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This paper presents the theoretical, operational and implementation premises that guide the development research agenda of the Center of Development Research (ZEF), exemplified by three agroforestry-related case studies. First, the importance, assumptions, conditions and priorities for development research in the context of developing countries are reviewed. Second, the three core premises of ZEF's research approach, (1) transdisciplinary to carry out research on real-life problems, (2) symmetrical partnerships with local stakeholders to sustain ground activities and ensure implementation, and (3) capacity development to warrant future competences, are exposed. Third, these premises are exemplified and mirrored in three agroforestry-related case-studies: (1) slash-and-burn agriculture in the Brazilian Amazon, (2) socio-ecological management of coffee-agroforests in Ethiopia, and (3) afforestation with multipurpose tree species in Uzbekistan. The paper concludes by streamlining the theoretical and practical premises exposed with the presented case-studies, and confirming how these have guided ZEF in the planning, implementation and continuation of development research programs. Although ZEF's approach to development research is dynamic and continuously subject to assessment, its core remains guiding even after two decades of implementation, appearing to be a suitable pathway for reaching development objectives. [ABSTRACT FROM AUTHOR]

Four commercially available disinfection products were tested for their efficacy against Clavibacter michiganensis subsp. sepedonicus (Cms), causative agent of bacterial ring rot, on wooden potato storage crates. Each of these products represented a different class of biocide, i.e. organic acids (benzoic acid), peroxygenous compounds (potassium peroxysulfate), quaternary ammonium compounds (didecyldimethylammoniumchloride) and hypochlorite-generating compounds (sodium- p-toluenesulfochloramide). The target objects consisted of small wooden panels that were smeared with potato tuber pulp homogenized with a high inoculum of Cms. By dipping the inoculated panels into the product solutions and subsequent determination of the densities of colony-forming units, the relative efficacy of the products was established. The two products that exhibited the highest relative efficacy were studied for their disinfection performance when applied as cleaning agent in a conventional automated crate washer. The results showed that jet cleaning in a crate washer for 2 min using the authorised dose of the product containing sodium- p-toluenesulfochloramide is an effective method for disinfecting Cms-contaminated wooden potato crates. [ABSTRACT FROM AUTHOR]

Afforestation of degraded croplands by planting N-fixing trees in arid regions is highly recognized. However, fixation of atmospheric nitrogen gas (N) by woody perennials is often limited on phosphorus (P) poor soils, while any factor limiting N nutrition inhibits tree growth. In a two-factorial field experiment, the effect of three P amendments was examined during 2006-2008 on N fixation, biomass production, and foliage feed quality of actinorhizal Elaeagnus angustifolia L. and leguminous Robinia pseudoacacia L. With the N natural abundance method, N fixation was quantified based on foliar and whole-tree sampling against three non-N-fixing reference species: Gleditsia triacanthos L., Populus euphratica Oliv., and Ulmus pumila L. The P applications, in March 2006 and April 2007 only, included (i) high-P (90 kg P ha), (ii) low-P (45 kg P ha), and (iii) 0-P. After 3 years, the average proportion of N derived from atmosphere (Ndfa, %) increased from 78 % with 0-P to 87 % with high P when confounded over both N-fixing species. With the used density of 5,714 trees ha, the total amount of N fixed (Ndfa, kg N ha) with high-P increased from 64 kg N ha (year 1) to 807 kg N ha (year 3) in E. angustifolia and from 9 kg N ha (year 1) to 155 kg N ha (year 3) in R. pseudoacacia. Total above-ground biomass increases were too variable to be significant. Leaf N content and therewith also leaf crude protein content, which is an indicator for feed quality, increased significantly (24 %) with high-P when compared to 0-P for E. angustifolia. Overall findings indicated the suitability of the two N-fixing species for afforestating salt-affected croplands, low in soil P. With P-applications as low as 90 kg P ha, the production potential of E. angustifolia and R. pseudoacacia, including the supply of protein-rich feed, could be increased on salt-affected croplands. [ABSTRACT FROM AUTHOR]

fforestation with fast growing N-fixing trees is an option for ecological restoration of highly-salinized irrigated croplands, but information about the N-fixing capability of trees on saline soils is sparse. The N-enrichment technique (NET) and the A value (AV) method were used to quantify in lysimeters the proportion of atmospheric N (%Ndfa) fixed by Elaeagnus angustifolia L., with a reference to non-N-fixing Gleditsia triacanthos L. and Ulmus pumila L. Twenty kg N ha of 5 atom %N excess ammonium nitrate (35% N) was applied to 1-year-old trees in 2007 and 2-year-olds in 2008. Since this rate was insufficient for the older reference trees, 60 kg N ha was applied in 2008. With NET, the %Ndfa of E. angustifolia in 2007 was 79% when referenced against U. pumila and 68% against G. triacanthos. With the AV method, the %Ndfa of 2-year-old E. angustifolia was 80 and 68% when referenced against U. pumila and G. triacanthos, respectively. Over 2 years, E. angustifolia fixed 17 kg N ha when related to U. pumila and 14 kg N ha with G. triacanthos (assumed density: 5,000 trees ha). N-fixing E. angustifolia has the potential to be self-sufficient in N when planted in the strongly saline soils. [ABSTRACT FROM AUTHOR]

Afforestation is a prospective strategy to improve soil fertility of salt-affected, irrigated croplands in Central Asia. The effect of macro- and mesofauna and microflora on the decomposition of tree leaves, collected ca. 2 weeks before natural fall, was monitored during 367 days. The three-year-old tree plantations consisted of Elaeagnus angustifolia L., Ulmus pumila L., and Populus euphratica Oliv. The leaf decay rate was determined in 25 × 25 cm sized polyester litterbags with mesh sizes of 10,000 μm (coarse), 250 μm (medium), and 20 μm (fine). Decomposition in the coarse litterbags, allowing access by the entire decomposer community, was highest in P. euphratica at 61% weight loss after 367 days. In the same period, the weight loss in E. angustifolia was 51% and in U. pumila 52%. Combined correlation and multiple regression analyses revealed that decomposability was determined by mesh size, initial C/N ratio, crude fiber-to-N (CF/N) ratio, leaf area, and specific leaf area. A high correlation existed between traits impacting decomposition by the entire decomposer population and the digestibility of leaves by animals as measured in the laboratory (the in vitro digestibility). Initial leaf N (34 g N kg−1 DM) content was highest in E. angustifolia, followed by 23 g N kg−1 DM in U. pumila and 22 g N kg−1 DM in P. euphratica. The C/N ratio followed the order of P. euphratica (21.8) > U. pumila (19.4) > E. angustifolia (13.1). The CF/N ratio followed the order P. euphratica (5.2) > E. angustifolia (3.9) > U. pumila (2.9). Despite a lower decay rate and a higher N content remaining in leaves after 367 days in comparison to both other species, E. angustifolia had the highest potential for soil bio-amelioration. This was due to its foliage production (6 t ha−1 on average), which was about 2.5 times higher than that of the other species, giving a total leaf N loss of about 97 kg N ha−1 in coarse mesh bags. The N loss from U. pumila and P. euphratica leaves amounted to 33 and 23 kg N ha−1, respectively. The potential of leaf decomposition for supplementing soil N in the region depends on the decay rate, the initial leaf N content, the annual leaf biomass production, and differences between N contents over the course of the decomposition period. These can be additional criteria for selecting tree species suitable for afforestation of the degraded, irrigated croplands in Central Asia. [ABSTRACT FROM AUTHOR]

In Khorezm, a region located in the Aral Sea basin of Uzbekistan, water use for irrigation of predominantly cotton is high whereas water use efficiency is low. To quantify the seasonal water and salt balance, water application, crop growth, soil water, and groundwater dynamics were studied on a sandy, sandy loam and loamy cotton field in the years 2003 and 2005. To simulate and quantify improved management strategies and update irrigation standards, the soil water model Hydrus-1D was applied. Results showed that shallow groundwater contributed a substantial share (up to 399 mm) to actual evapotranspiration of cotton (estimated at 488–727 mm), which alleviated water stress in response to suboptimal quantities of water applied for irrigation, but enhanced concurrently secondary soil salinization. Thus, pre-season salt leaching becomes a necessity. Nevertheless, as long as farmers face high uncertainty in irrigation water supply, maintaining shallow groundwater tables can be considered as a safety-net against unreliable water delivery. Simulations showed that in 2003 around 200 mm would have been sufficient during pre-season leaching, whereas up to 300 mm of water was applied in reality amounting to an overuse of almost 33%. Using some of this water during the irrigation season would have alleviated season crop-water stress such as in June 2003. Management strategy analyses revealed that crop water uptake would only marginally benefit from a permanent crop residue layer, often recommended as part of conservation agriculture. Such a mulch layer, however, would substantially reduce soil evaporation, capillary rise of groundwater, and consequently secondary soil salinization. The simulations furthermore demonstrated that not relying on the contribution of shallow groundwater to satisfy crop water demand is possible by implementing timely and soil-specific irrigation scheduling. Water use would then not be higher than the current Uzbek irrigation standards. It is argued that if furrow irrigation is to be continued, pure sandy soils, which constitute <5% of the agricultural soils in Khorezm, are best to be taken out of annual cotton production. [ABSTRACT FROM AUTHOR]

Years of ill-managed irrigation have triggered secondary soil salinization in the Khorezm region of Uzbekistan located in the Aral Sea basin. To assess the magnitude and dynamics of secondary soil salinization, to quantify improved management strategies and to derive updated irrigation standards, the soil water model Hydrus-1D was used. Water and soil salinity dynamics in three cotton fields with different soil textures were monitored and simulated for the years 2003 and 2005. Until now in Khorezm, overall soil salinity could only be controlled by pre-season salt leaching using high amounts of water. This water, however, may not be available anymore in the near future because of global climate change and shrinking fresh water resources. Simulations confirmed that the present leaching practice is barely effective. At two out of the three locations within a sandy loam field, leaching did not remove salts from the 2 m profile. Instead, salts were only shifted from the upper (0–0.8 m) to the lower (0.8–2 m) soil layer. Strong groundwater contribution to evapotranspiration triggered secondary (re)-salinization of the topsoil during the cropping season. As a consequence, salt amounts in the top 0.8 m of soil increased from 9 to 22 Mg ha−1 in the field with loamy texture, and from 4 to 12 Mg ha−1 in the field with sandy texture. Management strategy analyses revealed that reducing soil evaporation by a surface residue layer would notably decrease secondary soil salinization. Here, owing to the reduced capillary rise of groundwater, post-season salt contents of the three fields were reduced by between 12 and 19% when compared with residue-free conditions. Even more effective would be improving the efficiency of the drainage system so as to lower the groundwater table. This would require a revision of the current irrigation management schemes, but could, as simulations revealed, reduce the post-season salt content in the 2 m soil profile of the three fields by between 36 and 59% when compared with unaltered conditions. For the revised irrigation management in total not more water than already foreseen by national irrigation recommendations would be needed. Increasing leaching and irrigation efficiency would help sustaining the present cotton production levels while reducing future leaching demands. [ABSTRACT FROM AUTHOR]

Groundwater (GW) management is an essential element in irrigated agriculture. This paper analyzes the temporal dynamics of GW table and salinity in Khorezm, a region of Uzbekistan which is situated on the lower Amu Darya River in the Aral Sea Basin and suffering from severe soil salinization. We furthermore identify the critical areas for potential soil salinization by examining GW table and salinity measured during 1990–2000 in 1,972 wells, covering the entire region. Additionally, case studies were performed to assess the contribution of the GW to the soil salinization on a field scale. Over the entire area, GW was only moderately saline averaging 1.75 ± 0.99 g l−1 However, GW levels were generally very shallow averaging 148 ± 57 cm below the ground surface and thus likely to prompt secondary soil salinization. Three case studies where GW table, soil and GW salinity were closely monitored at the field scale, suggested that the elevated GW levels forced soil salinization by annually adding 3.5–14 t ha−1 of salts depending on the position and salinity of the GW table. Maps interpolated from the regional dataset revealed that GW was significantly shallower and more saline in the western and southern parts of Khorezm despite the presence of a drainage network which is rather uniformly distributed throughout the region. The results of the current study will assist the development of an improved drainage management in Khorezm. [ABSTRACT FROM AUTHOR]

Impaired function of the phospholamban (PLB)-regulated sarcoplasmic reticulum Ca2+ pump (SERCA2a) contributes to cardiac dysfunction in heart failure (HF). PLB downregulation may increase SERCA2a activity and improve cardiac function. Small interfering (si)RNAs mediate efficient gene silencing by RNA interference (RNAi). However, their use for in vivo gene therapy is limited by siRNA instability in plasma and tissues, and by low siRNA transfer rates into target cells. To address these problems, we developed an adenoviral vector (AdV) transcribing short hairpin (sh)RNAs against rat PLB and evaluated its potential to silence the PLB gene and to modulate SERCA2a-mediated Ca2+ sequestration in primary neonatal rat cardiomyocytes (PNCMs). Over a period of 13 days, vector transduction resulted in stable >99.9% ablation of PLB-mRNA at a multiplicity of infection of 100. PLB protein gradually decreased until day 7 (7±2% left), whereas SERCA, Na+/Ca2+ exchanger (NCX1), calsequestrin and troponin I protein remained unchanged. PLB silencing was associated with a marked increase in ATP-dependent oxalate-supported Ca2+ uptake at 0.34 μM of free Ca2+, and rapid loss of responsiveness to protein kinase A-dependent stimulation of Ca2+ uptake was maintained until day 7. In summary, these results indicate that AdV-derived PLB-shRNA mediates highly efficient, specific and stable PLB gene silencing and modulation of active Ca2+ sequestration in PNCMs. The availability of the new vector now enables employment of RNAi for the treatment of HF in vivo.Gene Therapy (2007) 14, 211–218. doi:10.1038/sj.gt.3302872; published online 5 October 2006 [ABSTRACT FROM AUTHOR]

Rationale: Antiepileptic drugs are known to produce side effects which may impair driving performance. Performance effects, however, may differ substantially between individual antiepileptic drugs. Objective: To compare the effects of carbamazepine, remacemide, and placebo on actual driving performance during a 12-day incremental dosing regimen. Methods: Twenty-two healthy volunteers participated in a three-way, double-blind, cross-over driving study. Treatment effects were assessed in two actual driving tests carried out on days 8, 10, and 12 of each treatment period. The Road Tracking Test involved driving an instrumented vehicle at a constant speed and steady lateral position between the delineated lane boundaries. Standard deviation of lateral position (SDLP) was measured to indicate precision of road tracking control. The Car-Following Test involved driving the same vehicle behind a leading car and maintaining that distance while the latter executed a series of deceleration/acceleration maneuvers. Time to speed adaptation (TSA) and brake reaction time were the primary measures. Results: Remacemide did not affect the subjects' driving performance. Carbamazepine increased SDLP throughout treatment and lengthened TSA on day 8. Changes in SDLP relative to placebo were comparable to those previously seen in drivers conducting the same test with blood alcohol concentrations of 0.05 g/dl. Conclusion: Remacemide, at the given dose regimen, does not affect driving performance. Carbamazepine, at the given dose regimen, can produce mild but sufficient impairment to put epileptic patients at risk when driving, at least during initiation therapy. [ABSTRACT FROM AUTHOR]

Recombinant adenoviral vectors are broadly applied in gene therapy protocols. However, adenovector-mediated gene transfer has limitations in vivo. One of these is the low gene transfer rate into organs other than the liver after systemic intravenous vector injection. Local direct injection into the target organ has been used as one possible solution, but increases necessary equipment and methodology and is traumatic to the target. Wild-type adenovirus infection as well as adenovector-mediated gene transfer depends on virus interaction with the Coxsackie adenovirus receptor (CAR) mediating virus attachment to the cell surface, and on interaction with αvβ3 and αvβ5 integrins mediating virus entry into the cell. In order to assess the receptor-associated potential of different tissues to act as adenovector targets, we have therefore determined CAR and αv-integrin expression in multiple organs from different species. In addition, we have newly determined several human, rat, pig and dog CAR-mRNA sequences. Sequence comparison and structural analyses of known and of newly determined sequences suggests a potential adenovirus binding site between amino acids 29 and 128 of the CAR. With respect to the virus receptor expression patterns we found that CAR-mRNA expression was extremely variable between different tissues, with the highest levels in the liver, whereas αv-integrin expression was far more homogenous among different organs. Both CAR and αv-integrin showed similar expression patterns among different species. There was no correlation, however, between the adenovector expression patterns after intravenous, intracardiac and aortic root injection, respectively, and the virus receptor patterns. In summary, many organs carry both receptors required to make them potential adenovector targets. In sharp contrast, their actual targeting clearly indicates that... [ABSTRACT FROM AUTHOR]

Recently, we showed that L-propionylcarnitine did not affect recovery of regional contractile function of porcine myocardium subjected to 1 h of low-flow ischemia followed by 2 hr of reperfusion. In that study, ischemia may have been too severe and/or the duration of reperfusion too short to detect a beneficial effect of the compound. Therefore, in the present study we investigated the effects of saline (control group; n = 14) or pretreatment with L-propionylcarnitine (3 days of 50 mg/kg p.o. b.i.d. + 50 mg/kg i.v. prior to the experiment; n = 13) on recovery of regional contractile function of the myocardium in open-chest anesthetized pigs, subjected to two cycles of 10 min of left anterior descending coronary artery (LADCA) occlusion, each followed by 30 min of reperfusion. In the control animals, at the end of the second reperfusion period, systemic vascular resistance had increased by 18%, which, however, was not observed in the L-propionylcarnitine-treated pigs. In the control group, during the first occlusion, systolic segment length shortening (SSLS) of the LADCA-perfused area decreased from 18.5 ± 5.5% to - 3.7 = 3.2%. After 30 min of reperfusion, SSLS of the LADCA-perfused area had only partially recovered to 6.2 ±5.9%. During the second occlusion-reperfusion cycle similar values for SSLS were observed. In the treated animals., SSLS of the LADCA-perfused area was slightly improved after the second occlusion-reperfusion cycle (p = 0.056). This effect did not result in an overall improvement in cardiac pump function. We conclude that in a model of myocardial stunning, L-propionylcarnitine prevents systemic vasoconstriction in response to ischemia and reperfusion and, possibly as a result of this effect, slightly ameliorates post-ischemic hypofunction. (Mol Cell Biochem 116: 147-153, 1992) [ABSTRACT FROM AUTHOR]

Fish-oil nutrition leads to a change in fatty acid composition of cellular membranes. To investigate whether this affects cardiac responses to acute myocardial ischemia, pigs were fed a 9.1% (w/w) mackerel-oil (n=8) or 9.1% (w/w) lard-fat diet (n=8). Eight weeks mackerel-oil feeding reduced plasmacholesterol (51%) and triglyceride (48%), while the n-6 fatty acids of cardiac and platelet membrane phospholipids were partially replaced by n-3 fatty acids. After 8 weeks the animals were anesthetized and the left anterior descending coronary artery was occluded 6 times for a period of 5 min at 15 min intervals. Recovery of cardiac function and the incidence of cardiac arrhythmias were similar for both dietary groups. However, during the last reperfusions, hyperemic responses were less in magnitude and shorter lasting in the lard-fat (81±17 ml/min) than in the mackerel-oil group (129±18 ml/min). This may be caused by a difference in thromboxane synthesis, as coronary venous blood thromboxane B levels were higher in the lard-fat (77±6 pg/ml) than in the mackerel-oil group (19±7 pg/ml, P<0.05) during peak hyperemia. The low baseline levels of both thromboxane B and 6-keto prostaglandin F in fish-oil fed animals originate from the reduced content of precursor fatty acid in the membrane phospholipids. In conclusion, despite marked changes in membrane fatty acid composition induced by prolonged feeding with fish oil, no modification of recovery of cardiac function and of incidence of cardiac arrhythmias was found during acute recurrent ischemia. [ABSTRACT FROM AUTHOR]

The effects of biological, chemical and integrated control on the formation of selerotia of Rhizoctonia solani on new potato tubers were studied in experimental fields. Sprouts of seed tubers, sprouted in daylight, were inoculated with Verticillium biguttatum, an ecologically obligate mycoparasite of R. solani. Fungicides were mixed with the top soil. Biological control by V. biguttatum increased the percentage of harvests with less than 5% loss due to grading from 24% (non-inoculated) to 56%. Fungicides at the recommended rates usually gave good results but lower doses were less effective in sand than in loam soils. When fungicides were combined with biological control, the results were often, better: harvests with less than 5% sorting loss increased from 56 to 81%. Integrated control with pencycuron at 25% of the recommended rate was about equal to chemical control with pencycuron at full rate. The advantages of integrated control are discussed. [ABSTRACT FROM AUTHOR]

The effect of chronic norepinephrine (NE) administration with increasing dosage from 1-4 mg/kg over a period of 2 weeks was studied on cardiac phospholipids and their fatty acid distribution in rats. Animals were fed a control diet or a 10% cod liver oil (CLO)-enriched diet. The relative distribution of various polyunsaturated fatty acids esterified to the 1- and 2-position of the phosphatidylethanolamine fraction was estimated. NE stress during control feeding significantly reduced the total phospholipid content in rat heart. No differences in the phospholipid class distribution were found. However, CLO feeding as well as chronic NE administration resulted in a decrease of ω 3 fatty fatty acids, mainly C 18:2 ω 6 and C 20:4 ω 6, which was compensated with an increase in ω 3 fatty acids, mainly C 20:5 ω 3 and C 22:6 ω 3. The changes in fatty acid composition qualitatively agree with those reported by Gudbjarnason et al. (23), except that the mortality in our NE-treated control or CLO-fed groups was considerably lower. It can probably be attributed to a different mode of NE administration. On the other hand, at the end of the CLO feeding period in rats treated with NE or not, comparing with control fed rats without NE treatment, the incidence rate of ST segment elevation in electrocardiogram (ECG) recorded under light diethylether-induced anesthesia was higher. Independent of whether the fatty acid composition of myocardial phospholipids was dietary or pharmacologically manipulated, most of the polyunsaturated fatty acids were found at the 2-position of the phosphatidylethanolamine molecules. The polyunsaturated fatty acids account for 45-50% of the fatty acyl residues and preferentially occupy the 2-position, where they can exchange for each other. [ABSTRACT FROM AUTHOR]

It is well known that surface mulched crop residues (CR) lead to large yield increases of pearl millet (Pennisetum glaucum L.) on acid sandy soils of the West African Sahel. This effect is generally attributed to mulch-induced changes in chemical properties of the surface soil and the protection of millet seedlings from erosive sand storms. However, previous research has failed to separate the anti-erosive effects of CR on plant growth from chemical effects due to the release of nutrients during CR decomposition. To this end a mulching trial with surface applied millet stalks at a rate of 2000 kg ha?1,an equivalent 10% surface coverage obtained by inert polyethylene (PE) tubes and a bare control treatment was conducted from 1992 to 1994on an acid sandy soil in southwest Niger. Across treatments, sand flux at 0.1 m height was more than twice as high in the rainy seasons than in the dry months and mulching reduced sand flux by between 25 and 50% during rainy season storms compared with 67% during the dry season. Over the 21 months measurement period, cumulative erosion by wind and water was almost 270 t ha-1 of soil in unmulched control plots. In mulched plots, in contrast, between 160 and 200 t ha-1 of soil was deposited. Surface soil temperature at 0.01 mdepth reached above 40 deg. C in bare plots but was up to 4 deg. C lower with CR. Mulch reduced soil penetration resistance at 0-0.02 m and 0-0.05 depth by more than half and decreased runoff leading to higher water contents at flowering and grain filling in the upper 0.3 msoil layers in 1993 and throughout the entire profile in 1994, a year with particularly high rainfall. Both mulch types were similarly effective in increasing final stand density of millet in the first two years between 5 and 23% compared with bare control plots. Relative tothe bare control CR mulch effects on total dry matter of millet at harvest increased from 35% in 1992 and 108% in 1993 to 283% in 1994, wherea [ABSTRACT FROM AUTHOR]