89 research outputs found
The influence of Amylostereum areolatum diversity and competitive interactions on the fitness of the Sirex parasitic nematode Deladenus siricidicola
The Sirex noctilio (woodwasp)–Amylostereum areolatum (fungus) complex has caused substantial losses to
pine industries in its introduced range. The nematode Deladenus siricidicola that parasitizes S. noctilio and
feeds on A. areolatum is widely used as a biological control agent for S. noctilio, but not with consistent
success. This variable success could be due to factors that influence the feeding and reproductive ability
of the nematode on A. areolatum.We test two main hypotheses that emerge from this prediction. First, we
compared the survival of D. siricidicola on the South African field strain and the Australian laboratory
strain of A. areolatum, to examine a possible incompatibility between nematode and fungal strain. Second,
we examined the competitive interactions of these two A. areolatum strains with two common sapstain
fungi, Diplodia pinea and Ophiostoma ips, that occur in S. noctilio infested trees in South Africa. The effect of
water potential on the outcome of these fungal interactions was also considered. The data showed that
D. siricidicola survives at comparable levels on the two A. areolatum strains. Water potential of the media
significantly influenced growth of the fungi and their ability to capture host resource in competitive
interactions. D. pinea competed increasingly better against A. areolatum with decreasing water potential.
The results suggest that competitive interactions between A. areolatum and sapstain fungi could negatively
influence the success of D. siricidicola, especially under conditions of lowered water potential.The USDA Forest Service, Southern Research Station, Forestry South
Africa (FSA), the Department of Water Affairs and Forestry, the
University of Pretoria and the THRIP initiative of the Department
of Trade and Industry (DTI)htp://www.elsevier.com/locate/ybconab201
УПРАВЛІННЯ ФІНАНСОВИМИ РЕЗЕРВАМИ ПРИ ОПТИМІЗАЦІЇ ФІНАНСОВИХ ПОТОКІВ ПІДПРИЄМСТВА
Уточнена сутність фінансового резерву промислового підприємства. Встановлені характеристики функціонування системи управління фінансовими потоками з точки зору використання резерву на основі використання положень теорії масового обслуговування.The essence of financial reserve of industrial enterprise was concretized. The characteristics of performance of system of financial flows servicing on the basis of theory of queues with usage of financial reserves were defined
Loss of c-Jun N-terminal Kinase 1 and 2 Function in Liver Epithelial Cells Triggers Biliary Hyperproliferation Resembling Cholangiocarcinoma
Targeted inhibition of the c-Jun N-terminal kinases (JNKs) has shown therapeutic potential in intrahepatic cholangiocarcinoma (CCA)-related tumorigenesis. However, the cell-type-specific role and mechanisms triggered by JNK in liver parenchymal cells during CCA remain largely unknown. Here, we aimed to investigate the relevance of JNK1 and JNK2 function in hepatocytes in two different models of experimental carcinogenesis, the dethylnitrosamine (DEN) model and in nuclear factor kappa B essential modulator (NEMO)(hepatocyte-specific knockout (Deltahepa)) mice, focusing on liver damage, cell death, compensatory proliferation, fibrogenesis, and tumor development. Moreover, regulation of essential genes was assessed by reverse transcription polymerase chain reaction, immunoblottings, and immunostainings. Additionally, specific Jnk2 inhibition in hepatocytes of NEMO(Deltahepa)/JNK1(Deltahepa) mice was performed using small interfering (si) RNA (siJnk2) nanodelivery. Finally, active signaling pathways were blocked using specific inhibitors. Compound deletion of Jnk1 and Jnk2 in hepatocytes diminished hepatocellular carcinoma (HCC) in both the DEN model and in NEMO(Deltahepa) mice but in contrast caused massive proliferation of the biliary ducts. Indeed, Jnk1/2 deficiency in hepatocytes of NEMO(Deltahepa) (NEMO(Deltahepa)/JNK(Deltahepa)) animals caused elevated fibrosis, increased apoptosis, increased compensatory proliferation, and elevated inflammatory cytokines expression but reduced HCC. Furthermore, siJnk2 treatment in NEMO(Deltahepa)/JNK1(Deltahepa) mice recapitulated the phenotype of NEMO(Deltahepa)/JNK(Deltahepa) mice. Next, we sought to investigate the impact of molecular pathways in response to compound JNK deficiency in NEMO(Deltahepa) mice. We found that NEMO(Deltahepa)/JNK(Deltahepa) livers exhibited overexpression of the interleukin-6/signal transducer and activator of transcription 3 pathway in addition to epidermal growth factor receptor (EGFR)-rapidly accelerated fibrosarcoma (Raf)-mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase (ERK) cascade. The functional relevance was tested by administering lapatinib, which is a dual tyrosine kinase inhibitor of erythroblastic oncogene B-2 (ErbB2) and EGFR signaling, to NEMO(Deltahepa)/JNK(Deltahepa) mice. Lapatinib effectively inhibited cystogenesis, improved transaminases, and effectively blocked EGFR-Raf-MEK-ERK signaling.
Conclusion: We define a novel function of JNK1/2 in cholangiocyte hyperproliferation. This opens new therapeutic avenues devised to inhibit pathways of cholangiocarcinogenesis
Butorphanol with oxygen insufflation corrects etorphine-induced hypoxaemia in chemically immobilized white rhinoceros (Ceratotherium simum)
Diabetic ketoacidosis
Diabetic ketoacidosis (DKA) is the most common acute hyperglycaemic emergency in people with diabetes mellitus. A diagnosis of DKA is confirmed when all of the three criteria are present — ‘D’, either elevated blood glucose levels or a family history of diabetes mellitus; ‘K’, the presence of high urinary or blood ketoacids; and ‘A’, a high anion gap metabolic acidosis. Early diagnosis and management are paramount to improve patient outcomes. The mainstays of treatment include restoration of circulating volume, insulin therapy, electrolyte replacement and treatment of any underlying precipitating event. Without optimal treatment, DKA remains a condition with appreciable, although largely preventable, morbidity and mortality. In this Primer, we discuss the epidemiology, pathogenesis, risk factors and diagnosis of DKA and provide practical recommendations for the management of DKA in adults and children
First host record and description of female Halictophagus calcaratus Pasteels (Strepsiptera: Insecta) from South Africa
The strepsipteran, Halictophagus calcaratus, was described from South Africa by Pasteels in 1958, but no host record/s or females were included. Here we record that H. calcaratus parasitizes the cicadellid, Molopopterus theae Theron 1978, an important pest of the commercially produced shrub, Aspalathus linearis (Fabaceae), from which ‘Rooibos’ tea is produced. We provide a redescription of the male and a description of the female and the male cephalotheca. A checklist of South African Strepsiptera is included
Phenology and behaviour of the clearwing moth, Monopetalotaxis candescens (Lepidoptera: Sesiidae), associated with cultivated rooibos, Aspalathus linearis (Fabaceae), in South Africa
Production of 'rooibos' or red bush tea from Aspalathus linearis (Burman f.) Dahlgren (Fabaceae) is unique within the greater Cederberg region, Western Cape Province, South Africa. One of the principal insect pests associated with A. linearis production is the root-boring clearwing moth, Monopetalotaxis candescens Felder & Felder (Lepidoptera: Sesiidae). Annual moth flights peak during November/December, resulting in young plantations being targeted during the hot, dry summer conditions prevailing at this time. Average infestation levels progressively increased from 28 ± 2 % in year 1, to 53 ± 2 % and 72 ± 1 % in years 2 and 3, respectively. A second, 4-6 years old plantation during the three-year survey period was found to be severely infested (average 92 ± 1 %) with virtually no additional infestation over time. Estimated losses to borer infestation were calculated at 4, 24, 27 and 36 % in plantations that were 1-4 years old, respectively. Significantly more eggs were laid on leaves (66 ± 4 %) compared to woody tissue, stems and twigs. Most eggs hatched between 02:00 and 04:00, with neonates migrating down to the stem base and entering the root just below the soil surface. A control strategy, exploiting aspects of neonate migratory and feeding behaviour, should result in both yield increases and prolonged survival of plantations beyond the typical 4-5-year cycle.Articl
First host record and description of female Halictophagus calcaratus Pasteels (Strepsiptera: Insecta) from South Africa
The strepsipteran, Halictophagus calcaratus, was described from South Africa by Pasteels in 1958, but no host record/s or females were included. Here we record that H. calcaratus parasitizes the cicadellid, Molopopterus theae Theron 1978, an important pest of the commercially produced shrub, Aspalathus linearis (Fabaceae), from which ‘Rooibos’ tea is produced. We provide a redescription of the male and a description of the female and the male cephalotheca. A checklist of South African Strepsiptera is included
p25 alpha is flexible but natively folded and binds tubulin with oligomeric stoichiometry
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