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Background While the use of stimulant medication as a treatment for children with attention deficit hyperactivity disorder (ADHD) has been the most studied therapy in child psychiatry, there is debate about its use with young children. This study describes a series of cases seen in a normal clinical context, treated with one of four different treatment programmes. Methods Sixteen pre-school children diagnosed with ADHD and their parents were randomly assigned to receive one of four treatments: (1) 0.3 mg/kg methylphenidate, parent training programme; (2) 0.3 mg/kg methylphenidate, parent support programme; (3) placebo medication, parent training; and (4) placebo medication, parent support. Changes were assessed at the individual level, using clinical observations, parent and teacher rating scales and measures of parenting and family factors. Results Children were more likely to improve when the treatment involved at least one active component (medication or parent training). However, there was notable variability in individual parental and child participants' responses to all treatment conditions, indicating the importance of interactions between treatment variables and other factors. Conclusions Findings are discussed within the framework of a transactional model, and inferences are drawn about the limitations of the idea that there is a 'best treatment' that is universally applicable. [ABSTRACT FROM AUTHOR]

Blueberry has a diversity of anthocyanins that confer its characteristic, blue-coloured skin. Whilst most cultivars produce only anthocyanin glycosides, some can add aliphatic or aromatic groups to the sugar moiety to create acylated anthocyanins. Due to their enhanced stability, acylated anthocyanins represent an attractive breeding target in blueberry. In this study a haplotype-resolved assembly of a previously identified quantitative trait locus on chromosome 2 of 'Hortblue Petite' (Vaccinium corymbosum) was created to identify candidate anthocyanin acyltransferase genes. One full-length gene (VcAAT1a) was selected, based on qPCR expression profiling and transient expression in tobacco leaves and strawberry and blueberry fruit flesh. In all three systems VcAAT1a was able to produce a range of acylated anthocyanins in plantae. Recombinant VcAAT1a protein demonstrated that, while VcAAT1a was able to act on both anthocyanin 3-O-glucosides and 3-O-galactosides, it could only utilise acetyl CoA as an acyl donor. Protein modelling using AlphaFold suggested that this restricted range in acyl donors may be due to a spatially restricted sub-pocket in the acyl binding site of VvAAT1. Finally, LUC/REN promoter activation assays revealed that the VcAAT1a promoter was transactivated by the VcMYBPA1 and VcMYBPA2 transcription factors, further expanding our knowledge of anthocyanin regulation in blueberry., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Experimental Biology.)

A 9-year-old, female spayed domestic short-haired cat was presented with a 4-year history of bilateral lipogranulomatous conjunctivitis (LGC), which was confirmed via histopathology. Thirteen months following the initial biopsy, the cat was presented with a rapidly progressive mass lesion of the palpebral conjunctiva of the right eye. A surgical debulking, followed 1 month later by exenteration after marked regrowth of the mass confirmed fibrosarcoma. This case report is the first to describe a cat with chronic bilateral LGC that later developed a unilateral fibrosarcoma within the eyelid tissue of the right eye. Fibrosarcoma should be considered a differential in any cat with chronic LGC that develops a rapidly progressive mass in the eyelid., (© 2024 The Author(s). Veterinary Ophthalmology published by Wiley Periodicals LLC on behalf of American College of Veterinary Ophthalmologists.)

Nitrogen is an essential nutrient for plant growth and serves as a signaling molecule to regulate gene expression inducing physiological, growth and developmental responses. An excess or deficiency of nitrogen may have adverse effects on plants. Studying nitrogen uptake will help us understand the molecular mechanisms of utilization for targeted molecular breeding. Here, we identified and functionally validated an NAC (NAM-ATAF1/2-CUC2) transcription factor based on the transcriptomes of two apple rootstocks with different nitrogen uptake efficiency. NAC1, a target gene of miR164, directly regulates the expression of the high-affinity nitrate transporter (MhNRT2.4) and citric acid transporter (MhMATE), affecting root nitrogen uptake. To examine the role of MhNAC1 in nitrogen uptake, we produced transgenic lines that overexpressed or silenced MhNAC1. Silencing MhNAC1 promoted nitrogen uptake and citric acid secretion in roots, and enhanced plant tolerance to low nitrogen conditions, while overexpression of MhNAC1 or silencing miR164 had the opposite effect. This study not only revealed the role of the miR164-MhNAC1 module in nitrogen uptake in apple rootstocks but also confirmed that citric acid secretion in roots affected nitrogen uptake, which provides a research basis for efficient nitrogen utilization and molecular breeding in apple., (© 2024 The Authors. New Phytologist © 2024 New Phytologist Foundation.)

Dwarfing rootstocks have transformed the production of cultivated apples; however, the genetic basis of rootstock-induced dwarfing remains largely unclear. We have assembled chromosome-level, near-gapless and haplotype-resolved genomes for the popular dwarfing rootstock 'M9', the semi-vigorous rootstock 'MM106' and 'Fuji', one of the most commonly grown apple cultivars. The apple orthologue of auxin response factor 3 (MdARF3) is in the Dw1 region of 'M9', the major locus for rootstock-induced dwarfing. Comparing 'M9' and 'MM106' genomes revealed a 9,723-bp allele-specific long terminal repeat retrotransposon/gypsy insertion, DwTE, located upstream of MdARF3. DwTE is cosegregated with the dwarfing trait in two segregating populations, suggesting its prospective utility in future dwarfing rootstock breeding. In addition, our pipeline discovered mobile mRNAs that may contribute to the development of dwarfed scion architecture. Our research provides valuable genomic resources and applicable methodology, which have the potential to accelerate breeding dwarfing rootstocks for apple and other perennial woody fruit trees., (© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Background: Protein-truncating germline pathogenic variants in the N- and C-terminal exons (2, 9, and 10) of the MEN1 gene may be associated with aggressive pancreatic neuroendocrine tumors. However, the impact of these variants on parathyroid disease is poorly understood. We sought to investigate the effects of genotype and surgical approach on clinical phenotype and postoperative outcomes in patients with multiple endocrine neoplasia type 1 (MEN1)-related primary hyperparathyroidism., Methods: We identified patients with MEN1 evaluated at our institution from 1985 to 2020 and stratified them by genotype, (truncating variants in exons 2, 9, or 10, or other variants), and index surgical approach, (less-than-subtotal parathyroidectomy [

In grafted apple, rootstock-derived signals influence scion cold tolerance by initiating physiological changes to survive over the winter. To understand the underlying molecular interactions between scion and rootstock responsive to cold, we developed transcriptomics and metabolomics data in the stems of two scion/rootstock combinations, 'Gala'/'G202' (cold resistant rootstock) and 'Gala'/'M9' (cold susceptible rootstock). Outer layers of scion and rootstock stem, including vascular tissues, were collected from the field-grown grafted apple during the winter. The clustering of differentially expressed genes (DEGs) and gene ontology enrichment indicated distinct expression dynamics in the two graft combinations, which supports the dependency of scion cold tolerance on the rootstock genotypes. We identified 544 potentially mobile mRNAs of DEGs showing highly-correlated seasonal dynamics between scion and rootstock. The mobility of a subset of 544 mRNAs was validated by translocated genome-wide variants and the measurements of selected RNA mobility in tobacco and Arabidopsis. We detected orthologous genes of potentially mobile mRNAs in Arabidopsis thaliana, which belong to cold regulatory networks with RNA mobility. Together, our study provides a comprehensive insight into gene interactions and signal exchange between scion and rootstock responsive to cold. This will serve for future research to enhance cold tolerance of grafted tree crops., (© 2023. The Author(s).)

Differential reinforcement of alternative behavior (DRA) involves placing problem behavior under extinction and simultaneously reinforcing a desirable behavior. Recent research revealed that, as predicted by Behavioral Momentum Theory, DRA may also increase the persistence of the problem behavior. This research has also shown that a different approach to DRA, in which an alternative behavior is trained in a separate context from the target behavior, produces less persistence than the standard procedure. The research on this phenomenon, so far, assessed persistence using extinction as the disruptor. DRA, however, is often implemented under conditions in which extinction of the problem behavior is not feasible. This study evaluated persistence of problem behavior following same- and separate- context DRA training using an alternative disruptor, an additional source of reinforcement. Following a successful reproduction of a previous study of extinction as a disruptor but with domestic hens, this study produced similar findings using an additional source of reinforcement as the disruptor. These findings add to the evidence that alternative DRA arrangements may avoid the response-strengthening effects found with traditional DRA procedures. The findings also demonstrate that disruptors other than extinction can be used to investigate response persistence following DRA and other procedures., (© 2022 The Authors. Journal of the Experimental Analysis of Behavior published by Wiley Periodicals LLC on behalf of Society for the Experimental Analysis of Behavior.)

Commercially grown kiwifruit (genus Actinidia) are generally of two sub-species which have a base haploid genome of 29 chromosomes. The yellow-fleshed Actinidia chinensis var. chinensis, is either diploid (2n = 2x = 58) or tetraploid (2n = 4x = 116) and the green-fleshed cultivar A. chinensis var. deliciosa "Hayward," is hexaploid (2n = 6x = 174). Advances in breeding green kiwifruit could be greatly sped up by the use of molecular resources for more efficient and faster selection, for example using marker-assisted selection (MAS). The key genetic marker that has been implemented for MAS in hexaploid kiwifruit is for gender testing. The limited marker-trait association has been reported for other polyploid kiwifruit for fruit and production traits. We have constructed a high-density linkage map for hexaploid green kiwifruit using genotyping-by-sequence (GBS). The linkage map obtained consists of 3686 and 3940 markers organized in 183 and 176 linkage groups for the female and male parents, respectively. Both parental linkage maps are co-linear with the A. chinensis "Red5" reference genome of kiwifruit. The linkage map was then used for quantitative trait locus (QTL) mapping, and successfully identified QTLs for king flower number, fruit number and weight, dry matter accumulation, and storage firmness. These are the first QTLs to be reported and discovered for complex traits in hexaploid kiwifruit., (© The Author(s) 2021. Published by Oxford University Press on behalf of Genetics Society of America.)

Researchers have employed a variety of laboratory analogues of cryptic prey detection and applied signal detection to study factors influencing learning and performance in these ethological and applied scenarios. However, these procedural analogues do not appear to map closely onto their "real-world" counterparts, particularly with respect to the role of the "yes" (i.e., "attack") response and the payoff for this response (or its absence) on signal-present and signal-absent trials. Using domestic hens, we developed a procedural analogue in which a "yes" response requires some time to emit; such responses were reinforced only in the presence of a signal. In Experiment 1, we evaluated the influence of the "yes" response requirement by manipulating the number of responses required to qualify as a "yes" response. As the "yes" response requirement was increased, bias toward responding "no" increased, revealing that this is a critical factor controlling accuracy in this procedure. In Experiment 2, we evaluated the influence of signal probability and reinforcement rate on signal detection accuracy and found that neither of these factors significantly influenced accuracy or bias. These findings suggest that this procedural analogue may represent a valuable alternative for studying behaviour in relevant signal detection scenarios., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Prospective memory is remembering to carry out a behavior on a particular occasion or at a specific time in the future. This form of remembering is critical for the daily functioning of children with autism spectrum disorder (ASD) and their functional independence from caregivers. We used a single-subject design to investigate whether reinforcement increased the accuracy of prospective remembering in the context of a computerized board game, Virtual Week, of four 6- to 7-year-old children diagnosed with ASD. Reinforcement increased accuracy for all participants compared to baseline performance and effects were maintained after reinforcement was discontinued for three of four children. This is the first study of which we are aware to use a reinforcement-based behavioral intervention to improve the prospective remembering of children with ASD. Limitations and areas for future research are discussed., (© 2019 Society for the Experimental Analysis of Behavior.)

Most Rubus species have a biennial cycle of flowering and fruiting with an intervening period of winter dormancy, in common with many perennial fruit crops. Annual-fruiting (AF) varieties of raspberry ( Rubus idaeus and Rubus occidentalis L.) and blackberry ( Rubus subgenus Rubus ) are able to flower and fruit in one growing season, without the intervening dormant period normally required in biennial-fruiting (BF) varieties. We used a red raspberry ( R. idaeus ) population segregating for AF obtained from a cross between NC493 and 'Chilliwack' to identify genetic factors controlling AF. Genotyping by sequencing (GBS) was used to generate saturated linkage maps in both parents. Trait mapping in this population indicated that AF is controlled by two newly identified loci ( RiAF3 and RiAF4 ) located on Rubus linkage groups (LGs) 3 and 4. The location of these loci was analyzed using single-nucleotide polymorphism (SNP) markers on independent red raspberry and blackberry populations segregating for the AF trait. This confirmed that AF in Rubus is regulated by loci on LG 3 and 4, in addition to a previously reported locus on LG 7. Comparative RNAseq analysis at the time of floral bud differentiation in an AF and a BF variety revealed candidate genes potentially regulating the trait., (Copyright © 2019 Jibran, Spencer, Fernandez, Monfort, Mnejja, Dzierzon, Tahir, Davies, Chagné and Foster.)

Rubus fruits are high-value crops that are sought after by consumers for their flavor, visual appeal, and health benefits. To meet this demand, production of red and black raspberries ( R. idaeus L. and R. occidentalis L.), blackberries ( R . subgenus Rubus ), and hybrids, such as Boysenberry and marionberry, is growing worldwide. Rubus breeding programmes are continually striving to improve flavor, texture, machine harvestability, and yield, provide pest and disease resistance, improve storage and processing properties, and optimize fruits and plants for different production and harvest systems. Breeders face numerous challenges, such as polyploidy, the lack of genetic diversity in many of the elite cultivars, and until recently, the relative shortage of genetic and genomic resources available for Rubus . This review will highlight the development of continually improving genetic maps, the identification of Quantitative Trait Loci (QTL)s controlling key traits, draft genomes for red and black raspberry, and efforts to improve gene models. The development of genetic maps and markers, the molecular characterization of wild species and germplasm, and high-throughput genotyping platforms will expedite breeding of improved cultivars. Fully sequenced genomes and accurate gene models facilitate identification of genes underlying traits of interest and enable gene editing technologies such as CRISPR/Cas9., Competing Interests: Conflict of interestThe authors declare that they have no conflict of interest., (© The Author(s) 2019.)

This study evaluated the ability of Killeen's (1994) Mathematical Principles of Reinforcement to account for the effects of changes in reinforcer quality on hens' rates of responding on fixed-ratio schedules. Hens were trained to peck a key on a fixed-ratio schedule of reinforcement and then experienced an ascending series of ratio values in two separate conditions. In different conditions, the food reinforcer was either wheat or puffed wheat. Response rates initially increased with increases in ratio requirement before eventually decreasing at larger ratios. Quantitative fits of the model accounted for the data well. The fits revealed that different foods were systematically associated with changes in the specific activation parameter, a, and these were consistent with previous reports of preference for those food items., (© 2019 Society for the Experimental Analysis of Behavior.)

A bud sport is a lateral shoot, inflorescence or single flower/fruit with a visibly different phenotype from the rest of the plant. The new phenotype is often caused by a stable somatic mutation in a single cell that is passed on to its clonal descendants and eventually populates part or all of a meristem. In many cases, a bud sport can be vegetatively propagated, thereby preserving the novel phenotype without sexual reproduction. Bud sports provide new characteristics while retaining the desirable qualities of the parent plant, which is why many bud sports have been developed into popular cultivars. We present an overview of the history of bud sports, the causes and methods of detecting somaclonal variation, and the types of mutant phenotypes that have arisen spontaneously. We focus on examples where the molecular or cytological changes causing the phenotype have been identified. Analysis of these sports has provided valuable insight into developmental processes, gene function and regulation, and in some cases has revealed new information about layer-specific roles of some genes. Examination of the molecular changes causing a phenotype and in some cases reversion back to the original state has contributed to our understanding of the mechanisms that drive genomic evolution., Competing Interests: The authors declare that they have no conflict of interest.

Branching has a major influence on the overall shape and productivity of a plant. Strigolactones (SLs) have been identified as plant hormones that have a key role in suppressing the outgrowth of axillary meristems. CAROTENOID CLEAVAGE DIOXYGENASE (CCD) genes are integral to the biosynthesis of SLs and are well characterized in annual plants, but their role in woody perennials is relatively unknown. We identified CCD7 and CCD8 orthologues from apple and demonstrated that MdCCD7 and MdCCD8 are able to complement the Arabidopsis branching mutants max3 and max4 respectively, indicating conserved function. RNAi lines of MdCCD7 show reduced gene expression and increased branching in apple. We performed reciprocal grafting experiments with combinations of MdCCD7 RNAi and wild-type 'Royal Gala' as rootstocks and scion. Unexpectedly, wild-type roots were unable to suppress branching in MdCCD7 RNAi scions. Another key finding was that MdCCD7 RNAi scions initiated phytomers at an increased rate relative to the wild type, resulting in a greater node number and primary shoot length. We suggest that localized SL biosynthesis in the shoot, rather than roots, controls axillary bud outgrowth and shoot growth rate in apple.

Background: Most published genome sequences are drafts, and most are dominated by computational gene prediction. Draft genomes typically incorporate considerable sequence data that are not assigned to chromosomes, and predicted genes without quality confidence measures. The current Actinidia chinensis (kiwifruit) 'Hongyang' draft genome has 164 Mb of sequences unassigned to pseudo-chromosomes, and omissions have been identified in the gene models., Results: A second genome of an A. chinensis (genotype Red5) was fully sequenced. This new sequence resulted in a 554.0 Mb assembly with all but 6 Mb assigned to pseudo-chromosomes. Pseudo-chromosomal comparisons showed a considerable number of translocation events have occurred following a whole genome duplication (WGD) event some consistent with centromeric Robertsonian-like translocations. RNA sequencing data from 12 tissues and ab initio analysis informed a genome-wide manual annotation, using the WebApollo tool. In total, 33,044 gene loci represented by 33,123 isoforms were identified, named and tagged for quality of evidential support. Of these 3114 (9.4%) were identical to a protein within 'Hongyang' The Kiwifruit Information Resource (KIR v2). Some proportion of the differences will be varietal polymorphisms. However, as most computationally predicted Red5 models required manual re-annotation this proportion is expected to be small. The quality of the new gene models was tested by fully sequencing 550 cloned 'Hort16A' cDNAs and comparing with the predicted protein models for Red5 and both the original 'Hongyang' assembly and the revised annotation from KIR v2. Only 48.9% and 63.5% of the cDNAs had a match with 90% identity or better to the original and revised 'Hongyang' annotation, respectively, compared with 90.9% to the Red5 models., Conclusions: Our study highlights the need to take a cautious approach to draft genomes and computationally predicted genes. Our use of the manual annotation tool WebApollo facilitated manual checking and correction of gene models enabling improvement of computational prediction. This utility was especially relevant for certain types of gene families such as the EXPANSIN like genes. Finally, this high quality gene set will supply the kiwifruit and general plant community with a new tool for genomics and other comparative analysis.

Black raspberry ( Rubus occidentalis L.) is a niche fruit crop valued for its flavor and potential health benefits. The improvement of fruit and cane characteristics via molecular breeding technologies has been hindered by the lack of a high-quality reference genome. The recently released draft genome for black raspberry (ORUS 4115-3) lacks assembly of scaffolds to chromosome scale. We used high-throughput chromatin conformation capture (Hi-C) and Proximity-Guided Assembly (PGA) to cluster and order 9650 out of 11,936 contigs of this draft genome assembly into seven pseudo-chromosomes. The seven pseudo-chromosomes cover ~97.2% of the total contig length (~223.8 Mb). Locating existing genetic markers on the physical map resolved multiple discrepancies in marker order on the genetic map. Centromeric regions were inferred from recombination frequencies of genetic markers, alignment of 303 bp centromeric sequence with the PGA, and heat map showing the physical contact matrix over the entire genome. We demonstrate a high degree of synteny between each of the seven chromosomes of black raspberry and a high-quality reference genome for strawberry ( Fragaria vesca L.) assembled using only PacBio long-read sequences. We conclude that PGA is a cost-effective and rapid method of generating chromosome-scale assemblies from Illumina short-read sequencing data., Competing Interests: The authors declare that they have no conflict of interest.

Hens responded under multiple fixed-ratio schedules with equal response requirements and either a 1-s or a 6-s reinforcer. Upcoming reinforcer size was indicated by key color. Components were presented in a quasirandom series so that all four component transitions occurred. Postreinforcement pauses were affected by the upcoming and preceding reinforcer size, with longer pauses after large reinforcers followed by small reinforcers than when followed by large ones, and longer pauses after small reinforcers that were followed by small reinforcers rather than large ones. Pauses increased with fixed-ratio size and the effects of reinforcer size were larger the larger the ratio. When reinforcer size was not signaled-mixed fixed-ratio schedules-pauses were shorter after small than after large reinforcers. Signalling the upcoming reinforcer attenuated the effect of the previous reinforcer size on pause duration when small was followed by small and when either small or large by large, but enhanced the effect when large was followed by small. There was no effect of reinforcer size on pause duration when single fixed-ratio schedules were arranged. The effects of reinforcer size on pauses depends on the size and range of the fixed ratios as well as the exact procedures used in the study., (© 2017 Society for the Experimental Analysis of Behavior.)

Apple dwarfing rootstocks cause earlier shoot termination and reduced root and shoot mass. To identify physiological factors responsible for rootstock-induced growth restriction, we compared vascular-enriched gene expression between two dwarfing rootstocks ('M27' and 'M9') and the vigorous rootstock 'M793' using RNA sequencing and quantitative reverse transcriptase PCR. Differentially expressed genes common to both dwarfing rootstocks belonged to five main biological processes: (1) primary metabolism, (2) cell wall synthesis and modification, (3) secondary metabolism, (4) hormone signalling and response and (5) redox homeostasis. Genes promoting the biosynthesis of amino acids, lipids and cell walls were downregulated in dwarfing rootstocks, whereas genes promoting the breakdown of these compounds were upregulated. The only exception to this trend was the upregulation of starch synthesis genes in dwarfing rootstocks. Non-structural carbohydrate analysis demonstrated that starch concentrations in 'M9' roots, stems and grafted 'Royal Gala' ('RG') scions were double that of equivalent tissues from 'RG' homo-grafted trees ('RG'/'RG'). Fructose and glucose concentrations were much lower in all three tissues of the 'RG'/'M9' trees. Together, these data indicate that dwarfing rootstocks are in a state of sugar depletion and reduced cellular activity despite having large starch reserves. Another significant finding was the over-accumulation of flavonoids and the downregulation of auxin influx transporters MdAUX1 and MdLAX2 in dwarfing rootstocks. We propose that both factors reduce polar auxin transport. The results of this study contribute novel information about the physiological state of dwarfing rootstocks., Competing Interests: The authors declare no conflict of interest.

In a replication of Reynolds (1961), two cows learned to discriminate between compound stimuli in a forced choice procedure where pushing through a one-way gate marked with a red cross (S+) gave access to food. Pushing through a one-way gate marked with a yellow triangle (S-) gave no access to food. To investigate whether shape or colour was controlling behaviour, probe tests varied either the shape or the colour of the stimuli (e.g., a red vs. a yellow cross, and a red cross vs. a red triangle). Results suggested control by colour rather than shape, as the gate marked with the red stimulus was chosen more than the gate marked with the yellow stimulus regardless of stimulus shape, and when two shapes of the same colour (either red or yellow) were presented, cows chose both equally. Further probe tests with painted red, white, and yellow stimuli showed that the cows had learned to avoid yellow rather than to approach red, suggesting discriminative behaviour was controlled by the colour of the negative stimulus and not by either aspect of the positive stimulus. It is not clear why the negative stimulus was more salient, but it may reflect a tendency for cows to learn to avoid farm handling practices which involve mainly negative stimuli., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The apple dwarfing rootstock 'Malling9' ('M9') has been used worldwide both to reduce scion vigour and as a genetic source for breeding new rootstocks. Progeny of 'M9' segregate for rootstock-induced dwarfing of the scion, indicating that this trait is controlled by one or more genetic factors. A quantitative trait locus (QTL) analysis of a rootstock population derived from the cross between 'M9' × 'Robusta5' (non-dwarfing) and grafted with 'Braeburn' scions identified a major QTL (Dw1) on linkage group (LG) 5, which exhibits a significant influence on dwarfing of the scion. A smaller-effect QTL affecting dwarfing (Dw2) was identified on LG11, and four minor-effect QTLs were found on LG6, LG9, LG10 and LG12. Phenotypic analysis indicates that the combination of Dw1 and Dw2 has the strongest influence on rootstock-induced dwarfing, and that Dw1 has a stronger effect than Dw2. Genetic markers linked to Dw1 and Dw2 were screened over 41 rootstock accessions that confer a range of effects on scion growth. The majority of the dwarfing and semi-dwarfing rootstock accessions screened carried marker alleles linked to Dw1 and Dw2. This suggests that most apple dwarfing rootstocks have been derived from the same genetic source.

Two experiments examined whether hens, Gallus gallus domesticus, would respond to photographs in the same way they do to the real objects depicted in the photographs. Experiment 1 assessed whether hens transferred a discrimination of differently coloured three-dimensional objects to two-dimensional photographs of those objects, and vice versa. All hens learned to discriminate between the stimuli and showed transfer to the alternative stimuli when the colour cues were present. In Experiment 2 transfer with stimuli that differed in shape only was examined. It was found that only three of the six hens learned to discriminate the stimuli to any degree, and that these three hens did not transfer this discrimination to the alternative stimuli. It was also found that previously learning an object discrimination did not aid the hens in learning to discriminate between photographs of the objects. These data suggest that the hens did not respond to the objects depicted in pictures in the same way they did to the real objects. The authors argue it cannot be assumed that all animals respond to two-dimensional pictures of stimuli in the same way as they do to the real three-dimensional stimuli and this should be established before researchers use two-dimensional stimuli as representatives of real world stimuli., (Copyright © 2014 Elsevier B.V. All rights reserved.)

This study compared three methods of normalizing demand functions to allow comparison of demand for different commodities and examined how varying reinforcer magnitudes affected these analyses. Hens responded under fixed-ratio schedules in 40-min sessions with response requirement doubling each session and with 2-s, 8-s, and 12-s access to wheat. Over the smaller fixed ratios overall response rates generally increased and were higher the shorter the magazine duration. The logarithms of the number of reinforcers obtained (consumption) and the fixed ratio (price) were well fitted by curvilinear demand functions (Hursh et al., 1988. Journal of the Experimental Analysis of Behavior 50, 419-440) that were inelastic (b negative) over small fixed-ratios. The fixed ratio with maximal response rate (Pmax) increased, and the rate of change of elasticity (a) and initial consumption (L) decreased with increased magazine duration. Normalizing consumption using measures of preference for various magazine durations (3-s vs. 3-s, 2-s vs. 8-s, and 2-s vs. 12-s), obtained using concurrent schedules, gave useful results as it removed the differences in L. Normalizing consumption and price (Hursh and Winger, 1995. Journal of the Experimental Analysis of Behavior 64, 373-384) unified the data functions as intended by that analysis. The exponential function (Hursh and Silberberg, 2008. Psychological Review, 115, 186-198) gave an essential value that increased (i.e., α decreased significantly) as magazine duration decreased. This was not as predicted, since α should be constant over variations in magazine duration, but is similar to previous findings using a similar procedure with different food qualities (hens) and food quantities (rats)., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Domestic hens responded under multiple fixed-ratio fixed-ratio schedules with equal fixed ratios. One component provided immediate reinforcement and the other provided reinforcement after a delay, signaled by the offset of the key light. The components were presented quasirandomly so that all four possible transitions occurred in each session. The delay was varied over 0, 4, 8, 16, and 32 s with fixed-ratio 5 schedules, and over 0, 8 and 32 s with fixed-ratio 1, 15 and 40 schedules. Main effects of fixed-ratio value and delay duration were detected on between-ratio pauses. Pauses were longer when the multiple-schedule stimulus correlated with a delayed-reinforcer component was presented, with the longest pauses occurring at the transition from a component with an immediate reinforcer to one with a delayed reinforcer. Pause durations were shortest during immediate components. Overall, both the presence or absence of a delay in the upcoming component, and the presence or absence of a delay in the preceding component affected pause length, but the upcoming delay had the larger effect. Thus changes in delay had similar effects to past reports of the effects of changes in response force, response requirement, and reinforcer magnitude in multiple fixed-ratio fixed-ratio schedules.

Food and sounds (white noise, a food call and the sound of other chicks) were used in an attempt to establish conditioned place preferences with domestic hen chicks. Thirty-two chicks were randomly allocated to one of the 4 groups, and exposed to a 3-compartment apparatus to establish a baseline of their movements across 4 15-min sessions. They were then confined to one compartment and provided with free access to food or exposed to one sound for 15 min and then they were confined to the alternate compartment with no food or sound for 15 min. This process was repeated 3 times. Post-conditioning test sessions showed a conditioned place preference towards the area associated with food and away from the area associated with white noise. After conditioning, chicks showed no preference for spending time in the side associated with the food call or the sounds of other chicks; however, they entered a compartment first more often when it was associated with the food call and less often when it was associated with chick-sounds. Overall, these results showed that it was possible to use the conditioned place preference procedure to assess the effects of sounds and that the procedure has potential use for assessing other environmental stimuli., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Many studies, including some dealing with shot selection in basketball and play selection in football, demonstrate that the generalized matching equation provides a good description of the allocation of time and effort to alternative responses as a function of the consequences of those alternatives. We examined whether it did so with respect to left- and right-handed at bats (alternative responses) and left- and right-handed total bases earned, runs batted in, and home runs (three consequences) for the outstanding baseball switch-hitters Mickey Mantle, Eddie Murray, and Pete Rose. With all hitters, undermatching, suggesting insensitivity to the consequences of behavior (reinforcement), was evident and there was substantial bias towards left-handed at bats. These players apparently chose handedness based on the rule "bat opposite the pitcher," not on differential consequences obtained in major league games. The present findings are significant in representing a counter-instance of demonstrations of a matching relationship in sports in particular and in human behavior in general and in calling attention to the need for further study of the variables that affect choice.

Brushtail possums (Trichosurus vulpecula) were trained to press a right lever when a tone was presented (a tone-on trial) and a left lever when a tone was not presented (a tone-off trial) to gain access to food. During training the tone was set at 80 dB(A), with a frequency of 0.88 kH for 3 possums and of 4 kH for the other 2. Once accuracy was over 90% correct across five consecutive sessions, a test session was conducted where the intensity of the tone was reduced by 8 dB(A) over blocks of 20 trials until accuracy over a block fell below 60%. After each test session, training sessions were reintroduced and continued until accuracy was again over 90%, when another test session was conducted. This process continued until there were at least five test sessions at that tone frequency. The same procedure was then used with frequencies of 0.20, 0.88, 2, 4, 10, 12.5, 15, 20, 30, and 35 kHz. Percentage correct and d' decreased approximately linearly for all possums as tone intensity reduced. Both sets of lines were shallowest at the higher frequencies and steepest at the lower frequencies. Hit and false alarm rates mirrored each other at high frequencies but were asymmetric at lower frequencies. Equal d' contours showed that sensitivity increased from 2 to 15 kHz and continued to be high over 20 to 35 kHz. The possums remained sensitive to the 20 to 35 kHz tones even at low intensities. The present study is the first to report the abilities of possum to detect tones over this range of frequencies and its results support the findings of a microelectrode mapping survey of possums' auditory cortex.

In comparing open and closed economies, researchers often arrange shorter sessions under the former condition than under the latter. Several studies indicate that session length per se can affect performance and there are some data that indicate that this variable can influence demand functions. To provide further data, the present study exposed domestic hens to series of increasing fixed-ratio schedules with the length of the open-economy sessions varied over 10, 40, 60, and 120 min. Session time affected the total-session response rates and pause lengths. The shortest session gave the greatest response rates and shortest pauses and the longest gave the lowest response rates and longest pauses. The total-session demand functions also changed with session length: The shortest session gave steeper initial slopes (i.e., the functions were more elastic at small ratios) and smaller rates of change of elasticity than the longest session. Response rates, pauses, and demand functions were, however, similar for equivalent periods of responding taken from within sessions of different overall lengths (e.g., total-session data for 10-min sessions and the data for the first 10 min of 120-min sessions). These findings suggest that differences in session length can confound the results of studies comparing open and closed economies when those economies are arranged in sessions that differ substantially in length, hence data for equivalent-length periods of responding, rather than total-session data, should be of primary interest under these conditions.

The use of television and computer screens for presenting stimuli to animals is increasing as it is non-invasive and can provide precise control over stimuli. Past studies have used cathode ray tube (CRT) screens; however, there is some evidence that these give different results to non-flickering thin film transistor (TFT) screens. Hens' critical flicker fusion frequency ranges between 80 and 90 Hz--above standard CRT screens. Thus, stimuli presented on CRT screens may appear distorted to hens. This study aimed to investigate whether changing the flicker rate of CRT screens altered hens' discrimination. Hens were trained (in a conditional discrimination) to discriminate between two stimuli on a TFT (flickerless) screen, and tested with the stimuli on a CRT screen at four flicker rates (60, 75, 85, and 100 Hz). The hens' accuracy generally decreased as the refresh rate of the CRT screen decreased. These results imply that the change in flicker rate changed the appearance of the stimuli enough to affect the hens' discrimination and stimulus control is disrupted when the stimuli appear to flicker., (Copyright (c) 2010 Elsevier B.V. All rights reserved.)

Objective: To assess the knowledge, compliance and practice among healthcare workers of occupational infection control at two hospitals in Jamaica., Methods: Employing a cross-sectional study design, medical personnel (physicians and nurses) at two hospitals in Jamaica, were studied, utilizing a structured questionnaire consisting of 14 items to collect the data., Results: Participants considered the following fluids, not blood stained, high risk for HIV transmission: breast milk (79%), saliva (14%), urine (27%), pleural fluid (53%), CSF (55%), synovial fluid (37%), faeces (27%), peritoneal fluid (53%) and vomitus (21%). The respondents estimated the risk of transmission of infection after a needlestick injury from a patient with: HIV, mean 22.5%, HB, 34% and HCV, 26%. Needles for drawing blood were identified as having the highest risk for transmission of infections in 63%. The following precautions were adhered to all the time: wearing gloves (38%), not re-sheathing needles (22%), not passing needles directly to others (70%), properly disposing of sharps (86%) and regarding patients' blood and other high risk fluid as potentially infected (62%). Post exposure, 43% indicated bleeding/squeezing the NSI site as the initial first-aid procedure, washing with soap and water (29%) and irrigating the area with water (20%)., Conclusions: Healthcare workers are aware of the risk of transmission of infection, however compliance with universal precautions was inadequate. An improvement in knowledge and practice with clear guidelines are needed and a comprehensive programme to educate HCWs regarding compliance with universal precautions is urgently required.

Objective: To assess the prevalence of needlestick injuries (NSIs) and other high risk exposures among healthcare workers at two hospitals in Jamaica., Methods: Employing a cross-sectional study design, medical personnel (physicians, nurses) at two hospitals in Jamaica, were studied, utilizing a structured questionnaire consisting of 14 items to collect data on needle stick injuries and other injuries., Results: There were 67 needlestick injuries in 47 persons. Of those sustaining an injury, 52% of physicians and 40% of nurses had NSIs. Re-capping needles accounted for 21% of injuries, various minor procedures, 21%, injury during surgery, 19.4% and taking blood, 12%. In those sustaining NSIs, 47% were reported and 26% of reported cases received counselling. Appropriate blood tests were performed on 34% and post-exposure prophylaxis (PEP) for HIV was administered to 30%. Hollow bore needles caused 47.8% of injuries, 25.4% occurred with suture needles and 19.4% with intravenous branulas. Other occupational exposure was reported by 31%, including blood on hands and other body parts 39%, blood to face and eyes, 18%, splashed with liquor, 18%, splashed with bloody fluid, 11% and contact with vomitus and urine in eye, 4%., Conclusion: Needlestick injuries and other high risk exposures were high; incident reporting and post exposure management were inadequate. A comprehensive programme to address factors that contribute to the occurrence of NSIs and other occupational exposures is urgently needed.

Concurrent schedules were used to establish 6 hens' preferences for three foods. The resulting biases suggested wheat was preferred over honey-puffed and puffed wheat, and puffed wheat was the least preferred food. The hens then responded under fixed-ratio schedules for each food in 40-min (excluding reinforcer time) sessions, with the response requirement doubling each session until no reinforcers were received. At the smaller ratios, the less preferred the food, the faster the hens' overall response rates (mainly as a result of shorter postreinforcement pauses) and the more reinforcers they received. The relations between the logarithms of the number of reinforcers obtained (consumption) and the response ratio (price) were well fitted by curvilinear demand functions. Wheat produced the smallest initial consumption (ln L), followed by honey-puffed and puffed wheat, respectively. The response requirement at which the demand functions predicted maximal responding (P(max)) were larger for wheat than for the other foods. Normalizing consumption and price, as suggested by Hursh and Winger (1995), moved the data for the three foods towards a single demand function; however, the P(max) values were generally largest for puffed wheat. The results of normalization, as suggested by Hursh and Silberberg (2008), depended on the k value used. The parameter k is related to the range of the data, and the same k value needs to be used for all data sets that are compared. A k value of 8.0 gave significantly higher essential values (smaller alpha values) for puffed wheat as compared to honey-puffed wheat and wheat, and the P(max) values, in normalized standard price units, were largest for puffed wheat. Normalizing demand by converting the puffed and honey-puffed wheat reinforcers to wheat equivalents (by applying the bias parameter from the concurrent-schedules procedure) maintained separate demand functions for the foods. Those for wheat had the smallest rates of change in elasticity (a) and, in contrast to the other analyses, the largest P(max) values. Normalizing demand in terms of concurrent-schedule preference appears to have some advantages and to merit further investigation.

This paper compared two general methods for assessing critical fusion frequency in hens (gallus gallus domesticus). The first method was a conditional discrimination procedure with the stimuli presented successively. The second was a two-alternative forced-choice procedure with the stimuli presented simultaneously. It was found that both methods of stimulus presentation gave comparable results suggesting that either method is useful when investigating psychophysics in animals. The results also show that hens' critical fusion frequency is considerably higher than that of humans which may account for hens' inability to recognise images presented on standard computer or television monitors.

Background: Individuals donating whole blood 13 times in a 2-year period without development of iron deficiency anemia (superdonors) are a self-selected population that is deferred for low hematocrit (Hct) level less frequently than other donors., Study Design and Methods: Iron metabolism was assessed in 138 superdonors through a questionnaire and measurement of Hct, serum ferritin, serum hepcidin, and serum growth differentiation factor 15 (GDF15). Genetic testing for HFE and JAK-2 mutations was also performed., Results and Conclusions: Iron deficiency (ferritin level, <30 microg/L) is present in more than 60 percent of superdonors. Behaviors altering iron status included casual use of iron supplements in males, but not in females, and cigarette smoking that produced increased Hct associated with decreased ferritin. The striking biochemical characteristic of superdonors is greatly decreased serum hepcidin, consistent with their need to absorb maximal amounts of dietary iron to replace that lost from blood donation. GDF15 is normal in most superdonors, indicating that GDF15 overexpression arising from the expanded erythroid pool necessary to replace donated red cells is not the biochemical mechanism for the decreased serum hepcidin. Mutations in JAK-2 were not found, indicating that undiagnosed polycythemia vera is not a common cause for successful repeated blood donation by superdonors. Mutations in HFE associated with hemochromatosis were present in superdonors at the same frequency as the normal population. However, superdonors heterozygous for the H63D mutation in HFE had significantly decreased hepcidin : ferritin ratios demonstrating for the first time that the heterozygous state for HFE mutations is associated with alterations in hepcidin expression.

The ability of four horses (Equus caballus) to discriminate coloured (three shades of blue, green, red, and yellow) from grey (neutral density) stimuli, produced by back projected lighting filters, was investigated in a two response forced-choice procedure. Pushes of the lever in front of a coloured screen were occasionally reinforced, pushes of the lever in front of a grey screen were never reinforced. Each colour shade was randomly paired with a grey that was brighter, one that was dimmer, and one that approximately matched the colour in terms of brightness. Each horse experienced the colours in a different order, a new colour was started after 85% correct responses over five consecutive sessions or if accuracy showed no trend over sessions. All horses reached the 85% correct with blue versus grey, three horses did so with both yellow and green versus grey. All were above chance with red versus grey but none reached criterion. Further analysis showed the wavelengths of the green stimuli used overlapped with the yellow. The results are consistent with histological and behavioural studies that suggest that horses are dichromatic. They differ from some earlier data in that they indicate horses can discriminate yellow and blue, but that they may have deficiencies in discriminating red and green.

Background and Aims: In kiwifruit (Actinidia), the number of nodes per shoot is highly variable and is influenced by genotype and environmental conditions. To understand this developmental plasticity, three key processes were studied: organogenesis by the shoot apical meristem during shoot growth; expansion of phytomers; and shoot tip abortion., Methods: Studies were made of organogenesis and shoot tip abortion using light and scanning electron microscopy. The effect of temperature on shoot growth cessation was investigated using temperature indices over the budbreak period, and patterns of shoot tip abortion were quantified using stochastic modelling., Key Results: All growing buds began organogenesis before budbreak. During shoot development, the number of phytomers initiated by the shoot apical meristem is correlated with the number of expanding phytomers and the mean internode length. Shoot tip abortion is preceded by growth cessation and is not brought about by the death of the shoot apical meristem, but occurs by tissue necrosis in the sub-apical zone. For most genotypes studied, the probability of shoot tip abortion is higher during expansion of the preformed part of the shoot. Lower temperatures during early growth result in a higher probability of shoot tip abortion., Conclusions: Organogenesis and shoot tip abortion are controlled independently. All buds have the potential to become long shoots. Conditions that increase early growth rate postpone shoot tip abortion.

To examine the effects on concurrent performance of independent manipulations of response-unit duration and number, 6 hens were exposed to concurrent second-order schedules of reinforcement. Each first-order operant unit required completion of a fixed-ratio schedule within the time specified by a fixed-interval schedule, with one further response completing the fixed-interval schedule. The fixed-ratio and fixed-interval requirements comprising the first-order operant units were systematically and independently varied under three pairs of concurrent variable-interval schedules to produce differences in the first-order response and duration requirements (response and duration differentials). These manipulations produced consistent changes in response, time, and operant-unit biases. A 1:4 response differential biased the time and operant-unit measures towards the smaller fixed ratio, but to a degree less than the imposed response differential. The response-based biases favored the larger fixed ratio. Duration differentials of 4:1 and 8:1 biased the response and operant-unit measures towards the shorter fixed interval, again less than the imposed duration differential, but the time biases remained close to zero. Both sorts of differentials acted to bias operant-unit completions more systematically than the other measures, but undermatching to the differentials occurred. The undermatching appears to have arisen from a pattern of fix and sample (in which visits to the less preferred alternative involved only a single completed operant unit) under combinations of unequal operant-unit requirements and reinforcer rates. The response and time bias measures appeared to arise as by-products of the changes in operant-unit completions.

The common brushtail possum (Trichosurus vulpecula) is a readily accessible marsupial that has been shown to adapt relatively well to captivity. The aim of this paper is to outline the husbandry procedures, experimental equipment, and methodologies used successfully within our possum colony since 1995.