The economics of potato crop rotations in southern Manitoba

Non-Peer ReviewedRapid expansion of the potato industry in Manitoba has led to increased potato production in Manitoba. While the introduction of potatoes into current cropping systems may provide an opportunity for producers to increase the profitability of their farming operation, development of economically and environmentally sustainable production systems is key to the long-term success of the industry. Currently, little information is available about the economic and environmental impacts of such crop rotations with respect to potato production in Canada. Recognizing the importance of sustainable production systems, in 1998, a potato crop rotation study was established at Manitoba Crop Diversification Center (MCDC) at Carberry to develop recommendations for irrigated potato management in southern Manitoba. Six crop rotations ranging from two to four years in duration, and containing potatoes in combination with oilseed, cereal and/or legume crops, were included in this study. Each phase of each rotation was present in each year making a total of 18 treatments. This paper discusses the economic return of these six different crop rotations. The data with respect to all the production practices, including storage, transport and marketing for the period of 1998 to 2001 were collected and analyzed using a computer model developed for this purpose. Econometrics View software was used to develop this model, and the model takes into account the whole system for each rotation when analyzing the data. The preliminary results suggest that, for the period of 1999 through 2000, both potato-canola and potato-oat-wheat rotations appeared to be promising rotations. However, the poor potato yield of the potato-oatwheat rotation in 2001 resulted in low average net income for that rotation. The higher net benefit of the potato-canola rotation during the time period analyzed was primarily the result of a higher proportion of the tuber yield being of marketable size, not for higher gross tuber or canola yields. It is, however, difficult to make firm conclusions at this point of time as to which rotation will be most profitable in the long term. This is mainly because of the rotation treatments have only been in place since 1998 and, as such, observed differences among rotations may be a function not only of the rotation but also of environmental conditions and management within a given year

Factors associated with repeat genital symptoms among sexually transmitted infection service attendees in South Africa, 2015 - 2016

Background. South African guidelines recommend a syndromic approach for the management of sexually transmitted infections (STIs), based on the presence of genital symptoms. However, the guidelines do not prescribe specific indications for microbiology testing for patients presenting with or without repeat genital symptoms.Objectives. To describe the prevalence of and factors associated with repeat genital symptoms among STI service attendees at primary care facilities.Methods. This was a cross-sectional study at 7 STI primary care facilities participating in the aetiological surveillance of STIs between January 2015 and December 2016. Demographic and clinical information and appropriate genital specimens were collected from participants presenting with vaginal discharge syndrome (VDS), male urethral syndrome (MUS) and/or genital ulcer syndrome (GUS). Repeat genital symptoms were defined as self-reported history of the same STI-related genital symptoms in the preceding 12 months. Multivariable logistic regression identified factors associated with repeat genital symptoms.Results. Of 1 822 eligible participants, 480 (30%) had repeat genital symptoms (25% and 75% in the preceding 3 months and 12 months, respectively). Of those with repeat genital symptoms, the median age was 28 (interquartile range (IQR) 24 - 32) years, and 54% were females. The most common aetiological agents among participants with VDS, MUS and GUS were bacterial vaginosis (n=132; 55%), Neisseria gonorrhoeae (n=172; 81%) and ulcers (n=67; 63%), respectively. One hundred and seven (20%) participants had no detectable common STI aetiology. In the multivariable analysis, repeat genital symptoms were associated with HIV co-infection (adjusted odds ratio (aOR) 1.43; 95% confidence interval (CI) 1.14 - 1.78), VDS diagnosis (aOR 1.39; 95% CI 1.10 - 1.76), self-reported condom use (aOR 1.56; 95% CI 1.20 - 2.03) and age 25 - 34 years (aOR 1.33; 95% CI 1.03 - 1.71).Conclusions. Our study found a high prevalence of repeat genital symptoms ‒ a significant proportion without STI aetiology. Identified factors of repeat genital symptoms highlight the need for improved integration of HIV and STI prevention and management. Further research is needed to determine the aetiology of repeat genital symptoms and the contribution of non-STI causes

A case series of spotted fever rickettsiosis with neurological manifestations in Sri Lanka

SummaryBackgroundSpotted fever group (SFG) rickettsial infections are increasingly detected in Sri Lanka. We describe 17 patients with SFG who developed neurological manifestations.MethodsThe cases were studied prospectively from 2008 at the Teaching Hospital, Peradeniya. An immunofluorescent antibody assay (IFA) was used to confirm the diagnosis.ResultsAll had an IFA IgG titer ranging from 1/64 to 1/4096 and a positive IFA IgM titer against Rickettsia conorii antigen; in 10 (59%) cases the IgG titers were ≥1/256 (definitive cases). The median age of the patients was 62 years (range 26–82 years); 10 were male and seven female. The median duration of fever was 12 days (range 4–35 days). Neurological manifestations on admission were drowsiness or confusion in 14 (82%) and a semi-comatose state in three (18%). Rigidity of the limbs occurred in 14 (82%), bradykinesia and resting tremors in 12 (71%), which persisted after defervescence, neck stiffness in seven (42%), weakness of the limbs in five (29%), deafness in two (12%), and stupor in three (18%). Electroencephalograms in three (18%) showed generalized slow waves. Cerebrospinal fluid examination showed a cellular reaction, predominantly lymphocytes, in three cases. Two patients died (fatality rate 12%).ConclusionWe have documented for the first time the neurological features of SFG rickettsioses in the Central Province, Sri Lanka. These were predominantly extrapyramidal features in patients of older age

INVESTIGATION OF SULFUR COMPOUNDS IN SELECTED STAGNANT WATER BODIES

Sulfur compounds, primarily in the form of sulfides (S2.), sulfites (50)'") andsulfates (50t) have been neglected but has a strong effect upon water quality.The dark colour sediments and strong unpleasant ordours often indicate the 52.contamination in aquatic bodies. To the best of our knowledge, no attempt hasbeen made to investigate these compounds and to asses their contribution to thedegradation of water quality. Both the bacteria and dissolved oxygen (DO) areplaying leading roles in determining the fate of 5 containing compounds inaquatic systems.In this investigation it was intended to study the possible relationships betweensulfur species and DO. Four urban stagnant water bodies effected by impropersewage disposal, industrial waste, wet and dry deposition of atmospheric 50/'were investigated along with a prawn farm and two coconut husk soaking pitsinherited with S compounds. These water bodies indicated the emission ofvolatile 5 compounds. These water bodies indicated the emission of volatile 5compounds From their characteristic rotten egg smell.Under this study 52., SO)·2 and 50t levels were monitored along with DO, pHand temperature to investigate the possible correlation method introduced byPawlak and Pawlak (1999) was employed in determination of 52. levels while allother parameters were measured by employing standard methods.Based on the results obtained, only S2. shows a significant correlation with DOunder ambient conditions. Finally, measured dissolved 52. levels were utilized todetermine the possible H25 emission levels. Calculations have shown that each ofthe water body is emitting gaseous H25 and in most cases, emission levels aregreater than the ordour thresholds accounting for the unpleasant smell near thesestagnant water bodies.*Correspondence author

CONSTRUCTION OF A LOW COST AIR SAMPLER AND IT'S APPLICATION IN SAMPLING VOLATILE CARBONYL COMPOUNDS

lntcrcxt is expanding in measuring. concentrations of volatile organic compounds inbuildings since it is rccogniscd that many peoples' exposure to these compounds occur inthe indoor environment. However. such data are not available in Sri Lanka primarily dueto lack 01"proper equipment for quantitation and their high maintenance cost. This paperdcxcribcx the construction of a low cost air sampler (Rs. 40()/=) using commonly availablematerials.The air sampler contains a muffler fan to pull .unhient air though a filrcrts) and/or a bed ofsorhcnt material. which are housed in a variable length pye tube. Battery poweredmuffler fan and lightweight are two of the convenient features of this air sampler thatminimisc operational and transportation difficulties to the user.Vularilc carbonyl compounds such as formaldehyde acetaldehyde and acetone arecommonly found in indoors ambient air due to the combustion sources and emissions fromsvnthcric household products. Since formaldehyde is a known carcinogen andacetaldehyde is a suspected carcinogen compound. they were selected as the modelcompounds for the evaluation of constructed sampler. A filter paper spiked with 2. 4-dinitrophcnylhydruzcnc is used to collect the airborne carbonyl compounds at a flow rate ofI.X Cill'/SCC. Filters were sonicated in methanol and extracts were separated using a C,xcolumn for qu.uuitation at lSO mm wavelength. Quanutaiion limits estimates thats.unpling of I () dm ' ambient air enables minimum quantitauon of O.S formaldehyde. 1.0acetaldehyde and 1.2 acetone accurately. The paper also reports quantified levels ofairborne carbonyls from different indoor environments.

Contribution of dissolved sulfates and sulfites in hydrogen sulfide emission from stagnant water bodies in Sri Lanka

Abstract Accumulation of sulfur-containing compounds and their bacterial mediated reductions have led to the emission of pungent odors from stagnant water bodies. This study is focused on the contribution of inorganic sulfur compounds in the emission of hydrogen sulfide. The measured dissolved oxygen levels have demonstrated good negative correlations with the dissolved sulfide levels implying the oxygen deficiency is the key for the reduction of sulfate ion and sulfite ion to sulfide ion. Particularly, the dissolved molar fractions of sulfide from the total dissolved sulfur compounds (sulfates, sulfites and sulfides) have a very good correlation with the dissolved oxygen for the stagnant water bodies except the artificially aerated prawn farms. For the stagnant water bodies with significant correlations, linear regressions are reported for them to be utilized in estimating one component of the regression from the measurement of the other. The measured data were further utilized to estimate the levels of hydrogen sulfide gas. The pH of the water bodies has confined much of the dissolved sulfides in the form of bisulfide ion and they can be easily escaped to the atmosphere upon acidification due to industrial discharges and/or acidic precipitations. The estimated levels of hydrogen sulfide just above the water surface were plotted for the most polluted stagnant water body in Sri Lanka for the pH range of 5-10 and temperature range of 25-35°C

The demographic and clinical profiles of women presenting with vaginal discharge syndrome at primary care facilities in South Africa: Associations with age and implications for management

Background. Current South African guidelines for the management of vaginal discharge syndrome (VDS) do not recommend treatment for sexually transmitted infection (STI) pathogens for women aged ≥35 years whose partners do not have male urethritis syndrome. The guideline assumes that older women are unlikely to have an STI and that their partners do not have asymptomatic infections.Objectives. To describe the demographic, behavioural and clinical characteristics of women with VDS, comparing older women (≥35 years) with younger women, and to determine the performance of age alone as a criterion for predicting the presence of STI.Methods. This was a cross-sectional study at seven primary healthcare centres taking part in the aetiological surveillance of STIs between January 2015 and December 2016. Eligible women presenting with VDS were enrolled and completed a nurse-administered questionnaire. Genital swabs and blood specimens were collected for laboratory testing. Data were entered into surveillance-specific databases and exported into Stata 14 for analysis. Descriptive statistics were used to compare demographic and clinical profiles of older with younger women. A receiver operator curve (ROC) was used to determine the age cut-off that would best differentiate between women who had infection with STI pathogens and those without.Results. Of 757 women enrolled, 157 (20.7%) were aged ≥35 years. HIV positivity was 46.6%, and higher in older than younger women (54.9% v. 44.5%; p=0.02). Of those enrolled, 283 (37.4%) had bacterial vaginosis (BV) and/or Candida infection only, 232 (30.7%) had BV or Candida with STI pathogens detected, 98 (13%) were infected with STI pathogens only, and 144 (19.0%) did not have any detectable STI or non-STI causes. Although older women were less likely than younger women to have Neisseria gonorrhoeae, Chlamydia trachomatis or Mycoplasma genitalium infection (23.6% v. 38.2%; p<0.01), the burden in older women was not negligible. The area under the ROC for age was 57.5% (95% confidence interval 53.2 - 61.8%), which implies suboptimal performance.Conclusions. Although older women with VDS were less likely than younger women to have STIs, a significant proportion of them did have an infection with STI pathogens. Age alone was not a good criterion for discriminating between women with and without infection with STI pathogens. Other ways of improving the VDS algorithm performance are needed, as is better integration of HIV and STI prevention and treatment.Â

Factors associated with repeat genital symptoms among sexually transmitted infection service attendees in South Africa, 2015-2016

BACKGROUND. South African guidelines recommend a syndromic approach for the management of sexually transmitted infections (STIs), based on the presence of genital symptoms. However, the guidelines do not prescribe specific indications for microbiology testing for patients presenting with or without repeat genital symptoms. OBJECTIVES. To describe the prevalence of and factors associated with repeat genital symptoms among STI service attendees at primary care facilities. METHODS. This was a cross-sectional study at 7 STI primary care facilities participating in the aetiological surveillance of STIs between January 2015 and December 2016. Demographic and clinical information and appropriate genital specimens were collected from participants presenting with vaginal discharge syndrome (VDS), male urethral syndrome (MUS) and/or genital ulcer syndrome (GUS). Repeat genital symptoms were defined as self-reported history of the same STI-related genital symptoms in the preceding 12 months. Multivariable logistic regression identified factors associated with repeat genital symptoms. RESULTS. Of 1 822 eligible participants, 480 (30%) had repeat genital symptoms (25% and 75% in the preceding 3 months and 12 months, respectively). Of those with repeat genital symptoms, the median age was 28 (interquartile range (IQR) 24 - 32) years, and 54% were females. The most common aetiological agents among participants with VDS, MUS and GUS were bacterial vaginosis (n=132; 55%), Neisseria gonorrhoeae (n=172; 81%) and ulcers (n=67; 63%), respectively. One hundred and seven (20%) participants had no detectable common STI aetiology. In the multivariable analysis, repeat genital symptoms were associated with HIV co-infection (adjusted odds ratio (aOR) 1.43; 95% confidence interval (CI) 1.14 - 1.78), VDS diagnosis (aOR 1.39; 95% CI 1.10 - 1.76), self-reported condom use (aOR 1.56; 95% CI 1.20 - 2.03) and age 25 - 34 years (aOR 1.33; 95% CI 1.03 - 1.71). CONCLUSIONS. Our study found a high prevalence of repeat genital symptoms ‒ a significant proportion without STI aetiology. Identified factors of repeat genital symptoms highlight the need for improved integration of HIV and STI prevention and management. Further research is needed to determine the aetiology of repeat genital symptoms and the contribution of non-STI causes.The SA National Department of Health through a core surveillance funding grant to the National Institute for Communicable Diseases (NICD).http://www.samj.org.zaam2021School of Health Systems and Public Health (SHSPH