bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recombination diversifies chloroplast trnF pseudogenes in Arabidopsis lyrata
Authors: ANSELL S. W. , SCHNEIDER H. , PEDERSEN N. , GRUNDMANN M. , RUSSELL S. J. , VOGEL J. C. 
Published: August 2007

AbstractExtensive intraspecific variation in the chloroplast trnL(UAA)–trnF(GAA) spacer of model plant Arabidopsis lyrata is caused by multiple copies of a tandemly repeated trnF pseudogene undergoing parallel independent changes in copy number. Linkage disequilibrium and secondary structure analyses indicate that the diversification of pseudogene copies is driven by complex processes of structurally mediated illegitimate recombination. Disperse repeats sharing similar secondary structures interact, facilitating reciprocal exchange of structural motifs between copies via intramolecular and intermolecular recombinations, forming chimeric sequences and iterative expansion and contraction in pseudogene copy numbers. Widely held assumptions that chloroplast sequence evolution is simple and structural changes are informative are violated. Our findings have important implications for the use of this highly variable region in Brassicaceae studies. The reticulate evolution and nonindependent nucleotide substitution render the pseudogene inappropriate for standard phylogenetic reconstruction, but over short evolutionary timescales they may be useful for assessing gene flow, hybridization and introgression.
Gene Expression of Secretory Carbonic Anhydrase Isozymes in Striated Ducts of Canine Salivary Glands Using Laser Microdissection System
Authors: Ichihara N. , Tsukamoto A. , Kasuya T. , Shibata S. , Nishita T. , Murakami M. , Amasaki H. , Asari M. 
Published: August 2007

SummaryTo clarify whether striated duct cells in canine salivary glands synthesize secretory carbonic anhydrase (CA‐VI), as is the case with serous acinar cells, the present study utilized laser microdissection to harvest striated duct cells from canine parotid and submandibular glands, and total RNA extracted from these cells was then amplified by reverse transcription‐polymerase chain reaction to assess CA‐VI gene expression. The results confirmed the local expression of CA‐VI mRNA in striated duct cells. This clarified that, in canine salivary glands, CA‐VI is synthesized in not only serous acinar cells, but also striated duct cells.
The Distribution of Taste Buds in Garra rufa
Authors: ÇInar K. , ŞEnol N. , Kuru N. 
Published: August 2007

AbstractThe distribution and relative frequency of external taste buds (TB) of Garra rufa were studied. TB of Garra rufa were observed on different body location (lips, lateral and ventral areas, forehead, operculum and dorsal–pelvic–pectoral–anal fins). TB are at the highest frequency in lips, forehead, pectoral and anal fins. These structures are moderate as a number in operculum, La2 (between pelvic and anal fins) areas, and then decreased a few in other areas.
Intended Receivers and Functional Significance of Grunt and Girney Vocalizations in Free‐Ranging Female Rhesus Macaques
Authors: Whitham Jessica C. , Gerald Melissa S. , Maestripieri Dario 
Published: August 2007

AbstractWe investigated the intended receivers and contexts of occurrence of grunt and girney vocalizations in rhesus macaques (Macaca mulatta) to assess whether these calls are best interpreted as signals of benign intent or as calls that may function to attract the attention of other individuals or induce arousal. We focally observed 19 free‐ranging adult female rhesus macaques. Female calls increased dramatically after infants were born, and most were directed toward mother–infant dyads. When infants were physically separated from their mothers, callers visually oriented toward infants in over 90% of the cases, suggesting that infants were the intended receivers of grunts and girneys. Approaches followed by vocalizations were more likely to lead to the caller grooming the mother, less likely to elicit a submissive response, and more likely to result in infant handling than approaches without calls. Infant handling, however, was not necessarily benign. Vocalizations were often emitted from a distance >1 m and were rarely followed by approaches or social interactions. Our results suggest that grunts and girneys are unlikely to have evolved as signals that encode information about the caller's intention or subsequent behavior. Whereas girneys may be acoustically designed to attract infants’ attention and elicit arousal, grunts may have no adaptive communicative function. Mothers, however, may have learned that other females’ grunts and girneys are unlikely to be associated with significant risk and, therefore, are generally tolerant of the caller's proximity and behavior.
Parental Effort in Relation to Structural Plumage Coloration in the Mountain Bluebird (Sialia currucoides)
Authors: Balenger Susan L. , Scott Johnson L. , Brubaker Jessica L. , Ostlind Emilene 
Published: August 2007

AbstractIndicator models of sexual selection suggest that costly ornaments signal reliable information regarding an individual's quality to potential mates. In species that produce altricial offspring, the amount of parental care provided by both males and females can impact reproductive success. The Good Parent Hypothesis proposes that ornamentation in biparental species can act as an honest signal of parental ability to potential mates. We tested this hypothesis using the mountain bluebird (Sialia currucoides), a sexually dichromatic, socially monogamous species in which both sexes have structurally based ornamental plumage coloration. A male's plumage color predicted neither the rate at which it provisioned nestlings nor brood growth rate. The same was true for females. We also found no indication of assortative mating by color or body condition. Feeding rates within pairs were positively correlated, which we suggest may be due to pairs responding similarly to the perceived needs of nestlings or to local area prey availability. In sum, our results do not support the Good Parent Hypothesis as an explanation for the evolution of ornamental plumage color in mountain bluebirds. We suggest alternative hypotheses for the evolution of ornamental plumage color in this species.
Social Monitoring Reflects Dominance Relationships in a Small Captive Group of Brown Capuchin Monkeys (Cebus apella)
Authors: Pannozzo Pamela L. , Phillips Kimberley A. , Haas Meghan E. , Mintz Eric M. 
Published: August 2007

AbstractIn several studies of social monitoring in primates, subordinate animals directed more visual attention toward dominant animals than vice versa. This behavior is thought to enable subordinate animals to avoid conflict. We sought to clarify whether visual attention behavior functions in this manner in a small captive group of brown capuchin monkeys, Cebus apella. We tested the hypothesis that social monitoring is related to dominance status. Dominance status was determined based on the directionality of aggressive behavior, and visual attention was quantified by using focal animal sampling. Subordinate animals directed significantly more visual attention toward others than dominant animals. Subordinate animals also looked more frequently at the animals that attacked them and others the most. The results indicate that social monitoring behavior in this captive group was driven by conflict‐avoidance.
Male and Female Mate‐Choice Decisions byEvarcha culicivora, An East African Jumping Spider
Authors: Cross Fiona R. , Jackson Robert R. , Pollard Simon D. 
Published: August 2007

AbstractThere has been a considerable recent interest in the criteria by which animals choose mates and in the extent to which mating systems tend to be based on mutual mate choice. In this study, we considerEvarcha culicivora, a salticid spider from East Africa. This species has some unusual characteristics, including active display by females as well as males, males that kill females more frequently than females kill males and wide intrasexual variation in body size. For females, larger males are especially dangerous. Here, we demonstrate, using two experimental designs (live‐mate choice and mount choice), that virgin males, virgin females and previously mated males prefer larger opposite‐sex individuals as potential mates, but mated females prefer smaller, safer males as potential mates.
Geographic Variation in Male Sexual Signals in Strawberry Poison Frogs (Dendrobates pumilio)
Authors: Pröhl Heike , Hagemann Sabine , Karsch Jan , Höbel Gerlinde 
Published: August 2007

AbstractIn this paper, we compare the advertisement calls of 207 neotropical strawberry poison frogs (Dendrobates pumilio) collected in 21 localities along a transect from northern Costa Rica to western Panama. Populations varied most in call duration and call rate, while pulse rate and duty cycle were less variable. Multivariate analyses showed that call variation followed a cline with higher call rates, shorter calls, lower duty cycles and higher pulse rates in the southeast. Body size decreased towards the southeast and explained most variation in dominant frequency, as well as some residual variation in call rate. We conclude that a combination of geography and morphology is largely responsible for call variation within this species. Two inferred bio‐acoustic groups were roughly in accordance with two genetic groups, geographically separated in central Costa Rica. However, genetic distances among populations did not co‐vary with call dissimilarity after correction for geographic distances. Thus, differences in calls between genetic groups are probably mainly a result of clinal variation. These findings agree with the general observation that bio‐acoustic variation is often not (highly) associated with genetic divergence. Moreover, colour polymorphism observed among Panamanian populations was not reflected in a higher variability in call parameters relative to the monomorphic Costa Rican populations.
CHRONIC SUPPLEMENTATION OF CREATINE AND VITAMINS C AND E INCREASES SURVIVAL AND IMPROVES BIOCHEMICAL PARAMETERS AFTER DOXORUBICIN TREATMENT IN RATS
Authors: Santos Ronaldo VT , Batista Miguel L , Caperuto Érico C , Costa Rosa Luis FBP 
Published: August 2007

SUMMARY

Doxorubicin is an anti‐cancer drug with well‐described effects against a wide range of tumours. However, doxorubicin also exhibits dose‐dependent cytotoxicity. The purpose of the present study was to determine whether chronic supplementation of creatine or a mix of vitamins C and E could increase survival and improve plasma parameters 48 h after doxorubicin treatment.
Rats were divided into four groups: (i) saline (control); (ii) doxorubicin treated; (iii) a creatine (0.2 g/kg per day)‐supplemented group; and (iv) a vitamin C (250 mg/kg per day) and E (400 IU/kg per day)‐supplemented group. After 30 days supplementation of rats with either creatine or the vitamins, one dose of doxorubicin (15 mg/kg, i.p.) was administered.
There was no difference in weight loss among the groups until the 3rd day after doxorubicin treatment, but the creatine‐ and vitamin‐supplemented groups lived longer compared with the doxorubicin only treated group (6, 7 and 3 days, respectively). The doxorubicin‐treated group lost 13.4% bodyweight over 3 days, whereas the creatine‐ and vitamin‐supplemented groups lost approximately 35% 3 days after the administration of doxorubicin. Doxorubicin treatment resulted in an increase in alanine aminotransferase (ALT; P < 0.05), lactate dehydrogenase (LDH; P < 0.05), urea (P < 0.05) and creatinine (P < 0.05) compared with levels observed in the control group. Conversely, creatine supplementation promoted a partial return to control values for LDH (P < 0.05) and creatinine (P < 0.05), whereas the vitamin mix reversed the changes in ALT (P < 0.05), LDH (P < 0.05), urea (P < 0.05) and creatinine (P < 0.05).
In conclusion, the results of the present study indicate that the two supplementation protocols decreased the cytotoxic effects of doxorubicin and that a protective effect was more noticeable in animals supplemented with the mixture of vitamins C and E.
EFFECT OF THE HEME OXYGENASE INDUCER HEMIN ON BLOOD HAEMOSTASIS MEASURED BY HIGH‐FREQUENCY ULTRASOUND
Authors: Rochefort Gaël Y , Libgot Rachel , Desbuards Nicolas , Schlecht Deborah , Halimi Jean‐Michel , Ossant Frederic , Eder Veronique , Antier Daniel 
Published: August 2007

SUMMARY

Heme compounds, like hemin, a heme oxygenase‐1 inducer, are used in the treatment of acute porphyria treatment. The side‐effects of hemin on haemostasis have been reported. To address those effects, in the present study we used a sensitive, high‐frequency ultrasound technique to record acoustic velocity and to investigate whole blood clotting in Wistar rats treated chronically with hemin (50 mg/kg per day).
The hemin‐induced disturbances in haemostasis measured were comparable to the heparin reference treatment, with a significant decrease in clotting velocity in both groups compared with controls (e.g. the time to clot was 40 ± 5, 53 ± 13 and 10 ± 2 min, respectively; P < 0.05). Precautions must be taken when using high doses of hemin or in the treatment of bleeding diseases.
Further investigations are required to explore the effects of hemin in thrombosis models, because it could be a promising ‘old drug’ for the treatment of venous thrombosis in patients.
GLUTAMATE RECEPTOR PLASTICITY AT EXCITATORY SYNAPSES IN THE BRAIN
Authors: Genoux David , Montgomery Johanna M 
Published: August 2007

SUMMARYSynapse plasticity, defined as an activity dependent change in the strength of synapses, was first described in 1973 and, since those seminal experiments were reported, the field of synapse plasticity has expanded into one of the most widely studied areas in neuroscience.Significant effort has been focused on determining the expression mechanisms of the changes in synapse strength. The present review will focus on the changes in the post‐synaptic expression of glutamate receptors that have been shown to occur during the expression of synapse plasticity.Biochemical studies of excitatory synapses in the central nervous system have revealed a high density of proteins concentrated at dendritic spines. These proteins appear to play critical roles in synaptic structure, plasticity and in trafficking receptors to synapses.There is growing evidence that synapse plasticity could be the cellular basis of certain forms of learning and memory. Determining the behavioural correlates of this fundamental synaptic process will continue to be addressed in current and future research.
DOES SPIKE TIMING‐DEPENDENT SYNAPTIC PLASTICITY UNDERLIE MEMORY FORMATION?
Authors: Letzkus Johannes J , Kampa Björn M , Stuart Greg J 
Published: August 2007

SUMMARY

Synaptic plasticity is thought to underlie learning and memory formation in the brain. However, how synaptic plasticity is induced during these processes remains controversial. An attractive candidate mechanism for learning at the neuronal level is spike timing‐dependent synaptic plasticity (STDP), which depends on the precise (msec) timing of the synaptic input and the post‐synaptic action potential. This temporal relationship resembles typical features of associative learning. Here, we review recent evidence suggesting that STDP is likely to underlie certain forms of learning.
First, we discuss the cellular mechanisms of STDP elucidated by in vitro experiments. A special focus is put onto aspects known to differ between in vitro preparations and the in vivo situation.
Second, we review the experimental induction of STDP in vivo, in various systems ranging from Xenopus tectum to human motor cortex.
The last part of the review addresses the question whether STDP can be induced by activity patterns occurring during normal behaviour.
We conclude that STDP is a robust phenomenon in vivo and a likely mechanism underlying sensory map plasticity in the neocortex. Further experimental evidence is required to determine whether STDP also has a role in more complex forms of learning.
INTRACELLULAR CALCIUM IN THE FERTILIZATION AND DEVELOPMENT OF MAMMALIAN EGGS
Authors: Jones Keith T 
Published: August 2007

SUMMARY

Mammalian eggs are arrested at metaphase of their second meiotic division when ovulated and remain arrested until fertilized. The sperm delivers into the egg phospholipase C (PLC) ζ, which triggers a series of Ca2+ spikes lasting several hours. The Ca2+ spikes provide the necessary and sufficient trigger for all the events of fertilization, including exit from metaphase II arrest and extrusion of cortical granules that block the entry of other sperm.
The oscillatory Ca2+ signal switches on calmodulin‐dependent protein kinase II (CaMKII), which phosphorylates the egg‐specific protein Emi2, earmarking it for degradation. To remain metaphase II arrested, eggs must maintain high levels of maturation‐promoting factor (MPF) activity, a heterodimer of CDK1 and cyclin B1. Emi2 prevents loss of MPF by blocking cyclin B1 degradation, a process that is achieved by inhibiting the activity of the anaphase‐promoting complex/cyclosome. However, CaMKII is not the primary initiator in the extrusion of cortical granules.
Ca2+ spiking is also observed in mitosis of one‐cell embryos, probably because PLCζ contains a nuclear localization signal and so is released into the cytoplasm following nuclear envelope breakdown. The function of these mitotic Ca2+ spikes remains obscure, although they are not absolutely required for passage through mitosis.
Intriguingly, the pattern of Ca2+ spikes observed at fertilization has an effect on both pre‐ and postimplantation development in a manner that is independent of their ability to activate eggs. This suggests that the Ca2+ spikes set in train at fertilization are having effects on processes initiated in the newly fertilized egg but whose influences are only observed several cell divisions later. The nature of the signals remains little explored, but their importance is clear and so warrants further investigation.
COMBUSTION‐DERIVED NANOPARTICLES: MECHANISMS OF PULMONARY TOXICITY
Authors: BéruBé Kelly , Balharry Dominique , Sexton Keith , Koshy Lata , Jones Tim 
Published: August 2007

SUMMARY

The general term ‘nanoparticle’ (NP) is used to define any particle less than 100 nm in at least one dimension and NPs are generally classified as natural, anthropogenic or engineered in origin. Anthropogenic, also referred to as ‘ultrafine’ particles (UFPs), are predominately combustion derived and are characterized by having an equivalent spherical diameter less than 100 nm.
These particles, considered to be ‘combustion‐derived nanoparticles’ (CDNPs), are of toxicological interest given their nanosized dimensions, with properties not displayed by their macroscopic counterparts.
The pulmonary deposition efficiency of inhaled UFPs, along with their large surface areas and bound transition metals, is considered important in driving the emerging health effects linked to respiratory toxicity.
The toxicology of CDNPs is currently used to predict the health outcomes in humans following exposure to manufactured NPs. Their similar physicochemistry would suggest similar adverse health effects (i.e. pulmonary (and perhaps cardiac) toxicity). As such, it is essential to fully understand CDNP nanotoxicology in order to minimize occupational and environmental exposure.
POTENTIATION OF 3,4‐METHYLENEDIOXYMETHAMPHETAMINE‐INDUCED 5‐HT RELEASE IN THE RAT SUBSTANTIA NIGRA BY CLORGYLINE, A MONOAMINE OXIDASE A INHIBITOR
Authors: Hewton Ryan , Salem Abdallah , Irvine Rodney J 
Published: August 2007

SUMMARY

It is well established that the commonly used recreational drugs 3,4‐methylenedioxymethamphetamine (MDMA, ‘ecstasy’) and para‐methoxyamphetamine (PMA) facilitate the release and prevent the reuptake of 5‐hydroxytryptamine (5‐HT, serotonin). Although these drugs have similar potencies for their abilities to increase the release and inhibit the re‐uptake of 5‐HT, PMA has greater potency as an inhibitor of monoamine oxidase (MAO)‐A.
The present study compared the abilities of PMA and MDMA to increase extracellular 5‐HT concentrations in animals with functional MAO‐A and when MAO‐A activity was inhibited by clorgyline.
Samples of extracellular fluid from rat substantia nigra were collected using microdialysis and then analysed for 5‐HT and 5‐hydroxyindol acetic acid (5‐HIAA) by high‐performance liquid chromatography coupled with electrochemical detection. The 5‐HT‐mediated effects on body temperature and behaviour were also recorded. Rats were pretreated with saline or 10 mg/kg, i.p., clorgyline and, 24 h later, injected with 10 mg/kg MDMA, PMA or saline.
Both MDMA and PMA produced significant increases in extracellular 5‐HT concentrations (482 ± 83 and 726 ± 287%, respectively; P < 0.05). Rats treated with PMA and MDMA displayed significantly increased 5‐HT‐related behavours (P < 0.05). Furthermore, only MDMA was capable of producing additional significant increases in 5‐HT concentrations (1033 ± 131%; P < 0.01) when coadministered with clorgyline.
The results of the present study suggest that PMA and MDMA are similar in their abilities to increase extracellular 5‐HT levels in animals with functional MAO‐A activity. However, coadministration of these substituted amphetamines with an MAO‐A inhibitor causes significant potentiation in the ability to increase extracellular levels of 5‐HT for MDMA, but not PMA.
METHYLENE BLUE INCREASES CONTRALATERAL TESTICULAR ISCHAEMIA–REPERFUSION INJURY AFTER UNILATERAL TESTICULAR TORSION
Authors: Inan Mustafa , Basaran Umit N , Dokmeci Dikmen , Yalcin Omer , Aydogdu Nurettin , Turan Nesrin 
Published: August 2007

SUMMARY

Testicular ischaemia–reperfusion injury is commonly seen in childhood. Infertility occurs in 25% of patients after unilateral testicular ischaemia. It is has been reported that methylene blue has a positive effect in the reparation of ischaemia–reperfusion injury in different tissues. Therefore, we hypothesized that methylene blue may prevent the hazardous effects of ischaemia–reperfusion injury in testicular tissue after unilateral testicular torsion.
Thirty‐two prepubertal Wistar‐albino rats were divided into four groups. Testicular torsion was created by rotating the right testis 720° in a clockwise direction for 5 h in all groups except for Group C, which was the sham control group. In Group T, bilateral orchiectomy was performed following the torsion period. In Group TD, both testes were removed 5 days after the torsion period. In Group MB, methylene blue (1 mg/kg, i.p.) was administered 40 min before detorsion and once daily over 5 days; then, both testes were harvested. Tissue levels of malondialdehyde (MDA), serum levels of creatine kinase (CK), mean testicular biopsy score (MTBS) and mean seminifer tubule diameter (MSTD) were determined.
There was a significant difference in MTBS between Groups T and TD (P < 0.05) in both ipsilateral and contralateral testes. In the contralateral testis, treatment with methylene blue decreased MTBS and MSTD (P < 0.05) and increased MDA levels (P < 0.05). In Group T, mean serum CK concentrations were higher than in any of the other groups (P < 0.05).
After 5 h of unilateral testicular torsion and a 5 day reperfusion period, serious tissue damage occurred on both the ipsilateral and contralateral sides. Serum CK concentrations may be an indicator for ischaemia, but not for ischaemia–reperfusion injury. Contrary to our hypothesis, methylene blue increased contralateral testicular damage after unilateral testicular torsion and exacerbated oxidative events.