SHELF-LIFE ESTIMATION OF APPLE-BABY FOOD

The aim of the present work was to study the evolution of the color of an apple‐baby food and to estimate its sensory shelf life. Samples of apple‐baby food stored at 25C were analyzed using trained assessors and a consumer panel. A zero‐order reaction kinetics was found for the evolution of sensory color with storage time. Color was highly correlated with consumers' rejection percentage and overall acceptability, which indicates that consumers consider this attribute when deciding to accept or reject this product and in assigning their acceptability scores. Using this correlation, the sensory cutoff point for color, corresponding to a 25% consumer rejection, was calculated. Sensory shelf life was estimated using consumer data. Sensory shelf life estimated by survival analysis was in agreement with that calculated considering an acceptability limit of 6.0 in a 9‐point hedonic scale.     

A new species of the "mateusi" group: Iberobathynella ortizi sp.n. (Crustacea, Syncarida, Parabathynellidae)

A new species of the genus Iberobathynella Schminke, 1973. is described. The speclmens were found in Cova do Rei Cintolo. Lugo, Spain. The species is included in the "mateusi" group. according to Schminke's (1973) cladistic analysis.     

Chloroplast Protein Synthesis During Barley Leaf Growth and Senescence: Effect of Leaf Excision

Chloroplast protein synthesis was measured during the expansion,maturity and senescence of the oldest leaf of barley, Hordeumvulgare L., var. Hassan. A maximum rate of protein synthesisoccurred near the end of the expansion stage 9 d after sowing.Protein synthesis increased again at the beginning of senescenceand reached a new maximum at day 14 after sowing. Detachmentand incubation of leaves in the dark stimulated chioroplastprotein synthesis by fully expanded or by senescent leaves butnot by expanding leaves. If the detached leaves were kept inthe light, chloroplast protein synthesis was stimulated in fullyexpanded but not in senescent leaves. Short treatments (18 h)of leaf segments with growth substances in either light or indarkness, significantly changed the rate of protein synthesisshown by chloroplasts. The relationship between chloroplastprotein synthesis and leaf senescence is discussed. Key words: Hormones, light, maturity     

Changes in Cell Wall Polysaccharides During the Growth of Phaseolus vulgaris Leaves

The changes in pectic and hemicellulosic polysaccharides, and-cellulose during the expansion growth of the primary leavesof Phaseolus vulgaris L. var. Pinta have been studied. -Celluloseincreased continuously with age, while pectic and water-solublehemicellulose extracted with 4% KOH fractions slightly decreased.The water-soluble hemicelluloses extracted with 24% KOH showedthe most conspicuous changes, increasing until the 8th day,when the absolute growth rate was maximal, and thereafter decreasing.Furthermore, the study of the molecular mass distribution ofpectin, and water-soluble polysaccharides extracted with 4%and 24% KOH, showed an increase in the degree of polymerizationof polyuronic acid and xylan, and an important depolymerizationof galactan and xyloglucan. Accordingly, the mechanism of cellwall loosening in the leaf cell walls is similar to that describedfor plant axes. Key words: Cell wall, growth, leaf     

Between‐year variations in Little Bustard Tetrax tetrax population densities are influenced by agricultural intensification and rainfall

The Little Bustard is suffering a widespread population decline mainly due to agricultural intensification. This study evaluates the effects of intensification level, habitat availability and rainfall on the population dynamics of this species. The population density of males was monitored for 7 years (2002–2008) at 184 points located within three sites with contrasting levels of agricultural intensification in southern Portugal. Densities decreased along the intensification gradient from 8.2 to 2.3 males / km². Overall, there was an approximately 50% population decline during the period 2002–2008, driven by a decline observed in one of the less intensive sites, whereas in the other two sites densities remained fairly constant. Yearly variations in male densities were influenced by intensification level, amount of grassland habitat and rainfall patterns. Thus, agricultural intensification is having a negative effect on population densities of this threatened species, particularly through the loss of grasslands (fallow fields and pastures) suitable for displaying males. The results also suggest a positive impact of rainfall on male densities, although this is more likely in grasslands within less intensive agricultural regions of poorer soil quality, where higher breeding male densities occur. Grassland habitat quality, driven by both climate and human management, probably plays a major role in the population dynamics of this threatened steppe bird in its strongholds.     

Ant versus bird exclusion effects on the arthropod assemblage of an organic citrus grove

1. Predation‐exclusion experiments have highlighted that top‐down control is pervasive in terrestrial communities, but most of these experiments are simplistic in that they only excluded a single group of predators and the effect of removal was evaluated on a few species from the community. The main goal of our study was to experimentally establish the relative effects of ants and birds on the same arthropod assemblage of canopy trees. 2. We conducted 1‐year long manipulative experiments in an organic citrus grove intended to quantify the independent effects of bird and ant predators on the abundance of arthropods. Birds were excluded with plastic nets whereas ants were excluded with sticky barriers on the trunks. The sticky barrier also excluded other ground dwelling insects, like the European earwig Forficula auricularia L. 3. Both the exclusion of ants and birds affected the arthropod community of the citrus canopies, but the exclusion of ants was far more important than the exclusion of birds. Indeed, almost all groups of arthropods had higher abundance in ant‐excluded than in control trees, whereas only dermapterans were more abundant in bird‐excluded than in control trees. A more detailed analysis conducted on spiders also showed that the effect of ant exclusion was limited to a few families rather than being widespread over the entire diverse spectrum of spiders. 4. Our results suggest that the relative importance of vertebrate and invertebrate predators in regulating arthropod populations largely depends on the nature of the predator–prey system.     

REACTION OF FIN WHALES BALAENOPTERA PHYSALUS TO AN EARTHQUAKE

ABSTRACT

Whales living within seismically active regions are subject to intense disturbances from strong sounds produced by earthquakes that can kill or injure individuals. Nishimura & Clark (1993) relate the possible effects of underwater earthquake noise levels in marine mammals, adducing that T-phase source signal level (10- to 30- Hz range) can exceed 200 dB re: 1 μPa at 1 m, for a magnitude 4–5 earthquake, sounds audible to fin whales which produce low frequency sounds of 16–20/25–44 Hz over 0.5–1s, typically of 183 dB re: 1 μPa at 1 m. Here we present the response of a fin whale to a 5.5 Richter scale earthquake that took place on 22 February 2005, in the Gulf of California. The whale covered 13 km in 26 min (mean speed = 30.2 km/h). We deduce that the sound heard by this whale might have triggered the costly energy expenditure of high speed swimming as a seismic-escape response. These observations support the hypothesis of Richardson et al. (1995) that cetaceans may flee from loud sounds before they are injured, when exposed to noise in excess of 140 dB re: 1 μPa 1 m.     

CHANGES IN CLICK SOURCE LEVELS WITH DISTANCE TO TARGETS: STUDIES OF FREE-RANGING WHITE-BEAKED DOLPHINS LAGENORHYNCHUS ALBIROSTRIS AND CAPTIVE HARBOUR PORPOISES PHOCOENA PHOCOENA

ABSTRACT

Probably all odontocetes use echolocation for spatial orientation and detection of prey. We used a four hydrophone “Y” array to record the high frequency clicks from free-ranging White-beaked Dolphins Lagenorhynchus albirostris and captive Harbour Porpoises Phocoena phocoena. From the recordings we calculated distances to the animals and source levels of the clicks. The recordings from White-beaked Dolphins were made in Iceland and those from Harbour Porpoises at Fjord & Baelt, Kerteminde, Denmark during prey capture. We used stringent criteria to determine which clicks could be defined as being on the acoustic axis. Two dolphin and nine porpoise click series could be used to track individual animals, which presumably focused on the array hydrophones or a fish right in front of the array. The apparent source levels of clicks in the individual tracks increased with range. One individual White-beaked Dolphin and three Harbour Porpoises regulate their output signal level to nearly compensate for one-way transmission loss while approaching a target. The other dolphin regulated the output differently. For most of the recordings the sound level at the target remains nearly constant and the echo level at the animal increases as it closes on the target.