Ecoregional Analysis of Nearshore Sea-Surface Temperature in the North Pacific

The quantification and description of sea surface temperature (SST) is critically important because it can influence the distribution, migration, and invasion of marine species; furthermore, SSTs are expected to be affected by climate change. To better understand present temperature regimes, we assembled a 29-year nearshore time series of mean monthly SSTs along the North Pacific coastline using remotely-sensed satellite data collected with the Advanced Very High Resolution Radiometer (AVHRR) instrument. We then used the dataset to describe nearshore (<20 km offshore) SST patterns of 16 North Pacific ecoregions delineated by the Marine Ecoregions of the World (MEOW) hierarchical schema. Annual mean temperature varied from 3.8°C along the Kamchatka ecoregion to 24.8°C in the Cortezian ecoregion. There are smaller annual ranges and less variability in SST in the Northeast Pacific relative to the Northwest Pacific. Within the 16 ecoregions, 31–94% of the variance in SST is explained by the annual cycle, with the annual cycle explaining the least variation in the Northern California ecoregion and the most variation in the Yellow Sea ecoregion. Clustering on mean monthly SSTs of each ecoregion showed a clear break between the ecoregions within the Warm and Cold Temperate provinces of the MEOW schema, though several of the ecoregions contained within the provinces did not show a significant difference in mean seasonal temperature patterns. Comparison of these temperature patterns shared some similarities and differences with previous biogeographic classifications and the Large Marine Ecosystems (LMEs). Finally, we provide a web link to the processed data for use by other researchers

Giardia Flagellar Motility Is Not Directly Required to Maintain Attachment to Surfaces

Giardia trophozoites attach to the intestinal microvilli (or inert surfaces) using an undefined “suction-based” mechanism, and remain attached during cell division to avoid peristalsis. Flagellar motility is a key factor in Giardia's pathogenesis and colonization of the host small intestine. Specifically, the beating of the ventral flagella, one of four pairs of motile flagella, has been proposed to generate a hydrodynamic force that results in suction-based attachment via the adjacent ventral disc. We aimed to test this prevailing “hydrodynamic model” of attachment mediated by flagellar motility. We defined four distinct stages of attachment by assessing surface contacts of the trophozoite with the substrate during attachment using TIRF microscopy (TIRFM). The lateral crest of the ventral disc forms a continuous perimeter seal with the substrate, a cytological indication that trophozoites are fully attached. Using trophozoites with two types of molecularly engineered defects in flagellar beating, we determined that neither ventral flagellar beating, nor any flagellar beating, is necessary for the maintenance of attachment. Following a morpholino-based knockdown of PF16, a central pair protein, both the beating and morphology of flagella were defective, but trophozoites could still initiate proper surface contacts as seen using TIRFM and could maintain attachment in several biophysical assays. Trophozoites with impaired motility were able to attach as well as motile cells. We also generated a strain with defects in the ventral flagellar waveform by overexpressing a dominant negative form of alpha2-annexin::GFP (D122A, D275A). This dominant negative alpha2-annexin strain could initiate attachment and had only a slight decrease in the ability to withstand normal and shear forces. The time needed for attachment did increase in trophozoites with overall defective flagellar beating, however. Thus while not directly required for attachment, flagellar motility is important for positioning and orienting trophozoites prior to attachment. Drugs affecting flagellar motility may result in lower levels of attachment by indirectly limiting the number of parasites that can position the ventral disc properly against a surface and against peristaltic flow

Exchange hazards, relational reliability, and contracts in China: The contingent role of legal enforceability

Building on institutional and transaction cost economics, this article proposes that legal enforceability increases the use of contract over relational reliability (e.g., beliefs that the other party acts in a non-opportunistic manner) to safeguard market exchanges characterized by non-trivial hazards. The results of 399 buyer-supplier exchanges in China show that: (1) when managers perceive that the legal system can protect their firm's interests, they tend to use explicit contracts rather than relational reliability to safeguard transactions involving risks (i.e., asset specificity, environmental uncertainty, and behavioral uncertainty); and (2) when managers do not perceive the legal system as credible, they are less likely to use contracts, and instead rely on relational reliability to safeguard transactions associated with specialized assets and environmental uncertainty, but not those involving behavioral uncertainty. We further find that legal enforceability does not moderate the effect of relational reliability on contracts, but does weaken the effect of contracts on relational reliability. These results endorse the importance of prior experience (e.g., relational reliability) in supporting the use of explicit contracts, and alternatively suggest that, under conditions of greater legal enforceability, the contract signals less regarding one's intention to be trustworthy but more about the efficacy of sanctions. © 2010 Academy of International Business All rights reserved.postprin

Ritual plants of Muslim graveyards in northern Israel

This article surveys the botanical composition of 40 Muslim graveyards in northern Israel, accompanied by an ethnobotanical study of the folkloristic traditions of the use of these plants in cemeteries. Three groups of plants were found to be repeated systematically and were also recognized for their ritual importance: aromatics herbs (especially Salvia fruticosa and Rosmarinus officinalis), white flowered plants (mainly Narcissus tazetta, Urginea maritima, Iris spp. and Pancratium spp.) and Cupressus sempervirens as the leading cemetery tree. As endemic use we can indicate the essential role of S. fruticosa as the main plant used in all human rites of passage symbolizing the human life cycle. The rosemary is of European origin while the use of basil is of Indian influence. The use of white flowers as cemeteries plants reflects an old European influence and almost the same species are used or their congeners. Most of the trees and shrubs that are planted in Muslim cemeteries in Israel have the same use in ancient as well in modern European cultures. In conclusion, our findings on the occurrence of plants in graveyards reflect the geographic situation of Israel as a crossroads in the cultural arena between Asia and Europe. Most of the traditions are common to the whole Middle East showing high relatedness to the classical world as well as to the present-day Europe