Synthesis, Transport and Assembly of Wild Type and Mutant Precursors of the Small Subunit of the Chloroplast Enzyme Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase.

The small subunits of the chloroplast enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) are synthesized in the cytoplasm as precursors and transported into the organelle. The precursor (pS) of the small subunit (S) of RuBisCO contains an amino-terminal extension, the transit peptide, which is removed during or after transport into the chloroplast. The possible involvement of an RNA-containing component in transport of proteins into chloroplasts was investigated using a reconstituted system of pS translated in vitro and isolated chloroplasts. The post-ribosomal supernatant of the in vitro translation mixture and/or isolated chloroplasts were treated with ribonuclease prior to incubation for transport. Transport of pS was unaffected by the ribonuclease treatment indicating that an RNA is not involved in this process. While the targeting function of the pS transit peptide is well documented, the role in transport of the mature portion of the precursor has not been elucidated. Mutations in the mature portion of pS were constructed to assess the influence of the mature portion of the precursor on transport. Each mutant pS was analysed for transport into chloroplasts and assembly into RuBisCO. Mutations in the amino-terminal region of S severely interfere with transport of pS while mutations near the middle of S interfere to a lesser degree. These results indicate that the pS transit peptide is tailored for optimal transport of S. Assembly of mutant S into holoenzyme was poor, and a significant fraction was associated with RuBisCO binding protein which is postulated to assist assembly of the holoenzyme. Mutant S may be arrested at an intermediate step in the pathway of assembly. RuBisCO binding protein is homologous to the Escherichia coli groEL protein which binds unfolded proteins and mediates assembly of protein complexes. Fusion proteins containing pS or S fused to the carboxy-terminus of Staphylococcus protein A were expressed in E. coli and purified by protein A-affinity chromatography. GroEL protein copurified with protein A-pS and protein A-S but not protein A alone. Association of groEL protein with S expressed in E. coli indicates that RuBisCO binding protein, like groEL protein, may bind other unfolded or unassembled chloroplast proteins in addition to S

Process Development For Evaluating Utility Scale Solar At A Combined Heat and Power Facility

When considering the value of utility scale solar project and its impact, there are many variables to weigh and this can become a complex task without guidance. One key to a successful project is the ability to organize ideas and break down problems by sections. An array is only as valuable as the energy that it offsets. The rates that are offered in complex generation scenarios often vary from the more stable rates seen by residential spaces. Because of this, an investment in a solar array may not have the same straight forward payback as a residence. Essentially, the array’s value is restricted by the rate that the utility is charging, which is driven by predictive variables. This could either be beneficial to the payback of the investment or detrimental depending on the rates being avoided. By systematically analyzing weather data, utility pricing trends, performance, and energy escalation, a process was produced to deliver clarity as to the value of a utility scale solar array. With these topics covered, combined with a projection of value, an understanding of the opportunities ahead has become clear

Endperiodic maps via pseudo-Anosov flows

We show that every atoroidal endperiodic map of an infinite-type surface can be obtained from a depth one foliation in a fibered hyperbolic 3-manifold, reversing a well-known construction of Thurston. This can be done almost-transversely to the canonical suspension flow, and as a consequence we recover the Handel-Miller laminations of such a map directly from the fibered structure. We also generalize from the finite-genus case the relation between topological entropy, growth rates of periodic points, and growth rates of intersection numbers of curves. Fixing the manifold and varying the depth one foliations, we obtain a description of the Cantwell-Conlon foliation cones and a proof that the entropy function on these cones is continuous and convex.Comment: 50 pages, 12 figure

GravEn: Software for the simulation of gravitational wave detector network response

Physically motivated gravitational wave signals are needed in order to study the behaviour and efficacy of different data analysis methods seeking their detection. GravEn, short for Gravitational-wave Engine, is a MATLAB software package that simulates the sampled response of a gravitational wave detector to incident gravitational waves. Incident waves can be specified in a data file or chosen from among a group of pre-programmed types commonly used for establishing the detection efficiency of analysis methods used for LIGO data analysis. Every aspect of a desired signal can be specified, such as start time of the simulation (including inter-sample start times), wave amplitude, source orientation to line of sight, location of the source in the sky, etc. Supported interferometric detectors include LIGO, GEO, Virgo and TAMA.Comment: 10 Pages, 3 Figures, Presented at the 10th Gravitational Wave Data Analysis Workshop (GWDAW-10), 14-17 December 2005 at the University of Texas, Brownsvill

Evaluation de l’abondance des kystes des protozoaires flagellés dans les eaux usées exploitées en agriculture maraîchère en zone urbaine: Cas de la ville de Yaoundé (Cameroun)

Objectifs: Evaluer l’abondance des formes de dissémination des protozoaires flagellés dans les eaux usées exploitées en agriculture maraîchère dans certains bas fonds de la ville de Yaoundé.Méthodologie et résultats: Une étude a été menée de novembre 2013 à avril 2014 avec une phase d’identification et d’analyse bio-statistique de 2015-2016. Des échantillonnages des eaux ont été effectués. Les kystes des protozoaires flagellés ont été identifiés à l’aide de la coloration au Lugol après concentration des échantillons suivant la méthode par flottaison au sulfate de zinc. Les analyses biologiques des eaux révèlent la présence des kystes des Protozoaires flagellés avec des densités moyennes de 101 ± 70 kystes/L pour Giardia intestinalis, 34 ± 20 kystes/L pour Chilomastix mesnili, 3 ± 6 kystes/L pour Retortamonas intestinalis et 1 ± 3 kystes/L pour Enteromonas hominis. En général, les plus fortes densités de kystes sont enregistrées pendant la petite saison des pluies (172 ± 108 kystes/L). Les analyses statistiques montrent des corrélations significatives (P ≤ 0,05) entre la densité des kystes des protozoaires flagelles identifiées et les paramètres physico-chimiques tels que les MES, l’oxydabilité et la turbidité.Conclusions et application des resultsts: Les plantes doivent être bien lavées, désinfectées et bien cuites avant leurs consommations afin de réduire les risques sanitaires.Mots clés: kystes, protozoaires flagellés, agriculture maraîchère, bas-fonds et zone urbaineEnglish AbstractObjectives: To evaluate the abundance of environmental forms of flagellated protozoa in waste water that is exploited for urban wetland agricultural practices in Yaoundé.Methodology and results: A study was carried out from November 2013 to April 2014, with bioenvironmental and bio-statistical assessment from 2015-2016. Sampling took place on monthly basis. The flagellated protozoan cysts were identified by lugol coloration after concentrating the samples according to the method -of flotation using zinc sulphate. Biological analysis of water showed the presence of flagellated protozoan cysts with average densities of (101 ± 70 cysts/L) for Giardia intestinalis, Chilomastix mesnili (34  ± 20 cysts/L), of Retortamonas intestinalis (3 ± 6 cysts/L) and of Enteromonas hominis (1 ± 3 cysts/L). Generally, the highest cysts densities were registered during the short rainy season (172 ± 108 cysts/L). The Statistical analysis showed positive correlations (P ≤ 0, 05) between the density of these cysts and physic-chemical variables such as suspended solids, oxydability and turbidity. This testifies the importance of colloidal or suspended particles in the transportation of micro-organisms in water.Conclusion and application of results: In view of these results and the importance of urban agricultural practices in Yaoundé, plants must be well washed and properly cooked before consumption in order to avoid a health risk that is limited to the spread of this waterborne pathogen in this metropoly.Keywords: Cyst, flagellated protozoa, wetland agricultural, dregs and urban zon

Probing the interface in a human co-chaperonin heptamer: residues disrupting oligomeric unfolded state identified

BACKGROUND: The co-chaperonin protein 10 (cpn10) assists cpn60 in the folding of nonnative polypeptides in a wide range of organisms. All known cpn10 molecules are heptamers of seven identical subunits that are linked together by β-strand interactions at a large and flexible interface. Unfolding of human mitochondrial cpn10 in urea results in an unfolded heptameric state whereas GuHCl additions result in unfolded monomers. To address the role of specific interface residues in the assembly of cpn10 we prepared two point-mutated variants, in each case removing a hydrophobic residue positioned at the subunit-subunit interface. RESULTS: Replacing valine-100 with a glycine (Val100Gly cpn10) results in a wild-type-like protein with seven-fold symmetry although the thermodynamic stability is decreased and the unfolding processes in urea and GuHCl both result in unfolded monomers. In sharp contrast, replacing phenylalanine-8 with a glycine (Phe8Gly cpn10) results in a protein that has lost the ability to assemble. Instead, this protein exists mostly as unfolded monomers. CONCLUSIONS: We conclude that valine-100 is a residue important to adopt an oligomeric unfolded state but it does not affect the ability to assemble in the folded state. In contrast, phenylalanine-8 is required for both heptamer assembly and monomer folding and therefore this mutation results in unfolded monomers at physiological conditions. Despite the plasticity and large size of the cpn10 interface, our observations show that isolated interface residues can be crucial for both the retention of a heptameric unfolded structure and for subunit folding

Safety and efficacy of a 6-month home-based exercise program in patients with facioscapulohumeral muscular dystrophy

Background: Previous randomized controlled trials investigating exercise training programs in facioscapulohumeral muscular dystrophy (FSHD) patients are scarce and of short duration only. This study assessed the safety and efficacy of a 6-month home-based exercise training program on fitness, muscle, and motor function in FSHD patients. Methods: Sixteen FSHD patients were randomly assigned to training (TG) and control (CG) groups (both n = 8) in a home-based exercise intervention. Training consisted of cycling 3 times weekly for 35 minutes (combination of strength, high-intensity interval, and low-intensity aerobic) at home for 24 weeks. Patients in CG also performed an identical training program (CTG) after 24 weeks. The primary outcome was change in peak oxygen uptake (VO 2 peak) measured every 6 weeks. The principal secondary outcomes were maximal quadriceps strength (MVC) and local quadriceps endurance every 12 weeks. Other outcome measures included maximal aerobic power (MAP) and experienced fatigue every 6 weeks, 6-minute walking distance every 12 weeks, and muscle characteristics from vastus lateralis biopsies taken pre- and postintervention. Results: The compliance rate was 91% in TG. Significant improvements with training were observed in the VO 2 peak (+19%, P = 0.002) and MAP by week 6 and further to week 24. Muscle endurance, MVC, and 6-minute walking distance increased and experienced fatigue decreased. Muscle fiber cross-sectional area and citrate synthase activity increased by 34% (P = 0.008) and 46% (P = 0.003), respectively. Dystrophic pathophysiologic patterns were not exacerbated. Similar improvements were experienced by TG and CTG. Conclusions: A combined strength and interval cycling exercise-training program compatible with patients' daily professional and social activities leads to significant functional benefits without compromising muscle tissue

The Current States, Challenges, Ongoing Efforts, and Future Perspectives of Pharmaceutical Excipients in Pediatric Patients in Each Country and Region

A major hurdle in pediatric formulation development is the lack of safety and toxicity data on some of the commonly used excipients. While the maximum oral safe dose for several kinds of excipients is known in the adult population, the doses in pediatric patients, including preterm neonates, are not established yet due to the lack of evidence-based data. This paper consists of four parts: (1) country-specific perspectives in different parts of the world (current state, challenges in excipients, and ongoing efforts) for ensuring the use of safe excipients, (2) comparing and contrasting the country-specific perspectives, (3) past and ongoing collaborative efforts, and (4) future perspectives on excipients for pediatric formulation. The regulatory process for pharmaceutical excipients has been developed. However, there are gaps between each region where a lack of information and an insufficient regulation process was found. Ongoing efforts include raising issues on excipient exposure, building a region-specific database, and improving excipient regulation; however, there is a lack of evidence-based information on safety for the pediatric population. More progress on clear safety limits, quantitative information on excipients of concern in the pediatric population, and international harmonization of excipients’ regulatory processes for the pediatric population are required

Contrasting nitrogen fluxes in African tropical forests of the Congo Basin

The observation of high losses of bioavailable nitrogen (N) and N richness in tropical forests is paradoxical with an apparent lack of N input. Hence, the current concept asserts that biological nitrogen fixation (BNF) must be a major N input for tropical forests. However, well-characterized N cycles are rare and geographically biased; organic N compounds are often neglected and soil gross N cycling is not well quantified. We conducted comprehensive N input and output measurements in four tropical forest types of the Congo Basin with contrasting biotic (mycorrhizal association) and abiotic (lowland-highland) environments. In 12 standardized setups, we monitored N deposition, throughfall, litterfall, leaching, and export during one hydrological year and completed this empirical N budget with nitrous oxide (N2O) flux measurement campaigns in both wet and dry season and in situ gross soil N transformations using N-15-tracing and numerical modeling. We found that all forests showed a very tight soil N cycle, with gross mineralization to immobilization ratios (M/I) close to 1 and relatively low gross nitrification to mineralization ratios (N/M). This was in line with the observation of dissolved organic nitrogen (DON) dominating N losses for the most abundant, arbuscular mycorrhizal associated, lowland forest type, but in contrast with high losses of dissolved inorganic nitrogen (DIN) in all other forest types. Altogether, our observations show that different forest types in central Africa exhibit N fluxes of contrasting magnitudes and N-species composition. In contrast to many Neotropical forests, our estimated N budgets of central African forests are imbalanced by a higher N input than output, with organic N contributing significantly to the input-output balance. This suggests that important other losses that are unaccounted for (e.g., NOx and N-2 as well as particulate N) might play a major role in the N cycle of mature African tropical forests