Constructing a Sophistication Index as a Method of Market Segmentation of Commercial Farming Businesses in South Africa

This study investigates the process of index construction as a means of measuring a hypothetical construct that can typically not be measured by a single question or item and applying it as a method of market segmentation. The availability of incidental secondary data provided a relevant quantitative basis to illustrate this process by constructing a commercial farming sophistication index for South Africa. It was evident that this approach offers an appropriate and useful means of segmenting a market. Several factors contribute to the appeal of this approach. Among others, it addresses important priorities in the area of future segmentation research. By offering classification rules based on characteristics that can easily be observed or elicited through asking a few key questions, new or potential buyers can be grouped by buying behaviour segment. Furthermore, the multi-step process that was employed provides a systematic and structured multivariate approach to segmentation. It also facilitates replication of the process when conducting future studies. Lastly, the outcome of this type of segmentation method offers researchers and marketing practitioners a procedure, in the form of an equation, to calculate index scores and provide rules to segment the market based on predefined intervals. Hence, the challenge to replicate segment formation across independent future studies is addressed.Keywords: Agribusiness, Commercial Farming, Index Construction, Segmentation, Sophisticatio

Conceptual Frameworks and Methods for Advancing Invasion Ecology

Invasion ecology has much advanced since its early beginnings. Nevertheless, explanation, prediction, and management of biological invasions remain difficult. We argue that progress in invasion research can be accelerated by, first, pointing out difficulties this field is currently facing and, second, looking for measures to overcome them. We see basic and applied research in invasion ecology confronted with difficulties arising from (A) societal issues, e.g., disparate perceptions of invasive species; (B) the peculiarity of the invasion process, e.g., its complexity and context dependency; and (C) the scientific methodology, e.g., imprecise hypotheses. To overcome these difficulties, we propose three key measures: (1) a checklist for definitions to encourage explicit definitions; (2) implementation of a hierarchy of hypotheses (HoH), where general hypotheses branch into specific and precisely testable hypotheses; and (3) platforms for improved communication. These measures may significantly increase conceptual clarity and enhance communication, thus advancing invasion ecology

Thermal Perceptual Thresholds are typical in Autism Spectrum Disorder but Strongly Related to Intra-individual Response Variability

Individuals with autism spectrum disorder (ASD) are often reported to exhibit an apparent indifference to pain or temperature. Leading models suggest that this behavior is the result of elevated perceptual thresholds for thermal stimuli, but data to support these assertions are inconclusive. An alternative proposal suggests that the sensory features of ASD arise from increased intra-individual perceptual variability. In this study, we measured method-of-limits warm and cool detection thresholds in 142 individuals (83 with ASD, 59 with typical development [TD], aged 7–54 years), testing relationships with diagnostic group, demographics, and clinical measures. We also investigated the relationship between detection thresholds and a novel measure of intra-individual (trial-to-trial) threshold variability, a putative index of “perceptual noise.” This investigation found no differences in thermal detection thresholds between individuals with ASD and typical controls, despite large differences between groups in sensory reactivity questionnaires and modest group differences in intra-individual variability. Lower performance IQ, male sex, and higher intra-individual variability in threshold estimates were the most significant predictors of elevated detection thresholds. Although no psychophysical measure was significantly correlated with questionnaire measures of sensory hyporeactivity, large intra-individual variability may partially explain the elevated psychophysical thresholds seen in a subset of the ASD population

Constructing a sophistication index as a method of market segmentation of commercial farming businesses in South Africa

This study investigates the process of index construction as a means of measuring a hypothetical construct that can typically not be measured by a single question or item and applying it as a method of market segmentation. The availability of incidental secondary data provided a relevant quantitative basis to illustrate this process by constructing a commercial farming sophistication index for South Africa. It was evident that this approach offers an appropriate and useful means of segmenting a market. Several factors contribute to the appeal of this approach. Among others, it addresses important priorities in the area of future segmentation research. By offering classification rules based on characteristics that can easily be observed or elicited through asking a few key questions, new or potential buyers can be grouped by buying behaviour segment. Furthermore, the multi-step process that was employed provides a systematic and structured multivariate approach to segmentation. It also facilitates replication of the process when conducting future studies. Lastly, the outcome of this type of segmentation method offers researchers and marketing practitioners a procedure, in the form of an equation, to calculate index scores and provide rules to segment the market based on predefined intervals. Hence, the challenge to replicate segment formation across independent future studies is addressed

A Eukaryotic Sensor for Membrane Lipid Saturation

Maintaining a fluid bilayer is essential for cell signaling and survival. Lipid saturation is a key factor determining lipid packing and membrane fluidity, and it must be tightly controlled to guarantee organelle function and identity. A dedicated eukaryotic mechanism of lipid saturation sensing, however, remains elusive. Here we show that Mga2, a transcription factor conserved among fungi, acts as a lipid-packing sensor in the ER membrane to control the production of unsaturated fatty acids. Systematic mutagenesis, molecular dynamics simulations, and electron paramagnetic resonance spectroscopy identify a pivotal role of the oligomeric transmembrane helix (TMH) of Mga2 for intra-membrane sensing, and they show that the lipid environment controls the proteolytic activation of Mga2 by stabilizing alternative rotational orientations of the TMH region. This work establishes a eukaryotic strategy of lipid saturation sensing that differs significantly from the analogous bacterial mechanism relying on hydrophobic thicknes