Arguments for and against self and non-self root recognition in plants

Root–root interaction research gained more and more attention over the past few years. Roots are pivotal for plant survival because they ensure uptake of water and nutrients. Therefore, detection of adjacent roots might lead to competitive advantages. Several lines of experimental evidence suggest that roots have ways to discriminate non-related roots, kin, and—importantly—that they can sense self/non-self roots to avoid intra-plant competition. In this mini-review, the existence of self/non-self recognition in plant roots will be discussed and the current knowledge on the mechanisms that could be involved will be summarized. Although the process of identity recognition is still not completely understood, interesting data are available and emerging new technologies will certainly aid to better understand this research field that can have an important biological, ecological, and agricultural impact

THE IMPACT OF COVID-19 ON TEACHER INTERACTIONS WITH STUDENTS WITH SPECIAL NEEDS

This qualitative, phenomenological research study was designed to study the impact that the COVID-19 pandemic had on teacher interactions with students with special needs during the mandatory school closures that took place during March of 2020. This study consisted of seven interviews with special education teachers, from three different districts, located in Menominee and Delta counties in the Upper Peninsula of Michigan. Participant responses to interview questions (See Appendix C), revealed six common themes: Inability to consistently connect with students and a lack of participation amongst students. Lack of training and no prior online teaching experience. Lack of available technology and connectivity available for all students. Lack of ordinary routine and direct instruction. Academic and emotional regressions in students. Having resources that align with the online platforms that districts are using With the findings of this study, school leaders may be able to develop policies that will better serve students with special needs in the event of future long-term school closures

Rapid toxicity assessment of six antifouling booster biocides using a microplate-based chlorophyll fluorescence in Undaria pinnatifida gametophytes

Biocides of antifouling agents can cause problems in marine ecosystems by damaging to non-target algal species. Aquatic bioassays are important means of assessing the quality of water containing mixtures of contaminants and of providing a safety standard for water management in an ecological context. In this study, a rapid, sensitive and inexpensive test method was developed using free-living male and female gametophytes of the brown macroalga Undaria pinnatifida. A conventional fluorometer was employed to evaluate the acute (48 h) toxic effects of six antifouling biocides: 4,5-Dichloro-2-octyl-isothiazolone (DCOIT), diuron, irgarol, medetomidine, tolylfluanid, zinc pyrithione (ZnPT). The decreasing toxicity in male and female gametophytes as estimated by EC50 (effective concentration at which 50% inhibition occurs) values was: diuron (0.037 and 0.128 mg l(-1), respectively) > irgarol (0.096 and 0.172 mg l(-1), respectively) > tolylfluanid (0.238 and 1.028 mg l(-1), respectively) > DCOIT (1.015 and 0.890 mg l(-1), respectively) > medetomidine (12.032 and 12.763 mg l(-1), respectively). For ZnPT, 50% fluorescence inhibition of U. pinnatifida gametophytes occurred at concentrations above 0.4 mg l(-1). The Undaria method is rapid, simple, practical, and cost-effective for the detection of photosynthesis-inhibiting biocides, thus making a useful tool for testing the toxicity of antifouling agents in marine environments

Increased protein stability and decreased protein turnover in the Caenorhabditis elegans Ins/IGF-1 daf-2 mutant

In Caenorhabditis elegans, cellular proteostasis is likely essential for longevity. Autophagy has been shown to be essential for lifespan extension of daf-2 insulin/IGF mutants. Therefore, it can be hypothesized that daf-2 mutants achieve this phenotype by increasing protein turnover. However, such a mechanism would exert a substantial energy cost. By using classical S-35 pulse-chase labeling, we observed that protein synthesis and degradation rates are decreased in young adults of the daf-2 insulin/IGF mutants. Although reduction of protein turnover may be energetically favorable, it may lead to accumulation and aggregation of damaged proteins. As this has been shown not to be the case in daf-2 mutants, another mechanism must exist to maintain proteostasis in this strain. We observed that proteins isolated from daf-2 mutants are more soluble in acidic conditions due to increased levels of trehalose. This suggests that trehalose may decrease the potential for protein aggregation and increases proteostasis in the daf-2 mutants. We postulate that daf-2 mutants save energy by decreasing protein turnover rates and instead stabilize their proteome by trehalose

The Effects of Recycling on the Hygroexpansivity of Thermomechanical Pulp

The objectives of this thesis were 1) to determine the effects of recycling and increased drying temperature on the hygroexpansivity of the fibers and 2) to investigate the role of beating on the hygroexpansivity of the fibers. A never-dried thermomechanical pulp was obtained and separated into three samples. Handsheets were produced, dried, and placed in a conditioning room. Sample one was air dried (77°F), sample two was dried at 155°F and sample three was dried at 250°F, respectively. Five handsheet samples at each varying temperature were taken and the hygroexpansivity was tested and calculated for each sheet using the equation BC= ΔL/L. B is the hygroexpansivity coefficient, C is the moisture content determined by W-Wo/Wo, where W is final weight of saturated sample after hygroexpansivity test and Wo is initial O.D. weight of sample. ΔL/L is defined as the strain of the sample. After testing the hygroexpansivity of the sheets, the samples were repulped in a British Disintegrator to resemble the recycling process. Once disintegrated, a series of handsheets were again made for each respective temperature, continuing for three recycles. The effects of beating on the hygroexpansivity of the sheet were also investigated. The freeness of the thermomechanical pulp was initially determined and handsheets were made and dried at 250°F, then tested for hygroexpansivity. Once tested, the sheets were disintegrated following the aforementioned process. The pulp was then taken to a PFI mill and beaten to the initial freeness of the pulp before recycling occurred. Again, after the series of recycling and beating, the sheets were tested for hygroexpansivity. Four recycles were completed. It was determined that as the number of recycles and drying temperature increased, the hygroexpansivity of the sheets decreased, becoming more dimensionally stable. Recycling and drying caused an increase of the crystalline region and hardening of the fibers. The fiber absorbed less water, therefore, causing the sheet to react less to the rising humidity. The effects of beating on the hygroexpansivity were very peculiar. In the past, when chemical pulps have been tested the hygroexpansivity of the pulp increased with beating due to fibrillization of the fibers exposing the region of the fiber that is hydrophilic causing dimensional instability. For the mechanical pulp tested, as beating was instituted, the hygroexpansivity of the sheet actually decreased, meaning increased dimensional stability. This trend was true for each of the recycles, which is exactly opposite of what is believed. This may be attributed to the lignin and hemicelluloses present in mechanical pulps, which are not present in chemical pulps

Low flow extracorporeal CO2 removal in ARDS patients : a prospective short-term crossover pilot study

Background: Lung protective mechanical ventilation (MV) is the corner stone of therapy for ARDS. However, its use may be limited by respiratory acidosis. This study explored feasibility of, effectiveness and safety of low flow extracorporeal CO2 removal (ECCO2R). Methods: This was a prospective pilot study, using the Abylcap (R) (Bellco) ECCO2R, with crossover off-on-off design (2-h blocks) under stable MV settings, and follow up till end of ECCO2R. Primary endpoint for effectiveness was a 20% reduction of PaCO2 after the first 2-h. Adverse events (AE) were recorded prospectively. We included 10 ARDS patients on MV, with PaO2/FiO(2) = 5 cmH(2)O, FiO(2) titrated to SaO(2) 88-95%, plateau pressure >= 28 cmH(2)O, and respiratory acidosis (pH < 7.25). Results: After 2-h of ECCO2R, 6 patients had a >= 20% decrease in PaCO2 (60%); PaCO2 decreased 28.4% (from 58.4 to 48. 7 mmHg, p = 0.005), and pH increased (1.59%, p = 0.005). ECCO2R was hemodynamically well tolerated. During the whole period of ECCO2R, 6 patients had an AE (60%); bleeding occurred in 5 patients (50%) and circuit thrombosis in 3 patients (30%), these were judged not to be life threatening. Conclusions: In ARDS patients, low flow ECCO2R significantly reduced PaCO2 after 2 h, Follow up during the entire ECCO2R period revealed a high incidence of bleeding and circuit thrombosis