Deterministic processes vary during community assembly for ecologically dissimilar taxa

The continuum hypothesis states that both deterministic and stochastic processes contribute to the assembly of ecological communities. However, the contextual dependency of these processes remains an open question that imposes strong limitations on predictions of community responses to environmental change. Here we measure community and habitat turnover across multiple vertical soil horizons at 183 sites across Scotland for bacteria and fungi, both dominant and functionally vital components of all soils but which differ substantially in their growth habit and dispersal capability. We find that habitat turnover is the primary driver of bacterial community turnover in general, although its importance decreases with increasing isolation and disturbance. Fungal communities, however, exhibit a highly stochastic assembly process, both neutral and non-neutral in nature, largely independent of disturbance. These findings suggest that increased focus on dispersal limitation and biotic interactions are necessary to manage and conserve the key ecosystem services provided by these assemblages

Electronically-Controllable Floating Inductor using OMA with Enhanced Input Dynamic Range

Abstract Recently a new formulation for realizing a floating inductance (FI) using an OMA, which takes into account the dominant pole of the op-amp employed in the OMA, without requiring any external capacitor was proposed. The proposition, however, suffered from a limited inputdynamic-range of operation owing to limited open-loop signal handling capability of the op-amp used. In this paper we propose an improved FI formulation with increased input signal handling capability. The electronically controllable floating inductance feature of the resulting circuit has been shown by replacing all the building blocks of the FI formulation by their CMOS counterparts. The workability of the proposed FI has been demonstrated by PSPICE simulations

Current-Mode Universal Biquad Using Current Followers: A Minimal Realization

A new universal biquad filter is presented which employs a minimum number of active elements (only three current followers (CF)) along with a minimum number of passive components (i.e. only two resistors and two capacitors). The new circuit provides all the five standard filter responses (namely lowpass, bandpass, highpass, notch and allpass) from the same structure without requiring any component matching conditions and with explicit current outputs available from high output impedance terminals. The workability of the proposed universal biquad, realised with unity-gain current followers implemented in 0.35 µm CMOS and operated from 1.65 volts DC power supplies, is established by SPICE simulations