Structure of the species-energy relationship

The relationship between energy availability and species richness (the species-energy relationship) is one of the best documented macroecological phenomena. However, the structure of species distribution along the gradient, the proximate driver of the relationship, is poorly known. Here, using data on the distribution of birds in southern Africa, for which species richness increases linearly with energy availability, we provide an explicit determination of this structure. We show that most species exhibit increasing occupancy towards more productive regions (occurring in more grid cells within a productivity class). However, average reporting rates per species within occupied grid cells, a correlate of local density, do not show a similar increase. The mean range of used energy levels and the mean geographical range size of species in southern Africa decreases along the energy gradient, as most species are present at high productivity levels but only some can extend their ranges towards lower levels. Species turnover among grid cells consequently decreases towards high energy levels. In summary, these patterns support the hypothesis that higher productivity leads to more species by increasing the probability of occurrence of resources that enable the persistence of viable populations, without necessarily affecting local population densities

Differences in soundscape appreciation of walking sounds from different footpath materials in urban parks

The perception of the acoustic environment, namely the soundscape, in urban parks has attracted increasing attention. There is a growing belief that the management of the acoustic environment of urban parks should be addressed within a broader soundscape methodology rather than a merely noise control one. One of the most frequent sound sources in urban parks is walking sound; however walking sound perception so far has mainly been investigated for indoor environments. This paper aims to investigate the overall effect of walking sounds from different walked-on materials on people's soundscape, combined with other non-acoustical factors. Moreover, this research investigates how perception varies when the walking sound is self-produced or simply listened. To this purpose, two laboratory experiments in Italy and UK were carried out with four walked-on materials that were considered to be possible design solutions for the footpaths of urban parks: grass, wood, stone and gravel. Results showed a significant effect of materials on perceived noise annoyance and soundscape quality, as well as a partial influence of other nonacoustical factor. Considering the individual responses for the four selected materials, gravel was associated to the worst soundscape quality (M = 38.42) while grass to the best one (M = 65.05). While a group effect (Italian and UK samples) was observed for perceived noise annoyance corresponding to the materials, no significant group effect was found for soundscape evaluation. Eventually, people simply listening to the walking sounds resulted to be less tolerant towards them, with respect to people who self-produced the sounds by walking

Antecedents of trust among buyer and seller within the South African automotive supply chains

Background: Positive supplier relationships result in trust and eventually sustainability. However, the opposite seems to be true in the South African automotive supply chain relationships that are characterised by conflict. Literature states that in the absence of trust, sustainability is compromised. The problem pertains to the erosion of trust because of conflict between suppliers in the South African automotive supply chains. Objectives: The main purpose of the research was to address the question: What are the antecedents of trust between buyer and seller within the South African automotive supply chains? The primary objective was to determine the value-adding antecedents of trust followed by presenting the antecedent with the strongest correlation towards trust. Method: The study was explanatory and descriptive by nature to determine relationships between constructs. The empirical research utilised a quantitative census, thus targeting all senior managers representing Tier 1 automotive component suppliers. A deductive approach through a structured close-ended questionnaire tested the managers’ perception on trust. The response rate was 81.4% with 144 participants. After factor analysis, a path analysis was compiled, depicting the antecedents of trust. Results: The study found that antecedents showing the strongest correlation with trust were the core offering, inclusive of product delivery and quality followed by personal interaction that forms part of the sourcing process. Conclusion: The research study makes a theoretical contribution by presenting a conceptual structure on trust by depicting its antecedents. Managerial contributions include recommendations on how to enhance trust through a relational governance strategy

Self-rated health implications of noise for open-plan office workers: An overview of the literature

In open-plan offices (OPO), workspaces without ground-to-ceiling dividers, noise is one of the most complained about aspects, causing physical and psychological impacts. With the increasing interest for a human-centric design, notably after the publication of ISO 22955, this review aims to identify the main noise sources in this office layout and the employees’ perception of related health effects, evaluating the interventions proposed to overcome their impacts. Following the PRISMA guidelines, a review was conducted using the Scopus and PubMed databases, considering subjective questionnaires distributed in offices, which could include physical workspace assessment. It excluded studies limited to: (a) laboratory experiments; (b) isolated cognitive tests; (c) office layouts other than OPO; (d) systematic reviews; and (e) mathematical models. Sixty studies were identified and the screening process resulted in 11 selected for inclusion, which indicated irrelevant speech, chatting, and telephone ringing as the main noise sources causing productivity loss, stress, and low comfort rates due to distraction and lack of privacy. To overcome these impacts, researchers suggested the use of sound-absorbing surfaces, separated zones for different tasks and headphones, although their effectiveness relies on human behaviour and economic feasibility. Thus, the evidence indicates that noise is a recurrent issue in OPOs, it demonstrates the importance of appropriate acoustic performance of the workspace and the necessity of new studies regarding OPO workers’ perception of noise and their health, particularly after the COVID-19 new safety guidelines

Assessment methods and factors determining positive indoor soundscapes in residential buildings: A systematic review

The design of an indoor acoustic environment positively perceived by building occupants requires a perceptual approach to be adopted in order to define what makes it sound good. Soundscape standards ISO 12913 have been introduced to assess how the acoustic environment is perceived, in context, by people. According to the standards, a straightforward characterization of a soundscape as positive is currently possible only through measurements by persons, because of a current gap in linking perceptual metrics to acoustic or psychoacoustic measurements. In addition, despite applying also to indoor contexts, methods and perceptual metrics described by the standards have been mainly derived from studies related to outdoor urban environments and it is not clear whether they could be directly applied indoor. For this reason, a systematic review was performed to investigate: (i) Data collection methods used in the literature for indoor residential soundscapes and (ii) factors, output of such methods, that characterize them positively. For this purpose, a systematic review has been conducted in accordance with the PRISMA guidelines (preferred reporting items for systematic reviews and meta-analyses) guidelines. The Scopus database was searched for peer-reviewed journal papers published in English, between 1 January 2009 and 24 June 2019, including: (1) field or laboratory studies relevant to residential buildings and (2) studies assessing factors that influence the perception by building users of indoor acoustic environments. The search excluded studies related to: (a) Speech perception issues; (b) noise-induced sleep disturbance; (c) acoustic perception by hearing impaired building users; (d) perception of vibrations or impact sounds. The search returned 1087 results. After the screening process, 37 articles were finally included. Given the differences in methodologic approaches, a quantitative meta-analysis could not be performed, and a qualitative approach was adopted instead. A large part of the selected literature reflected a general effort of minimizing noise annoyance by reducing noise exposure and, in particular, noise levels. Questionnaires and guided interviews were used to capture people's perception, while the adoption of soundwalks and non-participatory behavioral studies did not emerge in the review literature and need further investigation. The evaluation of a variety of auditory sensations both in their positive and negative dimensions, beyond annoyance, would be required to explore the positive perceptual potential of sounds. Besides sound level, a variety of factors related and unrelated to the acoustic environment were found to affect perceptual outcomes and a framework of evaluation has been proposed as a reference for future assessments. Results encourage the integration of soundscape methodologies into IEQ research, in order to enhance user health and well-being

Resilience trinity: safeguarding ecosystem functioning and services across three different time horizons and decision contexts

Ensuring ecosystem resilience is an intuitive approach to safeguard the functioning of ecosystems and hence the future provisioning of ecosystem services (ES). However, resilience is a multi‐faceted concept that is difficult to operationalize. Focusing on resilience mechanisms, such as diversity, network architectures or adaptive capacity, has recently been suggested as means to operationalize resilience. Still, the focus on mechanisms is not specific enough. We suggest a conceptual framework, resilience trinity, to facilitate management based on resilience mechanisms in three distinctive decision contexts and time‐horizons: 1) reactive, when there is an imminent threat to ES resilience and a high pressure to act, 2) adjustive, when the threat is known in general but there is still time to adapt management and 3) provident, when time horizons are very long and the nature of the threats is uncertain, leading to a low willingness to act. Resilience has different interpretations and implications at these different time horizons, which also prevail in different disciplines. Social ecology, ecology and engineering are often implicitly focussing on provident, adjustive or reactive resilience, respectively, but these different notions of resilience and their corresponding social, ecological and economic tradeoffs need to be reconciled. Otherwise, we keep risking unintended consequences of reactive actions, or shying away from provident action because of uncertainties that cannot be reduced. The suggested trinity of time horizons and their decision contexts could help ensuring that longer‐term management actions are not missed while urgent threats to ES are given priority

A Psychoacoustic Investigation on the Effect of External Shading Devices on Building Facades

Due to energetic and natural lighting factors, building facades often present external shading devices, but the acoustic properties of such devices have not yet been well studied. This study was carried out using a full-scale model of a portion of a shading device, in a semi-anechoic chamber, using traditional and sound absorbing louvres. The psychoacoustic effects produced by the shading system were evaluated through comparisons between averaged values of loudness, roughness and sharpness levels, as well as sound pressure levels as reference. Results highlighted that the sound absorbing shading device offers good attenuation in terms of loudness, roughness and sound pressure level, with a small reduction in sharpness. The traditional shading system studied does not efficiently reduce the analysed parameters, or even worsens the situation. Several analyses of variance were carried out, one for each situation studied. The sound source position and the louvres’ tilt angle both produce statistically significant effects on almost all of the variations of the parameters studied. The analyses of the partial eta squared factors highlighted that source position and louvre tilt angle affect the variations of the parameters studied to a different degree in respect of the two types of louvres

Acoustic Design Criteria in Naturally Ventilated Residential Buildings: New Research Perspectives by Applying the Indoor Soundscape Approach

The indoor-outdoor connection provided by ventilation openings has been so far a limiting factor in the use of natural ventilation (NV), due to the apparent conflict between ventilation needs and the intrusion of external noise. This limiting factor impedes naturally ventilated buildings meeting the acoustic criteria set by standards and rating protocols, which are reviewed in this paper for residential buildings. The criteria reflect a general effort to minimize noise annoyance by reducing indoor sound levels, typically without a distinction based on a ventilation strategy. Research has developed a number of solutions, discussed here, that try to guarantee ventilation without compromising façade noise insulation, but, currently, none have been adopted on a large scale. This concept paper highlights the main limits of the current approach. First, a fragmented view towards indoor environmental quality has not included consideration of the following acoustic criteria: (i) how buildings are designed and operated to meet multiple needs other than acoustical ones (e.g., ventilation, visual, and cooling needs) and (ii) how people respond to multiple simultaneous environmental factors. Secondly, the lack of a perceptual perspective has led acoustic criteria to neglect the multiple cognitive and behavioral factors impinging on comfort in naturally ventilated houses. Indeed, factors such as the connection with the outside and the sense of control over one’s environment may induce “adaptive acoustic comfort” opportunities that are worth investigating. The mere use of different sound level limits would not be enough to define criteria tailored to the complex user–building interaction that occurs under NV conditions. More holistic and human-centered approaches are required to guarantee not only neutrally but even positively perceived indoor acoustic environments. For this reason, this paper considers this apparent conflict from a soundscape viewpoint, in order to expose still unexplored lines of research. By underpinning a perceptual perspective and by contextualizing it, the indoor soundscape approach provides a framework capable of overcoming the limits of the traditional noise control approach. This could provide the opportunity to foster a wider adoption of NV as a passive design strategy that enhances user health and well-being, while enabling low-cost, and low-energy cooling and ventilation, thereby contributing to current climate change challenge

Relationship value antecedents in the South African automotive component supply chain

Orientation: Although literature agrees on the importance of ‘relationship value’, the term is still seen as ambiguous and authors fail to agree on its antecedents. Within a challenging global arena, relationship value is believed to result in business retention. It is therefore critical to have a better understanding of this value to ensure business sustainability within supply chains. Literature suggests that relationship value drivers comprise three dimensions, namely a core offering, sourcing process and customer operations. Research purpose: The contribution of the research reported on in this paper is an enhanced conceptual understanding of relationship value and its salient drivers within the South African automotive supply chains. Motivation for the study: Literature invites more research on relationship value and its drivers. Therefore, the research reported on tested the antecedents of relationship value. Research design, approach and method: Relationship value drivers were tested through empirical research within the South African automotive supply chains by means of a path analysis. The research utilised a closed-ended questionnaire, and targeted managers among Tier 1 buyers and asked them about the relationship value traits of their best Tier 2 suppliers. Main findings: It was found that personal interaction, which forms part of the sourcing process, is viewed as the strongest antecedent of relationship value within the South African automotive supply chains, followed by product quality and delivery. Practical/managerial implications: It is suggested that superior supply chain practices within the South African automotive industry might secure business retention. Automotive component suppliers are therefore advised to implement relationship value strategies to promote higher value through personal interaction

Associations between indoor soundscapes, building services and window opening behaviour during the COVID-19 lockdown

Results of an online survey conducted during the COVID-19 lockdown among 848 home workers living in London (United Kingdom) and in Italy are reported with a focus on (1) the impacts of building services on the perception of the acoustic environment while working and relaxing at home and (2) the factors associated with window opening behaviour. The analyses showed no significant difference in soundscape appropriateness for relaxation depending on the heating, ventilation and cooling system typologies, and in soundscape appropriateness for working from home (WFH) based on the ventilation strategy. Higher soundscape appropriateness for WFH was associated with houses equipped only with radiant floors for heating in Italy and with air-cooling systems in London. In London, air systems resulted in higher perceived dominance of noise from building services compared to other systems. Overall, rooms with less dominant sounds from building services were evaluated as more appropriate for working and relaxing. The dominance of sky or buildings from the window view, outdoor noisiness, noise sensitivity, age and gender were not significantly associated with participants’ window opening behaviour while WFH. Differently, participants viewing more vegetation from windows in Italy were more likely (odds ratio: 1.279) to keep the window open while WFH