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Tropical forests play a key role in climate change mitigation. Recovering, degraded and secondary forests are becoming more dominant in tropical landscapes and yet large uncertainties exist regarding their carbon sink and storage. Remote sensing data enables a spatially and temporally explicit assessment of forests that can improve the accuracy of forest carbon flux estimates. This thesis uses a variety of satellite datasets to improve the spatial representation of the carbon sink in recovering forests. By combining satellite-based datasets of secondary forest age and aboveground carbon, the carbon accumulation was modelled across the Brazilian Amazon. Environmental variables and disturbances were found to drive spatially distinct regrowth patterns, with repeated anthropogenic disturbances reducing regrowth by up to 55%. Carbon recovery in degraded and secondary forests was then modelled across the Amazon, Central Africa, and Borneo. Between 1984 and 2018 recovering forests offset a quarter of carbon emissions from tropical forest loss, indicating the mitigation potential of protecting them, alongside old-growth forest conservation. Uncertainties in estimating the net global anthropogenic greenhouse gas flux from the entire land-use sector are reflected in the difference of 4-7GtCO2eyr-1 between methodological approaches, that has largely been attributed to managed forest fluxes in the tropics. This ‘gap’ represents a challenge within the Global Stocktake when emissions-reductions progress will be evaluated. This thesis demonstrates how to adjust remote sensing-based estimates of forest carbon fluxes to align them with national greenhouse gas inventory approaches, making them useful tools for Monitoring Reporting and Verification. Knowing how secondary forests are identified, and how associated carbon fluxes are incorporated into respective approaches are key to reconciling differences. Overall, this research uses remote sensing datasets t

Wind turbines and power lines can cause bird mortality due to collision or electrocution. The biodiversity impacts of energy infrastructure (EI) can be minimised through effective landscape-scale planning and mitigation. The identification of high-vulnerability areas is urgently needed to assess potential cumulative impacts of EI while supporting the transition to zero carbon energy. We collected GPS location data from 1,454 birds from 27 species susceptible to collision within Europe and North Africa and identified areas where tracked birds are most at risk of colliding with existing EI. Sensitivity to EI development was estimated for wind turbines and power lines by calculating the proportion of GPS flight locations at heights where birds were at risk of collision and accounting for species' specific susceptibility to collision. We mapped the maximum collision sensitivity value obtained across all species, in each 5 × 5 km grid cell, across Europe and North Africa. Vulnerability to collision was obtained by overlaying the sensitivity surfaces with density of wind turbines and transmission power lines. Results: Exposure to risk varied across the 27 species, with some species flying consistently at heights where they risk collision. For areas with sufficient tracking data within Europe and North Africa, 13.6% of the area was classified as high sensitivity to wind turbines and 9.4% was classified as high sensitivity to transmission power lines. Sensitive areas were concentrated within important migratory corridors and along coastlines. Hotspots of vulnerability to collision with wind turbines and transmission power lines (2018 data) were scattered across the study region with highest concentrations occurring in central Europe, near the strait of Gibraltar and the Bosporus in Turkey. Synthesis and applications. We identify the areas of Europe and North Africa that are most sensitive for the specific populations of birds for which sufficient GPS tracking data at hig

Wind turbines and power lines can cause bird mortality due to collision or electrocution. The biodiversity impacts of energy infrastructure (EI) can be minimised through effective landscape-scale planning and mitigation. The identification of high-vulnerability areas is urgently needed to assess potential cumulative impacts of EI while supporting the transition to zero carbon energy. We collected GPS location data from 1,454 birds from 27 species susceptible to collision within Europe and North Africa and identified areas where tracked birds are most at risk of colliding with existing EI. Sensitivity to EI development was estimated for wind turbines and power lines by calculating the proportion of GPS flight locations at heights where birds were at risk of collision and accounting for species' specific susceptibility to collision. We mapped the maximum collision sensitivity value obtained across all species, in each 5 x 5 km grid cell, across Europe and North Africa. Vulnerability to collision was obtained by overlaying the sensitivity surfaces with density of wind turbines and transmission power lines. Results: Exposure to risk varied across the 27 species, with some species flying consistently at heights where they risk collision. For areas with sufficient tracking data within Europe and North Africa, 13.6% of the area was classified as high sensitivity to wind turbines and 9.4% was classified as high sensitivity to transmission power lines. Sensitive areas were concentrated within important migratory corridors and along coastlines. Hotspots of vulnerability to collision with wind turbines and transmission power lines (2018 data) were scattered across the study region with highest concentrations occurring in central Europe, near the strait of Gibraltar and the Bosporus in Turkey. Synthesis and applications. We identify the areas of Europe and North Africa that are most sensitive for the specific populations of birds for which sufficient GPS tracking data at high s

Wind turbines and power lines can cause bird mortality due to collision or electrocution. The biodiversity impacts of energy infrastructure (EI) can be minimised through effective landscape-scale planning and mitigation. The identification of high-vulnerability areas is urgently needed to assess potential cumulative impacts of EI while supporting the transition to zero carbon energy. We collected GPS location data from 1,454 birds from 27 species susceptible to collision within Europe and North Africa and identified areas where tracked birds are most at risk of colliding with existing EI. Sensitivity to EI development was estimated for wind turbines and power lines by calculating the proportion of GPS flight locations at heights where birds were at risk of collision and accounting for species' specific susceptibility to collision. We mapped the maximum collision sensitivity value obtained across all species, in each 5 x 5 km grid cell, across Europe and North Africa. Vulnerability to collision was obtained by overlaying the sensitivity surfaces with density of wind turbines and transmission power lines. Results: Exposure to risk varied across the 27 species, with some species flying consistently at heights where they risk collision. For areas with sufficient tracking data within Europe and North Africa, 13.6% of the area was classified as high sensitivity to wind turbines and 9.4% was classified as high sensitivity to transmission power lines. Sensitive areas were concentrated within important migratory corridors and along coastlines. Hotspots of vulnerability to collision with wind turbines and transmission power lines (2018 data) were scattered across the study region with highest concentrations occurring in central Europe, near the strait of Gibraltar and the Bosporus in Turkey. Synthesis and applications. We identify the areas of Europe and North Africa that are most sensitive for the specific populations of birds for which sufficient GPS tracking data at high s

Wind turbines and power lines can cause bird mortality due to collision or electrocution. The biodiversity impacts of energy infrastructure (EI) can be minimised through effective landscape-scale planning and mitigation. The identification of high-vulnerability areas is urgently needed to assess potential cumulative impacts of EI while supporting the transition to zero carbon energy. We collected GPS location data from 1,454 birds from 27 species susceptible to collision within Europe and North Africa and identified areas where tracked birds are most at risk of colliding with existing EI. Sensitivity to EI development was estimated for wind turbines and power lines by calculating the proportion of GPS flight locations at heights where birds were at risk of collision and accounting for species' specific susceptibility to collision. We mapped the maximum collision sensitivity value obtained across all species, in each 5 x 5 km grid cell, across Europe and North Africa. Vulnerability to collision was obtained by overlaying the sensitivity surfaces with density of wind turbines and transmission power lines. Results: Exposure to risk varied across the 27 species, with some species flying consistently at heights where they risk collision. For areas with sufficient tracking data within Europe and North Africa, 13.6% of the area was classified as high sensitivity to wind turbines and 9.4% was classified as high sensitivity to transmission power lines. Sensitive areas were concentrated within important migratory corridors and along coastlines. Hotspots of vulnerability to collision with wind turbines and transmission power lines (2018 data) were scattered across the study region with highest concentrations occurring in central Europe, near the strait of Gibraltar and the Bosporus in Turkey. Synthesis and applications. We identify the areas of Europe and North Africa that are most sensitive for the specific populations of birds for which sufficient GPS tracking data at high s

Wind turbines and power lines can cause bird mortality due to collision or electrocution. The biodiversity impacts of energy infrastructure (EI) can be minimised through effective landscape-scale planning and mitigation. The identification of high-vulnerability areas is urgently needed to assess potential cumulative impacts of EI while supporting the transition to zero carbon energy. We collected GPS location data from 1,454 birds from 27 species susceptible to collision within Europe and North Africa and identified areas where tracked birds are most at risk of colliding with existing EI. Sensitivity to EI development was estimated for wind turbines and power lines by calculating the proportion of GPS flight locations at heights where birds were at risk of collision and accounting for species' specific susceptibility to collision. We mapped the maximum collision sensitivity value obtained across all species, in each 5 x 5 km grid cell, across Europe and North Africa. Vulnerability to collision was obtained by overlaying the sensitivity surfaces with density of wind turbines and transmission power lines. Results: Exposure to risk varied across the 27 species, with some species flying consistently at heights where they risk collision. For areas with sufficient tracking data within Europe and North Africa, 13.6% of the area was classified as high sensitivity to wind turbines and 9.4% was classified as high sensitivity to transmission power lines. Sensitive areas were concentrated within important migratory corridors and along coastlines. Hotspots of vulnerability to collision with wind turbines and transmission power lines (2018 data) were scattered across the study region with highest concentrations occurring in central Europe, near the strait of Gibraltar and the Bosporus in Turkey. Synthesis and applications. We identify the areas of Europe and North Africa that are most sensitive for the specific populations of birds for which sufficient GPS tracking data at high s

Wind turbines and power lines can cause bird mortality due to collision or electrocution. The biodiversity impacts of energy infrastructure (EI) can be minimised through effective landscape-scale planning and mitigation. The identification of high-vulnerability areas is urgently needed to assess potential cumulative impacts of EI while supporting the transition to zero carbon energy. We collected GPS location data from 1,454 birds from 27 species susceptible to collision within Europe and North Africa and identified areas where tracked birds are most at risk of colliding with existing EI. Sensitivity to EI development was estimated for wind turbines and power lines by calculating the proportion of GPS flight locations at heights where birds were at risk of collision and accounting for species' specific susceptibility to collision. We mapped the maximum collision sensitivity value obtained across all species, in each 5 × 5 km grid cell, across Europe and North Africa. Vulnerability to collision was obtained by overlaying the sensitivity surfaces with density of wind turbines and transmission power lines. Results: Exposure to risk varied across the 27 species, with some species flying consistently at heights where they risk collision. For areas with sufficient tracking data within Europe and North Africa, 13.6% of the area was classified as high sensitivity to wind turbines and 9.4% was classified as high sensitivity to transmission power lines. Sensitive areas were concentrated within important migratory corridors and along coastlines. Hotspots of vulnerability to collision with wind turbines and transmission power lines (2018 data) were scattered across the study region with highest concentrations occurring in central Europe, near the strait of Gibraltar and the Bosporus in Turkey. Synthesis and applications. We identify the areas of Europe and North Africa that are most sensitive for the specific populations of birds for which sufficient GPS tracking data at hig

Wind turbines and power lines can cause bird mortality due to collision or electrocution. The biodiversity impacts of energy infrastructure (EI) can be minimised through effective landscape-scale planning and mitigation. The identification of high-vulnerability areas is urgently needed to assess potential cumulative impacts of EI while supporting the transition to zero carbon energy. We collected GPS location data from 1,454 birds from 27 species susceptible to collision within Europe and North Africa and identified areas where tracked birds are most at risk of colliding with existing EI. Sensitivity to EI development was estimated for wind turbines and power lines by calculating the proportion of GPS flight locations at heights where birds were at risk of collision and accounting for species' specific susceptibility to collision. We mapped the maximum collision sensitivity value obtained across all species, in each 5 x 5 km grid cell, across Europe and North Africa. Vulnerability to collision was obtained by overlaying the sensitivity surfaces with density of wind turbines and transmission power lines. Results: Exposure to risk varied across the 27 species, with some species flying consistently at heights where they risk collision. For areas with sufficient tracking data within Europe and North Africa, 13.6% of the area was classified as high sensitivity to wind turbines and 9.4% was classified as high sensitivity to transmission power lines. Sensitive areas were concentrated within important migratory corridors and along coastlines. Hotspots of vulnerability to collision with wind turbines and transmission power lines (2018 data) were scattered across the study region with highest concentrations occurring in central Europe, near the strait of Gibraltar and the Bosporus in Turkey. Synthesis and applications. We identify the areas of Europe and North Africa that are most sensitive for the specific populations of birds for which sufficient GPS tracking data at high s

A fundamental question is how autophagosome formation is regulated. Here we show that the PX domain protein HS1BP3 is a negative regulator of autophagosome formation. HS1BP3 depletion increased the formation of LC3-positive autophagosomes and degradation of cargo both in human cell culture and in zebrafish. HS1BP3 is localized to ATG16L1-and ATG9-positive autophagosome precursors and we show that HS1BP3 binds phosphatidic acid (PA) through its PX domain. Furthermore, we find the total PA content of cells to be significantly upregulated in the absence of HS1BP3, as a result of increased activity of the PA-producing enzyme phospholipase D (PLD) and increased localization of PLD1 to ATG16L1-positive membranes. We propose that HS1BP3 regulates autophagy by modulating the PA content of the ATG16L1-positive autophagosome precursor membranes through PLD1 activity and localization. Our findings provide key insights into how autophagosome formation is regulated by a novel negative-feedback mechanism on membrane lipids.

A fundamental question is how autophagosome formation is regulated. Here we show that the PX domain protein HS1BP3 is a negative regulator of autophagosome formation. HS1BP3 depletion increased the formation of LC3-positive autophagosomes and degradation of cargo both in human cell culture and in zebrafish. HS1BP3 is localized to ATG16L1-and ATG9-positive autophagosome precursors and we show that HS1BP3 binds phosphatidic acid (PA) through its PX domain. Furthermore, we find the total PA content of cells to be significantly upregulated in the absence of HS1BP3, as a result of increased activity of the PA-producing enzyme phospholipase D (PLD) and increased localization of PLD1 to ATG16L1-positive membranes. We propose that HS1BP3 regulates autophagy by modulating the PA content of the ATG16L1-positive autophagosome precursor membranes through PLD1 activity and localization. Our findings provide key insights into how autophagosome formation is regulated by a novel negative-feedback mechanism on membrane lipids.

A fundamental question is how autophagosome formation is regulated. Here we show that the PX domain protein HS1BP3 is a negative regulator of autophagosome formation. HS1BP3 depletion increased the formation of LC3-positive autophagosomes and degradation of cargo both in human cell culture and in zebrafish. HS1BP3 is localized to ATG16L1-and ATG9-positive autophagosome precursors and we show that HS1BP3 binds phosphatidic acid (PA) through its PX domain. Furthermore, we find the total PA content of cells to be significantly upregulated in the absence of HS1BP3, as a result of increased activity of the PA-producing enzyme phospholipase D (PLD) and increased localization of PLD1 to ATG16L1-positive membranes. We propose that HS1BP3 regulates autophagy by modulating the PA content of the ATG16L1-positive autophagosome precursor membranes through PLD1 activity and localization. Our findings provide key insights into how autophagosome formation is regulated by a novel negative-feedback mechanism on membrane lipids.

A fundamental question is how autophagosome formation is regulated. Here we show that the PX domain protein HS1BP3 is a negative regulator of autophagosome formation. HS1BP3 depletion increased the formation of LC3-positive autophagosomes and degradation of cargo both in human cell culture and in zebrafish. HS1BP3 is localized to ATG16L1-and ATG9-positive autophagosome precursors and we show that HS1BP3 binds phosphatidic acid (PA) through its PX domain. Furthermore, we find the total PA content of cells to be significantly upregulated in the absence of HS1BP3, as a result of increased activity of the PA-producing enzyme phospholipase D (PLD) and increased localization of PLD1 to ATG16L1-positive membranes. We propose that HS1BP3 regulates autophagy by modulating the PA content of the ATG16L1-positive autophagosome precursor membranes through PLD1 activity and localization. Our findings provide key insights into how autophagosome formation is regulated by a novel negative-feedback mechanism on membrane lipids.

Severe burn injury significantly affects cardiovascular function for up to 3 years. However, whether this leads to long-term pathology is unknown. The impact of non-severe burn injury, which accounts for over 80% of admissions in developed countries, has not been investigated. Using a rodent model of non-severe burn injury with subsequent echocardiography we showed significantly increased left ventricular end systolic diameter (LVESD) and ventricular wall thickness at up to 3 months post-injury. Use of propranolol abrogated the changes in cardiac measures observed. Subsequently we investigated changes in a patient cohort with non-severe injury. Echocardiography measured at baseline and at 3 months post-injury showed increased LVESD at 3 months and significantly decreased posterior wall diameter. Finally, 32 years of Western Australian hospital records were used to investigate the incidence of cardiovascular disease admissions after burn injury. People who had experienced a burn had increased hospital admissions and length of stay for cardiovascular diseases when compared to a matched uninjured cohort. This study presents animal, patient and population data that strongly suggest non-severe burn injury has significant effects on cardiovascular function and long-term morbidity in some burn patients. Identification of patients at risk will promote better intervention and outcomes for burn patients.

A fundamental question is how autophagosome formation is regulated. Here we show that the PX domain protein HS1BP3 is a negative regulator of autophagosome formation. HS1BP3 depletion increased the formation of LC3-positive autophagosomes and degradation of cargo both in human cell culture and in zebrafish. HS1BP3 is localized to ATG16L1-and ATG9-positive autophagosome precursors and we show that HS1BP3 binds phosphatidic acid (PA) through its PX domain. Furthermore, we find the total PA content of cells to be significantly upregulated in the absence of HS1BP3, as a result of increased activity of the PA-producing enzyme phospholipase D (PLD) and increased localization of PLD1 to ATG16L1-positive membranes. We propose that HS1BP3 regulates autophagy by modulating the PA content of the ATG16L1-positive autophagosome precursor membranes through PLD1 activity and localization. Our findings provide key insights into how autophagosome formation is regulated by a novel negative-feedback mechanism on membrane lipids.

provided by author, The purpose of this study was to investigate factors that contribute to boys dropping out of secondary schools in the Khomas Region. According to statistical reports of the Educational Management Information System (EMIS) Education Statistics at the Ministry of Education, on average, early school leaving is a greater problem among male learners than among female learners. This is an exception only in two regions. Another aim was to identify the needs which are specific to the education of boys and what could be done to increase retention of boys in secondary schools. A qualitative case study approach was used for this study. The population comprised of secondary school teachers, principals and boys, including those who have dropped out of school, in the Khomas Region. The following purposeful sampling strategies were employed to obtain the sample: stratified purposeful sampling, convenience sampling, and purposeful random sampling. The sample consisted of the following stratified purposeful sub-samples: five principals by virtue of their positions as managers of schools, five most experienced teachers, five focus groups of boys currently in school, one group per school and 25 boys who had dropped out of school (five boys who had dropped out per school). Document analysis and semistructured interviews were used as data collection instruments. The results revealed that there are several factors that influence boys to drop out of school. These range from the individual, family, school and community related factors. The top most factors that were identified as contributing towards boys. dropping out of school are: poor parental support in both academic and social lives of boys, peer pressure and failure on the part of boys to value and appreciate education at their age

provided by author, The purpose of this study was to investigate factors that contribute to boys dropping out of secondary schools in the Khomas Region. According to statistical reports of the Educational Management Information System (EMIS) Education Statistics at the Ministry of Education, on average, early school leaving is a greater problem among male learners than among female learners. This is an exception only in two regions. Another aim was to identify the needs which are specific to the education of boys and what could be done to increase retention of boys in secondary schools. A qualitative case study approach was used for this study. The population comprised of secondary school teachers, principals and boys, including those who have dropped out of school, in the Khomas Region. The following purposeful sampling strategies were employed to obtain the sample: stratified purposeful sampling, convenience sampling, and purposeful random sampling. The sample consisted of the following stratified purposeful sub-samples: five principals by virtue of their positions as managers of schools, five most experienced teachers, five focus groups of boys currently in school, one group per school and 25 boys who had dropped out of school (five boys who had dropped out per school). Document analysis and semistructured interviews were used as data collection instruments. The results revealed that there are several factors that influence boys to drop out of school. These range from the individual, family, school and community related factors. The top most factors that were identified as contributing towards boys. dropping out of school are: poor parental support in both academic and social lives of boys, peer pressure and failure on the part of boys to value and appreciate education at their age

provided by author, The purpose of this study was to investigate factors that contribute to boys dropping out of secondary schools in the Khomas Region. According to statistical reports of the Educational Management Information System (EMIS) Education Statistics at the Ministry of Education, on average, early school leaving is a greater problem among male learners than among female learners. This is an exception only in two regions. Another aim was to identify the needs which are specific to the education of boys and what could be done to increase retention of boys in secondary schools. A qualitative case study approach was used for this study. The population comprised of secondary school teachers, principals and boys, including those who have dropped out of school, in the Khomas Region. The following purposeful sampling strategies were employed to obtain the sample: stratified purposeful sampling, convenience sampling, and purposeful random sampling. The sample consisted of the following stratified purposeful sub-samples: five principals by virtue of their positions as managers of schools, five most experienced teachers, five focus groups of boys currently in school, one group per school and 25 boys who had dropped out of school (five boys who had dropped out per school). Document analysis and semistructured interviews were used as data collection instruments. The results revealed that there are several factors that influence boys to drop out of school. These range from the individual, family, school and community related factors. The top most factors that were identified as contributing towards boys. dropping out of school are: poor parental support in both academic and social lives of boys, peer pressure and failure on the part of boys to value and appreciate education at their age

provided by author, The purpose of this study was to investigate factors that contribute to boys dropping out of secondary schools in the Khomas Region. According to statistical reports of the Educational Management Information System (EMIS) Education Statistics at the Ministry of Education, on average, early school leaving is a greater problem among male learners than among female learners. This is an exception only in two regions. Another aim was to identify the needs which are specific to the education of boys and what could be done to increase retention of boys in secondary schools. A qualitative case study approach was used for this study. The population comprised of secondary school teachers, principals and boys, including those who have dropped out of school, in the Khomas Region. The following purposeful sampling strategies were employed to obtain the sample: stratified purposeful sampling, convenience sampling, and purposeful random sampling. The sample consisted of the following stratified purposeful sub-samples: five principals by virtue of their positions as managers of schools, five most experienced teachers, five focus groups of boys currently in school, one group per school and 25 boys who had dropped out of school (five boys who had dropped out per school). Document analysis and semistructured interviews were used as data collection instruments. The results revealed that there are several factors that influence boys to drop out of school. These range from the individual, family, school and community related factors. The top most factors that were identified as contributing towards boys. dropping out of school are: poor parental support in both academic and social lives of boys, peer pressure and failure on the part of boys to value and appreciate education at their age

provided by author, The purpose of this study was to investigate factors that contribute to boys dropping out of secondary schools in the Khomas Region. According to statistical reports of the Educational Management Information System (EMIS) Education Statistics at the Ministry of Education, on average, early school leaving is a greater problem among male learners than among female learners. This is an exception only in two regions. Another aim was to identify the needs which are specific to the education of boys and what could be done to increase retention of boys in secondary schools. A qualitative case study approach was used for this study. The population comprised of secondary school teachers, principals and boys, including those who have dropped out of school, in the Khomas Region. The following purposeful sampling strategies were employed to obtain the sample: stratified purposeful sampling, convenience sampling, and purposeful random sampling. The sample consisted of the following stratified purposeful sub-samples: five principals by virtue of their positions as managers of schools, five most experienced teachers, five focus groups of boys currently in school, one group per school and 25 boys who had dropped out of school (five boys who had dropped out per school). Document analysis and semistructured interviews were used as data collection instruments. The results revealed that there are several factors that influence boys to drop out of school. These range from the individual, family, school and community related factors. The top most factors that were identified as contributing towards boys. dropping out of school are: poor parental support in both academic and social lives of boys, peer pressure and failure on the part of boys to value and appreciate education at their age

Secreted frizzled-related protein 4 (sFRP4) is a Wnt signaling antagonist. Classically, sFRP4 antagonizes the canonical Wnt signaling pathway, resulting in decreased cellular proliferation and increased apoptosis. Recent research from our laboratory has established that sFRP4 inhibits angiogenesis by decreasing proliferation, migration, and tube formation of endothelial cells. The objective of this study was to examine the role of sFRP4’s cysteine-rich domain (CRD) and netrin-like domain (NLD) in angiogenesis inhibition. Experiments were carried out to examine cell death and tube formation of endothelial cells after treatment with the CRD and the NLD. The CRD was seen to inhibit tube formation of endothelial cells, which suggests that this domain is important to sFRP4’s antiangiogenesis property. In addition, the NLD promoted endothelial cell death and may also inhibit angiogenesis. Furthermore, treatment with the CRD and the NLD increased endothelial intracellular calcium levels. Our findings implicate a role for both the CRD and NLD in angiogenesis inhibition by sFRP4. It is suggestive of alternative antiangiogenic downstream targets of canonical Wnt signaling and a possible importance of the noncanonical Ca2+ Wnt signaling pathway in sFRP4-mediated angiogenesis inhibition.

provided by author, The purpose of this study was to investigate factors that contribute to boys dropping out of secondary schools in the Khomas Region. According to statistical reports of the Educational Management Information System (EMIS) Education Statistics at the Ministry of Education, on average, early school leaving is a greater problem among male learners than among female learners. This is an exception only in two regions. Another aim was to identify the needs which are specific to the education of boys and what could be done to increase retention of boys in secondary schools. A qualitative case study approach was used for this study. The population comprised of secondary school teachers, principals and boys, including those who have dropped out of school, in the Khomas Region. The following purposeful sampling strategies were employed to obtain the sample: stratified purposeful sampling, convenience sampling, and purposeful random sampling. The sample consisted of the following stratified purposeful sub-samples: five principals by virtue of their positions as managers of schools, five most experienced teachers, five focus groups of boys currently in school, one group per school and 25 boys who had dropped out of school (five boys who had dropped out per school). Document analysis and semistructured interviews were used as data collection instruments. The results revealed that there are several factors that influence boys to drop out of school. These range from the individual, family, school and community related factors. The top most factors that were identified as contributing towards boys. dropping out of school are: poor parental support in both academic and social lives of boys, peer pressure and failure on the part of boys to value and appreciate education at their age

Wnt signaling is involved in developmental processes, cell proliferation, and cell migration. Secreted frizzled-related protein 4 (sFRP4) has been demonstrated to be a Wnt antagonist; however, its effects on endothelial cell migration and angiogenesis have not yet been reported. Using various in vitro assays, we show that sFRP4 inhibits endothelial cell migration and the development of sprouts and pseudopodia as well as disrupts the stability of endothelial rings in addition to inhibiting proliferation. sFRP4 interfered with endothelial cell functions by antagonizing the canonical Wnt/ß-catenin signaling pathway and the Wnt/planar cell polarity pathway. Furthermore, sFRP4 blocked the effect of vascular endothelial growth factor on endothelial cells. sFRP4 also selectively induced apoptotic events in endothelial cells by increasing cellular levels of reactive oxygen species. In vivo assays demonstrated a reduction in vascularity after sFRP4 treatment. Most importantly, sFRP4 restricted tumor growth in mice by interfering with endothelial cell function. The data demonstrate sFRP4 to be a potent angiogenesis inhibitor that warrants further investigation as a therapeutic agent in the control of angiogenesis-associated pathology. Copyright © American Society for Investigative Pathology.

We have shown previously that exposure of guinea pig ventricular myocytes to 30 μM hydrogen peroxide (H2O2) for 5 min followed by 10 U/ml catalase to degrade the H2O2 results in a persistent increase in superoxide production by the mitochondria. This leads to a 2-fold increase in protein synthesis measured as [3H] leucine incorporation. We characterised the effect of a transient exposure of cardiac myocytes to H2O2 on the proteome. Myocytes were exposed to 0 μM or 30 μM H2O2 for 5 min followed by 10U/ml catalase. Protein was extracted, labelled with iTRAQ reagents and the peptides were analysed by LC–MALDI-TOF/TOF mass spectrometry and identified against SwissProt and Ludwig NR databases. More than 900 proteins were identified. Transient exposure of the myocytes to H2O2 resulted in altered expression of 62 proteins. 40% of proteins identified with altered expression were mitochondrial. Consistent with our in vitro data, mitochondria complex I and complex III subunit expression was upregulated while downregulation of complex IV and ATP synthase subunits suggested compromised ATP production. We also detected an increase in sarcomere associated proteins including Troponin C, Tropomyosin I alpha isoform 6 and Myosin light chain 2 and 3. Prohibitin was downregulated and calcireticulin expression was upregulated, consistent with promotion of cellular growth. We are currently validating the findings with in vitro functional studies in the myocytes. These data suggest that transient exposure to cardiac myocytes is sufficient to significantly alter expression of proteins and provides insight into early mechanisms of development of cardiac hypertrophy.

The Biospecialties Branch, MRMPB, 6570 Aerospace Medical Research Laboratories, initiated a research effort to support and supplement the Air Force Aeronautical Systems Division program concerned with the relationship of microbial contamination to deleterious changes in JP-4 fuel systems. Results of this program have shown the following: the majority of JP-4 fuel systems contain low levels of viable microorganisms; microorganisms are primarily associated with the water phase and rarely with the fuel phase of a JP-4 fuel/water system; JP-fuels exert a toxic effect on viable microbial cells; and microbial corrosion of aluminum alloys 7075 2024, and 7178 can occur in the laboratory but does not appear to be the major cause of corrosion in operational systems. Twenty percent ethylene glycol monomethyl ether (EGME) in a laboratory JP-4 fuel/water-bottom acts as an inhibitor to the majority of viable cells present. As a result of engineering design, it is possible that fuel capacitance probes can cease to operate as a result of microbial growth. Micronic filter materials of phenolformaldehyde impregnated paper can support the growth of microorganisms, but growth even after 43 days is insufficient to cause filter clogging, provided the filter is immersed in fuel. In addition, field surveys of JP-4 fuel handling facilities and aircraft have shown that improved housekeeping and the use of EGME have reduced the quantity of microbial contaminants initially found in the jet systems to an insignificant level., Prepared in cooperation with University of Dayton, Research Inst., Dayton, Ohio