Localization of an experimental ecological unit in the Maradi region of Nigeria

A detailed topographical and geomorphological description of a specific ecological unit in the Maradi region of the Sahel in the Niger Republic is presented. Sandy structures are classified into active dunes and covered dunes and an extensives vocabulary is developed to describe sub-categories. The descriptions are based on meteorological data (anemometric and rainfall) from local weather stations, ground observations, aerial photographs and LANDSAT pictures. The problem of dune reactivation and desertification is discussed both from the standpoint of causes and possible counter measures

Enhancing the photo-corrosion resistance of ZnO nanowire photocatalysts

Zinc oxide (ZnO) displays superior properties as a photocatalyst, compared to the more widely used TiO2. However, widespread application of ZnO is hampered by its high photo-corrosion in aqueous environments under UV irradiation. A systematic investigation of the effect of (i) post-production annealing, (ii) dissolved oxygen levels during photocatalysis and (iii) reactor configuration on the stability and photocatalytic activity (PCA) of ZnO nanowires, grown on either flat or circular supports, was conducted. Results show, for the first time, that it is possible to significantly enhance the photo-corrosion resistance of ZnO in water under UV irradiation while also increasing PCA. Oxygen plasma post-annealing of ZnO nanowire films led to a 46% higher photocatalytic degradation of phenol compared to as-produced films. In oxygen-saturated solutions, both thermally and oxygen plasma annealed ZnO revealed similar photo-corrosion resistance. Switching from a batch to a flow-through reactor, tripled phenol photodegradation under the same irradiation conditions from 19 to 57% due to enhanced mass transfer, while significantly increasing the stability and re-usability of the ZnO, with 5 repeat uses over 3 days showing no decrease in PCA. These results pave the way to more widespread use of photo-corrosion resistant ZnO in the degradation of organic pollutants in water.</p

Metabolic dysfunction following weight cycling in male mice

Background: Combatting over-weight or obesity can lead to large fluctuations in an individual‟s body weight, often referred to as weight cycling or “yo-yo” dieting. Current evidence regarding the potentially damaging effects of these changes is conflicting. Methods: Here, we assess the metabolic effects of weight cycling in a murine model, comprising three dietary switches to normal or high fat diets at 6 week intervals; male C57BL/6 mice were fed either a control (C) or high fat (F) diet for 6 weeks (n=140/group). C and F groups were then either maintained on their initial diet (CC and FF respectively) or switched to a high fat (CF) or control (FC) diet (n=35/group). For the final 6 week interval, CC and CF groups were returned to the control diet (CCC and CFC groups) while FC and FF groups were placed on a high fat diet (FCF and FFF) (n=28/group). Results: For the majority of metabolic outcomes changes aligned with dietary switches; however assessment of neuropeptides and receptors involved in appetite regulation and reward signalling pathways reveal variable patterns of expression. Furthermore, we demonstrate that multiple cycling events leads to a significant increase in internal fat deposition, even when compared to animals maintained on a high fat diet (Internal Fat: FCF: 7.4 ± 0.2g vs. FFF: 5.6 ± 0.2g; p<0.01). Conclusions: Increased internal adipose tissue is strongly linked to the development of metabolic syndrome associated conditions such as type 2 diabetes, cardiovascular disease and hypertension. While further work will be required to elucidate the mechanisms underlying the neuronal control of energy homeostasis, these studies provide a causative link between weight cycling and adverse health

Exercise Attenuates CTGF Levels, Delaying the Onset of Fibrosis in the Aging Left Ventricle

Aging is associated with a progressive increase in collagen (i.e., fibrosis) in the aging heart. Fibrosis is associated with a stiffening of the heart and a decrease in heart function. Previous data (Kwak, 2008) showed that matrix metalloproteinase (MMP) activity in the aging heart is decreased linked to an elevation TIMP-1 (tissue inhibitor of MMPs-1); while exercise training increased TIMP-1 and reduced MMP expression. Connective tissue growth factor (CTGF) is an upstream inhibitor of TIMP-1 and is implicated in diabetes and heart failure. We hypothesized that exercise would decrease CTGF levels, thus reducing fibrosis in the aged left ventricle. Young (3 months) and old (31 months) male Fischer 344 × Brown Norway F1 hybrid (F344BNF1) rats were used for the study. The rats were randomly assigned to one of the following experimental groups (n=10/group): young sedentary controls (YS), young exercise trained (YE), old sedentary controls (OS), and old exercise trained (OE). Rats walked quickly on a motor-driven treadmill for 45 min/day, 5 days/wk, for 12 wks. Heart levels of CTGF were determined via Immunohistochemistry (IHC). CTGF was expressed more in the old group compared to the young group, as well as the sedentary group compared to the exercise group. Future studies will determine if CTGF is downstream of angiotensin II, TGF-beta, and oxidative stress in regulating MMPs and TIMP-1

The effects of exercise on caspase-independent mitochondrial proteins in regards to age-related apoptosis

Exercise may have protective factors in reducing oxidative stress, mitochondrial dysfunction and mitochondrial caspase-dependent apoptosis with aging. It is presently unclear whether the caspase-independent apoptosis via EndonucleaseG (EndoG) and Apoptosis Inducing Factor (AIF) translocation from the mitochondria to the nucleosome is effected by exercise in aging skeletal muscle. It is understood that in aging skeletal muscle EndoG and AIF do translocate from the mitochondria to the nucleosome. We hypothesize that exercise will attenuate the translocation of EndoG and AIF from the mitochondria to the nucleosome in aging white gastrocnemius muscle. Twenty-four Fischer Brown Norway rats were randomly assigned to four groups, young sedentary, old sedentary, young exercisers and old exercisers. The exercise consisted of treadmill training. The protein expression of EndoG and AIF were analyzed using western blot assays. In the old sedentary group, EndoG increased 86.4 % in the soluble fraction, but there was no change in the young groups. EndoG protein levels in the nucleosome fraction of young exercisers decreased 49 % when compared to young sedentary controls and old sedentary increased by 86.5 % when compared to young sedentary controls. With AIF changes in the soluble fraction were neglible. Protein levels of AIF in the nucleosome fraction increased 64 % in the old sedentary group compared to young sedentary controls. The data indicates that exercise was a protective factor against caspase-independent apoptosis by decreasing the translocation of EndoG and AIF to the nucleosome in aged skeletal muscle

Comparative study of the effect of long-term ageing on the behaviour of bitumen and mastics with mineral fillers

This paper is based on a part of the research project carried out at the request of the German Research Foundation (DFG), under research project No. WE 1642/1-2 and LE 3649/1-2 (FOR2089).This study aims to evaluate the effect of mineral fillers on bitumen ageing. Two different bitumens and four mastics were investigated in the unaged and long-term aged states, based on different properties (consistency, rheology, fatigue resistance and ductility). Mastics stiffened less due to ageing treatment than bitumens, especially with granite filler. However, the results of the performance tests were not definitive regarding the effect of the filler. Aged bitumen showed greater fatigue resistance and higher specific energy of ductile fracture than unaged bitumen, whereas the mastics showed minor variations in the specific energy of ductile fracture with ageing treatment, which is indicative of less ageing, but the fatigue resistance decreased significantly in mastics with one of the bitumens.authorsversionpublishe

Bilateral symmetrical cortical osteolytic lesions in two patients with Gaucher disease

Gaucher disease (GD) is an autosomal recessive lysosomal storage disorder characterized by the reduced or absent activity of glucocerebrosidase. The disease is split into three types. Type 3, or chronic neuronopathic GD, manifests with heterogeneous clinical presentations. Skeletal manifestations of GD can include abnormal bone remodeling resulting in the characteristic Erlenmeyer flask deformities, painful bone crises, osteopenia, and an increased frequency of fractures. Osteolytic lesions can also occur but are rare and tend to be large, expanding intramedullary lesions with cortical thinning. We present two adolescent patients with type 3 GD who developed bilateral symmetrical cortical osteolytic lesions. The lesions in both cases demonstrate predominant cortical scalloping with fairly indolent growth. Neither patient manifests some of the more common bony manifestations of GD—bone crises or osteonecrosis. These atypical and unique skeletal findings in two unrelated probands with type 3 GD further expand the extent of phenotypic variation encountered in this single gene disorder