The need for broader ecological and socioeconomic tools to evaluate the effectiveness of coral restoration programs

Coral reef restoration initiatives are burgeoning in response to the need for novel management strategies to address dramatic global declines in coral cover. However, coral restoration programs typically lack rigor and critical evaluation of their effectiveness. A review of 83 peer‐reviewed papers that used coral transplantation for reef restoration reveals that growth and survival of coral fragments were the most widely used indicators of restoration success, with 88% of studies using these two indicators either solely (55%) or in combination with a limited number of other ecological factors (33%). In 53% of studies, reef condition was monitored for 1 year or less, while only 5% of reefs were monitored for more than 5 years post‐transplantation. These results highlight that coral reef restoration science has focused primarily on short‐term experiments to evaluate the feasibility of techniques for ecological restoration and the initial establishment phase post‐transplantation, rather than on longer‐term outcomes for coral reef communities. Here, we outline 10 socioecological indicators that comprehensively evaluate the effectiveness of coral reef restoration across the four pillars of sustainability (i.e. environmental, sociocultural, governance, and economic contributions to sustainable communities). We recommend that evaluations of the effectiveness of coral restoration programs integrate ecological indicators with sociocultural, economic, and governance considerations. Assessing the efficacy of coral restoration as a tool to support reef resilience will help to guide future efforts and ensure the sustainable maintenance of reef ecosystem goods and services.     

Neuroecology and diet selection in phyllostomid bats

For many birds and mammals relative brain and hippocampus volume are positively related to enhanced behavioral flexibility and spatial memory. I tested for correlations between species-specific diet selection and relative brain and hippocampus volumes in the New World leaf-nosed bats (Phyllostomidae). To this end, I classified each of 53 species from this ecologically diverse family as one of the following: (i) predatory, (ii) omnivorous, (iii) frugivorous, or (iv) nectivorous. Species-level analyses and the comparative method (i.e. phylogenetically independent contrasts) revealed that relative hippocampus volume was greater in predatory species than in frugivorous and nectivorous species and that relative brain size was greater in frugivorous species than in predatory species. As previously reported, specialized frugivory appears to be associated with increased relative brain volume suggesting these two traits evolve together. I suggest some plausible functional explanations for variation in hippocampus volume in light of our current understanding of the acquisition of spatial information and its use by echolocating bats.     

Neuroecology, chemical defense, and the keystone species concept

Neuroecology unifies principles from diverse disciplines, scaling from biophysical properties of nerve and muscle cells to community-wide impacts of trophic interactions. Here, these principles are used as a common fabric, woven from threads of chemosensory physiology, behavior, and population and community ecology. The "keystone species" concept, for example, is seminal in ecological theory. It defines a species whose impacts on communities are far greater than would be predicted from its relative abundance and biomass. Similarly, neurotoxins could function in keystone roles. They are rare within natural habitats but exert strong effects on species interactions at multiple trophic levels. Effects of two guanidine alkaloids, tetrodotoxin (TTX) and saxitoxin (STX), coalesce neurobiological and ecological perspectives. These molecules compose some of the most potent natural poisons ever described, and they are introduced into communities by one, or only a few, host species. Functioning as voltage-gated sodium channel blockers for nerve and muscle cells, TTX and STX serve in chemical defense. When borrowed by resistant consumer species, however, they are used either in chemical defense against higher order predators or for chemical communication as chemosensory excitants. Cascading effects of the compounds profoundly impact community-wide attributes, including species compositions and rates of material exchange. Thus, a diverse array of physiological traits, expressed differentially across many species, renders TTX and STX fully functional as keystone molecules, with vast ecological consequences at multiple trophic levels.     

Neuroecology: avoiding the unpleasant experience of being the uninvited guest

The navigation system of the desert ant Cataglyphis fortis helps it avoid the lethal mistake of entering the wrong nest by suppressing its attraction to nest odors until it is near its home.     

Neuroecology of cartilaginous fishes: the functional implications of brain scaling

It is a widely accepted view that neural development can reflect morphological adaptations and sensory specializations. The aim of this review is to give a broad overview of the current status of brain data available for cartilaginous fishes and examine how perspectives on allometric scaling of brain size across this group of fishes has changed within the last 50 years with the addition of new data and more rigorous statistical analyses. The current knowledge of neuroanatomy in cartilaginous fishes is reviewed and data on brain size (encephalization, n = 151) and interspecific variation in brain organization (n = 84) has been explored to ascertain scaling relationships across this clade. It is determined whether similar patterns of brain organization, termed cerebrotypes, exist in species that share certain lifestyle characteristics. Clear patterns of brain organization exist across cartilaginous fishes, irrespective of phylogenetic grouping and, although this study was not a functional analysis, it provides further evidence that chondrichthyan brain structures might have developed in conjunction with specific behaviours or enhanced cognitive capabilities. Larger brains, with well-developed telencephala and large, highly foliated cerebella are reported in species that occupy complex reef or oceanic habitats, potentially identifying a reef-associated cerebrotype. In contrast, benthic and benthopelagic demersal species comprise the group with the smallest brains, with a relatively reduced telencephalon and a smooth cerebellar corpus. There is also evidence herein of a bathyal cerebrotype; deep-sea benthopelagic sharks possess relatively small brains and show a clear relative hypertrophy of the medulla oblongata. Despite the patterns observed and documented, significant gaps in the literature have been highlighted. Brain mass data are only currently available on c. 16% of all chondrichthyan species, and only 8% of species have data available on their brain organization, with far less on subsections of major brain areas that receive distinct sensory input. The interspecific variability in brain organization further stresses the importance of performing functional studies on a greater range of species. Only an expansive data set, comprised of species that span a variety of habitats and taxonomic groups, with widely disparate behavioural repertoires, combined with further functional analyses, will help shed light on the extent to which chondrichthyan brains have evolved as a consequence of behaviour, habitat and lifestyle in addition to phylogeny.     

A plea for a broader ethnomedicine

A plea for a broader ethnomedicine     

The Neuroecology of the Elasmobranch Electrosensory World: Why Peripheral Morphology Shapes Behavior

The adaptations of elasmobranch sensory systems can be studied by linking the morphological structure with the natural behavior and ecology of the organism. This paper presents the first step in a neuroecological approach to interpret the spatial arrangement of the electrosensory ampullary organs in elasmobranch fishes. A brief review of the structure and function of the ampullae of Lorenzini is provided for interpretation of the organ system morphology in relation to the detection of dipole and uniform electric fields. The spatial projections of canals from discrete ampullary clusters were determined for the barndoor skate, Raja laevis, based upon a published figure in Raschi (1986), and measured directly from the head of the white shark, Carcharodon carcharias. The dorsoventrally flattened body of the skate restricts the projections of long canals to the horizontal plane. There is a distinct difference between dorsal and ventral projection patterns in all groups. Notable within-cluster features include a relatively long canal subgroup in the dorsal superficial ophthalmic (SOd) and dorsal hyoid (HYOd) clusters that are oriented parallel (bidirectionally) to the longitudinal axis of the body. It is postulated that this subgroup of canals may be important for detection and orientation to weak uniform fields. Ventral canal projections in the skate are primarily lateral, with the exception of the hyoid (HYOv) that also projects medially. This wide dispersion may function for the detection of prey located below the body and pectoral fins of the skate, and may also be used for orientation behavior. The mandibular canals located near the margin of the lower jaw (of both study species) are ideally positioned for use during prey manipulation or capture, and possibly for interspecific courtship or biting. The head of the white shark, which lacks the hyoid clusters, is ovoid in cross section and thus ampullary canals can project into three-dimensional space. The SOd and superficial ophthalmic ventral (SOv) clusters show strong rostral, dorsal and lateral projection components, whereas the SOv also detects rostral fields under the snout. In the sagittal plane, the SOv and SOd have robust dorsal projections as well as ventral in the SOv. Most notable are canal projections in the white shark buccal (BUC) ampullary cluster, which has a radial turnstile configuration on the ventrolateral side of the snout. The turnstile design and tilt between orthogonal planes indicates the white shark BUC may function in detection of uniform fields, including magnetically induced electric fields that may be used in orientation behaviors. These data can be used in future neuroecology behavioral performance experiments to (1) test for possible specializations of cluster groups to different natural electric stimuli, (2) the possibility of specialized canal subgroups within a cluster, and (3) test several models of navigation that argue for the use of geomagnetically induced electric cues.     

A broader view of conservation

A review of Conservation in a Changing World, edited by Georgina M. Mace, Andrew Balmford, and Joshua R. Ginsburg. Cambridge, Cambridge University Press, 1998, 308 pp. $80.00 hard bound; $34.95 paperback.     

Lipophilic prodrug conjugates allow facile and rapid synthesis of high-loading capacity liposomes without the need for post-assembly purification

Abstract

Dihydropyridopyrazoles are simplified synthetic analogues of podophyllotoxin that can effectively mimic its molecular scaffold and act as potent mitotic spindle poisons in dividing cancer cells. However, despite nanomolar potencies and ease of synthetic preparation, further clinical development of these promising anticancer agents is hampered due to their poor aqueous solubility. In this article, we developed a prodrug strategy that enables incorporation of dihydropyridopyrazoles into liposome bilayers to overcome the solubility issues. The active drug was covalently connected to either myristic or palmitic acid anchor via carboxylesterase hydrolyzable linkage. The resulting prodrugs were self-assembled into liposome bilayers from hydrated lipid films using ultrasound without the need for post-assembly purification. The average particle size of the prodrug-loaded liposomes was about 90?nm. The prodrug incorporation was verified by differential scanning calorimetry, spectrophotometry and gel filtration reaching maximum at 0.3 and 0.35 prodrug/lipid molar ratios for myristic and palmitic conjugates, respectively. However, the ratio of 0.2 was used in the particle size and biological activity experiments to maintain long-term stability of the prodrug-loaded liposomes against phase separation during storage. Antiproliferative activity was tested against HeLa and Jurkat cancer cell lines in vitro showing that the liposomal prodrug retained antitubulin activity of the parent drug and induced apoptosis-mediated cancer cell death. Overall, the established data provide a powerful platform for further clinical development of dihydropyridopyrazoles using liposomes as the drug delivery system.     

A weak link in metabolism: the metabolic capacity for glycine biosynthesis does not satisfy the need for collagen synthesis

In a previous paper, we pointed out that the capability to synthesize glycine from serine is constrained by the stoichiometry of the glycine hydroxymethyltransferase reaction, which limits the amount of glycine produced to be no more than equimolar with the amount of C 1 units produced. This constraint predicts a shortage of available glycine if there are no adequate compensating processes. Here, we test this prediction by comparing all reported fluxes for the production and consumption of glycine in a human adult. Detailed assessment of all possible sources of glycine shows that synthesis from serine accounts for more than 85% of the total, and that the amount of glycine available from synthesis, about 3 g/day, together with that available from the diet, in the range 1.5–3.0 g/day, may fall significantly short of the amount needed for all metabolic uses, including collagen synthesis by about 10 g per day for a 70 kg human. This result supports earlier suggestions in the literature that glycine is a semi-essential amino acid and that it should be taken as a nutritional supplement to guarantee a healthy metabolism.