Reproduction in Anthelia glauca (Octocorallia: Xeniidae). I. Gametogenesis and larval brooding

Anthelia glauca Lamarck, 1816 is a gonochoric, external-brooding soft coral found in KwaZulu-Natal. It is reproductively active in the summer months. The development of gametes produced in late summer is arrested in winter. Several stages of gametes are found at the base of the polyps, and female polyps produce several cycles of larvae over an extended breeding period of 4 to 5 months. Larvae are brooded in a unique pharyngeal brooding pouch not yet described in other coral species. The brood pouch consists of an expansion of the pharynx with constrictions proximal and distal to the embryos and larvae. Our data suggest that egg transfer and fertilization occur at full moon and the mature larvae are released after new moon. Zooxanthellae are absent in A. glauca oocytes, but zooxanthella infestation commences at the immature larval stage. Received: 15 July 1997 / Accepted: 12 March 1998     

Short retention times of stomach temperature loggers in free-living seabirds: is there hope in the spring?

Stomach temperature loggers have proved useful for the study of feeding activity in free-living seabirds, but their usage has been restricted because they are frequently dislodged and lost during the seabirds' regular regurgitation of indigestible prey remains. In the present study we examine the incidence of spontaneous regurgitation (pellet production) in free-living seabirds, consider the effect this has on the likely retrieval of stomach temperature loggers and present a structural modification of the logger housings which leads to a much lower incidence of regurgitation. Systems were tested on albatrosses, cormorants, gannets and penguins. Received: 15 July 1997 / Accepted: 31 October 1997     

Oligogyny by unrelated queens in the carpenter ant, Camponotus ligniperdus

Multilocus DNA fingerprinting and microsatellite analysis were used to determine the number of queens and their mating frequencies in colonies of the carpenter ant, Camponotus ligniperdus (Hymenoptera: Formicidae). Only 1 of 61 analyzed queens was found to be double-mated and the population-wide effective mating frequency was therefore 1.02. In the studied population, 8 of 21 mature field colonies (38%) contained worker, male, or virgin queen genotypes which were not compatible with presumed monogyny and therefore suggested oligogyny, i.e., the cooccurrence of several mutually intolerant queens within one colony. Estimated queen numbers in oligogynous colonies ranged between two and five. According to the results of the genetic analysis, most of the queens coexisting in oligogynous colonies were not closely related. Pleometrosis is very rare and queenless colonies adopt mated queens both in the laboratory and field. Therefore, the most plausible explanation for the origin of oligogynous colonies in C. ligniperdus is the adoption of unrelated queens by orphaned mature colonies. The coexistence of unrelated, but mutually intolerant queens in C. ligniperdus colonies demonstrates that oligogyny should be considered as a phenomenon distinct from polygyny. Received: 18 December 1997 / Accepted after revision: 20 June 1998     

The Statistical Investigation on Posidonia Oceanica (L.) Delile Meadows in Izmir, Turkey

In this study, variance analysis technique on unbalanced data was examined, and in this sense, Type II (fitting constants) methods were studied. The aim of this study was to show that meaningful evaluations can be performed even in unbalanced conditions and to contribute to the present investigations in biological area. In the implementation part of the study, the juvenile leaf densities of Posidonia oceanica—which is a sea grass that grows in Izmir Bay, and has very important ecological effects—in various regions and in various depths were determined. The results revealed that depth affect number of juvenile leaf (d.f.?=?3, F?=?523.90, R ²?=?0.998, p?F?=?41.53, p?F?=?19.65, p?p?p?p?p?相似文献   

Risk of boron and heavy metal pollution from agro-industrial wastes applied for plant nutrition

In this study, the effects of various agro-industrial wastes were investigated when applied to soil alone or in combination with chemical fertilizers, regarding the risks of boron and heavy metal pollution of soils and plants. Nine combinations of production residues from various agro-industries, urban wastes, and mineral fertilizers were applied to potatoes in a field experiment. The content of available boron in the soil differed significantly (p < 0.05) among the applications. Generally, B values were found to be slightly higher when soapstock, prina, and blood were used alone or in combination. Although total Co, Cd, and Pb contents of soils showed no significant differences between the applications, Cr content differed significantly (p < 0.05). No pollution risk was observed in soil in respect to total Co, Cd, Pb, and Cr contents. The amount of boron and heavy metals in leaves showed no significant differences among the applications. Cobalt, Cd, and Pb in leaves were at normal levels whereas Cr was slightly above normal but well under the critical level. Boron was low in tubers and varied significantly between applications such as Co and Cd. The Co content of tubers was high, Cd and Cr contents were below average, and Pb content was between the given values. Some significant correlations were found between soil characteristics and the boron and heavy metal content of soil, leaves, and tubers.     

Organochlorine pesticide residue levels in blood serum of inhabitants from Veracruz, Mexico

The objective of the present study was to monitor the levels of organochlorine pesticides HCB; α-, β-, γ-HCH; pp'DDE; op'DDT; and pp'DDT in blood serum of Veracruz, Mexico inhabitants. Organochlorine pesticides were analyzed in 150 blood serum samples that constituted that which remained after clinical analyses, using gas chromatography-electron-capture detection (GC-ECD). The results were expressed as milligrams per kilogram on fat basis and micrograms per liter on wet weight. Only the following pesticides were detected: p,p'-DDE was the major organochlorine component, detected in 100% of samples at mean 15.8 mg/kg and 8.4 μg/L; p,p'-DDT was presented in 41.3.% of monitored samples at mean 3.1 mg/kg and 1.4 μg/L; β-HCH was found in 48.6% of the samples at mean 4.9 mg/kg and 2.7 μg/L; op'DDT was determined to be in only 3.3% of monitored samples at mean 2.7 mg/kg and 1.4 μg/L. The pooled samples divided according to sex showed significant differences of β-HCH and pp'DDE concentrations in females. The samples grouped according to age presented the third tertile as more contaminated in both sexes, indicating age as a positively associated factor with serum organochlorine pesticide levels in Veracruz inhabitants.     

Bioremediation of heavy metals using biostimulation in laboratory bioreactor

The present research study investigates bioremediation potential of biostimulated microbial culture isolated from heavy metals waste disposal contaminated site located at Bhayander (east), Mumbai, India. The physicochemical and microbial characterization including heavy metal contaminants have been studied at waste disposal site. The microorganisms adapted at heavy metal-contaminated environment were isolated, cultured, and biostimulated in minimal salt medium under aerobic conditions in a designed and developed laboratory bioreactor. Heavy metals such as Fe, Cu, and Cd at a selected concentration of 25, 50, and 100?μg/ml were taken in bioreactor wherein biostimulated microbial culture was added for bioremediation of heavy metals under aerobic conditions. The remediation of heavy metals was studied at an interval of 24?h for a period of 21?days. The biostimulated microbial consortium has been found effective for remediation of Cd, Cu, and Fe at higher concentration, i.e., 100?mg/l up to 98.5%, 99.6%, and 100%, respectively. Fe being a micronutrient was remediated completely compared to Cu and Cd. During the bioaccumulation of heavy metals by microorganisms, environmental parameters such as pH, total alkalinity, electronic conductivity, biological oxygen demand, chemical oxygen demand, etc. were monitored and assessed. The pilot scale study would be applicable to remediate heavy metals from waste disposal contaminated site to clean up the environment.     

Occupational and environmental aerosol exposure assessment: a scientific journey from the past, through the present and into the future

This paper reviews how aerosol exposure assessment, for people in both working and living environments, has evolved over the years. It charts the main scientific developments that led to progressively improved ways of thinking and methods to assess exposure to airborne particulate matter in a manner more relevant to human health. It has been a long scientific journey as one generation of pioneering contributors has handed off to the next. In the process a consistent rationale has emerged, producing aerosol sampling criteria--and in turn exposure standards--which have been increasingly relevant to actual human exposures. The journey continues as a new generation of scientists steps up to deal with the new challenges that are emerging. An appreciation of the history of what went before is essential to charting the most effective path looking forward.     

Gene-TEQ--a standardized comparative assessment of effects in the comet assay using genotoxicity equivalents

Existing methods for the comparison of genotoxic effects in the comet assay bear considerable disadvantages such as the problem to link information about concentration dependence and severity of effects. Moreover, given the lack of standardized protocols and the use of various standards, it may be extremely difficult to compare different studies. In order to provide a method for standardized comparative assessment of genotoxic effects, the concept of genotoxicity equivalents (Gene-TEQ) was developed. As potential reference compounds for genotoxic effects, three directly acting (N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), methyl-methanesulfonate, and N-methyl-N-nitrosourea) and three indirectly acting (cyclophosphamide, dimethylnitrosamine, and 4-nitroquinoline-oxide) genotoxic substances were compared with respect to their cytotoxic (neutral red) and genotoxic (comet assay) concentration-response profiles in the permanent fish cell line RTL-W1. For further comparison, two sediment extracts from the upper Danube River were investigated as environmental samples. Based on the results of cytotoxicity and genotoxicity testing, MNNG was selected as the reference compound. At several exposure levels and durations, genotoxic effects of both the other pure substances and the environmental samples were calculated as percentages of the maximum MNNG effect and related to the absolute MNNG effect (EC values). Thus, genotoxicity equivalent factors (Gene-TEQs) relative to MNNG could be calculated. Gene-TEQs can easily be applied to pure substances, mixtures and field samples to provide information about their toxicity relative to the reference compound. Furthermore, the Gene-TEQ concept allows a direct comparison of environmental samples from different laboratories.     

A Framework for Comprehensive,Integrated, Watershed Monitoring in New York City

The International Life SciencesInstitute (ILSI) Risk Science Institute (RSI) convenedan expert panel of scientists to developrecommendations for a comprehensive monitoring programfor the Croton and Catskill/Delaware watersheds, whichprovide drinking water to New York City's residents. This effort was conducted as part of efforts topreserve and enhance the quality of New York City'sreservoir system through a watershed protectionprogram. The panel developed recommendations for astrategic framework on which to construct a monitoringprogram. As part of this activity, the paneldetermined whether existing monitoring activities weredeficient and, where activities were deficient, thepanel developed recommendations for additionalinformation that should be collected.The panel recommended the development and use of anintegrated approach to watershed monitoring, whichdraws on modeling, risk-based planning and analysis,statistical sampling and design, and basic compliancemonitoring. The approach should be designed toprovide an assessment of natural and anthropogenicsources of stress to the system as well as anassessment of water quality trends in response tostresses acting in concert, both over the long termand over the five-year New York City Memorandum ofAgreement (MOA) assessment time frame. It should alsoprovide an assessment of the human health andenvironmental risks posed by a variety of stressors,and the impact of management actions implemented toameliorate stressors.