Management of Pigs Prior To and Immediately Following Weaning at Four Weeks of Age

Baby pig management at weaning remains the weak link in most swine operations. The pig\u27s management requirements remain as high at this stage of growth as they are when the pigs are on the show. Stress from improper nutrition, housing, temperature and ventilation as well as from establishing a new social order among regrouped pigs may affect performance and health problems of this young pig. Much is still to be learned about proper management which will minimize stress. South Dakota State University is cooperating with out Land Grant colleges in the North Central Region to evaluate the practice of intermingling litters prior to weaning to learn if the stress of weaning can be reduced the data presented herein are the results of the first trial

Effects of Dietary Protein, Calcium, and Phosphorus in Pig Starter Diets

The study reported herein was designed to determine the effect of dietary protein levels and varying levels of calcium and phosphorus on performance of early weaned pigs

The lichens of Moshchny Islannd (Lavansaari) - one of the remote islands in the Gulf of Finland.

Peer reviewe

Root hairs

Roots hairs are cylindrical extensions of root epidermal cells that are important for acquisition of nutrients, microbe interactions, and plant anchorage. The molecular mechanisms involved in the specification, differentiation, and physiology of root hairs in Arabidopsis are reviewed here. Root hair specification in Arabidopsis is determined by position-dependent signaling and molecular feedback loops causing differential accumulation of a WD-bHLH-Myb transcriptional complex. The initiation of root hairs is dependent on the RHD6 bHLH gene family and auxin to define the site of outgrowth. Root hair elongation relies on polarized cell expansion at the growing tip, which involves multiple integrated processes including cell secretion, endomembrane trafficking, cytoskeletal organization, and cell wall modifications. The study of root hair biology in Arabidopsis has provided a model cell type for insights into many aspects of plant development and cell biology

Additions to the lichen biota of Berezovye Islands, Leningrad Region, Russia

66 species of lichens, 9 lichenicolous fungi and 4 non-lichenized saprobic fungi are reported as new to the Berezovye Islands (Leningrad Region, Russia). The updated lichen biota of the archipelago comprises 356 species. Caloplaca maritima, Lecanora compallens, Verrucaria boblensis and Xanthoriicola physciae are reported for the first time for Russia, Lecanora aitema – for European Russia, Lecanora semipallida and Lichenodiplis lecanorae – for North-Western European Russia. Absconditella sphagnorum, Chaenothecopsis vainioana, Lempholemma polyanthes and Opegrapha niveoatra are new to the Leningrad Region, Arthonia byssacea and Lecanora subrugosa – to the Western Leningrad Region.

Calcium influx at the tip of growing root-hair cells of Arabidopsis thaliana

The role of extracellular Ca 2+ in root-hair tip growth has been investigated in Arabidopsis thaliana (L.) Heynh. Root-hair length was found to be dependent on the concentration of Ca 2+ in the growth medium, with maximum length achieved at [Ca 2+ ] of 0.3–3.0 mM. Using a non-intrusive calcium-specific vibrating microelectrode, an extracellular Ca 2+ gradient was detected at the tips of individual growing root-hair cells. The direction of the gradient indicated a net influx of Ca 2+ into root-hair cells. No gradient was detected near the sides of the root hairs or at the tips of non-growing root hairs. When root hairs were exposed to the Ca 2+ -channel blocker nifedipine, tip growth stopped and the extracellular Ca 2+ gradient was abolished. These results indicate that Ca 2+ influx through plasma-membrane Ca 2+ channels is required for normal root-hair tip growth.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47478/1/425_2004_Article_BF00199963.pd

Growth and ultrastructure of Arabidopsis root hairs: the rhd3 mutation alters vacuole enlargement and tip growth

The root hairs of plants are tubular projections of root epidermal cells and are suitable for investigating the control of cellular morphogenesis. In wild-type Arabidopsis thaliana (L.) Heynh, growing root hairs were found to exhibit cellular expansion limited to the apical end of the cell, a polarized distribution of organelles in the cytoplasm, and vesicles of several types located near the growing tip. The rhd3 mutant produces short and wavy root hairs with an average volume less than one-third of the wild-type hairs, indicating abnormal cell expansion. The mutant hairs display a striking reduction in vacuole size and a corresponding increase in the relative proportion of cytoplasm throughout hair development. Bead-labeling experiments and ultrastructural analyses indicate that the wavy-hair phenotype of the mutant is caused by asymmetric tip growth, possibly due to abnormally distributed vesicles in cortical areas flanking the hair tips. It is suggested that a major effect of the rhd3 mutation is to inhibit vacuole enlargement which normally accompanies root hair cell expansion.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47482/1/425_2005_Article_BF01007706.pd