A set of microsatellite primers for the striped possum,Dactylopsila trivirgata (Petauridae: Marsupialia)

The New Guinean endemic dactylopsilines are members of the Petauridae possum family, represented in Australia only by the striped possum Dactylopsila trivirgata. The shy nature and low density of this species have hampered studies of its ecology to date, so we developed nine highly variable polymorphic microsatellite markers to enable molecular genetic analysis of population structure and mating system parameters. This will add substantially to our understanding of the behavioural ecology of this species. The low degree of cross‐amplification of the primers in other petaurid species lends weight to other evidence suggesting that this family underwent a relatively early radiation.     

The Structure of the Hypothalamohypophysial Portal Vascular System in Acipenser ruthenus L. (Chondrostei)

The vascularization of the pituitary region in Acipenser ruthenus L. (Chondrostei) is described. The adenohypophysis has no direct arterial supply but is fed exclusively by a pituitary portal system supplied through a pair of infundibular arteries. Distinct portal vessels connect the lateral part of the primary plexus of the neurohaemal area (the median eminence) with the secondary plexus of the pituitary gland. The primary plexus enters the pars distalis paramedially, apparently without the formation of distinct portal vessels. The neuro-intermediate lobe receives its blood supply exclusively from the primary plexus. The plexus intermedius gives off capillaries to the parenchyma of the intermediate lobe (an intermediate lobe sinus system). The saccus vasculosus receives (1) a “direct” supply, i.e. branches originating directly from the cerebral arteries and (2) an “indirect” supply, i.e. capillaries from the primary plexus. The pars distalis is drained into an unpaired ventral hypophysial vein, while a dorsal hypophysial vein, also unpaired, drains the plexus intermedius. These two veins join to form the unpaired hypophysial vein. The findings are discussed from comparative and functional viewpoints.     

Effect of truncated glucagon-like peptide 1 on cAMP in rat gastric glands and HGT-1 human gastric cancer cells

We tested the truncated 7-37 glucagon-like peptide 1 (TGLP-1), a naturally occurring porcine intestinal peptide, and other members of the glucagon family, including pancreatic glucagon (G-29), GLP-1 and GLP-2 for their ability to activate the cAMP generating system in rat gastric glands and HGT-1 human gastric cancer cells. In rat fundic glands, TGLP-1 was about 100 times more potent (EC50 = 2.8 X 10(-9) M) than GLP-1 of G-29, and 10 times more potent than G-29 in the HGT-1 cell line. Our results support the notion that TGLP-1 plays a direct role in the regulation of acid secretion in rat and human gastric mucosa.     

Considering Future Potential Regarding Structural Diversity in Selection of Forest Reserves

A rich structural diversity in forests promotes biodiversity. Forests are dynamic and therefore it is crucial to consider future structural potential when selecting reserves, to make robust conservation decisions. We analyzed forests in boreal Sweden based on 17,599 National Forest Inventory (NFI) plots with the main aim to understand how effectiveness of reserves depends on the time dimension in the selection process, specifically by considering future structural diversity. In the study both the economic value and future values of 15 structural variables were simulated during a 100 year period. To get a net present structural value (NPSV), a single value covering both current and future values, we used four discounting alternatives: (1) only considering present values, (2) giving equal importance to values in each of the 100 years within the planning horizon, (3) applying an annual discount rate considering the risk that values could be lost, and (4) only considering the values in year 100. The four alternatives were evaluated in a reserve selection model under budget-constrained and area-constrained selections. When selecting young forests higher structural richness could be reached at a quarter of the cost over almost twice the area in a budget-constrained selection compared to an area-constrained selection. Our results point to the importance of considering future structural diversity in the selection of forest reserves and not as is done currently to base the selection on existing values. Targeting future values increases structural diversity and implies a relatively lower cost. Further, our results show that a re-orientation from old to young forests would imply savings while offering a more extensive reserve network with high structural qualities in the future. However, caution must be raised against a drastic reorientation of the current old-forest strategy since remnants of ancient forests will need to be prioritized due to their role for disturbance-sensitive species.     

Low-pH-mediated elevations in cytosolic calcium are inhibited by aluminium: a potential mechanism for aluminium toxicity

Aluminium, the most abundant metal in the earth's crust, is highly toxic to most plant species. One of the prevailing dogmas is that aluminium exerts this effect by disrupting cellular calcium homeostasis. However, recent research gives strongly conflicting results: aluminium was shown to provoke either an increase or a decrease in cytosolic free calcium concentration ([Ca2+]c). To solve this question, we have adopted a novel approach: [Ca2+]c measurements in intact plant roots as opposed to isolated cells, and the correlative measurements of intracellular and external pH. The results obtained show that plant roots respond to low external pH by a sustained elevation in [Ca2+]c. In the presence of aluminium, this pH-mediated elevation in [Ca2+]c does not occur, therefore any potential calcium-mediated protection against low pH is likely to be irreversibly inhibited. The severity of the inhibitory effect of aluminium on [Ca2+]c depends on the concentration of external calcium, thus perhaps explaining why the effects of aluminium toxicity are ameliorated in calcium-rich soils. It seems possible that a primary toxic effect of aluminium might be to impair calcium-mediated plant defence responses against low pH.     

A New Technology for Applanation Free Corneal Trephination: The Picosecond Infrared Laser (PIRL)

The impact of using a Femtosecond laser on final functional results of penetrating keratoplasty is low. The corneal incisions presented here result from laser ablations with ultrafast desorption by impulsive vibrational excitation (DIVE). The results of the current study are based on the first proof-of-principle experiments using a mobile, newly introduced picosecond infrared laser system, and indicate that wavelengths in the mid-infrared range centered at 3 μm are efficient for obtaining applanation-free deep cuts on porcine corneas.     

New Type of Papillomavirus and Novel Circular Single Stranded DNA Virus Discovered in Urban Rattus norvegicus Using Circular DNA Enrichment and Metagenomics

Rattus norvegicus (R. norvegicus) are ubiquitous and their presence has several effects on the human populations in our urban areas on a global scale. Both historically and presently, this close interaction has facilitated the dissemination of many pathogens to humans, making screening for potentially zoonotic and emerging viruses in rats highly relevant. We have investigated faecal samples from R. norvegicus collected from urban areas using a protocol based on metagenomic enrichment of circular DNA genomes and subsequent sequencing. We found a new type of papillomavirus, with a L1 region 82% identical to that of the known R. norvegicus Papillomavirus 2. Additionally, we found 20 different circular replication associated protein (Rep)-encoding single stranded DNA (CRESS-DNA) virus-like genomes, one of which has homology to the replication-associated gene of Beak and feather disease virus. Papillomaviruses are a group of viruses known for their carcinogenic potential, and although they are known to infect several different vertebrates, they are mainly studied and characterised in humans. CRESS-DNA viruses are found in many different environments and tissue types. Both papillomaviruses and CRESS-DNA viruses are known to have pathogenic potential and screening for novel and known viruses in R. norvegicus could help identify viruses with pathogenic potential.     

The 1-Hz fluorometer: A new approach to fast and sensitive long-term studies of active chlorophyll and environmental influences

A new instrument for environmental monitoring, called at 1-Hz fluorometer, provides two modes of application. First, it enables a quantitative determination of algal concentrations down to 20 ng/l. Second, it can be used as a biosensor for changes in environmental conditions. The distinction between the signals from living chlorophyll-containing algae and other fluorescent material is achieved by using two modulated light-sources resulting in a mean fluence rate of 200 μE. The measuring light induces changes in chlorophyll fluorescence (yield) with a frequency of 1 kHz, and the actinic light modulates the redox state of the quenchers of PS II with a frequency of 1 Hz. This leads to a modulation of the yield which is detected by two phase-sensitive rectifiers (double correlation). Measurements from different sites in a river, and in the Baltic and North Seas, show that correction by the built-in simultaneously-measured attenuation is necessary in order to obtain values which are identical with those determined by a photometric analysis (Uvikon 860). This applies if the transmission becomes less than about 95%. Suspensions ofDunaliella salina exposed to ammonia and phosphate were used for illustrating the usage for environmental monitoring. It is shown that this system can measure changes in the chlorophyll fluorescence of living algae caused by changes in concentration of ammonia down to 1 μg/l and of phosphate down to 10 μg/l.