Fluctuations of grass pollen content in the atmosphere of East Perugia and meteorological correlations (year 1989)

Summary Gramineae pollination from a pollen monitoring station located in the eastern suburb of Perugia and meteorological correlations are reported. The data refers to the year 1989. Grass pollen peak pollination was from May to July; in this period the influence of relative humidity and of temperature on pollen concentration was very high. Phenological observations, to identify the time of maximum stamen extension in the most common genera in the area, are also reported. During the period of investigation the counts of pollen grains over four-hour periods showed a regular diurnal rhythm with peaks of concentration in the four-hour period 16.00–20.00. Aerosporological data and meteorological data related to four-hour periods were correlated following different criteria.     

Climate Driven Life Histories: The Case of the Mediterranean Storm Petrel

Seabirds are affected by changes in the marine ecosystem. The influence of climatic factors on marine food webs can be reflected in long-term seabird population changes. We modelled the survival and recruitment of the Mediterranean storm petrel (Hydrobates pelagicus melitensis) using a 21-year mark-recapture dataset involving almost 5000 birds. We demonstrated a strong influence of prebreeding climatic conditions on recruitment age and of rainfall and breeding period conditions on juvenile survival. The results suggest that the juvenile survival rate of the Mediterranean subspecies may not be negatively affected by the predicted features of climate change, i.e., warmer summers and lower rainfall. Based on considerations of winter conditions in different parts of the Mediterranean, we were able to draw inferences about the wintering areas of the species for the first time.     

Influence of Organic-Phosphates on 3-Phosphoglycerate Dependent O2 Evolution in C3 and C4 Mesophyll Chloroplasts

In C₄ plants phosphoenolpyruvate (PEP) of the C₄ cycle may betransported on a chloroplast transporter which also transports3-phosphoglycerate (3-PGA) and triosephosphates. In C₃ plantsPEP is not considered to be effectively transported on the chloroplastphosphate translocator. The influences of certain organic phosphates,having a similar structure to either PEP or triose-phosphates,on 3-PGA dependent O₂ evolution by C₄ (Digitaria sanquinalisL. Scop.) and C₃ (Hordeum vulgare L.) mesophyll chloroplastswere investigated. In the C₄ mesophyll chloroplasts phosphoglycolatewas a competitive inhibitor (K_i = 2.1 mM) of 3-PGA dependentO₂ evolution, and was as effective as previously reported forPEP. 2-Phosphoglycerate was also a competitive inhibitor (K_t= 8.6 mM) of O₂ evolution in the C₄ mesophyll chloroplasts with3-PGA as substrate, while phospholactate was a weak inhibitorand glyphosate had no effect. Neither PEP, phosphoglycolatenor 2-phosphoglycerate were effective inhibitors of 3- PGA dependentO₂ evolution in the C₃ chloroplasts. Phosphohydroxypyruvatewas a competitive inhibitor of 3-PGA dependent O₂2 evolutionin both chloroplast types. The selectivity in inhibition ofO₂ evolution with 3-PGA as substrate suggests that the C₄ mesophyllchloroplasts can recognize certain organic phosphates with thephosphate in the C-2 or C-3 position but that the C₄ mesophyllchloroplasts can only effectively recognize certain organicphosphates with the phosphate in the C-3 position. The resultsalso support the view that 3-PGA and PEP are transported onthe same phosphate translocator in C₄ mesophyll chloroplasts. ¹ Current address: Department of Horticulture, 2001 Fyffe Court,The Ohio State University, Columbus, Ohio 43210-1096. (Received March 24, 1987; Accepted April 16, 1987)     

Binding of [3H]estradiol- and [3H]H1285-receptor complexes to rabbit uterine chromatin

In the present study we investigated the binding characteristics of estrogen and antiestrogen-receptor complexes to rabbit uterine chromatin. Activated or nonactivated estrogen receptors were partially purified by DEAE-cellulose chromatography using low (1 mM) or high (10 mM) concentrations of sodium molybdate. Activated [³H]estradiol-receptor complexes showed enhanced binding to chromatin acceptor sites unmasked by 1 M, 4 M and 6 M guanidine hydrochloride. We also examined the chromatin-binding characteristics of the estrogen receptors when bound by the high-affinity triphenylethylene antiestrogen, H1285. The acceptor site activity for the [³H]H1285-receptor complexes was markedly decreased at sites unmasked by 4 M and 6 M guanidine hydrochloride. Further, the nonactivated receptor complexes showed very low binding to deproteinized chromatin. The estrogen-receptor chromatin-acceptor sites were tissue specific and saturable. These chromatin acceptor sites differ in their affinity and capacity (number of binding sites per cell) for the estrogen- and antiestrogen-receptor complexes. Thus, we suggest that the differences in the physiological and physicochemical properties of estrogens and antiestrogens may be related to their differential interaction with uterine chromatin subfractions.     

Solubility characteristics of Micrococcus lysodeikticus membrane components in detergents and chaotropic salts analyzed by immunoelectrophoresis

In order to evaluate the effectiveness and selectivity of various reagents in the solubilization of bacterial membranes, membranes of Micrococcus lysodeikticus were treated with detergents and chaotropic agents. The composition of the extracts so obtained was analyzed by rocket and two-dimensional immunoelectrophoretic techniques. Recovery of succinate-, malate-, and reduced nicotinamide adenine dinucleotide- (NADH) dehydrogenases, ATPase, succinylated lipomannan and cytochromes in the extracts was measured. Treatment with a variety of non-denaturing detergents produced extracts that were generally qualitatively uniform although quantitative differences were observed. The degree of extraction of various components was correlated with the hydrophile-lipophile balance. Several chaotropic agents were also evaluated as reagents for membrane solubilization. These agents were less effective in extraction of bulk protein, but produced extracts enriched in some membrane components.