Behaviorally measured tactile sensitivity in the common bottlenose dolphin,Tursiops truncatus

Little research has been conducted on the somatosensory system of toothed whales and it remains uncertain how tactile sensitivity varies about their bodies. In this study, tactile sensitivity to high-frequency (250-Hz) displacement of the skin was quantified in three trained adult common bottlenose dolphins (Tursiops truncatus) using a vibratory device (tactor). The magnitude of skin displacement was controlled by varying the voltage to the tactor held against the skin surface with a constant force. Tactile thresholds were determined using an adaptive method of limits in which dolphins reported perception of the tactile stimulus by producing a whistle. Displacement thresholds ranged from 2.4 to 40 μm, with the greatest sensitivity found along the rostrum, melon, and blowhole. Sensitivity decreased caudally along the body, with the dorsal fin and tip of the fluke being the least sensitive locations tested. The results support hypotheses that the follicles on the dolphin rostrum are particularly important for perception. The reduction in tactile sensitivity at the appendages is consistent with their primary role in stabilization and locomotion compared to exploration or environmental sensing.     

An Inexpensive,Scalable Behavioral Assay for Measuring Ethanol Sedation Sensitivity and Rapid Tolerance in Drosophila

Alcohol use disorder (AUD) is a serious health challenge. Despite a large hereditary component to AUD, few genes have been unambiguously implicated in their etiology. The fruit fly, Drosophila melanogaster, is a powerful model for exploring molecular-genetic mechanisms underlying alcohol-related behaviors and therefore holds great promise for identifying and understanding the function of genes that influence AUD. The use of the Drosophila model for these types of studies depends on the availability of assays that reliably measure behavioral responses to ethanol. This report describes an assay suitable for assessing ethanol sensitivity and rapid tolerance in flies. Ethanol sensitivity measured in this assay is influenced by the volume and concentration of ethanol used, a variety of previously reported genetic manipulations, and also the length of time the flies are housed without food immediately prior to testing. In contrast, ethanol sensitivity measured in this assay is not affected by the vigor of fly handling, sex of the flies, and supplementation of growth medium with antibiotics or live yeast. Three different methods for quantitating ethanol sensitivity are described, all leading to essentially indistinguishable ethanol sensitivity results. The scalable nature of this assay, combined with its overall simplicity to set-up and relatively low expense, make it suitable for small and large scale genetic analysis of ethanol sensitivity and rapid tolerance in Drosophila.     

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA): experience of an academic centre in the USA

S. Zhang, D. V. S. DeFrias, R. Alasadi and R. Nayar
Endoscopic ultrasound‐guided fine needle aspiration (EUS‐FNA): experience of an academic centre in the USA Objectives: Endoscopic ultrasound‐guided fine needle aspiration (EUS‐FNA) has become widely accepted as an effective modality for obtaining tissue for primary diagnosis and staging. We have been using EUS‐FNA since July 2001 and herein we summarize our experience over a 5‐year period. Methods: A computer‐based search for in‐house EUS‐FNA was performed in the pathology database from July 2001 to October 2006. To calculate the sensitivity, specificity and accuracy of EUS‐FNA, the cytology diagnosis was compared with the surgical follow‐up. Results: A total of 951 EUS‐FNAs were performed during the study period and included 279 pancreatic solid lesions, 186 pancreatic cyst lesions, 249 lymph node aspirations, 111 gastrointestinal (GI) tract submucosal lesions, and 126 miscellaneous lesions. EUS‐FNA had a very high sensitivity and accuracy for solid pancreatic lesions (94.7 and 97.7%, respectively), low sensitivity and accuracy but high specificity (47, 64.8 and 95%, respectively) for cystic lesions. Cyst fluid carcinoembryonic (CEA) levels were significantly higher in mucinous neoplasms than non‐neoplastic cysts. EUS‐FNA also had very high sensitivity and specificity for detecting metastatic carcinoma in lymph nodes (95 and 100%, respectively). GI submucosal spindle cell tumours were further classified with immunohistochemical stains performed either on a cell block or a core biopsy obtained via EUS guidance. Conclusions: EUS‐FNA has a very high sensitivity and accuracy for pancreatic solid lesions, but the sensitivity for cystic lesions is generally low. Cyst fluid chemical analysis for CEA is helpful, but the overlap between mucinous neoplasm and non‐neoplastic cysts is significant. Recognizing GI contamination is important and immunohistochemical stains are useful for GI submucosal spindle cell lesions.     

Variation and the response to variation as a basis for successful cooperation

In applying game theory to problems in biology, differences between individuals are often ignored. In particular, when analysing the evolution of cooperation it is often implicitly assumed that ignoring variation will produce predictions that approximate the solution when differences are included. This need not be true. As we demonstrate, differences are not innocuous noise, but can fundamentally change the nature of a game. Even small amounts of variability can stabilize cooperation by, for example, maintaining the need to deal with cheaters. Differences promote the need to learn about others in an interaction, leading to contingent behaviour that can reduce conflict, and to negotiated outcomes that may or may not be more cooperative than unconditional actions. Once there are mechanisms such as mutation and environmental influences that maintain variation within populations, whether cooperation evolves may depend on the variation in the cooperativeness trait. Variation means that it may be worth taking a chance that a partner is cooperative by being cooperative. When there are markets, so that individuals can break off interactions to seek a better partner, variation promotes choosiness and hence penalizes those uncooperative individuals, who are rejected. Variation promotes the need to monitor the previous behaviour of others, and once this social sensitivity exists, the need to maintain a good reputation can promote cooperation.     

Analysis of tumour-immune evasion with chemo-immuno therapeutic treatment with quadratic optimal control

A simple mathematical model for the growth of tumour with discrete time delay in the immune system is considered. The dynamical behaviour of our system by analysing the existence and stability of our system at various equilibria is discussed elaborately. We set up an optimal control problem relative to the model so as to minimize the number of tumour cells and the chemo-immunotherapeutic drug administration. Sensitivity analysis of tumour model reveals that parameter value has a major impact on the model dynamics. We numerically illustrate how does these delay can change the stability region of the immune-control equilibrium and display the different impacts to the control of tumour. Finally, epidemiological implications of our analytical findings are addressed critically.     

Comparison of DAS-ELISA and qRT-PCR for the detection of cucurbit viruses in seeds

The importance of seeds as virus vehicles for long-distance dissemination makes essential the availability of adequate methods of analysis to guarantee the quality of seed lots. To improve the repertoire of sensitive methods for seed diagnosis, we have developed quantitative real-time RT-PCR assays (RT-qPCR) based on the TaqMan technology to detect three viruses which are seed transmitted in cucurbits, namely, cucumber green mottle mosaic virus (CGMMV), squash mosaic virus (SqMV) and melon necrotic spot virus (MNSV), and compared these assays with DAS-ELISA, the main method used for virus detection in seeds. The estimated RT-qPCR limits of detection were 96, 97 and 740 RNA target molecules for CGMMV, SqMV and MNSV, respectively. The estimated RT-qPCR analytical sensitivity (highest dilution capable of generating a detectable amplification signal) ranged between 10 and 1 pg/μL for the three viruses. Using RT-qPCR, we could reliably detect a single SqMV- or CGMMV-contaminated seed among 999 uncontaminated seeds in a seed lot, and sensitivities were 1,000 and 10,000 times of those provided by DAS-ELISA for SqMV and CGMMV, respectively. Our RT-qPCR assays have proved to be highly suitable for the analysis of seed lots, and the possibility of their implementation into certification programme should be taken into consideration.     

Structural and functional neuroprotection in glaucoma: role of galantamine-mediated activation of muscarinic acetylcholine receptors

Glaucoma is the leading cause of irreversible blindness worldwide. Loss of vision due to glaucoma is caused by the selective death of retinal ganglion cells (RGCs). Treatments for glaucoma, limited to drugs or surgery to lower intraocular pressure (IOP), are insufficient. Therefore, a pressing medical need exists for more effective therapies to prevent vision loss in glaucoma patients. In this in vivo study, we demonstrate that systemic administration of galantamine, an acetylcholinesterase inhibitor, promotes protection of RGC soma and axons in a rat glaucoma model. Functional deficits caused by high IOP, assessed by recording visual evoked potentials from the superior colliculus, were improved by galantamine. These effects were not related to a reduction in IOP because galantamine did not change the pressure in glaucomatous eyes and it promoted neuronal survival after optic nerve axotomy, a pressure-independent model of RGC death. Importantly, we demonstrate that galantamine-induced ganglion cell survival occurred by activation of types M1 and M4 muscarinic acetylcholine receptors, while nicotinic receptors were not involved. These data provide the first evidence of the clinical potential of galantamine as neuroprotectant for glaucoma and other optic neuropathies, and identify muscarinic receptors as potential therapeutic targets for preventing vision loss in these blinding diseases.