Influence Of Substratum Research Articles

Effects of substrata and conspecific odour on the metamorphosis of mangrove crab megalopae, Ucides cordatus (Ocypodidae)

Environmental cues associated with the adult habitat induce metamorphosis in many marine invertebrate larvae and thus settlement in a place appropriate for completing their life cycle. Ucides cordatus is a semi-terrestrial crab that exemplifies organisms living in mangrove estuaries as adults, but whose larvae develop offshore and return to the estuarine environment prior to metamorphosis. We investigated the influence of substrata (burrow mud, channel-bank mud, dead wood, sand, nylon mesh) and conspecific adult cues (crab-conditioned seawater) on metamorphosis and the duration of the megalopal phase. Our results suggest that U. cordatus megalopae settle in areas populated by conspecific crabs and/or muddy habitats. High moulting rates were observed in the treatments with mud and/or adult odour (67–91%), whereas in the other substrata treatments and in the seawater control less than 20% and 5% of the megalopae metamorphosed, respectively. Megalopae are also capable of delaying metamorphosis. Over channel-bank mud they moulted 8 days later at an average, compared to the treatment with crab-conditioned seawater. Such a delay could result in a reduced juvenile fitness. In seawater control almost all megalopae died prior to metamorphosis, without moulting spontaneously as observed in other species. This reflects the crucial importance of habitat cues for the settlement and recruitment of this ecologically and economically important species. We outline the necessity of future research concerning post-metamorphic carry-over effects, the possible role of biofilms in absorbing and/or producing settlement cues, as well as the question whether the megalopae react specifically to the odour of U. cordatus, or also to the one of other crab other species. The latter is of particular interest against the background of the spreading lethargic crab disease that results in massive mortalities of U. cordatus, but not of co-occurring-species.

Detection of salivary α‐amylase and lysozyme exposed on the pellicle formed in situ on different materials

Amylase and lysozyme are components of the salivary pellicle, exposing considerable enzymatic activity in the immobilized state. The purpose of the present study was to elucidate the influence of different solid substrata on the amount and distribution of amylase and lysozyme exposed on the surface of the salivary pellicle formed in situ. Slabs of titanium, feldspar ceramic, and bovine enamel were fixed on the buccal sites of individual splints worn by three subjects for 3 or 30 min, respectively, to allow pellicle formation. Subsequently, slabs were removed from the splints and rinsed with running water. Detection of amylase and lysozyme was performed by FEI-SEM after gold-immunolabeling of the enzymes. Both enzymes were found to be distributed randomly at the pellicle surface. Irrespective of formation time and substratum, significantly more labeled lysozyme molecules (5.23 +/- 4.5 microm(-2)) were detected compared with amylase (3.4 +/- 2.9 microm(-2)). Neither the substratum nor the pellicle formation time had significant impact on the amount of the respective enzyme that could be detected. This study for the first time provides evidence, that amylase and lysozyme are exposed at the surface of the salivary pellicle formed in situ on titanium and ceramics. Both enzymes are distributed randomly on the surface of the pellicle, irrespective of the underlying substratum.

The effect of different substrates on pearl oyster Pinctada martensii (Dunker) larvae settlement

In the present study, the effect of various substrata on the settlement of a pearl oyster, Pinctada martensii, was evaluated. The settlement of the larvae in the experiments with four different color substrata was compared and showed that deep color plastic sheets (red and blue) attracted significantly more larvae ( P < 0.05) than light color (green and yellow). In addition, the influence of biofilm substrata was compared with that of non-film substrata of smooth or rough texture. Number of settled larvae was highest on biofilmed plastic sheets, either rough or smooth, then rough plastic sheets without film, the least recorded was on smooth plastic sheets without biofilm. Substrates of plastic sheets coated with tissue extracts of the same species appeared to attract larval settlement. The number of settled larvae on substrates with tissue extracts was significantly greater ( P < 0.05) than that on the control.

Ceramide and sphingomyelin species of fibroblasts and neurons in culture

The ceramide (Cer) and sphingomyelin (SM) species of cultured differentiated rat cerebellar granule cells and human fibroblasts were characterized by electrospray ionization-mass spectrometry. We identified 35 different species of Cer and 18 species of SM in human fibroblasts, and 35 different species of Cer and 9 species of SM were characterized in rat neurons. The main Cer species of rat cerebellar granule cells contained d18:1 sphingosine linked with palmitic, stearic, or nervonic fatty acid, and the two main SM species were d18:1,16:0 and d18:1,18:0. Both sphingolipids were enriched in detergent-resistant membranes (DRMs; or lipid rafts), and significant differences were found in the sphingolipid patterns of DRMs and of detergent-soluble fractions (DSF) from these cells. In human fibroblasts, the main Cer species were d18:1,16:0, d18:2,16:0, d18:1,24:0, d18:2,24:0, d18:1,24:1, and d18:2,24:1; the most represented species of SM were d18:1,16:0, d18:1,24:0, and d18:1,24:1. In these cells, SM was highly enriched in DRMs and Cer was mainly associated with DSF, and the species found in DRMs were markedly different from those found in DSF.

Attenuation of genotoxicity under adhesion-restrictive conditions through modulation of p53,γ H2AX and nuclear DNA organization

Interactions between tumor cells and their substratum influence cancer progression by modulating cell proliferation and survival. We now investigated whether signaling responses to UV irradiation differ on adhesion-permissive or restrictive substrates. The latter conditions diminished spreading and proliferation of neo 6.3/C8161 melanoma in which metastasis is suppressed by introduction of neo-tagged chromosome 6, but permitted proliferation of human metastatic C8161 melanoma. Apoptosis-associated PARP cleavage and DNA fragmentation induced by UV irradiation were diminished on the restrictive substrate in C8161 melanoma. Genotoxic responses to UV irradiation like persistent increases in the phosphorylation of histone H2AX, induction of the tumor suppressor p53 protein and greater binding of this protein to its DNA consensus sequence, were all decreased on the restrictive substrate. The latter also promoted a 2 fold increase of DNA condensation in chromatin and enhanced activation of the survival - and invasion-associated MMP-9 gelatinase B, preferentially in metastatic C81261 melanoma. Our data suggest that adaptation to restrictive substrates in metastatic C8161 melanoma decreases UV-induced apoptosis, partly through attenuation of DNA damage signaling responses and changes in genomic organization.

Some Observations on Proto-Austronesian *t to k

1. INTRODUCTION. (1) This note provides information on another language that exhibits the PMP *t > k change discussed Blust (2004), namely Makuva of East Timor, and suggests that this change (which also involves an apparent merger of original *k and *t) has not come about through substratum influence from the neighboring dominant non-An language Fataluku. The author also takes issue with some misunderstandings of Caddoan data the subsequent squib by Donohue (2006), and presents the correct facts. 2. PMP *T > K: ANOTHER INSTANCE. The recent squib by Mark Donohue (Donohue 2006) addresses some of the issues raised the account provided by Blust (2004) of the change from PMP *t to /k/ some 43 daughter languages. This change actually represents at least 20 historically independent instances of *t > k change, including three historically separate instances of this Polynesian. Striking sound-changes Austronesian are not infrequent, as the extensive treatment of ten such changes Blust (2005) makes clear, (2) but the change of *t > k is unusually widespread within Austronesian, and the nature of its geographical and genetic distribution makes it clear that this change is not an exclusively shared innovation that serves to mark off a single cluster of related languages. Donohue points out that the reverse change, that from *k to t the world's languages, is even rarer, though it does occur, for instance, some young children's speech output. (3) In this paper I wish to add an example of a further Austronesian language that exhibits the *t > k change, and also to correct some observations by Donohue on stop systems the Caddoan languages of North America, particular Pawnee. The language that is to be added to Blust's collection as showing further examples of PMP *t > k is Makuva, formerly also known as Maku'a, Lovaia, or Loikera. This is a Central Malayo-Polynesian language closely related to Meher and other languages of Kisar that is spoken far eastern East Timor near Tutuala and Lospalos and that is arguably the easternmost indigenous language of East Timor. Speakers of Makuva (who any case are dominant Fataluku, a non-Austronesian language that may be a member of the Trans New Guinea phylum) are few, data are scarce, and Makuva data to which I have had access are scarcer yet. My own knowledge of the language is confined to the report van Engelenhoven and Cailoru (2006), and to the set of cardinal numerals Hull (2004). (4) Indeed, van Engelenhoven and Cailoru (2006) suggest that Makuva, whatever its origins, is now functionally a language in coma, one that is simply known to a minority of mature speakers of Fataluku as a ritual language for use on certain social occasions. In Makuva, PMP k apparently remains as k at least some cases (n-kaku afraid t) is not rare Austronesian and is parallel with the same change Palauan (Josephs 1990), where, as has long been known, PMP *s became t (tut 'breast' from PMP *susu) and PMP *t became [??], written the modern orthography, except when it was preserved intact postconsonantally (so that both reflexes are presented Palauan dakt [[??]akt] 'afraid'

에스라기 아람어 본문에 나타난 고대 페르시아어 기저 영향 : 에스라기 4장 7하반절의 번역을 중심으로

에스라기 아람어 본문에 나타난 고대 페르시아어 기저 영향 : 에스라기 4장 7하반절의 번역을 중심으로

Influence of different restorative materials on lysozyme and amylase activity of the salivary pellicle in situ

Lysozyme and amylase are the most abundant enzymatic components in the salivary pellicle. The purpose of the present study was to determine the influence of different substrata on amylase and lysozyme activity in salivary pellicles formed in situ. Slabs (5 mm diameter) of bovine dentine and enamel, of titanium, gold alloy, resin composite, PMMA, amalgam, and feldspar ceramic were fixed on the buccal sites of individual splints worn by six subjects for 30 min to allow pellicle formation. Thereafter, slabs were removed from the trays and rinsed with running water. Lysozyme activity was determined via lysis of Micrococcus lysodeicticus. Amylase activity was measured with a photometric method using 2-chloro-4-nitrophenyl-4-O-beta-D-galactopyranosylmaltotriosid (GalG2CNP) as substrate. Both pellicle enzymes were evaluated in the immobilized as well as in the desorbed state. Salivary enzyme activities were also measured. All investigated pellicles exhibited lysozyme and amylase activity. Great intraindividual and interindividual differences were observed. Over all samples, immobilized amylase activity amounted to 0.65 +/- 0.64 mU/cm2. Immobilized lysozyme activity was 5.04 +/- 1.55 U/cm2. There were no major effects of the substratum on pellicle-bound amylase and lysozyme activity. Immobilized and desorbed enzyme activities revealed a strong correlation (lysozyme: r = 0.700; amylase: r = 0.990). Salivary enzyme activities had only little impact on pellicle-bound enzyme activities. Amylase and lysozyme are incorporated in the acquired in situ pellicle on different solid surfaces in an active conformation. Dental material and enzyme activity in the saliva have only little impact on enzymatic activity in the pellicle in situ.

Influence of substratum on the degradation processes in diesel polluted sub-Antarctic soils (Crozet Archipelago)

Biodegradation by naturally occurring populations of microorganisms is a major mechanism for the removal of oil hydrocarbons from the environment. Therefore, follow-up of bacterial populations and chemical indices of biodegradation are important components of contaminated site assessment studies. Over a 4-year period following an accidental diesel contamination of the sub-Antarctic Crozet Archipelago (51°51′E–46°25′S), a field study was carried out in the contaminated area that is located in a transition zone between an arid fell-field (upstream) and a wet vegetated area (downstream). This study included a monitoring of heterotrophic and hydrocarbon-degrading bacterial abundance and chemical analysis of the remaining hydrocarbons. Significant higher number of heterotrophic and hydrocarbon-degrading bacterial counts revealed a rapid acclimation of sub-Antarctic microbial soil communities to the diesel fuel contamination. A chemical survey conducted during the last 2 years (2002 and 2003) showed that the total extractable hydrocarbons (TPH) content in arid fell field was reduced to ≤50% of their value while it was reduced only to ≤65% in vegetated soil. In addition, the decrease of TPH was always higher in the presence of fertilizer in the arid contaminated area, while fertilizer addition was almost inefficient in the wet contaminated one. All these results demonstrate a serious influence of the soil properties on the degradation rate. However, all chemical indices showed a significant reduction of alkanes and light aromatics in both contaminated area confirming a regular oil degradation process.

Moss inhabiting nematodes: influence of the moss substratum and geographical distribution in Europe

AbstractThe impact of the moss substratum (soil or rock) on the species composition of nematode assemblages was investigated. Samples of different species of moss were collected at several stations in Italy. Nematode density was very variable between samples and substrata, but nematode assemblages were very similar in trophic group structure and diversity. Predator dominance and the high percentage of Dorylaimida indicate the good quality of the investigated stations. Species richness and biomass were higher in mosses growing on soil where large nematodes such as Aporcelaimellus obtusicaudatus were abundant. No clear substratum-dependent species pattern was found: only Tripylella intermedia appears to be exclusive for mosses growing on rocks. Prionchulus muscorum and Plectus acuminatus were the commonest species and occurred in almost all samples. By comparing our moss communities with those of other European communities reported in the literature, we detected significant differences between continental and Mediterranean communities.

Contact-induced changes

Traditionally, contact-induced changes in languages have been classified into two broad categories: those due to ‘borrowing’ and those due to ‘interference’ by an L1 or other primary language on an L2 in the course of second language acquisition (SLA). Other terms used for ‘interference’ include ‘substratum influence’ and ‘transfer.’ Inconsistencies in the use of these terms pose a problem for the classification and analysis of the outcomes of contact-induced change. Moreover, labels like these, unfortunately, have been used to refer both to the outcomes of language contact and to the processes that lead to such results. This imprecision in the use of key terms poses serious problems for our understanding of what is actually involved in the two types of crosslinguistic influence. Moreover, it has led to inaccuracy in our assignment of changes to one or the other category. The aim of this paper is to reassess the conventional wisdom on the distinction between borrowing and ‘interference,’ and to clarify the vehicles of change as well as the outcomes characteristic of each. My approach is based on Van Coetsem's (1988) distinction between two transfer types – borrowing under RL agentivity, and imposition under SL agentivity, with their shared but differently implemented processes of imitation and adaptation. Crucially, this approach recognizes that the same agents may employ either kind of agentivity, and hence different transfer types, in the same contact situation. It is the failure to recognize this that has sometimes led to inaccuracy in accounts of the nature and origins of contact-induced changes, as well as to conflicting classifications of the outcomes of contact. The present paper proposes a more rigorous and consistent classification, based on the kinds of agentivity involved.

Stasis or kinesis? Hidden dynamics of a rocky intertidal macrophyte mosaic revealed by a spatially explicit approach

Macrophyte mosaics, or tile-like assemblages of turfy marine macroalgae and surfgrass ( Phyllospadix scouleri), are persistent and highly diverse along the central Oregon coast. To test the hypothesis that spatial pattern and species abundances are relatively invariant in this system, we studied community structure, disturbance, and species interactions from 1985 to 1990. Abundances and disturbance in permanently marked plots at each of five sites spanning wave-exposed to wave-protected areas were monitored photographically each year. The analysis was spatially explicit, incorporated position effects, and allowed determination of species displacements. To interpret the potential influence of substratum on disturbance, we quantified rock hardness and sediment depth at each site. Field experiments tested the role of grazers and spatial interactions on maintenance of between-patch boundaries. Mosaic dynamics varied with wave exposure. At wave-exposed and wave-protected sites, average patterns of abundance and assemblage structure were relatively constant through time, but analysis of transition probabilities showed high rates of change among mosaic elements at wave-exposed sites and low rates of change at wave-protected sites. At wave-exposed sites, most changes involved Phyllospadix displacing neighboring macroalgal turfs but rarely the reverse. At all wave-exposures, surfgrass was the most frequently disturbed mosaic element. Disturbed areas were quickly colonized by macroalgae. At wave-exposed sites, disturbances were closed by regrowth of surfgrass. Disturbance rates were similar across wave-exposures, with wave forces causing most loss at wave-exposed sites and a combination of substratum failure and sediment burial causing most loss at wave-protected sites. At wave-exposed sites, disturbances tended to be larger (436.7 vs. 278.6 cm 2) but less numerous (228 vs. 484 total disturbances) than at wave-protected sites. At wave-exposed sites, surfgrass overgrew all other species except the kelp Lessoniopsis littoralis, which was competitively equivalent to surfgrass. Grazing had no effect on spatial interactions. Disturbance prevented surfgrass monocultures, and with variable dispersal and patchy recruitment, maintained mosaic structure. At wave-protected sites, standoffs were the usual outcome of interactions, and patchiness resulted primarily from colonization of disturbances and subsequent succession. Like mussels, Phyllospadix are simultaneously dominant competitors, the most disturbance-susceptible species, and poor colonizers. These features are shared by theoretical models exploring the processes underlying spatially structured assemblages, and may characterize spatially structured systems in general.

Electronic Nose for the Early Detection of Moulds in Libraries and Archives

The development of sensor technology has stimulated interest in the use of characteristic volatile and odorous compounds produced by fungi as early indicators of deterioration in materials. Sensor arrays to measure traces of volatile chemicals could detect early fungal growth in libraries and archives. In this study we tested an electronic nose to detect fungi actively growing on paper samples. The main aim was to verify whether or not a device, currently used to detect fungal activity in stored grain, might be suitable for detecting mould activity on paper. The findings indicate that it is possible to discriminate “ in vitro” between paper samples affected by moulds and those unaffected, both at 100% RH (relative humidity), and at 75% RH, simply by measuring their odour fingerprint with an electronic nose. The sensors used in this study discriminated for each paper type three different species of actively growing fungi. Cluster analysis (CA) showed that it was possible to differentiate between specific species. Different paper types influenced the emission of odorous signals by moulds. When considering data from all the paper types, principal component analysis (PCA) indicated that only samples analysed at 100% RH could be separated. This study suggests that, before electronic-nose technology can be applied to the early detection of mould growth in libraries, archives, museums or in display cases, more information will be required on the influence of substrata and of other environmental parameters in the production of volatile chemicals by fungi.

Herrscherschaft and herrschersuffix in Central-East European languages

The paper resumes a topic the author approached in severa[ instances beginning with 1987: some specific terms referring to the semantic sphere Herrscherschafi. In Romanian, ban, jupîn, stăpîn and probably also cioban reflect the indigenous Thracian substratum; these forms also reflect the archaic Indo-European Herrschersujfzx -n-. In Slavic, their equivalent forms ban, župan and stopan reflect either a Late Thracian or (Proto-)Romanian influence. Equally Rom. vătaf reflects the substratum influence, whereas Slavic vatah, vatak, vataš reflects the same borrowing. On the other hand, Slavic gospodƄ, belongs to the archaic Proto-Slavic core elements, while cěsaŕƄ, reflect a Germanic influence. Finally, Rom. boier is an East-Romance innovation derived from bou 'ox' and initially meant 'owner of cattle = rich man', a traditional association between cattle-owners and richness. The word had a large distribution from the early Middle Ages until late in the 20th century.In a paper written some 15 years ago (Paliga 1987, in Linguistica, Ljubljana) 1 dared suggest that a series of Romanian and Slavic terms referring to social and political organisation, specifically ban (1) 'master, local leader' and (2) 'coin, money' (2nd sense derived from the lst one),jupîn (formerly giupîn) 'a master', 'a master, a lord', cioban 'a shepherd', rather reflect a compact etymological group of Pre-Romance and Pre-Slavic origin (including cioban, incorrectly considered a Turkish influence, seemingly starting from the erroneous, but largely spread hypothesis that intervocalic -b- in Romanian would rather suggest a newer origin 1 ). To these, on another occasion, I added the form vătaf,vătah (also with parallels in some Slavic languages, Paliga 1996: 34-36) and on another occasion 1 analysed the form boier, also spread in many neighbouring languages, which has often been considered either of unknown origin or again of Turkic (not Turkish, i.e. Ottoman) origin (Paliga 1990; see also our main studies gathered together in a single volume, Paliga 1999).

Language Encounters across Time and Space: Studies in Language Contact (review)

Reviewed by: Language encounters across time and space: Studies in language contact ed. by Bernt Brendemoen, Elizabeth Lanza, Else Ryen Gary H. Toops Language encounters across time and space: Studies in language contact. Ed. by Bernt Brendemoen, Elizabeth Lanza, and Else Ryen. Oslo: Novus Press, 1999. Pp. 378. Since 1995 the Faculty of Arts at the University of Oslo has pursued a special project entitled Språkmøter (‘language encounters’). The 21 articles that comprise the present volume were originally papers read by Norwegian and other scholars at two symposia held in connection with the Språkmøter project at Bolkesjø, Norway, in November 1995 and at the Norwegian Institute in Rome in November 1996. [End Page 198] With the exception of three articles written in German, the volume is written in English. It is divided into four parts—‘Some theoretical perspectives and models’ (four articles), ‘Perspectives from migration and language contact’ (eight articles), ‘High variety in contact with a low variety’ (four articles), and ‘Language encounters from an historical perspective’ (five articles). A review of one article from each of the four parts (in sequential order) will suffice here to highlight the scope of this volume. In ‘The dynamics of code-copying in language encounters’ (37–62), Lars Johanson offers lucid explanations of various well-known language contact phenomena from the standpoint of the so-called code-copying framework, a descriptive linguistic apparatus that is reflected to varying degrees in most of the contributions to this volume. Rejecting the widely held notion of code-switching, Johanson explains that ‘the central concept of code-copying is that elements of one code are copied and the copies inserted into another code’ (39). In typical contact situations, either elements of a dominant language B2 are copied into a dominated native language A1 (constituting the matrix language or ‘model code’), or a community of A1 speakers copies elements of its native language into a dominant language B2 in the process of acquiring that language. In the latter situation, the target language (B2) functions as the model code, and the copying of A1 elements into B2 is viewed as a ‘substratum influence’ (42). In ‘Multilingualism in a Cameroonian village’ (195–203), Rolf Theil Endresen describes the complex sociolinguistic situation of the village of Galim in northern Cameroon. Endresen notes that relative to the size of its population, ‘Cameroon is more fragmented linguistically than any other country in the world except Papua New Guinea’ (197). Cameroon is also the only African country in which both French and English are official languages. French is the official language of that part of the country in which Galim is located although it is not the native language of any of the village’s inhabitants. The languages spoken in Galim include Fulani, Hausa, Nizaa, Vute, Kanuri, Mbum, and Chamba; together they represent five branches of three different language families (Afro-Asiatic, Nilo-Saharan, and Niger-Congo). Endresen observes that in Galim, Fulani serves as a lingua franca, which is learned as a second language by native speakers of Hausa, Nizaa, Mbum, Chamba, and Kanuri (to the extent that ethnic Kanuri do not already speak Fulani as a native language). In ‘Das Experiment des Ladin Dolomitan: Norm und Idiomvarianz’ (257–70), Ulrike Kindl describes the genesis and function of Ladin Dolomitan, a written language artificially created in 1994 to provide a single, supradialectal normative grammar, lexicon, and orthography for the roughly 20,000 speakers of Ladin dialects in the Dolomite valleys of northern Italy (southern Tyrol). The codification of Ladin Dolomitan was undertaken for the same basic purposes as that of Rumantsch Grischun (beginning in 1982) for the speakers of Rhaeto-Romanic dialects in Switzerland’s Graubünden (Grisons), viz., to serve both as a referential norm for native speakers and as a consolidated literary language that can be learned and used by nonnative speakers. Kindl points out, however, that the functional scope of Ladin Dolomitan remains highly restricted since most Ladinspeakers are accustomed to using Italian or German when communicating with people from outside the Ladin speech community of their respective valley. In ‘Der Einfluss...

Periphyton production on wood and sediment: substratum-specific response to laboratory and whole-lake nutrient manipulations

Substratum heterogeneity is a large source of variability in periphyton production, but the influence of substratum on periphyton response to experimental manipulations is rarely measured. Using laboratory and whole-lake experiments, we compared area-specific primary production of periphyton on wood (epixylon) and sediment (epipelon), and tested whether periphyton on the 2 substrata responded differently to water-column fertilization. In the laboratory, natural periphyton assemblages on wood or sediment were exposed to 1 of 6 treatments in a fully factorial (light [250, 70, or 10 μmol m−2 s−1] × nutrient [control or + N and P]) experiment. We measured 14C primary production on both substrata after 25 to 30 d. We also measured epipelic and epixylic production in a reference and an experimentally fertilized lake. We constructed photosynthesis-irradiance curves for epipelon from 3 depths in each lake, and used the curves to predict primary production at average in situ light intensities for each lake and depth.Production response to fertilization was substratum-specific, and area-specific epipelic production was 10× that of epixylon at both experimental scales. Both epixylon (ANOVA, p < 0.0001) and epipelon (ANOVA, p < 0.0001) production increased significantly with increasing light. Epixylon production was significantly higher in fertilized treatments than in controls (ANOVA, p < 0.01), but epipelon did not respond to fertilization (ANOVA, p = 0.69). Epixylon production was also significantly higher in the fertilized lake than in the reference lake (ANOVA, p < 0.05). Maximum epipelic production rates decreased with water depth in both lakes, and average epipelic production from both lakes was positively and similarly related to average in situ light intensities (linear regression, R2 = 0.94, p = 0.001). Both substratum-specific response to fertilization and substratum-specific periphyton production may be critical in determining fertilization-induced changes in periphyton production in lakes.

Management of Manila clam beds: I. Influence of seed size, type of substratum and protection on initial mortality

Commercial Manila clam beds in the Eo estuary (NW Spain) were studied from 1991 to 1996 to determine the influence of seed size, level of protection and substratum type on mortality early in the culture period. We detected a significant effect of size on mortality in both protected and unprotected beds, as, even with predator control, smaller seed showed poorer survival when planted in the field. A significant influence of substratum on mortality was also evident, with lowest mortality in sand–gravel beds. Clams reached a size-refuge at 1 g (16 mm in shell length) when protected with nets from predators and at 2 g (21 mm in length) when unprotected, showing how the net reduced the availability of clams to predators. Therefore, planting larger clams in sand–gravel beds and protecting them with nets will enhance clam survival.

Influence of laminin substratum on cell proliferation and CALC I gene expression in medullary thyroid carcinoma C cell lines

Medullary thyroid carcinoma (MTC) originates from C cells, which secrete calcitonin (CT) and CT gene-related peptide (CGRP), the two splice peptide products of the CALC I gene. Normal and hyperplastic C cells are intrafollicular, in contact with the basement membrane (BM) that is maintained around the differentiated tumors. To investigate the relationships between MTC evolution and BM constituents, we examined the modifications induced by laminin-1 and -2 (merosin), two isoforms colocalized in the follicular BM, on three MTC cell lines: murine rMTC 6-23 and CA-77 cells, and human TT cells. Laminin exerted a mitogenic activity on rMTC 6-23 and on TT cells, causing a concurrent decrease in both CT and CGRP mRNA levels and production of the peptides. Conversely, laminin reduced the proliferation rate and enhanced CGRP synthesis and secretion in CA-77 cells. This antiproliferative response, which coincides with an increase in differentiation markers, is comparable to that reported in normal cells and also in the neoplastic Caco-2 cell line. This suggests that laminin could exert opposite effects depending on the stage of tumor evolution.

Portuguese in Sri Lanka: influence of substratum languages

Sri Lanka Portuguese Creole is considered to fall within the group of Indo-Portuguese Creoles, which were Portuguese-based Creoles that once flourished around coastal India and Sri Lanka. Sri Lanka Portuguese Creole arose when the Portuguese established trading posts and fortresses in Sri Lanka from 1517 onwards. The purpose of this paper is to examine critically the influence of substratum (indigenous) languages on Sri Lanka Portuguese Creole.

Effects of substratum and conspecific adults on the metamorphosis of Chasmagnathus granulata (Dana) (Decapoda: Grapsidae) megalopae

The ability of marine invertebrate larvae to delay their metamorphosis in the absence of adequate environmental cues has been reported for numerous sedentary and sessile species. In the present study, the effect of various substrata and the presence of conspecific adults on the metamorphosis of a mobile species, the crab Chasmagnathus granulata, was evaluated. The duration of the megalopa stage in experiments with six different substrata and in the presence or absence of conspecific adults was compared in a laboratory study. In addition, the influence of natural substrata was compared with that of artificial substrata of similar grain size or texture. In a further experiment, the two most effective cues (natural mud and conspecific adults) were tested as single vs. combined factors. Natural mud and unidentified chemical cues from conspecific adults had the strongest accelerating effects on development duration to metamorphosis. With the exception of nylon threads (artificial filamentous substratum), none of the artificial substrata had a significant effect on the duration of the megalopa stage. Simultaneous exposure to natural mud and water containing chemical cues from conspecific adults accelerated metamorphosis more than each of these factors separately. Megalopae that were reared without a substratum (control) delayed their metamorphosis by 29% (about 3 days) compared with those in simultaneous contact with natural mud and rearing water of adult conspecifics. The results indicate that the metamorphosis of the megalopa of C. granulata is influenced by the presence or absence of environmental stimuli that are associated with the preferred adult habitat.