Visual Cues Given by Humans Are Not Sufficient for Asian Elephants (Elephas maximus) to Find Hidden Food

Recent research suggests that domesticated species – due to artificial selection by humans for specific, preferred behavioral traits – are better than wild animals at responding to visual cues given by humans about the location of hidden food. \Although this seems to be supported by studies on a range of domesticated (including dogs, goats and horses) and wild (including wolves and chimpanzees) animals, there is also evidence that exposure to humans positively influences the ability of both wild and domesticated animals to follow these same cues. Here, we test the performance of Asian elephants (Elephas maximus) on an object choice task that provides them with visual-only cues given by humans about the location of hidden food. Captive elephants are interesting candidates for investigating how both domestication and human exposure may impact cue-following as they represent a non-domesticated species with almost constant human interaction. As a group, the elephants (n = 7) in our study were unable to follow pointing, body orientation or a combination of both as honest signals of food location. They were, however, able to follow vocal commands with which they were already familiar in a novel context, suggesting the elephants are able to follow cues if they are sufficiently salient. Although the elephants’ inability to follow the visual cues provides partial support for the domestication hypothesis, an alternative explanation is that elephants may rely more heavily on other sensory modalities, specifically olfaction and audition. Further research will be needed to rule out this alternative explanation.     

Detection of Antibody against Fungal Glucosylceramide in Immunocompromised Patients: A Potential New Diagnostic Approach for Cryptococcosis

We have developed an ELISA to determine the value of anti-glucosylceramide antibody for the prediction of disseminated cryptococcosis in immunocompromised subjects and performed a clinical prospective study at the Medical University of South Carolina. The study enrolled a total of 53 patients who were free of active fungal diseases at the time of enrollment but at risk of developing one because they were all immunocompromised, e.g., (1) patients positive for HIV and (2) patients post- or awaiting solid organ transplantation. Among 53 patients enrolled, two patients developed invasive cryptococcosis, and in both patients, IgM anti-GlcCer was detected in sera using the ELISA at least 6 weeks prior to the clinical presentation of the brain disease. These results were corroborated by a cryptococcal antigen lateral flow assay, which was also positive in serum prior to the development of meningoencephalitis. However, a high number of positive results were also detected in patients with no evidence of cryptococcosis. This study highlights the potential utility of this new assay in early diagnostic testing algorithms for patients at risk for cryptococcosis, but further investigations are needed to validate the sensitivity and specificity of the glucosylceramide ELISA as a predictor of cryptococcosis.     

Activation of knot (kn) specifies the 3-4 intervein region in the Drosophila wing

Hedgehog (Hh) plays an important role in Drosophila wing patterning by inducing expression of Dpp, which serves to organize the wing globally across the A-P axis. We show here how Hh signalling also plays a direct role in patterning the medial wing through the activation of the Hh-target gene, knot (kn). kn is expressed in Hh-responsive cells near the A-P compartment boundary, where its expression is dependent on fu, a component of Hh signalling. kn is required for the proper positioning of veins 3 and 4 and to prevent ectopic venation between them. Furthermore, the expansion anteriorly of the normal kn expression domain causes an associated anterior shift in the position of vein 3 in the resultant wing. Ectopic expression of kn elsewhere in the wing imaginal disc results in the failure to properly activate the vein initiation genes, rho and Dl. Expression of the gene encoding the EGF-receptor (EGFR), which is required for vein initiation and subsequent differentiation, is normally depressed in the 3-4 intervein region. This downregulation of EGFR in the medial portion of the imaginal disc is dependent on kn activity and ectopic expression of kn inactivates EGFR elsewhere in the wing primordium. We propose kn expression in Hh-responsive cells of the wing blade anlagen during the late third instar creates a zone of cells in the medial wing in which vein primordia cannot be induced. The primordia for veins 3 and 4 are laid down adjacent to the kn-imposed vein-free zone, presumably by a signalling factor (such as Vn) also synthesized in the medial region of the wing.