Local grassland restoration affects insect communities

1. It is hypothesised that ecological restoration in grasslands can induce an alternative stable state shift in vegetation. The change in vegetation influences insect community assemblages and allows for greater functional redundancy in pollination and refuge for native insect species. 2. Insect community assemblages at eight coastal California grassland sites were evaluated. Half of these sites had undergone restoration through active revegetation of native grassland flora and half were non‐restored. Insects were collected from Lupinus bicolor (Fabaceae) within 2 × 2‐m² plots in spring 2017. Lupinus bicolor is a common native species that is used in California restoration projects, and home and state landscaping projects. 3. Ordination demonstrated that insect community assemblages were different between restored and non‐restored sites. These differences were seen in insect functional groups as well as taxa‐specific differences and were found to be driven by environmental characteristics such as non‐native forb cover. 4. Functional redundancy of herbivores decreased at restored sites, while pollinators became more redundant compared with non‐restored sites. The assemblages of the common species found at restoration sites contained more native insects than those found at non‐restored sites, including species such as Bombus vosnesenskii. 5. Local grassland restoration has the potential to induce an alternative stable state change and affect insect community assemblages. Additionally, it was found that grassland restoration can be a potential conservation tool to provide refugia for bumblebees (Bombus), but additional studies are required to fully understand its broader applicability.     

Bacteriophage-resistance mechanisms examined by transfection of Lactococcus lactis subsp. lactis 4513-5 mediated by high voltage electroporation

Summary Phage adsorption tests and transfection by electroporation were carried out to decide whether phage-resistance in Lactococcus lactis subsp. lactis strain 4513-5 is based on intracellular or extracellular mechanisms. Using high voltage (12.5 kV/cm) electroporation, untreated phage DNA was introduced into phage-sensitive and phage-resistant cells. Since phages showed low adsorption frequencies on resistant bacteria, resistance is localized in the cell wall preventing phage DNA from entering the cell. This is the only mechanism responsible for the resistance of L. lactis subsp. lactis 4513-5 against its homologous phage P4513-K12 and non-homologous phages P05M-13 and P05M-47, but not against phage P530-7 and phage P530-12. In the case of the latter two phage strains, intracellular resistance mechanisms are involved and discussed.     

Family organization and the wage labor transition in a Tamang community of Nepal

This paper explores familial contexts of transition to a wage labor economy using ethnographic and survey data from Tamang communities at the northern edge of Nepal's Kathmandu Valley. Historically agro-pastoralist, the Tamang of this area have experienced social watersheds drawing them into ever closer relationships with Kathmandu. The earliest was their nineteenth century induction into corvée labor for national elites; more recent has been the accelerating monetization of the twentieth century. This analysis demonstrates trends and frames hypotheses about the social structuring of this latest process, testing them at the individual level with combined ethnographic and survey data from 1028 respondents. Multivariate analyses explore the effects of birth cohort, education, domestic group status, and settlement location on participation in non-family organized wage work. Substantive findings are related to the broader historical literature on household and family with special attention to varieties of subsistence to monetized transition.     

Habitat and population size of the coelacanth Latimeria chalumnae at Grand Comoro

Synopsis In 1987 and 1989 coelacanths were observed for the first time in their natural habitat with the help of submersibles. Coelacanths were found between 150–253 m depth, their preferential depth seems to be around 200 m; the water temperature ranged between 16.5–22.8° C. During the day coelacanths aggregate in small non-aggressive groups in sheltered lava-caves. Caves might be a limiting factor for distribution. At night they leave the caves for hunting by drifting singly along the steep lava slopes. They migrate between different caves located within a large home range covering more than 8 km coastline. Coelacanths are site-attached, some for a period of at least 2 years. Our own observations and earlier catch records show that only the west coast of Grand Comoro is a suitable coelacanth habitat with more structural complexity and prey fish abundance than other coastlines of the island. From our survey we estimated a total coelacanth population off Grand Comoro to be 150–210 individuals; a saturated population would be 370–510 individuals. This small relict population seems to be stable. International protection of coelacanths against commercial interests is needed     

The nervous system of Tricladida. III. Neuroanatomy ofDendrocoelum lacteum andPolycelis tenuis (Plathelminthes,Paludicola): an immunocytochemical study

The organization of the nervous system ofDendrocoelum lacteum (Tricladida, Paludicola, Dendrocelidae) andPolycelis tenuis (Tricladida, Paludicola, Planariidae) was studied by immunocytochemical double staining, using neuropeptide RFamide and serotonin (5-HT) antisera on cryosections. The study confirmed the status of the main nerve cords (MCs) as the most important and stable of the longitudinal cords and supported the hypothesis of a common phylogenetic origin of the MCs in flatworms. The ganglion-like structures along the MCs at the beginning of transverse commissures and laterla branches showed a close contact with ventral fibres of the submuscular nerve plexus indicating an origin from crossing points of insunken ring commissures. The distributional pattern and morphology of the RFamide-IR cell bodies inD. lacteum corresponded to that of neurosecretory cells. Most RFamide-IR cells were unipolar and rounded while 5-HT-IR cells were uni- bi- and multipolar. The neutropile consisted of a dense RFamide-IR and a loose 5-HT-IR network. RFamide dominated in all parts of the genital plexus.     

Significance of Ca2+ and K+ in Micrasterias Growth and Morphogenesis

Significance of Ca²⁺ and K⁺ for the complex morphogenesis ofMicrasterias, which takes place through multipolar tip growth,was investigated. Studies with different external Ca²⁺ concentrationsand Ca²⁺ channel inhibitors LaCl₃ and verapamil indicate thatCa²⁺ and Ca²⁺ channels are essential in the development, whiletreatments with different K⁺ concentrations and K⁺ channel inhibitorTEA demonstrate that potassium or K⁺ channels are not neededin the process, albeit the existence of K⁺ channels. K⁺ is notneeded even for the regulation of turgor pressure, which wasfound to decrease clearly during cell development. The plasmamembrane ATPase inhibitors diethylstilbesterol (DES) and Na-orthovanadatestop morphogenesis and indicate the importance of ion pumpsin the developmental process. Both supraoptimal, external K⁺and Ca²⁺ cause abundant Ca²⁺ precipitate formation in chloroplasts,which shows that chloroplasts are important in regulation ofcytoplasmic Ca²⁺ metabolism and that K⁺ activates the uptakeof Ca²⁺ through Ca²⁺ channels. (Received June 13, 1995; Accepted September 13, 1996)