Urbanisation lowers great tit Parus major breeding success at multiple spatial scales

While numerous studies have reported negative effects of urbanisation on birds, few have examined the role of urban scale in influencing breeding success. Furthermore, many studies have relied on qualitative rather than quantitative assessments of urbanisation. This study sought to address these issues by testing the effects of urbanisation, measured at two spatial scales, on the breeding success of great tits Parus major. A nested study design, incorporating over 400 nestboxes, was used in study sites across northern Belgium with a priori quantified degrees of urbanisation at both local and regional scales. All measured breeding parameters were found to vary at one or both spatial scales of urbanisation; in more urbanised areas great tits displayed advanced laying dates but lower breeding success compared to rural areas, with smaller clutch sizes, lower nestling masses and fewer fledglings per egg. Importantly, urbanisation effects were not limited to big cities as birds breeding in gardens or parks in small towns also had comparatively low success. We found that both regional- and local-scale urbanisation had consistent significant effects on laying date, clutch size and nestling mass, while the number of fledglings per egg was negatively influenced by local-scale urbanisation only. Results of this study therefore highlight the importance of utilising multiple spatial scales in analysing urbanisation effects, as well as the potential negative impact of local urbanisation on breeding success. This calls for further investigation into mechanisms driving urbanisation effects and how these may vary at different scales

A scan of rural civil society

PLAAS commissioned Phuhlisani to undertake a review of rural civil society, to explore innovative ways in which researchers and organisations in rural civil society can work together in linking research to policy engagement from ‘below’. PLAAS, being a research institute, is interested in how research can best empower rural civil society organisations (CSOs) in their dealings with government and other role players, and how to strengthen the democratic policy process. This review seeks new information that goes beyond the usual discussions of rural civil society to help inform fresh-thinking and a deeper understanding of the strategic issues involved in relations between poor, marginalised rural people, their organisations, and organs of the state

Adaptation to protein deficiency: cortisol, thyroxine, insulin and glucose in young pigs

No Abstrac

Strategies to support South African smallholders as a contribution to government’s second economy strategy. Volume 1: Situation analysis, fieldwork findings and main conclusions

Within the ambit of the Accelerated and Shared Growth Initiative of South Africa, government is leading a process to define a Second Economy Strategy, and has identified the agricultural sector as a site of opportunity, potentially fostering a larger number of smallholder agriculturalists. In an effort to identify an implementable program to support the smallholder sector, this study closely analyses what makes particular South African smallholdings in various settings successful and what factors contributed to their success. A broad definition of agricultural smallholding is employed including independent operators, group farmers, subsistence farmers and commercial farmers. ‘Supporting the smallholder sector’ is conceptualised as consisting of four distinct strands, namely the prospects and measures for: improving the performance of subsistence-oriented smallholders; encouraging/enabling currently subsistence-oriented smallholders to benefit from a more commercial orientation; improving the performance of commercially oriented smallholders; and increasing participation in smallholder agriculture among those (especially rural dwellers) who do not practise agriculture

Nouveaux procédés verts d'oxydation de l'acide oléique

Dans un contexte de raréfaction des ressources pétrolières et de pressions environnementales, l industrie chimique a besoin d'innover en développant de nouvelles filières destinées à l'élaboration de bioproduits, à partir de matières premières d'origine végétale. Les acides gras insaturés obtenus à partir des huiles végétales, constituent ainsi une ressource renouvelable à fort potentiel permettant de diversifier les approvisionnements d'origine pétrolière. Notre intérêt s'est porté sur la réaction de scission oxydative d acides gras insaturés pour conduire à des monoacides et diacides à chaînes courtes et impaires, peu ou pas disponibles à l état naturel. Ce type de chaînes hydrocarbonées est recherché dans l industrie, car elles possèdent des propriétés spécifiques, mais elles ne sont actuellement produites qu'à partir de ressources fossiles. L'objectif était donc de mettre au point un procédé de clivage oxydatif performant, moins onéreux et moins polluant que l ozonolyse, le seul procédé industriel opérationnel. Les conditions oxydantes sélectionnées font appel à l eau oxygénée en tant qu oxydant, associée à un catalyseur de transfert de phase, sans avoir recours à un solvant organique. Plusieurs catalyseurs de transfert de phase Q3{PO4[WO(O2)2]4} ont été préparés à partir de l acide tungstophosphorique, d eau oxygénée et d'un sel d ammonium quaternaire (Q+,Cl-), afin de comparer leur efficacité à transférer l'oxygène vers le substrat en phase organique. Une optimisation des paramètres réactionnels a été effectuée avec le catalyseur le plus performant. De plus, deux protocoles ont été mis au point, pour la préparation in-situ du catalyseur et pour sa récupération en fin de réaction. Le procédé a été généralisé à des dérivés d acides gras dans le but d obtenir d'autres acides à chaînes courtes, répondant à une large gamme d'applications. Le gain environnemental lié à ce nouveau procédé a été évalué par le calcul d indicateurs verts. Afin d envisager un recyclage plus aisé du catalyseur, l anion oxodiperoxotungstate {PO4[WO(O2)2]4}3-, l espèce active du catalyseur, a été supporté sur des résines échangeuses d anions. Deux types de résines macroporeuses ont été testées : des résines commerciales (Amberlite IRA 900 et Lewatit K7367) et des résines modifiées (type Merrifield). Nous avons montré que ces dernières conduisent à de meilleurs rendements de scission oxydative de l acide oléique que les résines commerciales, et ce, malgré la présence de solvants. Cependant, l immobilisation de l anion oxodiperoxotungstate sur les résines commerciales a permis la synthèse en une seule étape d acétals, composés présentant un grand intérêt pour la synthèse de dérivés à haute valeur ajoutée. En utilisant l acétone, à la fois comme réactif et solvant, nous avons obtenu de bons rendements en cétal. De plus, la réaction d acétalisation one-pot de l acide oléique a pu être étendue à d autres solvants (alcools), offrant la possibilité de synthétiser un large panel d acétals. Le procédé développé est particulièrement intéressant car il conduit directement à la synthèse d acétals ou de cétals à partir d un acide gras insaturé biosourcé, en évitant les étapes de réactions intermédiaires.In a context of scarce oil resources and environmental pressures, the chemical industry needs to innovate by developing new production chains aiming the design of bioproducts from biobased raw materials. Unsaturated fatty acids derived from vegetable oils, thus represents renewable resources with a great potential, allowing to diversify petroleum based supplies. Our interest is focused on the oxidative cleavage reaction of unsaturated fatty acids to yield mono-acids and di-acids with shorter and odd hydrocarbon chains, which are not available at a natural state. Such hydrocarbon chains are attractive for industry because they meet specific properties. But, they are currently only produced from fossil resources. Therefore, the objective was to develop an efficient method for oxidative cleavage, less expensive and less polluting than ozonolysis, the only operational industrial process. The selected oxidizing conditions employs hydrogen peroxide as oxidant, together with a phase transfer catalyst, without using an organic solvent. Several phase transfer catalysts Q3{PO4[WO(O2)2]4} were prepared from tungstophosphoric acid, hydrogen peroxide and a quaternary ammonium salt (Q+,Cl-), in order to compare their effectiveness in transferring oxygen to the substrate in the organic phase. An optimization of reaction parameters was carried out with the most performing catalyst. In addition, two protocols have been developed for the in-situ preparation of the catalyst and its recovery after reaction. The method was extended to fatty acids derivatives, in order to obtain other short chain acids, having a wide range of applications. The environmental benefits associated with this new method were evaluated by calculating green indicators. To consider an easier recycling of the catalyst, the oxodiperoxotungstate anion {PO4[WO(O2)2]4}3-, the active species of the catalyst was supported on anion-exchange resins. Two types of macroporous resins were tested: commercial resins (Amberlite IRA 900 and Lewatit K7367) and modified resins (type Merrifield). We showed that the modified resins, lead to the oxidative cleavage of oleic acid with higher yields than commercial ones, despite the presence of solvent. However, the immobilisation of the oxodiperoxtungstate anion on commercial resins allows the one-step synthesis of acetals, compounds of great interest for the synthesis of derivatives with a high added value. Using acetone as both reagent and solvent, we obtained good yields in ketal. Furthermore, the "one-pot" acetalization reaction of oleic acid was extended to other solvents (alcohols) as an opportunity to synthesize a wide range of acetals. The developed process is particularly interesting as it leads to the direct synthesis of ketal or acetals from an unsaturated fatty acid, avoiding the intermediate reaction stepsTOULOUSE-INP (315552154) / SudocSudocFranceF

Conception de biosolvants à partir de la molécule plateforme furfural, en laboratoires virtuel et réel

TOULOUSE-INP (315552154) / SudocSudocFranceF

Cardiac tumours in children

Cardiac tumours are benign or malignant neoplasms arising primarily in the inner lining, muscle layer, or the surrounding pericardium of the heart. They can be primary or metastatic. Primary cardiac tumours are rare in paediatric practice with a prevalence of 0.0017 to 0.28 in autopsy series. In contrast, the incidence of cardiac tumours during foetal life has been reported to be approximately 0.14%. The vast majority of primary cardiac tumours in children are benign, whilst approximately 10% are malignant. Secondary malignant tumours are 10–20 times more prevalent than primary malignant tumours. Rhabdomyoma is the most common cardiac tumour during foetal life and childhood. It accounts for more than 60% of all primary cardiac tumours. The frequency and type of cardiac tumours in adults differ from those in children with 75% being benign and 25% being malignant. Myxomas are the most common primary tumours in adults constituting 40% of benign tumours. Sarcomas make up 75% of malignant cardiac masses. Echocardiography, Computing Tomography (CT) and Magnetic Resonance Imaging (MRI) of the heart are the main non-invasive diagnostic tools. Cardiac catheterisation is seldom necessary. Tumour biopsy with histological assessment remains the gold standard for confirmation of the diagnosis. Surgical resection of primary cardiac tumours should be considered to relieve symptoms and mechanical obstruction to blood flow. The outcome of surgical resection in symptomatic, non-myxomatous benign cardiac tumours is favourable. Patients with primary cardiac malignancies may benefit from palliative surgery but this approach should not be recommended for patients with metastatic cardiac tumours. Surgery, chemotherapy and radiotherapy may prolong survival. The prognosis for malignant primary cardiac tumours is generally extremely poor

Aneuploidy and chromosomal instability in cancer: a jackpot to chaos

Genomic instability (GIN) is a hallmark of cancer cells that facilitates the acquisition of mutations conferring aggressive or drug-resistant phenotypes during cancer evolution. Chromosomal instability (CIN) is a form of GIN that involves frequent cytogenetic changes leading to changes in chromosome copy number (aneuploidy). While both CIN and aneuploidy are common characteristics of cancer cells, their roles in tumor initiation and progression are unclear. On the one hand, CIN and aneuploidy are known to provide genetic variation to allow cells to adapt in changing environments such as nutrient fluctuations and hypoxia. Patients with constitutive aneuploidies are more susceptible to certain types of cancers, suggesting that changes in chromosome copy number could positively contribute to cancer evolution. On the other hand, chromosomal imbalances have been observed to have detrimental effects on cellular fitness and might trigger cell cycle arrest or apoptosis. Furthermore, mouse models for CIN have led to conflicting results. Taken together these findings suggest that the relationship between CIN, aneuploidy and cancer is more complex than what was previously anticipated. Here we review what is known about this complex ménage à trois, discuss recent evidence suggesting that aneuploidy, CIN and GIN together promote a vicious cycle of genome chaos. Lastly, we propose a working hypothesis to reconcile the conflicting observations regarding the role of aneuploidy and CIN in tumorigenesis