A socio‐ecological model for predicting impacts of land‐use and climate change on regional plant diversity in the Austrian Alps

Climate and land‐use change jointly affect the future of biodiversity. Yet, biodiversity scenarios have so far concentrated on climatic effects because forecasts of land use are rarely available at appropriate spatial and thematic scales. Agent‐based models (ABMs) represent a potentially powerful but little explored tool for establishing thematically and spatially fine‐grained land‐use scenarios. Here, we use an ABM parameterized for 1,329 agents, mostly farmers, in a Central European model region, and simulate the changes to land‐use patterns resulting from their response to three scenarios of changing socio‐economic conditions and three scenarios of climate change until the mid of the century. Subsequently, we use species distribution models to, first, analyse relationships between the realized niches of 832 plant species and climatic gradients or land‐use types, respectively, and, second, to project consequent changes in potential regional ranges of these species as triggered by changes in both the altered land‐use patterns and the changing climate. We find that both drivers determine the realized niches of the studied plants, with land use having a stronger effect than any single climatic variable in the model. Nevertheless, the plants' future distributions appear much more responsive to climate than to land‐use changes because alternative future socio‐economic backgrounds have only modest impact on land‐use decisions in the model region. However, relative effects of climate and land‐use changes on biodiversity may differ drastically in other regions, especially where landscapes are still dominated by natural or semi‐natural habitat. We conclude that agent‐based modelling of land use is able to provide scenarios at scales relevant to individual species distribution and suggest that coupling ABMs with models of species' range change should be intensified to provide more realistic biodiversity forecasts.     

The Role of Social Context in Shaping Student-Athlete Opinions

How do student-athletes form opinions? This is a particularly important question given ongoing debates about whether student-athletes should be paid and/or allowed to unionize. These debates concern the rights and benefits accrued directly to student-athletes, and thus, understanding their attitudes is of obvious import. Yet, virtually no recent work has delved into how student-athletes form opinions on these issues. We fill this gap with a theoretical framework that predicts changes in social context alter opinions. This leads to the hypothesis that opinions will change once a student-athlete completes his/her career and finds him/herself in a distinct social network. We test the prediction with a survey, implemented in 2012, of one of the most notable athletic conferences in the National Collegiate Athletic Association (NCAA): the Big Ten. We find that post-career student-athletes demonstrate higher levels of support for pay for play and unionization. Our results suggest that student-athletes'' opinions seem to depend on their extant social contexts. While our data, from 2012, neither speak to current opinions – given the quickly evolving landscape of college athletics – nor demonstrate what reforms may be “best,” they do accentuate the power of social context in shaping student-athletes'' attitudes.     

Assessing Archeal Indicators of Performance by RT-qPCR Methods During Anaerobic Co-digestion of Organic Wastes

Biogas is a renewable energy resource produced during the anaerobic digestion of various organic substrates. A wide community of microorganisms is involved, including methanogens. These Archaea are the biologic key to the process because they accomplish the methane-forming reaction. Despite its crucial role, the microbiome inside the digester is poorly understood. The aim of this work is to develop bioindicators of efficiency for the anaerobic process through the quantification and characterisation of the methanogens and sulphate-reducing bacteria. From a full-scale digester fed with organic wastes, 31 samples were collected. Temperature, pH, acidity, alkalinity and biogas quantity and quality were monitored over time. The methanogens were detected from the samples both in total and as belonging to different taxa units. These evaluations, by real-time quantitative PCR (RT-qPCR) methods, produced valuable results for Methanosarcina, Methanosaeta, Methanocorpusculaceae and sulphate-reducing bacteria. Methanosarcina was the most abundant family, followed by Methanocorpusculaceae and then Methanosaeta. The methanogen taxa are significantly and directly correlated with each other (p?<?0.05). Methanosaeta and Methanocorpusculaceae are present in significantly different amounts at different temperatures. While Methanosaeta levels also change when the organic load increases (t test, p?<?0.05), Methanosarcina is more tolerant, and its levels are quite constant. Methanosarcina and Methanosaeta are proposed to be bioindicators of the stability of the process (the first) and of susceptibility (the second) to detect early sufferance conditions in the digester. These methods will be useful in the control and optimisation of an eco-friendly waste-to-energy system.     

CXCR1 as a novel target for directing reactive T cells toward melanoma: implications for adoptive cell transfer immunotherapy

Adoptive cell transfer therapy with reactive T cells is one of the most promising immunotherapeutic modalities for metastatic melanoma patients. Homing of the transferred T cells to all tumor sites in sufficient numbers is of great importance. Here, we seek to exploit endogenous chemotactic signals in order to manipulate and enhance the directional trafficking of transferred T cells toward melanoma. Chemokine profiling of 15 melanoma cultures shows that CXCL1 and CXCL8 are abundantly expressed and secreted from melanoma cultures. However, the complimentary analysis on 40 melanoma patient-derived tumor-infiltrating lymphocytes (TIL) proves that the corresponding chemokine receptors are either not expressed (CXCR2) or expressed at low levels (CXCR1). Using the in vitro transwell system, we demonstrate that TIL cells preferentially migrate toward melanoma and that endogenously expressing CXCR1 TIL cells are significantly enriched among the migrating lymphocytes. The role of the chemokines CXCL1 and CXCL8 is demonstrated by partial abrogation of this enrichment with anti-CXCL1 and anti-CXCL8 neutralizing antibodies. The role of the chemokine receptor CXCR1 is validated by the enhanced migration of CXCR1-engineered TIL cells toward melanoma or recombinant CXCL8. Cytotoxicity and IFNγ secretion activity are unaltered by CXCR1 expression profile. Taken together, these results mark CXCR1 as a candidate for genetic manipulations to enhance trafficking of adoptively transferred T cells. This approach is complimentary and potentially synergistic with other genetic strategies designed to enhance anti-tumor potency.     

Development of a real-time PCR method for the detection of fossil 16S rDNA fragments of phototrophic sulfur bacteria in the sediments of Lake Cadagno

Lake Cadagno is a crenogenic meromictic lake situated in the southern range of the Swiss Alps characterized by a compact chemocline that has been the object of many ecological studies. The population dynamics of phototrophic sulfur bacteria in the chemocline has been monitored since 1994 with molecular methods such as 16S rRNA gene clone library analysis. To reconstruct paleo-microbial community dynamics, we developed a quantitative real-time PCR methodology for specific detection of 16S rRNA gene sequences of purple and green sulfur bacteria populations from sediment samples. We detected fossil 16S rDNA of nine populations of phototrophic sulfur bacteria down to 9-m sediment depth, corresponding to about 9500 years of the lake's biogeological history. These results provide the first evidence for the presence of 16S rDNA of anoxygenic phototrophic bacteria in Holocene sediments of an alpine meromictic lake and indicate that the water column stratification and the bacterial plume were already present in Lake Cadagno thousands of years ago. The finding of Chlorobium clathratiforme remains in all the samples analyzed shows that this population, identified in the water column only in 2001, was already a part of the lake's biota in the past.     

Methyl palmitate: a novel product of the Medfly (Ceratitis capitata) corpus allatum

The corpus allatum (CA) of adult female Ceratitis capitata produces methyl palmitate (MP) in vitro, in addition to JHB₃ and JH III. Biosynthesized MP migrates on TLC and co-elutes from RP-18 HPLC with synthetic MP. Its identity is verified herein by GCMS. MP production is up-regulated twofold by mevastatin, an inhibitor of mevalonic acid-dependent isoprene biosynthesis. Fosmidomycin, an inhibitor of mevalonic acid-independent isoprene synthesis in graminaceous plants, up-regulates MP synthesis by about fourfold. However, it does not depress JHB₃ biosynthesis concurrently. This suggests that the initial enzyme(s) in the conversion of 1-deoxy-xylulose 5-phosphate to isoprene is presumably present in C. capitata, but is inhibited by fosmidomycin, and this inhibition diverts precursors to MP synthesis. Phytol, an acyclic diterpene, might be suppressing isoprene biosynthesis by CA, thereby resulting in a fourfold increase in the MP biosynthesis. Linolenic acid is an end-product and its presence in incubation media up-regulates MP biosynthesis by twofold, presumably due to the feedback diversion to biosynthesis of C_16:0 and its methyl ester. Biosynthesis of MP is markedly depressed after mating, while otherwise maintained at significantly higher levels in virgin females. MP biosynthesis is significantly reduced in virgin females by direct axonal control but is less consistent after mating.     

Interaction of 4-arylcoumarin analogues of combretastatins with microtubule network of HBL100 cells and binding to tubulin

The synthesis of different 4-arylcoumarin analogues of combretastatin A-4 led to the identification of two new compounds (1 and 2) with potent cytotoxic activity on a CEM leukemia cell line and a third one completely inactive (compound 3). It was suggested that the cytotoxicity of compounds 1 and 2 may be related to their interaction with microtubules and tubulin, since these compounds inhibit microtubule formation from purified tubulin in vitro [Bailly et al. (2003) J. Med. Chem. 46 (25), 5437-5444]. In the present study, tubulin was identified as the main target of these molecules. We studied structure-activity relationships of these compounds using biological experiments specific for tubulin binding. The modification of cell cycle progression induced by compounds 1 and 2 was characterized by an apoptotic induction on human breast cells (HBL100). In addition, these two molecules disturbed cell survival by depolymerizing the microtubule network, leading to a mitotic block. We then determined the thermodynamic parameters of their interaction with purified tubulin by fluorescence spectroscopy and isothermal microcalorimetry. These results, together with a superimposition of the molecule on colchicine in the X-ray-determined three-dimensional structure model of tubulin-colchicine complex, allowed us to identify the pharmacophore of the combretastatin A-4 analogues responsible for their biological activity.     

Altered Orcadian Rhythms of Blood Pressure and Heart Rate in Non-Hemodialysis Chronic Renal Failure

The extended use of ambulatory monitoring has permitted the identification of many conditions in which the circadian rhythm of blood pressure is altered. The common denominator seems to be an impairment of the autonomic nervous system function. We examined whether the circadian blood pressure rhythm is altered in chronic renal failure (where autonomic dysfunction is usually present) by using a standardized chronobiological inferential statistical method in hospitalized subjects. For this purpose, a group of 30 non-hemodialysis hypertensive patients with chronic renal failure was compared with a second group of 30 patients affected by uncomplicated mild-to-moderate essential hypertension. The two groups were matched by age, sex and circadian mesors of blood pressure. Diet, meal times, sleep and activity logs were standardized. Blood pressure and heart rate recordings were obtained by using an automatic oscillometric recorder and subsequently analyzed according to the cosinor method. A mean circadian rhythm of blood pressure was documented in both groups, but while the mean acrophases occurred between 2 and 3 p.m. in essential hypertension, in renal failure they were between 11 p.m. and midnight for blood pressure and around 7 p.m. for heart rate. In addition, the mean circadian amplitudes were significantly lower in renal failure, while the mean circadian mesor of heart rate was significantly higher. Our data demonstrate that the circadian rhythms of blood pressure and heart rate are altered also in hypertension due to chronic renal failure.