Successive Occasions Research Articles

Interstock-induced mechanism of increased growth and salt resistance of orange (Citrus sinensis) trees.

Interstocks improve the growth and salt resistance of lemon (Citrus limon (L.) Burm. f.) trees, but their effects on orange (Citrus sinensis (L.) Osbeck) trees are unknown. We grew 'Cleopatra' mandarin (CM) seedlings, budded trees of 'Salustiano' orange (SAO) on CM, 'Valencia Late' orange (VLO) on CM (VLO/CM), and interstock trees VLO/SAO/CM in pots of sand watered with nutrient solution containing 5 (control) or 50 mM NaCl for 12 weeks. Plants were harvested on six successive occasions and the time trends in relative growth rate (RGR) and its components were estimated by fitting a Richards function regression to the harvest data. At low and high salinities, the VLO/SAO/CM combination had higher mean RGR than VLO/CM. Under control conditions, the increase in RGR caused by the interstock was the result of an increase in leaf mass fraction (LMF; leaf dry mass/plant dry mass ratio). Increases in net assimilation rate on a leaf mass basis (NARm) and LMF contributed equally to the increase in RGR in saline conditions, their growth response coefficients being 0.52 and 0.48, respectively. The structural modifications, specific leaf area (SLA) and leaf area ratio (LAR; leaf area:plant dry mass ratio), had a slight influence on the reduction in RGR by salinity. However, NARm had a large influence on RGR, except in CM. The interstock-induced mechanism increased biomass allocation to the assimilatory organs and, under saline conditions, increased Cl- and Na+ allocations to roots. Thus, the flux of ions to the leaves was either delayed or reduced or both. The dilution of imported ions by foliar growth reduced ion concentrations in leaves, resulting in higher NARm, which together with higher LMF, increased RGR.

Effect of an Intensive Glucose Management Protocol on the Mortality of Critically Ill Adult Patients

To assess the effect of an intensive glucose management protocol in a heterogeneous population of critically ill adult patients. This study consisted of 800 consecutive patients admitted after institution of the protocol (treatment group, between February 1, 2003, and January 10, 2004) and 800 patients admitted immediately preceding institution of the protocol (baseline group, between February 23, 2002, and January 31, 2003). The setting was a 14-bed medical-surgical intensive care unit (ICU) in a university-affiliated community teaching hospital. The protocol involved intensive monitoring and treatment to maintain plasma glucose values lower than 140 mg/dL. Continuous intravenous insulin was used if glucose values exceeded 200 mg/dL on 2 successive occasions. The 2 groups of patients were well matched, with similar age, sex, race, prevalence of diabetes mellitus, Acute Physiology and Chronic Health Evaluation II scores, and distribution of diagnoses. After institution of the protocol, the mean glucose value decreased from 152.3 to 130.7 mg/dL (P<.001), marked by a 56.3% reduction in the percentage of glucose values of 200 mg/dL or higher, without a significant change in hypoglycemia. The development of new renal insufficiency decreased 75% (P=-.03), and the number of patients undergoing transfusion of packed red blood cells decreased 18.7% (P=.04). Hospital mortality decreased 29.3% (P=.002), and length of stay in the ICU decreased 10.8% (P=.01). The protocol resulted in significantly improved glycemic control and was associated with decreased mortality, organ dysfunction, and length of stay in the ICU in a heterogeneous population of critically ill adult patients. These results support the adoption of this low-cost intervention as a standard of care for critically ill patients.

Synchytrium endobioticum

<i>Synchytrium endobioticum</i>

The Use of Cell Line Standards to Reduce HER-2/neu Assay Variation in Multiple European Cancer Centers and the Potential of Automated Image Analysis to Provide for More Accurate Cut Points for Predicting Clinical Response to Trastuzumab

Immunohistochemical analysis, the most efficient way of assaying for HER-2/neu overexpression in patients with invasive breast cancer, is subject to variation in sensitivity and evaluation when used in multiple laboratories. Cell lines with differing but constant levels of HER-2/neu expression have been advocated as standard material against which assay sensitivity can be gauged. Automated image analysis could provide more precise linear measurements of HER-2/neu expression than the subjective and categorical scoring system originally designed for the HER-2/neu clinical trials. Multiple European laboratories (range, 92-126) stained 7 cell line standards on 6 successive occasions using a variety of immunohistochemical assays for HER-2/neu. During the 2-year study period, a trend toward a standard sensitivity level was observed, with significant improvement in numbers of laboratories achieving appropriate results. Image analysis gave reproducible and significantly different linear values for a total of 621 HER-2/neu results on cell lines previously categorized manually as 3+, 2+, 1+, or 0. The use of cell line standards and image analysis have the potential to assist in standardizing immunohistochemical results for predictive markers and provide more accurate and quantifiable cut points for predicting clinical response to therapy, respectively.

Modeling Multiple Sources of State Dependence in Random Utility Models: A Distributed Lag Approach

We propose a utility-theoretic brand-choice model that accounts for four different sources of state dependence: 1. effects of lagged choices (structural state dependence), 2. effects of serially correlated error terms in the random utility function (habit persistence type 1), 3. effects of serial correlations between utility-maximizing alternatives on successive purchase occasions of a household (habit persistence type 2), and 4. effects of lagged marketing variables (carryover effects). Our proposed model also allows habit persistence to be a function of lagged marketing variables, while accommodating the effects of unobserved heterogeneity in household choice parameters. This model is more flexible than existing state-dependence models in marketing and labor econometrics. Using scanner panel data, we find structural state dependence to be the most important source of state dependence. Marketing-mix elasticities are systematically understated if state-dependence effects are incompletely accounted for. The Seetharaman and Chintagunta (1998) model is shown to recover spurious variety-seeking effects while overstating habit-persistence effects. Ignoring habit persistence type 1 leads to an underestimation, while ignoring habit persistence type 2 leads to an overestimation of structural state-dependence effects. We find lagged promotions to have carryover effects on habit persistence. Ignoring one or more sources of state dependence underestimates the total incremental impact of a sales promotion. We draw implications for manufacturer pricing.

Assessment of dexmedetomidine/ketamine anesthesia in golden-headed lion tamarins (Leontopithecus chrysomelas)

ObjectiveTo compare the anesthetic and cardiovascular effects of dexmedetomidine/ketamine combinations in golden-headed lion tamarins. Study designProspective blinded randomized study. AnimalsSix healthy golden-headed lion tamarins, three males and three females were studied (mean body weight ± SD = 0.498 ± 0.054 kg). MethodsThe animals were given one of the dexmedetomidine/ketamine combinations (0.005/10, 0.01/10, and 0.01/5 mg kg−1 IM; treatments 5D/10K, 10D/10K, and 10D/5K, respectively) on three successive occasions. Time to sedation and recumbency, as well as anesthesia, standing, and walking times were recorded. Heart and respiratory rate, arterial blood pressure, hemoglobin saturation, and rectal temperature were recorded during anesthesia. Sedation, muscle relaxation, and auditory response were evaluated after drug administration. ResultsHeart rate decreased after two combinations (10D/5K and 10D/10K). Respiratory rate and rectal temperature progressively decreased in all the treatments. Arterial blood pressures were maintained in 5D/10K and 10D/5K treatments and decreased after 10D/10K administration. There were no differences in sedation and recumbency time between the treatments, but anesthesia time was significantly longer in treatment 10D/10K (67.80 ± 13.30 minutes) compared to treatments 10D/5K (44.54 ± 8.25 minutes) and 5D/10K (30.60 ± 6.80 minutes). Standing time was shorter in treatment 10D/10K (11.13 ± 10.01 minutes) than in treatments 5D/10K (18.20 ± 10.03 minutes) and 10D/5K (19.12 ± 14.55 minutes), and walking time was longer in treatment 5D/10K (20.00 ± 12.46 minutes) compared with treatments 10D/10K (16.00 ± 3.43 minutes) and 10D/5K (12.40 ± 5.02 minutes). Anesthetic quality was significantly better 5 and 15 minutes after treatments 10D/10K and 10D/5K than after treatment 5D/10K. Analgesia scores were higher after administration of 10D/10K than after the 5D/10K treatment. Conclusions and clinical relevanceDexmedetomidine/ketamine is useful for chemical immobilization of golden-headed lion tamarins, but bradycardia and hypotension warrant close monitoring.

Treatment of unit non-response in two-stage sampling with partial replacement of units

Three separate estimators, for the estimation of the population total, based on two-stage sampling design on two successive occasions with partial replacement of secondary stage units only have been presented. For these estimators it is assumed that there is unit non-response. Hence, Hansen and Hurwitz (1946) technique has been used to adjust for the non-response. Empirically, it has been found that the estimator that uses individual weights within first stage units perform better than the other estimators that use common weights in estimating the population total. Theoretically, it has also been shown that the larger the ratio of the within first stage unit variability of the non-respondents to the between first stage unit variability the higher the gain in efficiency of the proposed estimators over the estimator obtained when there is no partial matching of units.

Uptake and Distribution of Nitrogen in Perennial Ryegrass: Effect of Additional Applications at Vegetative Growth

Nitrogen (N) fertilization rate, form, and timing in perennial ryegrass (Lolium perenne L.) vary according to the purpose of the grass. Double or triple spring N applications are required in forage production of perennial ryegrass. Whereas in perennial ryegrass grown for seed production the effect of more than one application has not received much attention. The hypothesis is that in perennial ryegrass grown for seed production the utilization of applied N depends on the current N status. Perennial ryegrass was grown in a hydroponic system with two N rates: low‐N (0.2 mM) and high‐N (6.0 mM). After 47 days of growth, additional N was applied as double‐labeled 15NO3 − 15NH4 + on four successive occasions in order to distinguish between the recoveries of the initial N applications and the additional N applied. Growth parameters and N content were analyzed on five harvesting occasions. Additional N applications to plants with low N status were primarily used to increase both N content in all organs as well as shoot number. By contrast, in high‐N treatments, the additional N supplied was primarily used to increase total‐N content in leaves. In all treatments, leaves were the preferable storage organs for N, however, the results from the high‐N treatments suggest a shift to pseudo‐stems as the preferable storage organ when additional N was supplied. It is suggested that the current N concentration in perennial ryegrass determines the potential of the plants to utilize additional applied N.

Die weltweite Bedeutung von permanenten Stichproben im Wandel der Informationsbedürfnisse: das Beispiel der Kohlenstoffinventuren | The global meaning of permanent sampling in keeping with the need for information: the example of carbon stock inventories

Permanent sampling designs utilize permanent plots and observations on successive occasions and proven to be an ideal tool for providing information on the sustainability of timber production. Are permanent sampling designs an adequate instrument to satisfy information needs concerning the sustainability of the multiple functions of forests? The example of carbon stock inventories is selected to demonstrate that permanent sampling designs are flexible instruments for inventorying and monitoring forests. The theoretical concepts of permanent samples can easily be adapted to new attributes and allow for providing a wide scope of information on wood and non-wood goods and services of forests.

Active Versus Passive Loyalty: A Structural Model of Consideration Set Formation

We offer an econometric framework that models a consumer's choice decision as a two-stage process: set formation followed by selection from the brands in the The proposed structural model of set is motivated by the fact that consumers have limited information-acquisition ability. In the context of frequently purchased products (FPPs), since these product categories are characterized by frequent price promotion of varying depths of discount, a faces significant uncertainty about the net utilities associated with the different brands. Thus, while a might know the range of potential prices, she is unaware of the actual posted price of a on any given purchase occasion unless she engages in pre-evaluation price search. Since information acquisition is costly, she needs to first decide how many and which brands to search the posted prices of. In the proposed framework, the process of pre-evaluation price search is conceptualized as brand and the set of sampled brands is referred to as the consumer's consideration set. A distinctive feature of the proposed specification is that it allows us to distinguish between two sources of state dependence - viz., passive and active loyalty. In this conceptualization, passive loyalty refers to state dependence arising out of consumer lock-in as a result of high search cost. Thus, a passively loyal repeatedly buys the same over successive purchase occasions because her cost of searching the posted prices of other brands is very high i.e. her optimal set does not include any other brand. In contrast, active loyalty refers to state dependence arising out of a high intrinsic preference for the selected brand. Thus, while an actively loyal considers more than the selected on any purchase occasion (because her search costs are low), she nonetheless buys the same because of her high intrinsic preference for the brand. Our key theoretical results are as follows: (i) relative to low price sensitive consumers, high price sensitive consumers have larger sets; (ii) the intensity of search is higher in product categories characterized by greater price variability. Thus, more frequent price promotions with deep discounts lead to large sets; and, (iii) a does not stay in the state of inertia for long. In the case of a passively loyal consumer, we will observe phases of inertia followed by a switching that in turn is followed by another spell of inertia. We use scanner panel data for liquid detergents to empirically validate the model. The key empirical results are as follows: (i) there are significant search costs that consumers incur in discovering the actual posted prices of the brands at the store. This implies that consumers do not consider (i.e. search the posted prices of) all the brands on a shopping trip; (ii) in-store display activities and feature ads reduce search costs for a thereby significantly increasing the probability of the being considered. Feature advertising reduces the search costs more than in-store displays; (iii) prior consumption influence quality perception of a for both liquid detergents and ketchup categories. However, consumption experience yield only limited additional quality information; and, (iv) estimates of price sensitivity critically depend on whether the specification explicitly models stage. In particular, a model that assumes that consumers search all the brands on all purchase occasions seriously underestimates the impact of price on choice decision. We also conduct a limited cross-category analysis using ketchup data set and find several interesting differences in price search behavior across the two product categories analyzed.

TTT as rescue treatment for choroidal melanoma not controlled with iodine-125 brachytherapy

Purpose: To describe the use of transpupillary thermotherapy in the management of two small choroidal melanomas that continued to grow following Iodine-125 brachytherapy. Methods: Case reports from a tertiary care center. Results: One small growing choroidal melanoma showed a partial response to Iodine-125 brachytherapy; four years later, it regrew to a thickness of 2.7mm. After transpupillary thermotherapy (TTT), the tumor regressed to a flat scar and has remained inactive for more than three years. A second small melanoma failed to show regression after Iodine-125 brachytherapy; it progressively grew to 3.6mm. TTT was used to treat the tumor on two successive occasions six weeks apart. The tumor regressed to a flat scar within three months and has remained inactive for 2.5 years. Conclusion: TTT may be considered as a rescue treatment for small choroidal melanomas that have failed to respond satisfactorily to brachytherapy.

Anaesthesia with ketamine/medetomidine in the rabbit: influence of route of administration and the effect of combination with butorphanol

ObjectiveTo compare the characteristics of anaesthesia induced with ketamine/medetomidine administered by the subcutaneous and intramuscular routes and to assess the effects of the addition of butorphanol to this combination. Study designProspective randomised study. AnimalsSix female New Zealand White rabbits. MethodsRabbits were given one of four combinations of ketamine and medetomidine (K/M) either subcutaneously (SC) or intramuscularly (IM) on four successive occasions with a 7–day interval between treatments. The dose combinations were; 15/0.25 mg kg−1 SC; 15/0.25 mg kg−1 IM; 15/0.5 mg kg−1 SC, and 15/0.25 mg kg−1 together with 0.4 mg kg−1 butorphanol (K/M/B) SC. The effects of anaesthesia on arterial blood gas values and cardiovascular variables were recorded at predetermined time points. Toe and ear pinch reflexes were judged to determine the duration of surgical anaesthesia. Loss of the righting reflex was used to measure the duration of sleep time. Analyses used repeated measures analysis of variance. ResultsAll groups lost the righting reflex and ear pinch response. Three animals in the groups that received K/M alone lost their toe pinch reflex, whereas four lost this reflex when given K/M/B. Time of onset of loss of the righting, toe and ear pinch reflexes did not differ significantly among the groups. The higher dose combination of medetomidine with ketamine and the combination of K/M/B produced a greater duration of loss of the ear pinch response than the lower dose of K/M administered by either route. No significant differences were found among the groups in the duration of loss of the toe pinch reflex. All animals developed a moderate bradycardia (mean heart rate <166 beats minute−1) and moderate hypoxaemia (mean PaO2 < 6.0 kPa). Animals given butorphanol showed the greatest reduction in respiratory rate (31 ± 13 breaths minute−1, p < 0.05) but this was not reflected in any significant differences in arterial PCO2, PO2 or pH among the groups. ConclusionsAdministration of K/M by the SC route produced equivalent effects in comparison to intramuscular administration. The addition of butorphanol increased the duration of anaesthesia, but produced a slight increase in the degree of respiratory depression. All dose rates resulted in hypoxaemia so oxygen should be administered when these combinations are used in rabbits. Clinical relevanceSubcutaneous administration is both technically simpler and may cause less discomfort to the animal than IM injection, and so is preferred. The combination of K/M with butorphanol has relatively minor effects on the depth and duration of anaesthesia, so offers little advantage to the use of K/M alone.

What conservation anticipation reveals about cognitive change

A long-running debate about the nature of the thinking involved in conservation judgments resulted in postulating the existence of two different processes. According to the pluralist approach to cognitive development, the two processes can be simultaneously activated with different weights for different children and are likely to interact. A semi-longitudinal study that tests the pluralist approach is reported. The experimental procedure was based on earlier work by Acredolo and Acredolo (1979, 1980). Children from the last year of nursery school (mean age: 5 years and 6 months) were individually tested in two successive occasions separated by a 3-month interval. The first test occasion consisted of a sequence of liquid-conservation-anticipation and level anticipation tasks. This same sequence was reproduced during the second test occasion, which ended with a classical conservation task. Observed patterns of correct-incorrect answers contradict the predictions of a developmental sequence assumed by the Piagetian model. The patterns of change were compatible with a pluralist approach which hypothesizes different routes in the development of conservation.

Modern Interactionism

Modern Interactionism

Successive Sampling Using Auxiliary Information on Both the Occasions

In successive sampling with partial replacement, an estimator is proposed for the population mean on the second of two successive occasions utilising information available on both the occasions on an auxiliary variate with an unknown population mean. It is shown that the proposed estimator is more efficient than the sample mean and the estimators considered by Sen (1971). An empirical study is also included.

Treatment of non-response in successive sampling

Estimators of the population mean have been presented for sampling on two successive occasions when there is non-response in the sample. These estimators have been derived using the Hansen and Hurwitz (1946) procedure for treating non-response. The estimators were found to be more efficient than the Hansen-Hurwitz estimator.

Phonology constrains the internal orthographic representation

Four experiments explored the composition and stability of internalorthographic representations of printed words. In three experiments,subjects were presented on successive occasions with words that wereconsistently spelled correctly or were consistently misspelled. On thesecond presentation, subjects were more likely to judge both kinds ofwords as correctly spelled than on the first presentation, suggesting thattheir preexperimental orthographic representations had been altered tomatch what they had seen on the first presentation. However, onlymisspellings that were consistent with the correct phonology wereaccepted; spellings that altered the phonology were rarely accepted,suggesting that some parts of the orthographic representation are lessstable than others. Also, subjects' reliance on orthographic vs.phonological memory when judging a word's spelling was affected by thekinds of other misspellings in the list. Lists that contained somephonologically implausible spellings for real words (e.g., *assostance)induced subjects to rely more on phonological plausibility when judgingthe correctness of other words in the list and less on orthographic memory.An individual grapheme in an internal orthographic representation wasunstable when there were many phonologically acceptable alternatives forit. The results are contrary to the view that the strength of an internalrepresentation is uniform across all its graphemes and is a function only ofvisual experience with the printed form. Results were interpreted in thecontext of a theory that considers spelling knowledge to be a by-productof the reading process, a process that involves phonological analysis.

Associations between infections and fatigue in a Dutch working population: results of the Maastricht Cohort Study on Fatigue at Work.

The relationship between fatigue and common infections was further explored, as part of a 3 year prospective cohort study on Fatigue at Work. The current study is based on seven successive questionnaires, covering the first 2 years of follow-up. The overall response at baseline was 45% (n = 12,140). On T1 10,592 (87.2% compared to baseline response) employees returned the questionnaire. For T2, T3, T4, T5 and T6, 10,270 (84.6%), 9655 (79.5%), 8956 (73.8%), 8692 (71.6%) and 8070 (66.5%) employees respectively returned the questionnaire. Self-administered questionnaires were used to determine the level of fatigue with the Checklist Individual Strength (CIS) and the occurrence of common cold, flu-like illness and gastroenteritis. Regression analysis using generalized estimated equations (GEE) were used for data analysis. We found a cross-sectional relationship between fatigue and the infections flu-like illness and gastroenteritis, and a longitudinal relationship between an infection as a predictor of fatigue. For fatigue as a predictor of an infection, we found odds ratios (ORs) of 1.35 (confidence interval (CI) 1.28-1.42) for flu-like illness and 1.33 (CI: 1.25-1.42) for gastroenteritis. The highest incidence of infections was found among employees who reported high fatigue levels on two successive occasions. The increased incidence of infections, is regarded as a substantial effect of fatigue because it is associated with significant absenteeism from work and leads to discomfort.

Assessment of ketamine/medetomidine anaesthesia in the New Zealand White rabbit

ObjectiveTo compare the characteristics of anaesthesia induced with four dose combinations of ketamine/medetomidine. DesignProspective randomized study.Animals Five female New Zealand White (NZW) rabbits of approximately 2.3 kg. MethodsRabbits were given one of four drug combinations (25/0.25; 15/0.5; 15/0.25 and 10/0.5 mg kg−1 IM) on four successive occasions with a four day interval. Response to injection and then arterial blood gas and cardiovascular parameters were recorded at predetermined time points. Toe and ear pinch reflexes gave measures of total duration of surgical anaesthesia and total sleep time. Analyses used repeated measures analysis of variance. ResultsInduction was smooth with little reaction to injection and intubation achieved easily. Two combinations (15/0.25, 10/0.5) produced moderate hypoxaemia (mean pO2 < 8.0 kPa) and two (25/0.25, 15/0.5) very marked hypoxaemia (mean pO2 < 5.3 kPa). This was reversed within 15 minutes of oxygen administration and all rabbits recovered uneventfully. Heart rates fell in all cases, with only minimal effects on arterial blood pressure and no cardiac arrhythmias. Mean duration of surgical anaesthesia was significantly longer for dose groups 25/0.25 (57 ± 12 minutes) and 15/0.5 (59 ± 17 minutes, p = 0.01) compared to dose group 15/0.25 (27 ± 8 minutes). Only three animals in the 10/0.5 mg kg−1 group achieved surgical anaesthesia. Mean duration of loss of the ear pinch reflex was similar between doses, being, respectively, 64 ± 13, 81 ± 7, 60 ± 22 and 62 ± 24 minutes. Sleep time was significantly longer for the 15/0.5 dose (112 ± 10 minutes) compared to 15/0.25 (86 ± 22 minutes, p = 0.04). Sleep times for the 25/0.25 and 10/0.5 mg kg−1 doses were, respectively, 103 ± 23 and 108 ± 12 minutes. ConclusionsKetamine/medetomidine reliably produces smooth induction and recovery in the NZW rabbit, but due to the degree of hypoxaemia produced, should only be used with simultaneous provision of oxygen. Clinical relevanceCurrently recommended dose rates of ketamine/medetomidine for minor procedures such as ovariohysterectomy in rabbits (25 mg/0.5 mg kg−1) are unnecessarily high; a dose of 15/0.25 mg kg−1 should be adequate for 15–30 minutes of surgical anaesthesia.

PUERTO RICO AND U.S. MAINLAND SCHOOLS: EFFECTS OF MIGRATION AND LINGUISTIC SEGREGATION ON CHILDREN'S ENGLISH-LANGUAGE DEVELOPMENT

Using a longitudinal research design with multiple migration waves and grade cohorts, this study examined the effects of migration and of school segregation by native language on the English-language development of Spanish-speaking students. Participants were 231 normal children who arrived from Puerto Rico in 67 U.S. mainland (New Jersey) elementary schools. Each child's English-language proficiency was tested initially at arrival from Puerto Rico, using the Language Assessment Battery (listening, reading, writing, and speaking tests), and twice again in the course of two academic years, even during returns to Puerto Rico. The student body of each mainland school that the participants attended during their longitudinal span was measured for linguistic composition and, for statistical control, economic poverty level. As hypothesized, participants' English proficiency developed more slowly in schools in which student bodies had relatively high percentages of native speakers of Spanish, faster in schools in which student bodies had relatively high percentages of monolingual native speakers of English (p < .03). Although participants' English-proficiency raw scores generally increased substantially between successive longitudinal occasions, the grade-level percentile ranks (derived from U.S. norms for native speakers of English) for these scores increased very little—a probably frustrating contrast between absolute and relative achievement. Participants who returned to schools in Puerto Rico continued to develop their English-language proficiency, although considerably more slowly than during their stay in stateside schools.