High frequency fire alters C:N:P stoichiometry in forest litter

Fire is a major driver of ecosystem change and can disproportionately affect the cycling of different nutrients. Thus, a stoichiometric approach to investigate the relationships between nutrient availability and microbial resource use during decomposition is likely to provide insight into the effects of fire on ecosystem functioning. We conducted a field litter bag experiment to investigate the long-term impact of repeated fire on the stoichiometry of leaf litter C, N and P pools, and nutrient-acquiring enzyme activities during decomposition in a wet sclerophyll eucalypt forest in Queensland, Australia. Fire frequency treatments have been maintained since 1972, including burning every two years (2yrB), burning every four years (4yrB) and no burning (NB). C:N ratios in freshly fallen litter were 29-42% higher and C:P ratios were 6-25% lower for 2yrB than NB during decomposition, with correspondingly lower 2yrB N:P ratios (27-32) than for NB (34-49). Trends in litter soluble and microbial N:P ratios were similar to the overall litter N:P ratios across fire treatments. Consistent with these, the ratio of activities for N-acquiring to P-acquiring enzymes in litter was higher for 2yrB than NB while 4yrB was generally intermediate between 2yrB and NB. Decomposition rates of freshly fallen litter were significantly lower for 2yrB (72±2% mass remaining at the end of experiment) than for 4yrB (59±3%) and NB (62±3%), a difference that may be related to effects of N limitation, lower moisture content, and/or litter C quality. Results for older mixed-age litter were similar to those for freshly fallen litter although treatment differences were less pronounced. Overall, these findings show that frequent fire (2yrB) decoupled N and P cycling, as manifested in litter C:N:P stoichiometry and in microbial biomass N:P ratio and enzymatic activities. These data indicate that fire induced a transient shift to N-limited ecosystem conditions during the post-fire recovery phase. This article is protected by copyright. All rights reserved.

Temporal and spatial patterns of soil water extraction and drought resistance among genotypes of a perennial C-4 grass

The objective of this study was to investigate patterns of soil water extraction and drought resistance among genotypes of bermudagrass (Cynodon spp.) a perennial C-4 grass. Four wild Australian ecotypes (1-1, 25a1, 40-1, and 81-1) and four cultivars (CT2, Grand Prix, Legend, and Wintergreen) were examined in field experiments with rainfall excluded to monitor soil water extraction at 30-190 cm depths. In the study we defined drought resistance as the ability to maintain green canopy cover under drought. The most drought resistant genotypes (40-1 and 25a1) maintained more green cover (55-85% vs 5-10%) during water deficit and extracted more soil water (120-160 mm vs 77-107 mm) than drought sensitive genotypes, especially at depths from 50 to 110 cm, though all genotypes extracted water to 190 cm. The maintenance of green cover and higher soil water extraction were associated with higher stomatal conductance, photosynthetic rate and relative water content. For all genotypes, the pattern of water use as a percentage of total water use was similar across depth and time We propose the observed genetic variation was related to different root characteristics (root length density, hydraulic conductivity, root activity) although shoot sensitivity to drying soil cannot be ruled out.

A quantum chemical investigation of the metal centres in cytochrome c oxidase

Quantum effects are often of key importance for the function of biological systems at molecular level. Cellular respiration, where energy is extracted from the reduction of molecular oxygen to water, is no exception. In this work, the end station of the electron transport chain in mitochondria, cytochrome c oxidase, is investigated using quantum chemical methodology. Cytochrome c oxidase contains two haems, haem a and haem a3. Haem a3, with its copper companion, CuB, is involved in the final reduction of oxygen into water. This binuclear centre receives the necessary electrons from haem a. Haem a, in turn, receives its electrons from a copper ion pair in the vicinity, called CuA. Density functional theory (DFT) has been used to clarify the charge and spin distributions of haem a, as well as changes in these during redox activity. Upon reduction, the added electron is shown to be evenly distributed over the entire haem structure, important for the accommodation of the prosthetic group within the protein. At the same time, the spin distribution of the open-shell oxidised state is more localised to the central iron. The exact spin density distribution has been disputed in the literature, however, different experiments indicating different distributions of the unpaired electron. The apparent contradiction is shown to be due to the false assumption of a unit amount of unpaired electron density; in fact, the oxidised state has about 1.3 unpaired electrons. The validity of the DFT results have been corroborated by wave function based coupled cluster calculations. Point charges, for use in classical force field based simulations, have been parameterised for the four metal centres, using a newly developed methodology. In the procedure, the subsystem for which point charges are to be obtained, is surrounded by an outer region, with the purpose of stabilising the inner region, both electronically and structurally. Finally, the possibility of vibrational promotion of the electron transfer step between haem a and a3 has been investigated. Calculating the full vibrational spectra, at DFT level, of a combined model of the two haems, revealed several normal modes that do shift electron density between the haems. The magnitude of the shift was found to be moderate, at most. The proposed mechanism could have an assisting role in the electron transfer, which still seems to be dominated by electron tunnelling.

20th Anniversary of the United Nations Decisions to Establish the State of Israel Commemorative Medal

Obverse: Portraits of A.H. Silver and Harry S. Truman. Reverse: Statue of Liberty to the right, emblem of the United Nations, menorah.

Conformation And C-N Rotational Barrier Of Dithiocarbamate Esters Nmr And Molecular-Orbital Studies

The variable temperature proton and ambient temperature carbon-13 NMR spectra of S-methyl dithiocarbamate esters have been recorded. The results of the theoretical energy calculations (CNDO/2 and EHT types) together with the experimental data have been interpreted in terms of the molecular conformations. The barrier heights for the rotation about the thioamide C—N bond are calculated using the CNDO/2 method and the results are discussed in terms of the computed charge densities and bond orders.

The Autobiography of a Jewish Refugee 1921-1998

Charles Leigh, 1992, 1994, 1999

The right path : The autobiography of a survivor /

Account of the German occupation of Kecskemet; fate of Jews of Kecskemet; liberation; immediate postwar experiences in Kecskemet; memories of childhood in Kotaj and Kecskemet; move to Budapest; training as soccer player in Budapest; return to Kecskemet and work in printing shop; fate of family members during the holocaust; early years of World War II in Kecskemet; entry into forced labor; life in labor camp; escape and hiding; liberation by Red Army; return to Kecskemet under Soviet Ukrainian occupation; return to printing business in Kecskemet; courtship and marriage in April 1945; reuinion with two sisters; birth of daugher; move to Budapest in 1949; work as printer in Budapest; life in Budapest under Communist domination; anti-Semitism; uprising of 1956 in Budapest; flight to Vienna; life in Vienna; emigration to USA; life in New York; move to Los Angeles; started business in food preparation; coached soccer team.

Lucien Wolf and David Mowshowitch papers, [ca. 1869-1959]

Correspondence, reports, minutes, manuscripts, and clippings relating to the activities of Wolf, Mowshowitch, and the Joint Foreign Committee, as well as to the political situation of Jews in various countries and to the Paris Peace Conference. Papers of Lucien Wolf include his diary, lectures on English-German relations and English-Russian relations; bibliography of Wolf's works on Jewish themes; clippings of Wolf's articles; congratulations on his seventieth birthday; article on his last interview with Chamberlain; and correspondence with parents, 1869-1882, A. Abrahams, 1914-1925, Chief Rabbi Dr. J.H. Hertz, 1892-1923, Clara Melchior, 1913-1929, Jacob Schiff, 1910, Maxim Vinawer, 1917, Mark Wischnitzer, 1926-1928, Lord Robert Cecil, 1916-1919, Lord Rothschild, 1906, Cyrus Adler, Count J. Bernstorff, Szymon Ashkenazy, Solomon Dingol, Louis Marshall, Claude G. Montefiore, Sir Edward Sassoon, Jacob Schiff, Lord William Selborne, Nakhum Sokolow, Oscar Straus, Chaim Weizmann, the American Jewish Congress, 1916-1923, Hilfsverein der Deutschen Juden, 1913, and Jewish Historical Society of England.

Genetic control of flowering in spotted gum, Corymbia citriodora subsp. variegata and C. maculata

Genetically controlled asynchrony in anthesis is an effective barrier to gene flow between planted and native forests. We investigated the degree of genetically controlled variation in the timing of key floral developmental stages in a major plantation species in subtropical Australia, Corymbia citriodora subsp. variegata K.D. Hill and L.A.S Johnson, and its relative C. maculata K.D. Hill and L.A.S. Johnson. Flowering observations were made in a common garden planting at Bonalbo in northern New South Wales in spring on 1855 trees from eight regions over three consecutive years, and monthly on a subset of 208 trees for 12 months. Peak anthesis time was stable over years and observations from translocated trees tended to be congruent with the observations in native stands, suggesting strong genetic control of anthesis time. A cluster of early flowering provenances was identified from the north-east of the Great Dividing Range. The recognition of a distinct flowering race from this region accorded well with earlier evidence of adaptive differentiation of populations from this region and geographically-structured genetic groupings in C. citriodora subsp. variegata. The early flowering northern race was more fecund, probably associated with its disease tolerance and greater vigour. Bud abundance fluctuated extensively at the regional level across 3 years suggesting bud abundance was more environmentally labile than timing of anthesis. Overall the level of flowering in the planted stand (age 12 years) was low (8–12% of assessed trees with open flowers), and was far lower than in nearby native stands. Low levels of flowering and asynchrony in peak anthesis between flowering races of C. citriodora subsp. variegata may partially mitigate a high likelihood of gene flow where the northern race is planted in the south of the species range neighbouring native stands

Hannah Ruth London papers, 1919-1990.

The collection consists primarily of research notes for Ms. London's published works on portraits, miniatures and silhouettes of American Jews. The notes contain family histories of the subjects as well as information on the artists, and are arranged both by subject and artist. The collection also contains published articles on the subject by London, and photographs and lantern slides of the artwork that have been removed to the picture collection.

Lt. Colonel Rachel (Rae) Diane Landy papers undated, 1913-2000

Rachel Diane Landy Papers consist of correspondence, reminiscences, legal documents, journal, newspaper and magazine articles and color Xerox copies of photographs as well as original photographs. This collection is of value to researchers studying the history of Hadassah and the living conditions and state of medical care in Palestine during the second decade of the 20th century. It is also of interest to researchers studying women in America during the first half of the 20th century who were able to pursue a challenging and productive career and become a leader and innovator in their chosen field. In addition it will be of interest to those researching the graduates of the Cleveland public and professional schools at the end of the 19th and beginning of the 20th centuries, and the Cleveland Jewish community and the George Crile U.S. Army Hospital in Cleveland during the 1940's.

American Jewish Committee. Office of Jewish War Records, undated, 1918-1921, 1962.

The records consist of documentation of the American Jewish Committee's project to describe Jewish participation in the United States Armed Forces during World War I. The bulk of the material consists of questionnaires that the AJC sent to servicemen to determine Jewish identity, which contain information on personal identification and details of military service. Responses to the questionnaire come from both Jews and non-Jews. In addition, the collection contains office papers concerning the project and a ledger of manuscripts. The manuscripts document the distribution of records the Office of Jewish War Records collected, as well as list Jews who died or were given military honors.

Raphael Lemkin collection undated, 1763, 1915-1919, [c.1921], 1933, 1941-1952, 1983, 1989.

Lemkin is the individual primarily responsible for adoption of the United Nations Convention for the Prevention and Punishment of Genocide. The collection is arranged according to the following subject areas: personal material, material on the Genocide Convention, material on genocide.

Bernard C. Ehrenreich papers undated, 1871-1971

Primarily correspondence, scrap-books, etc. relating to activities as rabbi in Montgomery, Alabama and Stockton, California. Includes also extensive correspondence from Jewish servicemen in World War I and II, Intercollegiate Menorah Association, Zeta Beta Tau Fraternity and Camp Kawaga and letters from Stephen S. Wise, Mordecai M. Kaplan and Leon J. Obermayer. Contains also collection of picture postal cards and original minute-book of the Central Bureau of the Federation of American Zionists of Greater New York.