title: Microbially induced calcium carbonate precipitation: a widespread phenomenon in the biological world

authors: Seifan, Mostafa

subjects: Science & Technology

abstract: Biodeposition of minerals is a widespread phenomenon in the biological world and is mediated by bacteria, fungi, protists, and plants. Calcium carbonate is one of those minerals that naturally precipitate as a by-product of microbial metabolic activities. Over recent years, microbially induced calcium carbonate precipitation (MICP) has been proposed as a potent solution to address many environmental and engineering issues. However, for being a viable alternative to conventional techniques as well as being financially and industrially competitive, various challenges need to be overcome. In this review, the detailed metabolic pathways, including ammonification of amino acids, dissimilatory reduction of nitrate, and urea degradation (ureolysis), along with the potent bacteria and the favorable conditions for precipitation of calcium carbonate, are explained. Moreover, this review highlights the potential environmental and engineering applications of MICP, including restoration of stones and concrete, improvement of soil properties, sand consolidation, bioremediation of contaminants, and carbon dioxide sequestration. The key research and development questions necessary for near future large-scale applications of this innovative technology are also discussed.

text: Microbially induced calcium carbonate precipitation: a widespread phenomenon in the biological world Biodeposition of minerals is a widespread phenomenon in the biological world and is mediated by bacteria, fungi, protists, and plants. Calcium carbonate is one of those minerals that naturally precipitate as a by-product of microbial metabolic activities. Over recent years, microbially induced calcium carbonate precipitation (MICP) has been proposed as a potent solution to address many environmental and engineering issues. However, for being a viable alternative to conventional techniques as well as being financially and industrially competitive, various challenges need to be overcome. In this review, the detailed metabolic pathways, including ammonification of amino acids, dissimilatory reduction of nitrate, and urea degradation (ureolysis), along with the potent bacteria and the favorable conditions for precipitation of calcium carbonate, are explained. Moreover, this review highlights the potential environmental and engineering applications of MICP, including restoration of stones and concrete, improvement of soil properties, sand consolidation, bioremediation of contaminants, and carbon dioxide sequestration. The key research and development questions necessary for near future large-scale applications of this innovative technology are also discussed.

year: 2019

title: The Characteristics of New Zealand Oolong Tea

authors: Zhang, Bin

subjects: EGCG Catechins

abstract: Tea is a beverage made from steeping dried leaves in hot water. Worldwide, more than 10,000 different teas are made from different varietals of Camellia sinensis.Tea is a relatively new tea crop to New Zealand and they do grow well in New Zealand conditions. Research to date in New Zealand indicated is present some unique features compared to tea will wide. The main unique problem with New Zealand Oolong tea is the character of special colour and flavour and different process of manufacture. No systematic trials of the EGCG content had been performed on New Zealand Oolong tea and therefore this research investigated the characteristics of New Zealand Oolong tea processing and use HPLC to determine the content of EGCG in fresh tea leaves of New Zealand Oolong tea.

This study used HPLC to determine EGCG the content of leaves used to make New Zealand Oolong tea. In the fresh tea leaves that have not been through the indoor wilting stage, the content of EGCG is 124mg/g. In finished tea the content of EGCG is 112mg/g. That is significantly higher than other teas such as Pu-erh, Fujian Oolong tea, DaHongPao Black tea. 

The results indicated that the early stages of the current tea manufacturing process are critical for controlling the EGCG content and extend of EGCG oxidation in the finished product.

text: The Characteristics of New Zealand Oolong Tea Tea is a beverage made from steeping dried leaves in hot water. Worldwide, more than 10,000 different teas are made from different varietals of Camellia sinensis.Tea is a relatively new tea crop to New Zealand and they do grow well in New Zealand conditions. Research to date in New Zealand indicated is present some unique features compared to tea will wide. The main unique problem with New Zealand Oolong tea is the character of special colour and flavour and different process of manufacture. No systematic trials of the EGCG content had been performed on New Zealand Oolong tea and therefore this research investigated the characteristics of New Zealand Oolong tea processing and use HPLC to determine the content of EGCG in fresh tea leaves of New Zealand Oolong tea.

This study used HPLC to determine EGCG the content of leaves used to make New Zealand Oolong tea. In the fresh tea leaves that have not been through the indoor wilting stage, the content of EGCG is 124mg/g. In finished tea the content of EGCG is 112mg/g. That is significantly higher than other teas such as Pu-erh, Fujian Oolong tea, DaHongPao Black tea. 

The results indicated that the early stages of the current tea manufacturing process are critical for controlling the EGCG content and extend of EGCG oxidation in the finished product.

year: 2012

title: Mental health of people of diverse genders and sexualities in Aotearoa/New Zealand: Findings from the New Zealand Mental Health Monitor

authors: Tan, Kyle K. H.

subjects: Science & Technology

abstract: Issues addressed: To examine mental health inequities, and social exclusion and isolation and protective factor differences between people of diverse genders and sexualities (lesbian/gay, bisexual, gender diverse, and takatāpui) and cisgender and heterosexual people in Aotearoa/New Zealand.  Methods: We employed data from the pooled probability sample of 2016 and 2018 New Zealand Mental Health Monitor. The sample comprised of 2,938 people at least 15 years old, of which 93 had diverse gender and sexuality identities. Generalised linear models were used to test for differences in mental health (current and lifetime mental distress, depression, anxiety, self-harm and suicide), social exclusion and isolation, and friend and family support for people of diverse genders and sexualities. We also conducted exploratory linear regression analyses to examine whether mental health difficulties were associated with social exclusion and isolation and friend/family support.  Results: People of diverse genders and sexualities had high rates of mental health difficulties across all variables we examined. For example, people identifying as diverse genders and sexualities had three times the risk of considering self-harm and suicide than their cisgender and heterosexual counterparts (22% vs 5%; RR = 3.12). People of diverse genders and sexualities also scored an average of 6.08 points higher on the 27-point PHQ-9 depression scale when they had experienced social isolation, and 4.01 points higher when they experienced social exclusion. Conclusion: Our results are consistent with current literature on the large mental health inequities faced by people of diverse genders and sexualities.  So what?: Policy makers and healthcare providers in Aotearoa/New Zealand should consider the negative mental health consequences of social exclusion and isolation for people of diverse genders and sexualities.

text: Mental health of people of diverse genders and sexualities in Aotearoa/New Zealand: Findings from the New Zealand Mental Health Monitor Issues addressed: To examine mental health inequities, and social exclusion and isolation and protective factor differences between people of diverse genders and sexualities (lesbian/gay, bisexual, gender diverse, and takatāpui) and cisgender and heterosexual people in Aotearoa/New Zealand.  Methods: We employed data from the pooled probability sample of 2016 and 2018 New Zealand Mental Health Monitor. The sample comprised of 2,938 people at least 15 years old, of which 93 had diverse gender and sexuality identities. Generalised linear models were used to test for differences in mental health (current and lifetime mental distress, depression, anxiety, self-harm and suicide), social exclusion and isolation, and friend and family support for people of diverse genders and sexualities. We also conducted exploratory linear regression analyses to examine whether mental health difficulties were associated with social exclusion and isolation and friend/family support.  Results: People of diverse genders and sexualities had high rates of mental health difficulties across all variables we examined. For example, people identifying as diverse genders and sexualities had three times the risk of considering self-harm and suicide than their cisgender and heterosexual counterparts (22% vs 5%; RR = 3.12). People of diverse genders and sexualities also scored an average of 6.08 points higher on the 27-point PHQ-9 depression scale when they had experienced social isolation, and 4.01 points higher when they experienced social exclusion. Conclusion: Our results are consistent with current literature on the large mental health inequities faced by people of diverse genders and sexualities.  So what?: Policy makers and healthcare providers in Aotearoa/New Zealand should consider the negative mental health consequences of social exclusion and isolation for people of diverse genders and sexualities.

year: 2021-10-03