Using transect sampling to determine the distribution of some key non-timber forest products across habitat types near Boumba-Bek National Park, South-east Cameroon

Abstract Background Understanding the variation in distribution and abundance of non-timber forest products (NTFP) species is a crucial step in achieving their conservation and sustainable use. At the northern periphery of the Boumba-Bek National Park in Southeast Cameroon, little is known about which habitat type contain the highest abundance of NTFP species. In this study, we assessed habitat diversity and variation in the abundance of eight priority NTFP species comprising: Afrostyrax lepidophyllus, Baillonella toxisperma, Irvingia gabonensis, Panda oleosa, Pentaclethra macrophylla, Ricinodendron heudelotii, Scorodophloeus zenkeri and Tetrapleura tetraptera. The inventory was done along 16 linear transects of 5000 m × 20 m, and all the individuals, from juveniles (DBH  5 cm) of the eight NTFPs were recorded. Habitat types were characterized along transects following basic forest classification system used in ecology and then measured. Results In total, 13 different habitat types were identified with young secondary forests and periodically flooded forests representing 32.70% and 26.31% respectively. The least represented habitat was young fallows with Chromolaena odorata (0.08%). Seven NTFPs (A. lepidophyllus, B. toxisperma, I. gabonensis, P. oleosa, P. macrophylla, R. heudelotii and T. tetraptera) were predominantly represented in young secondary forests whereas S. zenkeri was more abundant in young Marantaceae secondary forests. The different types of young secondary forests identified seem to be favourable for the growth of the eight NTFPs. Conclusions This study demonstrated that habitat fragmentation driven by human activities such as industrial logging and shifting cultivation destroy the forest ecosystems and has a strong influence on the sustainability of the major NTFPs in the locality

Age-related changes in the mitochondrial proteome of the fungus Podospora anserina analyzed by 2D-DIGE and LC-MS/MS

Item does not contain fulltextMany questions concerning the molecular processes during biological aging remain unanswered. Since mitochondria are central players in aging, we applied quantitative two-dimensional difference gel electrophoresis (2D-DIGE) coupled to protein identification by mass spectrometry to study the age-dependent changes in the mitochondrial proteome of the fungus Podospora anserina - a well-established aging model. 67 gel spots exhibited significant, but remarkably moderate intensity changes. While typically the observed changes in protein abundance occurred progressively with age, for several proteins a pronounced change was observed at late age, sometimes inverting the trend observed at younger age. The identified proteins were assigned to a wide range of metabolic pathways including several implicated previously in biological aging. An overall decrease for subunits of complexes I and V of oxidative phosphorylation was confirmed by Western blot analysis and blue-native electrophoresis. Changes in several groups of proteins suggested a general increase in protein biosynthesis possibly reflecting a compensatory mechanism for increased quality control-related protein degradation at later age. Age-related augmentation in abundance of proteins involved in biosynthesis, folding, and protein degradation pathways sustain these observations. Furthermore, a significant decrease of two enzymes involved in the degradation of gamma-aminobutyrate (GABA) supported its previously suggested involvement in biological aging. BIOLOGICAL SIGNIFICANCE: We have followed the time course of changes in protein abundance during aging of the fungus P. anserina. The observed moderate but significant changes provide insight into the molecular adaptations to biological aging and highlight the metabolic pathways involved, thereby offering new leads for future research

Biological versus chemical control of fall armyworm and Lepidoptera stem borers of maize (Zea mays)

Insect pests are serious constraints to production of maize. There is little information on the control measures against those insects in Cameroon. This study was carried out to identify the different species of fall armyworm and stem borers of maize and test the efficacy of different control methods. The maize variety ATP (Acid Tolerant Population) was used in a randomized complete block design. Synthetic insecticides, lambda cyalothrine and cypermethrin, were applied at one and two weeks intervals at the recommended doses of 2 L/ha and 1.5 l/ha respectively. Bio insecticides: Neem oil (Azadirachta indica), and aqueous extracts of Chenopodium ambrosioides leaves were applied weekly at the doses of 1.40 L/ha and 6.80 L/ha respectively. The different larvae recorded were the fall armyworm (Spodoptera frugiperda) and stem borers (Busseola fusca and Sesamia calamistis). All the treatments used in this study had significant effects on the number of pupae, the tunnels and the number of perforations on stems of the maize. The Neem oil at one-week interval was more effective in reducing the incidence (81, 21%) and severity (61, 54%) at 76 Days After Planting of the attack by the caterpillars as well as on the number of larvae (14, 82%) throughout the trial

In-situ TEM observation of the response of ultrafine- and nanocrystalline-grained tungsten to extreme irradiation environments

The accumulation of defects, and in particular He bubbles, can have significant implications for the performance of materials exposed to the plasma in magnetic-confinement nuclear fusion reactors. Some of the most promising candidates for deployment into such environments are nanocrystalline materials as the engineering of grain boundary density offers the possibility of tailoring their radiation resistance properties. In order to investigate the microstructural evolution of ultrafine- and nanocrystalline-grained tungsten under conditions similar to those in a reactor, a transmission electron microscopy study with in He1 ion irradiation at 9506C has been completed. A dynamic and complex evolution in the microstructure situ 2 keV was observed including the formation of defect clusters, dislocations and bubbles. Nanocrystalline grains with dimensions less than around 60 nm demonstrated lower bubble density and greater bubble size than larger nanocrystalline (60–100 nm) and ultrafine (100–500 nm) grains. In grains over 100 nm, uniform distributions of bubbles and defects were formed. At higher fluences, large faceted bubbles were observed on the grain boundaries, especially on those of nanocrystalline grains, indicating the important role grain boundaries can play in trapping He and thus in giving rise to the enhanced radiation tolerance of nanocrystalline materials

A comparison between olive oil and exyta-virgin olive oil used as covering liquids in canned dried tomatoes:: hydrolytic and oxidative degradation durino storage

The hydrolytic and oxidative degradation of olive oil and extra-virgin olive oil, used as covering liquids in canned dried tomatoes, was studied during storage by means of conventional (acidity, peroxide value, p-anisidine value) and non conventional (polar compounds) analyses. The effects of the addition of spices were also considered. The hydrolysis and oxidation of olive oil increased faster and was higher than that of extravirgin olive oil in terms of absolute values but some other indices, such as percentage of oligopolymers and percentage of oxidized triglycerides, increased faster in extra-virgin olive oil than in olive oil. The antioxidant effect given by a higher concentration of polyphenols in the extra-virgin olive oil was shown by a reduced amount of secondary oxidation. However, olive oil and extra-virgin olive oils showed similar behaviour in terms of peroxide formation