Sequestered Alkaloid Defenses in the Dendrobatid Poison Frog Oophaga pumilio Provide Variable Protection from Microbial Pathogens

Most amphibians produce their own defensive chemicals; however, poison frogs sequester their alkaloid-based defenses from dietary arthropods. Alkaloids function as a defense against predators, and certain types appear to inhibit microbial growth. Alkaloid defenses vary considerably among populations of poison frogs, reflecting geographic differences in availability of dietary arthropods. Consequently, environmentally driven differences in frog defenses may have significant implications regarding their protection against pathogens. While natural alkaloid mixtures in dendrobatid poison frogs have recently been shown to inhibit growth of non-pathogenic microbes, no studies have examined the effectiveness of alkaloids against microbes that infect these frogs. Herein, we examined how alkaloid defenses in the dendrobatid poison frog, Oophaga pumilio, affect growth of the known anuran pathogens Aeromonas hydrophila and Klebsiella pneumoniae. Frogs were collected from five locations throughout Costa Rica that are known to vary in their alkaloid profiles. Alkaloids were isolated from individual skins, and extracts were assayed against both pathogens. Microbe subcultures were inoculated with extracted alkaloids to create dose-response curves. Subsequent spectrophotometry and cell counting assays were used to assess growth inhibition. GC-MS was used to characterize and quantify alkaloids in frog extracts, and our results suggest that variation in alkaloid defenses lead to differences in inhibition of these pathogens. The present study provides the first evidence that alkaloid variation in a dendrobatid poison frog is associated with differences in inhibition of anuran pathogens, and offers further support that alkaloid defenses in poison frogs confer protection against both pathogens and predators

The benthic carbon mineralization on a global scale

In this study we present a global distribution pattern and budget of the minimum flux of particulate organic carbon to the sea floor (JPOCα). The estimations are based on regionally specific correlations between the diffusive oxygen flux across the sediment-water interface, the total organic carbon content in surface sediments, and the oxygen concentration in bottom waters. For this, we modified the principal equation of Cai and Reimers [1995] as a basic monod reaction rate, applied within 11 regions where in situ measurements of diffusive oxygen uptake exist. By application of the resulting transfer functions to other regions with similar sedimentary conditions and areal interpolation, we calculated a minimum global budget of particulate organic carbon that actually reaches the sea floor of ∼0.5 GtC yr−1 (>1000 m water depth (wd)), whereas approximately 0.002–0.12 GtC yr−1 is buried in the sediments (0.01–0.4% of surface primary production). Despite the fact that our global budget is in good agreement with previous studies, we found conspicuous differences among the distribution patterns of primary production, calculations based on particle trap collections of the POC flux, and JPOCα of this study. These deviations, especially located at the southeastern and southwestern Atlantic Ocean, the Greenland and Norwegian Sea and the entire equatorial Pacific Ocean, strongly indicate a considerable influence of lateral particle transport on the vertical link between surface waters and underlying sediments. This observation is supported by sediment trap data. Furthermore, local differences in the availability and quality of the organic matter as well as different transport mechanisms through the water column are discussed

The invasive kudzu bug, Megacopta cribraria (Hemiptera: Plataspidae) as an agricultural and nuisance pest

The invasive “kudzu bug,” Megacopta cribraria (Hemiptera: Plataspidae) is a native of Asia that was found in northeastern Georgia in fall 2009. This insect has since spread rapidly throughout the southeastern U.S., and is abundant in much of South Carolina. Megacopta cribraria feed on the vascular fluid of several legumes, primarily kudzu, Puereria montana var. lobata, and soybeans, Glycine max. These insects enter soybean fields in often alarming numbers, leaving conspicuous lesions on soybean stems and potentially reducing yields. In addition, M. cribraria congregate on homes and other structures in late fall as they seek overwintering sites, potentially becoming a nuisance pest where populations are large. We examined M. cribraria as a yield reducing pest of soybeans and as a nuisance pest of buildings. Large populations of M. cribraria in caged soybean plots resulted in yield losses of up to 59.6%, and yield reductions were similar in both 2011 and 2012. Several professional-use insecticides were effective in controlling M. cribraria on a variety of building material surfaces, and in some insecticide × surface combinations activity was maintained 30 days post-application. These results contribute to our still developing understanding of this insect as an agricultural and nuisance pest

Управление дебиторской задолженностью на предприятии электроэнергетики

Цель работы – разработка практических рекомендаций по совершенствованию управления дебиторской задолженностью АО "Тюменьэнерго". В процессе исследования проводились определение организационно-экономической характеристики предприятия электроэнергетики АО "Тюменьэнерго", анализ финансового состояния предприятия, анализ дебиторской задолженности, изучение управления дебиторской задолженностью АО "Тюменьэнерго". В результате исследования был установлен ряд проблем на предприятии, для решения которых предложены рекомендации по совершенствованию управления дебиторской задолженностью. По результатам расчета показателей эффективности управления дебиторской задолженностью обоснована эффективность применения рекомендации для АО "Тюменьэнерго".The aim of the work is to develop practical recommendations for improving the management of accounts receivable of JSC "Tyumenenergo". During investigations it was carried out the definition of organizational and economic characteristics of the electricity company JSC "Tyumenenergo", the analysis of the financial condition of the company, the accounts receivable analysis, the study of receivables management of JSC "Tyumenenergo". The investigations of the company detected a number of problems, for which the recommendations for improving the management of accounts receivable were suggested. According to the results of calculation of management indicators receivable it was proved the effectiveness of the recommendations for the JSC "Tyumenenergo"

'Surely the most natural scenario in the world’: Representations of ‘Family’ in BBC Pre-school Television

Historically, the majority of work on British children’s television has adopted either an institutional or an audience focus, with the texts themselves often overlooked. This neglect has meant that questions of representation in British children’s television – including issues such as family, gender, class or ethnicity - have been infrequently analysed in the UK context. In this article, we adopt a primarily qualitative methodology and analyse the various textual manifestations of ‘family’, group, or community as represented in a selected number of BBC pre-school programmes. In doing so, we question the (limited amount of) international work that has examined representations of the family in children’s television, and argue that nuclear family structures do not predominate in this sphere

Temozolomide and cisplatin in relapsed/refractory acute leukemia

Cisplatin depletes MGMT and increases the sensitivity of leukemia cells to temozolomide. We performed a phase I study of cisplatin and temozolomide in patients with relapsed and refractory acute leukemia. Fifteen patients had AML, 3 had ALL, and 2 had biphenotypic leukemia. The median number of prior chemotherapy regimens was 3 (1–5). Treatment was well tolerated up to the maximal doses of temozolomide 200 mg/m2/d times 7 days and cisplatin 100 mg/m2 on day 1. There was one complete remission in this heavily pretreated patient population. Five of 20 (25%) patients demonstrated a significant reduction in bone marrow blasts

Major immunophenotypic abnormalities in patients with primary adrenal insufficiency of different etiology

INTRODUCTION Patients with primary adrenal insufficiency (PAI) suffer from increased risk of infection, adrenal crises and have a higher mortality rate. Such dismal outcomes have been inferred to immune cell dysregulation because of unphysiological cortisol replacement. As the immune landscape of patients with different types of PAI has not been systematically explored, we set out to immunophenotype PAI patients with different causes of glucocorticoid (GC) deficiency. METHODS This cross-sectional single center study includes 28 patients with congenital adrenal hyperplasia (CAH), 27 after bilateral adrenalectomy due to Cushing's syndrome (BADx), 21 with Addison's disease (AD) and 52 healthy controls. All patients with PAI were on a stable GC replacement regimen with a median dose of 25 mg hydrocortisone per day. Peripheral blood mononuclear cells were isolated from heparinized blood samples. Immune cell subsets were analyzed using multicolor flow cytometry after four-hour stimulation with phorbol myristate acetate and ionomycin. Natural killer (NK-) cell cytotoxicity and clock gene expression were investigated. RESULTS The percentage of T helper cell subsets was downregulated in AD patients (Th1 p = 0.0024, Th2 p = 0.0157, Th17 p < 0.0001) compared to controls. Cytotoxic T cell subsets were reduced in AD (Tc1 p = 0.0075, Tc2 p = 0.0154) and CAH patients (Tc1 p = 0.0055, Tc2 p = 0.0012) compared to controls. NKCC was reduced in all subsets of PAI patients, with smallest changes in CAH. Degranulation marker CD107a expression was upregulated in BADx and AD, not in CAH patients compared to controls (BADx p < 0.0001; AD p = 0.0002). In contrast to NK cell activating receptors, NK cell inhibiting receptor CD94 was upregulated in BADx and AD, but not in CAH patients (p < 0.0001). Although modulation in clock gene expression could be confirmed in our patient subgroups, major interindividual-intergroup dissimilarities were not detected. DISCUSSION In patients with different etiologies of PAI, distinct differences in T and NK cell-phenotypes became apparent despite the use of same GC preparation and dose. Our results highlight unsuspected differences in immune cell composition and function in PAI patients of different causes and suggest disease-specific alterations that might necessitate disease-specific treatment

Immunological changes in nestlings growing under predation risk

Predation is one of the most relevant selective forces in nature. However, the physiological mechanisms behind anti-predator strategies have been overlooked, despite their importance to understand predator-prey interactions. In this context, the immune system could be especially revealing due to its relationship with other critical functions and its ability to enhance prey's probabilities of survival to a predator's attack. Developing organisms (e.g. nestlings) are excellent models to study this topic because they suffer a high predation pressure while undergoing the majority of their development, which maximizes potential trade-offs between immunity and other biological functions. Using common blackbirds Turdus merula as model species, we experimentally investigated whether an elevated nest predation risk during the nestling period affects nestlings' immunity and its possible interactions with developmental conditions (i.e. body condition and growth). Experimental nestlings modified some components of their immunity, but only when considering body condition and growth rate, indicating a multifaceted immunological response to predation risk and an important mediator role of nestlings' developmental conditions. Predation risk induced a suppression of IgY but an increase in lymphocytes in nestlings with poor body condition. In addition, experimental but not control nestlings showed a negative correlation between growth and heterophils, demonstrating that nest predation risk can affect the interaction between growth and immunity. This study highlights the importance of immunity in anti-predator response in nestlings and shows the relevance of including physiological components to the study of predation risk.</p