bluuebunny/crossref_metadata_2025 huggingface dataset:
Hunting Increases Dispersal Limitation in the TreeCarapa procera, a Nontimber Forest Product
Authors: FORGET PIERRE‐MICHEL , JANSEN PATRICK A.
Published: November 2006

Abstract: The sustainability of seed extraction from natural populations has been questioned recently. Increased recruitment failure under intense seed harvesting suggests that seed extraction intensifies source limitation. Nevertheless, areas where more seeds are collected tend to also have more intense hunting of seed‐dispersing animals. We studied whether such hunting, by limiting disperser activity, could cause quantitative dispersal limitation, especially for large crops and for crops in years of high seed abundance. In each of fourCarapa procera(Meliaceae) populations in French Guiana and Surinam, two with hunting and two without, we compared seed fate for individual trees varying in crop size in years of high and low population‐level seed abundance.Carapaseeds are a nontimber forest product and depend on dispersal by scatter‐hoarding rodents for survival and seedling establishment. Hunting negatively affected the proportion of seeds dispersed and caused greater numbers of seeds to germinate or be infested by moths below parent trees, where they would likely die. Hunting of seed‐dispersing animals disproportionally affected large seed crops, but we found no additional effect of population‐level seed abundance on dispersal rates. Consistently lower rates of seed dispersal, especially for large seed crops, may translate to lower levels of seedling recruitment under hunting. Our results therefore suggest that the subsistence hunting that usually accompanies seed collection is at the cost of seed dispersal and may contribute to recruitment failure of these nontimber forest products. Seed extraction from natural populations may affect seedling recruitment less if accompanied by measures adequately incorporating and protecting seed dispersers.
Putting Longline Bycatch of Sea Turtles into Perspective
Authors: LEWISON REBECCA L. , CROWDER LARRY B.
Published: November 2006

Abstract:  Although some sea turtle populations are showing encouraging signs of recovery, others continue to decline. Reversing population declines requires an understanding of the primary factor(s) that underlie this persistent demographic trend. The list of putative factors includes direct turtle and egg harvest, egg predation, loss or degradation of nesting beach habitat, fisheries bycatch, pollution, and large‐scale changes in oceanographic conditions and nutrient availability. Recently, fisheries bycatch, in particular bycatch from longline fisheries, has received increased attention and has been proposed as a primary source of turtle mortality. We reviewed the existing data on the relative impact of longline bycatch on sea turtle populations. Although bycatch rates from individual longline vessels are extremely low, the amount of gear deployed by longline vessels suggests that cumulative bycatch of turtles from older age classes is substantial. Current estimates suggest that even if pelagic longlines are not the largest single source of fisheries‐related mortality, longline bycatch is high enough to warrant management actions in all fleets that encounter sea turtles. Nevertheless, preliminary data also suggest that bycatch from gillnets and trawl fisheries is equally high or higher than longline bycatch with far higher mortality rates. Until gillnet and trawl fisheries are subject to the same level of scrutiny given to pelagic longlines, our understanding of the overall impact of fisheries bycatch on vulnerable sea turtle populations will be incomplete.
Correlation Between Carcinogenic Potency of Chemicals in Animals and Humans
Authors: Allen Bruce C. , Crump Kenny S. , Shipp Annette M.
Published: November 2006

Twenty‐three chemicals were selected for comparison of the carcinogenic potencies estimated from epidemiological data to those estimated from animal carcinogenesis bioassays. The chemicals were all those for which reasonably strong evidence of carcinogenicity could be found in humans or animals and for which suitable data could be obtained for quantifying carcinogenic potencies in both humans and animals. Many alternative methods of analyzing the bioassay data were investigated. Almost all of the methods yielded potency estimates that were highly correlated with potencies estimated from epidemiological data; correlations were highly statistically significant (p < 0.001), with the corresponding correlation coefficients ranging as high as 0.9. These findings provide support for the general use of animal data to evaluate carcinogenic potential in humans and also for the use of animal data to quantify human risk.
Evaluation of the Quality of Safety and Risk Analysis in the Chemical Industry
Authors: Suokas Jouko
Published: November 2006

Safety and risk analyses have often been criticized as incomplete and inaccurate. This criticism, however, lacks a sound basis, since there has been little scientific evaluation of the methods developed for safety and risk analysis. The aim of this paper is to present a proposal for establishing measures—reliability, validity, and coverage—to be used in the evaluation of the scientific quality of the hazard identification and accident modeling phases in safety and risk analysis. The paper also presents four main principles for the evaluation of the scientific quality, and a theoretical framework to be used in evaluation. The framework is illustrated with practical examples taken from the chemical industry.
Comparing Expressed and Revealed Preferences for Risk Reduction: Different Hazards and Question Frames
Authors: McDaniels Timothy L.
Published: November 2006

Studies often note the wide differences that exist in costs per death avoided across U.S. federal programs and regulatory contexts. This paper explores two new, related explanations for these differences. First, it argues that the patterns of revealed preferences (public allocations) may be related to public values, which are measured here through subjects' expressed preference responses to a contingent valuation survey regarding risk reduction. Subjects' expressed values are compared to actual (and proposed) costs of safety regulations for a similar set of hazards. We discover strong congruence in the ranking of expressed values and actual values. Second, the paper presents the results of a subsequent survey that investigates why the patterns observed in the first survey might occur. It suggests that one reason for the observed similarities between revealed and expressed preferences may be in how choices are framed. The paper hypothesizes that both subjects and decision makers may frame valuation decisions in the same way: as percentage changes from the reference point provided by the base rate of deaths for that hazard.
Predictors Revised: Linguistic Knowledge and Metalinguistic Awareness in Second Language Gain in Russian
Authors: GOLONKA EWA M.
Published: November 2006

The empirical study reported here investigated predictors of oral proficiency gain to the Advanced level resulting from immersion study abroad. The data consisted of 22 preimmersion Oral Proficiency Interviews (OPIs) of American students who participated in semester immersion programs in Moscow and St. Petersburg, and received a score of Intermediate High on the preimmersion OPI. On the basis of the students’ postprogram proficiency scores, the participants were grouped as learners who crossed the Advanced‐level threshold (gainers) and as those who did not cross the threshold (nullgainers). This study used linguistic predictor variables identified in previous research (Brecht, Davidson, & Ginsberg, 1993) and introduced a new set of metalinguistic variables. An empirically based model constructed for the study included five variables that proved to be the best predictors for the Advanced‐level threshold gain: linguistic (grammar, vocabulary, accuracy) and metalinguistic (self‐corrected errors and sentence repair). The resulting findings yielded a robust model for predicting language outcomes of study abroad.
Negotiation of Meaning and Noticing in Text‐Based Online Chat
Authors: SHEKARY M. , TAHRIRIAN M. H.
Published: November 2006

The aim of this study was to explore the claim that the hybrid nature of synchronic computer‐mediated chat (SCMC) promotes the noticing of target language forms, which may, in turn, stimulate the process of second language actuation. When viewed in the context of interaction theory, the hybrid nature of SCMC makes online negotiation a potentially useful tool for collaborative second language (L2) learning. In the present study, the online negotiations of 16 English as a foreign language (EFL) Persian learners were investigated to determine the potential of SCMC for promoting noticing (operationalized as collaborative mini‐dialogues or language‐related episodes [LREs]) and to investigate its effectiveness. The study revealed that the learners did focus on form and that the ratio of LREs far exceeded those reported in previous offline settings. To determine the effectiveness of noticing, posttests were designed on the basis of specific linguistic items arising during the LREs, and the performance of learners on these test items was examined in immediate and delayed posttests. The results suggested that noticing in such contexts was associated with subsequent learning and that on the immediate posttests the learners were able to remember more than three fourths of the LREs. If long‐term retention is the ultimate goal of L2 learning, most importance should be attached to the correct responses on a delayed test. On these measures, the learners responded correctly 56.7% of the time. Given the incidental nature of noticing, this relatively slight decrease in performance by the learners on the delayed tests was encouraging. Considering the distribution of the characteristics of the LREs, logistic regression analysis revealed that successful uptake was the strongest predictor of correct responses. This result suggested that what was of most benefit to learners was the nature of the uptake, not its mere presence; therefore, learners need to produce successful uptake in order to receive the most benefit from online negotiation of meaning.
Supercritical Fluids and the Food Industry
Authors: Rozzi N.L. , Singh R.K.
Published: November 2006

This paper reviews the use of supercritical fluids in various aspects of the food industry, and is divided into six different areas: modeling of supercritical fluids, separation of extracted material, supercritical carbon dioxide as a solvent for extraction, supercritical fluids and analytical uses, and supercritical fluids and novel methods of food processing. An assortment of solutes are covered in the extraction section of the paper, including antineoplastic agents and lipids. The analytical methods section covers supercritical fluid chromatography, pesticide detection, and lipid analysis. The novel methods section discusses supercritical fluid extrusion and a new method of eliminating hexane from soybean oil.
Release and Transport of Flavors In Vivo: Physicochemical, Physiological, and Perceptual Considerations
Authors: Taylor A. J.
Published: November 2006

For flavor perception to occur, the chemicals responsible for flavor perception must be released from the food matrix and transported to the flavor receptors in the mouth and nose. The overall process is governed by the properties of the flavor compounds, the nature of the food matrix and the physiological conditions of the mouth, nose and throat during consumption of the food. These factors combine to determine the concentrations and rate at which the flavor chemicals reach the receptors, thus creating the characteristic flavor profile of a food. Physicochemical factors like partitioning, interfacial mass transport and diffusion are the typical mechanisms governing flavor release. Although the theory behind these factors is well understood, applying them to the situation in‐mouth during eating is difficult. This is because key parameters like surface area and flavor concentrations in the gas and liquid phases change rapidly with time as a result of the physiological processes occurring during eating. Furthermore, individuals vary in their rate of breathing, swallowing and salivation, which affects the transport of flavors from the saliva phase to receptors on the tongue and in the nose. This review covers all aspects of flavor release from food matrices and the subsequent delivery of flavor to the olfactory and gustatory receptors.
Chemistry and Reaction of Singlet Oxygen in Foods
Authors: Min D. B. , Boff J. M.
Published: November 2006

Singlet oxygen is a highly reactive, electrophilic, and nonradical molecule. It is different from diradical triplet oxygen in its electron arrangement. Photosensitizers can form singlet oxygen from triplet oxygen in the presence of light. The reaction rate of singlet oxygen with foods is much greater than that of triplet oxygen due to the low activation energy. Singlet oxygen oxidation produces undesirable compounds in foods during processing and storage. However, carotenoids and tocopherols in foods can minimize singlet oxygen oxidation. The in‐depth scientific knowledge on the formation, reactions, quenching mechanisms, and kinetics of singlet oxygen can greatly improve the quality of foods by minimizing the oxidation during processing and storage. The single oxygen oxidation of foods has contributed to the explanation of several important chemical reactions in the reversion flavor in soybean oil, sunlight flavor in milk products, and the rapid losses of vitamin D, riboflavin, and ascorbic acid in milk under light storage.
Human Enteric Viruses as Causes of Foodborne Disease
Authors: Sair A. I. , D'Souza D. H. , Jaykus L. A.
Published: November 2006

Recent epidemiological evidence indicates that enteric viruses are the leading cause of foodborne disease in the U.S.A. and, indeed, worldwide. Certainly, advances in epidemiology and molecular biology have improved the ability to study this previously elusive group of foodborne pathogens. The purpose of this article is to review the agents, transmission routes, epidemiology, persistence, diagnosis, and detection of foodborne viruses and their diseases, with specific reference to the role that contemporary technologies have had in improving our understanding of this important group of emerging foodborne pathogens.
Structured Lipids‐Novel Fats with Medical, Nutraceutical, and Food Applications
Authors: Osborn H.T. , Akoh C.C.
Published: November 2006

Generally, structured lipids (SLs) are triacylglycerols (TAGs) that have been modified to change the fatty acid composition and/or their positional distribution in glycerol backbone by chemically and/or enzymatically catalyzed reactions and/or genetic engineering. More specifically, SLs are modified TAGs with improved nutritional or functional properties. SLs provide an effective means for producing tailor‐made lipids with desired physical characteristics, chemical properties, and/or nutritional benefits. The production, commercialization outlook, medical, and food applications of SLs are reviewed here. Physical property measurements for SL in food systems and future research needs for increased industrial acceptance are also included in this review.
Bread Staling: Molecular Basis and Control
Authors: Gray J.A. , Bemiller J.N.
Published: November 2006

The molecular basis of staling is examined by reviewing what is known about the components of wheat flour, factors that affect staling rate, and the various mechanisms that have been proposed. The conclusion reached is that bread staling is a complex phenomenon in which multiple mechanisms operate. Polymer crystallizations with the formation of supermolecular structures are certainly involved. The most plausible hypothesis is that retrogradation of amylopectin occurs, and because water molecules are incorporated into the crystallites, the distribution of water is shifted from gluten to starch/amylopectin, thereby changing the nature of the gluten network. The role of additives may be to change the nature of starch protein molecules, to function as plasticizers, and/or to retard the redistribution of water between components. Nothing more definite can be concluded at this time.
Flavor Lexicons
Authors: Drake M.A. , Civille G.V.
Published: November 2006

Flavor lexicons are a widely used tool for documenting and describing sensory perception of a selected food. Development of a representative flavor lexicon requires several steps, including appropriate product frame of reference collection, language generation, and designation of definitions and references before a final descriptor list can be determined. Once developed, flavor lexicons can be used to record and define product flavor, compare products, and determine storage stability, as well as interface with consumer liking and acceptability and chemical flavor data.
Bacteriocins and their Food Applications
Authors: And H. Chen , Hoover D.G.
Published: November 2006

Over the last 2 decades, a variety of bacteriocins, produced by bacteria that kill or inhibit the growth of other bacteria, have been identified and characterized biochemically and genetically. This review article focuses on the ecology of bacteriocins, determination of bacteriocin activity, biosynthesis of bacteriocins, and mode of action. Bacteriocin production and modeling are discussed in the article. Nisin is discussed in some detail in this article since it is currently the only purified bacteriocin approved for food use in the U.S. and has been successfully used for several decades as a food preservative in more than 50 countries. For activity spectra and food applications, the review article focuses primarily on class I and class IIa bacteriocins produced by lactic acid bacteria (LAB) given their development as food preservatives.
Plant Cell Walls and Food Quality
Authors: Waldron K.W. , Parker M.L. , Smith A.C.
Published: November 2006

Plant cell walls constitute the key structural components of plants and many plant‐based foods. They are well known for contributing to a range of “quality” characteristics, from organoleptic texture to the properties of dietary fiber. Much of the research on cell walls has focused on the physiological aspects of plant growth and development with the belief that this route holds the key to controlling quality characteristics. In addition, consideration of quality has often been determined by what is easily measurable. This review assesses critically the role of plant cell walls in relation to the ultimate determinant of quality – the consumer, but within a whole food‐chain context. We conclude that effective exploitation of cell‐wall research in relation to optimizing quality requires an integrated approach taking into account the multi‐functional roles of plant cell walls, and the diversity of consumer‐related quality dimensions.
Flavor of Cheddar Cheese: A Chemical and Sensory Perspective
Authors: Singh T.K. , Drake M.A. , Cadwallader K.R.
Published: November 2006

Considerable knowledge has been accumulated on the biochemical processes occurring during ripening of Cheddar cheese, which in turn has major consequences on flavor and texture development. The present review outlines major metabolic pathways and agents involved in the modification of milk constituents in Cheddar cheese ripening. Mechanisms of volatile flavor and off‐flavor production and recent developments in the analysis, both sensory and instrumental, of Cheddar flavor and flavor compounds are also detailed here.
The Use of Indicators and Surrogate Microorganisms for the Evaluation of Pathogens in Fresh and Fresh‐Cut Produce
Authors: Busta F.F. , Suslow T.V. , Parish M.E. , Beuchat L.R. , Farber J.N. , Garrett E.H. , Harris L.J.
Published: November 2006

4. Summary

Indicators and surrogate microorganisms may be used for evaluating safety of fresh or fresh‐cut fruit and vegetable products by assessing or validating the effectiveness of microbial control measures. Although frequently used on an informal basis within a specific company, use of indicators is highly dependent upon microbiological criteria that are in place for the specific produce item or category. All the considerations that must be addressed in establishing microbiological criteria must also be in place if indicators are to be utilized in process verification. Sampling design, stringency, and statistical significance are critical to the evaluation of indicators or surrogates in the assurance of food safety. General ideal qualities of indicators and surrogates are valuable starting points when developing a safety program. The importance of selecting the significant target pathogen for the specific product, its source, handling practices, and distribution practices cannot be overemphasized. The same is true for selection of the indicator or surrogate to represent those pathogens. The extensive lists of considerations and procedures should be helpful when using indicators and surrogates with fresh and fresh‐cut produce. The use and limitations of indicators and surrogates to determine or validate treatment effectiveness have been delineated. Challenges are identified for selection of an indicator or surrogate for the specific situation and conditions of an individual produce item, including growing, harvesting, processing, handling, storage, and packaging.
A Review of Oxygen Toxicity in Probiotic Yogurts: Influence on the Survival of Probiotic Bacteria and Protective Techniques
Authors: Talwalkar A. , Kailasapathy K.
Published: November 2006

Oxygen toxicity is considered a significant factor influencing the viability of probiotic bacteria such as Lactobacillus and Bifidobacterium spp. in yogurts. This review assesses the involvement of oxygen during the manufacture of yogurt and its diffusion into the final product. The oxygen sensitivity of Lactobacillus acidophilus and Bifidobacterium spp. is discussed. The impact of dissolved oxygen of the product on the survival of these probiotic bacteria is highlighted. Additionally, microbiological, chemical, and packaging techniques recommended to protect probiotic bacteria from oxygen toxicity in dairy products are reviewed.
Influence of Cosolvent Systems on the Gelation Mechanism of Globular Protein: Thermodynamic, Kinetic, and Structural Aspects of Globular Protein Gelation
Authors: Baier Stefan K. , McClements D. Julian
Published: November 2006

How thermostability and gelation of globular protein are affected by cosolvent systems present in food systems is critical to understanding their functionality. The expression of these functional attributes depends on the molecular structure and thermal‐mechanical history of the protein, as well as its chemical environment. To improve the design of processing protein‐containing food systems, one must fully understand the thermodynamic, kinetic, and structural impact of cosolvent on globular protein gelation. This review focuses on the impact of weakly interacting neutral cosolvent systems (for example, sugars and polyols) on the gelation of globular proteins. The physicochemical mechanisms by which these cosolvent systems can modulate protein gelation are highlighted from a thermodynamic, kinetic, and structural point of view.
Resistant Starch–A Review
Authors: Sajilata M.G. , Singhal Rekha S. , Kulkarni Pushpa R.
Published: November 2006

The concept of resistant starch (RS) has evoked new interest in the bioavailability of starch and in its use as a source of dietary fiber, particularly in adults. RS is now considered to provide functional properties and find applications in a variety of foods. Types of RS, factors influencing their formation, consequence of such formation, their methods of preparation, their methods of estimation, and health benefits have been briefly discussed in this review.
Use of Volatiles as Indicators of Lipid Oxidation in Muscle Foods
Authors: Ross Carolyn F. , Smith Denise M.
Published: November 2006

Lipid oxidation has long been recognized as a leading cause of quality deterioration in muscle foods and is often the decisive factor in determining food product storage life. Lipid oxidation generates a number of products, including volatile compounds, which are the major contributors to the development of rancid off‐flavors and odors. Over the years, methodologies have been developed to quantify lipid oxidation products in muscle foods. This article reviews the analytical methods that have been used to quantify volatile compounds as indicators of lipid oxidation in muscle foods. The sampling methodologies of distillation/solvent extraction and headspace analysis, and isolation methods associated with gas chromatographic (GC) and high‐performance liquid chromatography (HPLC) analyses are discussed. Within gas chromatographic methodologies, headspace (HS) sampling (static HS, dynamic purge‐and‐trap HS techniques, and solid‐phase microextraction [SPME]) are addressed.
A Critical Review of Milk Fouling in Heat Exchangers
Authors: Bansal Bipan , Chen Xiao Dong
Published: November 2006

Fouling of heat exchangers is a problem in the dairy industry and costs billions of dollars every year. It has been studied extensively by researchers around the world, and a large number of studies are reported in the literature. This review focuses on the mechanisms of milk fouling, investigating the role of protein denaturation and aggregation as well as mass transfer. We also endeavor to review the effect of a number of factors which have been classified into 5 categories: (1) milk quality, (2) operating conditions, (3) type and characteristics of heat exchangers, (4) presence of microorganisms, and (5) transfer of location where fouling takes place. Different aspects have been discussed with the view of possible industrial applications and future direction for research. It may not be possible to alter the properties of milk since they are dependent on the source, collection schedule, season, and many other factors. Lowering the surface temperature and increasing the flow velocity tend to reduce fouling. Reducing the heat transfer surface roughness and wettability is likely to lower the tendency of the proteins to adsorb onto the surface. The use of newer technologies like microwave heating and ohmic heating is gaining momentum because these result in lower fouling; however, further research is required to realize their full potential. The presence of microorganisms creates problem. The situation gets worse when the microorganisms get released into the process stream. The location where fouling takes place is of paramount importance because controlling fouling within the heat exchanger may yield little benefit in case fouling starts taking place elsewhere in the plant.
Do dams increase genetic diversity in brown trout (Salmo trutta)? Microgeographic differentiation in a fragmented river
Authors: Heggenes J. , Røed K. H.
Published: November 2006

Abstract – Local genetic differentiation may potentially arise in recently fragmented populations. Brown trout is a polytypic species exhibiting substantial genetic differentiation, which may evolve in few generations. Movement (semi‐)barriers in rivers may cause fragmentation, isolation and genetic differentiation in fish. In the Måna River (28 km) flowing from the alpine Lake Møsvatn to the boreal Lake Tinnsjø, construction of four hydropower dams during the period 1906–1957 have fragmented the previously (since last Ice Age) continuous wild resident brown trout population. Samples from the two lakes (N = 40) and six sites in the river (N = 30) isolated at different times were analysed at nine microsatellite loci. All populations showed substantial genetic variation (mean number of alleles per locus 5.3–8.9, observed heterozygosity 0.57–0.65 per population, overallFst = 0.032). Pairwise multilocusFstestimates indicated no significant differentiation between populations in the two lakes, and no or little differentiation in the lower river (Fst = 0.0035–0.0091). The microgeographic differentiation among wild resident trout at these sites was less than expected based on similar previous studies. However, results from the upper river, in particular the site immediately below the Lake Møsvatn outlet and dam, indicated isolation (Fst > 0.035). Calculation of genetic distances and assignment tests corroborated these results, as did a significant correlation between years of isolation (since dam construction) andFst. The population structuring is most likely a result of fragmentation by dams, which has increased overall genetic diversity. This increased local differentiation may be caused by natural selection, but more likely by genetic drift in small, recently fragmented populations. Increased local genetic diversity by genetic drift does not justify conservation measures aiming at preserving genetic diversity.
No difference in survival, growth and morphology between offspring of wild‐born, hatchery and hybrid brown trout (Salmo trutta)
Authors: Dahl J. , Pettersson E. , Dannewitz J. , Järvi T. , Löf A‐C.
Published: November 2006

Abstract –  We studied survival, growth and morphological characters in the offspring of native hatchery and wild‐born anadromous brown trout (Salmo trutta) and their hybrids (wild‐born female × hatchery male and wild‐born male × hatchery female) in a 1‐year field experiment. We also conducted laboratory studies where we examined social interactions between the offspring of the same hatchery and wild‐born trout. All offspring were raised in a hatchery and nose tagged before being released into the stream. In total, 1125 individuals were released into the stream (1999) and a total of 614 individuals were recovered (2000). We found no differences in growth and survival between the offspring of hatchery, wild‐born and hybrid trout. Morphology was also similar among groups, where only 38% females and 36% males were classified into the right category, which were only 12% better than random classification. In the laboratory experiment, we compared only the offspring of hatchery and wild‐born trout with respect to growth, dominance, aggressiveness, feeding and activity. We found small differences between the offspring of hatchery and wild‐born fish with respect to growth but this effect was not found in the field experiment. Our result suggests that the offspring of hatchery trout and hybrids between hatchery and wild‐born trout performed equally well to the offspring of wild‐born trout.
The impact of invasive fish on an endemic Cyprinodon species flock (Teleostei) from Laguna Chichancanab, Yucatan, Mexico
Authors: Strecker U.
Published: November 2006

Abstract –  Species that invade a new environment often may lead to population declines of endemic species. Here I document the invasions of an African cichlid (genus Oreochromis) in 1988 and the Mexican Astyanax fasciatus (Characidae) in 1996 into Laguna Chichancanab (Yucatan, Mexico), and the impact on an endemic Cyprinodon species flock and the poeciliid Gambusia sexradiata. After the invasion of Astyanax fasciatus, their relative abundances decreased enormously, most likely caused by predation on the fry. One species, Cyprinodon simus, might have even gone extinct or just occurs in extremely reduced numbers. Furthermore, it was observed that the percentage abundance of the detritivorous Cyprinodon beltrani increased significantly, in contrast to all other Cyprinodon species. This study also revealed that infestation by metacercaria (black spots) of an ectoparasitic trematode and of an endoparasitic nematode increased in the Cyprinodon spp. following the introduction of Oreochromis. Whereas the infestation by trematodes decreased after a period of 6 years, the prevalence and intensity of infestation by nematodes stayed at a high level. In contrast, in G. sexradiata the parasite load remained always very low.
Changing population structure of eels (Anguilla dieffenbachii and A. australis) from southern New Zealand
Authors: Beentjes M. P. , Jellyman D. J. , Kim S. W.
Published: November 2006

Abstract –  Commercial catches of longfin and shortfin eels (Anguilla dieffenbachii and A. australis) were sampled from southern New Zealand in the mid‐1990s to determine the status of the eel population. We compared this with historical information on eel populations to highlight changes in the status, and then investigated the likely causes of these changes. A total of 20,722 longfins and 2366 shortfins were sampled from 216 landings. Longfins dominated catches comprising 53–100% (mean = 90%) of eel numbers. Shortfins were predominantly, but not exclusively, coastal in their distribution, whereas longfins were widely distributed through all reaches sampled. Mean size of shortfin was invariably larger than longfin and for both species generally increased with distance inland, particularly for longfin in the longest rivers. There was no clear geographical separation of longfin sexes although females were more common further inland in the longer rivers. Longfin sex ratio was about 4:1 (male:female), whereas in shortfin it was nearly 100% female. There have been marked changes in the status of the eel population in southern New Zealand over the last 60 years. We suggest that commercial fishing has resulted in a reduction in the size of both species, and for longfins a skewing of the sex ratio toward males – fishing may have favoured differentiation into males as well as the removal of the longer‐lived longfin females. Skewed sex ratio and small size of longfins compared with those of shortfin suggest that this species has been more affected by fishing pressure than shortfins, possibly allowing shortfins to expand their range further inland.
Seasonal variation in marine growth of sea trout,Salmo trutta, in coastal Skagerrak
Authors: Olsen E. M. , Knutsen H. , Simonsen J. H. , Jonsson B. , Knutsen J. A.
Published: November 2006

Abstract – Sea trout (Salmo trutta) originating from small coastal streams can be found at sea throughout the year, in contrast to conspecifics from larger rivers, which typically spend the autumn and winter in fresh water. Such an extended marine stay has been observed in coastal Skagerrak. We studied the seasonal variation in marine growth of Skagerrak sea trout based on scale increment patterns and body lengths of 563 individuals captured at sea. Growth, measured as increased body length, was rapid during summer while there was no evidence for continued growth during autumn and winter. Growth decreased with increasing age of the fish. Our results suggest that coastal Skagerrak is an important feeding area for sea trout during summer, and that an extended marine stay during autumn and winter may have trade‐off benefits other than somatic growth. Alternative benefits might be increased winter survival and decreased migratory costs of juvenile fish.
Murray cod an apex predator in the Murray River, Australia
Authors: Ebner B.
Published: November 2006

Abstract –  To determine if the Murray cod Maccullochella peelii peelii is an apex predator in the lowland rivers of the Murray‐Darling Basin, its feeding ecology was compared with that of the sympatric top predator, golden perch Macquaria ambiguaambigua based on samples supplied by recreational anglers. Diet and prey size were reconstructed from alimentary tract contents of Murray cod (N = 39) and golden perch (N = 52), and their feeding morphology was assessed and included calculation of length–gape relationships and relative gut index. Both species fed principally on fish and decapods although Murray cod was the more piscivorous (frequency of occurrence 44% versus 6%, total number 50% versus 2%, total weight 90.4% versus 16.0%). Based on reconstructions of prey sizes, fishes up to 1 kg in weight were preyed on by Murray cod, distinguishing it from other top predatory fishes in the Murray‐Darling Basin and supporting its classification as an apex predator.
Nocturnal and diurnal feeding by Galaxias auratus, a lentic galaxiid fish
Authors: Stuart‐Smith R. D. , Barmuta L. A. , White R. W. G.
Published: November 2006

Abstract –  We examined the diel feeding pattern, gastric evacuation and daily ration of a lentic, endemic Tasmanian galaxiid fish, Galaxias auratus. Analysis of stomach contents and consumption estimates based on collections of fish every 3 h over three 24‐h periods in summer 2002/2003 revealed that feeding always occurred during both day and night, with no obvious peaks. We also estimated the gastric evacuation rate of G. auratus in a laboratory experiment using the two prey species found to be dominant in stomachs of field‐sampled fish. The relationship was best described by an exponential model, with rate parameters (R) of 0.104 and 0.081 for the evacuation of the amphipod, Austrochiltonia australis, and the cladoceran, Daphnia carinata, at water temperatures of 11.5 and 16.5 °C, respectively. Daily ration of G. auratus in summer was estimated to be approximately 3% (dry body weight) using the models of Elliot & Persson and Eggers. Galaxias auratus appears to be unusual in that its feeding pattern cannot be classified as nocturnal, diurnal or crepuscular, but its gastric evacuation and daily ration estimates are still similar to other comparable Northern Hemisphere freshwater fishes.
Patterns of silver eel (Anguilla anguilla L.) sex ratio in a catchment
Authors: Laffaille P. , Acou A. , Guillouët J. , Mounaix B. , Legault A.
Published: November 2006

Abstract –  Changes in the numbers and size‐class structure of European silver eels, Anguilla anguilla, in the River Frémur (France) were examined over a 9‐year period after installation of downstream eel passes. The number of silver eels migrating downstream peaked in 1999, then decreased strongly and steadily after 2000, reaching relatively low levels. At the same time, a gradual shift in the silver eel sex ratio from a dominance of males (size from 270 to 442 mm, age from 3 to 6 years) to females (size from 366 to 1112 mm, age from 4 to 9 years) was recorded. Possible explanations for the escapement patterns observed are environmental sex determination and the installation of eel passes on the main hydraulic engineering structures in 1992 and 1996.
Standardising multi‐laboratory microsatellite data in Pacific salmon: an historical view of the future
Authors: Moran P. , Teel D. J. , LaHood E. S. , Drake J. , Kalinowski S.
Published: November 2006

Abstract –  For at least 15 years, multiple Pacific Rim Laboratories have cooperated to standardise the collection of Pacific salmon genetic data. For species such as Chinook salmon and chum salmon, allozyme electrophoretic data sets now include hundreds of populations sampled over multiple years throughout the north Pacific. More recently, microsatellite DNA markers have emerged as a new cornerstone of Pacific salmon genetic research. The allozyme experience provides at least two important lessons regarding shared, standardised databases. First, interlaboratory standardisation is sufficiently costly and time consuming that little progress is typically made in the absence of specific fishery management and conservation needs; thus immediate needs will direct future standardisation. Secondly, justified or not, there are significant concerns regarding intellectual propriety and other perceived privileges associated with unpublished genetic data that are shared among laboratories. This article describes challenges to genetic standardisation relative to new research goals, along with specific suggestions for meeting those challenges.
Clinical indications for digital imaging in dento‐alveolar trauma. Part 1: traumatic injuries
Authors: Cohenca Nestor , Simon James H. , Roges Ramon , Morag Yoav , Malfaz Jose Maria
Published: November 2006

Abstract –  Traumatized teeth present a clinical challenge with regard to their diagnosis, treatment plan, and prognosis. Recent developments in imaging systems have enabled clinicians to visualize structural changes effectively. Computed tomography, magnetic resonance imaging and cone beam computed tomography are among the most commonly used systems for dental and maxillofacial surgery. The purpose of this review is to describe the advantages and disadvantages of each technique and the clinical application for dento‐alveolar trauma. Three clinical cases are described to illustrate the potential use of the NewTom 3G for diagnosis and treatment plan of dento‐alveolar traumatic injuries.
Clinical indications for digital imaging in dento‐alveolar trauma. Part 2: root resorption
Authors: Cohenca Nestor , Simon James H. , Mathur Aeshna , Malfaz Jose Maria
Published: November 2006

Abstract –  Common complications of dento‐alveolar trauma are pulp necrosis, pulp canal obliteration, periapical pathosis and root resorption. Different types of root resorption have been identified with traumatic injuries. Repair‐related (surface), infection‐related (inflammatory), ankylosis‐related (osseous replacement) or extraradicular invasive cervical resorption are among the most common. Recent developments in imaging systems have enabled clinicians to visualize structural changes effectively. The diagnosis and three‐dimensional imaging assessment of the resorption is important in order to determine the treatment complexity and expected outcome based on the location and extension of the root defect. This article discusses and illustrates the clinical application of cone beam computed tomography for diagnosis and treatment plan of root resorption. Four clinical cases are presented to illustrate the potential use of the NewTom 3G for root resorption.
Oral and maxillofacial manifestations of familial adenomatous polyposis
Authors: Wijn MA , Keller JJ , Giardiello FM , Brand HS
Published: November 2006

Patients with familial adenomatous polyposis (FAP) develop multiple premalignant colorectal adenomas. Untreated, one or more of these polyps will progress to colorectal carcinoma in middle‐aged adults. Extra‐intestinal manifestations of FAP are frequently observed and this combination has been called Gardner's syndrome. Oral and maxillofacial symptoms of FAP include an increased risk of jaw osteomas, odontomas and supernumerary or unerupted teeth. Early diagnosis of FAP is crucial and may be life saving. As oral signs usually precede gastrointestinal symptoms, the dentist may play an important role in the diagnosis of FAP.
IMP1 interacts with poly(A)‐binding protein (PABP) and the autoregulatory translational control element of PABP‐mRNA through the KH III‐IV domain
Authors: Patel Gopal P. , Bag Jnanankur
Published: November 2006

Repression of poly(A)‐binding protein (PABP) mRNA translation involves the formation of a heterotrimeric ribonucleoprotein complex by the binding of PABP, insulin‐like growth factor II mRNA binding protein‐1 (IMP1) and the unr gene encoded polypeptide (UNR) to the adenine‐rich autoregulatory sequence (ARS) located at the 5′ untranslated region of the PABP‐mRNA. In this report, we have further characterized the interaction between PABP and IMP1 with the ARS at the molecular level. The dissociation constants of PABP and IMP1 for binding to the ARS RNA were determined to be 2.3 nm and 5.9 nm, respectively. Both PABP and IMP1 interact with each other, regardless of the presence of the ARS, through the conserved C‐terminal PABP‐C and K‐homology (KH) III‐IV domains, respectively. Interaction of PABP with the ARS requires at least three out of its four RNA‐binding domains, whereas KH III‐IV domain of IMP1 is necessary and sufficient for binding to the ARS. In addition, the strongest binding site for both PABP and IMP1 on the ARS was determined to be within the 22 nucleotide‐long CCCAAAAAAAUUUACAAAAAA sequence located at the 3′ end of the ARS. Results of our analysis suggest that both protein·protein and protein·RNA interactions are involved in forming a stable ribonucleoprotein complex at the ARS of PABP mRNA.
Phytochelatin–cadmium–sulfide high‐molecular‐mass complexes of Euglena gracilis
Authors: Mendoza‐Cózatl David G. , Rodríguez‐Zavala José S. , Rodríguez‐Enríquez Sara , Mendoza‐Hernandez Guillermo , Briones‐Gallardo Roberto , Moreno‐Sánchez Rafael
Published: November 2006

High‐molecular‐mass PC complexes (PC‐HMWCs) constituted by phytochelatins (PCs), cadmium and sulfide are synthesized by several organisms after exposure to cadmium. In this study, PC‐HMWCs were isolated from photoheterotrophic Euglena gracilis and purified to homogeneity, resulting in compounds of molecular mass 50–380 kDa depending on the CdCl2 and sulfate concentrations in the culture medium. In contrast with plants and some yeasts, PC‐HMWCs from E. gracilis mainly comprise (57–75%) monothiol molecules (Cys, γ‐glutamylcysteine, GSH) and, to a lesser extent (25–43%), PCs. A similar acid‐soluble thiol compound composition was found in whole cell extracts. The –SH/Cd2+and S2–/Cd2+ ratios found in purified PC‐HMWCs were 1.5 and 1.8, respectively; the (–SH + S2–)/Cd2+ ratio was 3.2. PC‐HMWCs of molecular mass 60 and 100 kDa were also localized inside Percoll‐purified chloroplasts, in which cadmium and PCs were mainly compartmentalized. Cadmium and sulfur‐rich clusters with similar sulfur/cadmium stoichiometries to those of the purified PC‐HMWCs were detected in the chloroplast and throughout the cell by energy dispersive microanalysis and atomic resolution electron microscopy. The presence of PC‐HMWCs in primitive photosynthetic eukaryotes such as the protist, E. gracilis, suggests that their function as the final cadmium‐storage‐inactivation process is widespread. Their particular intracellular localization suggests that chloroplasts may play a major role in the cadmium‐resistance mechanism in organisms lacking a plant‐like vacuole.
Cold stress defense in the freshwater sponge Lubomirskia baicalensis
Authors: Müller Werner E. G. , Belikov Sergey I. , Kaluzhnaya Oxana V. , Perović‐Ottstadt Sanja , Fattorusso Ernesto , Ushijima Hiroshi , Krasko Anatoli , Schröder Heinz C.
Published: November 2006

The endemic freshwater sponge Lubomirskia baicalensis lives in Lake Baikal in winter (samples from March have been studied) under complete ice cover at near 0°C, and in summer in open water at 17 °C (September). In March, specimens show high metabolic activity as reflected by the production of gametes. L. baicalensis lives in symbiosis with green dinoflagellates, which are related to Gymnodinium sanguineum. Here we show that these dinoflagellates produce the toxin okadaic acid (OA), which is present as a free molecule as well as in a protein‐bound state. In metazoans OA inhibits both protein phosphatase‐2A and protein phosphatase‐1 (PP1). Only cDNA corresponding to PP1 could be identified in L. baicalensis and subsequently isolated from a L. baicalensis cDNA library. The deduced polypeptide has a molecular mass of 36 802 Da and shares the characteristic domains known from other protein phosphatases. As determined by western blot analysis, the relative amount of PP1 is almost the same in March (under ice) and September (summer). PP1 is not inhibited by low OA concentrations (100 nm); concentrations above 300 nm are required for inhibition. A sponge cell culture system (primmorphs) was used to show that at low temperatures (4 °C) expression of hsp70 is strongly induced and hsp70 synthesis is augmented after incubation with 100 nm OA to levels measured at 17 °C. In the enriched extract, PP1 activity at 4 °C is close to that measured at 17 °C. Immunoabsorption experiments revealed that hsp70 contributes to the high protein phosphatase activity at 4 °C. From these data we conclude that the toxin OA is required for the expression of hsp70 at low temperature, and therefore contributes to the cold resistance of the sponge.