Natural Decay Research Articles

Layer analysis of CO2 sources in the US economic supply chains: an input output LCA study

Purpose Carbon footprint assessment requires a holistic approach, where all possible lifecycle stages of products from raw material extraction to the end of life are considered. The purpose of this paper is to develop an analytical sustainability assessment framework to assess the carbon footprint of US economic supply chains from two perspectives: supply chain layers (tiers) and carbon footprint sources. Design/methodology/approach The methodology consists of two phases. In the first phase, the data were collected from EORA input output and environmental impact assessment database. In the second phase, 48 input-output-based lifecycle assessment models were developed (seven CO2 sources and total CO2 impact, and six supply chain tiers). In the third phase, the results are analyzed by using data visualization, data analytics, and statistical approaches in order to identify the heavy carbon emitter industries and their percentage shares in the supply chains by each layer and the CO2 source. Findings Vast majority of carbon footprint was found to be attributed to the power generation, petroleum refineries, used and secondhand goods, natural gas distribution, scrap, and truck transportation. These industries dominated the entire supply chain structure and found to be the top drivers in all six layers. Practical implications This study decomposes the sources of the total carbon footprint of US economic supply chains into six layers and assesses the percentage contribution of each sector in each layer. Thus, it paves the way for quantifying the carbon footprint of each layer in today’s complex supply chain structure and highlights the importance of handling CO2 source in each layer separately while maintaining a holistic focus on the overall carbon footprint impacts in the big picture. In practice, one size fits all type of policy making may not be as effective as it could be expected. Originality/value This paper provides a two-dimensional viewpoint for tracing/analyzing carbon footprint across a national economy. In the first dimension, the national economic system is divided into six layers. In the second dimension, carbon footprint analysis is performed considering specific CO2 sources, including energy production, solvent, cement and minerals, agricultural burning, natural decay, and waste. Thus, this paper contributes to the state-of-art sustainability assessment by providing a comprehensive overview of CO2 sources in the US economic supply chains.

Watching the emergence of a Fano resonance in doubly excited helium

SynopsisWe report on the experimental observation of the buildup of the 2s2p Fano resonance in helium in the time domain, which has been under theoretical investigation for more than a decade. The emergence of the absorption line is temporally resolved by interrupting the natural decay of the excited state via saturated strong-field ionization at a variable time delay. We compare the experimental data with full ab-initio simulations to validate the time-gating by strong-field ionization and thereby confirm the recently developed theory for the formation of Fano line-profiles.

EXPERIMENTAL TAPHONOMY OF KERATIN: A STRUCTURAL ANALYSIS OF EARLY TAPHONOMIC CHANGES

Research Article| October 10, 2017 EXPERIMENTAL TAPHONOMY OF KERATIN: A STRUCTURAL ANALYSIS OF EARLY TAPHONOMIC CHANGES EVAN T. SAITTA; EVAN T. SAITTA 1School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol, BS8 1RJ, UK Search for other works by this author on: GSW Google Scholar CHRISTOPHER S. ROGERS; CHRISTOPHER S. ROGERS 2School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Field, N Mall, Cork, T23 XA50, Ireland Search for other works by this author on: GSW Google Scholar RICHARD A. BROOKER; RICHARD A. BROOKER 1School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol, BS8 1RJ, UK Search for other works by this author on: GSW Google Scholar JAKOB VINTHER JAKOB VINTHER 1School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol, BS8 1RJ, UK 3School of Biological Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol, BS8 1TQ, UK Search for other works by this author on: GSW Google Scholar PALAIOS (2017) 32 (10): 647–657. https://doi.org/10.2110/palo.2017.051 Article history first online: 16 Oct 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Search Site Citation EVAN T. SAITTA, CHRISTOPHER S. ROGERS, RICHARD A. BROOKER, JAKOB VINTHER; EXPERIMENTAL TAPHONOMY OF KERATIN: A STRUCTURAL ANALYSIS OF EARLY TAPHONOMIC CHANGES. PALAIOS 2017;; 32 (10): 647–657. doi: https://doi.org/10.2110/palo.2017.051 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search nav search search input Search input auto suggest search filter All ContentBy SocietyPALAIOS Search Advanced Search Abstract: The evolution of integumentary structures, particularly in relation to feathers in dinosaurs, has become an area of intense research. Our understanding of the molecular evolution of keratin protein is greatly restricted by the fact that such information is lost during diagenesis and cannot be derived from fossils. In this study, decay and maturation experiments are used to determine if different keratin types or integumentary structures show different patterns of degradation early in their taphonomic histories and if such simulations might advance our understanding of different fossilization pathways. Although different distortion patterns were observed in different filamentous structures during moderate maturation and ultrastructural textures unique to certain types of scales persisted in moderate maturation, neither of these have been observed in fossils. It remains uncertain whether these degradation patterns would ever occur in natural sediment matrix, where microbial and chemical decay happens well before significant diagenesis. It takes some time for remains to be buried, meaning that keratin may not be left for moderate maturation to produce such patterns. Higher, more realistic maturation conditions produce a thick, and water soluble fluid that lacks all morphological and ultrastructural details of the original keratin, suggesting that such textural or distortion patterns are unlikely to be preserved in fossils. Although different degradation patterns among keratinous structures are intriguing, it is unlikely that such information could be recorded in the fossil record. Calcium phosphates and pigments are the surviving components of integumentary structures. Thus, the results here are likely of more relation to the archaeological record than fossil record. Other noteworthy results of these experiments are that melanin may not be the leading factor in determining the rate of microbial decay in feathers but may reduce the rate of degradation from maturation, that the existence of rachis filamentous subunits similar to plumulaceous barbules is supported, and that previously reported dinosaur ‵erythrocytes' may be taphonomic artifacts of degraded organic material. You do not currently have access to this article.

Pyrolysis characteristic changes of poplar wood during natural decay

To explore the pyrolysis characteristic changes of wood during natural decay, 4 different degrees of decay of poplar wood (PW) were chosen and pyrolysis behaviors were studied by TGA and Py-GC/MS. The results indicated that with an increase of decay degree from 0% to 60%, the contents of hemicellulose and cellulose decreased from 22.2 and 46.39wt.% to 11.77 and 22.32wt.%, and that of lignin and extractives increased from 23.9 and 6.60wt.% to 39.85 and 20.84wt.%, respectively. The pyrolysis processes mainly happened in two stages. Lower degrees of decay did not have much influence on the pyrolysis behaviors, but with an increase of the decay degree, the pyrolysis behaviors were much more similar to those of the milled wood lignin from PW. The changes of the physical and chemical structures resulted in the decrease of Activation Energy from 91.37 to 74.08kJ/mol. Meanwhile, in the bio-oil, the contents of the ketones, carbonyls, sugars and furans changed slightly from 15.67%, 4.61%, 8.31% and 7.86% to 12.52%, 3.32%, 7.90% and 6.46%, respectively. However, the content of the acids decreased from 19.03% to 11.25%, and that of phenols significantly increased from 22.52% to 35.97%. Therefore rotten wood could be used as the feedstock of the selective pyrolysis to product the phenols.

Hydrogen gas prolongs the shelf life of kiwifruit by decreasing ethylene biosynthesis

The application of hydrogen-rich water was recently shown to inhibit senescence process of kiwifruit, but it is unclear if hydrogen gas (H2) exerts a similar function. The present results show that the production of endogenous H2 in kiwifruit decreases during ripening. Fumigation with H2 not only increased endogenous H2 concentrations but delayed the softening and cell wall disassembly in flesh. Ethylene (C2H4) production was also inhibited by H2, which was supported by a decrease in 1-aminocyclopropene-1-carboxylate (ACC) concentration, ACC synthase, and ACC oxidase activities, and the downregulation of the corresponding gene transcripts. Further, ACC-induced C2H4 production and ripening were blocked by H2 and the incidence of natural decay and disease incidence were reduced. Overall, the results suggested that the H2-induced delay of kiwifruit ripening resulted from an inhibitory effect on C2H4 biosynthesis.

Protective role of epiphytic fluorescent Pseudomonas on natural postharvest decay of tomato at room temperature.

Following harvest, tomato fruits are susceptible to attack by many fungal pathogens, but healthy fruits may also harbor beneficial microflora, which can delayed the spoilage of fruit. In this study, 30 isolates of epiphytic fluorescent Pseudomonas were isolated from healthy fruits of lemon, melon, grapefruit, tomato and orange. Twelve isolates were identified on molecular basis by amplifying 16S rDNA using a genus-specific primer set PA-GS-F 5’-GACGGGTGAGTAATGCCTA-3’ and PA-GS-R F 5’-CACTGGTGTTCCTTCCTATA-3’ on a conserved sequence of the genus Pseudomonas with a product size ~618 bp. Three potential isolates were examined for their ability to delayed the postharvest natural spoilage and maintained the physiochemical properties during storage for fifteen days in season 2013 and 2014. All three isolates showed promising control of postharvest diseases of tomato in comparison with control in both seasons up to fifteen days of storage at room temperature (23±4 oC, Rh 25-70%). The epiphytic bacterial isolates has delayed the fruit weight loss and maintained fruit firmness, total solids, pH and titratable acidity. Isolates also slowed the accumulation of lycopene indicating their potential in controlling the major changes in physiochemical properties. In both season Pseudomonas treated tomatoes showed no or negligible infestation of common postharvest fungi and bacteria as compared to control and positive control (1% K-sorbate).

Single atoms coupled to a near-concentric cavity

Concentric cavities can lead to strong photon-atom coupling without a need for high finesse or small physical-cavity volume. In a proof-of-principle experiment of this concept we demonstrate coupling of single Rb atoms to a 11mm long near-concentric cavity with a finesse F=138(2). Operating the cavity 1.65(1)$\mu$m shorter than the critical length, we observe an atom-cavity coupling constant $g_0=2\pi \times 5.0(2)\,$MHz which exceeds the natural dipole decay rate $\gamma$ by a factor $g_0/\gamma=1.7(1)$.

Post flooding damage assessment of earth dams and historical reservoirs using non-invasive geophysical techniques

This paper describes the use of four geophysical techniques to map the structural integrity of historical earth reservoir embankments which are susceptible to natural decay with time.The four techniques that were used to assess the post flood damage were 1. A fast scanning technique using a dipole electromagnetic profile apparatus (GEM2), 2. Electrical Resistivity Tomography (ERT) in order to obtain a high resolution image of the shape of the damaged/seepage zone, 3. Self-Potential surveys were carried out to relate the detected seepage evolution and change of the water displacement inside the embankment, 4. The washed zone in the areas with piping was characterised with microgravimetry.The four geophysical techniques used were evaluated against the case studies of two reservoirs in South Bohemia, Czech Republic. A risk approach based on the Geophysical results was undertaken for the reservoir embankments. The four techniques together enabled a comprehensive non-invasive assessment whereby remedial action could be recommended where required. Conclusions were also drawn on the efficiency of the techniques to be applied for embankments with wood structures.

Conifer species influence Heterobasidion irregulare sporulation on stem discs exposed to natural inoculum and root wood decay in soil‐block tests

SummaryThe fungal pathogen Heterobasidion irregulare has caused substantial damage to pine species in much of the south‐eastern United States, but the potential for damage from Heterobasidion root disease to forest tree species of the Great Lakes Region has not been thoroughly investigated. In each of three trials in two infested stands, fresh stem discs of six native conifer species were exposed to natural inoculum and examined for the asexual Spiniger stage of H. irregulare after incubation in the laboratory. In the first trial, the fungus was infrequently observed on discs, and differences among species were not found. But in the other two trials, detection of the pathogen was much more frequent on discs of tamarack (Larix laricina), red pine (Pinus resinosa) and white spruce (Picea glauca) than those of northern white cedar (Thuja occidentalis), eastern hemlock (Tsuga canadensis) and balsam fir (Abies balsamea). In a second study, the ability of an isolate of H. irregulare to decay root sapwood of these same species was compared using a soil‐block decay test. After 16 weeks of incubation, weight loss due to decay was greatest for red pine (23.2%) and larch (19.1%) and least for balsam fir (1.3%). Differences in the ability of H. irregulare to infect and saprophytically utilize substrate of these important tree species should prompt additional investigation of the relative risk posed to forests of the Great Lakes Region.

Assessment of a monumental masonry bell-tower after 2016 Central Italy seismic sequence by long-term SHM

The response of the San Pietro monumental bell-tower located in Perugia, Italy, to the 2016 Central Italy seismic sequence is investigated, taking advantage of the availability of field data recorded by a vibration-based SHM system installed in December 2014 to detect earthquake-induced damages. The tower is located about 85 km in the NW direction from the epicenter of the first major shock of the sequence, the Accumoli Mw6.0 earthquake of August 24th, resulting in a small local PGA of about 30 cm/s2, whereby near-field PGA was measured as 915.97 cm/s2 (E–W component) and 445.59 cm/s2 (N–S component). Similar PGA values also characterized the two other major shocks of the sequence (Ussita Mw5.9 and Norcia Mw6.5 earthquakes of October 26th and 30th, respectively). Despite the relatively low intensity of such earthquakes in Perugia, the analysis of long-term monitoring data clearly highlights that small permanent changes in the structural behavior of the bell-tower have occurred after the earthquakes, with decreases in all identified natural frequencies. Such natural frequency decays are fully consistent with what predicted by non-linear finite element simulations and, in particular, with the development of microcracks at the base of the columns of the belfry. Microcracks in these regions, and in the rest of tower, are however hardly distinguishable from pre-existing ones and from the physiological cracking of a masonry structure, what validates the effectiveness of the SHM system in detecting earthquake-induced damage at a stage where this is not yet detectable by visual inspections.

Numerical simulation of Post Accident Heat Removal in a typical pool-type SFR under severe core relocation scenario

Under a hypothetical core meltdown and relocation scenario in Sodium cooled Fast Reactor (SFR), there may be a chance for reactor main vessel failure if the core debris are allowed to settle at the bottom of this vessel. To avoid this, an in-vessel core catcher assembly is installed in pool type SFRs just above the bottom wall of the main vessel. The function of this assembly is to collect, retain and passively cool the core debris by assisting natural convection decay heat removal from these debris. In this work, the passive decay heat removal from the core debris settled on single-tray-type design of core catcher has been numerically simulated under different amounts of core relocation using a validated 2-D axisymmetric CFD model. The maximum temperature experienced by the debris bed, core catcher plate and the welded joint between the core support structure and the main vessel (i.e., triple point) are evaluated in order to estimate the amount of core relocation that can be safely handled by the primary containment system under Post Accident Heat Removal (PAHR) scenario. The numerical study revealed that the single-tray-type design of core catcher can potentially assist the passive cooling even under the settling of debris material with heat generation equivalent to 60% of the full core on the core catcher. In addition to this, the effect of the size of opening created on grid plate during core relocation on Post Accident Heat Removal (PAHR) is studied for different amounts of core relocation. From this numerical study, the thermal capability of single-tray type in-vessel core catcher of SFR is assessed. The predictions are useful in determining the safe thermal margins available under core relocation scenarios and extending the functionality of single-tray-type core catcher for handling Whole Core Meltdown Accident (WCA) scenario in future SFRs.

70% Ethanol for Decontamination of Central Venous Lines Exposed to Calcineurin Inhibitors.

Tacrolimus, commonly used for graft versus host disease prophylaxis is usually administered via a dedicated central venous line (CVL) and trough levels drawn from the unexposed lumen. Being an oil-based medication, it may be adsorbed to the inner lumen of the CVL and result in falsely high levels drawn from an inadvertently exposed lumen. There is no treatment for decontamination of such CVLs, and natural decay occurs over months before the CVL can be used to draw reliable trough levels. The primary objective of the study was to estimate the effectiveness of 70% ethanol locks for decontaminating CVLs exposed to tacrolimus. We studied the efficacy of 70% ethanol lock in decontaminating CVLs exposed to tacrolimus in patients during transplant. Trough tacrolimus levels were drawn from the exposed and unexposed (control) lumens at 8:00 am, followed by a 2-mL 70% ethanol lock instilled for a 2-hour dwell into the exposed (intervention) lumen. Trough tacrolimus levels were again drawn from both lumens at 8:00 pm and levels compared for efficacy. All 20 sets showed a high 8 am trough level in the exposed intervention arm (median = 30 ng/mL), significantly greater ( P < 0.0001) than that in the control arm (median = 9.05 ng/mL), and were contaminated. After the 2-hour ethanol lock, 65% of the lumens were decontaminated. The difference between the control and intervention arms was no longer found to be statistically significant ( P = 0.0826). A 2-hour 70% ethanol lock is effective for decontamination of CVLs exposed to tacrolimus.

How miRs and mRNA deadenylases could post-transcriptionally regulate expression of tumor-promoting protein PLD.

Phospholipase D (PLD) plays a key role in both cell membrane lipid reorganization and architecture, as well as a cell signaling protein via the product of its enzymatic reaction, phosphatidic acid (PA). PLD is involved in promoting breast cancer cell growth, proliferation, and metastasis and both gene and protein expression are upregulated in breast carcinoma human samples. In spite of all this, the ultimate reason as to why PLD expression is high in cancer cells vs. their normal counterparts remains largely unknown. Until we understand this and the associated signaling pathways, it will be difficult to establish PLD as a bona fide target to explore new potential cancer therapeutic approaches. Recently, our lab has identified several molecular mechanisms by which PLD expression is high in breast cancer cells and they all involve post-transcriptional control of its mRNA. First, PA, a mitogen, functions as a protein and mRNA stabilizer that counteracts natural decay and degradation. Second, there is a repertoire of microRNAs (miRs) that keep PLD mRNA translation at low levels in normal cells, but their effects change with starvation and during endothelial-to-mesenchymal transition (EMT) in cancer cells. Third, there is a novel way of post-transcriptional regulation of PLD involving 3'-exonucleases, specifically the deadenylase, Poly(A)-specific Ribonuclease (PARN), which tags mRNA for mRNA for degradation. This would enable PLD accumulation and ultimately breast cancer cell growth. We review in depth the emerging field of post-transcriptional regulation of PLD, which is only recently beginning to be understood. Since, surprisingly, so little is known about post-transcriptional regulation of PLD and related phospholipases (PLC or PLA), this new knowledge could help our understanding of how post-transcriptional deregulation of a lipid enzyme expression impacts tumor growth.

Life-span of in vitro differentiated Plasmodium falciparum gametocytes

BackgroundThe sexual stages (gametocytes) of Plasmodium falciparum do not directly contribute to the pathology of malaria but are essential for transmission of the parasite from the human host to the mosquito. Mature gametocytes circulate in infected human blood for several days and their circulation time has been modelled mathematically from data of previous in vivo studies. This is the first time that longevity of gametocytes is studied experimentally in vitro.MethodsThe in vitro longevity of P. falciparum gametocytes of 1 clinical isolate and 2 laboratory strains was assessed by three different methods: microscopy, flow cytometry and reverse transcription quantitative real-time PCR (RT-qPCR). Additionally, the rate of gametocytogenesis of the used P. falciparum strains was compared.ResultsThe maximum in vitro lifespan of P. falciparum gametocytes reached almost 2 months (49 days by flow cytometry, 46 days by microscopy, and at least 52 days by RT-qPCR) from the starting day of gametocyte culture to death of last parasite in the tested strains with an average 50% survival rate of 6.5, 2.6 and 3.5 days, respectively. Peak gametocytaemia was observed on average 19 days after initiation of gametocyte culture followed by a steady decline due to natural decay of the parasites. The rate of gametocytogenesis was highest in the NF54 strain.ConclusionsPlasmodium falciparum mature gametocytes can survive up to 16–32 days (at least 14 days for mature male gametocytes) in vitro in absence of the influence of host factors. This confirms experimentally a previous modelling estimate that used molecular tools for gametocyte detection in treated patients. The survival time might reflect the time the parasite can be transmitted to the mosquito after clearance of asexual parasites. These results underline the importance of efficient transmission blocking agents in the fight against malaria.

Internal contamination of the Cs[formula omitted]HfCl[formula omitted] crystal scintillator

The internal contamination (radio-purity) of a cesium hafnium chloride (Cs2HfCl6) crystal scintillator and its starting material (CsCl, HfCl4 initial and after 3-fold static sublimation purification) was studied by HR-ICP-MS and with an ultra-low-background high purity germanium (ULB-HPGe) detector deep underground. This study was conducted for the purpose of assessing the feasibility of using CHC as a potential detector to the search for rare α decay occurring in Hafnium isotopes. Despite the low radio-purity of starting material, the resulting analysis concluded that the grown CHC crystal is free of nuclides of the U/Th natural decay chain. Only a limit was set on their activities to a few mBq/kg. However, the crystal was found to contain artificial and cosmogenic radionuclides: 137Cs at 0.8 Bq/kg, 132Cs at 25 mBq/kg, 134Cs at 52 mBq/kg and 181Hf at 14 mBq/kg.

Variation of Chemical Constituents of Qinghai Spruce in Natural Decay Process, Including Furfural Production

Chemical constituents of naturally decayed Qinghai spruce branches were analyzed in terms of holocellulose, lignin, and pentosan. The holocellulose content declined from 57.98% to 35.29% in one year. The rate of change may be related to weather conditions, i.e., the rate of variation was higher when the temperature was high and rainfall was abundant. The changes in lignin and pentosan relative content were completely different from holocellulose; they increased first and then decreased during the decay period. Compared with fresh raw materials, pentosan content (from 14.44% to 25.9%) was increased by 79.4% after four months decay. The highest yield of furfural (10.2%) prepared by a two-stage method from decayed Qinghai spruce branches was similar to the reported yield from corncobs.

Mechanical Transient Characteristics Analysis of the Drive Train of Wind Turbine

In order to meet the assessment need for the control of the drive train resonance of wind turbine and the drive shaft torque during grid voltage dips, the research of mechanical transient characteristics of the drive train at a voltage drop was proposed. Firstly, the state equation of twomass model was established based on the drive train models. Secondly, based on the physical expression of the natural frequency and mechanical decay time constant of the drive train, the influence of transmission parameters on the natural frequency and decay time and the shaft torque was analyzed. Then, the drive shaft torque characteristics were also investigated in the condition of voltage drop. Finally, as an example of the factual parameters of the drive train, the simulation model of transmission system was established by MATLAB/Simulink to simulate the mechanical transient characteristics. The validity of analytic expression was confirmed through the simulation results.

Georg Trakl's Ghosts: Haunted Poems at the End of History

Georg Trakl has been described by Bernhard Böschenstein as a “poet of post‐history.” In his rich but enigmatic poems, the perspective is imagined near the end‐point of the arc of history, where the speaker observes signs of advancing natural and cultural decay. One characteristic of Trakl's historical end stage is the encroachment of the supernatural sphere upon the natural, as boundaries are loosened between past and present, life and death, real and spectral. A clear development can be detected in Trakl's treatment of the supernatural theme. The earlier poems have naturalistic settings whose familiarity is progressively undermined by ghostly apparitions. In the later ones, the supernatural element becomes more pervasive, as historical and mythical relations become manifest spatially and climactic events from the speaker's life history and cultural tradition are re‐enacted in abject form. This essay plots the historical and supernatural themes through Trakl's work via discussion of specific poems.

Assesment of the response of the meteorological/hydrological parameters on the soil gas radon emission at Hsinchu, northern Taiwan: A prerequisite to identify earthquake precursors

The present study is an attempt to assess and quantify the influence of the meteorological (atmospheric temperature and pressure) and hydrological (rainfall and ground water head-GWH) parameters on the soil gas radon emission at Hsinchu, northern Taiwan. The quasi-periodic variations corresponding to diurnal and semi diurnal periods were estimated and eliminated by decomposing the time series for the period of September 16, 2009 to March 5, 2010 to singular spectrum analysis. The reconstructed non-periodic variations, which reproduce the salient feature of recorded time series, were searched for meteorological/hydrological influences in radon emission. The combined response of barometric pressure and atmosphere temperature are found to be small when compared to the total variability in radon. The influence of rainfall on radon is found to be strongest. At the onset of rainfall, radon shows a step-jump that attains peak with a time lag of 12–15h. This enhancement is attributed to entrapment of soil gas in the top soil cover as increased soil moisture prevents escape of radon into the atmosphere (capping effect). The decay of radon after the recession of rainfall is approximated by double exponential decay terms, one corresponding to the natural decay of radon with half life of 3.84days and second representing slow weakening of capping effect. The third effect related to internal loading due to rise and fall of groundwater modulates the propagation of radon in overlying strata, accounting for the long term variations in radon. The rainfall inflicted changes in radon look strikingly similar to earthquake related precursory or co-seismic perturbations, inferred by long term synotopic observations. It is surmised that unless radon variations are corrected for meteorological/hydrological contamination, some precursory signals are masked on one hand while on the other hand some anomalies are falsely viewed as earthquake precursors.

The biocontrol effect of Sporidiobolus pararoseus Y16 against postharvest diseases in table grapes caused by Aspergillus niger and the possible mechanisms involved

Fruits are vulnerable to pathogen infection caused by decay during growth and storage, which causes huge economic losses. The aim of this study was to investigate the biocontrol efficacy of the antagonistic yeast Sporidiobolus pararoseus Y16 in the control of Aspergillus niger decay, and natural decay of table grapes and the possible mechanisms involved. The results showed that S. pararoseus Y16 at different concentrations significantly inhibited A. niger decay of table grapes compared with the control. Besides, the population dynamics results showed that S. pararoseus Y16 could rapidly survive and proliferate in grape wounds or on grape surfaces at 20°C. Moreover, S. pararoseus Y16 treatment did not impair postharvest qualities of table grapes. Results also showed that treatment with S. pararoseus Y16 enhanced the enzyme activities of polyphenol oxidase (PPO), catalase (CAT), phenylalanine ammonia-lyase (PAL) and ascorbate peroxidase (APX) in table grapes. Furthermore, the gene expression levels of PPO, CAT, PAL and APX were increased by gene level verification. All these results indicated that S. pararoseus Y16 has great potential for development of commercial formulations to control postharvest pathogens on table grapes. These findings revealed that the enhanced gene expression and enzyme activities are the mechanisms involved in the biocontrol, while the yeast outcompeted the fungus for space and nutrients.