Mapping riparian condition indicators in a sub-tropical savanna environment from discrete return LiDAR data using object-based image analysis

Mapping, monitoring and managing the environmental condition of riparian zones are major focus areas for local and state governments in Australia. New remotely sensed data techniques that can provide the required mapping accuracies, complete spatial coverage and processing and mapping transferability are currently being developed for use over large spatial extents. The research objective was to develop and apply an approach for mapping riparian condition indicators using object-based image analysis of airborne Light Detection and Ranging (LiDAR) data. The indicators assessed were: streambed width; riparian zone width; plant projective cover (PPC); longitudinal continuity; coverage of large trees; vegetation overhang; and stream bank stability. LiDAR data were captured on 15 July 2007 for two 5 km stretches along Mimosa Creek in Central Queensland, Australia. Field measurements of riparian vegetation structural and landform parameters were obtained between 28 May and 5 June 2007. Object-based approaches were developed for mapping each riparian condition indicator from the LiDAR data. The validation and empirical modelling results showed that the object-based approach could be used to accurately map the riparian condition indicators (R² = 0.99 for streambed width, R² = 0.82 for riparian zone width, R² = 0.89 for PPC, R² = 0.40 for bank stability). These research findings will be used in a 26,000 km mapping project assessing riparian vegetation and physical form indicators from LiDAR data in Victoria, Australia.     

The origin and development of somatic embryos following cryopreservation of an embryogenic suspension culture ofPicea sitchensis

Summary The development of somatic embryos in an embryogenic suspension culture ofPicea sitchensis was followed every day for two weeks after thawing from liquid nitrogen (LN₂). Only a few cells, primarily located at the periphery of the embryonic region of the embryos, survived cryopreservation in LN₂. Surviving cells were classified into two groups: embryogenic cells (EC) and non-embryogenic cells (NEC), based on their morphology and embryogenic competence. The dense cytoplasmic EC underwent organized growth and differentiation with first divisions occurring after 24 h, and embryo formation 6–8 days after thawing from LN₂. No evidence of asymmetrical divisions or free-nuclear stages was found during somatic embryo formation. NEC had less dense cytoplasm with numerous small vacuoles. One to five days after thawing the NEC became progressively more vacuolated and elongated. Histological examination revealed no mitotic activity in NEC, and six days after thawing NECs were seen as single cells or unorganized cell aggregates. Two weeks after thawing the appearance of the cryopreserved cultures was comparable to that of the untreated cultures.Abbreviations EC embryogenic cells - ECC embryogenic cell clusters - FDA fluorescein diacetate - GMA glycol methacrylate - LN₂ liquid nitrogen (–196°C) - NEC non-embryogenic cells     

The cDNA sequence for the protein-tyrosine kinase substrate p36 (calpactin I heavy chain) reveals a multidomain protein with internal repeats

We have isolated and sequenced a full-length cDNA clone for the protein-tyrosine kinase substrate p36 (calpactin I heavy chain). This sequence predicts a 339 amino acid (Mr 38,493) protein containing an N-terminal region of 20 amino acids, known to interact with a 10 kd protein (light chain), and a C-terminal region, found to contain two Ca2+/phospholipid-binding sites, that can be aligned as four 70 amino acid repeats. A single p36 gene was detected in the mouse genome, and a major p36 mRNA of 1.6 kb was found to be expressed in different mouse tissues. Unexpectedly, p36 and the phospholipase A2 inhibitor lipocortin I were found to be 50% identical in sequence over the C-terminal 300 residues. The function of p36 and its relation to other proteins are discussed.     

NMR and interval PLS as reliable methods for determination of cholesterol in rodent lipoprotein fractions

Risk of cardiovascular disease is related to cholesterol distribution in different lipoprotein fractions. Lipoproteins in rodent model studies can only reliably be measured by time- and plasma-consuming fractionation. An alternative method to measure cholesterol distribution in the lipoprotein fractions in rat plasma is presented in this paper. Plasma from two rat studies (n = 68) was used in determining the lipoprotein profile by an established ultracentrifugation method and proton nuclear magnetic resonance (NMR) spectra of replicate samples was obtained. From the ultracentrifugation reference data and the NMR spectra, an interval partial least-square (iPLS) regression model to predict the amount of cholesterol in the different lipoprotein fractions was developed. The relative errors of the prediction models were between 12 and 33% and had correlation coefficients (r) between 0.96 and 0.84. The models were tested with an independent test set giving prediction errors between 19 and 46% and r between 0.96 and 0.76. Prediction of High, Low and Very Low Density Lipoprotein (HDL, LDL and VLDL) and total cholesterol was conducted in a study where rats had been supplemented with two doses of air-dried apple-powder. No significant difference in LDL, VLDL and total cholesterol was observed between the groups. The high apple-powder (20%) group had significantly lower HDL cholesterol (11%, P = 0.0452) than the control group. It is concluded that the iPLS approach yielded excellent regression models and thus univocal established chemometric analysis of NMR spectra of rat plasma as a strong and efficient way to quantify lipoprotein fractions in rat studies.     

Uprooting and Burial of Invasive Alien Plants: A New Tool in Coastal Restoration?

Invasive alien plants are a problem for conservation management, and control of these species can be combined with habitat restoration. Subsoil burial of uprooted plants is a new method of mechanical control, which might be suitable in disturbed habitats. The method was tested in Rosa rugosa (Japanese Rose), an invasive shrub in north‐western Europe with negative effects on coastal biodiversity. Two months after uprooting and burial in dunes of north‐eastern Denmark, 89% of the 58 shrubs resprouted from roots and rhizomes; on average 41 resprouts per shrub. Resprout density was twice as high at former shrub margins compared with the center; resprouts were taller and originated from more superficial soil layers at the margin than in the center. Resprouting was negatively correlated with fragment depth, and no resprouts were observed from greater than 15 cm depth. The number of resprouts increased with fragment dry mass (0.5–168.5 g). After 18 months with harrowing the species was still resprouting, flowering, and fruiting, albeit with no difference between shrub margin and center. Resprouts were taller (26 cm) and coverage was higher (0–4%) after two compared with three times harrowing, whereas no difference was found in cover of native dune species (1–5%). The results show that even small fragments of R. rugosa resprout, and that resprouting persists despite repeated harrowing. Thus, careful subsoil burial of all fragments is necessary, special attention should be paid to the shrub margin, and follow‐up treatments are needed. The effectiveness of the burial method is discussed for restoration of coastal dunes.     

Lymphokine regulation of human lymphocyte proliferation: Formation of resting G0 cells by removal of interteukin 2 in cultures of proliferating T lymphocytes

The question of whether lymphocytes which have once been activated and have completed one or several cell cycle(s) can return to the G₀ phase and stay ready for a new activation (G₀-G₁ transition), rather than simply die, was investigated. To do so interleukin 2 (IL-2) was removed from cultures of continuously proliferating human T lymphocytes and the formation of resting (G₀) cells was measured. Kinetic analyses in freshly prepared peripheral blood lymphocytes (PBL) revealed that the onset of detectable RNA synthesis and the appearance of structures binding the anti-Tac antibody occurred simultaneously. This allowed the expansion of the definition of G₀ T lymphocytes as cells having a low RNA (and DNA) content, and no Tac antigen. When cultured human T cells proliferating continuously by means of IL-2 were characterized in terms of their distribution in the cell cycle, 7 days after the initial PHA stimulation, it could be demonstrated that very few cells were in the G₀ phase, supporting the concept of direct S/G₂/M-G₁ transition. However, when IL-2 was removed from the cultures, the [³H]thymidine incorporation per 10⁴ cells and correspondingly the number of cells in the S/G₂/M and G₁ phases were reduced drastically and during the following 72-hr period, the number of G₀ cells increased markedly. Restimulation of such in vitro formed G₀ cells, under conditions permitting observation of their shift from the G₀ to G₀ phase, demonstrated that most cells could respond normally. Based on these observations, it was concluded that IL-2 not only ensures T-lymphocyte survival and proliferation, but IL-2 starvation induces many continuously proliferating T lymphocytes to stop cycling and to return to the G₀ phase of the cell cycle where they remain functional.     

Analysis of cervical smears obtained within three years of the diagnosis of invasive cervical cancer

The cytologic histories of 376 women presenting with invasive carcinoma of the cervix were analyzed. In total, 202 (53.7%) of these women had had 355 smears taken during the three years preceding presentation. All 320 smears with an original cytologic diagnosis of less than cancer were reviewed. The original cytologic diagnosis was low in 95 (30.6%) of 310 adequate smears. Originally, 96 (30.9%) of the adequate smears were evaluated as negative; at review, only 55 (17.5%) of the adequate smears were evaluated as negative. Comparing the review diagnoses to the 355 total smears, the rates of negative smears were 13.5% (42 of 310) for squamous-cell carcinoma, 30.0% (12 of 40) for adenocarcinoma and 20.0% (1 of 5) for adenosquamous carcinoma (P less than .05). The cellular composition of the smear was significantly related to the cytologic detection of abnormalities: endocervical cylindrical and/or metaplastic cells were seen in only 45.5% of smears diagnosed as negative, but in 84.4% and 97.8% of smears diagnosed as atypia and cervical intraepithelial neoplasia, respectively P less than .00001). Smears without endocervical cells should be considered inadequate and should be repeated.     

Familial Hemophagocytic Lymphohistiocytosis Type 5 (FHL-5) Is Caused by Mutations in Munc18-2 and Impaired Binding to Syntaxin 11

Rapid intracellular transport and secretion of cytotoxic granules through the immunological synapse requires a balanced interaction of several proteins. Disturbance of this highly regulated process underlies familial hemophagocytic lymphohistiocytosis (FHL), a genetically heterogeneous autosomal-recessive disorder characterized by a severe hyperinflammatory phenotype. Here, we have assigned FHL-5 to a 1 Mb region on chromosome 19p by using high-resolution SNP genotyping in eight unrelated FHL patients from consanguineous families. Subsequently, we found nine different mutations, either truncating or missense, in STXBP2 in twelve patients from Turkey, Saudi Arabia, and Central Europe. STXBP2 encodes syntaxin binding protein 2 (Munc18-2), involved in the regulation of vesicle transport to the plasma membrane. We have identified syntaxin 11, a SNARE protein mutated in FHL-4, as an interaction partner of STXBP2. This interaction is eliminated by the missense mutations found in our FHL-5 patients, which leads to a decreased stability of both proteins, as shown in patient lymphocytes. Activity of natural killer and cytotoxic T cells was markedly reduced or absent, as determined by CD107 degranulation. Our findings thus identify a key role for STXBP2 in lytic granule exocytosis.