Showing papers by "University of Bedfordshire published in 2004"
TL;DR: It was concluded that static stretching as part of a warm-up may decrease short sprint performance, whereas active dynamic stretching seems to increase 20-m sprint performance.
Abstract: The purpose of this study was to determine the effect of different static and dynamic stretch protocols on 20-m sprint performance. The 97 male rugby union players were assigned randomly to 4 groups: passive static stretch (PSS; n = 28), active dynamic stretch (ADS; n = 22), active static stretch (ASST; n = 24), and static dynamic stretch (SDS; n = 23). All groups performed a standard 10-minute jog warm-up, followed by two 20-m sprints. The 20-m sprints were then repeated after subjects had performed different stretch protocols. The PSS and ASST groups had a significant increase in sprint time (p or = 0.05). The decrease in performance for the 2 static stretch groups was attributed to an increase in the musculotendinous unit (MTU) compliance, leading to a decrease in the MTU ability to store elastic energy in its eccentric phase. The reason why the ADS group improved performance is less clear, but could be linked to the rehearsal of specific movement patterns, which may help increase coordination of subsequent movement. It was concluded that static stretching as part of a warm-up may decrease short sprint performance, whereas active dynamic stretching seems to increase 20-m sprint performance.
338 citations
TL;DR: Characterisation of grey water reveals a source water that is similar in organic strength to a low-medium strength municipal sewage influent but with physical and biodegradability characteristics similar to a tertiary treated effluent.
267 citations
Book•
07 Apr 2004TL;DR: This paper presents a Cognitive Model of Psychosis, an Introduction to Cognitive Theory and Therapy, and Behavioural Techniques, which outline the techniques used in Therapy to treat Psychosis.
Abstract: Introduction. Preface. An Overview of Psychosis. An Introduction to Cognitive Theory and Therapy. Cognitive Model of Psychosis. Cognitive Assessment of Psychotic Patients. Formulation of the Case. Structure of Therapy. Difficulties in Engagement and the Therapeutic Relationship. Cognitive Techniques. Behavioural Techniques. Schema Change Processes. Negative Symptoms. Problems Associated with Psychosis. Relapse Prevention and Management. Integration of Homework into Therapy. Problems Related to Service Delivery and Context. Appendices.
187 citations
TL;DR: It was concluded that specific combined weights and plyometrics training can help increase CS and DD in club golfers.
Abstract: The purpose of this study was to determine the effect of a combined weights and plyometrics program on golf drive performance. Eleven male golfers' full golf swing was analyzed for club head speed (CS) and driving distance (DD) before and after an 8-week training program. The control group (n = 5) continued their normal training, while the experimental group (n = 6) performed 2 sessions per week of weight training and plyometrics. Controls showed no significant (p > or = 0.05) changes, while experimental subjects showed a significant increase (p < or = 0.05) in CS and DD. The changes in golf drive performance were attributed to an increase in muscular force and an improvement in the sequential acceleration of body parts contributing to a greater final velocity being applied to the ball. It was concluded that specific combined weights and plyometrics training can help increase CS and DD in club golfers.
158 citations
TL;DR: This work provides a dataset of chemicals that have been tested in the LLNA and the activity of which correspond with what is known of their potential to cause skin sensitization in humans, and hopes it will accelerate the development, evaluation and eventual validation of new approaches to skin‐sensitization testing.
Abstract: Allergic contact dermatitis resulting from skin sensitization is a common occupational and environmental health problem. In recent years, the local lymph node assay (LLNA) has emerged as a practical option for assessing the skin-sensitization potential of chemicals. In addition to accurate identification of skin sensitizers, the LLNA can also provide a reliable measure of relative sensitization potency, information that is pivotal in successful management of human health risks. However, even with the significant animal welfare benefits provided by the LLNA, there is interest still in the development of non-animal test methods for skin sensitization. Here, we provide a dataset of chemicals that have been tested in the LLNA and the activity of which correspond with what is known of their potential to cause skin sensitization in humans. It is anticipated that this will be of value to other investigators in the evaluation and calibration of novel approaches to skin-sensitization testing. The materials that comprise this dataset encompass both the chemical and biological diversity of known chemical allergens and provide also examples of negative controls. It is hoped that this dataset will accelerate the development, evaluation and eventual validation of new approaches to skin-sensitization testing.
129 citations
TL;DR: In this article, the authors developed several alternate future scenarios for conventional oil supply, given the current range of the estimates of resource availability and of future demand, and assuming that production will continue to increase unconstrained by political or economic factors such as deliberate withholdings or prolonged global recession.
127 citations
TL;DR: It is demonstrated that the nonlinear concentration‐dependent inhibition of Pseudomonas aeruginosa to EDTA can be used to successfully model and predict the potentiation of antimicrobials by EDTA.
Abstract: Aims: To demonstrate that the nonlinear concentration-dependent inhibition of Pseudomonas aeruginosa to EDTA can be used to successfully model and predict the potentiation of antimicrobials by EDTA.
Methods and Results: A model used successfully to describe the concentration-dependent inhibition of bacterial growth caused by many antimicrobials was unable to describe the inhibition of P. aeruginosa by EDTA. Examination of the inhibition profiles for EDTA against P. aeruginosa revealed a biphasic inhibitory pattern suggesting different mechanisms of action at different concentrations. A modelled, two-stage inhibitory process was shown to fit the observations. This model was then used to examine the effect of combining EDTA with other antimicrobials. The apparent synergy of mixtures of EDTA with quaternary ammonium surfactants (QAC) and specific antibiotics was successfully modelled. Minimum inhibitory concentrations (MIC) of the QAC and that of oxacillin and cefamandole were reduced by a factor of 3–10, whereas ampicillin was reduced by a factor of 70 from an MIC of 1524 to 21 mg l−1 in the presence of 500 mg l−1 of EDTA.
Conclusions: A nonlinear concentration-dependent inhibition of P. aeruginosa by EDTA gives rise to apparent observation of synergy with other antimicrobials.
Significance and Impact of the Study: This is a further example where the current methodology for the examination of antimicrobial synergy (the summed fractional inhibitory concentrations) leads to false conclusions.
110 citations
TL;DR: In this article, the authors investigated the individual experiences of those directly affected by the disorder and how parents make sense of the variety of different aetiological models, and found that the key issue for parents was the...
Abstract: Much of the extensive body VLf research into attention deficit hyperactivity disorder (ADHD) has concentrated on understanding the aetiology of the disorder. This research has generated a number of very different conceptualizations of ADHD, ranging from purely medical descriptions to theories that incorporate a range of social and psychological factors. Although a large amount of research has been undertaken in this area, little is known about the individual experiences of those directly affected by the disorder and, in particular, how parents make sense of the variety of different aetiological models. The aim of this study was to investigate this issue. The mothers of nine boys, aged between 8 and 11 years, agreed to participate in the study. One father also participated. In-depth interviews, following a semi-structured format, were held with each participant. Interviews were transcribed verbatim and analysed using a grounded theory approach. Data analysis revealed that the key issue for parents was the ...
99 citations
TL;DR: In this article, the failure properties and moduli of both avian feather and claw keratin in tension and the modulus of claw in compression were investigated. And they showed that increased water content acts to decrease stiffness and strength but to increase strain at failure.
Abstract: Despite recent research exploring the elastic properties of avian keratins, data on failure properties are less common in the literature. In this paper we present data on the failure properties and moduli of both avian feather and claw keratin in tension and the modulus of claw keratin in compression. Increased water content acts to decrease stiffness and strength but to increase strain at failure. The modulus of claw did not differ significantly when tested under tension and compression.
93 citations
TL;DR: The authors explored three categories of markers: attitude, certainty, and common knowledge markers, and its main aim is to compile a taxonomy of the lexical and discourse-based realisations of these markers and their pragmatic functions, as they are manifested in RAs from the field of electronic and electrical engineering.
91 citations
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TL;DR: In this paper, the morphological opening operator is defined, which consists in dilating the image previously eroded using the same structuring element, and the dual operator of morphological closing is defined.
Abstract: The erosion of an image not only removes all structures that cannot contain the structuring element but it also shrinks all the other ones. The search for an operator recovering most structures lost by the erosion leads to the definition of the morphological opening operator. The principle consists in dilating the image previously eroded using the same structuring element. In general, not all structures are recovered. For example, objects completely destroyed by the erosion are not recovered at all. This behaviour is at the very basis of the filtering properties of the opening operator: image structures are selectively filtered out, the selection depending on the shape and size of the SE. The dual operator of the morphological opening is the morphological closing. Both operators are at the basis of the morphological approach to image filtering developed in Chap. 8.
TL;DR: The negative and positive effects of the nine newer antiepileptic drugs that have received a product licence in the UK or in the US are reviewed and careful individual assessment of each patient should enable the clinician to determine whether the medication or some other factor is responsible for any behavioural disturbance.
Abstract: The negative and positive effects of the nine newer antiepileptic drugs that have received a product licence in the UK or in the US are reviewed. The importance of avoiding misinterpretation of the data because of confounding factors such as alternative psychosis, the release phenomenon or drug interactions is emphasised. Vigabatrin has been associated with both psychosis and depression. Due to the concentric visual field defects that may occur with vigabatrin, its use is now limited, although it remains the drug of choice for infantile spasms. Lamotrigine seems to be largely associated with improvement rather than deterioration of mood and behaviour. It may have a role in treating affective disorder. Gabapentin probably has relatively little effect on behaviour but may exacerbate behavioural problems in some children with pre-existing difficulties. Topiramate may precipitate both psychosis and depression, but these are less likely to occur if the currently recommended lower starting doses, escalation rates and target doses are used. The data for tiagabine are limited, but there is no clear evidence for psychosis or depression being caused by this drug. Oxcarbazepine may be of value in treating mood disorder, but the information is very limited. There are few reports of behavioural disturbances with levetiracetam, but the data suggest that there is no significant increase in psychosis or depression. There are some reports of psychosis and other behavioural disturbances with felbamate, but the use of this drug is limited by the serious adverse effects of hepatotoxicity and aplastic anaemia. There is some evidence for psychosis with zonisamide, but there is also a suggestion that this drug may be of benefit in treating psychiatric disorders. Careful individual assessment of each patient should enable the clinician to determine whether the medication or some other factor is responsible for any behavioural disturbance.
TL;DR: An analytical model was developed that considers the interplay between the mass transfer of flavour across the interface of the particles and that across the air-liquid interface to show that in-mouth release of aroma from the dispersion of gelled emulsion particles follows a two-component kinetic equation with fast and slow components.
TL;DR: A simple equilibrium partitioning model was constructed to explore the relative rates of removal by different mechanisms (reaction vs. deposition) for siloxanes and their resultant silanols and predictions were relatively insensitive to assumed departures from phase equilibrium.
TL;DR: The potential for gene expression profiling to identify toxic hazards by the identification of mechanistically relevant markers of toxicity is demonstrated, and some variability in the quantitative nature of the microarray data is indicated.
Abstract: Microarrays have the potential to significantly impact our ability to identify toxic hazards by the identification of mechanistically relevant markers of toxicity. To be useful for risk assessment, however, microarray data must be challenged to determine reliability and interlaboratory reproducibility. As part of a series of studies conducted by the International Life Sciences Institute Health and Environmental Science Institute Technical Committee on the Application of Genomics to Mechanism-Based Risk Assessment, the biological response in rats to the hepatotoxin clofibrate was investigated. Animals were treated with high (250 mg/kg/day) or low (25 mg/kg/day) doses for 1, 3, or 7 days in two laboratories. Clinical chemistry parameters were measured, livers removed for histopathological assessment, and gene expression analysis was conducted using cDNA arrays. Expression changes in genes involved in fatty acid metabolism (e.g., acyl-CoA oxidase), cell proliferation (e.g., topoisomerase II-Alpha), and fatty acid oxidation (e.g., cytochrome P450 4A1), consistent with the mechanism of clofibrate hepatotoxicity, were detected. Observed differences in gene expression levels correlated with the level of biological response induced in the two in vivo studies. Generally, there was a high level of concordance between the gene expression profiles generated from pooled and individual RNA samples. Quantitative real-time polymerase chain reaction was used to confirm modulations for a number of peroxisome proliferator marker genes. Though the results indicate some variability in the quantitative nature of the microarray data, this appears due largely to differences in experimental and data analysis procedures used within each laboratory. In summary, this study demonstrates the potential for gene expression profiling to identify toxic hazards by the identification of mechanistically relevant markers of toxicity.
TL;DR: There is insufficient safety information from the randomised controlled trials to confirm a definite association between SSRIs and suicidality, and analysis of suicide and antidepressant prescribing trends in three countries and a large case-control study do not support the hypothesis that there is a link between use of SSRIS and death caused by suicide.
Abstract: Depression is a serious condition, associated with considerable morbidity and mortality; selective serotonin reuptake inhibitors (SSRIs) were commonly used in its treatment in child and adolescent psychiatry until recently. In the wake of the recent UK Committee on Safety of Medicines (CSM) advice, we conducted a rapid review of current available information on SSRIs and suicidality (suicidal ideation, self-harm and suicide attempt) in children and adolescents from clinical trials and epidemiological studies. There is insufficient safety information from the randomised controlled trials to confirm a definite association between SSRIs and suicidality. Furthermore, analysis of suicide and antidepressant prescribing trends in three countries and a large case-control study do not support the hypothesis that there is a link between use of SSRIs and death caused by suicide. Regulatory agencies and the media should have strict guidelines for the management of information relating to the treatment of this condition so that clinicians can make properly informed decisions. We suggest clinical guidelines for managing depression in children and adolescents. SSRIs should not be considered for use as first-line treatment in mild or moderate depression of childhood, where psychological interventions such as cognitive behaviour therapy or interpersonal therapy are the mainstay. SSRIs should be considered when there is severe depression that does not respond to psychological interventions; when the child is suicidal and is admitted as an inpatient, is severely depressed or has bipolar depression despite adequate doses of mood-stabilisation agents; or when the child or family prefers pharmacotherapy to psychological interventions and gives informed consent. Local bodies of clinicians or peer groups should agree protocols and acceptable guidelines, taking into consideration the type of patients being assessed, the availability of nonpharmacological intervention, and the benefit-risk ratio of the pharmacological intervention. It is important that parents (and patients when possible) be given accurate information regarding the current controversy over SSRI prescribing. More research into the use of SSRIs in childhood depression is urgently required.
TL;DR: To analyse population minimum inhibitory concentrations data from clinical strains of Staphylococcus aureus and Pseudomonas aeruginosa for changes over a 10‐year period and to look for correlations between the antimicrobials tested.
Abstract: Aims: To analyse population minimum inhibitory concentrations (MICs) data from clinical strains of Staphylococcus aureus and Pseudomonas aeruginosa for changes over a 10-year period and to look for correlations between the antimicrobials tested.
Methods and Results: Data from the MIC study of 256 clinical isolates of Staph. aureus [169 methicillin-sensitive Staph. aureus (MSSA), 87 methicillin-resistant Staph. aureus (MRSA)] and 111 clinical isolates of Ps. aeruginosa against eight antimicrobial biocides and several clinically relevant antibiotics was analysed using anova, Spearman-Rho correlation and principal component analysis. Comparisons suggest that alterations in the mean susceptibility of Staph. aureus to antimicrobial biocides have occurred between 1989 and 2000, but that these changes were mirrored in MSSA and MRSA suggests that methicillin resistance has little to do with these changes. Between 1989 and 2000 a sub-population of MRSA has acquired a higher resistance to biocides, but this has not altered the antibiotic susceptibility of that group. In both Staph. aureus and Ps. aeruginosa several correlations (both positive and negative) between antibiotics and antimicrobial biocides were found.
Conclusions: From the analyses of these clinical isolates it is very difficult to support a hypothesis that increased biocide resistance is a cause of increased antibiotic resistance either in Staph. aureus or in Ps. aeruginosa.
Significance and Impact of the Study: The observation of negative correlations between antibiotics and biocides may be a useful reason for the continued use of biocides promoting hygiene in the hospital environment.
TL;DR: The relevance-theoretic view of covert communication in advertising has been explored in this article, where it is argued that cognitive consistency and innate human meta-representational abilities are far more central to a cognitive pragmatic account of advertisements than the notion of covert communications.
30 Jan 2004
TL;DR: It was found that stage III oocytes were more susceptible to chilling than stage V oocytes, and that individual female had a significant influence (p < 0.0001) on oocyte chilling sensitivity.
TL;DR: The combined effect of ionic calcium and ethanol on the visual creaming behavior and rheology of sodium caseinate-stabilized emulsions and the state of aggregation was correlated with emulsion microstructure from confocal laser scanning microscopy.
TL;DR: In this article, the interfacial properties of homogenised mixtures of monoglycerides and milk proteins (casein) have been examined using dynamic surface rheology.
TL;DR: The metal content of the aerosol samples, especially soluble metals such as Zn, is suggested to be the primary component responsible for oxidative damage of the DNA, and therefore most implicated in any health effects arising from the inhalation of these particulate cocktails.
TL;DR: This brief Comment outlines why it is plausible that new paradigms could be developed to enable risk assessment to support consumer safety decisions, without the need to generate data in animal tests.
Abstract: At present, we are unable to use much of the data derived from alternative (non-animal) tests for human health risk assessment. This brief Comment outlines why it is plausible that new paradigms could be developed to enable risk assessment to support consumer safety decisions, without the need to generate data in animal tests. The availability of technologies that did not exist 10 years ago makes this new approach possible. The approach is based on the concept that data and information derived from applying existing and new technologies to non-animal models can be interpreted in terms of harm and disease in man. A prerequisite is that similar data and information generated in a clinical setting are available to permit this "translation". The incorporation of this additional translation step should make it possible to use data and information generated in non-animal models as inputs to risk assessment. The new technologies include genomics, transcriptomics, proteomics and metabonomics. Their application to in vitro and human "models" enables large amounts of data to be generated very quickly. The processing, interpretation and translation of these data need to be supported by powerful informatics capabilities and statistical tools. The use of integrated "systems biology" approaches will further support the interpretation by providing better understanding of the underlying biological complexity and mechanisms of toxicity. Clinical medicine is using the opportunities offered by the new "omics" technologies to advance the understanding of disease. The application of these technologies in clinical medicine will generate massive amounts of data that will need processing and interpretation to allow clinicians to better diagnose disease and understand the patients' responses to therapeutic interventions. Support from clinical epidemiology will be essential. If these data and information can be made generally accessible in an ethical and legal way, they should also permit the "translation" of experimental non-animal data, so that they can then be used in risk assessment.
Journal Article•
TL;DR: Head positions adopted by aircrew in air combat have been quantified, and the associated levels of cervical muscle activation have been determined, to help devise targeted neck conditioning and positioning strategies in order to reduce injury risk.
Abstract: Introduction Specific mechanisms leading to acute neck injury in flight as a result of +Gz exposure remain unclear In this study, head positions adopted by aircrew in air combat have been quantified, and the associated levels of cervical muscle activation have been determined Method Six fast jet aircrew subjects were instrumented with surface electromyography (EMG) electrodes, and activation potentials from neck erector spinae (ES) and sternocleidomastoid (SC) muscles were logged on a data recorder EMG signal was normalized to preflight maximum voluntary contraction (MVC) All subjects flew a one-on-one air combat sortie in a Hawk T1 aircraft comprising at least four air combat engagements In-cockpit video and +Gz acceleration were recorded Time-synchronized analysis of video, EMG, and acceleration were conducted for head position and normalized muscle activation (%MVC) Results During air combat, the head was away from neutral for 68% of the time, predominantly in extension, or rotation plus extension During neck extension under G, 40-80% MVC occurred in the ES: this was reduced by half when the canopy was used as a support Similar activation occurred in the SC in neck extension plus rotation The ES was activated at over 40% MVC for 25% of the engagement duration Postsortie, 35% reduction in neck muscle strength occurred Conclusions Extreme neck extension +/- rotation is very common in air combat and is associated with high levels of muscle activation and fatigue This information can be used to help devise targeted neck conditioning and positioning strategies in order to reduce injury risk
Patent•
14 Apr 2004TL;DR: A vehicle seat assembly has a passenger seat with a seat member and a back rest part, and a child seat assembly with a seating part and a rear rest part as discussed by the authors, which provides first and second alternative child seat configurations.
Abstract: A vehicle seat assembly has a passenger seat with a passenger seat member and a passenger seat back, and a child seat assembly with a seating part and a back rest part. The child seat assembly provides first and second alternative child seat configurations. In one embodiment, the seat assembly has a passenger seat member which is movable between a first position in which the child seat assembly is substantially hidden from view and a second position in which the child seat assembly is exposed to enable the first child seat configuration to be unfolded to seat a child passenger. The child seat assembly may be mounted so that it can be removed completely from the assembly. In another embodiment, the passenger seat member is movable between a first position in which a seating surface is defined for an adult passenger, and a second position in which, for example, a reverse side of the seat member defines a back rest surface for a child passenger.
Journal Article•
TL;DR: The sensitivity of oocytes to cryoprotectants appeared to increase with development stage with stage V oocytes being the most sensitive.
Abstract: Cryopreservation of fish germ cells is an important measure in conservation of fish genetic material. Although investigations on cryopreservation of fish sperm and embryos have been carried out extensively, cryopreservation of fish oocytes has not been studied systematically. In the present study the toxicity of cryoprotectants to zebrafish (Danio rerio) oocytes was investigated. Commonly used cryoprotectants dimethyl sulfoxide (DMSO), methanol, ethylene glycol (EG), propylene glycol (PG), sucrose and glucose were studied. Stage III (vitellogenic), stage IV (maturation) and stage V (mature egg) zebrafish oocytes were incubated in Hank's medium containing different concentrations of cryoprotectants (0.25-4M) for 30 min at room temperature. Three different tests were used to assess oocyte viability: trypan blue (TB) staining, thiazolyl blue (MTT) staining and in vitro maturation followed by observation of germinal vesicle breakdown (GVBD). Results showed that the toxic effect of cryoprotectant on oocytes generally increased with increasing concentration. MTT test was shown to be the least sensitive testing method and gave poor correlation to subsequent GVBD results. Sensitivity of vital tests increases in the order of MTT, TB and GVBD. GVBD test showed that cryoprotectant toxicity to stage III zebrafish oocytes increased in the order of methanol, PG, DMSO, EG, glucose and sucrose. No Observed Effect Concentrations (NOECs) for stage III oocytes were 2M, 1M, 1M, 0.5M, less than 0.25M and less than 0.25M for methanol, PG, DMSO, EG, glucose and sucrose respectively. TB test also showed that the toxicity of tested cryoprotectants increased in the same order. The sensitivity of oocytes to cryoprotectants appeared to increase with development stage with stage V oocytes being the most sensitive.
TL;DR: Polymorphic transitions from the initial beta' phase to the beta phase accompanied the formation of bloom at all temperatures, and the bloom consisted principally of solid fat and was sharper melting than was the fat in the chocolate.
Abstract: Palm kernel stearin and hydrogenated palm kernel stearin can be used to prepare compound chocolate bars or coatings. The objective of this study was to characterize the chemical composition, polymorphism, and melting behavior of the bloom that develops on bars of compound chocolate prepared using these fats. Bars were stored for 1 year at 15, 20, or 25 degrees C. At 15 and 20 degrees C the bloom was enriched in cocoa butter triacylglycerols, with respect to the main fat phase, whereas at 25 degrees C the enrichment was with palm kernel triacylglycerols. The bloom consisted principally of solid fat and was sharper melting than was the fat in the chocolate. Polymorphic transitions from the initial beta' phase to the beta phase accompanied the formation of bloom at all temperatures.
TL;DR: The results of a 'BioWise' demonstration project to assess the comparative sensitivity and practicality of seven new assays for the direct assessment of ecotoxicity in industrial effluents are presented.
Abstract: The results of a ‘BioWise’ demonstration project to assess the comparative sensitivity and practicality of seven new assays for the direct assessment of ecotoxicity in industrial effluents are presented. In addition the aim of the project was to validate the results of the new assays against benchmark data generated from non-proprietary, rapid, microplate screening assays using the regulatory species; freshwater crustacean Daphnia magna and green algae Selenastrum capricornutum, chosen in view of their environmental relevance. The new commercial test assays were: Daphnia magna, Selenastrum capricornutum and Thamnocephalus platyurus Toxkits® supplied by Vickers Laboratories Ltd, containing dormant, immobilised life stages of the test species; GreenScreen® EM, a yeast based assay for genotoxicity and general acute toxicity supplied by Gentronix Ltd; and CellSense® a mediated, amperometric whole cell biosensor based on immobilised activated sludge and E. coli. 38 effluent samples supplied by members of SOCSA (Specialised Organic Chemicals Sector Association) were examined over a period of 13 months, in the project co-ordinated by the AstraZeneca Brixham Environmental Laboratory, and part funded by BioWise via the UK Government Department of Trade and Industry.
TL;DR: In this paper, the effects of pit size in the ngoro conservation system on soil water conservation and yield of maize were evaluated in two sites near Lipumba village on the Matengo highlands in Mbinga District, Ruvuma Region, in southern Tanzania.
Abstract: The Matengo people, in SW Tanzania, developed the ngoro conservation system several hundred years ago and it is a very effective indigenous manual cultivation practice for steep slopes. It deserves wider recognition and investigation to gain a quantitative understanding of the conservation system processes and its management to see whether it can be adapted to be more cost effective with limited land and labour resources. The objective of the study was to evaluate the effects of pit size in the ngoro cultivation system on soil water conservation and yield of maize ( Zea mays L.). A field experiment was conducted in 1995/1996 at two sites near Lipumba village on the Matengo highlands in Mbinga District, Ruvuma Region, in southern Tanzania. The ngoro comprise a matrix of pits with surrounding bund walls and this indigenous system is used extensively on the steep slopes (typically 20–50%) of Mbinga District. Grass is cut prior to cultivation and laid out in a matrix, traditionally about 1.5 m ×1.5 m square, soil is then dug from the middle of each square and placed to cover the cut grass to form four bunds surrounding each pit. Crops are planted on these bund walls (ridges), under which buried decomposing plant residues provide nutrients and also ingeniously allow seepage of excessive water across the ngoro system. The ngoro pit size treatments comprised N 1 ( 1 m ×1 m), N 1.5 ( 1.5 m ×1.5 m) and N 2 ( 2 m ×2 m) laid in a randomised complete block design with four replications. Although ngoro profiles were degraded over time, the net loss of soil from the system was negligible as the majority of soil was redeposited in the pit. N 2 was found to be the most suitable pit size on steep slopes. Pit size did not significantly influence the soil moisture regime as measured in this study. Increase in pit size generally resulted in decreased soil penetration resistance and improved plant growth resulting in the highest grain yield being obtained from the 2 m ×2 m ngoros. Increasing the pit size reduced labour input requirements and thereby markedly boosted the profitability of the system.