bluuebunny/crossref_metadata_2025 huggingface dataset:
SHELL‐BORING WORMS (SPIONIDAE: Polychaeta) INFECTING CULTIVATED BIVALVE MOLLUSCS IN AUSTRALIA
Authors: Skeel M. E.
Published: August 2010

The New South Wales rock oyster (Saccostrea cucullata), the edible mussel (Mytilus edulis), the introduced Pacific oyster (Crassostrea gigas) and the scallop (Placopecten meridionalis) are cultivated in Australia. Their shells harbor four species of spionid polychaetes: Polydora websteri, Polydora haswelli, Polydora hoplura and Boccardia chilensis. P. websteri is found in all four molluscs and causes the most damage, especially to the New South Wales rock oyster, by forming irritating and often fatal mud blisters between the shell and mantle.

All four mudworm species have internal fertilization and rear their young in egg sacks within the blister. In some species, a few eggs develop in each sack, the larvae feed on the remaining eggs and a few well‐developed larvae are released. In others, all eggs develop within each sack, there is no extra food for the larvae and many immature larvae are soon released. The survival values of these reproductive strategies are discussed.
GROWTH RATES OF Macrobrachium rosenbergii IN SOUTH FLORIDA. 2. GROWTH OF INTRASPECIFIC HYBRIDS
Authors: Dobkin S. , Bailey D. J.
Published: August 2010

Growth rates for hybrid Macrobrachium rosenbergii (Thai x Malaysian X Malaysian and Thai x Malaysian X Thai x Malaysian) raised in south Florida are presented. The second generation Thai x Malaysian hybrids had a mean weight of 31.8 g at 210 days of age. The back‐crossed hybrids had a mean weight of 28.6 g at 187 days of age and 33.8 g at 247 days. The growth of both of these hybrids was greater than that of our most successful Malaysian animals which had a mean weight of 19.5 g after 198 days.
INHIBITION OF GROWTH OF Macrobrachium rosenbergii BY CALCIUM CARBONATE WATER HARDNESS
Authors: Cripps M. C. , Nakamura R. M.
Published: August 2010

Slow growth of adult Macrobrachium rosenbergii in grow‐out ponds having calcium water hardness of 305 to 638 mg/liter calcium carbonate was observed, as was frequent encrustation with Bryozoa sp. and Epistylus sp.

Adult M. rosenbergii of ages 5, 13, and 14 months were held in calcium carbonate solutions of from 0.65 to 5.00 mM/liter Ca (65 to 500 mg/liter CaCO3) for up to 90 days. Average daily weight gain was found to be five times greater in the lowest calcium concentration for 5‐month‐old prawns compared with the high calcium group. A seven‐fold difference was found in standard length gains. Lower differences were found for 13 and 14‐month‐old prawns, and a lengthening of the molt cycle in high calcium water was seen.

Differences were also seen in post‐molt hemolymph calcium, inorganic phosphorus, and refractive index but not sodium, potassium, chloride, or osmolarity.
TWENTY YEARS OF FRUSTRATIONS IN MARICULTURE
Authors: Loring R. H.
Published: August 2010

Aquacultural Research Corporation has been active in commercial molluscan mariculture for 20 years. The paper reviews frustrations and rewards from the personal point of view of the author and includes: factors leading to the selection of hard clams and scallops as principal products, difficulties encountered in algal production and hatchery operations, and field problems including regulation, predation, poaching, storm damage, mass handling of product, etc. Immediate and long‐term plans are discussed.
THE COMMERCIAL PRODUCTION OF OYSTERS IN AN INTENSIVE RACEWAY SYSTEM
Authors: Scura Edward D. , Kuljis Andrew M. , York Richard H. , LeGoff Robert S.
Published: August 2010

Aquatic Farms, located on windward Oahu, Hawaii, is engaged in the commercial production of oysters in a partially recirculated, intensive raceway system. Selected phytoplankton species are cultured in 0.2‐ha earthen ponds and fed to the oysters by a gravity‐fed overflow piping system. The bivalve culture system and its operation are described. Oysters grown in this manner are currently reaching a market size of 55 g in 10 months (from 2 mm seed). A shorter grow‐out period is suggested by recent developments in the operation. The efficiency of this system in converting phytoplankton to oysters is discussed.
EFFECTS OF PROTEIN‐ENERGY RATIOS ON GROWTH OF AMERICAN LOBSTERS (Homarus americanus)
Authors: Gallagher Margie Lee , Bayer Robert C. , Leavitt Dale F. , Rittenburg James H.
Published: August 2010

Pre‐molt adult lobsters in stage D0 to D1 were fed undefined artificial diets with protein‐energy ratios of 0.07 to 0.15 in which caloric densities remained constant or varied from 2.34 to 4.48 kcal/g. Growth was measured by change in wet weight in air. There were no significant differences between diets after 8 weeks. When similar diets were fed to post‐molt adult lobsters (stages A1‐A2), there was a significant increase in weight of lobsters fed diets with protein‐energy ratio of 0.07 and caloric density of 2.34 kcal/g as compared to pre‐molt lobsters, indicating that stage of molt significantly affects dietary response. Similar results were also found within juvenile feeding trials.
STUDIES ON COMPOUNDED DIETS FOR Penaeus kerathurus SHRIMP
Authors: Fernández Ramón , Puchal Francisco
Published: August 2010

The apparent large differences in nutritive requirements reported for different shrimp species precludes extrapolation of available data from one species to another. This fact and the general scarcity of knowledge about crustacean dietary requirements presents a formidable problem to the nutritionist when beginning with a new shrimp candidate.

The species used in these experiments was the Penaeus kerathurus, a shrimp native to the eastern Atlantic and Mediterranean coastline. A total of 1,000 postlarvae were used in six experimental trials, concerned with the acceptability of formulated rations and the effectiveness of different protein sources, and considering previous techniques carried out in this field. Other aspects examined were the influence of natural food (mussel mantle and gonad) as a complement to the artificial diet, and the presence in it of an unidentified growth factor(s).

From the results obtained, the acceptability of the compounded diets stands out. However, these diets failed to support greater than 50–55% of the fresh mussel diet growth in all experiments. This observation and the strong reduction in nutritional value of the fresh food by processing are related by two possible explanations: first, the rapid leaching of water‐soluble nutrients, and second, the idea of a labile unknown metabolite essential for the growth of these animals.
TRACE CONTAMINANT ACCUMULATION BY ORGANISMS GROWN IN A WASTE RECYCLING AQUACULTURE SYSTEM1
Authors: Mann Roger , Ryther John H.
Published: August 2010

Three species of bivalve mollusc Crassostrea gigas (Thunberg), Ostrea edulis L., Tapes philippinarum (Adams and Reeve), one species of crustacean, Homarus americanus, and one species of macroscopic algae Gracilariopsis sjostedtii were grown in a pilot‐scale marine waste recycling aquaculture system for a period of 18 months. Organisms were exposed to 14 different regimes of food chain enrichment using either secondary treated sewage effluent, a mixture of inorganic nitrogen and phosphorus compounds free of contaminants, or a combination of both to simulate “growth” and “depuration” periods in an on‐site application. Throughout the study organisms were sacrificed at monthly intervals and assayed for 7 trace metals (Cd, Cr, Cu, Hg, Ni, Pb, Zn). Sewage effluent used for food chain enrichment was assayed for the same suite of metals three times per week. No significant differences were evident between organisms cultured in the contaminant‐free and effluent enriched regimes. Shellfish trace metal contents were consistently below FDA “alert” levels. H. americanus trace metal levels were within acceptable standards for human consumption. Trace metal levels in G. sjostedtii were comparable with those recorded for natural populations of macrophytes. Data suggest that trace metals constitute a minimal public health problem in organisms cultured for human consumption in waste recycling systems; however, problems related to organic residues and viruses have yet to be fully evaluated.
POTENTIAL FOR COMMUNAL REARING OF THE NEPHROPID LOBSTERS (Homarus spp.)1
Authors: Carlberg James M. , Van Olst Jon C. , Ford Richard F.
Published: August 2010

A series of experiments was conducted with American lobsters (Homarus americanus) and European lobsters (Homarus gammarus) to develop methods to reduce cannibalism among communally‐reared juveniles. The primary factors studied were substrate type, stocking density and photoperiod. Other conditions investigated were the effects of different water Temperatures, food type, segregating large individuals and claw immobilization. Preliminary studies also were conducted on the effects of shelter density, feeding level and tank area. These studies showed that by the use of vertical substrates, segregating techniques and immobilization of claws, carrying capacity can be increased considerably.
GENETIC DIVERGENCE AND BIOGEOGRAPHY OF NATURAL POPULATIONS OF Macrobrachium rosenbergii
Authors: Hedgecock D. , Stelmach D. J. , Nelson K. , Lindenfelser M. E. , Malecha S. R.
Published: August 2010

Electrophoretic studies of gene‐enzyme variation in natural populations of the freshwater prawn (Macrobrachium rosenbergii) are undertaken to quantify the amount of racial divergence among geographically separated natural populations. A total of 440 individuals from 11 localities spread from Sri Lanka to New Guinea, Palau and the Hawaiian cultured stocks are analyzed for genetic variation in as many as 31 electrophoretically detectable proteins. Within‐population variability is relatively low: the average proportion of heterozygous loci in any given individual is 2.8% and the average proportion of polymorphic geneenzymes per population is 14%.

Population differences are summarized by proportions of loci having no genotypes in common between populations (“% diagnostic loci”). Prawn populations from Australia, New Guinea, the Philippines, and Palau are well differentiated from the rest, with genetically fixed enzyme differences at over 20% of the gene‐enzyme systems. That this major discontinuity in the gene pool of M. rosenbergii corresponds to the well recognized zoogeographic boundary known as Wallace' Line suggests that insular distribution has contributed to genetic divergence.

One or 2 fixed or nearly fixed differences were also found among populations within the 2 major races east and west of Wallace' Line. These results support the hypothesis that this species has undergone substantial racial divergence over its range and that natural populations represent a tremendously diverse genetic resource for freshwater prawn aquaculture.
THE STATUS OF MACROBRACHIUM FARMING IN THAILAND
Authors: Singholka Somsuk , New Michael B. , Vorasayan Paiboon
Published: August 2010

The farming of Macrobrachium rosenbergii is widespread in Thailand. Currently over 200 farms are being supplied with juveniles from the main government hatchery. Many small “backyard” hatcheries exist and the number of large commercial hatcheries and production farms is increasing. Over half the Thai provinces have Macrobrachium farms but the species is still being imported to satisfy local demand. Production of farmed freshwater prawns is estimated at 245 tons per year in 1979. Retail market values of US $10.00–12.50/kg, whole, shell‐on give the industry a scale of nearly US $2.8 million annually. Unsatisfied local demand, together with optimal rearing conditions and export potential, promises to stimulate further significant development in this industry in Thailand.
WATER CIRCULATION FOR POND AERATION AND ENERGY CONSERVATION
Authors: Busch Charles D.
Published: August 2010

Oxygen transfer theory has shown that use of mechanical aerators may decrease instead of increase pond water oxygen levels. Photosynthetic production of oxygen can result in supersaturated concentrations while the maximum level attainable using mechanical aeration is saturation. Based on these observations a new paddlewheel has been designed and tested to provide stirring of pond waters instead of splashing, bubbling or spraying. The tests demonstrated that daytime circulation can serve to increase dissolved oxygen content in the deeper portions of the pond during the following night. The concept of aeration through pond circulation requires only a fraction of the power associated with most existing aerators.
SMALL‐SCALE MASS CULTURE OF Daphnia magna Straus
Authors: Rees John T. , Oldfather Joan M.
Published: August 2010

Daphnia magna Straus 1820 was reared on a defined medium in 4‐liter flasks under controlled conditions of light, temperature and species of algal food. Adult D. magna were found to be tolerant of high levels of ammonia, up to 108 μM, at high pH (>10), although parthenogenic reproduction may be inhibited at these high levels. Scenedesmus quadricauda and Ankistrodesmus sp. were found to be satisfactory food sources. Densities of greater than one animal per ml in culture were attained utilizing Ankistrodesmus sp. as a food source at a pH of 7.7. Maintenance of pH at around 7–8 appears to be important to successful D. magna culture.
THE MASS CULTURE OF THE ROTIFER, Brachionus plicatilis, FOR USE AS FOODSTUFF IN AQUACULTURE1
Authors: Fontaine Clark T. , Revera Dickie B.
Published: August 2010

Discussed is the mass culture of rotifers at the National Marine Fisheries Service, Southeast Fisheries Center, Galveston Laboratory, Galveston, Texas, in the Galveston penaeid shrimp hatchery system and for use in marine fish larval culture. Techniques are described for: 1) harvesting rotifer tanks by “skimming” the surface of the water; 2) concentrating the harvested rotifers by shocking with deionized water; and 3) storing large quantities of rotifers to be used as foodstuff by conventional freezing methods. Also discussed is a technique being developed whereby the rotifer is used as a carrier medium for various nutrients.
RELEASE OF HATCHERY‐REARED BAY SCALLOPS (Argopecten irradians) ONTO A SHALLOW COASTAL BOTTOM IN WATERFORD, CONNECTICUT
Authors: Morgan D. E. , Goodsell J. , Matthiessen G. C. , Garey J. , Jacobson P.
Published: August 2010

Survival and growth of hatchery‐reared bay scallops (Argopecten irradians) transferred to a shallow coastal area in outer Jordan Cove, Connecticut, were monitored by SCUBA during the summer and fall of 1979. In all, 47,000 bay scallops were released over 4 sequential seedings. Based on slopes derived from linear regression models the time to 50% loss of bay scallops from the release areas was less than one day for juveniles ≤22 mm and ≥6 days for scallops ≥24 mm. Significant (α = 0.05) reductions in the rate of loss occurred as scallop size increased at release. Scallops released with shell heights >45 mm had the lowest rates of loss. Both predation and dispersion effected these loss rates. Predation of scallops was attributed to the following benthic invertebrates: 6 species of crabs (Cancer borealis, Cancer irroratus, Carcinus maenus, Callinectes sapidus, Pagurus pollicarpus, Pagurus longicarpus), lobsters (Homarus americanus), 2 species of oyster drills (Urosalpinx cinerea and Eupleura caudata) and sea stars (Asterias forbesi). These predators contributed to most of the losses of bay scallops ≤22 mm and at least 20–50% of the losses in scallops ≥24 mm. Dispersion consisted of a northwest drift of scallops across the field study areas, which was probably enhanced by current patterns. Growth of bay scallops from October 3–24 was 0.26 mm/day and the rate of growth slowed as the water temperature dropped below 15°C.
SEASONAL VARIATION IN THE CONDITION OF RAFT‐CULTIVATED MUSSELS (Mytilus edulis L.)
Authors: Lutz Richard A. , Incze Lewis S. , Porter Barnaby , Stotz John K.
Published: August 2010

The condition indices (wet meat volume and dry meat weight) of raft‐cultivated mussels from a north temperate estuary showed similar seasonal variations over a 3‐year period. Two periods of peak condition (one occurring in late spring and the other in the fall and early winter) were apparent during all 3 years of the study. A rapid decline in condition was observed at the end of May during each year, reflecting the period of spawning. A second decrease in condition was observed during August of each year, suggesting that a late summer spawning may be a general feature of the studied population. Although the precise timing and amplitude of the peaks in condition varied somewhat from year to year, high meat yields can be anticipated from early April through mid‐May and again from September through early winter in the environment studied. Results obtained in this study should provide useful guidelines for optimizing the productivity of commercial culture operations.
SOME FACTORS AFFECTING THE APPEARANCE OF EXTRACELLULAR HEMOLYSIN AND PROTEASE IN BATCH CULTURES OF THE OPPORTUNISTIC PATHOGEN Aeromonas hydrophila
Authors: Thompson Barbara T. , Riddle Lavon M. , Culley Dudley D. , Amborski Robert L.
Published: August 2010

Aeromnas hydrophila, an opportunistic pathogen identified to be the causative agent of disease in many ectothermic animals, was grown in batch culture in a variety of complex and defined media to determine the effects of changes in medium composition on the production of extracellular hemolytic and proteolytic activities. A lag period of 24 hours was seen in cultures in defined media. This lag period was eliminated by adding yeast extract to the medium but was not eliminated by the addition of any of a group of vitamins or major energy and carbon sources. The effects of a group of trace minerals were studied, and it was found that zinc stimulated production of hemolysin, and that iron increased the growth yield and depressed both protease and hemolysin production. Although individual amino acids stimulated or retarded growth, changes in the amino acid composition of the medium did not greatly alter hemolysin production, in the absence of added zinc. In the presence of magnesium and zinc some amino acids stimulated hemolysin production.

In view of the effects of the trace metals on toxin production in vitro, it is possible that nutritional immunity involving these metals could be a valuable exploitable defense mechanism in attempts to control Aeromonas‐caused disease.
STARVATION EFFECT ON METABOLISM OF Penaeus japonicus
Authors: Cuzon G. , Cahu C. , Aldrin J. F. , Messager J. L. , Stéphan G. , Mével M.
Published: August 2010

Changes in biochemical composition during starvation were studied in the shrimp Penaeus japonicus (Bate). Results indicate a progressive suppression of metabolism compared with normally fed shrimp. There is no significant decrease in the body weight over a period of 4 weeks starvation. Study of biochemical changes during starvation showed that P. japonicus consumed primarily carbohydrates, then lipids to meet its energy requirement; proteins were utilized significantly only during the final week of starvation. The evolution of the digestive gland index is measured together with hemolymph concentrations (glucose and total proteins) in order to interpret the physiological mechanisms of resistance to starvation.
HISTOLOGICAL OBSERVATIONS OF THE HEPATOPANCREAS IN JUVENILE LOBSTERS SUBJECTED TO DIETARY STRESS
Authors: Rosemark R. , Bowser P. R. , Baum N.
Published: August 2010

A study was designed to evaluate the hepatopancreas of the American lobster (Homarus americanus) as a potential indicator organ for early dietary stress. Seventy‐five 7th stage lobsters were divided into 3 groups. Group 1 was fed live brine shrimp (Artemia salina), group 2 was fed a sub‐optimal artificial diet (M4), and group 3 was starved. Three animals from each group were sacrificed at days 2, 4, 8, 12, 16, 22 and 29. The hepatopancreas from each animal was examined grossly and then prepared for histological evaluation. A general atrophy of especially the absorptive and secretory cells in the hepatopancreas of the starved animals was noticed as early as 4 days. In the hepatopancreas of the M4 fed juveniles, a progressive increase in the number of pycnotic nuclei and necrosis was evident by 8 days. Evidence of amyloid and ceroid were also observed. This ability to detect early cellular differences due to dietary deficiencies can be an important procedure for analyzing nutritional data.
MATURATION AND REPRODUCTION OF Penaeus setiferus IN CAPTIVITY
Authors: Lawrence A. L. , Akamine Y. , Middleditch B. S. , Chamberlain G. , Hutchins D.
Published: August 2010

Recently, the maturation and spawning of Penaeus setiferus in captivity was reported. However, none of the spawned eggs hatched. This paper reports the maturation and spawning of Penaeus setiferus in captivity with 0 to 75% of the spawned eggs hatching. The experiments were performed in 4.9 m diameter circular tanks at Marifarms, Inc. facility in Panama City, Florida. Each circular tank contained 70 to 80 animals with 1:1 female to male ratio. All females within 2 tanks were unilaterally ablated and all females in a third tank were unablated. The diet consisted of a 1:1:1 ratio of prepared dried feed or oysters, squid, and polychaete worms. The animals were fed 3% of their body weight each day. The feeding times were 0800, 1130 and 1500 hours. A natural light regimen was used with a salinity variation of 24 to 29 ppt and a temperature range of 27 to 31°C. Only unilaterally ablated females produced fertile eggs. Repeated spawns produced approximately 1,565,000 nauplii over a period of 30 days. Three groups totaling 865,000 nauplii were raised to 17‐day‐old postlarvae with an average survival of 65% at the Marifarms, Inc. hatchery. Thirty‐six thousand of these postlarvae were stocked in an integrated 3‐pond system at the Texas A&M facility in Corpus Christi, Texas. The animals grew to an average size of 8.1 g with 61.5% survival after 117 days in the pond. Thus, for the first time, laboratory maturation, repeated spawning, successful hatching, larval development and juvenile production was achieved for Penaeus setiferus.
THE IMPORTANCE OF SELECTING FOR SURVIVORSHIP IN GENETIC YIELD IMPROVEMENT PROGRAMS IN CRUSTACEAN AQUACULTURE
Authors: Doyle Roger W. , Hunte Wayne
Published: August 2010

Mortality between “seeding” and harvest can cause serious loss of production in crustacean aquaculture. When a species is brought under cultivation for its complete life cycle, genetic changes inevitably result from natural selection in the controlled environment (domestication selection). Such changes can, in a properly designed program, lead to a reduction in the variability that is the source of much of the economic loss. Domestication selection resulted in a two‐fold increase in productivity in a model aquaculture program which involved cultivating the estuarine amphipod Gammarus lawrencianus in the laboratory. Approximately 75% of this gain was due to increased survivorship, the remainder to increased growth rate. Domestication selection will be beneficial in any crustacean with similar genetic relationships among the quantitative traits which determine yield. In aquaculture programs designed with genetic stock improvement in mind, it may be advantageous to reduce mortality by domestication selection before beginning conventional selection or inbreeding for individual traits such as growth rate. If this is not done, conventional programs may be counter‐productive because of their concentrating effect on “unfit” genes which are present in the population. Domestication can be accomplished by systematic feedback of progeny from the outgrowth ponds into the broodstock, and/or selection for lifespan, and/or selection for survivorship on a family basis.
OBSERVATIONS ON THE REPRODUCTIVE STATE OF MILKFISH POPULATIONS (Chanos chanos) FROM HYPERSALINE PONDS ON CHRISTMAS ISLAND (PACIFIC OCEAN)
Authors: Crear David
Published: August 2010

Milkfish (Chanos chanos) populations spawned in landlocked, hypersaline ponds on Christmas Island during 1976 and 1977. Specimens collected from one isolated population showed a mean gonadosomatic index (GSI) of 3.6. Virtually all males from this population were running ripe. Several mature females with GSI values ranging from approximately 15 to 25 were captured. One was running ripe. The high GSI maintained by this population and observations of running ripe fish and fingerlings in other ponds with salinities ranging from 60 to 130 ppt indicated that the milkfish spawn on a year‐round basis in these landlocked lagoons. Milkfish in hypersaline ponds matured sexually in spite of severely stunted growth. Mature fish from several hypersaline ponds (normal salinity 100–130 ppt) had mean weights of only one kilogram. Several adult milkfish were observed at salinities up to 158 ppt. Reproductive readiness in the fish appeared to be determined by the interaction of diet and salinity with the effect of diet prevailing. Inclusion of the brine shrimp (Artemia salina) in the diet of the milkfish was the strongest stimulant to the production of reproductive tissue. Stunted populations of milkfish on Christmas Island offer an attractive opportunity to study the reproductive physiology of the species due to the relative ease in handling the smaller fish.
Racial Profiling and Traffic Stops: An Examination of Research Approaches and Findings in the War on Drugs
Authors: Glover Karen S. , Penalosa Miguel , Schlarmann Aaron
Published: August 2010

This article is a review of some of the main research approaches to understanding racial profiling as it manifests in the traffic stop. It orients the emergence of racial profiling as a product of the war on drugs philosophy guiding law enforcement in the late 20th century and discusses how the contemporary nature of racial profiling has origins in a long history of racialized policing in the United States. Theoretical and methodological approaches to the issue, particularly from mainstream criminologists, focus on quantitative assessment of exposure to law enforcement agents and rational choice‐based arguments that it makes sense to target certain groups based on the hue of the criminal justice system. More critical approaches examined within complicate this notion by contextualizing racial profiling in contemporary times as a mere manifestation of historical efforts by the state to marginalize communities of color.
Optimization Based Geometric Modeling of Nano/Micro Scale Ion Milling of Organic Materials for Multidimensional Bioimaging
Authors: Fu Jing , Joshi Sanjay
Published: August 2010

Focused ion beam (FIB) instruments have recently started to be seen in applications to organic materials such as polymers and biological samples. FIB provides a novel tool for sectioning biological samples for electron microscope based imaging or microfabrication with environment friendly materials. The modeling of nano/micro scale geometry accurately sculptured by FIB milling is crucial for generating the milling plan and process control, and for computer simulation based prediction and visualization of the milled geometry. However, modeling of the milled geometry on compound materials, especially for high aspect ratio feature, is still difficult due to the complexity of target material, as well as multiple physical and chemical interactions involved. In this study, a comprehensive model of ion milling with organic targets is presented to address the challenges in using a simulation based approach. At each discrete point of the milled front, the depth is the dynamic result of aggregate interactions from neighboring areas, including physical sputtering and chemical reactions. Instead of determining the exact interactions, the parameters of the proposed model are estimated by studying a number of preliminary milling results followed by a nonlinear optimization model. This platform has been validated by milling different features on water ice in a cryogenic environment, and the simulation and experiment results show great consistency. With the proliferation of nanotechnology in biomedical and biomaterial domains, the proposed approach is expected to be a flexible tool for various applications involving novel and heterogeneous biological targets.
A Distinct Catabolic to Anabolic Threshold Due to Single-Cell Static Nanomechanical Stimulation in a Cartilage Biokinetics Model
Authors: Saha Asit K. , Kohles Sean S.
Published: August 2010

Understanding physicochemical interactions during biokinetic regulation will be critical for the creation of relevant nanotechnology supporting cellular and molecular engineering. The impact of nanoscale influences in medicine and biology can be explored in detail through mathematical models as an in silico testbed. In a recent single-cell biomechanical analysis, the cytoskeletal strain response due to fluid-induced stresses was characterized (Wilson, Z. D., and Kohles, S. S., 2010, “Two-Dimensional Modeling of Nanomechanical Strains in Healthy and Diseased Single-Cells During Microfluidic Stress Applications,” J. Nanotech. Eng. Med., 1(2), p. 021005). Results described a microfluidic environment having controlled nanometer and piconewton resolution for explorations of multiscale mechanobiology. In the present study, we constructed a mathematical model exploring the nanoscale biomolecular response to that controlled microenvironment. We introduce mechanical stimuli and scaling factor terms as specific input values for regulating a cartilage molecule synthesis. Iterative model results for this initial multiscale static load application have identified a transition threshold load level from which the mechanical input causes a shift from a catabolic state to an anabolic state. Modeled molecule homeostatic levels appear to be dependent upon the mechanical stimulus as reflected experimentally. This work provides a specific mathematical framework from which to explore biokinetic regulation. Further incorporation of nanomechanical stresses and strains into biokinetic models will ultimately lead to refined mechanotransduction relationships at the cellular and molecular levels.
Evaluation of the Mechanical Properties of CNT Based Composites Using Hexagonal RVE
Authors: Joshi Unnati A. , Joshi Preeti , Harsha S. P. , Sharma Satish C.
Published: August 2010

Carbon nanotubes (CNTs) possess extremely high stiffness, strength, and resilience, and may provide ultimate reinforcing materials for the development of nanocomposites. In this paper, the effective material properties of CNT-based composites are evaluated based on the continuum mechanics using a hexagonal representative volume element (RVE). Numerical equations are used to extract the effective material properties from numerical solutions for the hexagonal RVEs under axial loading case. An extended rule of mixtures for estimating effective Young’s modulus in the axial direction of the RVE is applied. It has been observed that the addition of the CNTs in a matrix at volume fractions of only about 3.6%, the stiffness of the composite is increased by 33% for long CNT at Et/Em=10, whereas not much improvement in stiffness has been noticed in the case of short CNTS at Et/Em=10. Effectiveness of composites is evaluated in terms of various dimensions such as thickness, diameter, and length of CNT. These results suggest that short CNTs in a matrix may not be as effective as long CNTs in reinforcing a composite. The simulation results are consistent with the experimental ones reported in literature. Also, the comparative evaluation of all three types of RVEs is presented here.
Nanotechnology in Neurosurgery
Authors: Collins Kelly L. , Orringer Daniel A. , Patil Parag G.
Published: August 2010

Clinical neurology and neurosurgery are two fields that face some of the most challenging and exciting problems remaining in medicine. Brain tumors, paralysis after trauma or stroke, and neurodegerative diseases are some of the many disorders for which effective therapies remain elusive. Nanotechnology seems poised to offer promising new solutions to some of these difficult problems. The latest advances in materials engineered at the nanoscale for applications relevant to the clinical neurosciences, such as medical imaging, nanotherapies for neurologic disease, nerve tissue engineering, and nanotechnological contributions to neuroelectrodes and brain-machine interface technology are reviewed. The primary classes of materials discussed include superparamagnetic iron oxide nanoparticles, gold nanoparticles, liposomes, carbon fullerenes, and carbon nanotubes. The potential of the field and the challenges that must be overcome for the current technology to become available clinically are highlighted.
Ordered Au Nanodisk and Nanohole Arrays: Fabrication and Applications
Authors: Zheng Yue Bing , Juluri Bala Krishna , Kiraly Brian , Huang Tony Jun
Published: August 2010

We have utilized nanosphere lithography (NSL) to fabricate ordered Au nanodisk and nanohole arrays on substrates and have studied the localized surface plasmon resonance (LSPR) of the arrays. Through these investigations, we demonstrate that the angle-dependent behavior of the LSPR in the Au nanodisk arrays enables real-time observation of exciton-plasmon couplings. In addition, we show that the NSL-fabricated Au nanohole arrays can be applied as templates for patterning micro-/nanoparticles under capillary force. The unique structural and plasmonic characteristics of the Au nanodisk and nanohole arrays, as well as the low-cost and high-throughput NSL-based nanofabrication technique, render these arrays excellent platforms for numerous engineering applications.
Entanglement, which-way measurements, and a quantum erasure
Authors: Ferrari Christian , Braunecker Bernd
Published: August 2010

We present a didactical approach to the which-way experiment and the counterintuitive effect of the quantum erasure for one-particle quantum interferences. The fundamental concept of entanglement plays a central role and highlights the complementarity between quantum interference and knowledge of which path is followed by the particle.
The photon picture of radiation transport
Authors: Rosato J.
Published: August 2010

The photon picture of radiation transport is examined. Because the photon has no mass and spin one, a position operator for a photon particle cannot be defined properly. This lack leads to ambiguity if the radiative transfer equation is associated with a quantum transport equation for photons. The issue of photon nonlocalizability is discussed and illustrated through a wavefunction-based approach. It is next shown that the phase space formalism due to Wigner provides a suitable framework for a proper derivation of a photon transport equation from first principles.
Steering quantum states toward classical Bohr-like orbits
Authors: Dunning F. B. , Reinhold C. O. , Yoshida S. , Burgdörfer J.
Published: August 2010

We describe how, almost 100 years after the introduction of the Bohr model of the atom, it is now possible using pulsed electric fields to create localized wavepackets in high n (n≈300) Rydberg atoms that travel in near-circular Bohr-like orbits mimicking the behavior of a classical electron. The protocols employed are explained with the aid of quantum and classical dynamics. Although many aspects of the underlying behavior can be described using classical arguments, purely quantum effects such as revivals can be seen even for n≈300.
Abrogating Angiogenesis Just Got EZier
Authors: Alumkal Joshi
Published: August 2010

The EZH2 histone methyltransferase regulates tumor angiogenesis and can be targeted to tumors with small interfering RNAs.
Another Step Toward a Cure for Type 1 Diabetes Mellitus
Authors: Bentley-Lewis Rhonda
Published: August 2010

A drug currently used to prevent organ transplant rejection can avert type 1 diabetes in rats while maintaining immune system activation.
Endovascular rescue of a misshapen intracranial stent: report of two cases
Authors: Chen Michael , Goldstein-Smith Lindsay
Published: August 2010

Inadvertent deformation and displacement of a fully deployed closed-cell intracranial nitinol stent may occur with manipulation of other devices through or beyond them. Such displaced and deformed stents may obstruct the lumen, risking formation of thromboemboli, and/or fail to no function as a scaffold to assist with coil embolization. We review two such cases whereby an Alligator retrieval device (ARD) (ev3, Irvine, California, USA) was used to salvage a deployed misshapen intracranial stent.
Critical care management in acute ischemic stroke
Authors: De Georgia Michael , Patel Vishal
Published: August 2010

Neurocritical care has evolved over the past 20 years in parallel with the growth of critical care medicine and the stunning developments in the fields of neurology and neurosurgery. Although clinical trials are needed, there is preliminary evidence that induced hypertension and hypothermia can improve outcomes. The optimal threshold for transfusion of red cells remains unknown in patients with ischemic stroke and similarly further studies are needed to examine glycemic control and identify which patients may benefit most from aggressive insulin therapy. Finally, optimization of medical treatment is key in the care of the stroke patient and we should be cautious when prognosticating early in the setting of acute stroke and be aware of the potential effect ‘do not resuscitate’ status may have on patient outcome.
Prevalence of airflow limitation among employees in Norwegian smelters: a longitudinal study
Authors: Søyseth Vidar , Johnsen Helle Laier , Bugge Merete Drevvatne , Hetland Siri Merete , Kongerud Johny
Published: August 2010

Aims

To investigate the association between airflow limitation and occupational exposure and to compare a fixed limit with an age adjusted limit for airflow limitation.

Methods

3924 employees in 24 Norwegian smelters and related workplaces were investigated annually over 5 years (n=16 570) using spirometry and a respiratory questionnaire on smoking habits and job category. Employees working full time on the production line were classified as line operators; subjects who never worked on the production line were regarded as non-exposed. A job exposure matrix (JEM) was available in most smelters. Airflow limitation was expressed as (i) forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC ratio) <0.7 and (ii) FEV1/FVC ratio less than the lower limit of normal (LLN). Longitudinal analyses on the prevalence of airflow limitation were performed using a generalised linear mixed model.

Results

The prevalence of airflow limitation was stable during follow-up. The OR of airflow limitation during follow-up was 1.24 (95% CI 1.03 to 1.50) in line operators compared with unexposed subjects for FEV1/FVC ratio <0.7 and 1.44 (1.14 to 1.81) for FEV1/FVC ratio <LLN. A dose–response relationship was also found between prevalence of airflow limitation and dust exposure. The annual decline in FEV1was −77.5 (SD 99.9) ml/year in subjects with FEV1/FVC ratio <0.7 and −83.8 (114.2) ml/year in subjects with FEV1/FVC ratio <LLN.

Conclusion

Prevalence of airflow limitation was higher in exposed than non-exposed employees. Both the FEV1/FVC ratio <0.7 and FEV1/FVC ratio <LLN identify subjects with accelerated annual decline in FEV1.
Occupation and occupational exposure to endocrine disrupting chemicals in male breast cancer: a case–control study in Europe
Authors: Villeneuve Sara , Cyr Diane , Lynge Elsebeth , Orsi Laurent , Sabroe Svend , Merletti Franco , Gorini Giuseppe , Morales-Suarez-Varela Maria , Ahrens Wolfgang , Baumgardt-Elms Cornelia , Kaerlev Linda , Eriksson Mikael , Hardell Lennart , Févotte Joëlle , Guénel Pascal
Published: August 2010

Objectives

Male breast cancer is a rare disease of largely unknown aetiology. In addition to genetic and hormone-related risk factors, a large number of environmental chemicals are suspected of playing a role in breast cancer. The identification of occupations or occupational exposures associated with an increased incidence of breast cancer in men may help to identify mammary carcinogens in the environment.

Methods

Occupational risk factors for male breast cancer were investigated in a multi-centre case–control study conducted in eight European countries which included 104 cases and 1901 controls. Lifetime work history was obtained during in-person interviews. Occupational exposures to endocrine disrupting chemicals (alkylphenolic compounds, phthalates, polychlorinated biphenyls and dioxins) were assessed on a case-by-case basis using expert judgement.

Results

Male breast cancer incidence was particularly increased in motor vehicle mechanics (OR 2.1, 95% CI 1.0 to 4.4) with a dose–effect relationship with duration of employment. It was also increased in paper makers and painters, forestry and logging workers, health and social workers, and furniture manufacture workers. The OR for exposure to alkylphenolic compounds above the median was 3.8 (95% CI 1.5 to 9.5). This association persisted after adjustment for occupational exposures to other environmental oestrogens.

Conclusion

These findings suggest that some environmental chemicals are possible mammary carcinogens. Petrol, organic petroleum solvents or polycyclic aromatic hydrocarbons are suspect because of the consistent elevated risk of male breast cancer observed in motor vehicle mechanics. Endocrine disruptors such as alkylphenolic compounds may play a role in breast cancer.
Traffic-related air pollution and pregnancy outcomes in the Dutch ABCD birth cohort study
Authors: Gehring Ulrike , van Eijsden Manon , Dijkema Marieke B A , van der Wal Marcel F , Fischer Paul , Brunekreef Bert
Published: August 2010

Objectives

There is growing evidence for an adverse effect of maternal exposure to air pollution on pregnancy outcomes. As European data on this topic are limited, the aim of this study was to evaluate the impact of maternal exposure to traffic-related air pollution during different periods of pregnancy on preterm birth and fetal growth.

Methods

We estimated maternal residential exposure to NO2during pregnancy (entire pregnancy and trimesters) for 7600 singleton births participating in the Amsterdam Born Children and their Development (ABCD) prospective birth cohort study by means of a temporally adjusted land-use regression model. Associations between air pollution concentrations and preterm birth and fetal growth (expressed as small for gestational age and term birth weight) were analysed by means of logistic and linear regression models with and without adjustment for maternal physiological, lifestyle and sociodemographic characteristics.

Results

There was no indication of an increase in preterm birth among highly exposed women. Children of mothers with NO2levels in the highest exposure category on average had the highest term birth weight of all children and were among those with the lowest risk of being small for gestational age with little indication of a dose–response relationship.

Conclusions

In this study, there is no evidence for a harmful effect of estimated maternal exposure to traffic-related air pollution during pregnancy on pregnancy outcomes such as preterm birth, small for gestational age and term birth weight.
Circadian variation of heart rate variability among welders: Figure 1
Authors: Cavallari Jennifer M , Fang Shona C , Mittleman Murray A , Christiani David C
Published: August 2010

Objective

To compare the circadian variation of hourly heart rate variability (HRV) on work and non-workdays among boilermaker construction workers.

Method

A panel study of 18 males monitored by 24-h ambulatory ECG over 44 observation-days on paired work and non-workdays was conducted. ECGs were analysed and the SD of normal-to-normal beats index (SDNNi) was calculated from 5-min data and summarised hourly. SDNNis over work and non-workdays were compared using linear mixed-effects models to account for repeated measures and harmonic regression to account for circadian variation.

Results

Both work and non-work hourly HRV exhibited circadian variation with an increase in the evening and a decrease in the afternoon. SDNNiwas lower on workdays as compared with non-workdays with the largest, statistically significant differences observed between 10:00 and 16:00, during active working. Lower SDNNi, albeit smaller yet statistically significant differences, was also observed in the evening hours following work (17:00–21:00) and early morning (4:00). In regression models using all time periods, an average workday SDNNiwas 8.1 ms (95% CI −9.8 to −6.3) lower than non-workday SDNNi. The circadian pattern of HRV exhibited two peaks which differed on work and non-workdays.

Conclusion

While workday and non-workday HRV followed a circadian pattern, decreased HRV and variation of the circadian pattern were observed on workdays. Declines and changes in the circadian pattern of HRV is a concern among this exposed population.
Interactive effects of season and light environment on growth and leaf dynamics of evergreen tree seedlings in the humid subtropics
Authors: Cornelissen J. H. C.
Published: August 2010

Interactive effects of season and light environment on tree seedling growth were studied in four evergreen species in the humid subtropics of China. These species were the needle-leaved pioneer Pinus massoniana and the broad-leaved shade-tolerant Castanopsis fargesii, Sloanea leptocarpa, and Elaeocarpus japonicus. The experimental outdoor light environments, which broadly simulated those in forest gaps and clearings, were 100, 55, 33, and 18% of incident light quantity. Mean relative growth rates for both total leaf area and s tem height revealed interaction of season and light environment in Pinus, Castanopsis, and Elaeocarpus. In these species, mean relative growth rates were higher in summer in more shaded environments and in autumn in more exposed environments, but this shift was not as clear in Castanopsis. Winter growth was virtually nil in all species, although Pinus still achieved some winter stem height change. The hypothesis that late-successional rather than early-successional species would demonstrate interactions of season and light environment on growth and development was not sufficiently supported by the data. Variation in mean relative growth rates for total leaf area was due to changes in whole-plant average leaf size as well as leaf numbers. In Sloanea and Elaeocarpus seedlings in high light environments, reduced leaf size and enhanced leaf abscission rates gave rise to negative mean relative growth rates for total leaf area. The more sun-tolerant Castanopsis seedlings revealed no such leaf size response and shed few, if any, leaves in any of the light environments. These results indicate that seasonal variability in the growth response of tree seedlings to the light environment is an important factor to be taken into account in studies on gap dynamics of subtropical forests. Keywords: China, leaf area, leaf turnover, leaf size, mean relative growth rate, shade, subtropical, sun.