Rapid estimation of spoilage bacterial load in aerobically stored meat by a quantitative polymerase chain reaction

We report a quantitative PCR which utilizes primers from a conserved 23S rDNA sequence identified in nine different spoilage bacteria commonly present in meat. The PCR detected the spoilage bacteria by amplifying a specific 207 bp sequence from their chromosomal DNA. Quantification of PCR product by electrochemiluminescence revealed that the concentration of the amplified product was dependent on cycle number and the initial number of bacteria present in the sample. Statistical analysis of the results indicated a correlation coefficient of 0.94 (P < 0.001) between aerobic plate count and QPCR luminosity units.     

Interaction of elongation factor 1alpha from Zea mays (ZmEF-1alpha) with F-actin and interplay with the maize actin severing protein, ZmADF3.

EF-1alpha is an abundant eukaryotic protein whose principle function appears to be to bind aminoacyl-tRNA to the ribosome. However, it is also known that EF-1alpha from other sources binds both microtubules and microfilaments. We report the expression of Zea mays EF-1alpha (ZmEF-1alpha) in bacteria and that this protein has similar actin-binding properties as other EF-1alpha members. ZmEF-1alpha bundles actin filaments at low pH (6.5) and inhibits the addition of monomer at both filament ends, possibly as a consequence. ZmEF-1alpha binds actin filaments at all pH values tested (pH 6.0-8.0), indicating that one actin binding site is not pH sensitive. One of the actin-binding sites was determined to reside within domain I (1-223) of ZmEF-1alpha, but this domain did not affect the kinetics of polymerisation. We show that the bundling activity of ZmEF-1alpha is modulated by ZmADF3 a (a Zea mays ADF/cofilin), an actin filament severing protein, in vitro. Bundling of actin filaments caused by ZmEF-1alpha was enhanced in the presence of ZmADF3. The pH-dependent activities of both proteins in vitro suggests that they may work together to respond to temporal and spatial intracellular pH changes to regulate the pattern of the growth of plant cells.     

Andrographis chendurunii, a new species of Acanthaceae from India

A new species of Andrographis, A. chendurunii is described and illustrated from Kerala, India.     

Anomalous salting-out behaviour of cyanogen bromide fragments of bovine serum albumin

The solubilities of bovine serum albumin and its two cyanogen bromide fragments comprising domain I and II+III of the protein in ammonium sulphate solution were studied at different pH and temperature and the salting-out parameters K_s and β were determined for the three proteins. The values of K_s and β obtained for the intact albumin at different pH were atypical of other globular proteins and were explained in terms of N-F transition and pH induced unfolding of the protein. The salting-out behaviour of the two fragments was, however, found to be significantly different from that of their parent molecule. In contrast to bovine serum albumin, the aqueous solubilities of the two fragments were highly dependent on temperature. Similarly, pH dependence of β for the two fragments was also different since it acquired a minimum value at about pH 4.0 as against its monotonic decrease with pH observed in intact albumin below pH 5.0. Anomalous salting-out behaviour of the two cyanogen bromide fragments has been attributed to the possible conformational changes that might occur during the course of their preparation under relatively harsher chemical conditions.     

Diosbulbin d and 8-epidiosbulbin e acetate,norclerodane diterpenoids from dioscorea bulbifera tubers

From tubers of Dioscorea buibifera L. var sativa a new 18-norclerodane diterpenoid, 8-epidiosbulbin E acetate, has been isolated, besides the previously known norditerpenoid, diosbulbin D, and its structure established by spectroscopic means.     

Combination vs. disproportionation in dialkyl biradicals. Selectivity reversal in a crystalline solid.

While 1,6-biradicals produced by photodecarbonylation of dimethyl 11-oxodibenzo[c,h]bicyclo[4.4.1]undeca-3,8-diene-1,6-dicarboxylate (1) react exclusively by disproportionation in benzene solution, reactions in crystals lead to radical-radical combination reactions in almost quantitative yield.     

Measurement of the CO2 apneic threshold in newborn infants: possible relevance for periodic breathing and apnea.

We measured the PCO2 apneic threshold in preterm and term infants. We hypothesized that, compared with adult subjects, the PCO2 apneic threshold in neonates is very close to the eupneic PCO2, likely facilitating the appearance of periodic breathing and apnea. In contrast with adults, who need to be artificially hyperventilated to switch from regular to periodic breathing, neonates do this spontaneously. We therefore measured the apneic threshold as the average alveolar PCO2 (PaCO2) of the last three breaths of regular breathing preceding the first apnea of an epoch of periodic breathing. We also measured the PaCO2 of the first three breaths of regular breathing after the last apnea of the same periodic breathing epoch. In preterm infants, eupneic PaCO2 was 38.6 +/- 1.4 Torr, the preperiodic PaCO2 apneic threshold was 37.3 +/- 1.4 Torr, and the postperiodic PaCO2 was 37.2 +/- 1.4 Torr. In term infants, the eupneic PaCO2 was 39.7 +/- 1.1 Torr, the preperiodic PaCO2 apneic threshold was 38.7 +/- 1.0 Torr, and the postperiodic value was 37.9 +/- 1.2 Torr. This means that the PaCO2 apneic thresholds were 1.3 +/- 0.1 and 1.0 +/- 0.2 Torr below eupneic PaCO2 in preterm and term infants, respectively. The transition from eupneic PaCO2 to PaCO2 apneic threshold preceding periodic breathing was accompanied by a minor and nonsignificant increase in ventilation, primarily related to a slight increase in frequency. The findings suggest that neonates breathe very close to their PCO2 apneic threshold, the overall average eupneic PCO2 being only 1.15 +/- 0.2 Torr (0.95-1.79, 95% confidence interval) above the apneic threshold. This value is much lower than that reported for adult subjects (3.5 +/- 0.4 Torr). We speculate that this closeness of eupneic and apneic PCO2 thresholds confers great vulnerability to the respiratory control system in neonates, because minor oscillations in breathing may bring eupneic PCO2 below threshold, causing apnea.     

Evaluation of Napier grass (Pennisetum purpureum) varieties for use as trap plants for the management of African stemborer (Busseola fusca) in a push–pull strategy

We evaluated eight Napier grass [Pennisetum purpureum Schumach (Poaceae)] varieties, used in various parts of eastern Africa as fodder, for their potential role as trap plants in the management of the African stemborer, Busseola fusca Füller (Lepidoptera: Noctuidae) through a push–pull strategy. Oviposition preference, larval orientation, settling, arrest and dispersal, feeding, mortality and survival, and development were determined for each of these varieties under laboratory and screen house conditions. Two‐choice tests showed that only two of the varieties tested (cv. Bana and cv. Uganda Hairless) were preferentially chosen by gravid female moths for oviposition over a susceptible maize variety, cv. Western Hybrid 502. Larval preference was, however, highly variable. Larval feeding by first instars on the maize leaves was more intense and significantly more than on leaves of all the Napier grass varieties evaluated. Food consumed and amounts assimilated by the third instars over a 24‐h period were not different among larvae fed on stems of maize and those fed on stems of the various Napier grass varieties. Larval survival was significantly lower on all the Napier grass varieties (below 3%) than on maize (about 44%). Similarly, larval development was about 2–3 weeks longer on majority of the Napier grass varieties. It was concluded that cv. Bana had potential for use as a trap plant in the management of B. fusca because it was more preferred by the moths for oviposition, equally preferred as maize by the larvae for orientation, settling, and arrest, and allowed minimal survival of the larvae. It can thus be used with such ‘push’ plants as Desmodium spp. (Fabaceae) in a ‘push–pull’ strategy, but the effectiveness of such a strategy would strictly depend on proper establishment and management of these companion plants.