TREATMENT OF RAT PROXIMAL AND DISTAL COLONIC CELLS WITH SODIUM ORTHOVANADATE ENHANCES THEIR ADHESION AND SURVIVAL IN PRIMARY CULTURE

We have studied the effect of sodium orthovanadate, an inhibitor of protein tyrosine phosphatases, on primary cultures of colonocytes and stromal cells. Everted proximal and distal colonic tissue of adult rats were disintegrated by a collagenase/dispase solution for 60 min at 37°C to prepare viable gland fragments and isolated cells. Cell preparations were inoculated onto plastic substratum or cytodex-3 microcarriers in a defined maintenance medium or in 1% fetal calf serum media. Incorporation of sodium orthovanadate (≥50 μm) in these media constantly enhanced the survival (cell enumeration and trypan blue exclusionP<0.05) and the adhesion (up to four-fold by crystal violet staining,P<0.01) of colonocytes (characterized by cytokeratin-18, transforming growth factor-α or alkaline phosphatase expression) and stromal cells. Removal of sodium orthovanadate from culture media restored cellular death processes. Incorporation of 10 mmn-butyric acid did not promote cell adhesion and survival except for distal cells exposed to 2 mm sodium orthovanadate. Besides studies in the regulation of anoikis in primary culture, the model will help to assay the influences of dietary and growth factors on the biology of non-cancerous colonic cells.     

How do different aspects of biodiversity change through time? A case study on an Australian bird community

The study of ecological communities through time can reveal fundamental ecological processes and is key to understanding how natural and human pressures will affect biodiversity. Most studies of ecological communities through time consider only one or a few summary measures (e.g. species richness, total abundance), which might neglect important aspects of community structure or function. We studied temporal variation in several measures of species diversity, size diversity, and species composition in an intensively sampled bird community to determine whether different biodiversity measures change synchronously. We used a novel function regression model, which supports the study of diversity measures that are distributions (e.g. species abundance distributions) alongside measures that are scalar values (e.g. species richness). Most diversity measures changed predictably within years, but inter‐annual changes in size diversity and species composition were not reflected in species diversity. Within and among years, there was considerable variation in distributional measures that was not captured in scalar measures. Predictable variation within years probably was related to seasonal variation in weather patterns or food availability, but variation in size diversity among years probably resulted from stochastic changes in species composition. These results suggest that species and size diversity may be decoupled, and that inferences on scalar diversity measures might not reflect fundamental changes to community structure or function. Our method supports the inclusion of size‐based measures and distributional measures in ecological analyses, and broader uptake of our approach is likely to provide new insight into the processes structuring ecological communities, and inform the links between structure and function in ecological communities.     

Best Practice Guidelines on Informed Consent for Weight Loss Surgery Patients

Objective: To provide evidence‐based guidelines on informed consent and the education that underlies it for legally competent, severely obese weight loss surgery (WLS) patients. Research Methods and Procedures: We conducted a systematic review of the scientific literature published on MEDLINE between 1984 and 2004. Three articles focused on informed consent for WLS; none was based on empirical studies. We summarized each paper and assigned evidence categories according to a grading system derived from established evidence‐based models. We also relied on informed consent and educational materials from six WLS programs in Massachusetts. All evidence is Category D. Recommendations were based on a review of the available literature, informed consent materials from WLS programs, and expert opinion. Results: This Task Group found that the informed consent process contributes to long‐term outcome in multiple ways but is governed by limited legal requirements. We focused our report on the legal and ethical issues related to informed consent, i.e., disclosure vs. comprehension. Recommendations centered on the importance of assessing patient comprehension of informed consent materials, the content of those materials, and the use of active teaching/learning techniques to promote understanding. Discussion: Although demonstrated comprehension is not a legal requirement for informed consent in Massachusetts or other states, the members of this Task Group found that the best interests of WLS patients, providers, and facilities are served when clinicians engage patients in active learning and collaborative decision making.     

Emergency relocation of a Purple Copper Butterfly colony during roadworks: Successes and lessons learned

Summary  In 2004, the Roads and Traffic Authority (RTA) undertook a road realignment project near Lidsdale in the Central Tablelands of New South Wales. However, the RTA had not detected a population of the threatened Purple Copper Butterfly within the footprint of the project. The RTA responded promptly when notified of the butterflies' presence by stopping works, and preparing and implementing a butterfly management programme. This programme included modifying the realignment (and reducing the development footprint), supplementary planting of habitat, habitat rehabilitation and translocation of individual caterpillars from within the final footprint area. These actions seem to have safeguarded the population at least in the short term; however, further active management of the site will be needed to ensure its long-term viability. The project reinforces the importance of thorough predisturbance assessment of a site at the early planning stages, and the results and observations could be particularly informative in planning for introduction, reintroduction and translocation proposals involving the Purple Copper Butterfly.     

Distinguishing past from present gene flow along and across a river: the case of the carnivorous marsupial (<Emphasis Type="Italic">Antechinus flavipes</Emphasis>) on southern Australian floodplains

Humans have altered many floodplain ecosystems around the world by clearing vegetation, building towns and regulating river flows. Studies discerning gene flow and population structure of floodplain-dwelling animals are rare yet are necessary for understanding the effects of human actions on native populations. In south-eastern Australia, the yellow-footed antechinus (Antechinus flavipes) is the only carnivorous marsupial on many lowland floodplains, yet our knowledge of impacts of human activities is limited. The control region of mitochondrial DNA and 11 microsatellite DNA markers were used to explore historic and current gene flow in A. flavipes across and along the Murray River. Simulations were carried out to test different migration models. We found evidence for historic gene flow along and across the river but inferred that small towns and farmland or cleared floodplain sections restricted current gene flow along the river. Populations along the river appear to be isolated, and should be maintained at large enough sizes to avoid genetic problems such as inbreeding depression and loss of evolutionary potential. We also investigated whether 50-year-long maintenance of high water levels for irrigation in summer, at the time of juvenile dispersal, has led to restrictions in gene flow across the river. We found no evidence for restrictions to gene flow across the river and suggest that large floods and dropping tree branches may aid dispersal across the river.     

Collapse of an avifauna: climate change appears to exacerbate habitat loss and degradation

Aim  We characterized changes in reporting rates and abundances of bird species over a period of severe rainfall deficiency and increasing average temperatures. We also measured flowering in eucalypts, which support large numbers of nectarivores characteristic of the region.
Location  A 30,000-km² region of northern Victoria, Australia, consisting of limited amounts of remnant native woodlands embedded in largely agricultural landscapes.
Methods  There were three sets of monitoring studies, pitched at regional (survey programmes in 1995–97, 2004–05 and 2006–08), landscape (2002–03 and 2006–07) and site (1997–2008 continuously) scales. Bird survey techniques used a standard 2-ha, 20-min count method. We used Bayesian analyses of reporting rates to document statistically changes in the avifauna through time at each spatial scale.
Results  Bird populations in the largest remnants of native vegetation (up to 40,000 ha), some of which have been declared as national parks in the past decade, experienced similar declines to those in heavily cleared landscapes. All categories of birds (guilds based on foraging substrate, diet, nest site; relative mobility; geographical distributions) were affected similarly. We detected virtually no bird breeding in the latest survey periods. Eucalypt flowering has declined significantly over the past 12 years of drought.
Main conclusions  Declines in the largest woodland remnants commensurate with those in cleared landscapes suggest that reserve systems may not be relied upon to sustain species under climate change. We attribute population declines to low breeding success due to reduced food. Resilience of bird populations in this woodland system might be increased by active management to enhance habitat quality in existing vegetation and restoration of woodland in the more fertile parts of landscapes.     

Understanding Fluctuations in Bobcat Harvest at the Northern Limit of Their Range

ABSTRACT In Quebec, Canada, harvest of bobcats (Lynx rufus) started to decline in 1985 and by 1991, harvest seasons were closed due to concerns of a perceived population decline. Since the closing of harvest season in 1991, the average temperature has increased, snow quantity has decreased, and important changes in agriculture and forest management have occurred. In light of changing conditions, the situation of Quebec bobcats needed reassessment. Thus, we analyzed harvest data to clarify the current status of bobcat populations in Quebec. From 1980 to 1991, bobcat harvest in Quebec was strongly correlated with bobcat harvest in Maine (USA), Nova Scotia (Canada), Ontario (Canada), and Vermont (USA). Extrapolations of harvest in Quebec relative to harvest in Maine, Ontario, Vermont, and Nova Scotia suggested an increase in number of bobcats after 1991. Mass of male and female bobcats before 1991 was less than mass of animals captured after 1991. Percentage of juveniles in the reported harvest before 1991 was higher than after 1991. However, percentage of males and litter sizes in the harvest did not differ before and after 1991. The geographic distribution of bobcats captured has gradually expanded after the closure of the harvest season. Our findings suggest that bobcat populations in Quebec have recovered from the 1985–1991 decline, and that the harvest season for this species could resume. This study also illustrates how managers can rely on data from neighboring jurisdiction to manage species when local harvest data is unavailable.     

Micropropagation by tissue culture triggers differential expression of infectious endogenous Banana streak virus sequences (eBSV) present in the B genome of natural and synthetic interspecific banana plantains

The genome of Musa balbisiana spp. contains several infectious endogenous sequences of Banana streak virus (eBSV). We have shown previously that in vitro micropropagation triggers the activation of infectious eBSOLV (endogenous sequences of Banana streak Obino l'Ewai virus ) in the synthetic tetraploid interspecific hybrid FHIA21 (AAAB). In this work, we show that another synthetic tetraploid (AAAB) hybrid and two natural triploid (AAB) plantains are equally prone to the activation of infectious eBSOLV during tissue culture. These results are a strong indication that such activation is a general phenomenon in interspecific Musa cultivars, whether synthetic or natural. We also report the first in-depth study of the correlation between the duration of tissue culture and the level of activation of infectious eBSOLV, and show that specific and common activation patterns exist in these banana plants. We hypothesize that these patterns result from the concomitant activation of infectious eBSOLV and a decrease in the virus titre in neoformed plantlets, resulting from cell multiplication outcompeting virus replication. We provide experimental data supporting this hypothesis. No activation of infectious eBSGFV (endogenous sequences of Banana streak Goldfinger virus) by tissue culture was observed in the two natural AAB plantain cultivars studied here, whereas such activation occurred in the AAAB synthetic hybrid studied. We demonstrate that this differential activation does not result from differences in the structure of eBSGFV, as all banana genomes harbour eaBSGFV-7.     

Carbon accumulation in agricultural soils after afforestation: a meta-analysis

Deforestation usually results in significant losses of soil organic carbon (SOC). The rate and factors determining the recovery of this C pool with afforestation are still poorly understood. This paper provides a review of the influence of afforestation on SOC stocks based on a meta-analysis of 33 recent publications (totaling 120 sites and 189 observations), with the aim of determining the factors responsible for the restoration of SOC following afforestation. Based on a mixed linear model, the meta-analysis indicates that the main factors that contribute to restoring SOC stocks after afforestation are: previous land use, tree species planted, soil clay content, preplanting disturbance and, to a lesser extent, climatic zone. Specifically, this meta-analysis (1) indicates that the positive impact of afforestation on SOC stocks is more pronounced in cropland soils than in pastures or natural grasslands; (2) suggests that broadleaf tree species have a greater capacity to accumulate SOC than coniferous species; (3) underscores that afforestation using pine species does not result in a net loss of the whole soil-profile carbon stocks compared with initial values (agricultural soil) when the surface organic layer is included in the accounting; (4) demonstrates that clay-rich soils (> 33%) have a greater capacity to accumulate SOC than soils with a lower clay content (< 33%); (5) indicates that minimizing preplanting disturbances may increase the rate at which SOC stocks are replenished; and (6) suggests that afforestation carried out in the boreal climate zone results in small SOC losses compared with other climate zones, probably because trees grow more slowly under these conditions, although this does not rule out gains over time after the conversion. This study also highlights the importance of the methodological approach used when developing the sampling design, especially the inclusion of the organic layer in the accounting.     

BIODIVERSITY RESEARCH: Diversity and distribution of macroinvertebrates in lentic habitats in massively altered landscapes in south‐eastern Australia

Aim We investigated whether faunas of lentic macroinvertebrates differed among two landscape types: (1) those that are largely covered in forests (presumed to be in a more pre‐human‐impact condition) and (2) those that are completely cleared for agricultural exploitation (massively altered). Location Five pairs of landscapes (each pair referred to as a region) – one of each landscape type – across a 30,000 km² region of north‐central Victoria, Australia. Methods Each individual waterbody was surveyed three times (austral spring 2006, autumn 2007, and spring 2007) for invertebrates. Waterbodies were characterized by measurements of static (e.g. abutting vegetation cover) and labile (e.g. pH) variables. Data were analysed using hierarchical Bayesian models of species richness, α‐ and β‐diversities and functional feeding groups. Assemblage composition was related to landscape and in‐waterbody characteristics. Results Neither measured, nor asymptotic estimates of, species richness differed among landscape types, notwithstanding consistent differences in in‐waterbody habitat characteristics among waterbodies in the two landscape types. There were no discernible differences in patterns of α‐ and β‐diversities at landscape scales relating to landscape type. Habitat diversity of waterbodies at the landscape scale did not affect β‐diversity, although distinct waterbodies within landscapes tended to have more distinct faunas. Main conclusions The lentic macroinvertebrate faunas are relatively homogeneous over the entire region, with little differentiation between wooded and cleared landscapes. The regional fauna may be a homogenized subset of native species, possibly arising from the huge numerical predominance of lentic habitats in agricultural landscapes producing ‘spill‐over’ effects into forested landscapes. Of taxa more frequently found in one or other landscape type, trophic group diversity was greater in forested landscapes.