185 research outputs found
Characterization of Larval Lepidopteran Gut Stem Cell Markers
The larval lepidopteran midgut is a complex tissue system that shows significant structure-function relationships related to its roles in digestive and absorptive processes. δ-endotoxins (Cry toxins) produced by the bacterium Bacillus thuringiensis disrupt the midgut epithelium of target insects has been used extensively to control pests. However, insects, including several lepidopteran species, evolve resistance to Cry toxins which causes a great threat to their continued utility. Understanding the physiology of the midgut, including that of the stem cells which are responsible for midgut growth, development, and regeneration, may improve the sustainability of midgut-targeted control like Cry toxins. Historically, lepidopteran midgut stem cells have been distinguished from mature cells by morphology, but this is unreliable due to significant morphological variation in both mature and stem populations, including during the differentiation processes of the latter. Thus, we examined three vital markers to distinguish larval lepidopteran midgut stem and mature cell types, as well as the differentiation state of stem cells using esterase activity (Calcein AM), mitochondrial density (Mitotracker), and mitochondrial membrane potential (TMRM). We also identified the existence and the expression level of one stemness maintainer gene Escargot among different development stages of lepidopteran larvae. Our results support the use of mitochondrial properties in lepidopteran midgut cell differentiation and indicate esterase activity is an insufficient marker even combined with morphology. Further, escargot transcript patterns support further examination of the role of the protein in gut physiology, including stem maintenance. Our results provide tools for characterization and modification of physiological responses of lepidopteran midgut cells to stimuli and stresses. These in turn will aid in understanding conservation and divergence of developmental processes and development and use of pest control resources
Cold Atmospheric Pressure Plasmas (CAPs) for Skin Wound Healing
In the past 20 years, cold atmospheric pressure plasmas (CAPs) have become a new promising way for many biomedical applications, such as disinfection, cancer treatment, root canal treatment, wound healing, and other medical applications. Among these applications, investigations of plasma for skin wound healing has gained huge success both in vitro and in vivo experiments, and also the mechanism behind it has been studied by many groups. In this chapter, we summarize the state-of-the-art progress in wound healing by CAPs. The plasma devices developed for wound healing, the interactions between plasmas and microorganisms/cells/tissues, the in vitro and in vivo treatments, the clinical trials, and biosafety issues are all included
Heterobasidion pathogenesis : Impact of effectome and co-infection on disease development and host defenses
In the boreal forest of Finland, spruce and pine form the basis for one of the largest industries contributing several billion euros in net export income yearly. However, a considerable proportion of the trees harvested are rotted and commercially less valuable largely caused by a species complex Heterobasidion annosum sensu lato (s.l.). The basidiomycete fungus H. parviporum threatens the health of boreal forest, especially Picea abies (L.) Karst (Norway spruce), by causing root and stem rot disease as comprehensively documented in our review article. We carried out a series of studies on the tree-fungal pathogen interactions, interspecific fungal interactions, and plant-endophyte-fungal pathogen interactions to identify vital traits or factors important for disease development and plant defense responses.
The availability of genome sequences of both H. parviporum and Norway spruce enabled the identification of small secreted proteins of the necrotrophic pathogen (HpSSPs) and plant defense-related genes in H. parviporum-Norway spruce interaction. In my first study, I investigated the functional role of HpSSP as pathogenicity factor. A hypothetical protein HpSSP35.8, a homolog of HaSSP30 from H. annosum, with necrosis-inducing activity in Nicotiana benthamiana was evaluated. Interestingly, not all homologs of cell death-inducing HaSSPs could trigger cell death in Nicotiana leaves. Hsr203J and HIN1, which are useful makers for hypersensitive response (HR) cell death, were found to be activated in the non-host N. benthamiana by HpSSP35.8 infiltration. The activation of Hsr203J and HIN1 revealed a form of SSP-associated HR triggered by HpSSP35.8. WRKY12, ethylene response factor (ERF1α) and a chitinase gene PR4, endochitinase.B, PI1 and NPR1 were induced in HpSSP35.8-infiltrated leaves, revealing their roles in defense response probably related to JA/ET-mediated signaling pathway. HpSSP35.8 coding gene was highly expressed in the pre-symptomatic phase of host infection. This suggests that HpSSP35.8 probably had an important role during fungal penetration and colonization. The defense-related genes in seedling roots induced by the pathogen infection were ERF1a and ERF1b, WRKY12, LURP1, PR1, PAL, which demonstrated that the phenylpropanoid pathway and the JA/ET-signaling pathway were activated in response to the pathogen.
In a follow-up study, I conducted a detailed analysis of H. parviporum effectome. H. parviporum was predicted to have nearly 300 small secreted proteins or effector candidates based on some of the characteristic features including secretion, expression in planta, cysteine and small protein size. The transcriptome profile analysis during fungal development and saprotrophic or necrotrophic growth showed that various HpSSPs were significantly induced during infection of woody trees, including HpSSP35.8. About a dozen small secreted proteins of H. parviporum were further selected to analyze their expression dynamics during interspecific fungal interaction with the endophyte Phialocephala sphaeroides and other fungi. Some HpSSP-coding gene expression varied according to the confronted fungus and the stage of interaction, and some others shared a common trend in expression over different interactions and stages. The formation of barrage zone and antagonism at distance during interspecific interaction indicated a combative and antagonistic impact. Some fungal species, which were overgrown by H. parviporum, had no inhibitory effect on the pathogen growth. Moreover, the expression of HpSSP-coding genes in the interaction with antagonism at distance was not as active as those in the interaction with barrage zone or overgrowth.
In paper III, it was observed that although the dark septate endophyte Phialocephala sphaeroides had no obvious in vitro antagonistic effect on the pathogen H. parviporum growth, it was found to promote the root development of Norway spruce seedlings. Co-infection was set up to investigate the effect of the host interaction with the endophyte and the pathogen H. parviporum on Norway spruce defense responses and fungal transcriptomic responses. RNA-seq analysis revealed that a large percentage of reads were undoubtedly mapped to Norway spruce, and a small part of reads were mapped to fungi. Phenylpropanoid biosynthesis was generally activated in Norway spruce seedlings in response to the endophyte inoculation (PaPs), pathogen infection (PaHp), and co-infection (PaPsHp), but the expression patterns of phenylpropanoid-related genes varied among different inoculations. Many gene members of PALs and peroxidase genes (POXs) were upregulated in PaPs, while not expressed in PaPsHp. This suggests that the subsequent infection with the pathogen was able to influence the phenylpropanoid metabolism modulated by the endophyte. Flavonoid biosynthesis pathway was also activated during fungal infection, with only 6 genes encoding enzymes related to CHI, F3’5’H, DFR, and ANR upregulated under a certain condition and 14 genes downregulated in PaHp, PaPs, PaPsHp. Multiple genes were uniquely upregulated in PaPs, which involved jasmonic acid (JA) signaling pathway, plant hormone signal transduction, MAPK signaling pathway and calcium-mediated signaling. It was concluded that the subsequent H. parviporum infection triggered reprogramming of host metabolism.
Further analysis showed that the transcript abundance of H. parviporum reduced dramatically in the presence of the endophyte in the co-infection seedlings, compared to those in the pathogen inoculation. Although the endophyte lost the antagonistic effect against H. parviporum at mycelium level, it seems to have a suppressive effect on H. parviporum at transcript level. With a slight decrease in the transcript abundance of P. sphaeroides in co-infection, P. sphaeroides had a transcriptome shift from fungal growth to stress response in the presence of the pathogen H. parviporum. Surprisingly, the roots of the pathogen-inoculated seedlings developed better than control seedlings, indicating H. parviporum was able to weakly improve root growth. We found that both the endophyte and the pathogen had genes associated with hormone, polyketide and Iron-sulfur proteins, which might involve auxin-related pathways responsible for plant growth promotion. Moreover, the DSE P. sphaeroides could produce indolic compounds in culture filtrate, and the endophyte culture filtrate was shown to promote the development of Arabidopsis root hair.Juurikäävät (Heterobasidion annosum sensu lato) ovat taudinaiheuttajia, jotka lahottavat kasvatettavia puita. Nämä sienet aiheuttavat siten metsänkasvatukselle mittavia tappioita Suomessa ja koko pohjoisella pallonpuoliskolla. Puiden ja juurikäävän vuorovaikutus tunnetaan yhä huonosti. Tutkin väitöskirjassani kuusen ja erilaisten sieniosakkaiden välisiä vuorovaikutuksia. Puissa elävät endofyyttiset sienet eivät aiheuta puille haittaa, toisin kuin patogeenit. Erityisesti työssä keskityttiin ominaisuuksiin, jotka liittyvät taudin kehitykseen ja kasvin puolustusreaktioihin. Sekä kuusen että kuusenjuurikäävän (H. parviporum) perimä on luettu. Tämä mahdollisti juurikäävän tuottamien ssp- proteiinien (small secreted proteins) ja kuusen puolustautumiseen liittyvien geenien tunnistamisen. Työssä käytettiin apuna tupakkakasvia (Nicotiana benthamiana), joka ei ole juurikäävän isäntäkasvi.
Vain osa HaSSP-proteiineista aiheutti solukuolemaa tupakkakasvissa. Ohjelmoidun solukuoleman merkkiominaisuudet aktivoituivat tupakkakasvissa, kun siihen ruiskutettiin HpSSP35.8 proteiinia. Kokonaisuutena geeniekspressio viittasi siihen, että puolustusvaste liittyy JA/ET-välitteiseen signaalireittiin. Kuusen juurissa ilmeni puolustukseen liittyviä geenejä, joiden perusteella fenyylipropanoidireitti ja JA/ET signaalireitit aktivoituvat puolustautumisessa. Juurikääpä tuotti runsaasti HpSSP35.8-geeniä tartunnan alkuvaiheissa.
Kuusenjuurikäävän perimä sisältää lähes 300 ssp-proteiinia, jotka voivat liittyä liittyvät vuorovaikutukseen kasvin kanssa. Kokeessa, jossa juurikääpä tartutettiin kuuseen keinotekoisesti, useat proteiinit olivat aktiivisia. Näistä proteiineista valittiin kymmenkunta proteiinia tutkimukseen, jossa vertailtiin niiden tuotantoa tilanteessa, jossa juurikääpä jakaa kasvualustan endofyytin (Phialocephala sphaeroides) ja muiden sienten kanssa. Proteiinien ilmeneminen vaihteli riippuen siitä, kasvoivatko viljelmät yhteen, vai kasvoiko juurikääpä kilpailevan sienen yli.
Vaikka endofyytti Phialocephala sphaeroides ei estänyt juurikäävän leviämistä, se edisti kuusen taimien juurten kehitystä. Kuusen juurten vastetta tutkittiin myös koeasetelmalla, jossa juuristoon tartutettiin sekä taudinaiheuttajaa, että endofyyttiä. Kuusi muodosti fenyylipropanoideja vasteena endofyytille, taudinaiheuttajalle, ja samanaikaiselle tartunnalle, mutta eri käsittelyjen välillä oli eroja. Tulokset viittasivat siihen, että taudinaiheuttaja vaikutti endofyytin aiheuttamiin muutoksiin fenyylipropanoidien tuotannossa.
Lisätutkimuksissa paljastui, että taudinaiheuttajan aktiivisuus vähensi huomattavasti endofyytin kasvua kuusentaimissa, mutta endofyytti vähensi juurikäävän geenien transkriptiota. Endofyytin geenien transkriptiossa oli nähtävissä stressivaste. Tutkimuksessa havaittiin yllättäen, että myös taudinaiheuttaja edisti juurten kasvua. Endofyyttiliuos myös lisäsi lituruohon (Arabidopsis) juurikarvojen muodostumista. Havaintoa selittänee se, että löysimme molemmilta sieniltä kasvuhormonien tuotantoon liittyviä geenejä
Identification of milk clotting activity from different sources of plant’s proteolytic enzymes / Siti Nursyafiqah Mohammad Zilan
Traditional bovine rennet used for cheese processing was high cost and limited in resource. A study was done to find replacement of the curdling activity of milk using different sources of plant’s proteolytic enzymes which are bromelain enzyme from the core of pineapple and papain enzyme from the leaves of papaya.
The method of milk clotting activity used to determine the time taken of the milk to coagulate caused by selected enzyme at specific temperature. The efficiency of calcium chloride is crucial to create isoelectric to cause aggregation of milk protein until it reach optimum pH for reaction occur where optimum concentration of calcium chloride for rennet, bromelain and papain are 0.03M,0.05M and 0.07M. Next, rennet have highest milk clotting rate and followed by papain and bromelain. Other than that, proteolytic activity is conducted using tyrosine as standard to determine the strength of protease at different enzyme seriel dilution ability to hydrolyse casein micelle by absorbance measurement from UV-VIS spectrophotometer. Rennet are reportedly have low proteolytic activity and papain has the highest rate of proteolytic activity compared to bromelain. Last but not least, milk clotting index is measured by ratio between milk clotting activity and proteolytic activity to determine the quality of protease to form curd of cheese. In conclusion, bromelain have highest milk clotting index when using pure enzyme that shows it is the best substitution to bovine rennet for cheese production. This research can be continue further in production of miniature cheese using the enzymes to understand the structure of cheese quality can be produced
The Impact of Child Abuse, Posttraumatic Cognitions, Machiavellianism and Emotional Suppression on Interpersonal Sensitivity and Psychiatric Comorbidity: A Latent Profile Analysis
Much of the detrimental effects child abuse can have on victims’ cognitions, personality traits and emotional regulation strategies have been documented; however, it is unclear whether these effects might coexist with posttraumatic cognitions, Machiavellianism, and emotional suppression to impact interpersonal sensitivity and psychiatric comorbidity. The present study aimed to address this knowledge gap. A sample of 553 Chinese university students from three universities completed the Childhood Trauma Questionnaire-short form, Posttraumatic Cognitions Inventory, Machiavellianism Personality scale, Courtauld Emotional Control Scale, Interpersonal Sensitivity Measure, and General Health Questionnaire-28. Using Latent Profile Analysis, a three-profile solution was achieved. Profile one (high maltreatment group) students reported high levels of abusive experiences, posttraumatic cognitions and Machiavellianism, but a moderate level of emotional suppression; Profile two (moderate maltreatment group) students had moderate levels of abusive experiences, posttraumatic cognitions, Machiavellianism and emotional suppression. Profile three (low maltreatment group) students had low levels of all of the preceding psychological constructs. Profile one reported significantly higher interpersonal sensitivity and psychiatric comorbidity. Students with child abuse experiences, who viewed themselves and others negatively, displayed some dark personality traits, exercised some control over their emotions, tended to be excessively sensitive to others’ behaviors and feelings and prone to psychological distress
Different subsidies’ impact on equilibrium decision-making of closed-loop supply chain
Purpose: An electronic product recycling not only needs the waste treatment company, but
also involves recycler and remanufacturer. It is significance for increasing subsidy modes and
promoting waste recycling to research the effect of government subsidies for recycler and
remanufacturer on the equilibrium of closed-loop supply chain.
Design/methodology/approach: In view of service competition, we build a Stackelberg
model which contains an original manufacturer, a recycler and remanufacturer and further
obtain the equilibrium decision of closed-loop supply chain. Based on this strategy model, we
analyze how two different subsidies to utilization rate of raw materials, the service level and the
demand of product affect on the terminal decision.
Findings: We compared the two different subsidy ways in closed-loop supply chain. Subsidy to
utilization rate of raw materials has no effect on the whole market demand for electronic
product; and subsidy on utilization rate of raw materials has no effect on the whole market
demand for electronic product.
Research implications: Under the conditions in which government can observe the
information of raw material utility and remanufacturing service level, if government decides to expand the market size, it could subsidize remanufacturer for different service level; Under the
conditions in which government can observe the information of raw material utility and
remanufacturing service level, if government want to improve utilization rate of raw materials,
stimulate sustainable development of industries of electronic product, it can subsidizes recycler
based on different utilization rate of raw materials.
Originality/value: We analyzed the closed-loop supply chain equilibrium, compared the
effects on it under different subsidy mechanism and offered some advises in order to provide
scientific support to promote electronic products recycling.Peer Reviewe
One-period pricing strategy of 'money doctors' under cumulative prospect theory
We focus on the interaction between investors and portfolio managers, employing a cumulative prospect theory approach to the investor's preferences. ln an original way, we model trust in the manager and the relative anxiety about investing in a risky asset. Moreover, we investigate how tmst and anxiety affect the manager's fee and the portfolios of cumulative prospect theory investors. The novelty of our contribution relative to previous work is that we rely on cumulative prospect theory(CPT) rather than the classical mean-variance framework. Moreover, our research differs from traditional CPT work through an improved value function that accurately characterizes the reduction in anxiety suffered by the CPT investors from bearing risk when assisted by the portfolio managers' help relative to when they lack such assistance. Our results differ in several respects from those obtained when using on classical preferences. First, the optimal fees are not symmetric. Specially, the dominant managers obtain higher fees than subordinate managers regardless of changes in risk of risky assets (a risky asset) and changes in the dispersion of trust in the population. Another difference is that these fees are not proportional to expected returns. ln particular, the optimal fees increase nonlinearly as risk of risky assets (a risky asset) increases and the dispersion of trust in the population increases.info:eu-repo/semantics/publishedVersio
The concept of self among Chinese university victims of child abuse: an interpretative phenomenological analysis
The impact of child abuse experiences on the concept of self has been documented, however, using the qualitative method to further understand the subjective experiences of victims’ self-concept has not been done. Ten participants aged 19 to 22 reporting a history of child abuse experiences provided subjective feelings of the effects following these experiences in the form of a semi-structured interview. Using interpretative phenomenological analysis (IPA), there were 5 superordinate themes, including self-perceptions, negative perceptions of others/ the world, difficulties in interpersonal relationships, emotional regulation skills and personal characteristics in the present study. The results showed that (1) victims had some negative perceptions of themselves and of others but also had some positive self-perceptions. (2) Victims had some maladaptive characteristics, such as amorality or manipulation, for self-protection and maintaining social harmony; (3) and they easily suppressed their non-anger emotions. (4) They encountered social and intimate relationship difficulties. The subjective feelings of child abuse victims explored many negative perceptions of the self and others and showed the sensitivity of rejection in interpersonal relationships. Some negative personal characteristics and emotional suppression were also found among victims
The dark septate endophyte Phialocephala sphaeroides suppresses conifer pathogen transcripts and promotes root growth of Norway spruce
Plant-associated microbes including dark septate endophytes (DSEs) of forest trees play diverse functional roles in host fitness including growth promotion and increased defence. However, little is known about the impact on the fungal transcriptome and metabolites during tripartite interaction involving plant host, endophyte and pathogen. To understand the transcriptional regulation of endophyte and pathogen during co-infection, Norway spruce (Picea abies) seedlings were infected with DSE Phialocephala sphaeroides, or conifer root-rot pathogen Heterobasidion parviporum, or both. Phialocephala sphaeroides showed low but stable transcripts abundance (a decrease of 40%) during interaction with Norway spruce and conifer pathogen. By contrast, H. parviporum transcripts were significantly reduced (92%) during co-infection. With RNA sequencing analysis, P. sphaeroides experienced a shift from cell growth to anti-stress and antagonistic responses, while it repressed the ability of H. parviporum to access carbohydrate nutrients by suppressing its carbohydrate/polysaccharide-degrading enzyme machinery. The pathogen on the other hand secreted cysteine peptidase to restrict free growth of P. sphaeroides. The expression of both DSE P. sphaeroides and pathogen H. parviporum genes encoding plant growth promotion products were equally detected in both dual and tripartite interaction systems. This was further supported by the presence of tryptophan-dependent indolic compound in liquid culture of P. sphaeroides. Norway spruce and Arabidopsis seedlings treated with P. sphaeroides culture filtrate exhibited auxin-like phenotypes, such as enhanced root hairs, and primary root elongation at low concentration but shortened primary root at high concentration. The results suggested that the presence of the endophyte had strong repressive or suppressive effect on H. parviporum transcripts encoding genes involved in nutrient acquisition.Peer reviewe
Sapphire optical fibre interferometric sensors
This thesis is mainly concerned with the development of single crystal fibre interferometric sensors. By studying the functional relationship between the angle of wedge-shaped air gap and the separation of consecutive fringes of equal thickness, results shows that the percentage difference of angles between the method of interference fringes and the direct calculated method is about 3.99%. Thus, a procedure of prototype was established to monitor the process of fabrication of a Fabry-Perot cavity. An intrinsic sapphire fibre-optic Fabry-Perot sensor was fabricated, and the functional relationship between the output of interference signal of the intrinsic sapphire fibre-optic Fabry-Perot sensor and temperature was deduced. The fitting equation, the functional relationship between temperature and the output of the number of interference fringes of the intrinsic sapphire fibre-optic Fabry-Perot sensor, was obtained by data fitting. There is a near linear relationship between the temperature measured and the output signal of the intrinsic sapphire fibre- optic Fabry-Perot sensor for the range of temperature 75 °C - 435 °C. An extrinsic sapphire fibre-optic Fabry-Perot sensor was fabricated, and the functional relationship between the output of interference signal of the extrinsic sapphire fibre-optic Fabry-Perot sensor and temperature was deduced. High temperature ceramic adhesive based on aluminum oxide was presented to solve the problem of unmatched thermal expansion between the support materials and the extrinsic sapphire fibre-optic Fabry-Perot sensor. Theoretical analysis showed that during the process of the fabrication of the interferometer cavity, the length of Fabry-Perot cavity for fabricating should be tightly controlled. Phase relationships between the output of the interference signal of a monolithic sapphire fibre-optic Fabry-Perot sensor and the angular frequency of sound wave was deduced. Some monolithic sapphire Fabry-Perot cavities were fabricated, and their internal surfaces were observed. The optical quality of the internal surface of the melted end of the sapphire Fabry-Perot cavities was assessed by Michelson interferometric testing. The experiments showed that interference fringes of equal inclination could be achieved if the internal surface of the monolithic sapphire Fabry-Perot cavities were approximately planar surface. Obviously, there is the potential to fabricate a monolithic sapphire fibre-optic Fabry-Perot sensor by the sapphire tube sheath method. Four problems are presented to discuss which should be solved in future in consideration to the structure and assembly of the monolithic sapphire fibre-optic Fabry-Perot sensor: This study in this thesis has elucidated the problems associated with procedures in fabrication, assembly, and test of sapphire fibre-optic Fabry-Perot sensor, and achieved greater insights into fabrication of the monolithic sapphire fibre-optic Fabry-Perot sensor which shows the market potential of such an approach in Aerospace and Automobile applications
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