The interaction between cationic amino groups on chitosan and anionic moieties such as sialic and sulfonic acids on the mucus layer is responsible for its mucoadhesiveness [16]. In addition, chitosan enhances epithelial permeability through the opening of tight junctions between epithelial cells [17]. Recently, it was reported that the covalent attachment of thiol groups to polymers greatly increases their mucoadhesiveness and permeation properties without affecting biodegradability [16, 18]. Thiolated

chitosan-modified nanoparticles are expected to be appropriate carriers for oral absorption of drugs [19–21]. Thiolated chitosan has many advantages as a carrier in nanoparticulate drug delivery systems. It is nontoxic, biocompatible, and biodegradable and has been proven to control the release of drugs, proteins, and peptides. It is soluble in aqueous media, avoids the use of organic solvents, and does not require further Epoxomicin mouse purification of nanoparticles [22]. Thus, thiolated chitosan was used in the present study to be absorbed on the nanoparticle surface by electrostatic forces of attraction between positive and negative charges. In this research, PLA-PCL was used to maintain the desirable mechanical strength of the polymer. Vitamin E d-α-tocopheryl polyethylene glycol 1000 succinate (Vitamin E TPGS, or simply TPGS) is

MK-2206 mw a water-soluble derivative of naturally sourced vitamin E, which is formed by esterification of vitamin E succinate

with polyethylene glycol 1000. Previous studies revealed that TPGS was able to improve drug permeability across biological membranes Carnitine dehydrogenase by inhibition of P-gp pumps and, thus, increase the drug absorption capability and decrease P-gp-mediated MDR in cancer cells [23–25]. In addition, TPGS was able to effectively inhibit the growth of human lung cancer cells in cell culture and in animal models [26]. The superior antitumor activity of TPGS is mainly due to its increasing ability to induce apoptosis in tumor cells [26–28]. A few studies have shown synergistic effects of combinations of TPGS with other antitumor drugs [27]. Furthermore, it has been found that TPGS-emulsified nanoparticles had higher encapsulation efficacy and cellular uptake, longer half-life, and higher therapeutic efficiency of the formulated drug than those emulsified by poly(vinyl alcohol), a commonly used emulsifier in nanoparticle formulation process [24]. Thus, we were inspired to fabricate a novel thiolated chitosan-modified PLA-PCL-TPGS nanoparticle as oral anticancer drug carrier for lung cancer chemotherapy. The chemical structure of PLA-PCL-TPGS random copolymer is shown in Figure 1[24]. Figure 1 Chemical structure and 1 H-NMR spectra of PLA-PCL-TPGS copolymer. (A) Chemical structure of PLA-PCL-TPGS copolymer; (B) typical 1H-NMR spectra of PLA-PCL-TPGS copolymer.

8 (3.1) days. Most patients were sent home (62%) after hospital discharge. These findings add substantially to the literature regarding

the effectiveness of ceftaroline in patients with renal dysfunction. However, consistent with the other subgroup analyses, the limited sample size and the potential for selection bias necessitate the need for additional verification prior to routine use in clinical practice. Another area of interest for clinicians is the ability of ceftaroline to treat MRSA CABP. Patients with MRSA CABP were specifically excluded from the FOCUS trials due to the inactivity of ceftriaxone against MRSA [2–4]. CAPTURE has afforded an opportunity to examine the use of ceftaroline for patients with CABP with positive cultures for MRSA [6]. SN-38 At the time of abstract presentation in 2013, there were a total of 39 patients with CABP with positive cultures for MRSA in CAPTURE. With regard to culture sites, MRSA was isolated from both blood and respiratory samples in three patients

(8%), respiratory samples only in 28 patients (72%), and blood samples only in 8 patients (21%). The cohort of patients with CABP with a positive MRSA culture was predominately male (n = 25, 64%) and the mean (SD) age was 59.0 (16.6) years. Similar to the other subgroups www.selleckchem.com/products/gsk3326595-epz015938.html examined, comorbidities were highly prevalent. Thirty-three patients (85%) had comorbidities including structural lung disease (56.4%), GERD (33.3%), history of smoking (25.6%), prior pneumonia (20.5%), and CHF (18.0%). There was an equal proportion of patients admitted to intensive care units and general practice units (51% vs. 49%). Nearly all patients (n = 36, 92%) received prior antibiotics before initiation of ceftaroline. Glycopeptides, cephalosporins, and penicillins were the most commonly used prior antibiotics (67%, 31%, and 31%, respectively). Half the patients (n = 20) received ceftaroline

as monotherapy, while the remainder received concurrent gylcopeptides (28%), quinolones (15%), and macrolides Mirabegron (8%). Patients were treated for a mean (range) of 7.3 days (range 1–30 days). The incidence of clinical success was 62% (n = 24). Similar to other investigations, clinical success was greater in those admitted to the general practice units relative to the ICU (74% vs. 50%, respectively). Source of pathogen isolation did not affect clinical cure (respiratory: 61%, blood: 64%). Ceftaroline monotherapy was associated with higher rates of clinical success as compared to combination therapy (75% vs 47%). Among those with a clinical failure, two patients were transferred to hospice care and one patient had a lobectomy due to a lung abscess. A high proportion of patients were discharged home (46%), while fewer were discharged to another care facility (44%).

PubMed 5. Tamagnini P, Troshina O, Oxelfelt F, Salema R, Lindblad P: Hydrogenases in Nostoc sp. Strain PCC 73102, a strain lacking a bidirectional enzyme. Appl Environ Microbiol 1997,63(5):1801–1807.PubMed 6. Forzi L, Sawers RG: Maturation of [NiFe]-hydrogenases Vactosertib in Escherichia coli. Biometals 2007. 7. Bock A, King PW, Blokesch M, Posewitz MC: Maturation of hydrogenases. Adv Microb Physiol 2006, 51:1–71.CrossRefPubMed 8. Jacobi A, Rossmann R, Bock A: The hyp operon gene products are required for the maturation of catalytically active hydrogenase

isoenzymes in Escherichia coli. Arch Microbiol 1992,158(6):444–451.CrossRefPubMed 9. Lutz S, Jacobi A, Schlensog V, Bohm R, Sawers G, Bock A: Molecular characterization of an operon (hyp) necessary for the activity of the three hydrogenase isoenzymes in Escherichia coli. Mol Microbiol 1991,5(1):123–135.CrossRefPubMed 10. Agervald A, Stensjo K, Holmqvist M, Lindblad P: Transcription of the extended hyp -operon in Nostoc sp. strain PCC 7120. BMC Microbiol 2008, 8:69.CrossRefPubMed 11. Gollin DJ, Mortenson LE, Robson Smoothened Agonist RL: Carboxyl-terminal processing may be essential for production of active NiFe hydrogenase in Azotobacter vinelandii. FEBS

Lett 1992,309(3):371–375.CrossRefPubMed 12. Menon NK, Robbins J, Vartanian MD, Patil D, Harry D, Peck J, Menon AL, Robson RL, Przybyla AE: Carboxy-terminal processing of the large subunit of [NiFe] hydrogenases. FEBS Lett 1993,331(1–2):91–95.CrossRefPubMed 13. Rossmann R, Sauter M, Lottspeich F, Böck A: Maturation of the large subunit (HYCE) of Escherichia coli hydrogenase 3 requires nickel incorporation followed by C-terminal processing at Arg537. Eur J Biochem 1994,220(2):377–384.CrossRefPubMed 14. Magalon A, Bock A: Dissection of the maturation reactions of the [NiFe] hydrogenase

Lonafarnib concentration 3 from Escherichia coli taking place after nickel incorporation. FEBS Lett 2000,473(2):254–258.CrossRefPubMed 15. Thiemermann S, Dernedde J, Bernhard M, Schroeder W, Massanz C, Friedrich B: Carboxyl-terminal processing of the cytoplasmic NAD-reducing hydrogenase of Alcaligenes eutrophus requires the hoxW gene product. J Bacteriol 1996,178(8):2368–2374.PubMed 16. Wünschiers R, Batur M, Lindblad P: Presence and expression of hydrogenase specific C-terminal endopeptidases in cyanobacteria. BMC Microbiol 2003,3(8):8.CrossRefPubMed 17. Fritsche E, Paschos A, Beisel H-G, Böck A, Huber R: Crystal Structure of the Hydrogenase Maturationing Endopeptidase HYBD from Escherichia coli. J Mol Biol 1999,288(5):989–998.CrossRefPubMed 18. Maier T, Bock A: Generation of Active [NiFe] Hydrogenase in Vitro from a Nickel-Free Precursor Form. Biochemistry 1996,35(31):10089–10093.CrossRefPubMed 19. Theodoratou E, Paschos A, Magalon A, Fritsche E, Huber R, Böck A: Nickel serves as a substrate recognition motif for the endopeptidase involved in hydrogenase maturation. Eur J Biochem 2000, 267:1995–1999.CrossRefPubMed 20. Axelsson R, Oxelfelt F, Lindblad P: Transcriptional regulation of Nostoc uptake hydrogenase.

After removing the supernatants, the bacterial pellets were washed twice with double distilled water. After second wash in double PCI-32765 in vivo distilled water, bacterial samples were stored at −70°C until lyophilisation. The samples for FTIR analysis were first grounded into fine particles using mortar and pestle. The 1 mg of each sample was then mixed with 100 mg potassium bromide (KBr) which extensively dried

in microfuge tubes using a lyophiliser. These mixtures have been dried for an additional 2 h in the same microfuge tubes. The KBr based pellets were then compressed into a thin disk by establishing pressure of 100 kg/cm2 (1200 psi) for about 8 min. FTIR spectroscopy and data analysis The FTIR spectroscopy data were analysed as previously described by Garip et al. [21] with a small modification. Pellets were scanned at 4 cm-1 resolution with 100 scans in the spectral range of 4000–500 cm-1 at room temperature. The sample compartment in the FTIR

spectrometer was continuously purged with dry air to prevent water vapour. Analysis of the spectral data was performed by using Grams 32 (Galactic Industries, Salem, NH, USA) software. The spectral range of 4000–500 cm-1 was analyzed. The band positions were measured according to the center of weight. The averages of the spectra belonging to the same experimental groups, baseline correction, normalisation and the band areas were obtained by using the same software program. The average spectra and normalisation process were applied only for visual representation of the differences, however for the determination of the spectral parameters find more and calculation of mean values and statistical analysis each baseline corrected original spectrum was taken into consideration. Statistics The software STATGRAPHICS Plus, version 4.0 (Copyright Manugistics Inc., Rockville, Md., USA) was used to perform the statistical

analysis. Levels of significance (p < 0.05) of main treatments and their interactions were calculated by analysis of variance after testing for normality www.selleck.co.jp/products/Adrucil(Fluorouracil).html and variance homogeneity. Results and discussion Bacterial identity Results from this study indicated the rice strains should be identified as A. oryzae with Biolog similarity of 0.72 to 0.73, FAME similarity of 0.73 to 0.74, 16 S rRNA sequence similarity of 99% and confirmed by both pathogenicity tests and species-specific PCR, while the watermelon and melon strains should be identified as A. citrulli with Biolog similarity of 0.70 to 0.73, FAME similarity of 0.73 to 0.74, 16 S rRNA sequence similarity of 99%, and confirmed by both pathogenicity tests and species-specific PCR in the newly proposed classification of subspecies of A. avenae. However, in general, the two species of Acidovorax were high similar, and difficult to be differentiated based on Biolog and FAME profile as well as 16 S rRNA sequence analysis.

Nucl Acids Res 2006, 34:D446–451.PubMedCrossRef Authors’ contributions ZLL designed SRT2104 mw the qRT-PCR array and conceived the experiment. MM performed strain adaptation, experimental fermentation, sample collection, RNA extraction, qRT-PCR and data analysis. ZLL and MM analyzed the data and wrote the manuscript. All

authors read and approved the final manuscript.”
“Background Microorganisms usually exist in populations of huge sizes and are highly prone to long-distance dispersal by vectors such as wind, water, animals and humans [1–5]. Obvious barriers to dispersal are lacking, especially in the marine habitat [4–8]. The ubiquitous dispersal of microorganisms has been a prevalent view since the turn of the last century, summarized in the statement “”everything is everywhere, but, the environment selects”" [9,

10]. This view has been challenged however, by investigations of environmental DNA clone libraries as a large number of cryptic species and restricted biogeographies have been revealed [11–20]. High levels of genetic diversity have been found, even within the slowly evolving small ribosomal subunit gene [21, 22]. However, as more localities are being investigated and the variety of sampling strategies increase, the geographic ranges of many microorganisms have been expanded, showing that under-sampling of the diversity can cause a false impression of endemism [see [4, 5]]. Some surveys have therefore interpreted the diversity as consistent with the “”Moderate AZD8931 in vitro Endemicity Model”" (MEM), which states that some microbial lineages do in fact have a global distribution, but that

PI-1840 there also exists species with restricted dispersal and local adaptations [4, 23–25]. The vast majority of 18S rDNA environmental surveys conducted so far have involved universal primers designed to capture the broadest diversity of eukaryotes possible. However, much diversity is most likely overlooked by applying only a single pair of universal primers [26–28]. This could be due to a number of reasons, e.g. the primers are less suitable for some groups of organisms, there are great variations in rDNA copy number, as well as bias introduced in the PCR reaction. One of the most efficient approaches to address these problems has been to apply a group-specific PCR strategy with primers targeting the particular taxonomic group of interest [29–32]. These studies have shown that the use of such primers is detecting far more diversity than the universal approach. Telonemia is one of the groups of unicellular eukaryotes that are frequently detected in marine 18S rDNA environmental clone libraries, but usually represents only a relatively small part of the total diversity [11, 33–36].

When branched chain find more amino acids are depleted, DNA affinity decreases allowing the initiation of transcription. Although usually considered to be a repressor, CodY activates expression of acetate kinase [21] and bsfF, which is a small RNA in B. subtilis[22]. In S. pyogenes, CodY controls the expression of genes involved in the response to nutritional stress, including genes encoding exoproteins. The

transcript levels of 34 genes were previously compared between a wild-type strain of S. pyogenes and a codY mutant derivative by using quantitative reverse transcriptase PCR (qRT-PCR) [18]. Eleven of the genes were predicted to encode secreted proteins. The expression of four of these genes (grab sagA sdaB/mf-1, and speB) was greater in the wild-type strain compared to the mutant strain, while the expression of the remaining seven was less (nga prtS scl scpA ska slo speH). Subsequently, by using DNA microarrays, inactivation of codY in S. pyogenes was found to alter the transcription of approximately 17% of genes in the chromosome, click here including several that encoded exoproteins [23]. Together, the results indicate that CodY is a global regulator controlling the transcription of a variety of

genes, including some encoding exoproteins, which are likely to influence host-pathogen interactions [18, 23]. The purpose of this study was to compare the exoproteins of a wild-type strain of S. pyogenes to a codY mutant strain to identify potential differences derived either at the transcriptional or post-transcriptional level. The results confirmed, at the protein level, several differences in expression previously predicted by transcript analyses and identified additional exoproteins with altered abundance following the deletion of

codY. Results Analysis of exoproteins by SDS-PAGE As an initial step to identify differences in exoprotein production between a codY mutant and a wild-type strain of S. pyogenes, the strains were grown to the stationary phase of growth and culture supernatant proteins (CSPs) were analysed by using SDS-PAGE gel electrophoresis. There was no difference in either the growth rate or growth yield of the two strains (Figure 1). mafosfamide Separation of CSPs by using SDS-PAGE showed several differences in the amounts of specific proteins (Figure 2). Seven protein bands were excised from the gel and analysed with tandem mass spectrometry (MS/MS; Additional file 1: Table S1, Additional file 2, Table S2). The results indicated that hyalurondidase (HylA; Spy49_0811c), which degrades hyaluronic acid present in the extracellular matrix of host tissue and the bacterial capsule, a 5’-nucleotidase (Spy49_0686c), a secreted protein with similarity to amidases (Spy49_0015), and a hypothetical protein possessing a type II secretion signal (Spy49_0816) were more abundant in the supernatant fluid obtained from the wild-type strain (Figure 2).

Conclusion To our knowledge this is the first

study that visualized hemostatic alterations in influenza Torin 2 ic50 virus infection in a controlled animal model resembling human disease. The drastic changes seen in a very short time period might be the result of consumptive coagulopathy. Interestingly even in the seasonal influenza group, with only relatively mild clinical ‘flu’ symptoms, infection had significant effects on systemic hemostasis. These results might help in further understanding the role of influenza infection in acute cardiovascular disease, while future research could indicate if alterations in coagulation have an important role in influenza pathogenesis. Methods Experimental design Samples from 104, 11-month old, male, outbred ferrets (Mustela putorius furo) were used

for this experiment as described previously [21]. Animals were inoculated both intratracheally and intranasally with one of three influenza viruses, or with control material (mock). All three influenza virus strains had been directly derived from patient isolates. For seasonal influenza, H3N2 virus (A/Netherlands/177/2008) [18], for pandemic influenza, pH1N1 influenza virus (A/Netherlands/602/2009) [44] and for highly pathogenic avian influenza virus (HPAI) NVP-BSK805 molecular weight the H5N1 strain (A/Indonesia/5/2005) were used [45]. Virus stocks were passaged three times in Madin-Darby Canine Kidney (MDCK) cells and titrated according to standard methods. The viruses were clarified and reached an infectious virus titer of 107.4 median tissue culture infectious dose (TCID50) per ml for H3N2 virus, and 107.8 TCID50 for both pH1N1 and HPAI-H5N1 virus [46]. The inoculum of the control group consisted Acyl CoA dehydrogenase of MDCK culture derived material which had been subjected to the same procedure to control

for respiratory tract damage not related to replicating virus [21]. Inocula consisted of 3 mL volumes of virus preparations with 106 TCID50 given per animal partly intratracheally and partly intranasally. Ferrets were randomly selected for any of the predefined time points before the start of the experiment. Four ferrets were euthanized per time point. Each ferret was sampled twice: before inoculation and when sacrificed. This resulted in 104 samples analyzed before inoculation (28 mock, 28 H3N2, 28 pH1N1 and 20 H5N1) and 4 samples per virus per time point (Table 4). During euthanasia, citrated blood was drawn by cardiac puncture in 3 mL citrate tubes and plasma was prepared for testing in coagulation assays. Table 4 Distribution of the ferrets used in this study Group P.I. ½ dpi 1 dpi 2 dpi 3 dpi 4 dpi 7 dpi 14 dpi X Mock 28 4 4 4 4 4 4 4   H3N2 28 4 4 4 4 4 4 4 pH1N1 28 4 4 4 4 4 4 4 H5N1 20 4 4 4 4 4 0 0 Total 104 16 16 16 16 16 12 12 Z Y Ferrets were sampled before inoculation with a mock control suspension, H3N2-, pH1N1- or H5N1 influenza virus.

Testing a larger collection of strains from diverse origins could address this question. Diverse methods have been proposed for the molecular typing of bacteria in the genus Ochrobactrum. ITS1 sequencing and rep-PCR have been successfully used to assess the level of microdiversity in the genus as well as to cluster the strains according to the species [12, 13]. However, within the species O. anthropi there was no correlation between

rep- or ITS1-based clusters and origin of the strains. In the collection tested, MLST data and multi-locus-based phylogeny provided CP673451 manufacturer evidence of a clonal complex associated to human beings. To strengthen this evidence, the question of the representativeness of the human strains included in the MLST analysis should be addressed. Most clinical strains originated from France (n = 34) but they have been isolated in diverse regions and at different times from 1998 to 2007. We also included 9 geographically unrelated clinical strains isolated in

Scandinavia, United Kingdom or Louisiana (USA) from 1971 to 1995. Seven of them belonged to the major complex MSCC4/eBCC4 beside most of the French clinical isolates. This indicated that MSCC4/eBCC4 could be considered as Captisol chemical structure a human-adapted subpopulation rather than a geographic subpopulation. The mean genetic diversity calculated from the seven loci showed no significant differences between clinical isolates and isolates from all other various origins. This is also the case for the number of STs per strain. The genetic

diversity of the clinical population was confirmed at the genomic level since all the clinical strains displayed different pulsotypes indicating that they were epidemiologically unrelated. Therefore, epidemiological, genetic and genomic data exclude a bias in strain sampling and enhance the robustness of the human-associated subpopulation described herein. PFGE typing appeared highly discriminative in the species O. anthropi since only 2 strains originating from the same environmental sample displayed Amisulpride the same pulsotype. None of the isolates originating from one hospital displayed the same pulsotype. This wide genomotype diversity observed here confirmed previous data showing the genomic plasticity of O. anthropi [28]. Genomic rearrangements in plastic genomes are considered as rapid evolution mechanisms, named micro-evolution with respect to the time-scale, that could be involved in rapid adaptation processes to a particular niche [42]. Restriction fragment length polymorphism in PFGE detected genomic modifications such as rearrangements and horizontal genetic transfer events rather than single nucleotide polymorphisms [43]. The higher discriminative power of PFGE suggested that large rearrangements occurred at higher rates than intragenic point mutations in housekeeping genes in O. anthropi.

The majority of vascular trauma in USA, South America and military conflict areas in Europe was penetrating trauma reaching up to 90% in some reports [15–17]. The actual incidence of vascular trauma in most European countries is unknown. Finland has an

annual incidence of 1.3 per 100,000 inhabitants while Sweden has an incidence of 2.3 per 100,000 inhabitants [9]. Our incidence of major vascular trauma due to road traffic collisions alone is 1.87 cases/100 000 inhabitants per year. The studies from Sweden and Finland included all vascular injury patients admitted to hospitals. About 20% were caused by blunt trauma. In contrast our study was limited only to hospitalized vascular injury in road traffic collisions. Only 34% of trauma in our community is caused by RTC which indicates that this website vascular trauma in general is even much higher than Finland and Sweden [18]. It may be argued that the number of patients of this study is small. Nevertheless we think that the data was very accurate as it captured prospectively

all injuries in all age groups with their detailed mechanism of injury in a specific population over a specific time. Analyzing the biomechanics of crashes is important. About 90% of injuries can be clinically predicted if the biomechanics of RTC was well understood [19]. This will help reducing missed injuries. It is important to note that the majority of vascular injuries were in the upper part of the body MI-503 purchase (upper limb and thorax) similar to other studies [9, 12, 20]. All thoracic aortic injuries in our study occurred in pedestrians hit by moving vehicles. These are acceleration injuries in which the moving aortic arch is accelerated compared to the

fixed part. We have recently shown that injury severity of RTC patients was higher for non vehicle occupants especially pedestrians, who also accounted for most deaths [5]. The risk of thoracic aortic injury was significantly higher with side-impact crashes and particularly if the occupants were unbelted [21] because side impact hits the weak side of the vehicle. None of our car occupants was wearing seatbelts. If an occupant was not restrained and had a front impact collision, he/she will lean forward [22–24] and may try to protect him/herself with his/her upper limbs leading to their fracture and major vascular injuries of the upper limbs as they cannot tolerate the impact of energy Defining Histamine H2 receptor the incidence and mechanism of vascular trauma would help in adopting preventive strategies and directing resources in this part of the world. Trauma centers should be well equipped with an angiographic suite, interventional radiologists, and a vascular team to optimize clinical outcome of these life-threatening situations. The most affordable, effective and cheapest way to reduce the burden of injury is prevention [25]. Injury prevention is usually highly cost effective saving both medical costs and lives [26]. We should adopt an epidemiological approach if we are serious in preventing these injuries.

The name constitutional NPQ (photophysical learn more decay) suggests that this does not vary significantly

with different irradiances. This is indeed observed in a number of higher plant studies (Ahn et al. 2009; Guadagno et al. 2010). These latter studies also expanded the analysis of the portioning of quantum efficiencies to a better description of the importance of qE, qI and qT in ΦNPQ. Our data clearly show that in the unicellular alga D. tertiolecta, Φf,D varies with irradiance. In the block high light treatment Φf,D is higher in the light than in the darkness, but in the light the variability in Φf,D is limited. However, when the same procedure is followed for the stepwise increase in irradiance Φf,D shows large oscillations, in contrast to the situation described in higher plants. Unfortunately, we were able to find only one study in which energy apportioning was studied in algae. The unicellular microalgae Chlamydomonas raudensis showed variability

in constitutive (or non-regulated) NPQ, which increased as a function of the growth light intensity (Szyszka et al. 2007). Constitutive NPQ also showed variations due to exposure to different growth temperature conditions with variations that do not extend approximately 5% in a higher plant (Hendrickson et al. 2004). Neither of these studies employed the high temporal measurement frequencies that isometheptene we used, making it difficult to compare our studies to the literature. HDAC inhibitor drugs In this study, it can be clearly seen

that Φf,D responds rapidly to various PF conditions in D. tertiolecta. Nevertheless, as Φf,D increases when cells are exposed to sub-saturating PF during a dark–light transition, while other NPQ parameters decrease, it seems reasonable to suggest that Φf,D acts as an important short-term safety valve and can operate independently from other NPQ mechanisms. Further, it seems possible that similar responses operate when cells are exposed to high PF, but have not been detected in this study as response times might be so rapid that they occur between measurements conducted by the measurement protocol (13 s). The rapid, and xanthophyll cycle independent, fraction of qE can act as an efficient photoprotective mechanism in algae and might be attributed to PSII reaction centre quenching, whether this is due to charge recombination, direct P680+ quenching, spill-over or conformational changes in the PSII core subunits (Olaiza et al. 1994; Doege et al. 2000; Eisenstadt et al. 2008; Ivanov et al. 2008; Raszewski and Renger 2008). As constitutive thermal dissipation (Φf,D) originates in the PSII core (Ivanov et al. 2008), it can be concluded that D. tertiolecta is capable of rapidly changing PSII reaction core properties to avoid photodamage.