Internal charge behaviour of nanocomposites

The incorporation of 23 nm titanium dioxide nanoparticles into an epoxy matrix to form a nanocomposite structure is described. It is shown that the use of nanometric particles results in a substantial change in the behaviour of the composite, which can be traced to the mitigation of internal charge when a comparison is made with conventional TiO2 fillers. A variety of diagnostic techniques (including dielectric spectroscopy, electroluminescence, thermally stimulated current, photoluminescence) have been used to augment pulsed electro-acoustic space charge measurement to provide a basis for understanding the underlying physics of the phenomenon. It would appear that, when the size of the inclusions becomes small enough, they act co-operatively with the host structure and cease to exhibit interfacial properties leading to Maxwell-Wagner polarization. It is postulated that the particles are surrounded by high charge concentrations in the Gouy-Chapman-Stern layer. Since nanoparticles have very high specific areas, these regions allow limited charge percolation through nano-filled dielectrics. The practical consequences of this have also been explored in terms of the electric strength exhibited. It would appear that there was a window in which real advantages accrue from the nano-formulated material. An optimum loading of about 10% (by weight) is indicated

Oral candida infection among HIV patients at Kilimanjaro Christian Medical Centre in northern, Tanzania

Background: Oral candidiasis has been a global health challenge especially in immunocompromised patients particularly with HIV infection. Though the incidence and prevalence of opportunistic infections have been reduced due to the use of anti-retroviral therapy (ART), oral candidiasis remains the most frequently HIV-associated oral lesion in Tanzania. This study aimed at determining the prevalence of oral candida infection in HIV positive patients and investigate the relationship between oral manifestations and the level of immunosuppression. Method: This study was carried out at Kilimanjaro Christian Medical Centre in Moshi, Tanzania. The study included 314 HIV patients with complete clinical results records who were diagnosed with HIV and who were on ARV and attending the hospital for care and treatment. Results: Prevalence of oral candida was 42.0% (132/314). Age group 6-27 years accounted for half of the infections (49/98).  A significantly higher prevalence of candida infection  (66.7%; 24/36) was obseved among patients with <200 cells/µl than in those with 200-500 cells/µl or >500 cells/µl (Chi-square χ2=14.9, p=0.001). The mean CD4+T-cell counts in HIV patients infected with oral candida was lower (523±35) than patients without oral candida infection (645±31 cells/µl), (ANOVA, p= 0.009). The mean CD4+ T-cell count among HIV patients on ART and those not on ART was not statistically different. Conclusion: The prevalence of oral candida infection was significantly higher in patients with CD4+ cell counts less than 200 cells/µl

Prevalence and Factors Associated with Diabetes and Hypertension Among HIV Patients at Tertiary Hospital, Kilimanjaro, Tanzania

Introduction: Diabetes and hypertension are prevalent non-communicable diseases that significantly affect people living with HIV, particularly those on antiretroviral therapy. Despite the increasing recognition of these conditions, their prevalence and associated risk factors among people living with HIV in Tanzania remain underexplored. This study aimed to determine the prevalence and risk factors of diabetes and hypertension among HIV patients attending Child-Centred Family Care Clinic at KCMC Hospital. Methods: A cross-sectional study was conducted from May to June 2024, involving 341 people living with HIV attending the Child-Centred Family Care Clinic at KCMC Hospital. Data were collected through face-to-face interviews, file reviews, and physical measurements. Hypertension was defined as systolic blood pressure ≥ 140 mmHg/ or diastolic blood pressure ≥ 90 mmHg. Diabetes was defined as blood glucose level of ≥140 mg/dL. A logistic regression model was used to identify factors associated with diabetes and hypertension.  Results: Prevalence of hypertension was 23.5% (80) while the prevalence of 14.1% (48) was diabetes. Hypertension was most prevalent in individuals aged 36-62 years (71.3%), whereas 70.9% of diabetic patients reported a family history of diabetes. Multivariate analysis revealed that older age was significantly associated with hypertension, with participants aged 18-35 years showing a lower likelihood of hypertension (AOR=0.10; 95% CI: 0.03-0.41; p=0.004) compared to those over 63 years. Participants earning TZs 500,000 or more per month were more likely to develop diabetes as compared to others (AOR=4.112; 95% CI: 1.199-14.108; p=0.025).  Conclusion: The findings indicate that socioeconomic determinants are critical in influencing the prevalence of diabetes and hypertension among people living with HIV, suggesting that interventions should focus on improving screening and early treatment to at risk groups

Mapping neuro-disabilities and their dimensions among under 5 years of age children in the southern agricultural corridor of Tanzania: a preliminary baseline survey

BackgroundNeuro-disabilities involve impairments of the nervous system, affecting brain development and functioning. Due to limited scientific data on neuro-disabilities in Tanzania, this study examines maternal characteristics in high-risk areas, such as the Southern Agricultural Growth Corridor (SAGCOT).MethodsThis cross-sectional study sampled 286 children aged 0–5 years and their mothers in the SAGCOT region. Each mother selected the youngest child within the specified age range. Multi-stage sampling was used to choose clusters and areas for the study. The Malawi Developmental Assessment Tool (M-DAT) was used to assess the children’s developmental levels. Descriptive analysis determined distribution patterns, while multivariate analyses were performed to identify significant factors. Modified Poisson regression with robust standard errors estimated prevalence ratios (PRs) and their 95% confidence intervals (CIs).ResultsThe study included 286 mother–child pairs from four clusters: Ihemi, Kilombero, Ludewa, and Mbarali. The children’s median age was 24 months, with the majority aged between 13 and 48 months. Boys constituted a slight majority (59.4%). The majority of mothers were married (72.4%), had primary education (56.6%), and were engaged in non-farming occupations (56.3%). Neurodevelopmental assessments revealed that 11.2% of children were fully developed, while 88.8% exhibited development delays. Adjusted prevalence ratios (aPR) with 95% confidence intervals identified significant associations between developmental domains and demographic variables such as age, gender, marital status, and maternal occupation.ConclusionThe study highlights a high prevalence of neuro-disability among children in Tanzania’s southern corridor, revealing disparities across regions and the impact of factors such as gender and marital status. Targeted interventions are essential to address these developmental challenges effectively and promote optimal child development and wellbeing

"Ruvettiin jakamaan maapalloa keskenämme" : Helsingin Sanomien kehitysmaauutisointi vuosina 1965–1974

Tarkastelen tutkielmassani Helsingin Sanomien (HS) kehitysmaauutisointia vuosina 1965–1974. Tavoitteena on selvittää, miten yhteiskunnan ja journalismin merkittävä murroskohta heijastui Suomen suurimman sanomalehden välittämään maailmankuvaan. Päälähteinä ovat tekemäni aikalaistoimittajien haastattelut, Päivälehden arkiston teettämät toimittajahaastattelut ja muu arkistomateriaali sekä digitaalisessa muodossa löytyvät HS:n lehdet vuosilta 1965–1974. Tarkempi analyysi kohdistuu huhti- ja lokakuun lehtiin vuosina 1965, 1968, 1971 ja 1974. Tutkimukseni perusteella HS:n kehitysmaauutisoinnissa tapahtui selkeitä muutoksia. Vuonna 1965 pääpaino oli kansainvälisten uutistoimistojen sähkeuutisissa. Sähkeet kattoivat määrällisesti suuren joukon maita, mutta aiheiden käsittely jäi pintapuoliseksi ja näkökulmat olivat uutistoimistojen valitsemia. Omien toimittajien nimiin kirjattuja juttuja kehitysmaa-aiheista ei vuonna 1965 juuri ollut. Vuonna 1968 tilanne oli samankaltainen. Esimerkiksi maailmalla ja Suomessa suurta huomiota herättänyttä Biafran kriisiä ei analysoitu omien toimittajien voimin, eikä HS lähettänyt alueelle omaa toimittajaa. Vuoteen 1971 mennessä ulkomaantoimituksen omien toimittajien kirjoittamien, kehitysmaita käsittelevien juttujen määrä kasvoi selvästi. Myös pidempien artikkeleiden määrä lisääntyi, samoin tekstien kommentoiva ja kantaaottava tyyli. Vuonna HS:ssa oli jo kolme Euroopan ja Pohjois-Amerikan ulkopuolisia alueita seuraavaa toimittajaa. Vuosina 1971–1974 isoin muutos näyttäisi tapahtuneen aihepiirien laventumisessa: maailman eriarvoisuuteen ja humanitaarisiin ongelmiin liittyvät artikkelit lisääntyivät. Kehitysmaauutisoinnin rinnalle alkoi nousta kehitysmaajournalismi, joka pyrki tuomaan esiin kehityskysymyksiä ja kehitysmaiden näkökulmia. Myös kehitysmaita seuraavien toimittajien työmatkat kohdealueilleen lisääntyivät. Kaikki tutkimukseen haastatellut HS:n ulkomaantoimittajat olivat sitä mieltä, että uutispäällikkö Olli Kivisellä oli merkittävä rooli uudenlaisen uutisoinnin muovaajana. Taustalla vaikutti myös Aatos Erkon vuonna 1965 käynnistämä muutosprosessi HS:n uudistamiseksi. Erkko halusi huomioida ajan hengen ja avasi ovet nuorelle, usein vasemmistolaiselle, toimittajapolvelle. Tutkimukseni tarkastelujaksolla HS:n kehitysmaita seuraavat toimittajat olivat 1940-luvulla syntyneitä nuoria miehiä, joilla yliopisto-opinnot olivat juuri takana tai meneillään. Kaikki olivat aatemaailmaltaan selkeästi vasemmistolaisia, ja kirjoitusten pontimena oli halu valistaa lukijoita ja vaikuttaa siihen, että imperialistinen maailmanjärjestys jää historiaan. Vaikka HS säilyi arvoiltaan oikeistoliberaalina, se näyttää sallineen “radikaalitoimittajilleen” hyvinkin vasemmistolaisia kannanottoja varsinkin vuosina 1969–1974

Community-based rehabilitation and disability-inclusive development: On a winding path to an uncertain destination

The majority of people with disabilities who live in developing countries, predominantly in the global South, do not receive any formal disability or rehabilitation services. In those countries or regions where at least some disability services are provided, the community-based rehabilitation (CBR) approach, or some form of it, is likely to be the only approach available (Evans et al. 2001)

Density-dependent network structuring within and across wild animal systems

Theory predicts that high population density leads to more strongly connected spatial and social networks, but how local density drives individuals' positions within their networks is unclear. This gap reduces our ability to understand and predict density-dependent processes. Here we show that density drives greater network connectedness at the scale of individuals within wild animal populations. Across 36 datasets of spatial and social behaviour in >58,000 individual animals, spanning 30 species of fish, reptiles, birds, mammals and insects, 80% of systems exhibit strong positive relationships between local density and network centrality. However, >80% of relationships are nonlinear and 75% are shallower at higher values, indicating saturating trends that probably emerge as a result of demographic and behavioural processes that counteract density's effects. These are stronger and less saturating in spatial compared with social networks, as individuals become disproportionately spatially connected rather than socially connected at higher densities. Consequently, ecological processes that depend on spatial connections are probably more density dependent than those involving social interactions. These findings suggest fundamental scaling rules governing animal social dynamics, which could help to predict network structures in novel systems

The role of rodents and small carnivores in plague endemicity in Tanzania

Belgian Journal of Zoology 2005, 135 (supplement) : 119-125Between 1974 and 2003, blood samples were collected from wild and commensal rodents, and wild and domestic small carnivores in selected villages of seven districts in Tanzania that have experienced human plague outbreaks and seven districts that have not experienced any outbreak of the disease. The samples were tested for antibodies against Yersinia pestis Fraction I antigen, using passive haemagglutination (PHA) or ELISA tests. Of the 3354 rodents and 558 small carnivores from the plague infected districts, 122 (3.6%) rodents (captured in Mbulu and Lushoto districts) were plague positive; 29 (5.2%) small carnivores from Mbulu, Arumeru, Hai and Lushoto districts were plague positive, 28 of these were domestic dogs (Canis familiaris). PCR tests showed that 17.5% of 211 rodents tested from Lushoto contained Y. pestis DNA. In the non-infected districts, 1545 rodents and 171 domestic dogs were tested. 11 (0.7%) of the rodents (captured in Monduli, Chunya and Masasi districts) were plague-positive. In Masasi district, 10.4% (7/67) of the rodents and 43.6% (17/39) of the dogs were positive for anti-Y. pestis IgG. It was concluded that wild and commensal rodents as well as wild and domestic small carnivores play a potential role as reservoirs and/or carriers of sylvatic plague in Tanzania, and that the disease exists in areas where human plague outbreaks have not occurred before. In order to update the distribution of the disease it is proposed that further epidemiological surveillance activities are established

The role of rodents and small carnivores in plague endemicity in Tanzania

Belgian Journal of Zoology 2005, 135 (supplement) : 119-125Between 1974 and 2003, blood samples were collected from wild and commensal rodents, and wild and domestic small carnivores in selected villages of seven districts in Tanzania that have experienced human plague outbreaks and seven districts that have not experienced any outbreak of the disease. The samples were tested for antibodies against Yersinia pestis Fraction I antigen, using passive haemagglutination (PHA) or ELISA tests. Of the 3354 rodents and 558 small carnivores from the plague infected districts, 122 (3.6%) rodents (captured in Mbulu and Lushoto districts) were plague positive; 29 (5.2%) small carnivores from Mbulu, Arumeru, Hai and Lushoto districts were plague positive, 28 of these were domestic dogs (Canis familiaris). PCR tests showed that 17.5% of 211 rodents tested from Lushoto contained Y. pestis DNA. In the non-infected districts, 1545 rodents and 171 domestic dogs were tested. 11 (0.7%) of the rodents (captured in Monduli, Chunya and Masasi districts) were plague-positive. In Masasi district, 10.4% (7/67) of the rodents and 43.6% (17/39) of the dogs were positive for anti-Y. pestis IgG. It was concluded that wild and commensal rodents as well as wild and domestic small carnivores play a potential role as reservoirs and/or carriers of sylvatic plague in Tanzania, and that the disease exists in areas where human plague outbreaks have not occurred before. In order to update the distribution of the disease it is proposed that further epidemiological surveillance activities are established