Hopped Beer: The Case For Cultivation

The history of hops, hopped beer, and hop cultivation is unclear and ambiguous. An assessment of the available literature reveals many contradictions, especially regarding the first use of hops in beer and the earliest incidence of hop cultivation. Historically, hops were used for a variety of purposes; now their primary use is as a preservative and flavoring in beer. Hop cultivation is poorly documented, but was certainly undertaken by the 10th century, most probably in response to the demand generated by beer-brewing. After comparing the literature and investigating source material, a chronology of hop use in beer and hop cultivation is proposed.     

Evolutionary relationships of bacterial and archaeal glutamine synthetase genes

Glutamine synthetase (GS), an essential enzyme in ammonia assimilation and glutamine biosynthesis, has three distinctive types: GSI, GSII and GSIII. Genes for GSI have been found only in bacteria (eubacteria) and archaea (archaebacteria), while GSII genes only occur in eukaryotes and a few soil-dwelling bacteria. GSIII genes have been found in only a few bacterial species. Recently, it has been suggested that several lateral gene transfers of archaeal GSI genes to bacteria may have occurred. In order to study the evolution of GS, we cloned and sequenced GSI genes from two divergent archaeal species: the extreme thermophile Pyrococcus furiosus and the extreme halophile Haloferax volcanii. Our phylogenetic analysis, which included most available GS sequences, revealed two significant prokaryotic GSI subdivisions: GSI-a and GSI-. GSIa-genes are found in the thermophilic bacterium, Thermotoga maritima, the low G+C Gram-positive bacteria, and the Euryarchaeota (includes methanogens, halophiles, and some thermophiles). GSI--type genes occur in all other bacteria. GSI-- and GSI--type genes also differ with respect to a specific 25-amino-acid insertion and adenylylation control of GS enzyme activity, both absent in the former but present in the latter. Cyanobacterial genes lack adenylylation regulation of GS and may have secondarily lost it. The GSI gene of Sulfolobus solfataricus, a member of the Crenarchaeota (extreme thermophiles), is exceptional and could not be definitely placed in either subdivision. The S. solfataricus GSI gene has a shorter GSI--type insertion, but like GSI-a-type genes, lacks conserved sequences about the adenylylation site. We suspect that the similarity of GSI- genes from Euryarchaeota and several bacterial species does not reflect a common phylogeny but rather lateral transmission between archaea and bacteria.Correspondence to: J.R. Brown 1073     

Molecular biology and systematics of an extinct Lemur:Pachylemur insignis

The systematic position of the extinctPachylemur insignis has been controversial: some authors consideredPachylemur as a lemur, whereas others viewed it closer toVarecia. Its classification in the genusLemur orVarecia thus remained an open question. DNA extraction from subfossil bones, using a non-destructive method, allowed us to obtain enough material to make a Southern blot. The hybridization ofPachylemur withEulemur fulvus, Lemur catta, andVarecia variegata highly repeated DNA probes showed that only theVarecia probe gave a positive signal on hybridization on thePachylemur blot. These results indicate thatPachylemur must be considered closer to the genusVarecia than toEulemur andLemur.     

Predicting mean and variance of all possible lines and hybrids from designs with partially inbred progenies

Two-factor mating designs at consecutive S_n and S_(n+1) levels (S₀ and S₁ S₁ and S₂, or F₂ and F₃) allow estimation of all components of the variation among homozygous lines and F₁ hybrids that can be derived from a given population. They also allow for the prediction of the mean of these lines and single-cross hybrids. Some tests for the presence of epistasis are possible at the levels of means and of variances. Such mating designs can be very useful for predicting the value of the best possible lines or the best possible F₁ hybrids when it is difficult to produce, at an experimental level for exploratory purposes, either lines or hybrids.     

Induced diploid gynogenesis and polyploidy in the ornamental (koi) carp Cyprinus carpio L.

The results of a series of experiments conducted in our laboratory on the ornamental common carp (koi), aimed at optimizing heat-shock chromosome-set manipulation procedures, are described. The timing of heat-shock initiation was expressed in the relative unit of embryological age (₀) in order to standardize this parameter, the absolute time for heat-shock initiation being calculated from duration of one ₀ at two different pre-treatment water temperatures. Heat shocks were applied within the periods of 0.05–0.60 ₀ and 1.20–2.20 ₀ which, respectively, cover the successive phases of the 2nd meiotic division and the 1st cleavage. The highest production of diploid gynogenetic offspring was observed when heat shocks were initiated at 0.15–0.25 ₀ and at 1.5 ₀, after insemination, corresponding to anaphase of meiosis-II, and metaphase of the 1st cleavage, respectively. Similar results were obtained irrespective of the different pre-treatment water temperatures, thus confirming the possibility of standardizing heat-shock timing by ₀.     

Postpartum anestrus in French beef cattle: an epidemiological study

Postpartum anestrus of lactating beef cows was studied by means of an epidemiological study carried out on 878 lactating beef cows in 60 French herds. The cows calved between October 1992 and March 1993 and were housed 2 mo after calving, when the anestrus status was determined by progesterone radioimmunoassays. Data analysis was performed using a multiple logistic model in order to adjust for confounding and interaction. Fifty-one percent of the primiparous and 23% of the multiparous cows were found to be in anestrus. Factors significantly related to anestrus were parity (primiparous); breed (Charolais); housing type (tie housing); suckling (compared to weaning at birth); and, among those that were under the control of the farmer, calving conditions (manual exploration of the birth canal); body condition score at calving (3 or less, on a 5-point scale); and loss in body condition score after calving (1 point or more within 2 mo). Previous reproductive performance for multiparous cows such as a long calving interval and induced estrus in the previous year also appeared to be related to anestrus.     

Effect of shock-loading of heavy metals on total organic carbon and phosphate removal in an anaerobic-aerobic activated sludge process

The effect of shock-loading of zinc, copper and cadmium ions on the removal of total organic carbon (TOC) and phosphate in an anaerobic-aerobic activated sludge process was investigated. TOC removal was not sensitive to shock-loading of Zn²⁺ and Cd²⁺ ions, and complete removal was achieved even at 20 mg Zn²⁺/l and 20 mg Cd²⁺/l. However, with over 1 mg Cu²⁺/1 TOC removal efficiency decreased. PO _inf4 ^sup3- removal, in contrast, was extremely sensitive to these metal ions, with the threshold being 1 mg Zn²⁺/l and 1 mg Cd²⁺/l. Higher concentrations adversely affected PO _inf4 ^sup3- removal. Copper again proved detrimental; no PO _inf4 ^sup3- removal was achieved even at 1 mg Cu/l. These results highlight the sensitivity of the removal efficiencies of TOC and PO _inf4 ^sup3- to shock loadings of these heavy metals.Y.P. Ting is with the Department of Chemical Engineering, National University of Singapore, Kent Ridge, 0511, Singapore; H. Imai and S. Kinoshita are with the Department of Chemical Process Engineering, Hokkaido University, Sapporo 060, Japan.