The challenge of Lake Chilwa

Lake Chilwa and its environs present a unique challenge to science for two reasons: 1. The welfare of its people and the fish and crops on which they depend on incomes as well as subsistence are dominated by the vagaries of the periodic rise and fall of the lake. Inyears of high level the lake provides a relatively good living for the people of the plain and the fish is a major source of dietary protein for the densely populated Shire Highlands. Fish catches and fish consumption decline in years of low lake level. Could knowledge of the biology of the lake and the hydrology of the lake basin assist in stabilizing the fishing industry? 2. The area is underdeveloped, with the traditional matrilineal way of life, but it has considerable potential for a fishing industry, for agriculture, for livestock, for bird preservation and tourism and possibly, at some future date, for minerals. How can these interests be reconciled and in what order should developments take place

Breast feeding practices and views among diabetic women: a retrospective cohort study

Objective: to explore the pattern and experiences of breast-feeding practices among diabetic women. Design: retrospective cohort study using maternal records and postal questionnaires in a Baby-Friendly hospital. Participants: diabetic mothers including women with gestational diabetes, and type 1 and 2 diabetes mellitus. Findings: from the total group of respondents, 81.9% intended to breast feed. The actual breast feeding rates were 81.9% at birth, 68.1% at 2 weeks and 28.7% at 6 months postpartum. Major themes that were identified from women's experiences included information and advice, support vs. pressure, classification and labelling, and expectations. Conclusions: more than two-thirds of the diabetic women intended to breast feed and actually did breast feed in this study. For both the total study population and the type 1 and 2 diabetics alone, more than half were still breast feeding at 2 weeks postpartum, and approximately one-third were still breast feeding at 6 months postpartum. Implications for practice: structured support, provided for women through Baby-Friendly initiatives, was appreciated by the diabetic women in this study. The extent to which this support influenced the highly successful breast feeding practices in this group of women needs focused investigation. The need for a delicate balancing act between pressure and advice in order to prevent coercion was noted.</p

Effect of three surface conditioning methods to improve bond strength of particulate filler resin composites

The use of resin-based composite materials in operative dentistry is increasing, including applications in stress-bearing areas. However, composite restorations, in common with all restorations, suffer from deterioration and degradation in clinical service. Durable repair alternatives by layering a new composite onto such failed composite restorations, will eliminate unnecessary loss of tooth tissue and repeated insults to the pulp. The objective of this study was to evaluate the effect of three surface conditioning methods on the repair bond strength of a particulate filler resin-composite (PFC) to 5 PFC substrates. The specimens were randomly assigned to one of the following surface conditioning methods: (1) Hydrofluoric (HF) acid gel (9.5%) etching, (2) Air-borne particle abrasion (50 mum Al2O3), (3) Silica coating (30 mum SiOx, CoJet(R)-Sand). After each conditioning method, a silane coupling agent was applied. Adhesive resin was then applied in a thin layer and light polymerized. The low-viscosity diacrylate resin composite was bonded to the conditioned substrates in polyethylene molds. All specimens were tested in dry and thermocycled (6.000, 5-55 degreesC, 30 s) conditions. One-way ANOVA showed significant influence of the surface conditioning methods (p &lt;0.001), and the PFC types (p &lt;0.0001) on the shear bond strength values. Significant differences were observed in bond strength values between the acid etched specimens (5.7-14.3 MPa) and those treated with either air-borne particle abrasion (13.0-22.5 MPa) or silica coating (25.5-41.8 MPa) in dry conditions (ANOVA, p &lt;0.001). After thermocycling, the silica coating process resulted in the highest bond values in all material groups (17.2-30.3 MPa). (C) 2005 Springer Science + Business Media, Inc.</p

Renal phenotype of Et-1 transgenic mice is modulated by androgens

<p>Abstract</p> <p>Introduction</p> <p>Activation of the endothelin (ET) system promotes inflammation and fibrosis in various tissues including the kidney. Male ET-1 transgenic mice are characterized by chronic kidney inflammation and renal scarring. We hypothesized that this renal phenotype might be modulated by androgens. Thus the aim of our study was to elucidate the impact of gonadectomy in ET-1 transgenic mice on kidney function and morphology.</p> <p>Methods</p> <p>Male ET-1 transgenic mice at the age of 10 weeks were randomly allocated to the following groups: normal ET transgenic mice (ET; n = 17) and ET transgenic mice that underwent castration (ET+cas; n = 12). Study duration was 9 months. Creatinine clearance and protein excretion was monitored. At study end animals were sacrificed and kidneys were harvested for histology/immunhistochemistry.</p> <p>Results</p> <p>Castration significantly ameliorated glomerulosclerosis in ET-1 transgenic mice (ET glomerulosclerosis-score: 3.0 ± 0.17 vs ET+cas: 2.4 ± 0.17; p < 0.05) as well as renal perivascular fibrosis (ET fibrosis-score: 3.0 ± 0.14 vs ET+cas: 2.2 ± 0.14; p < 0.05). However, interstitial fibrosis and media/lumenratio of renal arteries remained unaffected by castration. Regarding inflammation, castration significantly reduced the number of CD4-positive cells in renal tissue of ET-1 transgenic mice (ET CD4-positive cells/10000 cells: 355 ± 72 vs ET+cas: 147 ± 28; p < 0.05). Renal tissue contents of CD8 positive cells as well as of macrophages were not affected by castration. Regarding kidney function castration significantly reduced proteinuria in ET-1 transgenic mice whereas creatinine clearance did not differ between study groups.</p> <p>Conclusion</p> <p>Our study demonstrates that the renal histopathological phenotype in male ET-1 transgenic mice with regard to glomerulosclerosis, proteinuria, perivascular fibrosis and immune cell immigration is ameliorated by castration. We thus conclude that the effects of ET-1 overexpression on renal tissue injury are modulated by androgens.</p

Intra-Examiner Reliability of Disposable Gnathometers

In vivo test methods using the expensive methods gnathodynamometry for assessing maximum bite-force, revealed objective improvement of retention of maxillary dentures using denture adhesives. Since the introduction of the disposable gnathometer (Procter & Gamble), facilitating simple measurement of bite-force at dislodgement of the denture, it seems relatively easy to measure the maximum bite-force of maxillary dentures. The gnathometer has a scale ranking from 1 to 10. It measures the pressure which a patient can apply to the front teeth until dorsally dislodgement of the maxillary denture. The aim of the present study was to test the intra-examiner reliability of gnathometers. In each of 5university dental clinics (Rotterdam, Groningen, Athens, Gent, and Istanbul) 5 patients who had received a new conventional complete maxillary denture less than one month previously, were selected. These patients had a stable natural dentition or prosthetic appliance in the mandible, e.g. an overdenture attached on natural or implant abutments, a partial natural dentition with a stable partial chromcobalt denture, etc. In the first session the maximum bite-force was measured by one experienced prosthodontist for each patient using three different gnathometers, successively three times with each gnathometer. If the result was between 2 ranking points, the lowest was registered. The 9 measurements were conducted with three-minute breaks in order to enable the patient to reposition the dentures comfortably and habitually. One week later at the same time of the day, these measurements were repeated with the same three gnathometers, respectively for each patient, as used in the first session. Intra-examiner reliability was very good. Paired sample correlations were 0.91, with overall measurement error of 0.7 on the ranking scale

Intra-Examiner Reliability of Disposable Gnathometers

In vivo test methods using the expensive methods gnathodynamometry for assessing maximum bite-force, revealed objective improvement of retention of maxillary dentures using denture adhesives. Since the introduction of the disposable gnathometer (Procter & Gamble), facilitating simple measurement of bite-force at dislodgement of the denture, it seems relatively easy to measure the maximum bite-force of maxillary dentures. The gnathometer has a scale ranking from 1 to 10. It measures the pressure which a patient can apply to the front teeth until dorsally dislodgement of the maxillary denture. The aim of the present study was to test the intra-examiner reliability of gnathometers. In each of 5university dental clinics (Rotterdam, Groningen, Athens, Gent, and Istanbul) 5 patients who had received a new conventional complete maxillary denture less than one month previously, were selected. These patients had a stable natural dentition or prosthetic appliance in the mandible, e.g. an overdenture attached on natural or implant abutments, a partial natural dentition with a stable partial chromcobalt denture, etc. In the first session the maximum bite-force was measured by one experienced prosthodontist for each patient using three different gnathometers, successively three times with each gnathometer. If the result was between 2 ranking points, the lowest was registered. The 9 measurements were conducted with three-minute breaks in order to enable the patient to reposition the dentures comfortably and habitually. One week later at the same time of the day, these measurements were repeated with the same three gnathometers, respectively for each patient, as used in the first session. Intra-examiner reliability was very good. Paired sample correlations were 0.91, with overall measurement error of 0.7 on the ranking scale