The biology of the glutamatergic system and potential role in migraine

Migraine is a common genetically linked neurovascular disorder. Approximately ~12% of the Caucasian population are affected including 18% of adult women and 6% of adult men (1, 2). A notable female bias is observed in migraine prevalence studies with females affected ~3 times more than males and is credited to differences in hormone levels arising from reproductive achievements. Migraine is extremely debilitating with wide-ranging socioeconomic impact significantly affecting people's health and quality of life. A number of neurotransmitter systems have been implicated in migraine, the most studied include the serotonergic and dopaminergic systems. Extensive genetic research has been carried out to identify genetic variants that may alter the activity of a number of genes involved in synthesis and transport of neurotransmitters of these systems. The biology of the Glutamatergic system in migraine is the least studied however there is mounting evidence that its constituents could contribute to migraine. The discovery of antagonists that selectively block glutamate receptors has enabled studies on the physiologic role of glutamate, on one hand, and opened new perspectives pertaining to the potential therapeutic applications of glutamate receptor antagonists in diverse neurologic diseases. In this brief review, we discuss the biology of the Glutamatergic system in migraine outlining recent findings that support a role for altered Glutamatergic neurotransmission from biochemical and genetic studies in the manifestation of migraine and the implications of this on migraine treatment.

Breeding and fecundity of the endemic Australian gudgeon, sleepy cod Oxyeleotris lineolatus (Steindachner 1867) (Eleotridae)

Sleepy cod (Oxyeleotris lineolatus Steindachner) is a tropical species of eleotrid native to northern Australia. A related species, sand or marbled goby, is the highest priced freshwater fish in Asia, and a market for a similar fish exists in expatriate Chinese communities. Sleepy cod breed when minimum temperatures reach 24 °C for more than 3 days. During the breeding season the genital papilla is broad and flattened in females compared to the triangular papilla of males and juveniles. Spawning pairs were usually of approximately equal size. Females could spawn up to 10 times during one breeding season. Wet weather increased the frequency of spawning. Eggs were usually laid hanging from the underside of a surface. Most spawning occurred between 05:00 and 10:00 h. Females attended egg masses immediately after spawning, after which males cared for eggs until hatching, 3–5 days later. Agitation of the egg mass was essential for development. The mean number of eggs per spawning was 43 130. Larvae commenced feeding 2–5 days after hatching, on plankton from 100 to 250 m in size. A spawning trap used to collect egg masses is described. The breeding biology of sleepy cod is considered to be an adaptation to the monsoonal tropics.

Spatial patterns in the biology of the chokka squid, Loligo reynaudii on the Agulhas Bank, South Africa

Although migration patterns for various life history stages of the chokka squid (Loligo reynaudii) have been previously presented, there has been limited comparison of spatial variation in biological parameters. Based on data from research surveys; size ranges of juveniles, subadults and adults on the Agulhas Bank were estimated and presented spatially. The bulk of the results appear to largely support the current acceptance of the life cycle with an annual pattern of squid hatching in the east, migrating westwards to offshore feeding grounds on the Central and Western Agulhas Bank and the west coast and subsequent return migration to the eastern inshore areas to spawn. The number of adult animals in deeper water, particularly in autumn in the central study area probably represents squid spawning in deeper waters and over a greater area than is currently targeted by the fishery. The distribution of life history stages and different feeding areas does not rule out the possibility that discrete populations of L. reynaudii with different biological characteristics inhabit the western and eastern regions of the Agulhas Bank. In this hypothesis, some mixing of the populations does occur but generally squid from the western Agulhas Bank may occur in smaller numbers, grow more slowly and mature at a larger size. Spawning occurs on the western portion of the Agulhas Bank, and juveniles grow and mature on the west coast and the central Agulhas Bank. Future research requirements include the elucidation of the age structure of chokka squid both spatially and temporally, and a comparison of the statolith chemistry and genetic characterisation between adults from different spawning areas across the Agulhas Bank.

The host range and biology of Cometaster pyrula; a biocontrol agent for Acacia nilotica subsp. indica in Australia

Prickly acacia, Acacia nilotica subsp. indica (Benth.) Brenan, a major weed of the Mitchell Grass Downs of northern Queensland, Australia, has been the target of biological control projects since the 1980s. The leaf-feeding caterpillar Cometaster pyrula (Hopffer) was collected from Acacia nilotica subsp. kraussiana (Benth.) Brenan during surveys in South Africa to find suitable biological control agents, recognised as a potential agent, and shipped into a quarantine facility in Australia. Cometaster pyrula has a life cycle of approximately 2 months during which time the larvae feed voraciously and reach 6 cm in length. Female moths oviposit a mean of 339 eggs. When presented with cut foliage of 77 plant species, unfed neonates survived for 7 days on only Acacia nilotica subsp. indica and Acacia nilotica subsp. kraussiana. When unfed neonates were placed on potted plants of 14 plant species, all larvae except those on Acacia nilotica subsp. indica and Acacia nilotica subsp. kraussiana died within 10 days of placement. Cometaster pyrula was considered to be highly host specific and safe to release in Australia. Permission to release C. pyrula in Australia was obtained and the insect was first released in north Queensland in October 2004. The ecoclimatic model CLIMEX indicated that coastal Queensland was climatically suitable for this insect but that inland areas were only marginally suitable.

Harvest strategy evaluation to optimise the sustainability and value of the Queensland scallop fishery. Queensland scallop fishery - FRDC Project No 2006/024 Final Report

Objective 1. Measure spatial and temporal trawl frequency of scallop grounds using VMS data. This will provide a relative measure of how often individual undersized scallops are caught and put through a tumbler 2. Estimate discard mortality and growth rates for saucer scallops using cage experiments. 3. Evaluate the current management measures, in particular the seasonal closure, rotational closure and seasonally varying minimum legal sizes using stock assessment and management modeling models. Recommend optimal range of management measures to ensure long-term viability and value of the Scallop fishery based on a formal management strategy evaluation. Outcomes acheived to date: 1. Improved understanding of the survival rates of discarded sub-legal scallops; 2. Preliminary von Bertalanffy growth parameters using data from tagged-and-released scallops; 3. Changing trends in vessels and fishing gear used in the Queensland scallop fishery and their effect on scallop catch rates over time using standardised catch rates quantified; 4. Increases in fishing power of vessels operating in the Queensland scallop fishery quantified; 5. Trawl intensity mapped and quantified for all Scallop Replenishment Areas; 6. Harvest Strategy Evaluations completed.

Insect induced bud fall in cultivated hibiscus and aspects of the biology of Macroura concolor (Macleay) (Coleoptera: Nitidulidae)

The influence of insect attack on bud fall and subsequent poor flowering in cultivated hibiscus (Hibiscus rosa-sinensis) was studied in cages and in the field in southern Queensland. Three species of Hemiptera (most importantly Aulacosternum nigrorubrum but also Nezara viridula and Tectocoris diophthalmus) caused some bud fall in 2 plantations studied. Adults of Macroura concolor suppressed flowering for long periods in spring and summer. Data from white funnel traps and counts in flowers showed that M. concolor was most active in these seasons. Methiocarb (0.75 g a.i./litre) reduced beetle numbers and increased flowering. When 15 or more adults of M. concolor occurred per bud (or flower) most buds fell and few flowers were produced, but when beetles declined to 10 or fewer many buds survived and widespread flowering occurred. Larvae fed in fallen buds and flowers and the mean duration of development of the combined immature stages was 14 days at 26 deg C. The preference of adults of M. concolor for pale coloured flowers was examined. Hibiscus plants produced most buds from December to June with lower numbers in winter and spring (July to November). Bud production in spring and early summer (September-December) varied greatly and probably contributed to poor flowering, however, even when large numbers of buds occurred very few flowers were produced because of the activities of M. concolor.

Evolutionary and conservation biology of the Finnish house sparrow

Recently it has been recognized that evolutionary aspects play a major role in conservation issues of a species. In this thesis I have combined evolutionary research with conservation studies to provide new insight into these fields. The study object of this thesis is the house sparrow, a species that has features that makes it interesting for this type of study. The house sparrow has been ubiquitous almost all over the world. Even though being still abundant, several countries have reported major declines. These declines have taken place in a relatively short time covering both urban and rural habitats. In Finland this species has declined by more than two thirds in just over two decades. In addition, as the house sparrow lives only in human inhabited areas it can also raise public awareness to conservation issues. I used both an extensive museum collection of house sparrows collected in 1980s from all over Finland as well as samples collected in 2009 from 12 of the previously collected localities. I used molecular techniques to study neutral genetic variation within and genetic differentiation between the study populations. This knowledge I then combined with data gathered on morphometric measurements. In addition I analyzed eight heavy metals from the livers of house sparrows that lived in either rural or urban areas in the 1980s and evaluated the role of heavy metal pollution as a possible cause of the declines. Even though dispersal of house sparrows is limited I found that just as the declines started in 1980s the house sparrows formed a genetically panmictic population on the scale of the whole Finland. When compared to Norway, where neutral genetic divergence has been found even with small geographic distances, I concluded that this difference would be due to contrasting landscapes. In Finland the landscape is rather homogeneous facilitating the movements of these birds and maintaining gene flow even with the low dispersal. To see whether the declines have had an effect on the neutral genetic variation of the populations I did a comparison between the historical and contemporary genetic data. I showed that even though genetic diversity has not decreased due to the drastic declines the populations have indeed become more differentiated from each other. This shows that even in a still quite abundant species the declines can have an effect on the genetic variation. It is shown that genetic diversity and differentiation may approach their new equilibriums at different rates. This emphasizes the importance of studying both of them and if the latter has increased it should be taken as a warning sign of a possible loss of genetic diversity in the future. One of the factors suggested to be responsible for the house sparrow declines is heavy metal pollution. When studying the livers of house sparrows from 1980s I discovered higher levels of heavy metal concentrations in urban than rural habitats, but the levels of the metals were comparatively low and based on that heavy metal pollution does not seem to be a direct cause for the declines in Finland. However, heavy metals are known to decrease the amount of insects in urban areas and thus in the cities heavy metals may have an indirect effect on house sparrows. Although neutral genetic variation is an important tool for conservation genetics it does not tell the whole story. Since neutral genetic variation is not affected by selection, information can be one-sided. It is possible that even neutral genetic differentiation is low, there can be substantial variation in additive genetic traits indicating local adaptation. Therefore I performed a comparison between neutral genetic differentiation and phenotypic differentiation. I discovered that two traits out of seven are likely to be under directional selection, whereas the others could be affected by random genetic drift. Bergmann s rule may be behind the observed directional selection in wing length and body mass. These results highlight the importance of estimating both neutral and adaptive genetic variation.

Recent Developments in the Chemistry and Biology of G-Quadruplexes with Reference to the DNA Groove Binders

DNA is the chemotherapeutic target for treating diseases of genetic origin. Besides well-known double-helical structures (A, B, Z, parallel stranded-DNA etc.), DNA is capable of forming several multi-stranded structures (triplex, tetraplex, i-motif etc.) which have unique biological significance. The G-rich 3'-ends of chromosomes, called telomeres, are synthesized by telomerase, a ribonucleoprotein, and over-expression of telomerase is associated with cancer. The activity of telomerase is suppressed if the G-rich region is folded into the four stranded structures, called G-quadruplexes (G4-DNAs) using small synthetic ligands. Thus design and synthesis of new G4-DNA ligands is an attractive strategy to combat cancer. G4-DNA forming sequences are also prevalent in other genomic regions of biological significance including promoter regions of several oncogenes. Effective gene regulation may be achieved by inducing a G4-DNA structure within the G-rich promoter sequences. To date, several G4-DNA stabilizing ligands are known. DNA groove binders interact with the duplex B-DNA through the grooves (major and minor groove) in a sequence-specific manner. Some of the groove binders are known to stabilize the G4-DNA. However, this is a relatively under explored field of research. In this review, we focus on the recent advances in the understanding of the G4-DNA structures, particularly made from the human telomeric DNA stretches. We summarize the results of various investigations of the interaction of various organic ligands with the G4-DNA while highlighting the importance of groove binder-G4-DNA interactions.

Status and management of the sea cucumber fishery of La Grande Terre, New Caledonia

From October 2006 to May 2008, The WorldFish Center coordinated a ZoNéCo project to provide support to the Southern and Northern Provinces for decisions about how best to manage the sea cucumber fishery around La Grande Terre. We collected data during underwater population surveys, questionnaire-based interviews with fishers and processors, and landing catch surveys. A core aim was to furnish the Provinces with ‘ballpark’ estimates of the abundance and density of commercially important sea cucumbers on 50 lagoon and barrier reefs. Analysis and synthesis of the ecological and sociological data provide the basis for informed recommendations for fisheries management. Counts of trochus and giant clams on the reefs allow us to also describe the general status of those resources. We propose 13 recommendations for management actions and fishery regulations and advocate an adaptive management approach. This multidisciplinary study should serve as a useful template for assessing other fisheries, and we provide a series of generic ‘lessons learnt’ to aid future programmes. (PDF has 140 pages.)

Aquaculture and marketing of the Florida Bay Scallop in Crystal River, Florida

The overall goal of this study was to develop a new fishery resource product through open-water aquaculture for the west coast of Florida that would compete as a non-traditional product through market development. Specific objectives were as follows: I. To grow a minimum of 50, 000 juvenile scallops to a minimum market size of40 mm in a cage and float system in the off-shore waters of Crystal River, Florida. 2. To determine the growth rate, survival, and time to market size for the individuals in this system and area to other similar projects like Virginia. 3. To introduce local fishermen and the aquaculture students at Crystal River High School to the hatchery, nursery, and grow-out techniques. 4. To determine the economic and financial characteristics of bay scallop culture in Florida and assess the sensitivity of projected costs and earnings to changes in key technical, managerial, and market related parameters. 5. To determine the market acceptability and necessary marketing strategy for whole bay scallop product in Florida. (PDF has 99 pages.)

Biology, ecology, control and management of the invasive Indo-Pacific lionfish: An updated integrated assessment

Venomous Indo-Pacific lionfish (Pterois miles and P. volitans) are now established along the Southeast U.S.A. and parts of the Caribbean and pose a serious threat to reef fish communities of these regions. Lionfish are likely to invade the Gulf of Mexico and potentially South America in the near future. Introductions of lionfish were noted since the 1980s along south Florida and by 2000 lionfish were established off the coast of North Carolina. Lionfish are now one of the more numerous predatory reef fishes at some locations off the Southeast U.S.A. and Caribbean. Lionfish are largely piscivores that feed occasionally on economically important reef fishes. The trophic impacts of lionfish could alter the structure of native reef fish communities and potentially hamper stock rebuilding efforts of the Snapper –Grouper Complex. Additional effects of the lionfish invasion are far-reaching and could increase coral reef ecosystem stress, threaten human health, and ultimately impact the marine aquarium industry. Control strategies for lionfish are needed to mitigate impacts, especially in protected areas. This integrated assessment provides a general overview of the biology and ecology of lionfish including genetics, taxonomy, reproductive biology, early life history and dispersal, venom defense and predation, and feeding ecology. In addition, alternative management actions for mitigating the negative impacts of lionfish, approaches for reducing the risk of future invasions, and directions for future research are provided.