Evolution of local recruitment and its consequences for marine populations

Advantages of dispersal on the scales that are possible in a long pelagic larval period are not apparent, even for benthic species. An alternative hypothesis is that wide dispersal may be an incidental byproduct of an ontogenetic migration from and then back to the parental habitat. Under this hypothesis, the water column is a better habitat than the bottom for early development. Because the parental area is often an especially favorable habitat for juveniles and adults, selection may even favor larval retention or larval return rather than dispersal. Where larval capabilities and currents permit, a high percentage of recruits may then be produced from local adults. Expected consequences of a high proportion of local recruitment are stronger links between stock and recruitment, greater vulnerability to recruitment overfishing and local modifications of habitat, greater local benefits from fishery reserves, and possibly more localized adaptation within populations. Export of some larvae is consistent with a high proportion of retained or returning larvae, could stabilize populations linked by larval exchange, and provide connectivity between marine reserves. Even a small amount of larval export could account for the greater gene flow, large ranges, and long evolutionary durations seen in species with long pelagic larval stages.

Epidemiological modelling (including economic modelling) and its role in preventive drug therapy

In contrast to curative therapies, preventive therapies are administered to largely healthy individuals over long periods. The risk-benefit and cost-benefit ratios are more likely to be unfavourable, making treatment decisions difficult. Drug trials provide insufficient information for treatment decisions, as they are conducted on highly selected populations over short durations, estimate only relative benefits of treatment and offer little information on risks and costs. Epidemiological modelling is a method of combining evidence from observational epidemiology and clinical trials to assist in clinical and health policy decision-making. It can estimate absolute benefits, risks and costs of long-term preventive strategies, and thus allow their precise targeting to individuals for whom they are safest and most cost-effective. Epidemiological modelling also allows explicit information about risks and benefits of therapy to be presented to patients, facilitating informed decision-making.

Interaction of RTD-1, a cyclic antimicrobial defensin from Rhesus macaque leukocytes, and its open chain analogue with membrane mimics

In contrast to other mammalian defensins, rhesus theta defensin-1 (RTD-1) is composed of just 18 amino acids with the backbone cyclized through peptide bonds. Antibacterial activities of both the native cyclic peptide and a linear form were examined, showing that the cyclic form was 3-fold more active than the open chain analogue, oRTD-1, although both peptides adopt very similar structures in water. It was suggested that the additional charges at the termini of oRTD-1 are the cause for its lower antimicrobial activity. Therefore, we studied the interaction of both peptides with membrane mimics composed of zwitterionic (PC) and negatively charged (PG) phospholipids, major lipid components of erythrocyte and bacterial cell membranes, respectively. Microcalorimetry showed that RTD-1 and oRTD-1 did not affect the phase behavior of PC liposomes, while in PG liposomes both peptides induced new phase transitions above the chain melting transition of the lipid. The shape and fraction differed between both peptides, depending also on their concentration, which will be discussed in terms of their antimicrobial activity.

Late Quaternary Milankovitch-scale climatic change and variability and its impact on monsoonal Australasia

Four pollen and charcoal records derived from marine cores around the northern perimeter of Australia are examined to provide a regional picture of patterns, causes and impacts of climate change over the last 100-300 ka. The availability of radiocarbon dates and oxygen isotope records for the cores provides primary chronological control. Spectral analysis of components of these records demonstrates an overall importance of Milankovitch frequencies with clear glacial-interglacial cyclicity dominated by variation in precipitation. In addition, a number of pollen taxa, as well as charcoal particles, exhibit a 30 ka frequency that is considered, from its relationship with biomass burning and with results of past modelling, to reflect changes in the intensity of El Nino-Southern Oscillation (ENSO) variability. Pollen components of all records show a decline, frequently stepwise, in more fire-sensitive vegetation and its replacement with more fire-tolerant vegetation. There is some evidence that this trend is linked to an onset or general increase in ENSO activity and perhaps also to variation in monsoon activity dating from about 300 ka BP that was caused by changes to oceanic circulation within the Indonesian region. The trend may have accelerated within the last 45 ka due to burning by indigenous people. (C) 2003 Elsevier B.V. All rights reserved.

Polarization vision and its role in biological signaling

Visual pigments, the molecules in photoreceptors that initiate the process of vision, are inherently dichroic, differentially absorbing light according to its axis of polarization. Many animals have taken advantage of this property to build receptor systems capable of analyzing the polarization of incoming light, as polarized light is abundant in natural scenes (commonly being produced by scattering or reflection). Such polarization sensitivity has long been associated with behavioral tasks like orientation or navigation. However, only recently have we become aware that it can be incorporated into a high-level visual perception akin to color vision, permitting segmentation of a viewed scene into regions that differ in their polarization. By analogy to color vision, we call this capacity polarization vision. It is apparently used for tasks like those that color vision specializes in: contrast enhancement, camouflage breaking, object recognition, and signal detection and discrimination. While color is very useful in terrestrial or shallow-water environments, it is an unreliable cue deeper in water due to the spectral modification of light as it travels through water of various depths or of varying optical quality. Here, polarization vision has special utility and consequently has evolved in numerous marine species, as well as at least one terrestrial animal. In this review, we consider recent findings concerning polarization vision and its significance in biological signaling.

Purification of the keratan sulfate proteoglycan expressed in prostatic secretory cells and its identification as lumican

BACKGROUND. Secretory epithelial cells of human prostate contain a keratan sulfate proteoglycan (KSPG) associated with the prostatic secretory granules (PSGs). The proteoglycan has not been identified, but like the PSGs, it is lost in the early stages of malignant transformation. METHODS. Anion exchange and affinity chromatography were used to purify KSPG from human prostate tissue. Enzymatic deglycosylation was used to remove keratan sulfate (KS). The core protein was isolated using 2D gel electrophoresis, digested in-gel with trypsin, and identified by peptide mass fingerprinting (PMF). RESULTS. The purified proteoglycan was detected as a broad smear on Western blots with an apparent molecular weight of 65-95 kDa. The KS moiety was susceptible to digestion with keratanase 11 and peptide N-glycosidase F defining it as highly sulfated and N-linked to the core protein. The core protein was identified, following deglycosylation and PMF, as lumican and subsequently confirmed by Western blotting using an anti-lumican antibody. CONCLUSIONS. The KSPG associated with PSGs in normal prostate epithelium is lumican. While the role of lumican in extracellular matrix is well established, its function in the prostate secretory process is not known. It's potential to facilitate packaging of polyamines in PSGs, to act as a tumor suppressor and to mark the early stages of malignant transformation warrant further investigation. (C) 2003 Wiley-Liss, Inc.

Floral developmental morphology of three Indigofera species (Leguminosae) and its systematic significance within Papilionoideae

Inflorescence and floral development of three species of Indigofera (Leguminosae-Papilionoideae), I. lespedezioides, I. spicata, and I. suffruticosa, were investigated and compared with that of other papilionoid groups, especially with members of the recently circumscribed Millettioid clade, which was merged as sister to Indigofereae in a recent cladistic analysis. Although Indigofera is a genus of special interest, because of its great richness in species and its economic importance, few studies have been made of floral development in the genus or in Indigofereae as a whole. Flower buds and inflorescences were analysed at several stages of development in the three species. Our results confirmed that Indigofera species bear a usual inflorescence type among legumes, the raceme, which comprises flowers initiated in acropetal succession, each with a subtending bract and no bracteoles initiated. The inception of the floral organs is as follows: sepals (5), petals (5), carpel (1), outer stamens (5), and, finally, inner stamens (5). Organ initiation in the sepal, petal, and both stamen whorls is unidirectional, from the abaxial side; the carpel cleft is adaxial. The vexillum is larger than other petals at maturity, covering the keels, which are fused edge-to-edge. Nine filaments are fused to form an adaxially open sheath, and the adaxial stamen of the inner whorl remains free (diadelphous androecium) in the mid-stage of development. Most of the infra-generic differences occurred in the later stages of development. Data on floral development in Indigofera obtained here were also compared with those from other members of Papilionoideae. This comparison showed that the early expression of zygomorphy is shared with other members of the Millettioid clade but is rarely found in other papilionoids, corresponding to a hypothetically morphological synapomorphy in the pair Indigoferae plus millettioids.

The sound field generated by tethered stingless bees (Melipona scutellaris): inferences on its potential as a recruitment mechanism inside the hive

In stingless bees, recruitment of hive bees to food sources involves thoracic vibrations by foragers during trophallaxis. The temporal pattern of these vibrations correlates with the sugar concentration of the collected food. One possible pathway for transfering such information to nestmates is through airborne sound. In the present study, we investigated the transformation of thoracic vibrations into air particle velocity, sound pressure, and jet airflows in the stingless bee Melipona scutellaris. Whereas particle velocity and sound pressure were found all around and above vibrating individuals, there was no evidence for a jet airflow as with honey bees. The largest particle velocities were measured 5 mm above the wings (16.0 +/- 4.8 mm s(-1)). Around a vibrating individual, we found maximum particle velocities of 8.6 +/- 3.0 mm s(-1) (horizontal particle velocity) in front of the bee`s head and of 6.0 +/- 2.1 mm s(-1) (vertical particle velocity) behind its wings. Wing oscillations, which are mainly responsible for air particle movements in honey bees, significantly contributed to vertically oriented particle oscillations only close to the abdomen in M. scutellaris(distances <= 5 mm). Almost 80% of the hive bees attending trophallactic food transfers stayed within a range of 5 mm from the vibrating foragers. It remains to be shown, however, whether air particle velocity alone is strong enough to be detected by Johnston`s organ of the bee antenna. Taking the physiological properties of the honey bee`s Johnston`s organ as the reference, M. scutellaris hive bees are able to detect the forager vibrations through particle movements at distances of up to 2 cm.

Heterologous expression of an Aspergillus niveus xylanase GH11 in Aspergillus nidulans and its characterization and application

A xylanase was cloned from Aspergillus niveus and successfully expressed in Aspergillus nidulans (XAN). The full-length gene consisted of 890 bp and encoded 275 mature amino acids with a calculated mass of 31.3 kDa. The deduced amino acid sequence was highly homologous with the xylanase belonging to family 11 of the glycoside hydrolases. The recombinant protein was purified to electrophoretic homogeneity by anion-exchange chromatography and gel filtration. The optima of pH and temperature for the recombinant enzyme were 5.0 and 65 degrees C, respectively. The thermal stability of the recombinant xylanase was extremely improved by covalent immobilization on glyoxyl agarose with 91.4% of residual activity after 180 min at 60 degrees C, on the other hand, the free xylanase showed a half-life of 9.9 min at the same temperature. Affinity chromatography on Concanavalin A- and Jacalin-agarose columns followed by SDS-PAGE analyses showed that the XAN has O- and N-glycans. XAN promotes hydrolysis of xylan resulting in xylobiose, xylotriose and xylotetraose. Intermediate degradation of xylan resulting in xylo-oligomers is appealing for functional foods as the beneficial effect of oligosaccharides on gastrointestinal micro flora includes preventing proliferation of pathogenic intestinal bacteria and facilitates digestion and absorption of nutrients. (C) 2011 Elsevier Ltd. All rights reserved.

The identity of Paratrizygia conformis Tonnoir (Diptera, Mycetophilidae), with comments on its systematic position

Paratrizygia conformis, the type-species of the genus Paratrizygia, from Tasmania, is redescribed from the holotype. The wing venation and male terminalia are illustrated in detail. The question of the monophyly of the genus-which has four additional species in Chile and southern Argentina, and four species in the Atlantic Forest, in Brazil-is addressed. Comments are made on the relationships of the genus in the Azana-group of Sciophilinae. The hypothesis of monophyly of Paratrizygia is retained, as indicated by the presence of modified, elongated spines on a distal fold of tergite 9.

Surgical management of lung cancer in Western Australia in 1996 and its outcomes

Background: All cases of lung cancer diagnosed in Western Australia in 1996 in which surgery was the primary treatment, were reviewed. Reported herein are the characteristics of the patients, the treatment outcomes and a comparison of the management undertaken with that recommended by international guidelines. Methods: All patients with a new diagnosis of lung cancer in Western Australia in the calendar year of 1996 were identified using two different population-based registration systems: the Western Australian (WA) Cancer Registry and the WA Hospital Morbidity Data System. A structured questionnaire on the diagnosis and management was completed for each case. Date of death was determined through the WA Cancer Registry. Results: Six hundred and sixty-eight patients with lung cancer were identified; 132 (20%) were treated with surgery. Lobectomy was the most frequently performed procedure (71%), followed by pneumonectomy (19%). Major complications affected 23% of patients. Postoperative mortality was 6% (3% lobectomy, 12% pneumonectomy). At 5 years the absolute survival was as follows for stage I, II, IIIA, IIIB, respectively: 51%, 45%, 12%, 5%. Conclusions: Investigations and choice of surgery in WA in 1996 reflect current international guidelines. The survival of patients with resectable lung cancer remains unsatisfactory.