Anatomy and histochemistry of spread-wing posture in birds. 2. Gliding flight in the California Gull,Larus californicus: A paradox of fast fibers and posture

Gliding flight is a postural activity which requires the wings to be held in a horizontal position to support the weight of the body. Postural behaviors typically utilize isometric contractions in which no change in length takes place. Due to longer actin-myosin interactions, slow contracting muscle fibers represent an economical means for this type of contraction. In specialized soaring birds, such as vultures and pelicans, a deep layer of the pectoralis muscle, composed entirely of slow fibers, is believed to perform this function. Muscles involved in gliding posture were examined in California gulls (Larus californicus) and tested for the presence of slow fibers using myosin ATPase histochemistry and antibodies. Surprisingly small numbers of slow fibers were found in the M. extensor metacarpi radialis, M. coracobrachialis cranialis, and M. coracobrachialis caudalis, which function in wrist extension, wing protraction, and body support, respectively. The low number of slow fibers in these muscles and the absence of slow fibers in muscles associated with wing extension and primary body support suggest that gulls do not require slow fibers for their postural behaviors. Gulls also lack the deep belly to the pectoralis found in other gliding birds. Since bird muscle is highly oxidative, we hypothesize that fast muscle fibers may function to maintain wing position during gliding flight in California gulls. J. Morphol. 233:237–247, 1997. © 1997 Wiley-Liss, Inc.     

Direct Angiotensin AT2 Receptor Stimulation Using a Novel AT2 Receptor Agonist,Compound 21, Evokes Neuroprotection in Conscious Hypertensive Rats

Background

In this study, the neuroprotective effect of a novel nonpeptide AT2R agonist, C21, was examined in a conscious model of stroke to verify a class effect of AT2R agonists as neuroprotective agents.

Methods and Results

Spontaneously hypertensive rats (SHR) were pre-treated for 5 days prior to stroke with C21 alone or in combination with the AT2R antagonist PD123319. In a separate series of experiments C21 was administered in a series of 4 doses commencing 6 hours after stroke. A focal reperfusion model of ischemia was induced in conscious SHR by administering endothelin-1 to the middle cerebral artery (MCA). Motor coordination was assessed at 1 and 3 days after stroke and post mortem analyses of infarct volumes, microglia activation and neuronal survival were performed at 72 hours post MCA occlusion. When given prior to stroke, C21 dose dependently decreased infarct volume, which is consistent with the behavioural findings illustrating an improvement in motor deficit. During the pre-treatment protocol C21 was shown to enhance microglia activation, which are likely to be evoking protection by releasing brain derived neurotrophic factor. When drug administration was delayed until 6 hours after stroke, C21 still reduced brain injury.

Conclusion

These results indicate that centrally administered C21 confers neuroprotection against stroke damage. This benefit is likely to involve various mechanisms, including microglial activation of endogenous repair and enhanced cerebroperfusion. Thus, we have confirmed the neuroprotective effect of AT2R stimulation using a nonpeptide compound which highlights the clinical potential of the AT2R agonists for future development.     

An extensive analysis of the African rice genetic diversity through a global genotyping

Key message

We present here the first curated collection of wild and cultivated African rice species. For that, we designed specific SNPs and were able to structure these very low diverse species.

Abstract

Oryza glaberrima, the cultivated African rice, is endemic from Africa. This species and its direct ancestor, O. barthii, are valuable tool for improvement of Asian rice O. sativa in terms of abiotic and biotic stress resistance. However, only a few limited studies about the genetic diversity of these species were performed. In the present paper, and for the first time at such extend, we genotyped 279 O. glaberrima, selected both for their impact in current breeding and for their geographical distribution, and 101 O. barthii, chosen based on their geographic origin, using a set of 235 SNPs specifically designed for African rice diversity. Using those data, we were able to structure the individuals from our sample in three populations for O. barthii, related to geography, and two populations in O. glaberrima; these two last populations cannot be linked however to any currently phenotyped trait. Moreover, we were also able to identify misclassification in O. glaberrima as well as in O. barthii and identified new form of O. sativa from the set of African varieties.     

LINNAEUS: A species name identification system for biomedical literature

Background  

The task of recognizing and identifying species names in biomedical literature has recently been regarded as critical for a number of applications in text and data mining, including gene name recognition, species-specific document retrieval, and semantic enrichment of biomedical articles.     

Plasma profiling reveals human fibulin-1 as candidate marker for renal impairment

There is a need for reliable and sensitive biomarkers for renal impairments to detect early signs of kidney toxicity and to monitor progression of disease. Here, antibody suspension bead arrays were applied to profile plasma samples from patients with four types of kidney disorders: glomerulonephritis, diabetic nephropathy, obstructive uropathy, and analgesic abuse. In total, 200 clinical renal-associated cases and control plasma samples from different cohorts were profiled. Parallel plasma protein profiles were obtained using biotinylated and nonfractionated samples and a selected set of 94 proteins targeted by 129 antigen-purified polyclonal antibodies. Out of the analyzed target proteins, human fibulin-1 was detected at significantly higher levels in the glomerulonephritis patient group compared to the controls and with elevated levels in patient samples for all other renal disorders investigated. Two polyclonal antibodies and one monoclonal antibody directed toward separate, nonoverlapping epitopes showed the same trend in the discovery cohorts. A technical verification using Western blot analysis of selected patient plasma confirmed the trends toward higher abundance of the target protein in disease samples. Furthermore, a verification study was carried out in the context of glomerulonephritis using an independent case and control cohort, and this confirmed the results from the discovery cohort, suggesting that plasma levels of fibulin-1 could serve as a potential indicator to monitor kidney malfunction or kidney damage.     

The Role of <Emphasis Type="Italic">Habitus</Emphasis> in the Maintenance of Traditional Noongar Plant Knowledge in Southwest Western Australia

We examine the role that habitus, an individual’s or group’s dispositions, has played in the retention of traditional ecological knowledge among the Noongar people of south-western Australia. We sought to determine if current plant knowledge reflects Noongar habitus or, alternatively, the use of fall-back species that were important due to the intermittency of agricultural employment and the social exclusion of Aboriginal people up until at least the 1960s in Western Australia. We compared the seasonal availability of Noongar food plant resources currently known by Noongar Elders to those described at the time of European settlement. We used non-metric Multidimensional Scaling (nMDS) and multivariate statistics to compare the seasonal availability of plant resources with the seasonal availability of work prior to the introduction of civil rights for Aboriginal Australians in the 1960s. We show that the seasonal pattern of plant knowledge has changed little since settlement and that there was no significant relationship between the seasonal availability of work and plant knowledge. This result suggests that prior to 1960 Noongars maintained a reasonably traditional round of seasonal activities involving traditional plant use. We suggest that Noongar habitus guided their response to the colonising culture and helped preserve traditional ecological knowledge.     

Aerosols transmit prions to immunocompetent and immunodeficient mice

Prions, the agents causing transmissible spongiform encephalopathies, colonize the brain of hosts after oral, parenteral, intralingual, or even transdermal uptake. However, prions are not generally considered to be airborne. Here we report that inbred and crossbred wild-type mice, as well as tga20 transgenic mice overexpressing PrP(C), efficiently develop scrapie upon exposure to aerosolized prions. NSE-PrP transgenic mice, which express PrP(C) selectively in neurons, were also susceptible to airborne prions. Aerogenic infection occurred also in mice lacking B- and T-lymphocytes, NK-cells, follicular dendritic cells or complement components. Brains of diseased mice contained PrP(Sc) and transmitted scrapie when inoculated into further mice. We conclude that aerogenic exposure to prions is very efficacious and can lead to direct invasion of neural pathways without an obligatory replicative phase in lymphoid organs. This previously unappreciated risk for airborne prion transmission may warrant re-thinking on prion biosafety guidelines in research and diagnostic laboratories.     

Biological and socio-economic effects of statewide limitation of deer licenses in Colorado

We evaluated the biological and socio-economic effects of statewide limitation of mule deer (Odocoileus hemionus) hunting licenses, which began in Colorado in 1999. We implemented a before-after-control-impact (BACI) analysis of annual helicopter sex and age class surveys, collected as part of the Colorado Division of Wildlife's routine monitoring, to assess changes in adult male/adult female ratios and fawn/adult female ratios in response to this change in harvest management. Following statewide limitation and reduction of license sales (1999–2006), we observed increases in adult male/adult female ratios of 7.39 (SE = 2.36) to 15.23 (SE = 1.22) adult males per 100 adult females in moderately limited areas and of 17.55 (SE = 3.27) to 21.86 (SE = 2.31) adult males per 100 adult females in highly limited areas. We simultaneously observed reductions in fawn/adult female ratios in newly limited areas by as much as 6.96 (SE = 2.19) fawns per 100 females, whereas in areas that had previously been limited we observed stabilization of fawn/adult female ratios at levels lower than levels observed under the unlimited harvest management structure. An immediate decline of $7.86 million in annual revenue stemmed from the change in harvest management, but revenue subsequently rebounded. This study provides preliminary evidence of potential effects that other state and provincial wildlife management agencies may face as they consider shifting mule deer harvest management towards limited license scenarios. © 2011 The Wildlife Society.