5 fertilization for three locations. Fertilization of wheat with CuSO4 and peas with ZnSO4 produced increases in seed and total plant uptake of Cu and Zn. A yield increase from 2722 kg/ha to 3682 kg/ha (40 to 54 bu/ac) as a result of Cu fertilization was observed for Katepwa wheat on Nipawin Soil (DTPA Cu = 0.1 ug/g). No other yield increases were observed for Cu or Zn fertilization on the other soils. Growth chamber experiments involving wheat (Triticum aestivum; 'Park') and navy beans (Phaselous vulgaris L.) produced results similar to field experimentation. Increased Cu uptake in wheat for CuSO4 fertilized treatments was observed for all three soils. Copper fertilization in the Nipawin soil showed a yield increase in wheat relative to control. Wheat seed inoculation with PB-50 produced no yield increases and minor nutrient uptake differences. Increased yields and Zn uptake in beans for ZnSO4 fertilized treatments was observed in all three soils. Seed inoculation of navy bean with PB-50 produced variable yield increases and nutrient uptake differences in two of three soils

Multimode solutions of first-order elliptic quasilinear systems obtained from Riemann invariants

Two new approaches to solving first-order quasilinear elliptic systems of PDEs in many dimensions are proposed. The first method is based on an analysis of multimode solutions expressible in terms of Riemann invariants, based on links between two techniques, that of the symmetry reduction method and of the generalized method of characteristics. A variant of the conditional symmetry method for constructing this type of solution is proposed. A specific feature of that approach is an algebraic-geometric point of view, which allows the introduction of specific first-order side conditions consistent with the original system of PDEs, leading to a generalization of the Riemann invariant method for solving elliptic homogeneous systems of PDEs. A further generalization of the Riemann invariants method to the case of inhomogeneous systems, based on the introduction of specific rotation matrices, enables us to weaken the integrability condition. It allows us to establish a connection between the structure of the set of integral elements and the possibility of constructing specific classes of simple mode solutions. These theoretical considerations are illustrated by the examples of an ideal plastic flow in its elliptic region and a system describing a nonlinear interaction of waves and particles. Several new classes of solutions are obtained in explicit form, including the general integral for the latter system of equations

A Novel Quantitative Simple Brain Metric Using MR Imaging for Preterm Infants

BACKGROUND AND PURPOSE: The application of volumetric techniques to preterm infants has revealed brain volume reductions. Such quantitative data are not available in routine neonatal radiologic care. The objective of this study was to develop simple brain metrics to compare brain size in preterm and term infants and to correlate these metrics with brain volumes from volumetric MR imaging techniques.MATERIALS AND METHODS: MR images from 189 preterm infants &lt;30 weeks’ gestational age or &lt;1250 g birthweight scanned at term-equivalent age and 36 term infants were studied. Fifteen tissue and fluid measures were systematically evaluated on 4 selected sections. The results were correlated with total brain, gray matter, white matter, and CSF volumes. RESULTS: The mean bifrontal, biparietal, and transverse cerebellar diameters were reduced (−11.6%, 95% confidence interval [CI], −13.8% to −9.3%; −12%, 95% CI, −14% to −9.8%; and −8.7%, 95% CI, −10.5% to −7% respectively) and the mean left ventricle diameter was increased (+22.3%, 95% CI, 2.9%–41.6%) in preterm infants (P &lt; .01). Strong correlations were found between the bifrontal and biparietal measures with total brain tissue volume, whereas the size of the ventricles and the interhemispheric measure correlated with CSF volume. Intraobserver reliability was high (intraclass correlation coefficients [ICC], &gt;0.7), where interobserver agreement was acceptable for tissue measures (ICC, &gt;0.6) but lower for fluid measures (ICC, &lt;0.4) CONCLUSIONS: Simple brain metrics at term-equivalent age showed smaller brain diameters and increased ventricle size in preterm infants compared with full-term infants. These measures represent a reliable and easily applicable method to quantify brain growth and assess brain atrophy in this at-risk population

Neurodevelopmental and Perinatal Correlates of Simple Brain Metrics in Very Preterm Infants

OBJECTIVE: To explore perinatal correlates of 3 simple measures of brain size, known as metrics, in very preterm infants at term-equivalent age and their relationship to 2-year neurodevelopmental outcomes.DESIGN: Prospective cohort study of preterm infants born at a gestational age of less than 30 weeks or a weight of less than 1250 g between April 1, 2001, and December 31, 2003, and followed up at 2 years of corrected age. SETTING: The Royal Women\u27s Hospital and the magnetic resonance imaging unit at the Royal Children\u27s Hospital. PATIENTS: Two hundred thirty-six preterm infants. INTERVENTIONS: Brain metrics--biparietal, bifrontal, and transverse cerebellar diameters--on magnetic resonance imaging for preterm infants at term-equivalent age and neurodevelopmental assessments at 2 years of corrected age. MAIN OUTCOME MEASURES: Mental Development Index and the Psychomotor Development Index of the Bayley Scales of Infant Development-Revised. RESULTS: Higher birth weight z score, shorter duration of assisted ventilation, and postmenstrual age at magnetic resonance imaging were independently associated with increases in the 3 brain metrics, and male sex was associated with larger bifrontal and biparietal diameters. Only the biparietal diameter was predictive of cognitive and motor indices after adjustment for perinatal variables and social risk. CONCLUSION: This study provides further evidence of altered brain growth in preterm infants, relating to growth restriction and severity of illness, that in turn relate to neurodevelopmental outcome