title: Who goes to a sexual health clinic? Gender differences in service utilisation.

authors: Morgan, Jane

subjects: sexual health

abstract: Aim: Our aim was to review utilisation of the Hamilton Sexual Health Clinic
(Hamilton, Waikato, New Zealand) with regard to gender differences.
Methods: Notes of those attending during 9 months (1 February 2008–31 October
2008) were reviewed—and their demographic details, source of referral, reasons for
attending, and diagnostic coding data were compared. In addition, Waikato Hospital
laboratory provided Chlamydia trachomatis test results for the study period. Data was
analysed for gender differences.
Results: Overall, more women attended than men. By age bands, more 15–19 year old
women than men attended (23.3% vs 12.5%, p<0.001) but, for all age-bands 20 years
and older, men were at least as likely to attend as women. Further, for those aged 25–
29 years (20.3% vs 17%, p<0.5) and 45 years and older (11.9% vs 7.4%, p<0.001),
more men than women of the same-age band were seen. Men who attended were
more likely to self-refer (58.5% vs 43%, p<0.001) and less likely to be asymptomatic
(30.3% vs 38.4%, p<0.001).
Conclusions: Our data suggest men aged 20 years and older are at least, if not more,
likely than women to attend a sexual health clinic for sexual health concerns.
However, there appears to be under-utilisation by younger men. To improve sexual
health for men and women, help-seeking must be timely and effective. We need to
better understand and address sexual healthcare barriers for young men.

text: Who goes to a sexual health clinic? Gender differences in service utilisation. Aim: Our aim was to review utilisation of the Hamilton Sexual Health Clinic
(Hamilton, Waikato, New Zealand) with regard to gender differences.
Methods: Notes of those attending during 9 months (1 February 2008–31 October
2008) were reviewed—and their demographic details, source of referral, reasons for
attending, and diagnostic coding data were compared. In addition, Waikato Hospital
laboratory provided Chlamydia trachomatis test results for the study period. Data was
analysed for gender differences.
Results: Overall, more women attended than men. By age bands, more 15–19 year old
women than men attended (23.3% vs 12.5%, p<0.001) but, for all age-bands 20 years
and older, men were at least as likely to attend as women. Further, for those aged 25–
29 years (20.3% vs 17%, p<0.5) and 45 years and older (11.9% vs 7.4%, p<0.001),
more men than women of the same-age band were seen. Men who attended were
more likely to self-refer (58.5% vs 43%, p<0.001) and less likely to be asymptomatic
(30.3% vs 38.4%, p<0.001).
Conclusions: Our data suggest men aged 20 years and older are at least, if not more,
likely than women to attend a sexual health clinic for sexual health concerns.
However, there appears to be under-utilisation by younger men. To improve sexual
health for men and women, help-seeking must be timely and effective. We need to
better understand and address sexual healthcare barriers for young men.

year: 2008-12

title: Soil carbon loss under pasture and pine: Responses to urine addition

authors: Lambie, Suzanne Margaret

subjects: Urine

abstract: There have been reports of losses of soil carbon (C) in New Zealand pastures under dairy grazing.  Acceleration of mineralisation or leaching of soil C following urine deposition may decrease soil C.  However, little research of the effect of cow urine on soil C has been conducted.  The overall objective of this thesis was to investigate the potential for dairy cow urine to solubilise soil C, which can then be lost through mineralisation or leaching.  Soils from both grazed pasture and Pinus radiata plantations (termed pasture and pine soils) were investigated.

The concentration, composition, and bioavailability of urine-C were investigated.  Cow urine contained 7.5±1.2 g C L–¹, with a C:N ratio of 2:1.  About 45% of the C content of cow urine was attributed to hippuric acid, the other major contributors were urea, an unidentified amide and phenaceturic acid.  On incubation at 25°C, up to 25% of urine-C was degraded in 28 days, demonstrating that cow urine is biodegradable and could potentially act to prime C mineralisation in soils.  

Solubilisation of soil C (0-20 cm soil depth) following urine application was tested by measuring adsorption of urine-C and subsequent desorption of soil C in air-dried pine and pasture soils.  While adsorption was low at 3% of urine-C, the solubilisation of soil C by urine ranged between 11-28% of soil C concentration for 5 different soils, however, solubilisation was likely overestimated due to the use of air-dried soils.  Soil C solubilisation was also measured in field moist soils applied with artificial urine, and was less than that reported from air-dried soils.  

Priming of soil C mineralisation, solubilisation, and extracellular enzyme activity were measured using moist repacked pine and pasture soil cores (0-5 cm soil depth) treated with cow urine or radio-labelled artificial urine.  Positive priming of soil C mineralisation, where more carbon dioxide (CO₂) was produced than C added, was measured following application of cow urine in both pine and pasture soils.  The pasture soils lost 5.1±0.9%, and the pine soils 4.0±0.1%, of soil C concentration as CO₂ during a 84 day incubation.  Positive priming was attributed to increased microbial and urease activity and accelerated soil C mineralisation in urine treated soils.  The remaining extracellular enzyme activities assayed were unlikely to have contributed to soil C priming.  In contrast to the positive priming measured following cow urine application, treatment of soil with artificial urine resulted in less CO₂ produced than C added – or negative priming.  Increased soil pH following urine application may have played an important role in increasing C mineralisation as water soluble C increased with increasing soil pH.  Therefore, cow urine can cause priming of soil C mineralisation and lead to a loss of soil C.  However, artificial urine may not adequately model cow urine with respect to C cycling.

Soil C solubilisation by urine and subsequent leaching from undisturbed pasture soil (0-5 cm soil depth) was assessed by applying δ¹³C enriched urine.  Leaching resulted in a loss of 0.45±0.03% of soil C concentration, which was 10 times greater than the loss of soil C in the water control treatment (0.048±0.001%).  The leaching of soil C was small compared to the 5% loss of soil C by priming in the repacked core experiment.  Soil solubilisation in the undisturbed cores was less than both repacked cores and air-dried soils, demonstrating that soil C solubilisation increases with increasing soil disturbance.  The acid neutralising capacity (ANC) forcing potential of cow urine was 11.8 meq L–¹, which was more than 20 times greater than sodium nitrate fertiliser application (30 kg N ha-¹ year-¹), although the nitrogen loading rates of the urine were higher than the fertiliser .  ANC forcing has been linked to increasing soil pH and dissolved organic C leaching, and may have been a factor in soil C solubilisation under urine patches.  Upon assessing water stable aggregates after urine application, disaggregation of soil was not a major factor in soil C solubilisation.  
The key conclusions were that:
•	there was strong evidence to support the hypothesis that urine deposition led to soil C solubilisation and priming of soil C mineralisation, that could have contributed to the reported declines in soil C in dairy pastures;
•	priming of soil C decomposition was 10 times greater than leaching and may be the predominant mechanism of soil C loss following urine deposition; and
•	urine deposition resulted in greater losses of soil C from pasture soils than pine soils, in contrast to expectations that soil C in pasture soils would have been acclimatised to urine application.
The work in this thesis was laboratory based and requires further testing under field conditions.  Further work is also needed to establish the mechanisms of soil C solubilisation and the role of solubilised soil C in priming of soil C mineralisation.

text: Soil carbon loss under pasture and pine: Responses to urine addition There have been reports of losses of soil carbon (C) in New Zealand pastures under dairy grazing.  Acceleration of mineralisation or leaching of soil C following urine deposition may decrease soil C.  However, little research of the effect of cow urine on soil C has been conducted.  The overall objective of this thesis was to investigate the potential for dairy cow urine to solubilise soil C, which can then be lost through mineralisation or leaching.  Soils from both grazed pasture and Pinus radiata plantations (termed pasture and pine soils) were investigated.

The concentration, composition, and bioavailability of urine-C were investigated.  Cow urine contained 7.5±1.2 g C L–¹, with a C:N ratio of 2:1.  About 45% of the C content of cow urine was attributed to hippuric acid, the other major contributors were urea, an unidentified amide and phenaceturic acid.  On incubation at 25°C, up to 25% of urine-C was degraded in 28 days, demonstrating that cow urine is biodegradable and could potentially act to prime C mineralisation in soils.  

Solubilisation of soil C (0-20 cm soil depth) following urine application was tested by measuring adsorption of urine-C and subsequent desorption of soil C in air-dried pine and pasture soils.  While adsorption was low at 3% of urine-C, the solubilisation of soil C by urine ranged between 11-28% of soil C concentration for 5 different soils, however, solubilisation was likely overestimated due to the use of air-dried soils.  Soil C solubilisation was also measured in field moist soils applied with artificial urine, and was less than that reported from air-dried soils.  

Priming of soil C mineralisation, solubilisation, and extracellular enzyme activity were measured using moist repacked pine and pasture soil cores (0-5 cm soil depth) treated with cow urine or radio-labelled artificial urine.  Positive priming of soil C mineralisation, where more carbon dioxide (CO₂) was produced than C added, was measured following application of cow urine in both pine and pasture soils.  The pasture soils lost 5.1±0.9%, and the pine soils 4.0±0.1%, of soil C concentration as CO₂ during a 84 day incubation.  Positive priming was attributed to increased microbial and urease activity and accelerated soil C mineralisation in urine treated soils.  The remaining extracellular enzyme activities assayed were unlikely to have contributed to soil C priming.  In contrast to the positive priming measured following cow urine application, treatment of soil with artificial urine resulted in less CO₂ produced than C added – or negative priming.  Increased soil pH following urine application may have played an important role in increasing C mineralisation as water soluble C increased with increasing soil pH.  Therefore, cow urine can cause priming of soil C mineralisation and lead to a loss of soil C.  However, artificial urine may not adequately model cow urine with respect to C cycling.

Soil C solubilisation by urine and subsequent leaching from undisturbed pasture soil (0-5 cm soil depth) was assessed by applying δ¹³C enriched urine.  Leaching resulted in a loss of 0.45±0.03% of soil C concentration, which was 10 times greater than the loss of soil C in the water control treatment (0.048±0.001%).  The leaching of soil C was small compared to the 5% loss of soil C by priming in the repacked core experiment.  Soil solubilisation in the undisturbed cores was less than both repacked cores and air-dried soils, demonstrating that soil C solubilisation increases with increasing soil disturbance.  The acid neutralising capacity (ANC) forcing potential of cow urine was 11.8 meq L–¹, which was more than 20 times greater than sodium nitrate fertiliser application (30 kg N ha-¹ year-¹), although the nitrogen loading rates of the urine were higher than the fertiliser .  ANC forcing has been linked to increasing soil pH and dissolved organic C leaching, and may have been a factor in soil C solubilisation under urine patches.  Upon assessing water stable aggregates after urine application, disaggregation of soil was not a major factor in soil C solubilisation.  
The key conclusions were that:
•	there was strong evidence to support the hypothesis that urine deposition led to soil C solubilisation and priming of soil C mineralisation, that could have contributed to the reported declines in soil C in dairy pastures;
•	priming of soil C decomposition was 10 times greater than leaching and may be the predominant mechanism of soil C loss following urine deposition; and
•	urine deposition resulted in greater losses of soil C from pasture soils than pine soils, in contrast to expectations that soil C in pasture soils would have been acclimatised to urine application.
The work in this thesis was laboratory based and requires further testing under field conditions.  Further work is also needed to establish the mechanisms of soil C solubilisation and the role of solubilised soil C in priming of soil C mineralisation.

year: 2012

title: Materials for enhancing denitrification performance in partially saturated vertical flow wetlands for marae

authors: Liu, Lucian XiaoRan

abstract: There are upwards of 773 marae in New Zealand which are responsible for many key events for the indigenous people, Māori, many of which are located rurally and have inadequate on-site wastewater treatment mostly comprising of a septic tank followed by land application. Māori have many strong beliefs about water and subsequently criteria surround the treatment of wastewater due to the effects it can have on people and environment. One proposed solution that meets criteria are treatment wetlands, more specifically partially saturated vertical flow wetlands which require a smaller footprint and produce better effluent than traditional wetland designs. NIWA (National Institute of Water and Atmospheric Research) has experimented with mesocosm scale versions of this design and has encountered issues with denitrification in the saturated zone.

This research is therefore directed at enhancing denitrification in the saturated zone with materials that are able to supplement organic carbon for denitrification. Several woodchip materials (Eastern Cottonwood, Mahogany, Manuka, Eucalyptus, Crack Willow, Princess Tree and Pine) along with two industry by-product materials (Brewers Spent Grain and Slum gum) and Coir (Coconut derivative) were examined for denitrification capabilities and to serve in producing a leachate for dosing the proposed system to supplement organic carbon for denitrification.

The research is split into three phases; the first examines the ability of materials to release organic carbon into water over 60 days, the second examines the same but over three 10 day cycles, and the third quantifies denitrification performance of the materials at lab scale.

Results showed that producing a suitable leachate is not possible without the use of fresh material for each batch. By-product materials had great capacity for releasing organic carbon into water and denitrification (up to 85.5% nitrate removal) but had limited lifespans as media. While woodchip materials did not exhibit as great carbon release, they achieved comparable denitrification (74.2-74.5% nitrate removal) with long lifespans. Therefore, a woodchip and industry by-product mix could be the solution. Alternatively, there are many woodchip species, some which could have better denitrification capacity or suitable industry by-products with longer useful lifespans.

text: Materials for enhancing denitrification performance in partially saturated vertical flow wetlands for marae There are upwards of 773 marae in New Zealand which are responsible for many key events for the indigenous people, Māori, many of which are located rurally and have inadequate on-site wastewater treatment mostly comprising of a septic tank followed by land application. Māori have many strong beliefs about water and subsequently criteria surround the treatment of wastewater due to the effects it can have on people and environment. One proposed solution that meets criteria are treatment wetlands, more specifically partially saturated vertical flow wetlands which require a smaller footprint and produce better effluent than traditional wetland designs. NIWA (National Institute of Water and Atmospheric Research) has experimented with mesocosm scale versions of this design and has encountered issues with denitrification in the saturated zone.

This research is therefore directed at enhancing denitrification in the saturated zone with materials that are able to supplement organic carbon for denitrification. Several woodchip materials (Eastern Cottonwood, Mahogany, Manuka, Eucalyptus, Crack Willow, Princess Tree and Pine) along with two industry by-product materials (Brewers Spent Grain and Slum gum) and Coir (Coconut derivative) were examined for denitrification capabilities and to serve in producing a leachate for dosing the proposed system to supplement organic carbon for denitrification.

The research is split into three phases; the first examines the ability of materials to release organic carbon into water over 60 days, the second examines the same but over three 10 day cycles, and the third quantifies denitrification performance of the materials at lab scale.

Results showed that producing a suitable leachate is not possible without the use of fresh material for each batch. By-product materials had great capacity for releasing organic carbon into water and denitrification (up to 85.5% nitrate removal) but had limited lifespans as media. While woodchip materials did not exhibit as great carbon release, they achieved comparable denitrification (74.2-74.5% nitrate removal) with long lifespans. Therefore, a woodchip and industry by-product mix could be the solution. Alternatively, there are many woodchip species, some which could have better denitrification capacity or suitable industry by-products with longer useful lifespans.

year: 2023