Animal-assisted Social Skills Training for Children with Autism Spectrum Disorders

Recent research indicates that youth with autism spectrum disorder (ASD) show increases in prosocial behaviors in the presence of animals, yet few studies have examined the effects of incorporating animals into treatments. The current study evaluated the effectiveness of an animal-assisted social skills training group for youth with ASD. It was hypothesized that incorporating dogs into social skills training (SST) would produce a greater effect on improving social skills, theory of mind, and feelings of inclusion than would be obtained from SST without an animal present. We compared social skills groups with therapy dogs to traditional social skills groups without an animal present. Students with ASD attending school at a therapeutic treatment facility (n = 31; ages 8–14) were assigned to either experimental or control groups, which were both provided with 12 weeks of weekly treatment. Following participation in SST, participants in the groups with dogs were rated as significantly less symptomatic than participants in the traditional social skills group on the Social Responsiveness Scale (SRS-2), a teacher-rated measure of autism-related symptoms. Based on self-report ratings using the Children’s Depression Inventory (CDI-2), participants in the groups with dogs experienced significantly greater reductions in symptoms measured by the Interpersonal Problems and Functional Problems subscales, and not on the other subscales of the CDI-2. Both groups showed improvement in theory of mind and decreased feelings of isolation and overall depressive symptoms; however, the effect of group on change over time was not significant. On the Social Language Development Test (SLDT), no significant differences were observed. The current findings indicate animal-assisted social skills training may be more beneficial for improving social skills and reducing related affective symptoms than traditional training models.     

Factors Affecting the Human Interpretation of Dog Behavior

Several factors influence how we interpret the behavior of another individual. In the current study, we investigated the effect of level of animal empathy, as well as the level of experience with dogs, on the interpretation of dog behavior. Forty-seven veterinary students participated in the study. Each student filled out a printed questionnaire on their experiences and skills with dogs, and then completed the Animal Empathy Scale. They were shown five 2-minute videos of dogs, and asked to cross off 19 visual analogue scales after each video clip, assessing 19 adjectives for each of the dogs. Principal component analysis (PCA) was performed on all of the visual analogue scale scores for each of the five videos. For every PCA, one of the components retained related to aggressiveness. For students with no prior responsibility for a dog, animal empathy score showed significant inverse correlations with the aggressiveness-component for four of the five videos watched by the students (r = –0.38, p = 0.044; r = –0.39, p = 0.039; r = –0.38, p = 0.047; r = –0.51, p = 0.005). Animal empathy did not show any significant correlation with components related to other types of emotion or behavior. There was no effect of any of the self-reported skills with dogs on the interpretation of dog behavior, and having had a dog in the family as a child only had sporadic effects. These results indicate that people with a low level of animal empathy and no prior responsibility for a dog assess dog behavior and emotion related to aggressiveness as more pronounced than people with a high level of animal empathy. The results also point to possible interactions between animal empathy, experience with dogs, and interpretation of dog behavior.     

Low sodium intake does not impair renal compensation of hypoxia-induced respiratory alkalosis.

Acute hypoxia causes hyperventilation and respiratory alkalosis, often combined with increased diuresis and sodium, potassium, and bicarbonate excretion. With a low sodium intake, the excretion of the anion bicarbonate may be limited by the lower excretion rate of the cation sodium through activated sodium-retaining mechanisms. This study investigates whether the short-term renal compensation of hypoxia-induced respiratory alkalosis is impaired by a low sodium intake. Nine conscious, tracheotomized dogs were studied twice either on a low-sodium (LS = 0.5 mmol sodium x kg body wt-1 x day-1) or high-sodium (HS = 7.5 mmol sodium x kg body wt-1 x day-1) diet. The dogs breathed spontaneously via a ventilator circuit during the experiments: first hour, normoxia (inspiratory oxygen fraction = 0.21); second to fourth hour, hypoxia (inspiratory oxygen fraction = 0.1). During hypoxia (arterial PO2 34.4 +/- 2.1 Torr), plasma pH increased from 7.37 +/- 0.01 to 7.48 +/- 0.01 (P < 0.05) because of hyperventilation (arterial PCO2 25.6 +/- 2.4 Torr). Urinary pH and urinary bicarbonate excretion increased irrespective of the sodium intake. Sodium excretion increased more during HS than during LS, whereas the increase in potassium excretion was comparable in both groups. Thus the quick onset of bicarbonate excretion within the first hour of hypoxia-induced respiratory alkalosis was not impaired by a low sodium intake. The increased sodium excretion during hypoxia seems to be combined with a decrease in plasma aldosterone and angiotensin II in LS as well as in HS dogs. Other factors, e.g., increased mean arterial blood pressure, minute ventilation, and renal blood flow, may have contributed.     

Hounds and Homesickness: The Effects of an Animal-assisted Therapeutic Intervention for First-Year University Students

Transitioning from high school to university can prove to be a for midable challenge for many first-year students, with many experiencing home sickness. Given that students who experience homesickness are more likely than their non-homesick cohorts to drop out of university, universities have a vested interest in supporting students during their first-year transition. Programs that provide opportunities for human–animal interactions on campus are gaining popularity as one way of increasing students’ wellbeing. The current study examined the effects of an 8-week animal-assisted therapy (AAT) program on first-year university students’ wellbeing. An initial feasibility study (n = 86) was conducted that provided opportunities for students to interact, in small groups, with trained therapy dogs and their volunteer handlers. Results indicated that this program reduced participants’ levels of homesickness and increased their satisfaction with life. An experimental study was then conducted utilizing a similar 8-week group AAT program. Participants (n = 44) were assigned to either a treatment condition (i.e., the AAT program) or to a no-treatment condition (akin to a wait-list control). At the end of the eight weeks, participants in the AAT program reported greater reductions in homesickness and greater increases in satisfaction with life than did those in the no-treatment condition. From beginning to end of the program, participants in the treatment group evidenced reductions in homesickness and increases in satisfaction with life and connectedness to campus, while participants in the no-treatment condition evidenced an increase in homesickness and no changes in satisfaction with life and connectedness to campus. Results of both the feasibility study and the experimental study support the use of AAT programs to increase the wellbeing of first-year university students experiencing homesickness.     

The effects of group and individual animal-assisted therapy on loneliness in residents of long-term care facilities

Abstract

Animal-assisted therapy (AAT) has been shown to reduce the loneliness of residents in long-term care facilities (LTCFs). In this study, we determined the relative contribution of socialization (human–human bonding) and human–animal bonding as mechanisms by which AAT reduces loneliness. Residents in LTCFs volunteering for AAT were randomized to receive AAT as individuals (Individual) or in groups of two to four (Group). Individual AAT was used as a measure of animal–human bonding, and Group AAT was used as a measure of the combination of animal–human bonding and socialization. Any greater effect of Group AAT in comparison to Individual AAT would be ascribed to socialization. Thirty-seven residents of LTCFs, who were cognitively intact, volunteered for AAT, and scored as significantly lonely on the UCLA Loneliness Scale (Version 3), were studied. Six weeks of AAT, one 30-minute session per week, in an individual or group setting was performed, with posttesting during week five. Two residents dropped out of each group, giving us group sizes of 17 (Individual) and 16 (Group). A two-way ANOVA showed a statistically significant effect of pretest vs. posttest scores (F_(1,31) = 25.3, p < 0.001), with no effect of Group vs. Individual or of interaction. Newman Keuls post-hoc tests showed that the pretest scores for Individual and Group participants did not differ. There was a significant difference between pretest and posttest scores for Individual participants (p < 0.05) but not for Group participants. There was no difference between the posttest values for Individual vs. Group. When the data from all 33 participants were combined, Delta scores (pretest minus posttest), correlated positively (p < 0.01) with pretest scores, showing that lonelier individuals benefited more from AAT. In conclusion, AAT was more effective in improving loneliness in residents of LTCFs when given individually than in a group situation. Therefore, the main effect of AAT was not mediated by socialization.     

Disentangling psychobiological mechanisms underlying internalizing and externalizing behaviors in youth: longitudinal and concurrent associations with cortisol

Research examining cortisol dysregulation is seemingly contradictory with studies showing that both internalizing and externalizing behaviors are related to high and low cortisol. One extant theory to explain divergent findings in the stress literature is that both hypo- and hyper-arousal of the hypothalamic-pituitary-adrenal (HPA) axis may be present depending on time since onset of the stressor. This theory may extend to the onset of internalizing and externalizing behaviors. Data from 96 youth participating in a longitudinal project were used to examine this possibility. Composite measures of internalizing and externalizing behaviors at both childhood and early adolescence were formed using mother and teacher reports. Multiple salivary cortisol samples were also collected over two consecutive days during early adolescence. Problematic behaviors were associated with cortisol and the direction of the association was dependent on amount of time passed since onset of the behaviors. When examined concurrently in adolescence, youth with more internalizing behaviors had higher morning cortisol; however, when examined longitudinally, youth with more internalizing behaviors in childhood had lower morning cortisol levels as adolescents. Youth with more externalizing behaviors in childhood had flattened diurnal cortisol rhythms as adolescents, and this finding persisted when examined in adolescence. Cortisol dysregulation was greatest in children with the most severe behavior problems. Findings support the theoretical model of blunting of the HPA axis over time. While the HPA axis may show hyper-arousal when youth first display behaviors, long-term exposure may lead to a hypo-arousal of the HPA axis which culminates in a dysregulated diurnal rhythm.     

Companion Animals and Loneliness: A Systematic Review of Quantitative Studies

ABSTRACT

The aim of this systematic review was to evaluate quantitative studies of companion animals and human loneliness. Five electronic databases (PubMed, Medline, Web of Science, Academic Search Premier, Psychlnfo) were searched for articles on companion animals (including animal-assisted therapies [AAT]) and human loneliness. Searches were not limited to a particular language or timeframe. Three randomized controlled studies (RCTs), one controlled study, one prospective cohort study, two longitudinal, and 14 cross-sectional studies satisfied all inclusion criteria and were each evaluated independently by both authors according to standardized criteria, with disagreements resolved by discussion. All except one study was underpowered. The methodological quality of the three RCTs was low, as measured on the Jadad scale. Eleven studies reported positive findings, of which five related to service dogs. While none of the positive studies provided convincing evidence that companion animals help to alleviate loneliness, there was promising evidence that AAT may do this (although effects may be due to aspects of the therapy rather than the animal). As further cross-sectional studies are unlikely to improve understanding of the role of companion animals on human loneliness, we suggest that there is a need for rigorous and adequately powered RCTs.     

Comparative efficacy on dogs of a single topical treatment with fipronil/(S)-methoprene or weekly physiological hygiene shampoos against Ctenocephalides felis in a simulated flea-infested environment

Flea infestations of pets continue to persist due to the lack of knowledge of flea biology and ecology. It is not unusual that pet owners believe regular hygiene, such as shampooing their dogs can replace regular insecticidal treatment. The objective of this study was to compare in a flea simulated environment, modelling exposure similar to that found in a home, that the use of regular physiological shampoo does not control fleas adequately when compared to a long acting topical formulation. Three groups of six dogs were formed: one untreated control group, one group treated monthly with the topical formulation of fipronil/(S)-methoprene, and a third group treated weekly with a hygiene shampoo. All dogs were infested with adult unfed Ctenocephalides felis fleas (200±5) on Days -28 and -21. Each animal's sleeping box was fitted with a plastic cup mounted to the inside roof of the box. The sleeping bench of each animal was covered with a carpet to accommodate flea development. The dogs were maintained in their kennels throughout the study. In order to maintain the environmental flea challenge, C. felis pupae (100±5) were placed in the plastic cup in each animal's sleeping box on Days -14, -7, 0, 7, 14, 21, 28, 35 and 42. The dogs were combed and fleas counted weekly on Days -1, 3, 10, 17, 24, 31, 38, 45, and 51. The fleas were placed immediately back on the dogs. On Day 60, fleas were counted and removed. Flea infestations in the untreated control group at each count averaged between 46.2 and 74.2 fleas throughout the study. The average number of fleas infesting dogs was significantly different (p<0.05) between the untreated and the two treatment groups and between the two treatment groups at all counts throughout the two months study (Days 3, 10, 17, 24, 31, 38, 45, 51 and 60). The efficacy was never below 99.1% in the fipronil/(S)-methoprene group, and efficacy in the shampoo group was never above 79.2%. Weekly shampooing in treatment group 3 was intentionally delayed after Day 42, to evaluate wether missing a weekly bath would affect the flea population. The Day 48 data indicate that forgetting or delaying a single weekly shampooing resulted in a clear increase in flea numbers and a significant decrease in efficacy from 68.2% to 34.8%. The fipronil(S)/methoprene treatment allowed a continuous control as demonstrated by the high efficacy against fleas, and also the number of flea-free dogs on seven of the nine weekly assessments, in spite of what was essentially a continuous flea challenge model.     

The Relationship between Empathy,Perception of Pain and Attitudes toward Pets among Norwegian Dog Owners

ABSTRACT

Anthropomorphism, attachment level, and belief in animal mind, as well as owners' level of empathy and attitudes toward their pets, are some of the factors that affect human–animal interactions. Owners' ability to identify painful conditions in their pets may have important consequences for the welfare of these animals. In addition to characterizing the typical Norwegian dog owner, the aim of this work was to study the relationship between empathy, attitudes, and perceived animal pain. A sample of 3,413 dog owners in Norway received an internet-based questionnaire (QuestBack?), to which1896 responded. The questionnaire included four parts: demographics, the Pet Attitude Scale (PAS), the Animal Empathy Scale (AES), and the Pain Assessment Instrument (PAI). For the PAI, participants were presented with 17 photos, showing dogs experiencing painful situations of varying degrees, and were asked to rate the level of pain they believed each animal was enduring, using a Visual Analogue Scale (VAS). Results showed that Norwegian dog owners had very high levels of animal-directed empathy and equally high levels of positive attitudes toward pets. There were differences based on gender, childhood pet keeping, income and education. Differences were also found rooted in owners' use of their dog, whether kept for companionship or hunting, as well as household size, an indication of human social relations. A strong, positive correlation (r = 0.58) was found between animal-directed empathy and positive attitudes toward pets. Empathy was found to be the best predictor of how people rated pain in dogs. The correlations were, however, moderate, indicating that other processes are also involved when observing animals in pain.     

Rapid purification and thermostability of the cytoplasmic aspartate aminotransferase from carrot suspension cultures

Several isoenzymic forms of aspartate aminotransferase (AAT) have been identified in protein extracts from carrot (Daucus carota) cell suspension cultures. The cellular location of the major form (form I) of AAT in carrot suspension cultures was determined by heat inactivation, subcellular fractionation, and amino acid sequence analysis. In mammalian systems, there are two forms of AAT, a heat-stable cytoplasmic form and a heat-labile form in the mitochondria. The thermostability of three isoenzymes of carrot AAT was examined, and the results showed that form I was more thermostable than forms II or III. Organelles were separated in sucrose gradients by isopynic centrifugation. Activity for form I was identified in the soluble fractions and not in fractions containing peroxisomes, proplastids, or mitochondria. Form I was purified to homogeneity and endoproteolytically cleaved, and the peptide fragments were separated by reverse phase chromatography. Analysis of the sequence data from two of the polypeptides showed that the amino acid identity of form I is more conserved to the animal cytoplasmic AAT than to animal mitochondrial AAT sequences. These data strongly suggest that form I of AAT from carrot is the cytoplasmic isoenzyme. Additionally, a rapid purification scheme for form I of AAT from carrot is presented using selective heat denaturation and anion-exchange chromatography.     

Expanding the Clinical Indications for α1-Antitrypsin Therapy

α₁-Antitrypsin (AAT) is a 52-kDa circulating serine protease inhibitor. Production of AAT by the liver maintains 0.9–1.75 mg/mL circulating levels. During acute-phase responses, circulating AAT levels increase more than fourfold. In individuals with one of several inherited mutations in AAT, low circulating levels increase the risk for lung, liver and pancreatic destructive diseases, particularly emphysema. These individuals are treated with lifelong weekly infusions of human plasma–derived AAT. An increasing amount of evidence appears to suggest that AAT possesses not only the ability to inhibit serine proteases, such as elastase and proteinase-3 (PR-3), but also to exert antiinflammatory and tissue-protective effects independent of protease inhibition. AAT modifies dendritic cell maturation and promotes T regulatory cell differentiation, induces interleukin (IL)-1 receptor antagonist and IL-10 release, protects various cell types from cell death, inhibits caspases-1 and -3 activity and inhibits IL-1 production and activity. Importantly, unlike classic immunosuppressants, AAT allows undeterred isolated T-lymphocyte responses. On the basis of preclinical and clinical studies, AAT therapy for nondeficient individuals may interfere with disease progression in type 1 and type 2 diabetes, acute myocardial infarction, rheumatoid arthritis, inflammatory bowel disease, cystic fibrosis, transplant rejection, graft versus host disease and multiple sclerosis. AAT also appears to be antibacterial and an inhibitor of viral infections, such as influenza and human immunodeficiency virus (HIV), and is currently evaluated in clinical trials for type 1 diabetes, cystic fibrosis and graft versus host disease. Thus, AAT therapy appears to have advanced from replacement therapy, to a safe and potential treatment for a broad spectrum of inflammatory and immune-mediated diseases.     

Empathy and Belief in the Mental Experience of Animals

ABSTRACT

Aspects of empathy are examined, including the relationship between empathy and perceived similarity or identification. Cognitive judgments of similarity appear to predispose us to the experience of empathy. An important aspect of similarity where animals are concerned is their perceived mental endowment (Fenton & Hills 1988). Therefore, a positive relationship was hypothesized between empathy for animals and “belief in animal mind” (i.e., beliefs about the extent to which animals have awareness, thoughts, and feelings). In a sample comprising three groups (animal rights supporters, farmers, and urban public) the expected relationship was found, r(153) = .47, p < .001; however, it was not consistent across the subject groups. Analysis suggested that the relationship between perceived similarity and empathy is mediated by conflicting instrumental motivations. Implications of the results for humane and environmental education are discussed.     

Expanding the Clinical Indications for α(1)-Antitrypsin Therapy

α(1)-Antitrypsin (AAT) is a 52-kDa circulating serine protease inhibitor. Production of AAT by the liver maintains 0.9-1.75 mg/mL circulating levels. During acute-phase responses, circulating AAT levels increase more than fourfold. In individuals with one of several inherited mutations in AAT, low circulating levels increase the risk for lung, liver and pancreatic destructive diseases, particularly emphysema. These individuals are treated with lifelong weekly infusions of human plasma-derived AAT. An increasing amount of evidence appears to suggest that AAT possesses not only the ability to inhibit serine proteases, such as elastase and proteinase-3 (PR-3), but also to exert antiinflammatory and tissue-protective effects independent of protease inhibition. AAT modifies dendritic cell maturation and promotes T regulatory cell differentiation, induces interleukin (IL)-1 receptor antagonist and IL-10 release, protects various cell types from cell death, inhibits caspases-1 and -3 activity and inhibits IL-1 production and activity. Importantly, unlike classic immunosuppressants, AAT allows undeterred isolated T-lymphocyte responses. On the basis of preclinical and clinical studies, AAT therapy for nondeficient individuals may interfere with disease progression in type 1 and type 2 diabetes, acute myocardial infarction, rheumatoid arthritis, inflammatory bowel disease, cystic fibrosis, transplant rejection, graft versus host disease and multiple sclerosis. AAT also appears to be antibacterial and an inhibitor of viral infections, such as influenza and human immunodeficiency virus (HIV), and is currently evaluated in clinical trials for type 1 diabetes, cystic fibrosis and graft versus host disease. Thus, AAT therapy appears to have advanced from replacement therapy, to a safe and potential treatment for a broad spectrum of inflammatory and immune-mediated diseases.     

Social Modulation of Contagious Yawning in Wolves

On the basis of observational and experimental evidence, several authors have proposed that contagious yawn is linked to our capacity for empathy, thus presenting a powerful tool to explore the root of empathy in animal evolution. The evidence for the occurrence of contagious yawning and its link to empathy, however, is meagre outside primates and only recently domestic dogs have demonstrated this ability when exposed to human yawns. Since dogs are unusually skilful at reading human communicative behaviors, it is unclear whether this phenomenon is deeply rooted in the evolutionary history of mammals or evolved de novo in dogs as a result of domestication. Here we show that wolves are capable of yawn contagion, suggesting that such ability is a common ancestral trait shared by other mammalian taxa. Furthermore, the strength of the social bond between the model and the subject positively affected the frequency of contagious yawning, suggesting that in wolves the susceptibility of yawn contagion correlates with the level of emotional proximity. Moreover, female wolves showed a shorter reaction time than males when observing yawns of close associates, suggesting that females are more responsive to their social stimuli. These results are consistent with the claim that the mechanism underlying contagious yawning relates to the capacity for empathy and suggests that basic building blocks of empathy might be present in a wide range of species.     

The Protective Association between Pet Ownership and Depression among Street-involved Youth: A Cross-sectional Study

Street-involved youth represent a particularly vulnerable subsection of the homeless population and are at increased risk of health problems, substance abuse, and depression. Qualitative research has demon- strated that animal companions help homeless youth cope with loneliness, are motivators for positive change, such as decreasing drug or alcohol use, provide unconditional love without judgement, and improve youths’ sense of health. To quantitatively investigate the association between depression and pet ownership among street-involved youth, a cross-sectional study was per- formed with a convenience sample of 189 street-involved youths who were surveyed in four cities in Ontario, Canada, 89 of whom were pet owners and 100 of whom were not. Logistic regression modelling found pet ownership to be negatively associated with depression in the study population (controlling for gender, regular use of drugs, and time since youth left home), with the odds of being depressed three times greater for youths who did not own pets. While pet ownership among street-involved youth has many liabilities, includ- ing impairing youths’ ability to access shelter, services, and housing and employment opportunities, companion animals may offer both physical and psychosocial benefits that youth have difficult attaining. This finding highlights the importance of increased awareness among youth service providers of the potential impacts of pet ownership for street-involved youth.     

Role of 4-H Dog Programs in Life Skills Development

Stress management, resilience, learning-to-learn, self-esteem, and empathy are life skills that play a pivotal role in the psychosocial development of youth who are prepared to manage everyday challenges, and are caring toward people and animals. We hypothesized that 4-H dog club membership is associated with improved life skills of youth participating in these activities compared with youth who do not. We surveyed Washington and Idaho youth (n = 150, 6–17 years old, M = 11.5) in three conditions: 4-H clubs conducting dog-focused activities (4-H dog clubs), 4-H clubs conducting activities not involving dogs (4-H non-dog clubs), and school youth not involved in 4-H (school group). Life skills, and attitude toward and attachment to pets, were assessed using the Emotional Quotient Inventory: Youth Version (Short), Self-Perception Profile for Children, Social Skills Improvement System Rating Scales, Pet Attitude Scale, and Lexington Attachment to Pets Scale. Analysis of covariance was used to evaluate main effects of condition and covariates (age, sex, number of siblings, and dog(s) at home), and two-way interaction effects on questionnaire scores. Condition affected scores: youth in 4-H dog clubs had higher stress management scores (p < 0.01) compared with those in 4-H non-dog clubs and school group conditions, and higher scholastic competence (p < 0.05) and global self-worth (p < 0.01) scores compared with those in the school group. Much of the variation in scores remains unexplained by the predictors investigated. Thus, the extent to which the results represent an interest in 4-H dog activities due to pre-existing characteristics as opposed to changes resulting from the 4-H experience is unclear. Nevertheless, 83% of study participants had at least one dog, and condition effects were detected after accounting for dogs at home, suggesting that 4-H activities involving dogs had beneficial effects over and above any benefits resulting from dog contact per se.     

Young Muslim Immigrants in Norway: An Epidemiological Study of Their Psychosocial Adaptation and Internalizing Problems

The first aim of the present study was to examine internalizing problems and their psychosocial correlates among young Muslim immigrants in Norway as compared to other immigrant youth and host peers. The second aim was to examine adaptation differences among Muslim youth based on national origin and gender. Questionnaire data were collected during school classes from 6306 10th grade students in junior high schools in Oslo. Of the 1666 immigrants in the sample, 1060 (63.3%) originated in countries with majority Muslim population. Internalizing problems were measured in terms of depression and anxiety symptoms. Psychosocial adaptation included measures of general and acculturation-specific risks and resources. In general, Muslims youth appeared well-adapted. However, there were between group differences based on national origin and gender. Also, self-efficacy was identified as an important moderator between acculturation-specific risks and resources and mental health among boys.     

Effects of a 4-week youth baseball conditioning program on throwing velocity

Effects of a 4-week youth baseball conditioning program on throwing velocity. This study examined the effects of a 4-week youth baseball conditioning program on maximum throwing velocity. Thirty-four youth baseball players (11-15 years of age) were randomly and equally divided into control and training groups. The training group performed 3 sessions (each 75 minutes) weekly for 4 weeks, which comprised a sport specific warm-up, resistance training with elastic tubing, a throwing program, and stretching. Throwing velocity was assessed initially and at the end of the 4-week conditioning program for both control and training groups. The level of significance used was p < 0.05. After the 4-week conditioning program, throwing velocity increased significantly (from 25.1 ± 2.8 to 26.1 ± 2.8 m·s) in the training group but did not significantly increase in the control group (from 24.2 ± 3.6 to 24.0 ± 3.9 m·s). These results demonstrate that the short-term 4-week baseball conditioning program was effective in increasing throwing velocity in youth baseball players. Increased throwing velocity may be helpful for pitchers (less time for hitters to swing) and position players (decreased time for a runner to advance to the next base).     

Female but not male dogs respond to a size constancy violation

Differences between sexes in cognitive processes are widespread in humans and permeate many, if not most, cognitive domains. In animal cognition research, however, possible sex differences are still often neglected. Here, we provide striking evidence for a sex-specific response in an object permanence task in domestic dogs (Canis familiaris). Female dogs responded with significantly increased looking times to a violation of expectancy--a ball 'magically' changing size while temporarily occluded. By contrast, male dogs, irrespective of their neuter status, did not respond to the size constancy violation. These results indicate that sex differences in basic cognitive processes may extend to mammals in general, and call for increased consideration of possible sex effects when analysing and interpreting data in animal cognition.     

Genomic structure,expression and evolution of the alfalfa aspartate aminotransferase genes

Genomic clones encoding two isozymes of aspartate aminotransferase (AAT) were isolated from an alfalfa genomic library and their DNA sequences were determined. The AAT1 gene contains 12 exons that encode a cytosolic protein expressed at similar levels in roots, stems and nodules. In nodules, the amount of AAT1 mRNA was similar at all stages of development, and was slightly reduced in nodules incapable of fixing nitrogen. The AAT1 mRNA is polyadenylated at multiple sites differing by more than 250 bp. The AAT2 gene contains 11 exons, with 5 introns located in positions identical to those found in animal AAT genes, and encodes a plastid-localized isozyme. The AAT2 mRNA is polyadenylated at a very limited range of sites. The transit peptide of AAT2 is encoded by the first two and part of the third exon. AAT2 mRNA is much more abundant in nodules than in other organs, and increases dramatically during the course of nodule development. Unlike AAT1, expression of AAT2 is significantly reduced in nodules incapable of fixing nitrogen. Phylogenetic analysis of deduced AAT proteins revealed 4 separate but related groups of AAT proteins; the animal cytosolic AATs, the plant cytosolic AATs, the plant plastid AATs, and the mitochondrial AATs.