Derivation of Plant Cell Wall Water Content by Examination of the Water-Holding Capacity of Membrane-Disrupted Tissues10

Plant cell lumina are several orders of magnitude larger thancell wall pores. If the membranes of the plant sample are disruptedand the tissue dried out, a value should be reached at whichthe cell lumina have drained but the cell walls remain relativelyhydrated. The water content of membrane-disrupted tissues atlow may, therefore, serve as a good approximation of plantcell wall water content (CW). The relationship between and water content of membrane-disruptedtissues was measured for four grass spaces over the range of0 to –40 MPa. It was found that most water loss occurredabove a of – 10 MPa. CW was estimated from the watercontent of membrane-disrupted tissues at lower and it was foundthat there was very little intra-or intraspecific variabilityin CW estimates when water content was expressed as a percentagedry weight of the tissue. This is in contrast to the high variabilityin CW estimated from the analysis of inverse water potential—watercontent (IP—WC) curves measured with the thermocouplepsychrometer. Applications of the membrane-disruption methodof estimating CW of plant tissue are discussed. Key words: Cell wall water, thermocouple psychrometer, membrane-disruption     

Development of microsatellites for the invasive riparian plant Impatiens glandulifera (Himalayan balsam) using intersimple sequence repeat cloning

Impatiens glandulifera (Himalayan balsam) is an invasive riparian plant species that can outcompete native perennials. Population genetic data on dispersal may aid in the management of invasive species, so we have developed microsatellite markers for this significant invader using an intersimple sequence repeat (ISSR)‐based cloning method. Eight polymorphic markers displayed between two and five alleles, with overall levels of observed and expected heterozygosities ranging from 0.0500 to 0.7500 and from 0.1449 to 0.7692, respectively.     

Fighting the stigma caused by mental disorders: past perspectives,present activities,and future directions

People who live with mental illnesses are among the most stigmatized groups in society. In 1996, in recognition of the particularly harsh burden caused by the stigma associated with schizophrenia, the WPA initiated a global anti-stigma program, Open-the-Doors. In 2005, a WPA Section on Stigma and Mental Health was created, with a broader mandate to reduce stigma and discrimination caused by mental disabilities in general. In light of these impor-tant developments, and the growing public health interest in stigma reduction, this paper reflects on the past perspectives that have led us to our current position, reviews present activities and accomplishments, and identifies challenges that the Section members will face in their future efforts to reduce the stigma caused by mental disorders.     

Biological monitoring of water quality in Australia: Workshop summary and future directions

Abstract Biological methods are widely accepted in water quality monitoring programmes worldwide; however, some concern remains over their effectiveness in predicting the effects of contaminants on aquatic ecosystems. While the so-called‘early warning’ approaches, such as bioassays and biomarkers, have been used in Australia to demonstrate mechanisms of toxic action and exposure to contaminants, as elsewhere, little attempt has been made to link observed effects at these lower levels of biological organization to real impacts on aquatic systems. The ecological consequences of exposure to contaminants is undoubtedly best studied at higher levels of biological organization (i. e. at the population or community level). However, monitoring aquatic communities is labour intensive and inadequate for the early detection of impacts. Research is needed to identify links between the bioassessment measures used, so that changes at the lowest biological level (e. g. using biomarkers and bioassays) can be translated into likely‘real’ impacts on the aquatic system, as measured at the population or community level. Monitoring the genetic structure of populations of aquatic organisms, particularly invertebrates, may provide a potential link between subtle effects observed in bioassay tests and subsequent changes in population density and/or community structure. A streamlined approach to monitoring changes at the community level needs to be developed to improve predictive ability and to make this approach more responsive to the early detection and prevention of unacceptable impacts. In addition, research on the use of ecosystem level parameters, such as production/respiration ratios or community metabolism, should be undertaken to determine their suitability for routine biomonitoring of water quality in Australian inland waters.     

Prey selection and annual harvest of game in a rural Zambian community

The selection and hunting patterns of Valley Bisa hunters were studied as part of a broader ecological investigation of human communities between the two sections of the Luangwa Valley Game Reserves in Zambia. This article provides information on the frequency and duration of hunts recorded for 1 year, yields of individual hunters, prey selection, frequency of kill, community meat supplies and the effect of human and carnivore predation on population levels on a study area of some 155 km². Individuals who hunted were classified into four categories–resident, transient, occasional, and official, dependent upon their role in the community, length of time spent on the study area and their village of primary residence. The most frequent hunters were residents followed in rank order by officials, transients and occasionals. Hunts were of shorter duration during the dry season, when game was close to villages, than during the wet season. Generally hunters who owned or had access to modern weapons were more successful in their pursuits of game than were those who used muzzle-loading guns. A total of 27 451 kg of meat (carcass yield) was made available to 466 local residents during the course of the year; 40% of this was attributed to the activities of the game guards. Valley Bisa hunters killed primarily buffalo, impala, warthogs, and waterbuck; most of these were males and adults. The kills recorded for carnivores suggest that they took primarily female buffalo and zebra. There was no evidence to suggest that either type of predation was damaging to the game herds on the study area.     

Genomic dissection and prioritizing of candidate genes of QTL for regulating spontaneous arthritis on chromosome 1 in mice deficient for interleukin-1 receptor antagonist

Rheumatoid arthritis is a heterogeneous disease with clinical and biological polymorphisms. IL-1RN is a protein that binds to interleukin-1 (IL-1) receptors and inhibits the binding of IL-1-alpha and IL-1-beta. IL-1RN levels are elevated in the blood of patients with a variety of infectious, immune, and traumatic conditions. Balb/c mice deficient in IL-1ra (mouse gene of IL-1RN) develop spontaneous autoimmune arthritis while DBA/1 mice deficient in IL-1ra do not. Previously, we identified a major QTL that regulates the susceptibility to arthritis in Balb/c mice with IL-1ra deficiency. In this study, we found that the QTL may contain two peaks that are regulated by two sets of candidate genes. By haplotype analysis, the total genomic regions of candidate genes were reduced from about 19 Mbp to approximately 9 Mbp. The total number of candidate genes was reduced from 208 to 21.