Period Of Exponential Growth Research Articles

The hepatitis C virus epidemic in Cameroon: Genetic evidence for rapid transmission between 1920 and 1960

Hepatitis C virus (HCV) infection in Cameroon is characterized by widespread seropositivity and great virus genetic diversity (3 genotypes and over 10 subtypes). A total of 244 HCV NS5B sequences of 382–405 bp long (95 type 1, 58 type 2, and 91 type 4) were phylogenetically analyzed to estimate the history of the HCV epidemic in Cameroon. The newly developed Bayesian coalescent approach was used to infer the history of each HCV type. The estimated dates of the most recent common ancestors (MRCA) for genotypes 1 (1500; 95% confidence interval (95% CI): 1300–1650) and 4 (1500; 95% CI: 1350–1700) were in the same range, while the date for genotype 2 MRCA (1600; 95% CI: 1400–1750) was slightly more recent. The mean genetic distance between HCV genotype 1 sequences was greater than that of HCV type 4 sequences, itself greater than that of HCV type 2 sequences. The initial infected populations of all three genotypes did not grow until recently, when they grew exponentially. The growth rate has now begun to slow, with a less steep exponential growth curve. The period of exponential growth of all the three genotypes was between 1920 and 1960. These results (i) confirm that HCV genotypes 1 and 4 have produced long-term endemics, (ii) suggest that genotype 2 was introduced into Cameroon more recently, and (iii) indicate that the exponential spread of the three genotypes between 1920 and 1960 coincided with the mass campaign against trypanosomiasis and mass vaccinations in Cameroon.

Detoxification of chromium slag by chromate resistant bacteria

This paper presented direct detoxification of chromium slag by using microorganisms. Our work showed that a bacterial consortium isolated from chromium slag can efficiently accelerate Cr(VI) leaching rate and remove it. The chromate resistant bacterial consortium consists of three strains. The detoxification efficiencies of the three respective strains follow the sequence: strain I > strain III > strain II. The detoxification capability of the bacterial consortium is far stronger than that of the respective strain, showing an excellent synergistic effect. The specific growth rates in pure and chromium-containing medium are 0.1475 and 0.1573 h −1, respectively. The presence of Cr(VI) has little effect on growth rate of the bacterial consortium. Cr(VI) removal takes place in exponential growth period of the bacterial consortium; the detoxification time should be controlled in this phase for every run. The kinetics of detoxification process was studied and can be described as η = 0.0615e 0.1573 t , which can be used to predict Cr(VI) removal efficiency.

Predictability of Extratropical Cyclones: The Influence of Initial Condition and Model Uncertainties

Abstract Errors in numerical weather forecasts can be attributed to two causes: deficiencies in the modeling system and inaccurate initial conditions. Understanding of the characteristics of the growth of forecast spread related to model uncertainty is less developed than that for initial condition uncertainty. In this research, the authors aim to construct a theoretical basis for describing such forecast error growth resulting from model uncertainty using mostly an empirical modeling approach. Primitive equation models with different vertical discretization and different horizontal resolutions are used to investigate the impacts of model uncertainties on the predictability of extratropical cyclones. Three sets of initial perturbations related to an upper-level trigger, with slightly different amplitudes, are designed for representing the situation when the initial condition uncertainty leads to significant forecast error growth. Forecast error growth is here estimated by following the properties of a developing cyclone in the simulations. Generally, there are three phases for forecast error growth in the experiments with initial condition and model uncertainties. For the experiments with the structured initial condition uncertainties, the errors grow rapidly at the earlier transient stage, with the growth rate well above the fastest growing normal mode. Afterward the error grows exponentially at approximately the same growth rate as the cyclone, followed by a saturation period, when the growth rate starts to decline. For the experiments with the model uncertainties, the forecast errors are initially zero and increase as time to a power of μ, which is between 0.5 and 3 depending on the strength of the cyclone at the time the simulation is initiated. After a certain time interval, the exponential growth phase and saturation period start as in the initial error experiments. Starting an integration with a stronger initial cyclone, the forecast error associated with the model uncertainty takes a shorter time to reach the exponential growth period and the forecast error grows more rapidly initially with a smaller value of μ. Also, when the initial cyclone is strong enough, then the exponential growth phase may only last for a very short time.

Drastic Reductions in Utilizable Fossil Fuel Reserves: An Environmental Imperative

We are living in a period of exponential growth of world population and energy consumption. Forecasts suggest that the atmospheric CO2 concentration could reach 750 p.p.m. by 2100. At this level, the coral reefs and the West Antarctic Ice Sheet would be lost and thermohaline circulation in the N. Atlantic could possibly shut down. Crippling the ocean conveyor system would have a major impact on world climate and jeopardize our chances of feeding an enlarged world population. Consumption of the total global hydrocarbon reserves would increase the atmospheric CO2 concentration to about 2200 p.p.m. We can therefore utilize less than 20% of the global hydrocarbon reserves without an accompanying massive programme for the sequestration of CO2 if we do not wish to cross the threshold atmospheric CO2 concentration of 750 p.p.m. and risk a major environmental catastrophe. Attention to the global CO2 problem will be the major task of the 21st Century.

The Fundamental Experiments of Red Tide Chemical Forecast

Many food algae and red tide algae were cultivated in the f/2 medium, and the nitric oxide (NO) concentration of the medium and the cell density were determined. The experiments on algae were conducted when different concentrations of NO were added into the medium using two methods. The results show that low concentrations of NO were self-produced by marine algae during the exponential growth period and were about nmol/L level. But at the end of the period, i.e., 2 or 3 days before the cell density reaches the maximum, an NO peak appeared, with the NO concentration reaching 10 nmol/L. The NO threshold concentration exists according to the influence of exogenous NO on the marine phytoplankton growth. One type is the threshold concentration that can promote algae growth, and its value is between 10 and 1 nmol level, or even lower. The other type can inhibit the phytoplankton growth, which is about μmol level or higher. The results indicate that red tide algae are far more sensitive to NO than are food algae. The fundamental experimental outcome above may provide a new clue for red tide chemical forecast by inspecting the NO change.

The obscuration by dust of most of the growth of supermassive black holes

Supermassive black holes underwent periods of exponential growth during which we see them as quasars in the distant Universe. The summed emission from these quasars generates the cosmic X-ray background, the spectrum of which has been used to argue that most black-hole growth is obscured. There are clear examples of obscured black-hole growth in the form of 'type-2' quasars, but their numbers are fewer than expected from modelling of the X-ray background. Here we report the direct detection of a population of distant type-2 quasars, which is at least comparable in size to the well-known unobscured type-1 population. We selected objects that have mid-infrared and radio emissions characteristic of quasars, but which are faint at near-infrared and optical wavelengths. We conclude that this population is responsible for most of the black-hole growth in the young Universe and that, throughout cosmic history, black-hole growth occurs in the dusty, gas-rich centres of active galaxies.

QCD plasma instabilities and isotropization

We solve the coupled Wong Yang–Mills equations for both U(1) and SU(2) gauge groups and anisotropic particle momentum distributions numerically on a lattice. For weak fields with initial energy density much smaller than that of the particles we confirm the existence of plasma instabilities and of exponential growth of the fields which has been discussed previously. Also, the SU(2) case is qualitatively similar to U(1), and we do find significant “abelianization” of the non-Abelian fields during the period of exponential growth. However, the effect nearly disappears when the fields are strong. This is because of the very rapid isotropization of the particle momenta by deflection in a strong field on time scales comparable to that for the development of Yang–Mills instabilities. This mechanism for isotropization may lead to smaller entropy increase than collisions and multiplication of hard gluons, which is interesting for the phenomenology of high-energy heavy-ion collisions.

Creation of a New Synthetic Medium for Culturing Helicobacter Pylori

We developed a scheme of consecutive replacement of complex components of a known Brucella medium containing peptones and blood with simple analogs and created a synthetic medium for Helicobacter pylori culturing. H. pylori cells require hemic iron for their growth; an appreciable increment in biomass was ensured by hemoglobin, but not simpler hemocontaining compounds (hemin and cytochrome C). Glutamine (20 g/liter) was used as the main nitrogen-containing component, and other amino acids were added in trace amounts. Adhesion was provided by adding agarose gel (0.1%) also promoting the increase in biomass. The proposed medium of a certain chemical composition differs from the known foreign analogs by the presence of hemocontaining component (hemoglobin), short period of exponential growth, and appreciable accumulation of cell protein.

Inhibitory Effect of 2′-Substituted Nucleosides on Hepatitis C Virus Replication Correlates with Metabolic Properties in Replicon Cells

Nucleosides have been widely used in the treatment of viral diseases, but relatively few have been identified as inhibitors of hepatitis C virus (HCV). The modified ribonucleosides, 2'-C-methyl-adenosine and 2'-O-methyl-cytidine, are potent inhibitors of HCV replication which specifically target the NS5B polymerase. Herein, a more extensive characterization of the effect of these compounds upon HCV replication in subgenomic replicons is reported. A highly selective antireplicative effect induced by the nucleosides in replicon-containing cell lines was maintained during an exponential growth period with potencies which paralleled the reduction of both positive- and negative-strand RNA replication. Moreover, the inhibitory effect closely correlated with the intrinsic metabolic properties of differing replicon clonal lines. Interestingly, while 2'-C-methyl-adenosine elicited similar inhibitory potencies in different cell lines, 2'-O-methyl-cytidine was found to be inactive in one replicon cell line tested, although the corresponding triphosphates comparably inhibited the in vitro activity of replication complexes isolated from these cells and the activity of NS5B polymerase using synthetic templates. The lack of antireplicative effect, attributed to poor intracellular conversion of the 2'-O-methyl-cytidine nucleoside to the active 5'-triphosphate, was reversed using a monophosphate prodrug. Thus, although replicon cells are useful for evaluating the effect of inhibitors upon HCV replication, these findings have important implications for their use in the identification and characterization of nucleosides and other chemotherapeutic agents requiring cellular metabolism.

Genetic analysis reveals the complex structure of HIV-1 transmission within defined risk groups

We explored the epidemic history of HIV-1 subtype B in the United Kingdom by using statistical methods that infer the population history of pathogens from sampled gene sequence data. Phylogenetic analysis of HIV-1 pol gene sequences from Britain showed at least six large transmission chains, indicating a genetically variable, but epidemiologically homogeneous, epidemic among men having sex with men. Through coalescent-based analysis, we showed that these chains arose through separate introductions of subtype B strains into the United Kingdom in the early to mid-1980s. After an initial period of exponential growth, the rate of spread generally slowed in the early 1990s, which is more likely to correlate with behavior change than with reduced infectiousness resulting from highly active antiretroviral therapy. Our results provide insights into the complexity of HIV-1 epidemics that must be considered when developing HIV monitoring and prevention initiatives.

Response of nonprotein thiols to copper stress and extracellular release of glutathione in the diatom Thalassiosira weissflogii

We studied the dynamic changes of cellular thiols and the extracellular release of glutathione (GSH) during growth of the marine diatom Thalassiosira weissflogii under varying levels of copper (Cu) addition in both metalbuffered (with EDTA) and unbuffered (without EDTA) media. The cell quotas of both thiols and pigments decreased with growth time; however, pigment-normalized cellular thiol concentrations at a given Cu exposure level were more or less conservative. In both media, specific growth rates of greater than 1 per day were obtained at total inorganic Cu concentrations of less than 80 nmol L−1; however, at higher Cu levels, cell growth was significantly suppressed. A dose-response relationship was observed between the phytochelatin-2 :GSH ratio and the Cu exposure level during the exponential growth period. GSH was released from the phytoplankton cells at similar concentrations in both media; therefore, the presence of a synthetic metal chelator does not affect thiol release, substantiating the premise that algae respond to inorganic species of Cu. GSH release was closely related to Cu-induced cell membrane damage. The extracellular GSH release rate was higher in normally grown cultures than in growth-limited cultures but lower than in growth-suppressed cultures. The excretion of GSH apparently reflects physiological conditions during algal growth rather than an enzymatic response of the algae to control trace metal speciation in the media. Therefore, the role of GSH in metal complexation in ambient waters is probably an inadvertent by-product of this process, although it could contribute a significant portion of Cu-complexing ligands in open ocean waters.

Population biomass, feeding, respiration and growth rates, and carbon budget of the scyphomedusa Aurelia aurita in the Inland Sea of Japan

We investigated the seasonal occurrence, wet : dry : carbon : nitrogen weight ratios, population biomass, gastric pouch contents, and rates of feeding, growth and respiration of the scyphomedusa Aurelia aurita in the central part of the Inland Sea of Japan. Aurelia aurita medusae began to appear in January/ February as ephyrae, reached annual maximum body size in July/August, and disappeared, presumably due to death, by November. Initial slow growth in early spring was followed by a period of exponentialgrowth(meangrowthrate:0.069d � 1 )betweenAprilandJuly.IntheOndoStrait,whichis characterized by strong tidal mixing, the A. aurita population (mean carbon biomass: 66.0 mg C m � 3 ) overwhelmingly dominated the zooplankton-community biomass (mean biomass of micro- and mesozooplankton: 23.7 mg C m � 3 ) between May and early August The gastric content analysis revealed that A. aurita ate almost all micro- and mesozooplankters, of which small copepods were most important. On the basis of digestion time for small copepods (60 min) and their abundance in the gastric pouch of field-collected A. aurita, we determined the weight specific feeding rates and clearance rates. The former increases linearly with increasing copepod abundance, but the latter was relatively constant irrespective of the food supply. We also measured the respiration rates of A. aurita and expressed them as functions of body weight and temperature. These physio-ecological parameters enabled us to construct the carbon budget of the A. aurita population typical of early summer in the Ondo Strait. Predicted population-feeding rate (6.07 mg C m � 3 d � 1 ) was higher than the population-food requirement for both metabolism and growth (4.55 mg C m � 3 d � 1 ), indicating that food supply was sufficient to sustain the observed growth rate. This feeding rate was equivalent to 26% of microand mesozooplankton biomass, a significant impact on zooplankton.

Phylogeographic analysis of the red seaweed Palmaria palmata reveals a Pleistocene marine glacial refugium in the English Channel

Phylogeography has provided a new approach to the analysis of the postglacial history of a wide range of taxa but, to date, little is known about the effect of glacial periods on the marine biota of Europe. We have utilized a combination of nuclear, plastid and mitochondrial genetic markers to study the biogeographic history of the red seaweed Palmaria palmata in the North Atlantic. Analysis of the nuclear rDNA operon (ITS1-5.8S-ITS2), the plastid 16S-trnI-trnA-23S-5S, rbcL-rbcS and rpl12-rps31-rpl9 regions and the mitochondrial cox2-3 spacer has revealed the existence of a previously unidentified marine refugium in the English Channel, along with possible secondary refugia off the southwest coast of Ireland and in northeast North America and/or Iceland. Coalescent and mismatch analyses date the expansion of European populations from approximately 128,000 BP and suggest a continued period of exponential growth since then. Consequently, we postulate that the penultimate (Saale) glacial maximum was the main event in shaping the biogeographic history of European P. palmata populations which persisted throughout the last (Weichselian) glacial maximum (c. 20,000 BP) in the Hurd Deep, an enigmatic trench in the English Channel.

EFFECTS OF FARGESIA DENUDATA DENSITY ON SEASONAL CHANGES IN LITTER NUTRIENT CONCENTRATIONS AND THEIR POTENTIAL RETRANSLOCATION

Dwarf bamboo (Fargesia denudata), a staple food of the giant panda, is the dominant synusia of the forest ecosystem in Wanglang National Nature Reserve, which plays an important role in the maintenance of forest ecosystem structure and function. The seasonal changes of nutrients in bamboo litter and nutrient retranslocation is one of the most profound ecological processes in the forest system. The seasonal change of nutrients in bamboo litter and nutrient retranslocation is regulated by the density of the bamboo stand as well as by biotic and abiotic factors. Although there have been a number of studies on nutrient cycling in bamboo forests, the effects of the bamboo density has not been investigated. The influence of bamboo density on the dynamics on litterfall, nutrient concentrations in bamboo litter, the differences in nutrient concentrations between litter and fresh leaves, and potential nutrient retranslocation were studied in three bamboo communities with different densities (D_1 with (220±11) stems·m -2, D_2 with (140±7) stems·m -2, and D_3 with (80±4) stems·m -2) beneath a bamboo-fir (Picea purpurea) forest. Plots were chosen that had similar slope, aspect, soil parent material and texture, tree canopy, etc. Bamboo litter was collected in each stand and fresh leaves collected over a growing period from May to October, 2003, and nutrient concentrations (C, N, P, K, Ca and Mg) analyzed. The results indicated that litterfall production of bamboo increased with stem density during the growing period. The concentrations of C, N, P and K in litter decreased with stem density, but Ca and Mg showed the opposite pattern. It was found that N, P and K concentrations were lower in litter than in fresh leaves, increased from May to July, and decreased after July. Carbon concentrations in both litter and fresh leaves did not vary with the stem densities and month. Calcium concentrations were higher in litter than in fresh leaves over the growing season, but there was no significant monthly variation. Litter had the lowest Mg concentrations in July (during the exponential growth period) whereas fresh leaves showed the opposite pattern. No significant monthly differences in nutrients were found among the three communities. The potential retranslocation capacity of P was strongly regulated by stem density, but N and K retranslocation was not influenced by stem density. The potential retranslocation capacity of N, P and K showed the ranked order as KNP. The retranslocation of C in bamboo was not significantly different among the three bamboo communities. The accumulation of Ca in litter increased with stem density. The accumulation of Mg in litter increased with stem density, but the retranslocation capacity decreased with stem density. Density, therefore, greatly influenced the seasonal changes of nutrient concentrations in litter and their potential retranslocation capacity.

The effect of propagule size on the invasion of an alien insect

1. The movement of species from their native ranges to alien environments is a serious threat to biological diversity. The number of individuals involved in an invasion provides a strong theoretical basis for determining the likelihood of establishment of an alien species. 2. Here a field experiment was used to manipulate the critical first stages of the invasion of an alien insect, a psyllid weed biocontrol agent, Arytainilla spartiophila Forster, in New Zealand and to observe the progress of the invasion over the following 6 years. 3. Fifty-five releases were made along a linear transect 135 km long: 10 releases of two, four, 10, 30 and 90 psyllids and five releases of 270 psyllids. Six years after their original release, psyllids were present in 22 of the 55 release sites. Analysis by logistic regression showed that the probability of establishment was significantly and positively related to initial release size, but that this effect was important only during the psyllids' first year in the field. 4. Although less likely to establish, some of the releases of two and four psyllids did survive 5 years in the field. Overall, releases that survived their first year had a 96% chance of surviving thereafter, providing the release site remained secure. The probability of colony loss due to site destruction remained the same throughout the experiment, whereas the probability of natural extinction reduced steeply over time. 5. During the first year colonies were undergoing a process of establishment and, in most cases, population size decreased. After this first year, a period of exponential growth ensued. 6. A lag period was observed before the populations increased dramatically in size. This was thought to be due to inherent lags caused by the nature of population growth, which causes the smaller releases to appear to have a longer lag period.

Wave damping as a critical phenomenon

The evolution of a monochromatic Langmuir wave in a collisionless plasma is studied using Vlasov simulations for a wide range of initial amplitudes. Three types of initial electron distributions are considered: Maxwellian, Lorentzian, and dilute warm Maxwellian plus dense cold component. It is shown that there exists a critical initial amplitude ε* that separates the damping and nondamping asymptotic regimes. Depending on the initial amplitude there are three main types of asymptotic evolution: (i) monotonic linear Landau damping below the threshold, ε≪ε*; (ii) the critical case ε≈ε*, when the field damps algebraically as E(t)∝t−3.26; (iii) at ε>ε* initial damping followed by a period of subsequent exponential growth and then irregular oscillations about a nonzero amplitude. This threshold is well described as a critical phenomenon, showing power-law dependencies on the distance from the threshold not only for field quantities, which are expected of second-order phase transitions in thermodynamics, but also for temporal ones. The critical exponent for both the initial damping and growth phases differ from those expected if the threshold is caused by O’Neil’s particle trapping in the wave potential. However, trapping affects the critical exponents well above the threshold and explains the characteristic frequency of oscillations above the threshold. It is found that for a Maxwellian plasma the threshold amplitude ε* corresponds to the condition that the trapping (bounce) frequency ωb equals the modulus of the theoretical Landau damping rate |γL|; at the threshold, qc=ωb/|γL|≈1. For Lorentzian and Maxwellian-plus-cold component plasmas this ratio is qLor≈0.84 and qCM≈0.83, respectively. The temporal and the field scalings are thus interrelated, suggesting that the inclusion of the temporal dimension is vital for critical phenomena in collisionless plasmas, in contrast to thermodynamic systems where the very small characteristic time to achieve equilibrium removes time from the scaling.

GROWTH AND DOMOIC ACID PRODUCTION BY PSEUDO‐NITZSCHIA SERIATA (BACILLARIOPHYCEAE) UNDER PHOSPHATE AND SILICATE LIMITATION1

Pseudo‐nitzschia seriata (Cleve) H. Peragallo isolated from Scottish west coast waters was studied in batch culture with phosphate (P) or silicate (Si) as the yield‐limiting nutrient at 15°C. This species produced the neurotoxin domoic acid (DA) when either nutrient was limiting but produced more when stressed by Si limitation during the stationary phase. Under P‐limiting conditions, exponential growth stopped after P was reduced to a low threshold concentration. Under Si‐limiting conditions, fast exponential growth was followed by a period of slower exponential growth, until Si became exhausted. A stationary phase was observed in the P‐limited but not the Si‐limited cultures, the latter showing a rapid decrease in cell density after the second exponential growth phase. Si‐limited cultures exhibited a further period of active metabolism (as indicated by increases in chl and carbon per cell) late in the experiment, presumably fueled by regenerated Si. DA production was low in exponential phase under both conditions. In P‐limited cultures, most DA was produced during the immediate postexponential phase, with little or no new DA produced during later cell senescence. In contrast, although a substantial amount of DA was produced during the slower exponential phase of the Si‐limited cultures, DA production was even greater near the end of the experiment, coincident with the period of chl synthesis and increase in carbon biomass. Comparison of the magnitude of toxin production in the two nutrient regimes indicated a greater threat of P. seriata‐generated amnesic shellfish poisoning events under Si rather than P nutrient limitation.

Travel Inn: everything you want for a good night's sleep – 100 per cent satisfaction guarantee or your money back

In the UK, following a period of exponential growth, the budget hotel market is maturing. In the classic product/service lifecycle model, this phase of development in a market is usually associated with strategies which engender strong brand loyalty; which strengthen and underpin market share; which develop competitive relative positioning and which serve to emphasize, via differentiation, unique brand benefits or propositions. This paper considers the strategies of Whitbread Travel Inn who, as the market leader, launched their 100 per cent Good Night satisfaction guarantee (or your money back) across the brand in 2001. To begin with a review of the budget hotel market is undertaken. This is followed by an analysis of the achievements of the guarantee over its first 18 months of operation, and consideration of the training approach that inculcated a new mind‐set within the organization. The paper concludes by reiterating the successes achieved and celebrates an award winning performance.

GROWTH AND ACCUMULATION OF TOTAL CAROTENOIDS IN TWO STRAINS OF Dunaliella salina Teod. (CHLOROPHYCEAE) FROM THE NORTHERN AND CENTRAL COAST OF PERÚ

In order to know the dynamics of growth and accumulation of total carotenoids in two strains of Dunaliella salina from the northern (Colan) and central (Chilca) coast of Peru, both strains were cultured during 40 days in controlled laboratory conditions, at 25±2°C, with 150 mol m-2 s-1, without aereation. The strains were grown in two culture media with two different salinities: a modified Johnson medium with addition of 15 and 23% NaCl and a Provasoli enriched seawater medium with 12.5 and 20% NaCl. A period of exponential growth during the first 5 days was observed in both strains, followed by a slow linear growth phase and a stationary phase which lasted until the end of the experiment (day 40). The maxima cellular densities were obtained in the modified Johnson medium at 15% NaCl in both strains, being higher in Chilca (2.2x106 cell mL-1) than in Colan (1.6x106 cell mL-1). The accumulation of total carotenoids per volume was similar in both strains but different in both media; the highest values were obtained in the Provasoli medium with 20% NaCl (13.3± 2.9 mg L-1, Colan and 10.6± 2.5 mg L-1, Chilca). On the contrary, the total content of carotenoids per cell was different in both strains and media; the highest values were obtained in the Provasoli medium with 20% NaCl (110.9± 0.7 and 58.7± 1.3 pg cell-1 in the strains Colan and Chilca, respectively)

Rapid monitoring for the potentially ichthyotoxic dinoflagellate Cochlodinium polykrikoides in Korean coastal waters using fluorescent probe tools

Cochlodinium polykrikoides has occurred annually in Korea’s coastal waters since 1982, where it has caused extensive fish mortality. Rapid and accurate monitoring is very important to reduce the economic damage caused by C. polykrikoides. However, before outbreaks of C. polykrikoides occur, single cells are often more abundant than chain-forming cells. During this period, it is very difficult to discriminate C. polykrikoides from closely related dinoflagellates and other phytoplankton species. The aim of the present study was to identify even single-celled C. polykrikoides and to assess counting methodologies using molecular probes. A new polyclonal antibody bound specifically to C. polykrikoides, and not to other phytoplankton, including the morphologically similar Gyrodinium impudicum and Gymnodinium catenatum. When cultured C. polykrikoides cells were fixed with 2.5% glutaraldehyde, they emitted a high-intensity fluorescent signal during the period of exponential growth. The correlation with cell density of a mixed culture including C. polykrikoides treated with an antibody and lectin probes (wheat germ agglutinin/Erythrina cristagalli agglutinin) was well matched (r 2 = 0.83). The detection of C. polykrikoides was possible at concentrations as low as 5 cells ml � 1 . Reaction with C. polykrikoides antisera and antigen by western blotting analysis was at � 30 kDa and gave no signal for G. impudicum, G. catenatum, Alexandrium tamarense or Prorocentrum micans. Consequently, the new antibody is of great importance for enumeration and identification of C. polykrikoides in Korea’s waters.