Effects of osmotic- and high-light stresses on PSII efficiency of attached and detached leaves of three tree species adapted to different water regimes

Abscisic acid (ABA), an important chemical signal from roots, causes physiological changes in leaves, including stomata closure and photoprotection. Furthermore, endogenous ABA concentration in leaves and stomatal behavior vary with the species adapted to different water regimes. In this study, Ficus microcarpa, a hemiepiphyte, Salix warburgii, a hygrophyte, and Acacia confusa, a mesophyte, were used to elucidate the effects of leaf detachment on photosystem II (PSII) efficiency under osmotic- and high-light stresses. Results indicate that, under osmotic- and high-light stresses, PSII efficiency of the detached leaves was lower than that of the attached leaves for all three tree species, when compared at the same levels of stomatal resistance and leaf water potential. Exogenous ABA could mitigate the PSII efficiency decrease of detached F. microcarpa leaves under osmotic- and high-light stresses. Yet, the osmotic stress could raise endogenous ABA concentration in the attached, but not in the detached F. microcarpa leaves. In addition, partial root-zone drying exerted a significant effect on stomatal behavior but not on the water status of F. microcarpa leaves. These observations imply that the stronger ability of PSII in the attached leaves of F. microcarpa under osmoticand high-light stresses was probably due to the protective action of ABA from roots. On the contrary, endogenous ABA level of S. warburgii leaves was very low. In addition, partial root-zone drying produced no significant effect on its stomatal behavior. Therefore, PSII in attached S. warburgii leaves was possibly protected from the damaging effects of excess absorbed energy by signals other than ABA, which were transported from the roots

Anomalous Heat Conduction and Anomalous Diffusion in Low Dimensional Nanoscale Systems

Thermal transport is an important energy transfer process in nature. Phonon is the major energy carrier for heat in semiconductor and dielectric materials. In analogy to Ohm's law for electrical conductivity, Fourier's law is a fundamental rule of heat transfer in solids. It states that the thermal conductivity is independent of sample scale and geometry. Although Fourier's law has received great success in describing macroscopic thermal transport in the past two hundreds years, its validity in low dimensional systems is still an open question. Here we give a brief review of the recent developments in experimental, theoretical and numerical studies of heat transport in low dimensional systems, include lattice models, nanowires, nanotubes and graphenes. We will demonstrate that the phonon transports in low dimensional systems super-diffusively, which leads to a size dependent thermal conductivity. In other words, Fourier's law is breakdown in low dimensional structures

Gamma hydroxybutyrate (GHB), gamma butyrolactone (GBL) and 1,4 butanediol (1,4-BD; BDO) : a literature review with a focus on UK fatalities related to non-medical use

Misuse of gamma hydroxybutrate (GHB) and gamma butyrolactone (GBL) has increased greatly since the early 1990s, being implicated in a rising number of deaths. This paper reviews knowledge on GHB and derivatives, and explores the largest series of deaths associated with their non-medical use. Descriptive analyses of cases associated with GHB/GBL and 1,4 butanediol (1,4-BD) use extracted from the UK’s National Programme on Substance Abuse Deaths database. From 1995 to September 2013, 159 GHB/GBL-associated fatalities were reported. Typical victims: White (92%), young (mean age 32 years); male (82%); with a drug misuse history (70%). Most deaths (79%) were accidental or related to drug use, the remainder (potential) suicides. GHB/GBL alone was implicated in 37%; alcohol 14%; other drugs 28%; other drugs and alcohol 15%. Its endogenous nature and rapid elimination limit toxicological detection. Post-mortem blood levels: mean 482 (range 0 - 6500; S.D. 758) mg/L. Results suggest significant caution is needed when ingesting GHB/GBL, particularly with alcohol, benzodiazepines, opiates, stimulants, and ketamine. More awareness is needed about risks associated with consumption.Peer reviewe

Neural Mechanisms of Impaired Micturition Reflex in Rats with Acute Partial Bladder Outlet Obstruction

To determine the contribution of neural elements to micturition, we evaluated, in intact rats, the cystometrogram, pelvic afferent nervous activity, pelvic efferent nervous activity and external urethral sphincter - electromyogram activity in the normal and acute partial bladder outlet obstruction states. In the normal state, in response to saline filling, mechanoreceptor-dependent pelvic afferent nervous activity gradually activated and finally triggered a voiding reflex, including four phases of detrusor contractions. Phase 1 was characterized by an initial rising intravesical pressure, Phase 2 was characterized by a series of high- frequency oscillations in intravesical pressure, Phase 3 contraction was characterized by a rebound intravesical pressure and Phase 4 contraction was characterized by a rapid fall in intravesical pressure. In the acute partial bladder outlet obstruction state, Phase 1 contraction rose and high-frequency oscillations fell in Phase 2. This voiding dysfunction is ascribed to the bursting extraurethral sphincter activity being converted to tonic extraurethral sphincter activity. In summary, the suppressed high -frequency oscillations in Phase 2 of the detrusor muscle contraction could be detrimental to efficient voidings in the acute partial bladder outlet obstructed rat. (C) 2000 IBRO. Published by Elsevier Science Ltd

Classifier modeling and numerical taxonomy of Actinidia (Actinidiaceae) in Taiwan

Although kiwifruit (Actinidia) is popular worldwide, its complex morphology has resulted in long-standing confusion regarding its nomenclature, classification, and identification. In an attempt to resolve this issue, we conducted a phylogenetic analysis on 72 wild Actinidia accessions in Taiwan. We used 60 morphological characters as taxonomic traits to construct a seriated heat map that revealed A. callosa var. ephippioidea and A. rufa (sensu Flora of Taiwan, 2(nd) Edition) as introgressive hybrids between A. chinensis var. setosa and A. callosa (sensu Flora of Taiwan, 2(nd) Edition), as well as five significant groups of Actinida in Taiwan. Based on these results, we coded the indicator response matrix for the logistic regression models as dichotomizers and used a Bayesian discriminant model as a polychotomizer. After classifier modeling, the two classifiers were combined to identify Actinidia specimens in domestic and international herbaria. As a result, a taxonomic revision was made: A. callosa var. callosa and A. callosa var. ephippioidea were revised as A. rufa; A. rubricaulis was revised as A. callosa var. discolor; A. chinensis var. setosa was elevated to A. setosa; and A. tetramera was a misidentification of A. arguta. Of these, only A. setosa is endemic to Taiwan

Optical Cellular Micromotion: A New Paradigm to Measure Tumor Cells Invasion within Gels Mimicking the 3D Tumor Environments

Published online: June 28, 2022Measuring tumor cell invasiveness through 3D tissues, particularly at the single-cell level, can provide important mechanistic understanding and assist in identifying therapeutic targets of tumor invasion. However, current experimental approaches, including standard in vitro invasion assays, have limited physiolog-ical relevance and offer insufficient insight into the vast heterogeneity in tumor cell migration through tissues. To address these issues, here the concept of optical cellular micromotion is reported on, where digital holographic microscopy is used to map the optical nano- to submicrometer thickness fluctuations within single-cells. These fluctuations are driven by the dynamic movement of subcel-lular structures including the cytoskeleton and inherently associated with the biological processes involved in cell invasion within tissues. It is experimentally demonstrated that the optical cellular micromotion correlates with tumor cells motility and invasiveness both at the population and single-cell levels. In addi-tion, the optical cellular micromotion significantly reduced upon treatment with migrastatic drugs that inhibit tumor cell invasion. These results demonstrate that micromotion measurements can rapidly and non-invasively determine the inva-sive behavior of single tumor cells within tissues, yielding a new and powerful tool to assess the efficacy of approaches targeting tumor cell invasiveness.Zhaobin Guo, Chih-Tsung Yang, Chia-Chi Chien, Luke A. Selth, Pierre O. Bagnaninchi, and Benjamin Thierr

New highly nucleophilic and practically accessible chlorocarbenoids for carbonyl olefination

Direct oxidative addition of CHCl3 to the Mg-TiCl4 bimetallic species resulted in the generation of a highly nucleophilic and practically convenient chloromethylenetitanium complex, which efficiently effected condensation even with enolizable or inert carbonyl compounds, such as sterically congested ketones, to provide vinyl chloride compounds