Perbanyakan Mikro Colocasia Esculenta (L.) Schott Var. Antiquorum melalui Penggunaan IAA

Media perbanyakan in vitrosangat diperlukan untuk meningkatkan kemampuan multipikasi tunas maupun kualitas bibit. Media Murashige Shoog (MS)dapatditambahkanzat pengatur tumbuh sebagai pemacu pertumbuhan dalam kultur in vitro.Penelitian ini bertujuan untuk mendapatkan konsentrasi IAA terbaik bagi pertumbuhan talas jepang dalam kulturin vitro. Perlakuan terdiri dari 4 taraf konsentrasi IAA yaitu I0 (0 mg/L), I1 (0,5 mg/L), I2 (1 mg/L), I3 (1,5 mg/L) yang diulang sebanyak 5 kali dalam rancangan acak kelompok. Hasil penelitian ini menunjukan bahwa pemberian IAA berpengaruh nyata terhadap saat muncul tunas, jumlah tunas, tinggi tunas, jumlah daun dan jumlah akar satoimo. Konsentrasi IAA 0,5 mg/L merupakan konsentrasi terbaik untuk pertumbuhan akar dan saat muncul tunas talas satoimo, sedangkan konsentrasi IAA 1 mg/L merupakan konsentrasi terbaik untuk jumlah tunas, tinggi tunas dan jumlah daun satoimo. Kata kunci: kultur in vitro, talas jepang, IAA, perbanyaka

Using N-mixture models to estimate abundance and temporal trends of black rhinoceros (Diceros bicornis L.) populations from aerial counts

Inaccurate estimates of animal populations may lead to flawed management interventions, therefore, it is essential to understand the status and population trend of a species in order to plan its management efficiently. Aerial surveys are considered a useful method for estimating the population size of large conspicuous animals inhabiting large areas, but raw count data from aerial surveys usually underestimate population sizes due to imperfect detection. The use of N-mixture models with aerial count data provides a useful tool to estimate the population sizes while taking detection probability into account. As a study case we used aerial surveys conducted for monitoring black rhinoceros (Diceros bicornis) in Madikwe Game Reserve and Pilanesberg Nature Reserve (South Africa) during 1999–2015, and we analysed data with a dynamic extension of the N-mixture model. We estimated 0.078–0.098 and 0.139–0.142 individuals/km2, respectively, and we found evidence for density dependence in both reserves with a carrying capacity of 0.122 (0.102–0.142) individuals/100 km2. Based on simulations used to assess precision of the estimates, root-mean-square error model (RMSE) estimates was significantly smaller than those for the raw maximum counts. The N-mixture models provide a promising approach to estimate population size, trends and demographic characteristics of large conspicuous mammals such as black rhinoceroses. Such analysis can provide estimates that are more accurate than raw counts. In addition, use of model covariates that affect a species' population parameters can provide useful information for their conservation and management.Jose Jimenez is funded by Plan TIFIES (Spanish Action Plan against illegal trafficking and international poaching of wild species). Ministerio para la Transición Ecológica. Government of Spain.Peer reviewe

The megaproject sponsor as leader

CITATION: Louw, W., et al. 2018. The megaproject sponsor as leader. South African Journal of Industrial Engineering, 29(3):173-187, doi:10.7166/29-3-2058.The original publication is available at http://sajie.journals.ac.zaENGLISH ABSTRACT: The importance of the sponsor role, including its contribution to the success or failure of a project, is widely recognised in the project management literature. References to the sponsor’s leadership, and the substantial component it represents in the profile of the sponsor, are equally prevalent in the literature reviewed. A megaproject is a large-scale, complex venture that typically costs US$1 billion or more, takes many years to develop and build, involves multiple public and private stakeholders, is transformational, and influences millions of people. Executive sponsors are primarily allocated to projects of strategic importance that are complex, carry a considerable degree of risk, and are very visible. A megaproject is thus entitled to a sponsor from the executive (most senior) ranks within an organisation. Rather than joining the debates on complexity and leadership in the project management literature, this paper explains how leadership theories are used to identify instruments that can assist in the assessment of the leadership style and traits/attributes of a sponsor. A framework is then proposed to identify assessment instruments to evaluate the leadership style and leader traits/attributes of a project sponsor.AFRIKAANSE OPSOMMING: Die belangrikheid van die rol van die bestuursborg, insluitend die bydrae wat hy/sy maak tot die sukses of faling van ’n projek word wyd erken in die projekbestuur literatuur. Verwysings na die leierskapsrol van die bestuursborg asook die wesenlike komponent wat dit uitmaak van die profiel van die bestuursborg word bykans net soveel aangetref in die literatuur. ’n Megaprojek word gedefinieer as ’n grootskaalse, komplekse onderneming wat tipies 1 miljard Amerikaanse dollar of meer kos, etlike jare neem om te ontwikkel en te bou, veelvuldige publieke en privaat belanghebbendes betrek, transformasioneel van aard is, en miljoene mense beïnvloed. Uitvoerende bestuursborge word hoofsaaklik aangewys vir projekte van strategiese aard wat kompleks is, ’n beduidende hoeveelheid risiko dra, en uitsonderlik sigbaar is. Dit is dus duidelik dat ’n megaprojek geregtig is op ’n bestuursborg vanuit die uitvoerende en mees senior bestuursvlakke van ’n organisasie. Eerder as om aan te sluit by die debatte oor kompleksiteit en leierskap in die projekbestuur literatuur, dui hierdie artikel aan tot welke mate leierskapsteorieë benut kan word om instrumente te identifiseer wat kan meehelp in die evaluering van leierskapstyle asook die leierskap eienskappe/ attribute van ’n bestuursborg. Ter afsluiting word ’n raamwerk voorgestel om assesseringsinstrumente te identifiseer vir die evaluering van leierskapstyle en leier eienskappe/ attribute.http://sajie.journals.ac.za/pub/article/view/2058Publisher's versio

Helicobacter pylori prevalence in non-ulcer dyspepsia ethnic and socio-economic differences

Helicobacter pylori is an important cause of gastritis and a number of therapeutic. trials suggest that it may be important in the genesis of duodenal ulcer recurrence. The reported prevalence of gastric colonisation by the organism varies considerably. The aiIn of this cross-sectional survey was to determine its prevalence in non-ulcer dyspeptics and to determine whether this is influenced by age, race, sex, socio-economic status, educational level and the nwnber of persons sharing accommodation. One hundred and sixty-nine patients underwent endoscopy; biopsy speciInens were taken from the antrwn and H. pylori status was determined histologically. Gastric colonisation was found in 106 patients (63%). The prevalence showed a marked ethnic difference: 40% in whites and 71% in coloureds (P < 0,001). The ethnic groups were characterised by significant differences in socio-economic status (P < 10-6), educational level (P < 10-6), number of persons sharing accommodation (P < 10-6 ) and age (P < 0,001). These same differences were found when comparing the H. pylori-positive and negative groups, but were less marked and could be attributed to the marked differences between ethnic groups. We conclude that H. pylori prevalence differs between the ethnic groups studied. This may be because of varying degrees of exposure risk

The A-ring reduction of 11-ketotestosterone is efficiently catalysed by AKR1D1 and SRD5A2 but not SRD5A1

Testosterone and its 5α-reduced form, 5α-dihydrotestosterone, were previously thought to represent the only active androgens in humans. However, recent studies have shown that the potent androgen, 11-ketotestosterone, derived from the adrenal androgen precursor, 11β-hydroxyandrostenedione, may in fact serve as the primary androgen in healthy women. Yet, despite recent renewed interest in these steroids, their downstream metabolism has remained undetermined. We therefore set out to investigate the metabolism of 11-ketotestosterone by characterising the 5α- or 5β-reduction commitment step. We show that inactivation of 11-ketotestosterone is predominantly driven by AKR1D1, which efficiently catalyses the 5β-reduction of 11-ketotestosterone, committing it to a metabolic pathway that terminates in 11-ketoetiocholanolone. We demonstrate that 5α-reduction of 11-ketotestosterone is catalysed by SRD5A2, but not SRD5A1, and terminates in 11-ketoandrosterone, but is only responsible for a minority of 11-ketotestosterone inactivation. However, as 11-ketoetiocholanolone is also generated by the metabolism of the glucocorticoid cortisone, 11-ketoandrosterone should be considered a more specific urinary marker of 11-ketotestosterone production

A collaborative and evolving response to the needs of frontline workers, patients and families during the COVID-19 pandemic at Tygerberg Hospital, Western Cape Province, South Africa

The global devastation caused by the COVID-19 pandemic and its mental health impact is undeniable. The physical and psychological consequences are wide-ranging – affecting patients fighting the disease, frontline workers in the trenches with them, healthcare staff deployed in high-care settings, and families disconnected from their loved ones in their darkest hours. Within 6 weeks of the COVID-19 outbreak in South Africa, the Department of Psychiatry at Stellenbosch University established the TBH/SU COVID Resiliency Clinic to provide psychological support to frontline workers at Tygerberg Hospital. Identified barriers in healthcare workers accessing mental healthcare resulted in moving towards an on-site visibility to try to remove some of these barriers. This greater on-site presence enabled networking and building of relationships with frontline staff that over time highlighted other frontline needs, such as providing psychosocial and spiritual support to patients and their families. We share challenges, lessons learned and recommendations from two initiatives: the TBH/SU COVID-19 Resiliency Clinic, and an embedded COVID Care Team (CCT). We describe the establishment, roll-out and progress of the Clinic and the subsequent CCT