Kırmızı derililerin esiri

Mahmut Cahit'in Yeni Yol'da tefrika edilen Kırmızı Derililerin Esiri adlı roman

Photosynthesis vs Irradiance (P vs I) curves for wild type and <i>npq4lhcsr1</i> acclimated to different light regimes.

<p>Wild type (black circles) and the <i>npq4lhcsr1</i> mutant (white squares) acclimated to either 50, 400, 860 μmol photons m^-2- s^-1 or a sinusoidal light regime (data collected 6 hours after dawn) were exposed to consecutive, increasing intensities of red light. Oxygen concentrations and PAM fluorescence were measured simultaneously. Data represent means ± s.d. (n = 3–6).</p

<i>npq4lhcsr1</i> growth rate under continuous and sinusoidal conditions.

<p>(A) <i>Chlamydomonas</i> exponential growth rates determined by cell counts collected over 2–3 days of growth. Symbols (*) represent significant differences from wild type within light acclimated states based on an un-paired t-test (p < 0.05). Data represents means + s.d. (n = 7–9) (B) Light levels measured across the 12:12 light dark cycle used for the sinusoidal light regime.</p

Thiobarbituric acid reactive substance (TBARS) concentrations per 10⁷ cell for wild type and <i>npq4lhcsr1</i> acclimated to different light regimes.

<p>Data represents the mean ± SD (n = 3–6). Symbols (*) represent significant differences from wild type within light acclimated states based on an un-paired t-test (p < 0.05).</p

Total organic carbon (TOC) accumulation across a 12 hour sinusoidal light regime.

<p>(A) shows pg TOC cell^-1, (B) shows Cell volume (μm³) of cells measured and (C) shows pg TOC normalized to cell volume. Data represents the mean ± SD (n = 5). Symbols (*) represent significant differences between wild type and <i>npq4lhcsr1</i> for each time point based on an un-paired t-test (p < 0.05).</p

Distribution of cell divisions per progenitor cell during growth in sinusoidal light conditions.

<p>Cell division number was quantified for 3 consecutive days in single replicate wild type (A) and <i>npq4lhcr1</i> (B) cultures. Wild type cells averaged 2.2 divisions per night and <i>npq4lhcsr1</i> averaged 1.9 divisions per night across the three nights measured.</p

A mutant of <i>Chlamydomonas</i> without LHCSR maintains high rates of photosynthesis, but has reduced cell division rates in sinusoidal light conditions

<div><p>The LHCSR protein belongs to the light harvesting complex family of pigment-binding proteins found in oxygenic photoautotrophs. Previous studies have shown that this complex is required for the rapid induction and relaxation of excess light energy dissipation in a wide range of eukaryotic algae and moss. The ability of cells to rapidly regulate light harvesting between this dissipation state and one favoring photochemistry is believed to be important for reducing oxidative stress and maintaining high photosynthetic efficiency in a rapidly changing light environment. We found that a mutant of <i>Chlamydomonas reinhardtii</i> lacking LHCSR, <i>npq4lhcsr1</i>, displays minimal photoinhibition of photosystem II and minimal inhibition of short term oxygen evolution when grown in constant excess light compared to a wild type strain. We also investigated the impact of no LHCSR during growth in a sinusoidal light regime, which mimics daily changes in photosynthetically active radiation. The absence of LHCSR correlated with a slight reduction in the quantum efficiency of photosystem II and a stimulation of the maximal rates of photosynthesis compared to wild type. However, there was no reduction in carbon accumulation during the day. Another novel finding was that <i>npq4lhcsr1</i> cultures underwent fewer divisions at night, reducing the overall growth rate compared to the wild type. Our results show that the rapid regulation of light harvesting mediated by LHCSR is required for high growth rates, but it is not required for efficient carbon accumulation during the day in a sinusoidal light environment. This finding has direct implications for engineering strategies directed at increasing photosynthetic productivity in mass cultures.</p></div

Protein abundance of D2, PsaC and Lhcb2 6 hours after dawn in sinusoidal cultures.

<p>(A) Immunoblot detection of D2, PsaC, and Lhcb2 for wild type and <i>npq4lhcsr1</i>. Lanes were loaded on an equal chlorophyll basis with biological replicates for wild type and <i>npq4lhcsr1</i> shown as A, B, and C. (B) Results from comparative densitometry of relative protein abundance normalized to ATP-B content. Data represent means ± s.d. (n = 3). Symbols (*) represent significant differences between mutant and wild type based on an un-paired t-test (p < 0.05).</p

Enabling Efficient and Confident Annotation of LC−MS Metabolomics Data through MS1 Spectrum and Time Prediction

Liquid chromatography coupled to electrospray ionization-mass spectrometry (LC–ESI-MS) is a versatile and robust platform for metabolomic analysis. However, while ESI is a soft ionization technique, in-source phenomena including multimerization, nonproton cation adduction, and in-source fragmentation complicate interpretation of MS data. Here, we report chromatographic and mass spectrometric behavior of 904 authentic standards collected under conditions identical to a typical nontargeted profiling experiment. The data illustrate that the often high level of complexity in MS spectra is likely to result in misinterpretation during the annotation phase of the experiment and a large overestimation of the number of compounds detected. However, our analysis of this MS spectral library data indicates that in-source phenomena are not random but depend at least in part on chemical structure. These nonrandom patterns enabled predictions to be made as to which in-source signals are likely to be observed for a given compound. Using the authentic standard spectra as a training set, we modeled the in-source phenomena for all compounds in the Human Metabolome Database to generate a theoretical in-source spectrum and retention time library. A novel spectral similarity matching platform was developed to facilitate efficient spectral searching for nontargeted profiling applications. Taken together, this collection of experimental spectral data, predictive modeling, and informatic tools enables more efficient, reliable, and transparent metabolite annotation

Characteristics of available models for <i>Phaeodactylum tricornutum</i>.

<p>Characteristics of available models for <i>Phaeodactylum tricornutum</i>.</p