bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth and development in six species of African mole‐rats (Rodentia: Bathyergidae)
Authors: Bennett N. C. , Jarvis J. U. M. , Aguilar G. H. , McDaid E. J. 
Published: March 2009

The bathyergid mole‐rats provide a unique example of a family of subterranean rodents exhibiting a broad spectrum of sociality. Three genera comprise solitary, strongly territorial individuals whereas two genera are social. This sociality culminates in the eusocial naked mole‐rat, Heterocephalus glaber. The pups of solitary mole‐rats disperse, establish and thereafter defend their own burrow systems when approximately two months old, whereas those of social genera join an established natal colony. This paper examines whether these different lifestyles are reflected in the early development and rate of growth of pups of mole‐rats.Although the trends are not clear‐cut, it is apparent that the pups of solitary genera grow and mature more rapidly than those from social genera. Thus, the growth rate constant (K) for the first70–80 days of postnatal growth (using the Gompertz equation) for the solitary genera was between 0.042 and 0.052 day−1, whereas that of the social mole‐rats was considerably lower (0.01 5 day−1). Similarly the mean growth rates of solitary genera ranged between 3.3 and 1.227g/day while those of the social mole‐rats were 0.229‐0.233 g/day.The pattern of development and the rates of growth in solitary bathyergids are similar to those of other solitary subterranean rodents. One interesting feature common to all the social genera studied to date was that the first pups recruited to a ‘new colony’, consisting of a reproductive pair of adult mole‐rats, grew at a significantly faster rate than pups born to an established colony.
Detection of two coexisting species of Oxystele (Gastropoda: Trochidae) by morphological and electrophoretic analyses
Authors: Heller Joseph , Dempster Yvonne 
Published: March 2009

Oxystele variegata (Anton, 1838) is one of the commonest intertidal topshells on the coast of South Africa. In this study we show that the so‐called O. variegata actually consists of two sympatric species, which differ in shell colour patterns, in the proportions of the central tooth of the radula, and in the electrophoretic mobilities of some enzymes: O. impervia (Menke, 1843) (which tends to occur higher up the shore), and O. variegata (Anton, 1838) (occurring further down the shore).The shell of O. impervia has a pattern of dark red, orange, yellow or brown maculations, on a ground colour that is red, orange, yellow or brown, respectively; that of O. variegata has a pattern of red maculations or lines on a ground colour that is either off‐white, or greenish‐grey. Both O. impervia and O. variegata exhibit an immense variety of shell colours and pattern and in both, shell colour variation is an interplay between two factors: ground colour and maculated spiral bands. By expanding the maculated spiral bands in breadth, at the expense of the ground colour, an original shell pattern of spiral bands may be transformed into one of axial or diagonal stripes.The radula of both species resemble the typical trochid pattern. They are, however, consistently different: the central tooth of the radula of O. imperial usually has a shallow base and a cusp that is slightly indented, whereas that of O. variegata usually has a deep base, and a well indented cusp.Further differences between the species were revealed by electrophoretic studies. Of six loci examined, two were found to be taxonomically diagnostic. Another two had at least one species‐specific allele at a frequency of 0·1 or greater, and significant heterogeneity in allelic frequency between the two species was found in the four non‐diagnostic loci.The differences in shell colour patterns, radular tooth structure and enzyme mobilities support the conclusion that O. impervia and O. variegata are separate but closely related species, with similar geographic distributions and an overlapping zonation.
Hepatozoon in grey squirrels (Sciurus carolinensis) trapped near Reading, Berkshire
Authors: Watkins Barbara M. , Nowell F. 
Published: March 2009

Hepatozoon infections of Sciurus carolinensis were investigated by a 30‐month capture/recapture trapping programme. Details of trapping methods, squirrel husbandry and blood sampling techniques are discussed. Hepatozoon gametocytes infected blood monocytes and could be detected in blood smears or by concentration of leucocytes. From blood smears, 71% (154/218) of the squirrels were infected. Prevalence appeared to be influenced by host hormonal and breeding patterns. Significantly more adult males than adult females were infected (P<0.025). Infections were significantly more prevalent in adults overall and in adult males than in juvenile males (P< 0.001 in both cases), but not significantly different between female adults and juveniles (P>0.05). Prevalence rates were generally higher: (i) in summer and winter, when animals mate, compared to spring and autumn; and (ii) in 1984 than in 1983, possibly relating to differences of squirrel breeding success and juvenile recruitment in the two years. Parasitaemias were overdispersed in the sampled host population and significantly lower in females (38%) than in males (48%) (P<0.05), although there was no significant difference between the age classes. Animals, either recaptured or laboratory‐maintained, showed chronic fluctuating parasitaemias with no obvious pattern. Squirrels with overt parasitaemias showed trophozoites and schizogonic stages of Hepatozoon in the lung and rarely in liver and spleen. Three out of 16 animals with no obvious parasitaemias had lung tissue stages of the parasite. Results suggest that Hepatozoon is more prevalent in grey squirrel populations than blood smears suggest.
Seasonal shifts within juvenile recruit sex ratio of Pampas mice (Akodon azarae)
Authors: Zuleta G. A. , Bilenca D. N. 
Published: March 2009

Sex ratio (SR) variation of Akodon azarae juvenile recruits was analysed during 1985–86 on a Pampean grassland in central Argentina. Rodents were intensively live‐trapped on a 0.81 ha grid. The SR (proportion of males) of the overall population did not differ significantly from evenness (0.49). In contrast, juvenile recruits (0.5–2.0 months of age) showed SR fluctuations according to their time of birth. SR was strongly female‐biased among spring and autumn juveniles (0.13 and 0.33, respectively), while males were predominant (0.72) among the summer juveniles.Social and demographic implications of these results are discussed in the framework of current SR theory. Spring female recruits should be selected for summer reproduction and autumn female recruits for winter survival and spring reproduction. The overwintered population was characterized by 1:1 SR and an age structure composed of males older than females. Most of these males had been recruited as juveniles during the summer. They also made up most of the resident male population in the spring. A selective allocation of energy by the mothers among their offspring is the mechanism proposed to explain the seasonal changes in SR, as pregnant females which gave birth to the summer recruits were in better physical condition than the mothers of both spring and autumn recruits. These results are consistent with the predictions of Werren & Charnov (1978), based on temporal overproduction of one or the other sex according to differential changes in the life‐history expectations for both sexes.
The effects of pH, aluminium concentration and temperature on the embryonic development of the European common frog, Rana temporaria
Authors: Beattie R. C. , Tyler‐.Tones R. , Baxter M. J. 
Published: March 2009

The individual and combined effects of pH, aluminium concentration and temperature, on the development of common frog (Rana temporaria) embryos from an upland area of northern England, were investigated in a controlled laboratory study. There was strong evidence to suggest that embryonic survival was lower at pH 4.5 compared with pH 6.0. At pH 4.5, embryonic survival was reduced at the highest aluminium concentrations. There was no strong evidence for a reduction in embryonic survival at lower aluminium concentrations.Gastrulation and hatching appeared to be the most sensitive stages to both pH and aluminium concentration.There was strong evidence to suggest that temperature‐shocked embryos had reduced survival when compared with those kept at a constant temperature, particularly at pH 4.5.There was substantial variation in the survival of embryos from different clutches in the same pond with respect to low pH, aluminium concentration and temperatures. Thus R. temporaria has a wide genetic base from which to tolerate environmental changes. It is suggested, however, that the lethal and sublethal effects of low pH, high aluminium concentration and low temperature, could lead to a decrease in recruitment to the adult populations of R. temporaria in upland, northern England.
Morphometric estimation of oxygen diffusing capacity for the air‐sac in the catfish Heteropneustes fossilis
Authors: Hughes G. M. , P. K. Roy  , Munshi J. S. D. 
Published: March 2009

A detailed morphometric study has been made of the air‐sacs of this air‐breathing catfish using whole mounts, light and electron microscopy, of six specimens, body weight 40±2 g. Measurements of surface areas of the gas exchange and non‐respiratory surfaces have taken into account foldings of the surface at macro and ultramicroscopic levels. Area of the gas exchange surface was estimated as 23.915cm2 (=0.598cm2/g) which is 67%of the total surface area of the two air‐sacs. Significant differences were found in some morphometric parameters which were related to the three antero‐posterior regions into which air‐sacs were divided. Harmonic mean thickness of the tissue component of the air/blood barrier was estimated for the whole air‐sac as 0.342 μm. These and other measurements enabled the diffusing capacity for the air‐sacs to be calculated as 0.0638 m1O2/min/mmHg/kg.These results show that Heteropneustes has an air‐breathing organ which is superior to that of Amphipnous cuchia, similar to that of Lepidosiren, but less well developed than that of Protopterus. In addition, Heteropneustes is well adapted to obtain oxygen directly from water by means of its gills and skin as indicated by both morphometric and physiological measurements which also correlate with its life in ponds and streams which are Iiable to dry up.
How the ‘forceps’ of Lithophaga aristata (Bivalvia: Mytiloidea) are formed
Authors: Morton Brian 
Published: March 2009

The calcareous substratum borer, Lithopaga aristata Dillwyn, 1817, secretes posterior incrustations that take the form of interlocking ‘forceps’. These are secreted, initially, as asymmetrical ridges by similarly asymmetrical dorsal and ventral glands in the left and right middle folds of the posterior mantle lobes. In the adult, the secretions are more uniformly spread over the posterior shell margins, concealing the juvenile ridges.Opening and closing of the valves smooths the outer surfaces of the ‘forceps’ against the burrow wall, which also comes to be lined with calcium carbonate that is reciprocally smoothed, so that they occlude the borehole more effectively. Extension and retraction of the siphons probably smooths the inner surfaces of the ‘forceps’ which are sharpened by abrasion, one against the other, during valve opening and closing. The pair of inequilateral spikes so produced, project from the burrow aperture, occluding it, but probably, more importantly, distancing aperturally attacking predators from the true posterior shell margin. Interlocking of the ‘forceps’ and their sharpness may further deter would‐be predators.
Fostering in an African rodent, Saccostomus campestris (Cricetidae)
Authors: Westlin Lilina M. 
Published: March 2009

Fostering was studied in females of an African rodent Saccostomus campestris, the pouched mouse, which, contrary to most other rodents, is a solitary species. Females will only tolerate their own offspring and other adults are viciously attacked at all times except during the short period of pro‐oestrus, when a male will be temporarily accepted.Alien pups (n = 857) of different age‐groups (0–30 days) were introduced to lactating females (n = 191) with their own pups (n = 1053) of different age‐groups (0–20 days) over a period of three years. The total number of pups per female was made up to 10 (e.g. 7 own + 3 alien or 4 own + 6 alien).The ‘foster mother’ readily accepted and successfully reared alien pups provided they were less than 21 days of age when introduced. Weaned alien pups, introduced when 25 or 30 days old, were viciously attacked by the foster mother and had to be removed, althoughin the breeding colony, pups that were allowed to remain with their mother after weaning were not attacked. It appears that up to weaning‐age, female Saccostomus campestris may not distinguish between may not distinguis between their own and alien offspring, but rather between suckling and weaned pups.
Visual perceptual load modulates an auditory microreflex
Authors: Parks Nathan A. , Hilimire Matthew R. , Corballis Paul M. 
Published: March 2009

AbstractThe postauricular reflex (PAR) is a vestigial microreflex evoked by an abrupt auditory onset. Previous studies have indicated that the PAR is unaffected by auditory selective attention. Here, we report that the PAR can be modulated by a crossmodal manipulation of attentional demands within the visual modality. Subjects (N=17) performed a central rapid serial visual presentation (RSVP) task while presented with irrelevant auditory distractor probes that elicited the PAR. Visual attentional demands were manipulated by altering the perceptual load of the RSVP task. The PAR modulated systematically with perceptual load, decreasing in amplitude with increased perceptual load. Results indicate that the PAR can be influenced by attention, at least within the visual modality.
Twenty years of cell‐penetrating peptides: from molecular mechanisms to therapeutics
Authors: Heitz Frederic , Morris May Catherine , Divita Gilles 
Published: March 2009

The recent discovery of new potent therapeutic molecules that do not reach the clinic due to poor delivery and low bioavailability have made of delivery a key stone in therapeutic development. Several technologies have been designed to improve cellular uptake of therapeutic molecules, including cell‐penetrating peptides (CPPs). CPPs were first discovered based on the potency of several proteins to enter cells. Numerous CPPs have been described so far, which can be grouped into two major classes, the first requiring chemical linkage with the drug for cellular internalization and the second involving formation of stable, non‐covalent complexes with drugs. Nowadays, CPPs constitute very promising tools for non‐invasive cellular import of cargo and have been successfully applied forin vitroandin vivodelivery of therapeutic molecules varying from small chemical molecule, nucleic acids, proteins, peptides, liposomes and particles. This review will focus on the structure/function and cellular uptake mechanism of CPPs in the general context of drug delivery. We will also highlight the application of peptide carriers for the delivery of therapeutic molecules and provide an update of their clinical evaluation.This article is part of a themed section on Vector Design and Drug Delivery. For a list of all articles in this section see the end of this paper, or visit:http://www3.interscience.wiley.com/journal/121548564/issueyear?year=2009
Different response patterns of several ligands at the sphingosine‐1‐phosphate receptor subtype 3 (S1P3)
Authors: Jongsma M , Van Unen J , Van Loenen PB , Michel MC , Peters SLM , Alewijnse AE 
Published: March 2009

Background and purpose:  Recently, some ligands targeting the sphingosine‐1‐phosphate receptor subtype 3 (S1P3) have become available. The characterization of these compounds was mainly based on one functional read‐out system, although S1P3 receptors are known to activate different signal transduction pathways. Therefore, this study pharmacologically characterizes these compounds using different assays.Experimental approach:  Using CHO‐FlpIn cells expressing the human S1P3 receptor the potencies and maximal effects of S1P, FTY720‐P, VPC23019, VPC23153 and VPC24191 were determined in three different assays [inhibition of cAMP accumulation, elevation of intracellular calcium concentrations ([Ca2+]i) and S1P3 receptor internalization].Key results:  All compounds tested inhibited forskolin‐induced cAMP accumulation, increased [Ca2+]i and induced S1P3 receptor internalization but with different potencies and maximal effects. S1P was the most potent compound in all assays followed by FTY720‐P. The VPC compounds were generally less potent than S1P and FTY720‐P. Regarding the maximal effects, all compounds except VPC23153, behaved as full agonists in the cAMP accumulation assay. In the calcium assay, FTY720‐P, VPC23019 and VPC24191 displayed partial and VPC23153 weak partial agonist activity, relative to S1P. Interestingly, treatment with the Gi inactivator Pertussis toxin, did not affect S1P‐induced [Ca2+]i elevations but inhibited those in response to the other compounds, by about 50%.Conclusions and implications:  This study demonstrated differential response patterns at the S1P3 receptor for a range of ligands. These differences could indicate the presence of functional selectivity at this receptor as FTY720‐P and the VPC compounds seemed to signal predominantly via Gi– whereas S1P activated Gi and Gq‐coupled pathways.
Mechanism of action of species‐selective P2X7receptor antagonists
Authors: Michel Anton D , Ng Sin‐Wei , Roman Shilina , Clay William C , Dean David K , Walter Daryl S 
Published: March 2009

Background and purpose: AZ11645373 andN‐{2‐methyl‐5‐[(1R, 5S)‐9‐oxa‐3,7‐diazabicyclo[3.3.1]non‐3‐ylcarbonyl]phenyl}‐2‐tricyclo[3.3.1.13,7]dec‐1‐ylacetamide hydrochloride (compound‐22) are recently described P2X7receptor antagonists. In this study we have further characterized these compounds to determine their mechanism of action and interaction with other species orthologues.Experimental approach: Antagonist effects at recombinant and chimeric P2X7receptors were assessed by ethidium accumulation and radioligand‐binding studies.Key results: AZ11645373 and compound‐22 were confirmed as selective non‐competitive antagonists of human or rat P2X7receptors respectively. Both compounds were weak antagonists of the mouse and guinea‐pig P2X7receptors and, for each compound, their potency estimates at human and dog P2X7receptors were similar. The potency of compound‐22 was moderately temperature‐dependent while that of AZ11645373 was not. The antagonist effects of both compounds were slowly reversible and were not prevented by decavanadate, suggesting that they were allosteric antagonists. Indeed, the compounds competed for binding sites labelled by an allosteric radio‐labelled P2X7receptor antagonist. The species selectivity of AZ11645373, but not compound‐22, was influenced by the nature of the amino acid at position 95 of the P2X7receptor.N2‐(3,4‐difluorophenyl)‐N1‐[2‐methyl‐5‐(1‐piperazinylmethyl)phenyl]glycinamide dihydrochloride, a positive allosteric modulator of the rat receptor, reduced the potency of compound‐22 at the rat receptor but had little effect on the actions of AZ11645373.Conclusions: AZ11645373 and compound‐22 are allosteric antagonists of human and rat P2X7receptors respectively. The differential interaction of the two compounds with the receptor suggests there may be more than one allosteric regulatory site on the P2X7receptor at which antagonists can bind and affect receptor function.
Quantitative estimate of the risks and benefits of possible alternative blood donor deferral strategies for men who have had sex with men
Authors: Anderson Steven A. , Yang Hong , Gallagher Lou M. , O'Callaghan Sharon , Forshee Richard A. , Busch Michael P. , McKenna Matthew T. , Williams Ian , Williams Alan , Kuehnert Matthew J. , Stramer Susan , Kleinman Steve , Epstein Jay , Dayton Andrew I. 
Published: March 2009

BACKGROUND: Implementation of sensitive screening methods for human immunodeficiency virus (HIV) and hepatitis viruses prompts the question of what quantitative risks may result from altered deferral strategies for donation of blood by men who have had sex with men (MSM).STUDY DESIGN AND METHODS: Quantitative probabilistic models were developed to assess changes in the residual risk of transfusion‐transmitted HIV and hepatitis B virus (HBV) associated with blood testing and quarantine release errors (QREs) in the initial year of two hypothetical policy scenarios that would allow donations from donors who have abstained from MSM behavior for at least 5 years (MSM5) or at least 1 year (MSM1).RESULTS: The MSM5 and MSM1 models, respectively, predicted annual increases in units of HIV‐infected blood of 0.5% (0.03 mean additional units; 95% confidence interval [CI], 0‐1) and 3.0% (0.18 mean additional units; 95% CI, 0‐1) over current estimated HIV residual risk using recent, nationwide biologic product deviation reports to estimate QRE rates. These estimates are approximately 10‐fold lower than estimates based on New York State QRE data from the previous decade. The models predicted smaller increases in infectious HBV donations.CONCLUSIONS: QREs remain the most significant preventable source of risk. More accurate inputs, including the percentage of MSM in the population, the percentage of MSM who have abstained from MSM activity for 1 or 5 years, the prevalence of HIV and HBV in MSM who have abstained from MSM activity for 1 or 5 years, the rate of self‐deferral, and QRE rates, are required before making more precise predictions.
A laboratory comparison of pathogen reduction technology treatment and culture of platelet products for addressing bacterial contamination concerns
Authors: Goodrich Raymond P. , Gilmour Denise , Hovenga Nick , Keil Shawn D. 
Published: March 2009

BACKGROUND: Concerns over the risk of bacterial contamination of platelet products have led to implementation of bacteria culture and other screening methods. New approaches for dealing with this issue have also been proposed.STUDY DESIGN AND METHODS: A direct comparison of treatment with riboflavin and ultraviolet (UV) light (Mirasol pathogen reduction technology [PRT] system) versus bacterial culture testing (two‐bottle system, 48‐hour quarantine) was undertaken to compare their effectiveness. Thirteen clinically relevant bacterial organisms (20 strains) were used in this evaluation. Results were compared with spiking levels at 20 to 100 colony‐forming units (CFUs) per product and at less than 20 CFUs per product.RESULTS: At spiking levels of 20 to 100 CFUs per product, the riboflavin and UV light process demonstrated 91% effectiveness against a broad spectrum of bacteria. In comparison, the culture method demonstrated an ability to detect up to 91% of the same contaminants, when used in the two‐bottle, 48‐hour‐to‐release configuration. At lower initial titers of contaminating agents (<20 CFUs per product), the effectiveness of PRT increased to 98% whereas the culture method effectiveness decreased to 66%. Effectiveness of the culture method further decreased to 60% when a one‐bottle system was used.CONCLUSION: The results from this work suggest that the riboflavin and UV light process may provide up to 98% protection against transfusion of bacterially contaminated units at the most clinically relevant contamination levels (<20 CFUs per product). This compares favorably to the 60% to 66% effectiveness of bacterial culture testing using a 48‐hour quarantine period before product release.