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Overall benthic macroinvertebrate biodiversity, along with laternulid density, was higher closer to mangroves but relative infaunal invertebrate dominance increased along a transect that transcended a hummock closer to the mangrove forest, across an open sand fl at, and terminated in another isolated humMock farther from the fringing forest. A population of the anomalodesmatan bivalve Laternula truncata (Lamarck, 1818) was examined in a mangrove sand fl at in Kungkrabaen Bay, Thailand, to determine population size, cohort distribution, and basic relationships with sediment and infaunal macroinvertebrate biodiversity. Relatively high densities of L. truncata were found in muddy sands, often deeply buried in or close to tangled rootlet mats of the mangrove trees Avicennia alba Blume, 1827, and A. marina (Forsskal) Vierhapper, 1907, along isolated mangrove hummocks. They were less common in open areas of the mangrove fl at. This population of L. truncata was relatively evenly distributed across size classes, minus the smallest sizes, suggesting continuous recruitment with a possible loss of recent recruits or recruitment. Overall benthic macroinvertebrate biodiversity, along with laternulid density, was higher closer to mangroves but relative infaunal invertebrate dominance increased along a transect that transcended a hummock closer to the mangrove forest, across an open sand fl at, and terminated in another isolated hummock farther from the fringing forest. A nearby population of L. cf. corrugata (Reeve, 1863) inhabited a distinctly different habitat. Laternula cf. corrugata was shallowly buried and dwelt in the mangrove forest proper among different species of mangroves and in sandier sediments. Behavioural observations of both laternulids indicated that both were capable of reburying, with smaller specimens more rapidly, albeit still slowly, succeeding in full re-entry into the sediment. Larger specimens of L. truncata were incapable of reburial. Morphological, ecological, and behavioural distinctions between L. truncata and L. cf. corrugata are considered in light of their habitat differences, confusion within laternulid systematics, and diffi culty in resolving the taxonomy of the latter species.

Barbour's Pond is a 4.45-ha pond located in Garrett Mountain Reservation in Passaic County in northern New Jersey, one of the most densely populated regions in the United States. Despite its small size and surrounding urban sprawl, the shallow waters of this pond hold 18 species of molluscs. Monthly samples from March 2004 through March 2006 found the highest diversity in December 2004, and in January, June, and July 2005. Additional samples were taken in April 2007 and May 2010 to spot-check relative diversity years after the original sampling period. Total molluscan abundance was greatest in July and November 2004, possibly reflecting new late spring and autumn cohorts. Univariate statistics demonstrate that this pond has a temporally stable and diverse malacofauna. Analysis, of basic environmental parameters including temperature and pH, however, showed little correlation with molluscan diversity over time, underscoring the stable yet complex nature of biodiversity of this small urban pond.

Temperature is a determinant environmental variable in metabolic rates of organisms ultimately influencing important physiological and behavioural features. Stressful conditions such as increasing temperature, particularly within high ranges occurring in the summer, have been suggested to induce flotation behaviour in Corbicula fluminea which may be important in dispersal of this invasive species. However, there has been no experimental evidence supporting this hypothesis. It was already proven that C. fluminea drift is supported by a mucilaginous drogue line produced by mucocytes present in the ctenidia. Detailed microscopic examination of changes in these cells and quantification of clam flotation following one, two and three weeks of exposure to 22, 25 and 30°C was carried out so that the effects of increasing water temperatures in dispersal patterns could be discussed. Results show that changes in temperature triggered an acceleration of the mucocytes production and stimulated flotation behaviour, especially following one week of exposure. Dilution of these effects occurred following longer exposure periods. It is possible that these bivalves perceive changing temperature as a stress and respond accordingly in the short-term, and then acclimate to the new environmental conditions. The response patterns suggest that increasing water temperatures could stimulate C. fluminea population expansion.

The Asian isopod Ianiropsis serricaudis is now well established in fouling communities, often associated with introduced ascidians, throughout the Northern Hemisphere but has gone largely unnoticed because of its diminutive size (typically less than 3 mm in length) and the difficulties of identifying small peracarid crustaceans. Known locations include the northeastern Pacific (Puget Sound, San Francisco Bay, and Monterey Bay), the northwestern Atlantic (from the Gulf of Maine to Barnegat Bay, NJ), and the northeastern Atlantic (England and the Netherlands). We predict that this species is widespread along North America and European coasts, and may already be introduced to cold temperate waters of the Southern Hemisphere as well.

The anomalodesmatan family Laternulidae represents a group of bivalves with a very few well-known taxa and many more poorly known taxa. Laternula rostrata (G. B. Sowerby, 1839) and L. anatina (Linnaeus, 1758) occur in close proximity to each other in and along the margins of mangroves of Kungkrabaen Bay, Thailand. Laternula rostrata resides in soft to sandy sediments often within the interstices of mangrove roots located in more open portions of the mangrove mud flat. Laternula anatina lives deeper in the mangrove in more protected environs. Laternula anatina is a smaller bivalve that has a variable shell outline, sometimes a wrinkled shell appearance, thicker periostracum, and frequently extensive umbonal erosion. Both species have high concentrations of external shell spinules anteriorly and closer to the umbos (i.e., in juvenile shell) reflecting functionality in retaining an infaunal position. The larger L. rostrata is thinner shelled and more fragile; has more distinct and longer shell spinules composed of flattened lathes; a glossy external appearance; a longer umbonal slit; and a deeper pallial sinus. Additionally, L. rostrata has a saddle-shaped lithodesma; a lithodesma is absent in L. anatina as is typical of most laternulids. Shell microstructure of both is prismatonacreous, typical of the group, but the prismatic layer is thin and appears truncated into small blocky and/or granular columns in transitional zones. The bulk of the shell is tightly packed sheet nacre. The growth lines in L. rostrata, more pronounced but fewer in number than in L. anatina, appear as shallow rolling “hills” in both the shell and chondrophore. The differences in shell microstructure in these two species are specific to the taxa but based on different habitats and burrowing depths, albeit within the confines of a tropical mangal, could represent biomineralization events that reflect environmental adaptations. Variations in the thickness of the microstructural shell layers of four species of laternulids is compared and we speculate on possible functional and/or environmental relevance of these differences.

Diphenhydramine HCl (DH) and caffeine are commonly detected contaminants in waterways and drinking water nationwide (U.S.A.) and yet little is known of their influence on the development of aquatic molluscs. The antihistamine diphenhydramine blocks the chemical effects of histamine by inhibiting the re-uptake of serotonin (5-HT). Caffeine can influence the regulation of calcium (Ca2 ) and neurotransmitters, such as 5- HT, by inhibiting the re-uptake of adenosine. Serotonin receptor-mediated signaling is key during embryonic development in the freshwater snail Helisoma trivolvis (Say 1816). Embryonic development rates of H. trivolvis depend upon external conditions such as oxygen concentration and temperature. We examine the effects of diphenhydramine (DH) and caffeine on development and reproductive potential of this common aquatic snail. Concentrations of DH at 40.0, 50.0 and 60.0 µM affect the in-capsule embryonic development and hatching rate. Caffeine at 40.0, 50.0 and 60.0 µM show no influence to the hatching rates; however, these caffeine concentrations influence the in-capsule embryonic rotation rate. Eight-month observations of adult H. trivolvis reproductive activities show no influence in number of egg masses deposited when exposed to test concentrations of DH or caffeine.

Participants of New England town meeting must follow protocols to participate in this direct democratic process. Over the past 200 years, the protocols have been enacted and adapted by participants in small towns across the region. Within annual meetings, one can find small breaches that could be interpreted as playful acts. In this paper, we use the comic frame as a theoretical lens to interpret instances of such play within the rhetorical deliberation of one New England town meeting. We analyze two instances where speakers playfully use recognized parts of town meeting to achieve their rhetorical ends. We conclude with a discussion of the way play can help accomplish identification in public discourse.

Nursing students entering psychiatric settings for clinical practice need a solid foundation of therapeutic communication skills. This article presents an innovative strategy for nursing students to practice therapeutic communication skills with psychiatric patients by using hi fidelity simulation with Laerdal SimMan. Using the SimMan vocal function enabled nurse educators to develop communication algorithms that allowed students to interact with SimMan as they would with psychiatric patients. The SimMan algorithms can be designed to mimic many scenarios typically found in psychiatric settings. Nursing students can use this technology to take the therapeutic communication skills they have learned in the classroom and practice them in a safe laboratory environment before entering actual psychiatric settings. The ability of students to practice communication skills prior to entering psychiatric settings can promote effective therapeutic communication skills and decrease student anxiety. Copyright ©2008 The Berkeley Electronic Press. All rights reserved.

Freshwater unionid mussels produce a bilayered shell with the mineral proportion comprising an outer prismatic and an inner nacreous layer. The shell is the animals’ primary structural means of protection from predators and environmental challenges; therefore, variations in shell strength and properties may lead to differences in survival. Few studies have systematically assessed shell properties in unionids. A major challenge in such work is separating effects of environment from those of evolutionary history, because ultimately, both can affect shell properties. We collected eight species of unionids within a small area of the Allegheny River, Pennsylvania, that was relatively homogeneous in substratum type and other environmental characteristics. For each species, we quantified shell thickness, including thickness of the prismatic and nacreous layers, and shell micromechanical properties (microhardness and crack propagation, a measure of fracture resistance) in three regions of the shell. Shell thickness varied dramatically among species and was about five times greater in the thickest-shelled species, Pleurobema sintoxia, than in the thinnest-shelled species, Villosa iris. Because all species experienced similar environmental conditions, variation in shell thickness can be attributed largely to evolutionary history. In contrast, microhardness and crack propagation showed little variation among species. Given that micromechanical properties are similar among species, shell strength may be largely a function of thickness. These results have conservation implications, as differences in shell thickness could reflect relative vulnerability to predators and physical conditions

The organic component of the molluscan shell allows for orderly biomineralization and ensures structural integrity that is crucial to survival. This organic contribution to the shell typically composes 2-5% of the total adult shell by weight. Because macro- and microstructure of the shell is known to vary with ontogeny and across taxa, we examined if the organic to mineral ratio components in shell also varied with growth across taxa. To assess intraspecific differences in the organic to mineral ratio of the shell during growth, we examined ratios in three marine [Crepidula fornicata (Linnaeus, 1758), Littorina littorea (Linnaeus, 1758), and Littorina saxatilis (Olivi, 1792)] and two freshwater [Corbicula fluminea (Müller, 1774) and Bellamya chinensis (Gray, 1834)] mollusks across size ranges. In the marine gastropods, the average organic component by weight of the small size class was significantly larger than the average organic proportions of the medium and large size classes. The smallest size class of L. saxatilis had an average shell organic proportion of 11.12%, while the smallest size classes of C. fornicata (3.53%) and L. littorea (2.60%) had percentages below 5%. The smallest size class of C. fluminea had a greater average shell organic proportion than the largest size class (6.19% vs 2.68% organics). Adult specimens of B. chinensis had an average shell organic proportion of 3.93%, while in utero shelled juveniles had an average of 10.05%. In both freshwater and marine species, the smallest size class had a greater organic proportion. As the organic matrix is energetically more expensive than the calcified shell portion, we hypothesize that energy expended in these smaller (usually pre-reproductive maturity) stages of growth allows for a more rapid production of shell and that this “expense” is a valuable trade-off for the protection the shell offers young mollusks.

Communication researchers have used speech codes theory to interpret local conduct. This qualitative meta-analysis draws upon twenty years of peer-reviewed journal articles and books (2000–2019) that specifically use the concept of speech community within research about speech codes. Although speech community is incorporated into one of the six main tenets of speech codes theory, the concept has not been used consistently. After reviewing how speech codes theory researchers use the concept of speech community, I draw comparisons between those who describe mediated and intercultural practices to interrogate the a priori assertion of a speech community. I conclude by arguing that one must understand the particular social relations among speakers before asserting the existence of a speech community. © 2021 International Communication Association.