Allozyme Electrophoretic Methods for Analysing Genetic Variation in Giant Clams (Tridacnidae)

Resource /Energy Economics and Policy,

Effect of Organic Turmeric (Curcuma longa) Feeding on Testicular Histology of Rabbits Exposed to Ultraviolet Radiation

A total of thirty six male rabbits ranging in weight between 450-600g were weight-balanced into six treatment groups that received rabbit diets either without turmeric (D1) or with turmeric (D2) at varying periods within a nine- week experimental period. The treatments were T0, T1, T2, T3, T4 and T5 for control, D2 plus exposure to UV radiation, D2 until radiation, D2 after radiation, D1 throughout the experimental period with UV radiation and D2 throughout the experimental period without UV radiation, respectively. Testicular histology revealed that feeding organic turmeric in the diet before exposure conferred some protection on the testicular tissue while the feeding of turmeric in the diet after exposure corrected the damage inflicted by exposure to UV radiation. The group (T4) that did not receive turmeric showed conspicuous damage in the testicular tissue on exposure to ultraviolet radiation. It was concluded that organic turmeric could alleviate the histological damage on account of exposure to ultraviolet radiation. Key words: Organic turmeric, Ultraviolet radiation, Rabbit, Testis, Histolog

Critical properties of loop percolation models with optimization constraints

We study loop percolation models in two and in three space dimensions, in which configurations of occupied bonds are forced to form closed loop. We show that the uncorrelated occupation of elementary plaquettes of the square and the simple cubic lattice by elementary loops leads to a percolation transition that is in the same universality class as the conventional bond percolation. In contrast to this an optimization constraint for the loop configurations, which then have to minimize a particular generic energy function, leads to a percolation transition that constitutes a new universality class, for which we report the critical exponents. Implication for the physics of solid-on-solid and vortex glass models are discussed.Comment: 8 pages, 8 figure

Urological cancer patients receiving treatment during COVID-19 : a single-centre perspective

Background Active cancer, immunosuppressive treatments and immunotherapies have been reported to increase cancer patients’ risk of developing severe COVID-19 infection. For patients and clinicians, treatment risk must be weighed against disease progression. Methods This retrospective case series surveys urological cancer patients who made informed decisions to continue anticancer treatment (ACT) at one centre from March to June 2020. Results Sixty-one patients (44 bladder, 10 prostate, 7 upper urinary tract cancers) received 195 cycles of ACT (99 chemotherapy, 59 immunotherapy, 37 as part of ongoing clinical trials), with a range of indications: 43 palliative, 10 neoadjuvant, 8 adjuvant. One patient tested positive for COVID-19 but experienced only mild symptoms. Fourteen patients interrupted treatment outside of their schedule, seven of these due to potential COVID-19 associated risk. ACT supportive steroids were not associated with higher rates of COVID-19. Conclusions This single-centre series reports that ACT administration did not result in an apparent excess in symptomatic COVID-19 infections

Cats, connectivity and conservation: incorporating datasets and integrating scales for wildlife management

Understanding resource selection and quantifying habitat connectivity are fundamental to conservation planning for both land-use and species management plans. However, datasets available to management authorities for resource selection and connectivity analyses are often highly limited and fragmentary. As a result, measuring connectivity is challenging, and often poorly integrated within conservation planning and wildlife management. To exacerbate the challenge, scale-dependent resource use makes inference across scales problematic, resource use is often modelled in areas where the species is not present, and connectivity is typically measured using a source-to-sink approach, erroneously assuming animals possess predefined destinations. Here, we used a large carnivore, the leopard Panthera pardus, to characterise resource use and landscape connectivity across a vast, biodiverse region of southern Africa. Using a range of datasets to counter data deficiencies inherent in carnivore management, we overcame methodological limitations by employing occupancy modelling and resource selection functions across three orders of selection, and estimated landscape-scale habitat connectivity – independent of a priori source and sink locations – using circuit theory. We evaluated whether occupancy modelling on its own was capable of accurately informing habitat connectivity, and identified conservation priorities necessary for applied management. We detected markedly different scale-dependent relationships across all selection orders. Our multi-data, multi-scale approach accurately predicted resource use across multiple scales and demonstrates how management authorities can more suitably utilise fragmentary datasets. We further developed an unbiased landscape-scale depiction of habitat connectivity, and identified key linkages in need of targeted management. We did not find support for the use of occupancy modelling as a proxy for landscape-scale habitat connectivity and further caution its use within a management context. Synthesis and applications. Maintaining habitat connectivity remains a fundamental component of wildlife management and conservation, yet data to inform these biological and ecological processes are often scarce. We present a robust approach that incorporates multi-scale fragmentary datasets (e.g. mortality data, permit data, sightings data), routinely collected by management authorities, to inform wildlife management and land-use planning. We recommend that management authorities employ a multi-data, multi-scale connectivity approach—as we present here—to identify management units at risk of low connectivity

Carbon Nanotubes as Nanoelectromechanical Systems

We theoretically study the interplay between electrical and mechanical properties of suspended, doubly clamped carbon nanotubes in which charging effects dominate. In this geometry, the capacitance between the nanotube and the gate(s) depends on the distance between them. This dependence modifies the usual Coulomb models and we show that it needs to be incorporated to capture the physics of the problem correctly. We find that the tube position changes in discrete steps every time an electron tunnels onto it. Edges of Coulomb diamonds acquire a (small) curvature. We also show that bistability in the tube position occurs and that tunneling of an electron onto the tube drastically modifies the quantized eigenmodes of the tube. Experimental verification of these predictions is possible in suspended tubes of sub-micron length.Comment: 8 pages, 5 eps figures included. Major changes; new material adde

Convergent evolution of floral signals underlies the success of Neotropical orchids

The great majority of plant species in the tropics require animals to achieve pollination, but the exact role of floral signals in attraction of animal pollinators is often debated. Many plants provide a floral reward to attract a guild of pollinators, and it has been proposed that floral signals of non-rewarding species may converge on those of rewarding species to exploit the relationship of the latter with their pollinators. In the orchid family (Orchidaceae), pollination is almost universally animal-mediated, but a third of species provide no floral reward, which suggests that deceptive pollination mechanisms are prevalent. Here, we examine floral colour and shape convergence in Neotropical plant communities, focusing on certain food-deceptive Oncidiinae orchids (e.g. Trichocentrum ascendens and Oncidium nebulosum) and rewarding species of Malpighiaceae. We show that the species from these two distantly related families are often more similar in floral colour and shape than expected by chance and propose that a system of multifarious floral mimicry—a form of Batesian mimicry that involves multiple models and is more complex than a simple one model–one mimic system—operates in these orchids. The same mimetic pollination system has evolved at least 14 times within the species-rich Oncidiinae throughout the Neotropics. These results help explain the extraordinary diversification of Neotropical orchids and highlight the complexity of plant–animal interactions