N2O fluxes from the native and grazed semi-arid steppes and their driving factors in Inner Mongolia, China

This paper presents results of 2 years (from January 2005 to December 2006) of measurement of N2O fluxes from the native and grazed Leymus chinensis (LC) steppes in Inner Mongolia, China using the static opaque chamber method. The measurement was at a frequency of twice per month in the growing season and once per month in the non-growing season. In addition, the possible effect of water-heat factors on N2O fluxes was statistically analyzed. The results indicated that there were distinct seasonal patterns in N2O fluxes with large fluxes in spring, summer, and autumn but negative fluxes in winter. The annual net emission of N2O ranging from 0.24 to 0.30 kg N2O-N ha(-1) and from 0.06 to 0.26 kg N2O-N ha(-1) from the native and grazed LC steppe, respectively. Grazing activities suppressed N2O production. In the growing season, soil moisture was the primary driving factor of N2O fluxes. The high seasonal variation of N2O fluxes was regulated by the distribution of effective rainfall, rather than precipitation intensity. Air temperature or soil temperature at 0, 5, and 10 cm depth was the most restricting factor of N2O fluxes in the non-growing season.

Are the native giant tortoises from the Seychelles really extinct? A genetic perspective based on mtDNA and microsatellite data.

The extinction of the giant tortoises of the Seychelles Archipelago has long been suspected but is not beyond doubt. A recent morphological study of the giant tortoises of the western Indian Ocean concluded that specimens of two native Seychelles species survive in captivity today alongside giant tortoises of Aldabra, which are numerous in zoos as well as in the wild. This claim has been controversial because some of the morphological characters used to identify these species, several measures of carapace morphology, are reputed to be quite sensitive to captive conditions. Nonetheless, the potential survival of giant tortoise species previously thought extinct presents an exciting scenario for conservation. We used mitochondrial DNA sequences and nuclear microsatellites to examine the validity of the rediscovered species of Seychelles giant tortoises. Our results indicate that the morphotypes suspected to represent Seychelles species do not show levels of variation and genetic structuring consistent with long periods of reproductive isolation. We found no variation in the mitochondrial control region among 55 individuals examined and no genetic structuring in eight microsatellite loci, pointing to the survival of just a single lineage of Indian Ocean tortoises.

Predatory interactions between the invasive amphipod Gammarus tigrinus and the native opossum shrimp Mysis relicta

The invasive North American amphipod Gammarus tigrinus is successfully established in Lough Neagh, Northern Ireland. Gammarus tigrinus is increasingly recognized as having significant predatory impacts on macroinverebrates, contrary to the accepted functional feeding group status of Gammarus species. The native opossum shrimp Mysis relicta overlaps in habitat use with G. tigrinus. However, its interaction with benthic macroinvertebrates is rarely appreciated. Mutual predatory interactions between G. tigrinus and M. relicta were assessed in a series of laboratory experiments. Gammarus tigrinus actively preyed on adult and juvenile M. relicta at a range of spatial scales. Females and recently molted M. relicta were particularly vulnerable to predation. Mysis relicta did not prey on adult G. tigrinus, but rapidly eliminated juvenile G. tigrinus in microcosms. Changes in dissolved 02 saturation did not alter the predatory interaction between these species. Microhabitat use by M. relicta was altered in the presence of G. tigrinus, and the presence of G. tigrinus facilitated fish predation on M. relicta. A balance of mutual predatory pressure between these invasive and native species may explain their coexistence. Both species are likely to be strongly interactive with other macroinvertebrates in both native and invasive ranges.

Evaluation of neuroprotective potential of plyphenols derived from Portuguese native plants: Juniperus sp. and Rubus sp.

Dissertation presented to obtain the Ph.D degree in Biochemistry

Formal garden of Charles C. Chapman, Fullerton, California, 1914

Formal garden of Charles C. Chapman, Fullerton, California. Photograph taken on day of garden party, September 5, 1914.

Unidentified man on the campus of California Christian College, Los Angeles

Unidentified man in cap and gown on the campus of California Christian College, Los Angeles, in the 1920s.

Davis Community Center and Apartments, Chapman College, Orange, California

Davis Community Center and Apartments opened September, 1974 at 625 North Grand Street, Orange, California, named in honor of Chapman College's fourth president, Dr. John L. Davis. The five two-story apartment buildings were designed by Harold Gimeno & Associates of Santa Ana and built by the J. Ray Construction Company, Inc. of Costa Mesa.

Davis Community Center and Apartments, Chapman College, Orange, California

Davis Community Center and Apartments opened September, 1974, at 625 North Grand Street, Orange, California, named in honor of Chapman College's fourth president, Dr. John L. Davis. The five two-story apartment buildings were designed by Harold Gimeno & Associates of Santa Ana and built by the J. Ray Construction Company, Inc. of Costa Mesa.

Davis Community Center and Apartments, Chapman College, Orange, California

Davis Community Center and Apartments opened September, 1974 at 625 North Grand Street, Orange, California, named in honor of Chapman College's fourth president, Dr. John L. Davis. The five two-story apartment buildings were designed by Harold Gimeno & Associates of Santa Ana and built by the J. Ray Construction Company, Inc. of Costa Mesa.

Davis Community Center and Apartments, Chapman College, Orange, California

Davis Community Center and Apartments opened September, 1974, at 625 North Grand Street, Orange, California, named in honor of Chapman College's fourth president, Dr. John L. Davis. The five two-story apartment buildings were designed by Harold Gimeno & Associates of Santa Ana and built by the J. Ray Construction Company, Inc. of Costa Mesa.

Davis Community Center and Apartments, Chapman College, Orange, California

Davis Community Center and Apartments opened September, 1974, at 625 North Grand Street, Orange, California, named in honor of Chapman College's fourth president, Dr. John L. Davis. The five two-story apartment buildings were designed by Harold Gimeno & Associates of Santa Ana and built by the J. Ray Construction Company, Inc. of Costa Mesa.

Davis Community Center and Apartments, Chapman College, Orange, California

Davis Community Center and Apartments opened September, 1974, at 625 North Grand Street, Orange, California, named in honor of Chapman College's fourth president, Dr. John L. Davis. The five two-story apartment buildings were designed by Harold Gimeno & Associates of Santa Ana and built by the J. Ray Construction Company, Inc. of Costa Mesa.

Davis Community Center and Apartments, Chapman College, Orange, Calfornia

Davis Community Center and Apartments opened September, 1974, at 625 North Grand Street, Orange, California, named in honor of Chapman College's fourth president, Dr. John L. Davis. The five two-story apartment buildings were designed by Harold Gimeno & Associates of Santa Ana and built by the J. Ray Construction Company, Inc. of Costa Mesa.

Davis Community Center and Apartments, Chapman College, Orange, California

Davis Community Center and Apartments opened September, 1974, at 625 North Grand Street, Orange, California, named in honor of Chapman College's fourth president, Dr. John L. Davis. The five two-story apartment buildings were designed by Harold Gimeno & Associates of Santa Ana and built by the J. Ray Construction Company, Inc. of Costa Mesa.

Davis Community Center and Apartments, Chapman College, Orange, California

Davis Community Center and Apartments opened September, 1974, at 625 North Grand Street, Orange, California, named in honor of Chapman College's fourth president, Dr. John L. Davis. The five two-story apartment buildings were designed by Harold Gimeno & Associates of Santa Ana and built by the J. Ray Construction Company, Inc. of Costa Mesa.