Rainy season characteristics of the Free State Province of South Africa with reference to rain-fed maize production

The study assesses onset of rains, cessation of rains, duration of rainy season and seasonal rainfall at different probability levels. Daily rainfall data for 309 stations located in the Free State Province of South Africa were analysed from 1950 to 2008. The cumulative rainfall over 3 consecutive dekads (10-day periods) and cumulative rainfall over 1 dekad were used to determine onset of rains and cessation of rains respectively. Seasonal rainfall was determined as the accumulated rainfall from November to March. Rainbow statistical software was utilised to test for normality and determine probabilities at 20%, 50% and 80% risk levels. The other rainy season characteristics investigated were the probability of onset failure and probability of rainy season duration of less than 50, 100, 120 and 140 days. These rainy season indices were investigated in relation to maize production in the Free State. Rainfall behaviour during the growing period is one of the main limiting factors to rain-fed maize production, consequently influencing household food security. The results show that for onset of rains there is a large spatial variance over the Free State while cessation of rains shows small variance. There is also an east to west progression of onsets while the duration of the rainy season and seasonal rainfall also increased from west to east. Areas of low risk associated with rainy season characteristics are evident over the Thabo Mofutsanyane, eastern Motheo, eastern and northeastern Lejweleputswa and the Fezile Dabi districts, making these areas highly suitable for maize production. By contrast, high-risk areas are in the western and southern parts of the province and thus dryland maize production has low production potential in these areas

Transvenous right ventricular pacing in a patient with tricuspid mechanical prosthesis

We report a patient in whom permanent endocardial pacing was accomplished by passage of the electrode through a mechanical tricuspid valve. Echocardiography study showed a minimal tricuspid regurgitation

On the non-existence of an R-labeling

We present a family of Eulerian posets which does not have any R-labeling. The result uses a structure theorem for R-labelings of the butterfly poset.Comment: 6 pages, 1 figure. To appear in the journal Orde

Eurasian Arctic greening reveals teleconnections and the potential for novel ecosystems

Arctic warming has been linked to observed increases in tundra shrub cover and growth in recent decades on the basis of significant relationships between deciduous shrub growth/biomass and temperature. These vegetation trends have been linked to Arctic sea ice decline and thus to the sea ice/albedo feedback known as Arctic amplification. However, the interactions between climate, sea ice and tundra vegetation remain poorly understood. Here we reveal a 50- year growth response over a >100,000 km2 area to a rise in summer temperature for alder (Alnus) and willow (Salix), the most abundant shrub genera respectively at and north of the continental treeline. We demonstrate that whereas plant productivity is related to sea ice in late spring, the growing season peak responds to persistent synoptic-scale air masses over West Siberia associated with Fennoscandian weather systems through the Rossby wave train. Substrate is important for biomass accumulation, yet a strong correlation between growth and temperature encompasses all observed soil types. Vegetation is especially responsive to temperature in early summer. These results have significant implications for modelling present and future Low Arctic vegetation responses to climate change, and emphasize the potential for structurally novel ecosystems to emerge fromwithin the tundra zone.Vertaisarviointia edeltävä käsikirjoitu

Asexual expansion of Toxoplasma gondii merozoites is distinct from tachyzoites and entails expression of non-overlapping gene families to attach, invade, and replicate within feline enterocytes

© 2015 Hehl et al.; licensee BioMed Central. Background: The apicomplexan parasite Toxoplasma gondii is cosmopolitan in nature, largely as a result of its highly flexible life cycle. Felids are its only definitive hosts and a wide range of mammals and birds serve as intermediate hosts. The latent bradyzoite stage is orally infectious in all warm-blooded vertebrates and establishes chronic, transmissible infections. When bradyzoites are ingested by felids, they transform into merozoites in enterocytes and expand asexually as part of their coccidian life cycle. In all other intermediate hosts, however, bradyzoites differentiate exclusively to tachyzoites, and disseminate extraintestinally to many cell types. Both merozoites and tachyzoites undergo rapid asexual population expansion, yet possess different effector fates with respect to the cells and tissues they develop in and the subsequent stages they differentiate into. Results: To determine whether merozoites utilize distinct suites of genes to attach, invade, and replicate within feline enterocytes, we performed comparative transcriptional profiling on purified tachyzoites and merozoites. We used high-throughput RNA-Seq to compare the merozoite and tachyzoite transcriptomes. 8323 genes were annotated with sequence reads across the two asexually replicating stages of the parasite life cycle. Metabolism was similar between the two replicating stages. However, significant stage-specific expression differences were measured, with 312 transcripts exclusive to merozoites versus 453 exclusive to tachyzoites. Genes coding for 177 predicted secreted proteins and 64 membrane- associated proteins were annotated as merozoite-specific. The vast majority of known dense-granule (GRA), microneme (MIC), and rhoptry (ROP) genes were not expressed in merozoites. In contrast, a large set of surface proteins (SRS) was expressed exclusively in merozoites. Conclusions: The distinct expression profiles of merozoites and tachyzoites reveal significant additional complexity within the T. gondii life cycle, demonstrating that merozoites are distinct asexual dividing stages which are uniquely adapted to their niche and biological purpose

Lipid Mediator Metabolomics Via LC-MS/MS Profiling and Analysis.

protocolSolid-phase extraction coupled with liquid chromatography tandem mass spectrometry provides a robust and sensitive approach for the identification and quantitation of specialized pro-resolving mediators (lipoxins, resolvins, protectins, and maresins), their pathway markers and the classic eicosanoids. Here, we provide a detailed description of the methodologies employed for the extraction of these mediators from biological systems, setup of the instrumentation, sample processing, and then the procedures followed for their identification and quantitation

Lymph node hemophagocytosis in rickettsial diseases: a pathogenetic role for CD8 T lymphocytes in human monocytic ehrlichiosis (HME)?

BACKGROUND: Human monocytic ehrlichiosis (HME) and Rocky Mountain spotted fever (RMSF) are caused by Ehrlichia chaffeensis and Rickettsia rickettsii, respectively. The pathogenesis of RMSF relates to rickettsia-mediated vascular injury, but it is unclear in HME. METHODS: To study histopathologic responses in the lymphatic system for correlates of immune injury, lymph nodes from patients with HME (n = 6) and RMSF (n = 5) were examined. H&E-stained lymph node tissues were examined for five histopathologic features, including hemophagocytosis, cellularity, necrosis, and vascular congestion and edema. The relative proportions of CD68 macrophages, CD8 and CD4 T lymphocytes, and CD20 B lymphocytes were evaluated by immunohistochemical staining. RESULTS: Hemophagocytosis was similar in HME and RMSF, and was greater than in control cases (p = .015). Cellularity in HME was not different from controls, whereas RMSF lymph nodes were markedly less cellular (p < 0.002). E. chaffeensis-infected mononuclear phagocytes were infrequent compared to R. rickettsii-infected endothelial cells. More CD8 cells in lymph nodes were observed with HME (p < .001), but no quantitative differences in CD4 lymphocytes, macrophages, or B lymphocytes were identified. CONCLUSION: Hemophagocytosis, CD8 T cell expansion, and the paucity of infected cells in HME, suggest that E. chaffeensis infection leads to macrophage activation and immune-mediated injury

Pleosporales

One hundred and five generic types of Pleosporales are described and illustrated. A brief introduction and detailed history with short notes on morphology, molecular phylogeny as well as a general conclusion of each genus are provided. For those genera where the type or a representative specimen is unavailable, a brief note is given. Altogether 174 genera of Pleosporales are treated. Phaeotrichaceae as well as Kriegeriella, Zeuctomorpha and Muroia are excluded from Pleosporales. Based on the multigene phylogenetic analysis, the suborder Massarineae is emended to accommodate five families, viz. Lentitheciaceae, Massarinaceae, Montagnulaceae, Morosphaeriaceae and Trematosphaeriaceae