PAR Reduction Research Articles

Deployment of IoT-Based Smart Demand-Side Management System with an Enhanced Degree of User Comfort at an Educational Institution

Nowadays, the Internet of Things (IoT) has a wide impact on many potential applications. The impact of IoT on performing demand-side management (DSM) in an Indian educational institution has not been researched in depth before. In this research work, an IoT-enabled SDSMS (Smart DSM System) has been deployed with the main objective of minimizing electricity tariff and also to tweak the quality of user comfort. It can be feasible by prioritizing available renewable PV solar energy during peak hours in an Indian educational institution. DSM has been performed using day-ahead load shifting and rescheduling the different classes of institutional loads by applying hybrid BPSOGSA (Binary Particle Swarm Optimization and Gravitational Search Algorithm). The BPSOGSA performance on DSM has been evaluated based on electricity tariff, peak demand range, and PAR and compared with the outcomes of both binary conventional algorithms BPSO and BGSA, respectively. The proposed method enhances the degree of user comfort (DUC) by tripping the operation of non-critical institutional loads. Simulation results obtained using MATLAB corroborate that BPSOGSA outperforms both BPSO and BGSA under both DSM scenarios. Before DSM, Peak demand, PAR, and Electricity tariffs were found to be 1855.47 kW, 4.1286, and $2030.67 while after DSM, they reduced to 1502.24 kW, 3.263, and $1314.40 respectively. This indicates a 35.273% reduction in electricity tariff, a 19.037% scale down in peak demand, and a 20.97% reduction in PAR. Finally, the real-time IoT-based SDSMS hardware is implemented at the Renewable energy laboratory for real monitoring of energy consumption via the Blynk application.

Power Scheduling with Max User Comfort in Smart Home: Performance Analysis and Tradeoffs

The smart grid has enabled users to control their home energy more effectively and efficiently. A home energy management system (HEM) is a challenging task because this requires the most effective scheduling of intelligent home appliances to save energy. Here, we presented a meta-heuristic-based HEM system that integrates the Greywolf Algorithm (GWA) and Harmony Search Algorithms (HSA). Moreover, a fusion initiated on HSA and GWA operators is used to optimize energy intake. Furthermore, many knapsacks are being utilized to ensure that peak-hour load usage for electricity customers does not surpass a certain edge. Hybridization has proven beneficial in achieving numerous objectives simultaneously, decreasing the peak-to-average ratio and power prices. Widespread MATLAB simulations are cast-off to evaluate the routine of the anticipated method, Harmony GWA (HGWA). The simulations are for a multi-family housing complex outfitted with various cool gadgets. The simulation results indicate that GWA functions better regarding cost savings than HSA. In reputes of PAR, HSA is significantly more effective than GWA. The suggested method reduces costs for single and ten-house construction by up to 2200.3 PKR, as opposed to 503.4 in GWA, 398.10 in HSA and 640.3 in HGWA. The suggested approach performed better than HSA and GWA in PAR reduction. For single-family homes in HGWA, GWA and HSA, the reduction in PAR is 45.79%, 21.92% and 20.54%, respectively. The hybrid approach, however, performs better than the currently used nature-inspired techniques in terms of Cost and PAR.

Comparing Points in Target Range Assessed by Blood Glucose Monitoring Using a Vacuum-based Lancing Device and Conventional Lancing Devices

Background: Time-in-range, the recently introduced metric is effective with CGM devices. Several reasons such as inaccessibility, out-of-pocket expense etc. challenge the wider acceptance of CGM devices globally. In this scenario a similar metric termed point-in-range (PIR) was introduced which can be calculated based on the frequent readings from blood glucose meters. Aim: The current study aims to compare the points in range in people with type 1 diabetes and type 2 diabetes using Genteel, a commercially available lancer that applies vacuum after lancing and a non-vacuum conventional lancing device. Methods: Data for the study was retrieved from an open-label, 24-week cross-over trial and analyzed retrospectively. The cohort included both patients with type 1 diabetes (n=58; age= 17.70 ± 10.18) and type 2 diabetes. The participants used Genteel for 12 weeks and then switched to a conventional lancing device for additional 12 weeks or vice versa. PIR was calculated and compared when using a Genteel and using a conventional lancer. Statistical analysis was carried out using SPSS software, version 16, and a significance threshold of P<0.05 was used. Results: Selected individuals with T1D, showed significantly higher frequency of blood glucose level falling within the range and significantly lower frequency of blood glucose level falling above range (PAR) while using Genteel in comparison to the conventional lancing devices. In addition, a significant reduction in HbA1c levels (from 8.94 ± 1.77% to 8.25 ± 1.67%) was observed among the subjects with T1D who used the Genteel device. No change in the frequency of blood glucose level falling within the range was observed in patients with type 2 diabetes. Conclusion: Painless glucose monitoring facilitated by Genteel may have contributed to the increased monitoring frequency which in turn contributed to higher PIR, lower PAR and significant reduction in the HbA1c.

The impact of obesity on orthodontic treatment outcome in adolescents: a prospective clinical cohort study.

This prospective clinical cohort study investigated the potential influence of obesity on orthodontic treatment outcome. A prospective cohort of adolescent patients undergoing routine fixed appliance treatment were recruited into normal-weight or obese groups based upon body mass index (BMI) centile and followed up until the completion of treatment. Primary outcome was treatment duration, and secondary outcomes included treatment outcome (occlusal change measured using peer assessment rating [PAR]), appointment characteristics, and compliance measures. A total of 45 patients mean age 14.8 (1.6) years were included in the final analysis. The normal-weight group included 23 patients with mean BMI 19.4 (2.4) kg/m2 and the obese group 22 patients with mean BMI 30.5 (3.8) kg/m2. There were no significant differences in baseline demographics between groups, except for BMI and pre-treatment PAR. The normal-weight group had a mean pre-treatment PAR of 25.6 (8.3) and the obese 33.3 (11.8) giving the obese group a more severe pre-treatment malocclusion (P = 0.02). There were no significant differences in treatment duration between groups (P = 0.36), but obese patients needed less time per each additional baseline PAR point compared to normal weight (P = 0.02). Obese patients also needed less appointments compared to normal-weight patients (P = 0.02). There were no significant differences between groups for appointment characteristics or compliance. Finally, obese patients were more likely to experience a great PAR reduction than normal-weight patients (relative risk = 2.6; 95% confidence interval = 1.2-4.2; P = 0.02). There were no significant differences in treatment duration between obese and normal-weight patients. Obesity does not appear to be a risk factor for negative orthodontic treatment outcome with fixed appliances.

Halophila stipulacea descriptors in the native area (Red Sea): A baseline for future comparisons with native and non-native populations

Halophila stipulacea is a small tropical seagrass species native to the Red Sea. Due to its invasive character, there is growing interest in understanding its ability to thrive in a broad range of ecological niches. We studied temporal (February 2014 and July 2014), depth (5, 9, 18 m) and spatial (NB and SB) related dynamics of H. stipulacea meadows in the northern Gulf of Aqaba. We evaluated changes in density, morphometry, biomass, and biochemical parameters alongside the reproductive effort. In both sites, maximal growth and vegetative performance occurred in the summer with a marked increase of 35% in shoot density and 18% in biomass; PAR reduction with season and depth induced a significant increase of 28% in leaf area. Sexual reproduction efforts were only observed in July, and the density of plants carrying male or female flowers decreased significantly with depth. The favorable growth responses of H. stipulacea plants observed in the N-enriched NB site suggests their capacity to acclimate to human-disturbed nearshore environments.

Morphology, yield and quality of greenhouse tomato cultivation with flexible photovoltaic rooftop panels (Almería-Spain)

Flexible photovoltaic panels are an option to generate renewable energy that could be compatible with the production of greenhouse crops, especially in warm sunny countries. The aim of this study was to evaluate, during two growing seasons, the effect of shading caused by flexible photovoltaic panels mounted on the greenhouse roof on tomato plant morphology and fruit yield and quality. This study was conducted during two growing seasons in a commercial greenhouse for tomato production. Two photovoltaic panel arrays placed on the greenhouse roof were analysed. Both occupied 9.8% of the cover. The parameters studied were PAR, plant morphology, crop yield and fruit quality. The results show that the small reduction in PAR caused by flexible photovoltaic panels on the roof did not affect the total and marketable yield; plant morphology; number of flowers per branch; and fruit colour, firmness and pH. However, the fruit diameter decreased, without affecting the yield (kg·m−2). Both flexible photovoltaic panel arrays on the greenhouse roof produced a similar effect on plant morphology, crop yield and fruit quality.

392P - Generation of a novel preclinical PK/PD model provides insights into PARP inhibitor clinical monotherapy activity

Background: In Phase II trials, an olaparib capsule dose that inhibits PARP (100 mg bd) was clinically inferior to the MTD (400 mg bd). Using an in vivo model, we investigated this discrepancy and the effect of dose and schedule on tumour progression. Methods: PK, PD and antitumour activity were assessed using olaparib (100, 50, 25, 10, 2.5 mg/kg qd) in a breast cancer patient-derived xenograft (PDX) with mutated BRCA2 and TP53. We studied the relationship between PARP1 inhibition and DNA single-strand breaks (SSBs) by creating a mathematical model. We also compared PK/PD model parameters with free minimum olaparib steady-state plasma concentration (Cmin,ss) in seven Phase I–III clinical studies. Results: Only 100 and 50 mg/kg olaparib doses caused tumour regression, yet all but the lowest led to acute PAR inhibition. The differentiating factor was time over PAR IC95; simulations using the mathematical model at steady state predicted a threshold where >95% reduction in PAR caused >20-fold increase in DNA SSBs. Overlaying clinical data, we saw that 400 mg bd capsule and 300 mg bd tablet doses provide continuous PAR inhibition (Cmin,ss>IC95 upper confidence level); 100 mg bd capsule does not. Dosing schedule assessment showed PDX regression with continuous 100 mg/kg olaparib (0/10 tumours progressed by day 100). By contrast, continuous dosing at 50 mg/kg or intermittent dosing (1 wk on/1 wk off) at 100 mg/kg resulted in 2/10 and 10/10 progressions, respectively. Treatment withdrawal upon regression led to regrowth in all cases; re-challenge at continuous 100 mg/kg was effective (9/10 regressions), 50 mg/kg was not (0/10). In a maintenance setting, switching to lower or intermittent dosing resulted in tumour response more similar to that of continuous 100 mg/kg (1/10, 2/10 and 0/10 progressions, respectively). Conclusions: Discrepancy between biologically and clinically effective olaparib doses is explained by a need for continuous >95% PAR inhibition. Both the 400 mg bd capsule and 300 mg bd tablet dose, used in the ongoing clinical programme, provide this. Dosing schedule data suggest continuous PAR inhibition is also needed for long-term responses. These data highlight important principles for treatment of patients with PARP inhibitor monotherapy. Legal entity responsible for the study: AstraZeneca Funding: AstraZeneca Disclosure: M. O'Connor, E. Cadogan, A. Hughes, M. Learoyd, H. Xu, J. Li, J. Yates: Employee of AstraZeneca and owns stock with AstraZeneca. E. Leo: Employee of AstraZeneca.

Growth, productivity and quality of Megathyrsus maximus under cover from Gliricidia sepium

The effect of tree canopy on the growth, productivity and forage quality of Megathyrsus maximus and changes in soil properties were evaluated over three seasonal periods. Four adjacent plots (15 m × 17 m each) in a tropical secondary deciduous forest having 12 years of growth and dominated by Gliricidia sepium were randomly assigned to two treatments: removal of trees (SCA) in two of the plots and leaving trees intact (COA) in the other two. In all plots, M. maximus was planted with 50 cm spacing among plants. Tree removal significantly increased the incident photosynthetically active radiation (PAR, P < 0.001) and grass size (12.5 % in height, P < 0.01, and 16.5 % in clump diameter, P < 0.05), but did not significantly affect any other variable. Season significantly affected grass height (P < 0.003), tiller number (P < 0.001), clump diameter (P < 0.001), net CO2 assimilation rate (P < 0.001), forage biomass production (P < 0.003), and acid detergent fiber content (P = 0.033). Primary soil changes after 1 year of establishment of the grass were the decline by 3 % in organic carbon (P = 0.03), and qualitative changes in soil structure, regardless of tree presence. Results are consistent with the ability of M. maximus to tolerate shade. We conclude that under the conditions of the study there was no evidence for a negative effect of tree canopy on M. maximus mediated by a reduction in PAR.

Androgen receptor phosphorylation at serine 515 by Cdk1 predicts biochemical relapse in prostate cancer patients

Background:Prostate cancer cell growth is dependent upon androgen receptor (AR) activation, which is regulated by specific kinases. The aim of the current study is to establish if AR phosphorylation by Cdk1 or ERK1/2 is of prognostic significance.Methods:Scansite 2.0 was utilised to predict which AR sites are phosphorylated by Cdk1 and ERK1/2. Immunohistochemistry for these sites was then performed on 90 hormone-naive prostate cancer specimens. The interaction between Cdk1/ERK1/2 and AR phosphorylation was investigated in vitro using LNCaP cells.Results:Phosphorylation of AR at serine 515 (pARS515) and PSA at diagnosis were independently associated with decreased time to biochemical relapse. Cdk1 and pCdk1161, but not ERK1/2, correlated with pARS515. High expression of pARS515 in patients with a PSA at diagnosis of ⩽20 ng ml−1 was associated with shorter time to biochemical relapse (P=0.019). This translated into a reduction in disease-specific survival (10-year survival, 38.1% vs 100%, P<0.001). In vitro studies demonstrated that treatment with Roscovitine (a Cdk inhibitor) caused a reduction in pCdk1161 expression, pARS515expression and cellular proliferation.Conclusion:In prostate cancer patients with PSA at diagnosis of ⩽20 ng ml−1, phosphorylation of AR at serine 515 by Cdk1 may be an independent prognostic marker.

Modeling pharmacodynamic response to the poly(ADP-Ribose) polymerase inhibitor ABT-888 in human peripheral blood mononuclear cells.

BackgroundPoly(ADP-ribose) polymerase (PARP)facilitates DNA repair and PARP inhibitors may potentiate the effect of DNA-damaging chemotherapeutic agents in patients with cancer. Collection of peripheral blood mononuclear cells (PBMCs)as a surrogate tissue to monitor PARP inhibitor pharmacodynamic effects has several advantages over tumor biopsy collection, including minimally invasive sample collection and the ability to collect multiple samples for longitudinal assessment of drug effect.Methodology/Principal FindingsUsing our previously validated immunoassay for measuring poly(ADP-ribose) (PAR), a product of PARP, in tumor biopsies, we validated a method to quantify PAR levels in PBMCs to monitor the pharmacodynamic effects of the PARP inhibitor ABT-888 in clinical trials. The inter-individual variation in PAR levels was large. No significant difference (P = 0.67) was measured between median baseline PAR levels in 144 healthy volunteers (131.7 pg/1×107 PBMCs [interquartile range, 79.5–241.6]) and 49 patients with cancer (149.2 pg/1×107 PBMCs [interquartile range, 83.2–249.3]). In addition, PAR levels monitored in healthy volunteers over 3 weeks had considerable intra- and inter-individual variation (range, 44–1073 pg PAR/1×107 PBMCs). As a pharmacodynamic model, we quantified changes in PAR levels in human PBMCs treated ex vivo with clinically relevant concentrations of ABT-888. Of 40 healthy volunteer PBMC samples treated with ABT-888, 47.5% had greater than 50% PAR reduction compared to vehicle-treated controls. Considerable inter-sample heterogeneity in PAR levels was measured, and several ABT-888–insensitive samples were identified.Conclusions/SignificanceOur results emphasize the importance of using a validated method to measure PAR levels, and support further investigation into the role of PARP in PBMCs. To this end, the PAR immunoassay has been validated for use with PBMCs and incorporated into clinical trials to assess PBMCs as a potential pharmacodynamic surrogate for tumor biopsies in clinical trials of PARP inhibitors.

Differences in morphology, gas exchange and root hydraulic conductance before planting in Pinus canariensis seedlings growing under different fertilization and light regimes

As the main forestry species in the Canary Islands (Spain), Pinus canariensis is frequently used in afforestation programs. Several nursery techniques are commonly employed to modify its morphology and physiology with the aim of improving post-planting survival and growth. In this work, we studied how fertilization and light regime treatments applied during the nursery period modify biomass allocation patterns and produce effects in gas exchange and root hydraulic conductance. Seedlings were grown for a 6-month period in the nursery under two light regimes (full sunlight and 40% PAR reduction), and three fertilization levels were applied in each light regime. Morphology, biomass allocation patterns, leaf gas exchange and hydraulic conductance of the whole root system were evaluated. Fertilization treatments produced significant changes in biomass allocation, gas exchange and root hydraulic conductance under both light regimes. In contrast, no differences were found between full sunlight and shade, except for a slight variation in the root:shoot ratio. Photosynthesis rate and WUE increased with fertilization in both light regimes, while E and gs maintained the same values. An opposite trend was observed for root hydraulic conductance, which showed lower values with high fertilization regimes. The results obtained indicate that fertilization is more important, determining high photosynthetic capacity than high hydraulic conductance rates before planting in Pinus canariensis containerized seedlings.

Pharmacodynamic response in phase I combination study of ABT-888 and topotecan in adults with refractory solid tumors and lymphomas.

2514 Background: Poly(ADP-ribose) (PAR) polymerase (PARP) inhibitors such as ABT-888 may prevent efficient repair of DNA damage induced by topoisomerase 1 inhibitors and lead to double-strand breaks, which activate DNA-damage signaling pathways through phosphorylation of histone H2AX (γH2AX). We evaluated the pharmacodynamics (PD) of ABT-888 and topotecan alone and in combination through quantitative detection of PARP activity and γH2AX foci in peripheral blood mononuclear cells (PBMCs) and tumor samples. Methods: PBMCs and tumor biopsies (optional) were collected, and validated assays were used to compare pre- and post-treatment levels of γH2AX and PAR, a product of PARP. PAR was measured by ELISA and γH2AX by immunofluorescence assay. Results: We enrolled 24 patients (pts) with refractory solid tumors and lymphomas. The dose of topotecan was reduced and administration schedule changed due to myelosuppression (Table). PARP was modulated by the various administration schedules. In PBMCs, >50% reduction in PAR was observed in 13 of 18 pts. When ABT-888 was given on D1 only, PAR levels in PBMCs returned to baseline levels by D2 in 3 of 5 pts. In the 3 pts for whom paired tumor biopsies were available, PAR reduction was 89.3% (pt on dose level [DL] 1), 98.7% (pt on DL-2), and 75.5% (pt on DL-3). Topotecan did not appear to alter the ability of ABT-888 to inhibit PARP. Elevated levels of γH2AX were detected in PBMCs after doses of 0.9 and 1.2 mg/m2/day topotecan alone but not lower doses. However, when given with ABT-888, 3 of 7 pts on DL-3 and all 3 pts on DL-2 had significant increases in γH2AX. γH2AX upregulation was associated with PARP inhibition; mean PAR reduction ± SD in PBMCs 2 h post-dose in pts on DL −3 was 97.8% ± 5.5% for γH2AX responders vs. 52.3% ± 28.1% for nonresponders. Conclusions: The PARP inhibitor ABT-888 potentiated DNA damage caused by topotecan as indicated by the increase in γH2AX foci. Funded by NCI Contract HHSN261200800001E. Dose and days (D) of administration Dose level Topotecan IV (mg/m2/day) ABT-888 (10 mg q12h PO) No. of patients 1 1.2 (D-8, 2-5) D1-7 6 −1 0.9 (D-8, 2-5) D1-7 3 −2 0.75 (D1-5) D2-5 3 −3 0.6 (D1-5) D2-5 7 1A 0.75 (D1-5) D1 only 5 No significant financial relationships to disclose.

Adaptive active constellation extension algorithm for peak-to-average ratio reduction in OFDM

For PAR reduction in OFDM systems, the clipping-based Active Constellation Extension (ACE) technique is simple and attractive for practical implementation. However, we observe it cannot achieve the minimum PAR when the target clipping level is set below an initially unknown optimum value. To overcome this low clipping ratio problem, we propose a novel ACE algorithm with adaptive clipping control. Simulation results demonstrate that our proposed algorithm can reach the minimum PAR for severely low clipping ratios. In addition, we present the tradeoff between PAR and the loss in E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">b</sub> /N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sub> over an AWGN channel in terms of the clipping ratio.

An enzyme-linked immunosorbent poly(ADP-ribose) polymerase biomarker assay for clinical trials of PARP inhibitors

Many established cancer therapies involve DNA-damaging chemotherapy or radiotherapy. The DNA repair capacity of the tumor represents a common mechanism used by cancer cells to survive DNA-damaging therapy. Poly(ADP-ribose) polymerase (PARP) is a nuclear enzyme that is activated by DNA damage and has critical roles in DNA repair. Inhibition of PARP potentiates the activity of DNA-damaging agents such as temozolomide, topoisomerase inhibitors and radiation in both in vitro and in vivo preclinical models. Recently, several PARP inhibitors have entered clinical trials either as single agents or in combination with DNA-damaging chemotherapy. Because PARP inhibitors are not cytotoxic, a biomarker assay is useful to guide the selection of an optimal biological dose. We set out to develop an assay that enables us to detect 50% PAR reduction in human tumors with 80% power in a single-plate assay while assuring no more than a 10% false-positive rate. We have developed and optimized an enzyme-linked immunosorbent assay (ELISA) to measure PARP activity that meets the above-mentioned criterion. This robust assay is able to detect PAR levels of 30–2000 pg/ml in both tumor and peripheral blood monocyte samples. In a B16F10 mouse syngeneic tumor model, PARP inhibitor ABT-888 potentiates the effect of temozolomide in suppressing tumor growth, and PARP activity is greatly reduced by ABT-888 at efficacious doses. In summary, the ELISA assay described here is suitable for biomarker studies in clinical trials of PARP inhibitors.

Tratamento da má oclusão de Classe II de Angle em duas fases: avaliação da efetividade e eficácia por meio do índice PAR

OBJETIVO: Do presente estudo foi comparar o resultado do tratamento ortodôntico de pacientes portadores de má oclusão classe II, divisão 1 tratados em uma e em duas fases (tratamento precoce). METODOLOGIA: A amostra final foi constituída de forma aleatória por 72 pacientes portadores de Classe II (31 do gênero masculino e 41 do gênero feminino), tratados por seis ortodontistas da rede privada. A idade média observada foi de 11,8 (dp=2,5) e 9,58 (dp=1,6) anos para os grupos de uma (n=36) e duas fases (n=36), respectivamente. RESULTADOS: As médias dos valores cefalométricos iniciais e do valor inicial do Índice de Avaliação entre Pares ou Peer Assessment Rating (PAR) nos dois grupos foram comparados pelo teste t-Student, não havendo diferença significativa entre eles, comprovando-se sua equivalência inicial com relação à gravidade dos casos. O resultado do tratamento foi avaliado aplicando-se o PAR aos modelos de estudo iniciais e finais dos pacientes entre os grupos (p=0,647), sendo encontrada uma redução média do índice de 83% e 85% para o grupo de uma e duas fases, respectivamente. A média de duração de tratamento total foi de 43,1 meses para o grupo de duas fases e de 35 meses para o grupo de uma fase, sendo a diferença entre eles significativa (p=0,0158). CONCLUSÕES: A correlação entre o tempo de tratamento e a gravidade inicial do caso foi baixa, porém positiva, contudo, não foi encontrada relação entre o gênero do paciente e a duração da intervenção, com a qualidade final da mesma. Apesar do presente estudo não ter identificado diferenças significativas entre resultados médios, futuros trabalhos deveriam ter como objetivo identificar, com mais exatidão, quais os tipos de pacientes a serem de fato beneficiados por um tratamento precoce.

Effects of Kaolin Application on Light Absorption and Distribution, Radiation Use Efficiency and Photosynthesis of Almond and Walnut Canopies

Kaolin applied as a suspension to plant canopies forms a film on leaves that increases reflection and reduces absorption of light. Photosynthesis of individual leaves is decreased while the photosynthesis of the whole canopy remains unaffected or even increases. This may result from a better distribution of light within the canopy following kaolin application, but this explanation has not been tested. The objective of this work was to study the effects of kaolin application on light distribution and absorption within tree canopies and, ultimately, on canopy photosynthesis and radiation use efficiency. Photosynthetically active radiation (PAR) incident on individual leaves within the canopy of almond (Prunus dulcis) and walnut (Juglans regia) trees was measured before and after kaolin application in order to study PAR distribution within the canopy. The PAR incident on, and reflected and transmitted by, the canopy was measured on the same day for kaolin-sprayed and control trees in order to calculate canopy PAR absorption. These data were then used to model canopy photosynthesis and radiation use efficiency by a simple method proposed in previous work, based on the photosynthetic response to incident PAR of a top-canopy leaf. Kaolin increased incident PAR on surfaces of inner-canopy leaves, although there was an estimated 20 % loss in PAR reaching the photosynthetic apparatus, due to increased reflection. Assuming a 20 % loss of PAR, modelled photosynthesis and photosynthetic radiation use efficiency (PRUE) of kaolin-coated leaves decreased by only 6.3 %. This was due to (1) more beneficial PAR distribution within the kaolin-sprayed canopy, and (2) with decreasing PAR, leaf photosynthesis decreases less than proportionally, due to the curvature of the photosynthesis response-curve to PAR. The relatively small loss in canopy PRUE (per unit of incident PAR), coupled with the increased incident PAR on the leaf surface on inner-canopy leaves, resulted in an estimated increase in modelled photosynthesis of the canopy (+9 % in both walnut and almond). The small loss in PRUE (per unit of incident PAR) resulted in an increase in radiation use efficiency per unit of absorbed PAR, which more than compensated for the minor (7 %) reduction in canopy PAR absorption. The results explain the apparently contradictory findings in the literature of positive or no effects of kaolin applications on canopy photosynthesis and yield, despite the decrease in photosynthesis by individual leaves when measured at the same PAR.

Retrospective analysis of orthodontic treatment outcomes and its relation to postretention stability.

Objective:The present study was designed to retrospectively evaluate Class I malocclusion cases treated with extraction of the four first premolars, aiming to establish the relationship between the quality of orthodontic treatment outcomes and the long-term occlusal stability.Material and methods:The sample comprised 94 patients of both genders, presenting Class I malocclusion, treated with extractions of the four first premolars and Edgewise mechanics. All the patients selected were whites, being 50 males and 44 females. The mean pretreatment age was 13.46 years (s.d. 1.8). The mean treatment time was 2.09 years (s.d. 0.58), the mean retention time was 1.63 years (s.d. 0.73) and the mean time of postretention evaluation was 5.31 years (s.d. 1.61). The dental casts were measured at pretreatment (T1), posttreatment (T2) and postretention (T3), by the PAR index and by the Little irregularity index, and the correction due to treatment (T1-2) and the change at the postretention period (T3-2) were calculated. The descriptive statistics was performed and the Pearson correlation coefficient was applied for the PAR and the Little indices in the total sample, among the times evaluated.Results:The mean PAR reduction due to treatment was 78.54%, and 66.6%, at the postretention stage related to pretreatment stage. Significant correlations were found for the PAR index at the times evaluated, except between T1 and T2 and between T1-2 and T3. In other words, the higher the treatment correction (T1-2), the lower the posttreatment PAR index (PAR T2) will be, and the higher will be the PAR change at the postretention period (PAR T3-2). Also, the higher the posttreatment PAR score (PAR T2), the higher will be the postretention PAR score (PAR T3).Conclusion:It was concluded that the quality of orthodontic treatment outcomes is not related to the long-term occlusal stability.

Comparison of Class I and Class II Treatment Duration Among Three Different Orthodontic Practices

The purpose of this investigation was to assess the relative treatment time difference (months/appointments) between Class II Division 1 patients and Class I patients from 3 different orthodontic offices. In addition, we also compared the estimated treatment length with the actual treatment length to determine how accurate the orthodontists were in predicting treatment duration. A total sample of 237 patients representing 3 observational groups (Angle Class I nonextraction, and Class II Division I extraction and nonextraction) were selected from the active retention files of each office. Pretreatment ANB angle, pretreatment overjet, and the pre- and posttreatment PAR scores (weighted) were measured. The results of this investigation indicated that among the 3 orthodontic offices, Class II Division 1 cases took an average of 5 more months than Class I cases. There was no significant treatment time difference (months) between the Class II extraction and nonextraction groups. Class II treatments including Herbst therapy were significantly longer (around 8 months) than treatments including headgears. The treatment length in 4 of the 9 observational groups was significantly underestimated and our data demonstrated no association of pretreatment PAR scores and percentage PAR reduction with treatment duration.

An audit of ‘early debond’ cases in the national outcomes audit of patients treated with upper and lower fixed appliances by Consultant Orthodontists in the UK

To audit the outcomes of the 'early debond' cohort of the national outcomes audit carried out by the Consultant Orthodontic Group of the British Orthodontic Society. Multi-centre, retrospective national audit. Seventy-five per cent of cases should exhibit a reduction in PAR greater than 70% with 3% or less with a PAR score reduction of less than 30% (i.e. worse/no different). Analysis of consecutively completed cases treated by upper and lower fixed appliances that were noted by the operator as having discontinued treatment early. Incidence of early debond, PAR outcome. The 'early debond' cohort constituted 11% of the total 823 patients and fell below previously published standards for orthodontic treatment outcomes. They were less likely to be in the 'greatly improved' category, more likely to be in the 'improved' category and only slightly more likely to be in the 'worse/no different' category. There was a 67% reduction in PAR and 50% exhibited a reduction in PAR greater than 70%, with 6.5% having a reduction in PAR score lower than 30%. Discontinuation of orthodontic treatment is associated with a reduced level of treatment outcome.

A simplified clipping and filtering technique for PAR reduction in OFDM systems

The existing iterative clipping and filtering techniques require several iterations to mitigate the peak regrowth. In this letter, we analyze the conventional clipping and filtering using a parabolic approximation of the clipping pulse. We show that the clipping noise obtained after several clipping and filtering iterations is approximately proportional to that generated in the first iteration. Therefore, we scale the clipping noise generated in the first iteration to get a new clipping and filtering technique that, with three fast Fourier transform/inverse fast Fourier transform (FFT/IFFT) operations, obtains the same PAR reduction as that of the existing iterative techniques with 2K+1 FFT/IFFT operations, where K represents the number of iterations.