Threshold of anthropogenic sound levels within protected landscapes in Kerala, India, for avian habitat quality and conservation.

Anthrophony is an important determinant of habitat quality in the Anthropocene. Acoustic adaptation of birds at lower levels of anthrophony is known. However, threshold anthrophony, beyond which biophony starts decreasing, is less explored. Here, we present empirical results of the relationship between anthrophony and biophony in four terrestrial soundscapes. The constancy of the predicted threshold vector normalised anthropogenic power spectral density (~ 0.40 Watts/Hz) at all the study sites is intriguing. We propose the threshold value of anthropogenic power spectral density as an indicator of the avian acoustic tolerance level in the study sites. The findings pave the way to determine permissible sound levels within protected landscapes and directly contribute to conservation planning.

Geometric entropy of plant leaves: A measure of morphological complexity.

Shape is an objective characteristic of an object. A boundary separates a physical object from its surroundings. It defines the shape and regulates energy flux into and from an object. Visual perception of a definite shape (geometry) of physical objects is an abstraction. While the perceived geometry at an object's sharp interface (macro) creates a Euclidian illusion of actual shape, the notion of diffuse interfaces (micro) allows an understanding of the realistic form of objects. Here, we formulate a dimensionless geometric entropy of plant leaves (SL) by a 2-D description of a phase-field function. We applied this method to 112 tropical plant leaf images. SL was estimated from the leaf perimeter (P) and leaf area (A). It correlates positively with a fractal dimensional measure of leaf complexity, viz., segmental fractal complexity. Leaves with a higher P: A ratio have higher SL and possess complex morphology. The univariate cluster analysis of SL reveals the taxonomic relationship among the leaf shapes at the genus level. An increase in SL of plant leaves could be an evolutionary strategy. The results of morphological complexity presented in this paper will trigger discussion on the causal links between leaf adaptive stability/efficiency and complexity. We present SL as a derived plant trait to describe plant leaf complexity and adaptive stability. Integrating SL into other leaf physiological measures will help to understand the dynamics of energy flow between plants and their environment.

Menkes kinky hair syndrome: a rare neurodegenerative disease.

Menkes kinky hair disease is a rare X-linked recessive disease nearly exclusively affecting males who present at 2-3 months of age due to abnormal functioning of copper-dependent enzymes due to deficiency of copper. Here, we describe a completely worked-up case of a 4-month-old male infant with very typical history and radiological features confirmed by biochemical and trichoanalysis. The initially seen asymmetric cortical and subcortical T2 hyperintensities in cerebral and cerebellar hemispheres converted into symmetrical diffuse cerebral and predominantly cerebellar atrophy with uniform loss of both white and grey matter on follow-up MRI. Also, subdural hemorrhages of various sizes and different stages and tortuosity of larger proximal intracranial vessels with distal narrowing were identified. Ours is a completely worked-up proven case of Menkes kinky hair disease (MKHD) with history, electroencephalography, biochemical, trichoanalysis, and MRI findings. This is a good teaching case and shows importance of clinical examination and biochemistry as complimentary to MRI. Tortuous intracranial arteries with blocked major vessels are found only in this disease, thus stressing the value of MR Angiography in these patients.