Endothelial function and weight loss: Comparison of low‐carbohydrate and low‐fat diets

Objective: The effect of weight loss on obesity‐associated endothelial dysfunction is not clear because of conflicting data, demonstrating both improvement and no change in endothelial function after weight loss in obese subjects. A 2‐year prospective study (n = 121) was conducted to examine: (1) the effect of obesity and weight loss (either a low‐carbohydrate or and low‐fat diet) on flow mediated vasodilatation (FMD), a measure of endothelial function. Design and Methods: Participants reduced body weight by 7.1% ± 4.4%, 8.7% ± 6.8%, 7.1% ± 7.8%, and 4.1% ± 7.7% at 3, 6, 12, and 24 months, respectively with no significant differences between the low‐fat and low‐carbohydrate groups. Results: Endothelial function was inversely correlated with waist circumference, triglyceride level, and directly correlated with leptin in obese persons prior to weight loss. These weight losses did not confer any improvements in FMD. There were no differences between the low‐fat and low‐carbohydrate diets in FMD at any time point. At 6 months (r = 0.26, P = 0.04) and 1 year (r =0.28, P = 0.03), there were positive correlations between change in FMD and change in leptin but not at 2 years. Conclusion: There was no significant improvement in endothelial function after 7.1% ± 7.8% weight loss at 1 year and 4.1% ± 7.7% at 2 years, achieved by either a low carbohydrate or a low fat diet.     

Characterization of Bacillus subtilis spore inactivation in low‐pressure,low‐temperature gas plasma sterilization processes

Aims: To identify structural components of Bacillus subtilis spores serving as targets for sterilization with microwave induced low‐pressure, low‐temperature nitrogen‐oxygen plasma. Methods and Results: The inactivation of spores followed a biphasic kinetics consisting of a log‐linear phase with rapid inactivation followed by a slow inactivation phase. In the course of plasma treatment, damage to DNA, proteins and spore membranes were observed by monitoring the occurrence of auxotrophic mutants, inactivation of catalase (KatX) activity and the leakage of dipicolinic acid, respectively. Spores of the wild‐type strain showed the highest resistance to plasma treatment. Spores of mutants defective in nucleotide excision repair (uvrA) and small acid‐soluble proteins (ΔsspA ΔsspB) were more sensitive than those defective in the coat protein CotE or spore photoproduct repair (splB). Exclusion of reactive particles and spectral fractions of UV radiation from access to the spores revealed that UV‐C radiation is the most effective inactivation agent in the plasma, whereby the splB and ΔcotE mutant spores were equally and slightly less sensitive, respectively, than the wild‐type spores. Finally, the extent of damages in the spore DNA determined by quantitative PCR correlated with the spore inactivation. Conclusions: Spore inactivation was efficiently mediated by a combination of DNA damage and protein inactivation. DNA was identified to be the primary target for spore inactivation by UV radiation emitted by the plasma. Coat proteins were found to constitute a protective layer against the action of the plasma. Significance and Impact of the Study: The results provide new evidence to the understanding of plasma sterilization processes. This knowledge supports the identification of useful parameters for novel plasma sterilization equipment to control process safety.     

Mechanism of low‐temperature‐induced pollen failure in rice

Low‐temperature stress during microspore development alters cellular organization in rice anthers. The major cellular damage includes unusual starch accumulation in the plastids of the endothecium in postmeiotic anthers, abnormal vacuolation and hypertrophy of the tapetum, premature callose (1,3‐β‐glucan) breakdown and lack of normal pollen wall formation. These cellular lesions arise from damage to critical biochemical processes that include sugar metabolism in the anthers and its use by the microspores. Failure of utilization of the callose breakdown product and other microspore wall components like sporopollenin can also be considered as critical. In recent years, considerable progress has been made in the understanding of major biochemical processes including the expression of critical genes that are sensitive to low temperature in rice and cause male sterility. This paper combines a discussion of cellular organization and associated biochemical processes that are sensitive to low temperatures and provides an overview of the potential mechanisms of low‐temperature‐induced male sterility in rice.     

Recurrent adaptation in a low‐dispersal trait

The study of natural populations from contrasting environments has greatly enhanced our understanding of ecological‐dependent selection, adaptation and speciation. Cases of parallel evolution in particular have facilitated the study of the molecular and genetic basis of adaptive variation. This includes the type and number of genes underlying adaptive traits, as well as the extent to which these genes are exchanged among populations and contribute repeatedly to parallel evolution. Yet, surprisingly few studies provide a comprehensive view on the evolutionary history of adaptive traits from mutation to widespread adaptation. When did key mutations arise, how did they increase in frequency, and how did they spread? In this issue of Molecular Ecology, Van Belleghem et al. ( 2015 ) reconstruct the evolutionary history of a gene associated with wing size in the salt marsh beetle Pogonus chalceus. Screening the entire distribution range of this species, they found a single origin for the allele associated with the short‐winged ecotype. This allele seemingly evolved in an isolated population and rapidly introgressed into other populations. These findings suggest that the adaptive genetic variation found in sympatric short‐ and long‐winged populations has an allopatric origin, confirming that allopatric phases may be important at early stages of speciation.     

High‐ and low‐frequency mechanical properties of living starfish oocytes

We studied the mechanical properties of living starfish oocytes belonging to two species, Astropecten Auranciacus and Asterina pectinifera, over a wide range of timescales. We monitored the Brownian motion of microspheres injected in the cytoplasm using laser particle‐tracking (LPT) and video multiple‐particle‐tracking (MPT) techniques, to explore high‐ and low‐frequency response ranges, respectively. The analysis of the mean‐square‐displacements (MSD) allowed us to characterize the samples on different timescales. The MSD behavior is explained by three power‐law exponents: for short times (τ < 1 ms) it reflects the semiflexible behavior of the actin network; for intermediate timescales (1 ms < τ < 1 s) it is similar to that of a soft‐glass material; finally for long times (τ > 1 s) it behaves mainly like a viscous medium. We computed and compared the viscoelastic moduli using a recently proposed model describing the frequency response of the cell material. The large fluctuations found in the MSD over hundreds of trajectories indicate and confirm the significant cytoplasm heterogeneity. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Rebuilding coral reefs: success (and failure) 16 years after low‐cost,low‐tech restoration

Calls for coral reef restoration are increasing amidst continued declines, yet we know little about long‐term outcomes and conditions that lead to successful coral recovery. Here, we report on one of the longest monitoring studies following 16 years of large‐scale, “low‐tech” experimental reef rehabilitation on rubble fields created by chronic blast fishing in Komodo National Park, Indonesia. After blast fishing had stopped, in the absence of rehabilitation, hard coral cover in rubble fields remained about 3% from 1999 to 2016, but on rehabilitation treatments, cover increased from 0% in 2002 to 44.5% (±21.9% SD) in 2016. Coral cover varied among sites and treatments (ranging from <5 to >80% in 2016) in patterns that may reflect current strength and turbidity. Our results demonstrate that low‐tech substrate stabilization can facilitate natural coral recruitment and growth. We conclude that relatively low‐cost methods can deliver sustained rehabilitation of hard coral cover and that long‐term monitoring should be incorporated more widely in restoration activities to inform return on investment.     

Psychotherapies for depression in low‐ and middle‐income countries: a meta‐analysis

Most psychotherapies for depression have been developed in high‐income Western countries of North America, Europe and Australia. A growing number of randomized trials have examined the effects of these treatments in non‐Western countries. We conducted a meta‐analysis of these studies to examine whether these psychotherapies are effective and to compare their effects between studies from Western and non‐Western countries. We conducted systematic searches in bibliographical databases and included 253 randomized controlled trials, of which 32 were conducted in non‐Western countries. The effects of psychotherapies in non‐Western countries were large (g=1.10; 95% CI: 0.91‐1.30), with high heterogeneity (I²=90; 95% CI: 87‐92). After adjustment for publication bias, the effect size dropped to g=0.73 (95% CI: 0.51‐0.96). Subgroup analyses did not indicate that adaptation to the local situation was associated with the effect size. Comparisons with the studies in Western countries showed that the effects of the therapies were significantly larger in non‐Western countries, also after adjusting for characteristics of the participants, the treatments and the studies. These larger effect sizes in non‐Western countries may reflect true differences indicating that therapies are indeed more effective; or may be explained by the care‐as‐usual control conditions in non‐Western countries, often indicating that no care was available; or may be the result of the relative low quality of many trials in the field. This study suggests that psychotherapies that were developed in Western countries may or may not be more effective in non‐Western countries, but they are probably no less effective and can therefore also be used in these latter countries.     

Modified low‐salt CTAB extraction of high‐quality DNA from contaminant‐rich tissues

The increasing use of high‐throughput sequencing platforms has made the isolation of pure, high molecular weight DNA a primary concern for studies of a diverse range of organisms. Purification of DNA remains a significant challenge in many tissue and sample types due to various organic and inorganic molecules that coprecipitate with nucleic acids. Molluscs, for example, contain high concentrations of polysaccharides which often coprecipitate with DNA and can inhibit downstream enzymatic reactions. We modified a low‐salt CTAB (MoLSC) extraction protocol to accommodate contaminant‐rich animal tissues and compared this method to a standard CTAB extraction protocol and two commercially available animal tissue DNA extraction kits using oyster adductor muscle. Comparisons of purity and molecular integrity showed that our in‐house protocol yielded genomic DNA generally free of contaminants and shearing, whereas the traditional CTAB method and some of the commercial kits yielded DNA unsuitable for some applications of massively parallel sequencing. Our open‐source MoLSC protocol provides a cost‐effective, scalable, alternative DNA extraction method that can be easily optimized and adapted for sequencing applications in other contaminant‐rich samples.     

The Ku‐dependent non‐homologous end‐joining pathway contributes to low‐dose radiation‐stimulated cell survival

Low‐dose (≤0.1 Gy) radiation‐induced adaptive responses could protect cells from high‐challenge dose radiation‐induced killing. The protective role is believed to promote the repair of DNA double‐strand breaks (DSBs) that are a severe threat to cell survival. However, it remains unclear which repair pathway, homologous recombination repair (HRR) or non‐homologous end‐joining (NHEJ), is promoted by low‐dose radiation. To address this question, we examined the effects of low‐dose (0.1 Gy) on high‐challenge dose (2–4 Gy) induced killing in NHEJ‐ or HRR‐deficient cell lines. We showed that 0.1 Gy reduced the high‐dose radiation‐induced killing for wild‐type or HRR‐deficient cells, but enhanced the killing for NHEJ‐deficient cells. Interestingly, low‐dose radiation also enhanced the killing for wild‐type cells exposed to high‐challenge dose radiation with high‐linear energy transfer (LET). Because it is known that high‐LET radiation induces an inefficient NHEJ, these results support that the low‐dose radiation‐stimulated protective role in reducing high‐challenge dose (low‐LET)‐induced cell killing might depend on NHEJ. In addition, we showed that low‐dose radiation activated the DNA‐PK catalytic subunit (DNA‐PKcs) and the inhibitor of DNA‐PKcs destroyed the low‐dose radiation‐induced protective role. These results suggest that low‐dose radiation might promote NHEJ through the stimulation of DNA‐PKcs activity and; therefore, increase the resistance of cells to high‐challenge dose radiation‐induced killing. J. Cell. Physiol. 226: 369–374, 2011. © 2010 Wiley‐Liss, Inc.     

Modulation of immune response to induced‐arthritis by low‐level laser therapy

As low‐level laser therapy immune cells responses are not always clarified, this study aimed to evaluate cytokines and immune cells profile after low‐level laser therapy (LLLT) on arthritis‐induced model. Arthritis was induced in C57BL/6 mice divided into five groups: euthanized 5 hours after inflammation induction; untreated; dexamethasone treated; LLLT at 3 Jcm^?2; LLLT at 30 Jcm^?2. Cytokine measurements by enzyme‐linked immunosorbent assay and mRNA cytokine relative levels by real‐time quantitative polymerase chain reaction were performed with arthritic ankle (IL‐1β, IL‐6, TNF‐α, IL‐10 and TGF‐β). Macrophages, dendritic cells, natural killer cells, lymphocytes CD4⁺, CD8⁺, Treg and costimulatory proteins were quantified in proximal lymph node by flow cytometry. Data showed decrease in all cytokine levels after LLLT and alteration in mRNA relative levels, depending on the energy density used. LLLT was able to increase of immune cell populations analyzed in the lymph node as well as costimulatory proteins expression on macrophages and dendritic cells. Treg TCD4⁺ and TCD8⁺ population enrichment were observed in LLLT at 3 and 30 Jcm^?2 groups, respectively. Furthermore, Treg TCD8⁺ cells expressing higher levels of CD25 were observed at LLLT at 30 Jcm^?2 group. Our results indicate that LLLT could change the inflammatory course of arthritis, tending to accelerate its resolution through immune cells photobiostimulation.      

A low‐cost,computer‐controlled robotic flower system for behavioral experiments

Human observations during behavioral studies are expensive, time‐consuming, and error prone. For this reason, automatization of experiments is highly desirable, as it reduces the risk of human errors and workload. The robotic system we developed is simple and cheap to build and handles feeding and data collection automatically. The system was built using mostly off‐the‐shelf components and has a novel feeding mechanism that uses servos to perform refill operations. We used the robotic system in two separate behavioral studies with bumblebees (Bombus terrestris): The system was used both for training of the bees and for the experimental data collection. The robotic system was reliable, with no flight in our studies failing due to a technical malfunction. The data recorded were easy to apply for further analysis. The software and the hardware design are open source. The development of cheap open‐source prototyping platforms during the recent years has opened up many possibilities in designing of experiments. Automatization not only reduces workload, but also potentially allows experimental designs never done before, such as dynamic experiments, where the system responds to, for example, learning of the animal. We present a complete system with hardware and software, and it can be used as such in various experiments requiring feeders and collection of visitation data. Use of the system is not limited to any particular experimental setup or even species.     

Perturbation‐independent community development in low‐temperature anaerobic biological wastewater treatment bioreactors

The reproducibility and stability of low‐ temperature anaerobic wastewater treatment systems undergoing transient perturbations was investigated. Three identical anaerobic expanded granular sludge bed‐based bioreactors were used to degrade a volatile fatty acid and glucose‐based wastewater under sub‐ambient (15°C) conditions. The effect of a variety of environmental perturbations on bioreactor performance was assessed by chemical oxygen demand removal. Temporal microbial community development was monitored by denaturation gradient gel electrophoresis (DGGE) of 16S rRNA genes extracted from sludge granules. Methanogenic activity was monitored using specific methanogenic activity assays. Bioreactor performance and microbial population dynamics were each well replicated between both experimental bioreactors and the control bioreactor prior to, and after the implementation of most of the applied perturbations. Gene fingerprinting data indicated that Methanosaeta sp. were the persistent, keystone members of the archaeal community, and likely were pivotal for the physical stability and maintenance of the granular biofilms. Cluster analyses of DGGE data suggested that temporal shifts in microbial community structure were predominantly independent of the applied perturbations. Biotechnol. Bioeng. 2010;105: 79–87. © 2009 Wiley Periodicals, Inc.     

Exposure of low‐concentration arsenic‐initiated inflammation and autophagy in rat lungs

Chronic arsenic exposure through water intake is a worldwide issue, which has caused many diseases. Lungs are the first target organ of arsenic and lung inflammation, autophagy, and even the onset of tumors can be induced by arsenic exposure. Here, we tested the outcome of low‐concentration arsenic exposure in rat lungs. Tissue changes, inflammation, autophagy, and other physiological responses were observed in this study. Results showed that low‐concentration exposure of arsenite through water intake could initiate autophagy and inflammation in lungs but high concentration exposure produced a weak autophagy response and accentuated inflammation with the possibility of a chronic inflammation environment emerging followed by tumorigenesis.