Self-generated morphology in lagoon reefs

10.7287/peerj.preprints.576 ◽

2015 ◽

Author(s):

David Blakeway ◽

Michael G Hamblin

Keyword(s):

Three Dimensional ◽

Coralline Algae ◽

Single Type ◽

External Control ◽

Reef Growth ◽

Ecological Process ◽

Substrate Topography ◽

Houtman Abrolhos Islands ◽

Ecological Mechanisms ◽

Reef Morphology

The three-dimensional form of a coral reef develops through interactions and feedbacks between its constituent organisms and their environment. Reef morphology therefore contains a potential wealth of ecological information, accessible if the relationships between morphology and ecology can be decoded. Traditionally, reef morphology has been attributed to external controls such as substrate topography or hydrodynamic influences. Little is known about inherent reef morphology in the absence of external control. Here we use reef growth simulations, based on observations in the cellular reefs of Western Australia’s Houtman Abrolhos Islands, to show that reef morphology is fundamentally determined by the mechanical behaviour of the reef-building organisms themselves—specifically their tendency to either remain in place or to collapse. Reef-building organisms that tend to remain in place, such as massive and encrusting corals or coralline algae, produce nodular reefs, whereas those that tend to collapse, such as branching Acropora, produce cellular reefs. The purest reef growth forms arise in sheltered lagoons dominated by a single type of reef builder, as in the branching Acropora-dominated lagoons of the Abrolhos. In these situations reef morphology can be considered a phenotype of the predominant reef building organism. The capacity to infer coral type from reef morphology can potentially be used to identify and map specific coral habitat in remotely sensed images. More generally, identifying ecological mechanisms underlying other examples of self-generated reef morphology can potentially improve our understanding of present-day reef ecology, because any ecological process capable of shaping a reef will almost invariably be an important process in real time on the living reef.

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Self-generated morphology in lagoon reefs

10.7287/peerj.preprints.576v1 ◽

2014 ◽

Author(s):

David Blakeway ◽

Michael G Hamblin

Keyword(s):

Coral Reefs ◽

Mechanical Behaviour ◽

Coralline Algae ◽

Single Type ◽

External Control ◽

Growth Forms ◽

Reef Growth ◽

Substrate Topography ◽

Houtman Abrolhos Islands ◽

Reef Morphology

The shapes and forms of coral reefs are generally attributed to external controls such as substrate topography or hydrodynamic influences. Little is known about inherent reef morphology in the absence of external control. Here we use reef growth simulations, based on observations in the cellular reefs of Western Australia’s Houtman Abrolhos Islands, to show that reef morphology is fundamentally determined by the mechanical behaviour of the reef-building organisms themselves—specifically their tendency to either remain in place or to collapse. A spectrum of realistic reef forms can be generated by varying a single parameter representing this characteristic. Reef-building organisms that tend to remain in place, such as massive and encrusting corals or coralline algae, produce nodular reefs, whereas those that tend to collapse, such as branching Acropora, produce cellular reefs. Inherent reef growth forms are best expressed in sheltered lagoons. The purest forms arise where a single type of reef builder prevails, as in the cellular reefs of the Abrolhos. In these cases reef morphology can be considered a phenotype of the predominant reef building organism.

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Self-generated morphology in lagoon reefs

10.7287/peerj.preprints.576v2 ◽

2014 ◽

Author(s):

David Blakeway ◽

Michael G Hamblin

Keyword(s):

Coral Reefs ◽

Mechanical Behaviour ◽

Coralline Algae ◽

Single Type ◽

External Control ◽

Growth Forms ◽

Reef Growth ◽

Substrate Topography ◽

Houtman Abrolhos Islands ◽

Reef Morphology

The shapes and forms of coral reefs are generally attributed to external controls such as substrate topography or hydrodynamic influences. Little is known about inherent reef morphology in the absence of external control. Here we use reef growth simulations, based on observations in the cellular reefs of Western Australia’s Houtman Abrolhos Islands, to show that reef morphology is fundamentally determined by the mechanical behaviour of the reef-building organisms themselves—specifically their tendency to either remain in place or to collapse. A spectrum of realistic reef forms can be generated by varying a single parameter representing this characteristic. Reef-building organisms that tend to remain in place, such as massive and encrusting corals or coralline algae, produce nodular reefs, whereas those that tend to collapse, such as branching Acropora, produce cellular reefs. Inherent reef growth forms are best expressed in sheltered lagoons. The purest forms arise where a single type of reef builder prevails, as in the cellular reefs of the Abrolhos. In these cases reef morphology can be considered a phenotype of the predominant reef building organism.

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Total Wrist Arthroplasty Alignment and Its Potential Association with Clinical Outcomes

Journal of Wrist Surgery ◽

10.1055/s-0041-1725172 ◽

2021 ◽

Author(s):

Bardiya Akhbari ◽

Kalpit N. Shah ◽

Amy M. Morton ◽

Janine Molino ◽

Douglas C. Moore ◽

...

Keyword(s):

Computed Tomography ◽

Clinical Outcomes ◽

Three Dimensional ◽

Radial Component ◽

Single Type ◽

Radiographic Images ◽

Computed Tomography Images ◽

Total Wrist Arthroplasty ◽

Flexion Extension ◽

Wrist Arthroplasty

Abstract Purpose There is a lack of quantitative research that describes the alignment and, more importantly, the effects of malalignment on total wrist arthroplasty (TWA). The main goal of this pilot study was to assess the alignment of TWA components in radiographic images and compare them with measures computed by three-dimensional analysis. Using these measures, we then determined if malalignment is associated with range of motion (ROM) or clinical outcomes (PRWHE, PROMIS, QuickDash, and grip strength). Methods Six osteoarthritic patients with a single type of TWA were recruited. Radiographic images, computed tomography images, and clinical outcomes of the wrists were recorded. Using posteroanterior and lateral radiographs, alignment measurements were defined for the radial and carpal components. Radiographic measurements were validated with models reconstructed from computed tomography images using Bland–Altman analysis. Biplanar videoradiography (<1mm and <1 degree accuracy) was used to capture and compute ROM of the TWA components. Linear regression assessed the associations between alignment and outcomes. Results Radiographic measures had a 95% limit-of-agreement (mean difference ± 1.96 × SD) of 3 degrees and 3mm with three-dimensional values, except for the measures of the carpal component in the lateral view. In our small cohort, wrist flexion–extension and radial–ulnar deviation were correlated with volar–dorsal tilt and volar–dorsal offset of the radial component and demonstrated a ROM increase of 3.7 and 1.6 degrees per degree increase in volar tilt, and 10.8 and 4.2 degrees per every millimeter increase in volar offset. The carpal component's higher volar tilt was also associated with improvements in patient-reported pain. Conclusions We determined metrics describing the alignment of TWA, and found the volar tilt and volar offset of the radial component could potentially influence the replaced wrist's ROM. Clinical Relevance TWA component alignment can be measured reliably in radiographs, and may be associated with clinical outcomes. Future studies must evaluate its role in a larger cohort.

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Effect of 3D printer enabled surface morphology and composition on coral growth in artificial reefs

Rapid Prototyping Journal ◽

10.1108/rpj-07-2020-0165 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Ilse Valenzuela Matus ◽

Jorge Lino Alves ◽

Joaquim Góis ◽

Augusto Barata da Rocha ◽

Rui Neto ◽

...

Keyword(s):

Additive Manufacturing ◽

Chemical Composition ◽

Chemical Elements ◽

Three Dimensional ◽

Coral Growth ◽

Coralline Algae ◽

Textured Surface ◽

Crustose Coralline Algae ◽

Statistical Parameters ◽

Content Type

Purpose The purpose of this paper is to prove and qualify the influence of textured surface substrates morphology and chemical composition on the growth and propagation of transplanted corals. Use additive manufacturing and silicone moulds for converting three-dimensional samples into limestone mortar with white Portland cement substrates for coral growth. Design/methodology/approach Tiles samples were designed and printed with different geometries and textures inspired by nature marine environment. Commercial coral frag tiles were analysed through scanning electron microscopy (SEM) to identify the main chemical elements. Raw materials and coral species were selected. New base substrates were manufactured and deployed into a closed-circuit aquarium to monitor the coral weekly evolution process and analyse the results obtained. Findings Experimental results provided positive statistical parameters for future implementation tests, concluding that the intensity of textured surface, interfered favourably in the coralline algae biofilm growth. The chemical composition and design of the substrates were determinant factors for successful coral propagation. Recesses and cavities mimic the natural rocks aspect and promoted the presence and interaction of other species that favour the richness of the ecosystem. Originality/value Additive manufacturing provided an innovative method of production for ecology restoration areas, allowing rapid prototyping of substrates with high complexity morphologies, a critical and fundamental attribute to guarantee coral growth and Crustose Coralline Algae. The result of this study showed the feasibility of this approach using three-dimensional printing technologies.

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Environmental justice and REDD+ safeguards in Laos: Lessons from an authoritarian political regime

AMBIO ◽

10.1007/s13280-021-01618-7 ◽

2021 ◽

Author(s):

Sabaheta Ramcilovic-Suominen ◽

Sophia Carodenuto ◽

Constance McDermott ◽

Juha Hiedanpää

Keyword(s):

Environmental Justice ◽

Minority Groups ◽

Three Dimensional ◽

Authoritarian Regime ◽

Political Regime ◽

External Control ◽

Climate Mitigation ◽

Political Debate ◽

Political Issues ◽

Marginalized Communities

AbstractBalancing agendas for climate mitigation and environmental justice continues to be one of the key challenges in climate change governance mechanisms, such as Reducing Emissions from Deforestation and Degradation (REDD+). In this paper we apply the three-dimensional environmental justice framework as a lens to examine the REDD+ process in the Lao People’s Democratic Republic (Laos) and the REDD+ social safeguards. We focus particularly on challenges to justice faced by marginalized communities living in forest frontier areas under an authoritarian regime. Drawing on policy analysis and open-ended interviews across different policy levels, we explore procedural, distributional, and recognitional justice across the REDD+ policy levels in Laos. We find that REDD+ social safeguards have been applied by both donors and state actors in ways that facilitate external control. We underscore how authoritarian regime control over civil society and ethnic minority groups thwarts justice. We also highlight how this political culture and lack of inclusiveness are used by donors and project managers to implement their projects with little political debate. Further obstacles to justice relate to limitations inherent in the REDD+ instrument, including tight schedules for dealing with highly sensitive socio-political issues under social safeguards. These findings echo other research but go further in questioning the adequacy of safeguards to promote justice under a nationally driven REDD+. We highlight the importance of recognition and political context, including aspects such as power relations, self-determination and self-governance of traditional or customary structures, in shaping justice outcomes.

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Associations between Benthic Cover and Habitat Complexity Metrics Obtained from 3D Reconstruction of Coral Reefs at Different Resolutions

Remote Sensing ◽

10.3390/rs12061011 ◽

2020 ◽

Vol 12 (6) ◽

pp. 1011 ◽

Cited By ~ 2

Author(s):

Atsuko Fukunaga ◽

John H. R. Burns ◽

Kailey H. Pascoe ◽

Randall K. Kosaki

Keyword(s):

Fractal Dimension ◽

Coral Reefs ◽

Habitat Structure ◽

Coral Cover ◽

Three Dimensional ◽

Structural Complexity ◽

Coralline Algae ◽

Crustose Coralline Algae ◽

Surface Areas ◽

Abundance And Diversity

Quantifying the three-dimensional (3D) habitat structure of coral reefs is an important aspect of coral reef monitoring, as habitat architecture affects the abundance and diversity of reef organisms. Here, we used photogrammetric techniques to generate 3D reconstructions of coral reefs and examined relationships between benthic cover and various habitat metrics obtained at six different resolutions of raster cells, ranging from 1 to 32 cm. For metrics of 3D structural complexity, fractal dimension, which utilizes information on 3D surface areas obtained at different resolutions, and vector ruggedness measure (VRM) obtained at 1-, 2- or 4-cm resolution correlated well with benthic cover, with a relatively large amount of variability in these metrics being explained by the proportions of corals and crustose coralline algae. Curvature measures were, on the other hand, correlated with branching and mounding coral cover when obtained at 1-cm resolution, but the amount of variability explained by benthic cover was generally very low when obtained at all other resolutions. These results show that either fractal dimension or VRM obtained at 1-, 2- or 4-cm resolution, along with curvature obtained at 1-cm resolution, can effectively capture the 3D habitat structure provided by specific benthic organisms.

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Coral reef carbonate budgets and ecological drivers in the central Red Sea – a naturally high temperature and high total alkalinity environment

Biogeosciences ◽

10.5194/bg-15-6277-2018 ◽

2018 ◽

Vol 15 (20) ◽

pp. 6277-6296 ◽

Cited By ~ 9

Author(s):

Anna Roik ◽

Till Röthig ◽

Claudia Pogoreutz ◽

Vincent Saderne ◽

Christian R. Voolstra

Keyword(s):

Red Sea ◽

Coral Cover ◽

Abiotic Factors ◽

Growth Dynamics ◽

Ocean Basin ◽

Total Alkalinity ◽

Coralline Algae ◽

Reef Growth ◽

Western Atlantic ◽

Growth Metrics

Abstract. The structural framework provided by corals is crucial for reef ecosystem function and services, but high seawater temperatures can be detrimental to the calcification capacity of reef-building organisms. The Red Sea is very warm, but total alkalinity (TA) is naturally high and beneficial for reef accretion. To date, we know little about how such detrimental and beneficial abiotic factors affect each other and the balance between calcification and erosion on Red Sea coral reefs, i.e., overall reef growth, in this unique ocean basin. To provide estimates of present-day reef growth dynamics in the central Red Sea, we measured two metrics of reef growth, i.e., in situ net-accretion/-erosion rates (Gnet) determined by deployment of limestone blocks and ecosystem-scale carbonate budgets (Gbudget), along a cross-shelf gradient (25 km, encompassing nearshore, midshore, and offshore reefs). Along this gradient, we assessed multiple abiotic (i.e., temperature, salinity, diurnal pH fluctuation, inorganic nutrients, and TA) and biotic (i.e., calcifier and epilithic bioeroder communities) variables. Both reef growth metrics revealed similar patterns from nearshore to offshore: net-erosive, neutral, and net-accretion states. The average cross-shelf Gbudget was 0.66 kg CaCO3 m−2 yr−1, with the highest budget of 2.44 kg CaCO3 m−2 yr−1 measured in the offshore reef. These data are comparable to the contemporary Gbudgets from the western Atlantic and Indian oceans, but lie well below “optimal reef production” (5–10 kg CaCO3 m−2 yr−1) and below maxima recently recorded in remote high coral cover reef sites. However, the erosive forces observed in the Red Sea nearshore reef contributed less than observed elsewhere. A higher TA accompanied reef growth across the shelf gradient, whereas stronger diurnal pH fluctuations were associated with negative carbonate budgets. Noteworthy for this oligotrophic region was the positive effect of phosphate, which is a central micronutrient for reef building corals. While parrotfish contributed substantially to bioerosion, our dataset also highlights coralline algae as important local reef builders. Altogether, our study establishes a baseline for reef growth in the central Red Sea that should be useful in assessing trajectories of reef growth capacity under current and future ocean scenarios.

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Interplay of hydrogen bonds, iodo...nitro interactions and aromatic π...π stacking interactions in iodo-nitroanilines

Acta Crystallographica Section B Structural Science ◽

10.1107/s0108768102007978 ◽

2002 ◽

Vol 58 (4) ◽

pp. 701-709 ◽

Cited By ~ 15

Author(s):

Simon J. Garden ◽

Silvia P. Fontes ◽

James L. Wardell ◽

Janet M. S. Skakle ◽

John N. Low ◽

...

Keyword(s):

Hydrogen Bonds ◽

Nitro Group ◽

Three Dimensional ◽

Dimensional Structure ◽

Single Type ◽

Stacking Interactions ◽

Π Stacking ◽

Independent Molecules ◽

Related Compounds ◽

Centrosymmetric Dimers

Molecules of 2-iodo-5-nitroaniline (I) are linked by N—H...O hydrogen bonds into centrosymmetric dimers and by asymmetric three-centre iodo...nitro interactions into chains, so forming chains of fused centrosymmetric rings: these chains are linked by aromatic π...π stacking interactions to form a three-dimensional structure. In the isomeric 4-iodo-2-nitroaniline (II), each of the two independent molecules forms hydrogen-bonded chains that are linked by two-centre iodo...nitro interactions into sheets of two types, each containing only a single type of molecule: π...π stacking interactions are absent. In 2,4-diiodo-3-nitroaniline (III), where the nitro group is almost orthogonal to the aryl ring, a combination of N—H...O hydrogen bonds and two distinct two-centre iodo...nitro interactions links the molecules into a three-dimensional framework that is reinforced by aromatic π...π stacking interactions. Bond lengths and conformations are discussed and comparisons are drawn with related compounds.

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