Rate Schedule Research Articles

Water savings, nutrient leaching, and fruit yield in a young avocado orchard as affected by irrigation and nutrient management

This project was designed to determine the effect of fertilizer rate and irrigation scheduling on water use, nutrient leaching, and fruit yield of young avocado trees (Persea americana Mill. cv. Simmonds). Seven nutrient and irrigation management practices were evaluated: (1) irrigation based on crop evapotranspiration (ET) with 50% fertilizer at a standard rate (FSR); (2) ET irrigation with FSR (typical for avocado production in the area); (3) ET irrigation with 200% FSR; (4) irrigation based on exceedance of 15-kPa (SW) soil water suction with 50% FSR; (5) SW with FSR; (6) SW with 200% FSR; and (7) irrigation at a set schedule (based on timing and frequency typically used in local avocado production) with FSR. The SW with FSR treatment saved 87% of the water volume applied and reduced total phosphorus leached by 74% compared to the set schedule irrigation with FSR. The SW with FSR treatment had higher avocado fruit production, tree water-use efficiency, and fertilizer-use efficiency than the other six treatments. Thus, the use of soil water monitoring for irrigation management can substantially increase sustainability of young avocado orchards in southern Florida.

Motivational control of impulsive behavior interacts with choice opportunities

Impulsive behavior has been investigated through choice between a smaller/immediate reinforcer and a larger/delayed reinforcer, or through performance on a differential reinforcement of low rate (DRL) schedule. In the present study, we investigated a methodological divergence between these two procedures: in the former procedure, delay is a consequence of the subject's own choice, whereas in the later procedure, subjects are explicitly reinforced for delaying a response. In Experiment 1, 7 rats maintained at 80% of their free-feeding weights showed poorer efficiency of lever-pressing responses on a DRL 30-s schedule than when they were maintained at 90% of free-feeding weight. In Experiment 2, 16 rats were subjected to a concurrent chain schedule: the initial link was concurrent fixed ratio 1 fixed ratio 1, and each of these alternatives was followed by a short-DRL requirement with a one pellet reinforcer or a long-DRL requirement with a three pellet reinforcer. In one block of trials, rats were not allowed to choose between the two terminal links (forced-choice), whereas in the other block of trials rats were allowed to choose freely between the two terminal links (free-choice). Compared with rats maintained at 95% of their free-feeding weights, rats maintained at 80% of their free-feeding weights showed poorer efficiency in the terminal links’ DRL schedule performance (just as in Experiment 1), but this difference was shown only in the forced-choice blocks. These results indicate that motivational control of DRL schedule performance interacts with type of choice-making opportunity and highlight the direct comparison of motivational control of impulsive choice and DRL schedule performance.

A comparison of adult and adolescent rat behavior in operant learning, extinction, and behavioral inhibition paradigms.

Poor self-control, lack of inhibition, and impulsivity contribute to the propensity of adolescents to engage in risky or dangerous behaviors. Brain regions (e.g., prefrontal cortex) involved in impulse-control, reward-processing, and decision-making continue to develop during adolescence, raising the possibility that an immature brain contributes to dangerous behavior during adolescence. However, very few validated animal behavioral models are available for behavioral neuroscientists to explore the relationship between brain development and behavior. To that end, a valid model must be conducted in the relatively brief window of adolescence and not use manipulations that potentially compromise development. The present experiments used three operant arrangements to assess whether adolescent rats differ from adults in measures of learning, behavioral inhibition, and impulsivity, within the aforementioned time frame without substantial food restriction. In Experiment 1, separate squads of rats were trained to lever-press and then transitioned to two types of extinction. Relative to their baselines, adolescent rats responded more during extinction than adults, suggesting that they were less sensitive to the abolishment of the reinforcement contingency. Experiment 2 demonstrated similar age-related differences during exposure to a differential reinforcement of low rates schedule, a test of behavioral inhibition. Lastly, in Experiment 3, adolescent's responding decreased more slowly than adults during exposure to a resetting delay of reinforcement schedule, suggesting impaired self-control. Results from these experiments suggest that adolescents exhibit impaired learning, behavioral inhibition and self-control, and in concert with recent reports, provide researchers with three behavioral models to more fully explore neurobiology of risk-taking behavior in adolescence.

Hessian matrix distribution for Bayesian policy gradient reinforcement learning

Bayesian policy gradient algorithms have been recently proposed for modeling the policy gradient of the performance measure in reinforcement learning as a Gaussian process. These methods were known to reduce the variance and the number of samples needed to obtain accurate gradient estimates in comparison to the conventional Monte-Carlo policy gradient algorithms. In this paper, we propose an improvement over previous Bayesian frameworks for the policy gradient. We use the Hessian matrix distribution as a learning rate schedule to improve the performance of the Bayesian policy gradient algorithm in terms of the variance and the number of samples. As in computing the policy gradient distributions, the Bayesian quadrature method is used to estimate the Hessian matrix distributions. We prove that the posterior mean of the Hessian distribution estimate is symmetric, one of the important properties of the Hessian matrix. Moreover, we prove that with an appropriate choice of kernel, the computational complexity of Hessian distribution estimate is equal to that of the policy gradient distribution estimates. Using simulations, we show encouraging experimental results comparing the proposed algorithm to the Bayesian policy gradient and the Bayesian policy natural gradient algorithms described in Ghavamzadeh and Engel [10].

Rate Scaling Laws in Multicell Networks Under Distributed Power Control and User Scheduling

We analyze the sum rate performance in multicell single-hop networks where access points are allowed to cooperate in terms of a joint resource allocation. The resource allocation policies considered here combine power control and user scheduling. Although promising from a conceptual point of view, the optimization of the sum of per-link rates hinges on tough issues such as computational complexity and the requirement for heavy receiver-to-transmitter and cell-to-cell channel information feedback. In this paper, however, we show that simple distributed algorithms can scale optimally in terms of rates, when the number of users per cell U is allowed to grow large. We use extreme value theory to provide scaling laws for upper and lower bounds for the network sum-rate (sum of single user rates over all cells), corresponding to zero-interference and worst-case interference scenarios. We show that the scaling is either dominated by path loss statistics or by small-scale fading, depending on the regime and user location scenario. A surprising result is that the well known log log U rate behavior exhibited in i.i.d. fading channels with maximum rate schedulers is transformed into a log U behavior when path loss is accounted for. Additionally, by showing that upper and lower rate bounds behave in fact identically, asymptotically, our results suggest, remarkably, that the impact of multicell interference on the rate (in terms of scaling) actually vanishes asymptotically, when appropriate resource allocation policies are used.

‘Social dysmetria’ in first-episode psychosis patients

The 'embodied cognition' hypothesis suggests a close relationship between internal self-representations and the outward expression of social behaviours and emotions. Given self-awareness disturbances in patients with first-rank symptoms (FRS), we hypothesized that these patients would show abnormal social behaviours. In this study, we examined the social interactive skills of patients with first-episode psychosis during an interview, together with changes in performance over time. We analysed previously unreported data from 227 patients with first-episode psychosis (90 with, and 137 without, FRS) who took part in the WHO multicentre study on the Determinants of Outcome of Severe Mental Disorders. They were assessed on the Psychological Impairment Rating Schedule (PIRS) and examined again after 2 years. A principal component analysis on the Psychosocial Impairment Rating Schedule produced two factors (interactive skills; withdrawal from interactions). Patients with FRS showed greater impairments in the domain linked to 'interactive skills', which remained 2 years after the first experience of a psychotic illness. These findings were not explained by clinical characteristics, or presence of non-FRS delusions. Self-awareness deficits, as indexed by the FRS symptom cluster, are linked to deficits in social interactive behaviours. These abnormalities are indicative of 'social dysmetria' in this group, which involves difficulties conveying motor aspects of behaviours, volition and affect to facilitate mutual communication. These findings point to the utility of behavioural assessment scales in clinical and research settings.

Comparative Analysis of Impairment Evaluations by the 1996 Florida Uniform Permanent Impairment Rating Schedule (FUPIRS) and the AMA Guides™ Fourth, Fifth, and Sixth Editions

Abstract The Florida workers’ compensation system uses the 1996 Florida Uniform Permanent Impairment Rating Schedule (FUPIRS), that was based in part on the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Third Revised and Fourth Editions (the latter published in 1993). The authors ask if changes in the AMA Guides resulted in different impairment ratings and different awards. To these ends, the authors examined seventy-five cases that were randomly selected from a cohort of two hundred cases that was studied previously [see The Guides Newsletter, January/February 2010]. The average whole person impairment (WPI) per case was 5.3% WPI according to FUPIRS; 5.3% WPI according to the AMA Guides, Fourth Edition; 5.8% WPI according to the fifth edition; and 4.6% WPI according to the sixth edition. The difference between the WPIs was tested using a paired sample t test (alpha = .05), and results showed that the difference in WPI between FUPIRS and the sixth edition (0.7% WPI) was not statistically significant. The authors acknowledge that the limited range of impairment values in this study may have contributed to the lack of statistical significance when group means are compared because 84% of the cases were rated 10% WPI or less. The authors call for an expanded study to determine if meaningful differences exist between rating methodologies in a more diverse, less skewed sample.

When is a tempo effect a tempo distortion

Our aim is to clarify the fundamental conceptual difference between a tempo effect and a tempo distortion and to answer the question of which uses of quantum and tempo measures lead to distortions. We conclude that tempo effects are widespread in period measures, but that the need for adjustment depends on the purpose of the indicator. When the objective is to measure current conditions, as is usually the case, two approaches exist. In the classical approach, current age specific event rates are assumed to reflect fully current conditions. In contrast, we argue that current rates and the tempo effects in measures derived from them do not in general reflect current conditions. When changes in the timing of demographic events shift rates schedules to higher or lower ages, constant conditions may imply changing rates. In that case, tempo effects are distortions that need to be corrected in order to get an accurate measurement of current conditions. John BONGAARTS, Vice-President and Distinguished Scholar, Population Council, One Dag Hammarskjold Plaza, New York NY 10017, U.S.A. E-mail: jbongaarts@popcouncil.org . Griffith FEENEY, Scardale, New York, U.S.A., E-mail griffithfeeney@gmail.com . DOI: 10.4402/genus-188

Optimal Cogeneration Technology Selection for Residential and Commercial Buildings

The energy requirements for most residential and commercialbuildings show both annual or seasonal, and daily variations. In addi-tion, depending on the electrical rate schedule and location, there canbe time-of-use variation in the prices a customer pays for electricity.Such facts make it harder to select (a) the best-fit equipment for the hostbuilding and (b) the best operating strategy for the selected equipment.This article proposes a mixed integer programming (MILP) model tohelp decide the optimal make up of a prospect cogeneration system asapplied to a residential complex located in Zaragoza, Spain. The modelconsiders the possibility of whether to use or not a set of proposed al-ternative technologies within a previously defined superstructure. Suchsuperstructure is defined through binary variables and takes into ac-count the optimal operation of all feasible combinations of technologiesthroughout a typical meteorological year. The model’s objective functionis to minimize the total annual cost, which includes the cost of investedcapital, subject to technical, economic and legal constraints.

BWR in-core fuel management optimization using parallel simulated annealing in FORMOSA-B

The process of finding optimized fuel reload patterns for boiling water reactors is complicated by a number of factors including the large number of fuel assemblies involved, the three-dimensional neutronic and thermal-hydraulic variations, and the interplay of coolant flow rate with control rod programming. The FORMOSA-B code was developed to provide an automated method for finding fuel loading patterns, control rod programs and coolant flow rate schedules to minimize certain quantitative metrics of core performance while satisfying given operational constraints. One drawback of this code has been the long runtimes required for a complete cycle optimization on a desktop workstation (oftentimes several days or more). To address this shortcoming, a parallel simulated annealing algorithm has been added to the FORMOSA-B code, so that the runtimes may be greatly reduced by using a multiprocessor computer cluster. Tests of the algorithm on a sample problem indicate that it is capable of parallel efficiencies exceeding 80% when using four processors.

Tax–benefit revealed social preferences

This paper inverts the usual logic of applied optimal income taxation. It starts from the observed distribution of income before and after redistribution and corresponding marginal tax rates. Under a set of simplifying assumptions, it is then possible to recover the social welfare function that would make the observed marginal tax rate schedule optimal. In this framework, the issue of the optimality of an existing tax–benefit system is transformed into the issue of the shape of the social welfare function associated with that system and whether it satisfies elementary properties. This method is applied to the French redistribution system with the interesting implication that the French redistribution authority may appear, under some plausible scenario concerning the size of the labor supply behavioral reactions, non Paretian (e.g. giving negative marginal social weights to the richest class of tax payers).

Cross-Layer Joint Rate Control and Scheduling for OFDMA Wireless Mesh Networks

We consider the utility-maximization problem in the downlink of wireless mesh networks with orthogonal frequency-division multiple access (OFDMA). We formulate this problem as a cross-layer design of joint rate control and OFDMA scheduling to efficiently utilize the scarce radio resources. The problem is decoupled into a rate-control problem at the transport layer and a channel-aware and queue-aware scheduling problem at the Media Access Control/physical layer (MAC/PHY). The rate-control problem adjusts arrival rates to the base station (BS) queues, and the scheduling problem determines link rates, i.e., departure rates from the BS and other network nodes, through subcarrier and modulation rate assignment. Although the rate-control problem is locally solved at the BS, we propose a greedy algorithm that solves the scheduling problem in a distributed manner, at network nodes. Furthermore, we propose a heuristic algorithm for fast execution of the scheduling scheme at individual nodes. Numerical results show that the heuristic algorithm performs comparably with the greedy algorithm, whereas it has lower computational complexity. In addition, our proposed scheduling scheme, when it cooperates with the rate-control mechanism, improves the network performance in terms of end-to-end delay, aggregate utility, and fairness.

Early temporal short-term memory deficits in double transgenic APP/PS1 mice

We tested single APP (Tg2576) transgenic, PS1 (PS1dE9) transgenic, and double APP/PS1 transgenic mice at 3 and 6 months of age on the acquisition of a hippocampal-dependent operant "differential reinforcement of low rate schedule" (DRL) paradigm. In this task mice are required to wait for at least 10 seconds (DRL-10s) between 2 consecutive nose poke responses. Our data showed that while single APP and PS1 transgene expression did not affect DRL learning and performance, mice expressing double APP/PS1 transgenes were impaired in the acquisition of DRL-10s at 6 months, but not at 3 months of age. The same impaired double transgenic mice, however, were perfectly capable of normal acquisition of signaled DRL-10s (SDRL-10s) task, a hippocampal-independent task, wherein mice were required to emit responses when the end of the 10-second delay was signaled by a lighting of the chamber. The age-dependent and early deficits of APP/PS1 mice suggest that the appetitive DRL paradigm is sensitive to the amyloid pathology present in double APP/PS1 mice, and that this mouse line represents a good model with which to study the efficacy of therapeutic strategies against Alzheimer's disease.

Optimal Cogeneration Technology Selection for Residential and Commercial Buildings

ABSTRACT The energy requirements for most residential and commercial buildings show both annual or seasonal, and daily variations. In addition, depending on the electrical rate schedule and location, there can be time-of-use variation in the prices a customer pays for electricity. Such facts make it harder to select (a) the best-fit equipment for the host building and (b) the best operating strategy for the selected equipment. This article proposes a mixed integer programming (MILP) model to help decide the optimal make up of a prospect cogeneration system as applied to a residential complex located in Zaragoza, Spain. The model considers the possibility of whether to use or not a set of proposed alternative technologies within a previously defined superstructure. Such superstructure is defined through binary variables and takes into account the optimal operation of all feasible combinations of technologies throughout a typical meteorological year. The model's objective function is to minimize the total a...

Optimal time-dependent operation of seawater reverse osmosis

The operation of seawater reverse osmosis (SWRO) plants is systematically optimized with the objective to reduce the electricity charges, which constitute the largest portion of the operation costs. Variable operating conditions and a time-of-use electricity tariff rate schedule are considered. A well-established model is extended to model a reverse osmosis (RO) system equipped with highly efficient pressure exchangers (PXs) and variable frequency drives (VFDs). All major performance factors are considered, including membrane's permeability, concentration polarization, temperature effects, membrane fouling, and efficiency dependency of the VFD on the loading conditions. The proposed formulation minimizes the electricity cost per day, given a desired daily production rate. The problem is formulated as a mixed-integer nonlinear program (MINLP), allowing for periods without operation. The time domain (24 h) is discretized into 0.5 h increments, and a pseudo steady-state assumption is used. The optimal operation plan resulting in maximum electricity cost-savings is established with standard global optimization tools. The results show significant electricity and production cost-saving potentials. More savings in electricity can be achieved by oversizing the plant, thus allowing shutting-off at periods of high electricity cost. The cost-saving potentials are particularly promising in electricity markets in which the electricity rate schedule is widely distributed.

Women's Participation in the NREGA: Some Observations from Fieldwork in Himachal Pradesh, Kerala and Rajasthan

The broad objective of this study was to understand the reasons behind the wide variations in participation by women in the NREGA and the policy implications that follow. Based on fieldwork in two states where women form a high proportion of the workers, Kerala and Rajasthan, and one where the proportion was low, Himachal Pradesh, emerging policy implications include the need to develop a wider range of activities that acknowledge life cycle issues and bodily ability; in sparsely populated and remote areas a different design or even a cash transfer programme may be better able to meet the objective of assuring minimum income; creation of spaces that allow non-governmental local groups to be participants in implementation and outreach work and not just watchdogs; immediate revision of the schedule of rates and implementing the revised rates to allow better earning, or else payment on a daily wage basis.

Performance of Differentiated Rate Scheduling Using Contention-Based CSI Feedback

In this paper, we address the performance of downlink packet delivery under differentiated rate scheduling, where the base station supports different arrival rates to different subsets of users. To reduce the uplink feedback load, the user whose downlink channel gain is larger than a threshold is allowed to send its channel-state information with an access probability through a spread-spectrum-based contention channel. Under this framework, we show that the differentiated rates can be supported among the subsets by adjusting their access probabilities according to their arrival rates. Using large deviation techniques (LDTs), we show that the throughput can be maintained if the performance degradations in the delay and the queue length are allowed for the low-arrival-rate user subset. However, the queue-length performance degradation of the low-rate subset is less severe compared with that of the delay performance. In addition, our simulation results show that the delay performance estimation from LDT analysis is valid even for a delay that is not too large, although it is developed under the assumption of large delay asymptote.

Improving mental state in early imprisonment

Pre-trial prisoners have high rates of mental disorder, but to date, little is known about mental state change or stability among them. The aim of this study was to describe mental state change over the first 4 weeks of imprisonment. Two hundred and fifty-seven new pre-trial male prisoners consented to participate in a prospective interview study. Recruited men tended to be younger than non-recruited men, but otherwise similar. Mental state was assessed 1 and 4 weeks after reception, using the Comprehensive Psychopathological Rating Scale and two self-rating instruments [the 90-item symptom checklist (SCL-90); the Beck Depression Inventory]. After 4 weeks, 170 of the men were still in prison. In their demographics, previous offending, imprisonment, mental health histories or mental health ratings at initial interview, they did not differ from the 87 who were bailed, transferred, sentenced or had their case discontinued. The most sensitive of the rating schedules - the SCL-90 - identified only one new case among the 170 men, but the more illness-specific ratings suggested up to a 10% emergence of new cases by then. By contrast, while two-thirds of the men remained cases according to the SCL-90, about half of the men who had initial interview illness ratings were no longer 'cases'. Measured in terms of 'caseness', distress is likely to be apparent on reception into prison and relatively resistant to change compared with symptoms of mental disorder per se. One-off screening at reception could be misleading. A limitation of our study is that we could measure mental state only twice. A third measure would have clarified whether, in such circumstances, the trend towards improvement is sustained, but brevity of residence in any one prison at this stage tends to preclude this.

Chapter 4: Chemotherapy and radiotherapy

Chapter 4: Chemotherapy and radiotherapy

Income Taxation the New Zealand Minor Beneficiary Regime

The Taxation (Beneficiary Income of Minors, Service-Related Payments and Remedial Matters) Act 2001 taxes the income of most beneficiaries of trusts who are minors at 33 per cent. This measure responded to parents strategically diverting income to their children via trusts, with a view to that income being taxed at the lower rates that children generally enjoy under the progressive schedule of income tax rates. The policy of section HH 3A(1)(a) appears to assume that most children under sixteen who derive income from trusts in fact derive income that would otherwise have gone to their parents, had the parents not sought to minimize tax by diverting their income to their children.There are a number of exceptions to the policy of taxing minor beneficiaries at a flat rate of 33 per cent. The minor beneficiary regime in effect divides trusts into five categories. The author labels the categories “family,” “independent,” “family innocent,” “mixed,” and “mixed innocent,” names that indicate more or less stringent application of the minor beneficiary regime. Each category has rules that address the particular facts.