F1 F0 Research Articles

Pengaruh Penambahan Puree Labu Kuning terhadap Kadar Proksimat, Beta Karoten, dan Sifat Organoleptik Cookies Umbi Garut Bebas Gluten

Background: Arrowroot flour is one of the food ingredients that can be used to replace the use of wheat flour and is a gluten-free flour. Objective: The purpose of this study was to utilize arrowroot flour and pumpkin puree in the manufacture of gluten-free cookies that are organoleptically acceptable and have good nutritional content. Method: The experimental design used was a one-factor completely randomized design (CRD) with two replications. The factor in this study was the formulation of arrowroot flour and pumpkin puree which consisted of 3 levels and 1 control, namely F1 (53% : 47%), F2 (50% : 50%), F3 (47% : 53%)), and control F0 (0% : 0%). Results: the use of arrowroot flour and pumpkin puree had a significant effect on the moisture content, ash, protein, and beta carotene of cookies (p<0.05). The results of the hedonic test analysis and the hedonic quality of cookies significantly affected the color quality, taste quality of arrowroot, and texture quality (p<0.05). Conclusion: The selected cookie formulation is F1 with a nutritional content of 100 g, which is 527 kcal of energy; 5.78 g protein; fat 33.93 g; carbohydrates 49.61 g; and beta carotene 1204.5 mcg.Keywords: Arrowroot_flour, Beta_carotene, Cookies, Gluten, Yellow_pumpkin_puree.

Protective potential of fresh orange juice against zinc oxide nanoparticles-induced trans-placental and trans-generational toxicity in mice.

Due to the emerging applications of nanoparticles, human exposure to nanoparticles is unavoidable, particularly to zinc oxide nanoparticles (ZnO NPs), owing to their wide range of usage. The ongoing study aimed to evaluate trans-generational toxic potential of ZnO NPs through exposure to F0 mothers, in F1 pups and F1 mature offspring and the protective potential of fresh orange juice (OJ). Twenty-eight F0 mothers were randomly allocated into four groups (n = 7), control; untreated, dose group; exposed to ZnO NPs, dose+antidote group; coadministered ZnO NPs + OJ, antidote group; OJ, during the organogenetic period. Fifty percent of F0 mothers were subjected to cesarean sections on the 18th day of gestation and F1 pups were recovered, macro-photographed, and dissected for liver evisceration, while 50% of F0 mothers underwent standard delivery. After parturition, F1 offspring were examined, and the liver and blood samples were extracted. Observations showed that ZnO NPs exposure in F0 mothers in preparturition and postparturition resulted in decreased body weight, increased liver weight, and elevated levels of ALT and AST significantly p ≤ .05 as compared to the control and antidote groups. Histopathological analysis of maternal livers intoxicated with NPs showed the disruptive structure of central vein, hepatocytes, and Kupffer cells in F0 mothers, while F1 pups showed morphological deviations and distorted development of the liver tissue and congestion, in contrast to the control. F1 offspring of NPs exposed mothers, even at postnatal week 8 showed pyknotic nuclei and activated Kupffer cells in the liver sections against control. But in the case of the Dose+antidote group, alterations were less severe than in the dose group. It can be concluded that exposure to ZnO NPs instigates teratogenicity and hepatotoxicity in F1 pups, F0 mothers, and F1 offspring, respectively, while fresh orange juice acts as a remedial agent against the abovementioned toxicities.

Substitution of Tempeh Flour with Beetroot Flour (Beta vulgaris L) in Cookies as Alternative High Protein Snack

Background: Tempeh is a fermented soybean product which high in protein, that beetroot also contains protein and antioxidant compounds. The substitution of tempeh flour and beetroot flour for the cookies can increase the protein nutritional value in cookies. Objectives: This research was to determine the nutrition value of the selected formulation cookies (F1) based on the result of acceptability test of cookies substitution with of tempeh flour and beetroot flour which compared with the SNI standard for supplementary feeding (MP-ASI biscuits). Methods: This is an experimental research with completely randomized design (CRD) with 2 treatment for cookies F1 (substitution of 0.09% tempeh flour and 10% beetroot flour) and cookies F0 (without substitution tempeh flour and beetroot flour). Parameter observed were the nutritional value of cookies are protein, carbohydrate, fat, fiber, water value, and ash value with 3 repetitions. The result of the analysis will be compared the SNI standard for MP-ASI biscuits. Results: From the results of the analysis of the nutrition value of the F1 cookies, that the protein value 12.19%, carbohydrate value 69.19%, fat value 22.73%, fiber value 11.15%, water value 2.96%, and the ash value 2.25% according to SNI requirements for MP-ASI biscuits with protein value of not less than 6 grams per 100 grams. There is a significant difference in protein nutrition value between F0 cookies and F1 cookies. Conclusions: Cookies F1 has protein value, water value, ash value according to SNI standard while charbohydrate and fat value exceeds SNI standard. One serving (2 pieces of cookies equivalent to 20 grams) can meet 9 - 16% of protein needs in toddler 1 - 5 years.

Antioxidant Activity Test from Vegetable Tomato (Solanum lycopersicum) and Cherry Tomato (Solanum lycopersicum var. Cerasiforme) in Hand and Body Cream

Dry, scaly, rough skin conditions accompanied by wrinkles and black spots characterize the skin that experiences premature aging. One of the causes of premature aging is free radicals. These free radicals can be overcome with natural or artificial antioxidants. Natural antioxidants are found in fruits and vegetables, one of which is tomatoes. Tomatoes in direct use are less effective, so they are made in the form of hand and body cream. Production of vegetable tomato and cherry tomato extracts fruit extraction and maceration using 96% ethanol, then concentrated with a rotary evaporator until the extract is thick. The extracts of vegetable tomatoes and cherry tomatoes were then tested for phytochemical, antioxidant activity, and identification of compounds with LC-MS, then applied to hand and body cream with a concentration of 1% and 3% with codes F0, F1, F2, F3, and F4. Hand and body cream of tomato extract are tested by measuring pH, viscosity, specific gravity, total microbial Contamination, homogeneity and testing for antioxidant activity using the DPPH method. Phytochemical test results showed that flavonoid compounds were present in both extracts. The antioxidant activity of vegetable tomato ethanol extract was obtained with an IC50 value of 947.81ppm, and an IC50 value of 473.51 ppm was obtained for cherry tomato extract. From the LC-MS analysis, the compounds contained in cherry tomatoes, namely esculeoside A and B as cytotoxic activity, dehydrotomat as an antibacterial, kaempferol-3-O-rutinoside as an antioxidant, and tomatidine as an antibiotic. Antioxidant activity of hand and body cream, hand and body cream F4 (964.05 ppm), hand and body cream F3 (1001.97 ppm), hand and body cream F2 (1033.73 ppm), hand body cream F1 (1036.61 ppm), and hand and body cream F0 (1486.14 ppm). Hand and body cream cherry tomato extract 3%, formula 4 (F4), has the highest antioxidant activity. It can be concluded that the addition of extract concentration affects the antioxidant activity value of hand and body cream. Body cream F2 (1033.73 ppm), hand body cream F1 (1036.61 ppm), and hand and body cream F0 (1486.14 ppm). Hand and body cream cherry tomato extract 3%, formula 4 (F4), has the highest antioxidant activity. It can be concluded that the addition of extract concentration affects the antioxidant activity value of hand and body cream. Body cream F2 (1033.73 ppm), hand body cream F1 (1036.61 ppm), and hand and body cream F0 (1486.14 ppm). Hand and body cream cherry tomato extract 3%, formula 4 (F4), has the highest antioxidant activity. It can be concluded that the addition of extract concentration affects the antioxidant activity value of hand and body cream.

Blackout in the powerhouse: clinical phenotypes associated with defects in the assembly of OXPHOS complexes and the mitoribosome.

Mitochondria produce the bulk of the energy used by almost all eukaryotic cells through oxidative phosphorylation (OXPHOS) which occurs on the four complexes of the respiratory chain and the F1–F0 ATPase. Mitochondrial diseases are a heterogenous group of conditions affecting OXPHOS, either directly through mutation of genes encoding subunits of OXPHOS complexes, or indirectly through mutations in genes encoding proteins supporting this process. These include proteins that promote assembly of the OXPHOS complexes, the post-translational modification of subunits, insertion of cofactors or indeed subunit synthesis. The latter is important for all 13 of the proteins encoded by human mitochondrial DNA, which are synthesised on mitochondrial ribosomes. Together the five OXPHOS complexes and the mitochondrial ribosome are comprised of more than 160 subunits and many more proteins support their biogenesis. Mutations in both nuclear and mitochondrial genes encoding these proteins have been reported to cause mitochondrial disease, many leading to defective complex assembly with the severity of the assembly defect reflecting the severity of the disease. This review aims to act as an interface between the clinical and basic research underpinning our knowledge of OXPHOS complex and ribosome assembly, and the dysfunction of this process in mitochondrial disease.

Streptococcus mutans SpxA2 relays the signal of cell envelope stress from LiaR to effectors that maintain cell wall and membrane homeostasis.

Streptococcus mutans is a major etiologic agent of dental caries, which is the most common chronic infectious disease worldwide. S. mutans is particularly adept at causing caries due to its exceptional capacity to form biofilms and its ability to survive acidic conditions that arrest acid production and growth in many more benign members of the oral microbiota. Two mechanisms utilized by S. mutans to tolerate acid are: modulation of the membrane fatty acid content and utilization of the F1 F0 -ATPase to pump protons out of the cytosol. In this study, the role of the spxA2 transcriptional regulator in these two pathways, and overall cell envelope homeostasis, was examined. Loss of spxA2 resulted in an increase in the proportion of saturated fatty acids in the S. mutans membrane and altered transcription of several genes involved in the production of these membrane fatty acids, including fabT and fabM. Furthermore, activity of the F1 F0 -ATPase was increased in the ∆spxA2 strain. Transcription of spxA2 was elevated in the presence of a variety of membrane stressors, and highly dependent on the liaR component of the LiaFSR system, which is known to sense cell envelope stress in many Gram-positive bacteria. Finally, deletion of ∆spxA2 led to altered susceptibility of S. mutans to membrane stressors. Overall, the results of this study indicate that spxA2 serves a crucial role in transmitting the signal of cell wall/membrane damage from the LiaFSR sensor to downstream effectors in the SpxA2 regulon which restore and maintain membrane and cell wall homeostasis.

A comparative study on steady and fluctuating semi-occluded vocal tract exercises between phonation of/a/and/E/

Context: Semi-occluded vocal tract exercises (SOVTEs) helps to change the acoustic vocal tract impedance in relation to the glottal impedance, improving voice quality. SOVTE has been divided into two groups: steady and fluctuating SOVTEs based on their source of vibration and acoustic characteristics. Aims: The aim of the study was to examine and compare the difference between steady and fluctuating SOVTE with phonation of/a/and/E/on electroglottography and F1–F0 analysis. Settings and Design: Survey design. Study Type: Consort type of study. Materials and Methods: Hundred male participants within the age range of 18–25 years were selected for the study. All the participants were asked to phonate (a) and (E) vowels at a constant pitch for at least 3 s, then all samples were recorded. Assessment of contact quotient percentage value in electroglottography and PRAAT software were used for F1–F0 analysis. Data processing was done on Excel spreadsheet and scoring was processed by SPSS software. Statistical analysis used: One-way analysis of variance (ANOVA) in SPSS Statistics was used for statistical analysis. Results: Mean ± standard deviation and one-way ANOVA revealed that the significant difference was obtained at P

Mechanisms of C-ring protonation and flexible F1–F0 coupling in a mitochondrial ATP synthase

Mechanisms of C-ring protonation and flexible F₁–F₀ coupling in a mitochondrial ATP synthase

Within-generation and transgenerational plasticity of mate choice in oceanic stickleback under climate change.

Plasticity, both within and across generations, can shape sexual traits involved in mate choice and reproductive success, and thus direct measures of fitness. Especially, transgenerational plasticity (TGP), where parental environment influences offspring plasticity in future environments, could compensate for otherwise negative effects of environmental change on offspring sexual traits. We conducted a mate choice experiment using stickleback ( Gasterosteus aculeatus) with different thermal histories (ambient 17°C or elevated 21°C) within and across generations under simulated ocean warming using outdoor mesocosms. Parentage analysis of egg clutches revealed that maternal developmental temperature and reproductive (mesocosm) environment affected egg size, with females that developed at 17°C laying smaller eggs in 21°C mesocosms, likely owing to metabolic costs at elevated temperature. Paternal developmental temperature interacted with the reproductive environment to influence mating success, particularly under simulated ocean warming, with males that developed at 21°C showing lower overall mating success compared with 17°C males, but higher mating success in 21°C mesocosms. Furthermore, mating success of males was influenced by the interaction between F1 developmental temperature and F0 parent acclimation temperature, demonstrating the potential role of both TGP and within-generation plasticity in shaping traits involved in sexual selection and mate choice, potentially facilitating rapid responses to environmental change. This article is part of the theme issue 'The role of plasticity in phenotypic adaptation to rapid environmental change'.

Increased virulence in the locust-specific fungal pathogen Metarhizium acridum expressing dsRNAs targeting the host F1 F0 -ATPase subunit genes.

Metarhizium acridum is a host-specific fungal pathogen with great potential for locust control. However, the slow killing action of M. acridum has impeded its widespread application. To enhance fungal virulence, we constructed transgenic M. acridum strains that express double-stranded (ds)RNAs targeting the genes of the F1 F0 -ATP synthase α and β subunits in Locusta migratoria. The two host genes were transcriptionally suppressed in L. migratoria nymphs (instar V) infected by RNA interference (RNAi) strains targeting one or two subunit genes of the host ATP synthase, followed by reduced ATPase activity and ATP synthesis. Consequently, the RNAi strain targeting both subunit genes displayed high virulence that was 3.7-fold that in the wild-type strain. Our results demonstrate that dsRNA expression in M. acridum can cause host RNA silencing during infection and greatly enhances the fungal virulence through interference with critical host genes, highlighting a new strategy for augmentation of fungal virulence against insect pests. © 2018 Society of Chemical Industry.

Negative supercoiling of DNA by gyrase is inhibited in Salmonella enterica serovar Typhimurium during adaptation to acid stress.

DNA in intracellular Salmonella enterica serovar Typhimurium relaxes during growth in the acidified (pH 4-5) macrophage vacuole and DNA relaxation correlates with the upregulation of Salmonella genes involved in adaptation to the macrophage environment. Bacterial ATP levels did not increase during adaptation to acid pH unless the bacterium was deficient in MgtC, a cytoplasmic-membrane-located inhibitor of proton-driven F1 F0 ATP synthase activity. Inhibiting ATP binding by DNA gyrase and topo IV with novobiocin enhanced the effect of low pH on DNA relaxation. Bacteria expressing novobiocin-resistant (NovR ) derivatives of gyrase or topo IV also exhibited DNA relaxation at acid pH, although further relaxation with novobiocin was not seen in the strain with NovR gyrase. Thus, inhibition of the negative supercoiling activity of gyrase was the primary cause of enhanced DNA relaxation in drug-treated bacteria. The Salmonella cytosol reaches pH 5-6 in response to an external pH of 4-5: the ATP-dependent DNA supercoiling activity of purified gyrase was progressively inhibited by lowering the pH in this range, as was the ATP-dependent DNA relaxation activity of topo IV. We propose that DNA relaxation in Salmonella within macrophage is due to acid-mediated impairment of the negative supercoiling activity of gyrase.

Disgust expressive speech: The acoustic consequences of the facial expression of emotion

This study investigated how the facial expression of disgust may affect the acoustics of speech. In terms of a pathogen avoidance mechanism, the expression of disgust would seem to require speech to be produced with a smaller mouth opening than neutral speech, hence lowering the formant frequencies. This hypothesis was tested by comparing how lip configuration (i.e., height, width and size of the lip area), fundamental frequency (F0) and the formants (F1 and F2) of the vowels (▪, ▪, ▪, ▪, ▪) changed when produced in neutral or disgust expressions. The vowels were extracted from 50 Cantonese sentences spoken by 10 (5 male) talkers; produced once in disgust and once more in a neutral tone of voice. The results support the notion that the facial expression of emotions may have a role in shaping the acoustic properties of the vocal expressions of emotions. Mixed effects logistic regression models revealed that in disgust, vowels were produced with lower lip height, lower F1, F2, and higher F0 than neutral speech.

Comprehensive mathematical model of oxidative phosphorylation valid for physiological and pathological conditions.

We developed a mathematical model of oxidative phosphorylation (OXPHOS) that allows for a precise description of mitochondrial function with respect to the respiratory flux and the ATP production. The model reproduced flux-force relationships under various experimental conditions (state 3 and 4, uncoupling, and shortage of respiratory substrate) as well as time courses, exhibiting correct P/O ratios. The model was able to reproduce experimental threshold curves for perturbations of the respiratory chain complexes, the F1 F0 -ATP synthase, the ADP/ATP carrier, the phosphate/OH carrier, and the proton leak. Thus, the model is well suited to study complex interactions within the OXPHOS system, especially with respect to physiological adaptations or pathological modifications, influencing substrate and product affinities or maximal catalytic rates. Moreover, it could be a useful tool to study the role of OXPHOS and its capacity to compensate or enhance physiopathologies of the mitochondrial and cellular energy metabolism.

Comprehensive Effects of the Application of Water and Fertilizer Amount on CO2 Emission from Soils of Summer-maize Field

Field experiments were conducted to determine the effects of water and fertilizer amount on soil CO2 emissions by using the method of static chamber/gas chromatography in summer maize farmland ecosystem. Three factors (three irrigation levels including 90 mm, 76.5 mm and 63 mm, four nitrogen fertilizer levels including 300 kg·hm-2, 255 kg·hm-2, 210 kg·hm-2 and 0 kg·hm-2, and four phosphate fertilizer levels including 90 kg·hm-2, 76.5 kg·hm-2, 63 kg·hm-2 and 0 kg·hm-2) were designed in the experiment. The results showed that soil CO2 emission under different water and fertilizer conditions showed obvious seasonal fluctuation, the main and secondary peak appeared at jointing to tasseling stage and tasseling to grouting stage. The soil CO2 emissions were relevant to the supply levels of fertilizer and irrigation. In the high fertilizer F1 (N 300 kg·hm-2, P2O5 90 kg·hm-2) and low fertilizer F0.7 (N 210 kg·hm-2, P2O5 63 kg·hm-2) conditions, average soil CO2 emissions flux during the whole growth period of high water W1 (90 mm) was significantly higher than that of low water W0.7 (63 mm); the difference of soil CO2 emissions between medium water level W0.85 (76.5 mm) and low water level was not significant under medium and low nutrient condition F0.85 (N 255 kg·hm-2, P2O5 76.5 kg·hm-2). Soil CO2 emissions intensity of high fertilizer F1 was significantly larger (by 14.82%) than that of low fertilizer F0.7 under high water supply W1 (P<0.05), and that of F0.85 was significantly bigger (by 8.03%) than that of F0.7 in the medium water supply(P<0.05), while the difference between treatments at low water level was not significant(P>0.05). Compared with nonfertilized treatment, soil CO2 cumulative emissions of the whole growth period with application of nitrogen fertilizer (210 kg·hm-2), phosphate fertilizer (63 kg·hm-2) and nitrogen mixed with phosphate fertilizer (210 kg·hm-2, 63 kg·hm-2) were significantly increased by 23.70%, 19.00% and 12.30%, respectively. And interaction effects between nitrogen and phosphorus fertilizer were extremely significant (P<0.01). Variance analysis of the interaction of water and fertilizer showed that the average soil CO2 fluxes of the whole growth period were not statistically significant but cumulative emissions of soil CO2 were significant (P<0.05) when the difference of supply level was 15%. In addition, soil CO2 flux and cumulative emission in the whole growth period were significant when supply differed by 30%. Obviously, soil CO2 emissions were promoted significantly by application of irrigation amount, nitrogen fertilizer, phosphorus rate and water and fertilizer interaction, while it was inhibited by nitrogen mixed with phosphorus. It was effective to regulate soil CO2 emission by water and fertilizer controlling measures.

Transcriptional profile of glucose-shocked and acid-adapted strains of Streptococcus mutans.

The aciduricity of Streptococcus mutans is an important virulence factor of the organism, required to both out-compete commensal oral microorganisms and cause dental caries. In this study, we monitored transcriptional changes that occurred as a continuous culture of either an acid-tolerant strain (UA159) or an acid-sensitive strain (fabM::Erm) moved from steady-state growth at neutral pH, experienced glucose-shock and acidification of the culture, and transitioned to steady-state growth at low pH. Hence, the timing of elements of the acid tolerance response (ATR) could be observed and categorized as acute vs. adaptive ATR mechanisms. Modulation of branched chain amino acid biosynthesis, DNA/protein repair mechanisms, reactive oxygen species metabolizers and phosphoenolpyruvate:phosphotransferase systems occurred in the initial acute phase, immediately following glucose-shock, while upregulation of F1 F0 -ATPase did not occur until the adaptive phase, after steady-state growth had been re-established. In addition to the archetypal ATR pathways mentioned above, glucose-shock led to differential expression of genes suggesting a re-routing of resources away from the synthesis of fatty acids and proteins, and towards synthesis of purines, pyrimidines and amino acids. These adjustments were largely transient, as upon establishment of steady-state growth at acidic pH, transcripts returned to basal expression levels. During growth at steady-state pH 7, fabM::Erm had a transcriptional profile analogous to that of UA159 during glucose-shock, indicating that even during growth in rich media at neutral pH, the cells were stressed. These results, coupled with a recently established collection of deletion strains, provide a starting point for elucidation of the acid tolerance response in S. mutans.

Variability in English vowels is comparable in articulation and acoustics.

The nature of the links between speech production and perception has been the subject of longstanding debate. The present study investigated the articulatory parameter of tongue height and the acoustic F1-F0 difference for the phonological distinction of vowel height in American English front vowels. Multiple repetitions of /i, ɪ, e, ε, æ/ in [(h)Vd] sequences were recorded in seven adult speakers. Articulatory (ultrasound) and acoustic data were collected simultaneously to provide a direct comparison of variability in vowel production in both domains. Results showed idiosyncratic patterns of articulation for contrasting the three front vowel pairs /i-ɪ/, /e-ε/ and /ε-æ/ across subjects, with the degree of variability in vowel articulation comparable to that observed in the acoustics for all seven participants. However, contrary to what was expected, some speakers showed reversals for tongue height for /ɪ/-/e/ that was also reflected in acoustics with F1 higher for /ɪ/ than for /e/. The data suggest the phonological distinction of height is conveyed via speaker-specific articulatory-acoustic patterns that do not strictly match features descriptions. However, the acoustic signal is faithful to the articulatory configuration that generated it, carrying the crucial information for perceptual contrast.

188 Using CG modeling in exploring the role of dynamical effects in catalysis and in simulating biological molecular machines

Studies of structure–function correlation of biological molecules involve in some cases the need to explore long-time processes and to sample complex multidimensional landscapes. Here, we review advances in such studies, starting by considering the proposal that enzyme catalysis involves dynamical effects (see Kamerlin & Warshel, 2010 for discussion and analysis). In order to explore the validity of this dynamical proposal, we used our renormalization approach that allows us to simulate the very long-time coupling between catalysis and conformational changes. The corresponding simulations have proved that dynamical effects cannot change the rate of the chemical steps in enzymes, as long as the chemistry is the rate-limiting step. The same analysis is then be applied to allosteric transitions and to the control of replication fidelity, reaching the same conclusions. Next, we describe the use of the renormalization method and electrostatic-based coarse-grained (CG) models to simulate the action of various challenging complex systems. It is shown that our CG model produces, for the first time, realistic landscapes for vectrorial process such as the actions of F1 ATPase (Mukherjee and Warshel, 2011) and F0 ATPase (Mukherjee and Warshel, 2012) . It is also shown that such machines are working by exploiting free energy gradients and cannot just use Brownian motions as the vectroial driving force. Finally, we outline a recent simulation of the tag of war between staled elongated peptide in the ribosome and the translocon.

Turnover of ATP synthase subunits in F1-depleted HeLa and yeast cells

Mitochondrial translation of the Saccharomyces cerevisiae Atp6p subunit of F1–F0 ATP synthase is regulated by the F1 ATPase. Here we show normal expression of Atp6p in HeLa cells depleted of the F1 β subunit. Instead of being translationally down-regulated, HeLa cells lacking F1 degrade Atp6p, thereby preventing proton leakage across the inner membrane. Mammalian mitochondria also differ in the way they minimize the harmful effect of unassembled F1 α subunit. While yeast mutants lacking β subunit have stable aggregated F1 α subunit in the mitochondrial matrix, the human α subunit is completely degraded in cells deficient in F1 β subunit. These results are discussed in light of the different properties of the proteins and environments in which yeast and human mitochondria exist.

Modular assembly of yeast mitochondrial ATP synthase

The mitochondrial ATP synthase (F(1)-F(0) complex) of Saccharomces cerevisiae is a composite of different structural and functional units that jointly couple ATP synthesis and hydrolysis to proton transfer across the inner membrane. In organello, pulse labelling and pulse-chase experiments have enabled us to track the mitochondrially encoded Atp6p, Atp8p and Atp9p subunits of F(0) and to identify different assembly intermediates into which they are assimilated. Surprisingly, these core subunits of F(0) segregated into two different assembly intermediates one of which is composed of Atp6p, Atp8p, at least two stator subunits, and the Atp10p chaperone while the second consists of the F(1) ATPase and Atp9p ring. These studies show that assembly of the ATP synthase is not a single linear process, as previously thought, but rather involves two separate but coordinately regulated pathways that converge at the end stage.

The developmental toxicity of 1‐methyl‐3‐octylimidazolium bromide on Daphnia magna

The developmental toxicity of 1-methyl-3-octylimidazolium bromide ([C(8)mim]Br) on Daphnia magna was investigated. The 24 and 48 h LC(50) values for [C(8)mim]Br in D. magna were 1.99 and 0.95 mg/L, respectively. A series of multigenerational toxicity tests were then used to explore [C(8)mim]Br effects in D. magna. [C(8)mim]Br significantly inhibited the body lengths of the F0 and F1 1st generations. After 21 days of exposure, [C(8)mim]Br lowered the reproductive ability of the F0 and F1 1st generations. In F1 3rd generation, 21 days of [C(8)mim]Br exposure prolonged the time to bear the first egg and the time to the first brood compared with the control, but the number of first-brood offspring and the number of broods produced by these animals were reduced. After the recovery period all the reproductive parameters returned to normal in F1 1st generation except for the number of broods. The dead neonates increased with prolonged exposure and increasing concentrations, and the dead neonates of the F1 3rd generation went far beyond that of the F1 1st and F0 generations. The intrinsic rate of natural increase (r) values of the three D. magna generations significantly decreased after exposure to higher concentrations of [C(8)mim]Br compared with control groups. Collectively, these results suggest that [C(8)mim]Br exerts a toxic effect on the development of D. magna. This study also highlights the importance of systematically evaluating the potential effects of aquatic ecosystems of ionic liquids that may be released into bodies of water.