Determining specific biomass activity in anaerobic wastewater treatment processes

«Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)»An experimental method for the measurement of specific gas production rate was developed and tested with biomass samples taken from anaerobic fluidized bed reactors, operating with a variety of carriers with molasses, condensate from cellulose production and brewery wastewater as feeds. The method is based on reactor sampling and offline gas volume measurement during a known time interval. Important factors are biomass and liquid sampling under oxygen-free conditions, using the liquid from the reactor as substrate, providing sufficient mixing and maintaining the physical integrity of the biomass. The method was developed in such a way that small samples (20 ml) were taken under anaerobic conditions (poising agent) for short-term (2-3 min.) gas rate measurements in a small fluidized bed (25 ml) batch reactor with U-tube. Biomass content was measured by an instrumental nitrogen method (Dumas), followed by weight determination of the carrier. The gas rates measured with the test system, and their dependence on substrate concentration, were in good agreement with those directly measured from the continuous fluidized bed reactor. Additions of molasses and acetate to the sample proved that the influence of concentration on the biomass activity can be obtained only by operating the continuous reactor at the concentration levels of interest. Comparison between the reactors showed large differences in the specific activity and the total reactor activity. It was found when comparing two reactors, that the values of the specific and the total activities permitted the calculation of the relative biomass quantities. In this way the influence of the carrier-type could be evaluated

Possible Vertical Transmission of Bartonella bacilliformis in Peru

A 22-day-old male was admitted with a 2-day history of irritability, dyspnea, jaundice, fever, and gastrointestinal bleeding. A thin blood smear was performed, which showed the presence of intraerythrocyte bacteria identified as Bartonella bacilliformis, and subsequently, the child was diagnosed with Carrion's disease. The diagnosis was confirmed by specific polymerase chain reaction. The child was born in a non-endemic B. bacilliformis area and had not traveled to such an area before hospitalization. However, the mother was from an endemic B. bacilliformis area, and posterior physical examination showed the presence of a wart compatible with B. bacilliformis in semi-immune subjects. These data support vertical transmission of B. bacilliformis

Spatial niche expansion at multiple habitat scales of a tropical freshwater turtle in the absence of a potential competitor

Resource partitioning, the division of limited resources by species to help avoid competi-tion, has been observed in freshwater turtle assemblages in several natural systems but has rarely been studied in tropical African ecosystems. Here, we investigate habitat preferences of two conge-neric species in the family Pelomedusidae, Pelusios castaneus and P. cupulatta, in riverine/wetland habitats in the southern Ivory Coast (West Africa). Pelusios castaneus is a widespread species across West-central African savannahs and open forests, whereas P. cupulatta is endemic to the Upper Guinean forest region in West Africa. The two species have a similar diet composition (mainly car-nivorous) but diverge considerably in body size, P. cupulatta being much larger. We use hand-fish-ing-nets and fishing funnel traps to record turtles in 18 distinct sites and analyze habitat preferences by species at two spatial scales. At a macro-habitat scale, P. castaneus is captured mainly in marsh-lands, whereas P. cupulatta is found in both rivers and wetlands. The two species differ significantly in their use of: (i) banks (P. castaneus being found primarily in spots with grassy banks, whereas P. cupulatta is found in spots with forested banks), and (ii) aquatic vegetation (P. cupulatta prefers spots with more abundant aquatic vegetation than P. castaneus), but both species select sites with no or moderate current. Additionally, in sites where P. cupulatta is not found, P. castaneus expands its spatial niche at multiple habitat scales, notably invading waterbodies with forested banks. Our results suggest that these two Pelomedusid turtle species potentially compete in the freshwater habitats in the southern Ivory Coast

Testing hypotheses of habitat use and temporal activity in relation to body plan in a mediterranean lizard community

A body plan (bauplan) is a suite of morphological characters shared by phylogenetically related animals at some point during their development. Despite its value, the bauplan concept is still rarely employed to characterize functional groups in community ecology. Here, we examine habitat use and spatio-temporal activity correlates of an entire sevenspecies community of lizards with different bauplans. The study was carried out in three locations in central Italy, encompassing a complex landscape with a patchy mosaic of a wide variety of habitats and microclimates. We tested four hypotheses regarding niche breadth, habitat use, and activity patterns. The first hypothesis, niche complementarity, in which species with similar body shapes should non-randomly partition available habitats, was not supported. By contrast, the hypotheses that larger bodied species should have a wider niche breadth, that slower species should inhabit habitat types of higher cover, and species inhabiting open sunny habitats should exhibit more seasonally variable activity patterns, were all supported by the data. Sympatric lizard communities in our study area were clearly organized by autecological constraints and eco-physiological attributes

α-Synuclein Aggregated with Tau and β-Amyloid in Human Platelets from Healthy Subjects: Correlation with Physical Exercise

The loss of protein homeostasis that has been associated with aging leads to altered levels and conformational instability of proteins, which tend to form toxic aggregates. In particular, brain aging presents characteristic patterns of misfolded oligomers, primarily constituted of β-amyloid (Aβ), tau, and α-synuclein (α-syn), which can accumulate in neuronal membranes or extracellular compartments. Such aging-related proteins can also reach peripheral compartments, thus suggesting the possibility to monitor their accumulation in more accessible fluids. In this respect, we have demonstrated that α-syn forms detectable hetero-aggregates with Aβ or tau in red blood cells (RBCs) of healthy subjects. In particular, α-syn levels and its heteromeric interactions are modulated by plasma antioxidant capability (AOC), which increases in turn with physical activity. In order to understand if a specific distribution of misfolded proteins can occur in other blood cells, a cohort of human subjects was enrolled to establish a correlation among AOC, the level of physical exercise and the concentrations of aging-related proteins in platelets. The healthy subjects were divided depending on their level of physical exercise (i.e., athletes and sedentary subjects) and their age (young and older subjects). Herein, aging-related proteins (i.e., α-syn, tau and Aβ) were confirmed to be present in human platelets. Among such proteins, platelet tau concentration was demonstrated to decrease in athletes, while α-syn and Aβ did not correlate with physical exercise. For the first time, α-syn was shown to directly interact with Aβ and tau in platelets, forming detectable hetero-complexes. Interestingly, α-syn interaction with tau was inversely related to plasma AOC and to the level of physical activity. These results suggested that α-syn heterocomplexes, particularly with tau, could represent novel indicators to monitor aging-related proteins in platelets

Long-term changes in population size and the age-structure and sex-ratio of Waterbuck in a Sudanian savannah of Burkina Faso

The waterbuck (Kobus ellipsiprymnus), though widespread throughout Africa, is suspected to be declining overall. Data on population numbers and structure are lacking for many parts of its range, especially in West Africa, where the subspecies defassa is found. The aim of the present study was to evaluate the abundance, distribution and attributes of waterbuck populations in the Nazinga Forest Reserve, southern Burkina Faso. We investigated waterbuck population trends in the park using transect data collected in 1985-2019. For the more detailed analyses of population structure and distribution of the animals we used census data gathered during 2019. Most animals were adults (46.6%), and the sex ratio was heavily skewed towards females (5:1). Most animals were concentrated along the larger rivers. There was no influence of poacher activity on waterbuck distribution. In the long term (1985-2019), the population dynamics of waterbuck can be roughly divided into two main periods: a phase of population increase from 1985 to 2005, and one of ongoing population collapse from 2007-2019 Although the declining population trend was obvious, coefficients of determination were low indicating that the years explained poorly the number of individuals and the number of sightings obtained. Waterbuck numbers in the Nazinga Forest Reserve are declining, but we found no single reason to explain this trend. It is likely that a combination of factors, including global warming (increased aridity) and illegal activities such as poaching, are responsible. Because there are probably multiple reasons for the observed waterbuck population decline in our study area, we suggest that a multifaceted approach should be adopted in order to enhance the conservation status of the local waterbuck populations

Effets de la densité des compétiteurs et du régime des pluies sur la dynamique de population à long terme d’une communauté d’herbivores dans une savane ouest-africaine

En dépit de beaucoup d’articles scientifiques consacrés à l’écologie des communautés des ongulés dans les savanes africaines, seules quelques études se sont focalisées sur l’Afrique de l’Ouest. Dans cet article, sur la base de line-transects sur le long terme (1985-2008), nous analysons les interactions entre les espèces d’ongulés de savane dans le Ranch de Gibier de Nazinga (Burkina Faso) en relation avec les pluies et la densité de leurs compétiteurs potentiels. Nous avons estimé la taille des populations de toutes les espèces par comptage à distance. Il n’est pas apparu d’effet année sur la taille des populations pour toutes les espèces mais, en analysant par groupes de cinq années, des fluctuations significatives ont été décelées au moins pour certaines espèces. Des modèles linéaires généralisés sur les relations interspécifiques (tant positives que négatives) entre paires d’espèces suggèrent que les fluctuations interannuelles de la taille des populations des divers ongulés seraient vraisemblablement imputables aux variations de l’intensité du braconnage, à l’influence du régime des pluies (pour au moins trois espèces brouteuses) et à une densité-dépendance négative.Despite many scientific articles were devoted to study aspects of community ecology of ungulates in African savannahs, only very few studies focused on communities from Western Africa. In this paper, we analyse the interspecific interactions of savannah ungulates in the Nazinga Game Ranch (Burkina Faso) in relation to rainfall patterns and potential competitor density, using long-term (1985-2008) line-transect data. We estimated the population sizes of all species by using distance sampling. There was no effect of the year on the population sizes of all the species, but, when 5-year-period groups were analyzed, there were significant fluctuations over time intervals for at least some of the species. Generalized Linear Models on the interspecific relationships (either positive or negative) between pairs of species would suggest that interannual population size fluctuations of the various ungulates were likely attributable to fluctuations in poaching intensity, the influences of rainfall regimes (for at least three browser species), and negative density dependence

Age-stratified interview campaigns suggest ongoing decline of a threatened tortoise species in the West African Sahel

Face-to-face interviews with local populations are often used to determine the distribution and population trends of elusive threatened species. Although interviewee responses may suffer from some bias, historical trends in the status of a species can be investigated from age-structured questionnaires. In this paper, we tested this idea by analysing separately answers given by older (> 60 years age) and younger respondents (25-44 years old) on the status of the African spurred tortoise, (Centrochelys sulcata), a charismatic large reptile listed as Vulnerable in the IUCN Red List. We interviewed 619 persons (hunters/farmers/cattle farmers) of different ages in three of the species’ habitat countries (Burkina Faso, Niger and Nigeria). Interviewees were asked whether in their experience the tortoise was common, rare or absent. By using Generalized Linear Models we showed that the probability to answer “common” increased with age in Nigeria and Burkina Faso, whereas the probability of responding “absent” declined with age in Nigeria and Niger. There were no significant effects of age for the answer 'rare' in any country and no differences were found between villages in any of the studied countries. From our data we conclude that spurred tortoises have been extirpated in 16.7% of study sites. We argue that if statistical differences emerge between answers given by respondents of various age classes on the population status of a target species, it is possible to conclude that the species’ situation may have significantly changed during the last 30-40 years

Predicting the structure of turtle assemblages along a megatransect in West Africa

Understanding large- and small-scale patterns as well as the determinants of species richness is central for the study of evolutionary mechanisms. The extent to which species richness in local communities is related to larger scale processes is a pre-eminent topic in ecological and evolutionary research. To investigate how local and regional species richness are related, we sampled freshwater turtle assemblages in seven localities to represent the variation in ecological conditions along a 90km South-North megatransect in Benin, West Africa. In each locality, all turtles captured were identified and measured, and microhabitat classified in which individual turtles were observed. Based on these data we used community diversity metrics to compare turtle assemblages. Spatial autocorrelation did not affect our data. For all localities pooled, only two species (Pelusios castaneus and Pelomedusa olivacea) were the most common, and one species (Trionyx triunguis) the rarest. Analyses of the commonest and more numerous species showed that the abundance of P. castaneus declined with an increase in latitude and longitude, but the opposite was true for P. olivacea. We showed that various microhabitat characteristics were significantly correlated with the abundance of the two common species. We found significant but variable South-North gradients in microhabitat use for different turtle species. Our results highlight the importance of studying interactions between local environments, the ecological requirements of each species, and their synecological relationships

Nusinersen treatment and cerebrospinal fluid neurofilaments : An explorative study on Spinal Muscular Atrophy type 3 patients

The antisense oligonucleotide Nusinersen has been recently licensed to treat spinal muscular atrophy (SMA). Since SMA type 3 is characterized by variable phenotype and milder progression, biomarkers of early treatment response are urgently needed. We investigated the cerebrospinal fluid (CSF) concentration of neurofilaments in SMA type 3 patients treated with Nusinersen as a potential biomarker of treatment efficacy. The concentration of phosphorylated neurofilaments heavy chain (pNfH) and light chain (NfL) in the CSF of SMA type 3 patients was evaluated before and after six months since the first Nusinersen administration, performed with commercially available enzyme-linked immunosorbent assay (ELISA) kits. Clinical evaluation of SMA patients was performed with standardized motor function scales. Baseline neurofilament levels in patients were comparable to controls, but significantly decreased after six months of treatment, while motor functions were only marginally ameliorated. No significant correlation was observed between the change in motor functions and that of neurofilaments over time. The reduction of neurofilament levels suggests a possible early biochemical effect of treatment on axonal degeneration, which may precede changes in motor performance. Our study mandates further investigations to assess neurofilaments as a marker of treatment response