Island properties dominate species traits in determining plant colonizations in an archipelago system

The extrinsic determinants hypothesis emphasizes the essential role of environmental heterogeneity in species’ colonization. Consequently, high resident species diversity can increase community susceptibility to colonizations because good habitats may support more species that are functionally similar to colonizers. On the other hand, colonization success is also likely to depend on species traits. We tested the relative importance of environmental characteristics and species traits in determining colonization success using census data of 587 vascular plant species collected about 70 yr apart from 471 islands in the archipelago of SW Finland. More specifically, we explored potential new colonization as a function of island properties (e.g. location, area, habitat diversity, number of resident species per unit area), species traits (e.g. plant height, life-form, dispersal vector, Ellenberg indicator values, association with human impact), and species’ historical distributions (number of inhabited islands, nearest occurrence). Island properties and species’ historical distributions were more effective than plant traits in explaining colonization outcomes. Contrary to the extrinsic determinants hypothesis, colonization success was neither associated with resident species diversity nor habitat diversity per se, although colonization was lowest on sparsely vegetated islands. Our findings lead us to propose that while plant traits related to dispersal and establishment may enhance colonization, predictions of plant colonizations primarily require understanding of habitat properties and species’ historical distributions.     

Basal ganglia hemorrhage in a case report following spinal surgery

Background

Intracranial hemorrhage is a rare but potentially severe complication of spinal surgery. Most reported post-operative ICH cases consist of cerebellar hemorrhage. There are fewer reported cases of supratentorial ICH following spinal surgery.

Case presentation

A 56-year-old woman underwent spinal surgery complicated by bilateral supratentorial intraparenchymal basal ganglia hemorrhage with both intraventricular extension and subarachnoid hemorrhage in both cerebral hemispheres.

Conclusion

The occurrence of neurological deterioration post-operatively following spinal surgery should alert physicians to the possibility of intracranial hemorrhage in order to facilitate rapid and optimal management. To our knowledge, this is the first case reporting basal ganglia hemorrhage following spinal surgery. Moreover, consideration should be given to the possibility of this complication prior to recommendation of elective spinal surgery.

     

Clinical utility of tumor genomic profiling in patients with high plasma circulating tumor DNA burden or metabolically active tumors

Background

This retrospective study was undertaken to determine if the plasma circulating tumor DNA (ctDNA) level and tumor biological features in patients with advanced solid tumors affected the detection of genomic alterations (GAs) by a plasma ctDNA assay.

Method

Cell-free DNA (cfDNA) extracted from frozen plasma (N?=?35) or fresh whole blood (N?=?90) samples were subjected to a 62-gene hybrid capture-based next-generation sequencing assay FoundationACT. Concordance was analyzed for 51 matched FoundationACT and FoundationOne (tissue) cases. The maximum somatic allele frequency (MSAF) was used to estimate the amount of tumor fraction of cfDNA in each sample. The detection of GAs was correlated with the amount of cfDNA, MSAF, total tumor anatomic burden (dimensional sum), and total tumor metabolic burden (SUVmax sum) of the largest ten tumor lesions on PET/CT scans.

Results

FoundationACT detected GAs in 69 of 81 (85%) cases with MSAF >?0. Forty-two of 51 (82%) cases had ≥?1 concordance GAs matched with FoundationOne, and 22 (52%) matched to the National Comprehensive Cancer Network (NCCN)-recommended molecular targets. FoundationACT also detected 8 unique molecular targets, which changed the therapy in 7 (88%) patients who did not have tumor rebiopsy or sufficient tumor DNA for genomic profiling assay. In all samples (N?=?81), GAs were detected in plasma cfDNA from cancer patients with high MSAF quantity (P?=?0.0006) or high tumor metabolic burden (P?=?0.0006) regardless of cfDNA quantity (P?=?0.2362).

Conclusion

This study supports the utility of using plasma-based genomic assays in cancer patients with high plasma MSAF level or high tumor metabolic burden.

     

Phycoremediation potential,physiological, and biochemical response of <Emphasis Type="Italic">Amphora subtropica</Emphasis> and <Emphasis Type="Italic">Dunaliella</Emphasis> sp. to nickel pollution

Metal pollution can produce many biological effects on aquatic environments. The marine diatom Amphora subtropica and the green alga Dunaliella sp. possess a high metal absorption capacity. Nickel (Ni) removal by living cells of A. subtropica and Dunaliella sp. was tested in cultures exposed to different Ni concentrations (100, 200, 300, and 500 mg L^?1). The amount of Ni removed by the microalgae increased with the time of exposure and the initial Ni concentration in the medium. The metal, which was mainly removed by bioadsorption to Dunaliella sp. cell surfaces (93.63% of total Ni (for 500 mg Ni L^?1) and by bioaccumulation (80.82% of total Ni (for 300 mg Ni L^?1) into Amphora subtropica cells, also inhibited growth. Exposure to Ni drastically reduced the carbohydrate and protein concentrations and increased total lipids from 6.3 to 43.1 pg cell^?1, phenolics 0.092 to 0.257 mg GAE g^?1 (Fw), and carotenoid content, from 0.08 to 0.59 mg g^?1 (Fw), in A. subtropica. In Dunaliella sp., total lipids increased from 26.1 to 65.3 pg cell^?1, phenolics from 0.084 to 0.289 mg GAE g^?1 (Fw), and carotenoid content from 0.41 to 0.97 mg g^?1 (Fw). These compounds had an important role in protecting the algae against ROS generated by Ni. In order to cope with Ni stress shown by the increase of TBARS level, enzymatic (SOD, CAT, and GPx) ROS scavenging mechanisms were induced.     

A modeling procedure to predict cancer risks associated with inhalable oil dust from Kuwait oil lakes

A model was constructed to estimate cancer risks associated with PM₁₀‐bound polycydic aromatic hydrocarbons (PAHs) from Kuwait oil lakes. The design of the risk model was based on a conceptual “chain of events”; leading from levels of PAH compounds in oil lakes, erosion of oil dust and input into the atmosphere, to contaminant concentration in air, to actual human exposure in residential areas. Uncertainties in the “chain of events”; model were addressed using Monte Carlo techniques. To identify the exposure duration of concern [duration beyond which risk becomes unacceptable (i.e. Risk > 10^‐6)], four exposure durations were tested 10, 20, 40, 70 years. 40 years was identified to be the exposure duration of concern based on the 95th percen‐tile of the risk distribution. As a result, the acceptability of risk was specified in terms of a single constraint on the 95^th percentile of the risk distribution evaluated after 40 years of exposure: 0 < Risk (40 y)₀.₉₅ ≤ 10^‐6. Based on this constraint, it was estimated that a removal rate of 217, 793.27 m³/year to be an adequate action for risk management. The northern oil lakes were identified as the lakes of most concern when inhalation exposures are considered.     

Qualitative behavior of stage-structured populations: application to structural validation

 The transient behavior of a class of nonlinear differential systems representing stage-structured populations is studied. The qualitative dynamics are described in terms of succession of extrema for the state variables, or for the integrated difference between two trajectories. The rules giving the possibilities of extrema are derived, they characterize the classical stage-structured models. These rules can be compared with experiments to validate the structure of the model. An explanation for the disagreement of this transition scheme with some experiments could be an unexpected interaction with another variable. A new model taking the interaction into account thus engenders new transition rules, which are to be compared with experiments. These results are illustrated with experiments on copepods, showing how the qualitative experimental features can help the construction and the validation of the models. Received: 13 May 1996 / Revised version: 20 March 1998     

The DNA-Delay Mutants of Bacteriophage T4

Mutants of phage T4 defective in genes 39, 52, 58-61, and 60 (the DNA delay or DD genes) are characterized by a delay in phage DNA synthesis during infection of a nonpermissive Escherichia coli host. Amber (am) mutants defective in these genes yield burst sizes varying from 30 to 110 at 37 C in E. coli lacking an am suppressor. It was found that when DD am mutants are grown on a non-permissive host at 25 C, rather than at 37 C, phage yield is reduced on the average 61-fold. At 25 C incorporation of labeled thymidine into phage DNA is also reduced to 3 to 10% of wild-type levels. Mutants defective in the DD genes were found to promote increased recombination as well as increased base substitution and addition-deletion mutation. These observations indicate that the products of the DD genes are necessary for normal DNA synthesis. The multiplication of the DD am mutants on an Su⁻ host at 37 C is about 50-fold inhibited if prior to infection the host cells were grown at 25 C. This suggests that a compensating host function allows multiplication of DD am mutants at 37 C in the Su⁻ host, and that this function is active in cells grown at 37 C prior to infection, but is inactive when the prior growth is at 25 C. Further results are described which suggest that the products of genes 52, 60, and 39 as well as a host product interact with each other.     

Feulgen Hydrolysis with Phosphoric Acid

Sections from rat tissues fixed in a 10% solution of formalin in 90% alcohol were treated with phosphoric acid in concentrations varying from 30 to 85% at room temperature (28°), and subsequently stained with the Schiff reagent. Intense staining of the nuclear material was obtained in 5 to 15 minutes when 40 to 75% phosphoric acid was used. The intense staining after the higher concentrations of phosphoric acid may be due to the low concentration of water present, thus minimizing diffusion. The nucleoli in the rat-liver cells were well stained, especially the peripheral portion. The nucleoli of nerve cells, however, were only faintly stained and the Nissl substance was completely negative. The accompanying plate of photomicrographs shows the nuclei stained by this method in the Graafian follicle, the liver, intestinal villi of the rat and a metastatic carcinoma in the human pituitary.