A productivity model for first thinning of Pinus patula using a tractor and double-drum winch in South Africa

The productivity of skidding tractors in intermediate harvesting operations has not been determined in Mpumalanga, South Africa. The objective of this study was to develop a productivity model using a farm tractor in first thinning operations in Pinus patula compartments. A work study design was used to assess the performance of a skidding agricultural tractor. From 350 samples, important data variables collected were elemental times for each work cycle, extraction distance, slope and load volume. Stepwise and subsets regression analyses were conducted prior to multiple linear regression analysis. Analysis of variance was used to compare mean productivity estimates of the different models developed. Results showed that the best model was estimated by an interaction of distance × slope (ds), distance × load volume (dv) and slope × load volume (sv) as follows: ln(ŷ2) = 1.33–0.00154ds + 0.00174dv + 0.161sv. The mean estimate for this model was 5.036 m3 m h−1. The developed models predicted similar results to estimation results of the observed model, although there were statistically significant (P < 0.001) differences among mean estimates (3.6–5.5 m3 m h−1). All of the three models yielded R2adj. = 38%; SE = 0.458% at P < 0.001. It can be speculated that the remaining variation not explained by the models may be associated with long extraction distances, delays and the effect of slope as a main variable in the model. While the developed models mirrored reasonably well with the observed estimates of skidding productivity, these models should not be stretched to conditions dissimilar to those of their generation. Future research focus should be made on (1) effects of weather conditions and vehicular characteristics on skidding productivity and (2) the effect of winching lines on skidding productivity.SAFCOLhttp://www.tandfonline.com/loi/tsfs202019-01-01hj2018Plant Production and Soil Scienc

Performance of a Novel Human Immunodeficiency Virus (HIV) Type 1 Total Nucleic Acid-Based Real-Time PCR Assay Using Whole Blood and Dried Blood Spots for Diagnosis of HIV in Infants▿

The new Cobas AmpliPrep/Cobas TaqMan HIV-1 Qual test offers advanced automation for the detection of human immunodeficiency virus type 1 (HIV-1) RNA and DNA in dried blood spots (DBS) and whole blood. An analytical evaluation using an HIV-1 secondary standard yielded limits of detection of 514, 710, and 1,090 HIV RNA copies/ml for EDTA plasma, whole blood, and DBS, respectively. The precision and reproducibility of HIV-1 detection was equivalent for DBS and whole blood. Inclusivity was demonstrated for a reference panel of HIV-1 subtypes A to N. A clinical evaluation of the Cobas AmpliPrep/Cobas TaqMan HIV-1 Qual test was performed at a center for routine diagnostics in Johannesburg, South Africa, using 1,013 clinical specimens from HIV-1 exposed children. The Amplicor HIV-1 DNA test v1.5 with the MagNApure DNA isolation procedure was used as the reference method. A total of 995 valid results for whole blood with both methods yielded 691 and 303 concordant negative and positive results for the Cobas AmpliPrep/Cobas TaqMan HIV-1 Qual test, respectively. For the 800 valid DBS specimen results, 495 and 300 concordant negative and positive results were obtained, respectively. The resulting clinical specificities and sensitivities of the new test were 100% and 99.7% for whole blood and DBS, respectively. The new test was characterized by its robustness, enhanced automation, and improved sample throughput. The Cobas AmpliPrep/Cobas TaqMan HIV-1 Qual test will support early, reliable diagnosis of HIV in children in routine laboratory settings

Multidisciplinary Gynecologic Oncology Clinic in Botswana: A Model for Multidisciplinary Oncology Care in Low- and Middle-Income Settings

Purpose Cervical cancer is a major cause of mortality in low- and middle-income countries (LMICs) and the most common cancer diagnosed in women in Botswana. Most women present with locally advanced disease, requiring chemotherapy and radiation. Care co-ordination requires input from a multidisciplinary team (MDT) to deliver appropriate, timely treatment. However, there are limited published examples of MDT implementation in LMICs. Methods: In May 2015, a weekly MDT clinic for gynecologic cancer care was initiated at Botswana’s national referral facility. The MDT clinic served as a forum for discussion and coordination of patients with gynecologic cancer and consisted of a gynecologist, pathologist, medical oncologist, radiation oncologist, palliative care specialist, and nurse coordinator. Results: Between May 2015 and December 2015, 135 patients were seen in the MDT clinic. The mean age of the patients was 49 years. Most (60%) of the patients were HIV positive. The most common diagnosis was cervical cancer (60%), followed by high-grade cervical intraepithelial neoplastic lesions (12%) and vulvar cancer (11%). Only data up to September 2015 were assessed for treatment delays. It was found that only 38% of patients needed more than one visit for care coordination before treatment initiation. Among patients with cervical cancer, the median delay from date of biopsy to start of radiation treatment was 39 days (interquartile range, 34 to 57 days) for patients treated after MDT initiation, compared with 108 days (interquartile range, 71 to 147 days) for patients treated before MDT initiation (P < .001). Conclusion: Implementation of MDT clinics in LMICs is feasible and can help reduce delays in treatment initiation, as demonstrated by a gynecologic MDT clinic in Botswana. Streamlining care through MDT clinics can enhance care coordination and improve clinical outcomes. This model can apply to cancer care in other LMICs

Vulvar cancer in Botswana in women with and without HIV infection: patterns of treatment and survival outcomes

ObjectivesVulvar cancer is a rare gynecological malignancy. However, the incidence of human papillomavirus (HPV)-associated vulvar disease is increasing, particularly in low- and middle-income countries. HIV infection is associated with an increased risk of HPV-associated vulvar cancer. We evaluated treatment patterns and survival outcomes in a cohort of vulvar cancer patients in Botswana. The primary objective of this study was to determine overall survival and the impact of treatment modality, stage, and HIV status on overall survival.MethodsWomen with vulvar cancer who presented to oncology care in Botswana from January 2015 through August 2019 were prospectively enrolled in this observational cohort study. Demographics, clinical characteristics, treatment, and survival data were collected. Factors associated with survival including age, HIV status, stage, and treatment were evaluated.ResultsOur cohort included 120 women with vulvar cancer. Median age was 42 (IQR 38-47) years. The majority of patients were living with HIV (89%, n=107) that was well-controlled on antiretroviral treatment. Among women with HIV, 54.2% (n=58) were early stage (FIGO stage I/II). In those without HIV, 46.2% (n=6) were early stage (stage I/II). Of the 95 (79%) patients who received treatment, 20.8% (n=25) received surgery, 67.5% (n=81) received radiation therapy, and 24.2% (n=29) received chemotherapy, either alone or in combination. Median follow-up time of all patients was 24.7 (IQR 14.2-39.1) months and 2- year overall survival for all patients was 74%. Multivariate analysis demonstrated improved survival for those who received surgery (HR 0.26; 95% CI 0.08 to 0.86) and poor survival was associated with advanced stage (HR 2.56; 95% CI 1.30 to 5.02). Survival was not associated with HIV status.ConclusionsThe majority of women with vulvar cancer in Botswana are young and living with HIV infection. Just under half of patients present with advanced stage, which was associated with worse survival. Improved survival was seen for those who received surgery

Chemoradiation versus radiation alone in stage IIIB cervical cancer patients with or without human immunodeficiency virus

ObjectiveCervical cancer remains the most common cancer among women in sub-Saharan Africa and is also a leading cause of cancer related deaths among these women. The benefit of chemoradiation in comparison with radiation alone for patients with stage IIIB disease has not been evaluated prospectively in women living with human immunodeficiency virus (HIV). We assessed the survival of chemoradiation versus radiation alone among stage IIIB cervical cancer patients based on HIV status.MethodsBetween February 2013 and June 2018, patients with International Federation of Gynecology and Obstetrics (FIGO) 2009 stage IIIB cervical cancer with or without HIV and treated with chemoradiation or radiation alone, were prospectively enrolled in an observational cohort study. Overall survival was evaluated using the Kaplan-Meier method. Cox proportional hazards modeling was used to analyze associations with survival.ResultsAmong 187 patients, 63% (n=118) of women had co-infection with HIV, and 48% (n=69) received chemoradiation. Regardless of HIV status, patients who received chemoradiation had improved 2 year overall survival compared with those receiving radiation alone (59% vs 41%, p&lt;0.01), even among women living with HIV (60% vs 38%, p=0.02). On multivariable Cox regression analysis, including all patients regardless of HIV status, 2 year overall survival was associated with receipt of chemoradiation (hazard ratio (HR) 0.63, p=0.04) and total radiation dose ≥80 Gy (HR 0.57, p=0.02). Among patients who received an adequate radiation dose of ≥80 Gy, adjusted overall survival rates were similar between chemoradiation versus radiation alone groups (HR 1.07; p=0.90). However, patients who received an inadequate radiation dose of &lt;80 Gy, adjusted survival was significantly higher in chemoradiation versus radiation alone group (HR 0.45, p=0.01).ConclusionsAddition of chemotherapy to standard radiation improved overall survival, regardless of HIV status, and is even more essential in women who cannot receive full doses of radiation