Due South: a first assessment of the potential impacts of climate change on Cape vulture occurrence

Multiple anthropogenic threats have caused vulture populations to decline globally, with serious ecological and socio-economic implications. The Cape vulture (Gyps coprotheres) has declined throughout its range in southern Africa, recently being listed as extinct as a breeding species in Namibia. It has been suggested that climate change might have contributed to the decline of Cape vultures in northern parts of the range. To provide a first assessment of the potential impacts of climate change on the occurrence of Cape vultures, a presence-only ecological niche modelling method (Maxent) was used to predict the spatial occurrence patterns of wild-caught vultures fitted with GPS tracking units in northern Namibia and northern South Africa, under current and future climatic conditions. The models showed high predictive power (AUC >0.868±0.006), with precipitation seasonality and other bioclimatic variables identified as the most important variables for predicting Cape vulture presence. Of the area estimated to be suitable for Cape vultures under current conditions, 28-55% was predicted to become unsuitable under future climate conditions, with a pole-ward shift in the mean centre of the range of 151-333 km and significant range loss from the former breeding range in north-central Namibia and the core breeding range in northern South Africa. Expansions of suitable conditions into areas where the species has been historically absent in the south of the range were also predicted. The coverage of predicted suitable areas by protected areas was predicted to decrease from 5.8-7.9% to 2.8-3.8%, suggesting that private land will become increasingly important for Cape vulture conservation

Quantifying the Multivariate ENSO Index (MEI) coupling to CO2 concentration and to the length of day variations

The El Ni\~no Southern Oscillation (ENSO) is the Earth's strongest climate fluctuation on inter-annual time-scales and has global impacts although originating in the tropical Pacific. Many point indices have been developed to describe ENSO but the Multivariate ENSO Index (MEI) is considered the most representative since it links six different meteorological parameters measured over the tropical Pacific. Extreme values of MEI are correlated to the extreme values of atmospheric CO2 concentration rate variations and negatively correlated to equivalent scale extreme values of the length of day (LOD) rate variation. We evaluate a first order conversion function between MEI and the other two indexes using their annual rate of variation. The quantification of the strength of the coupling herein evaluated provides a quantitative measure to test the accuracy of theoretical model predictions. Our results further confirm the idea that the major local and global Earth-atmosphere system mechanisms are significantly coupled and synchronized to each other at multiple scales.Comment: Theoretical Applied Climatology (2012

The porin and the permeating antibiotic: A selective diffusion barrier in gram-negative bacteria

Gram-negative bacteria are responsible for a large proportion of antibiotic resistant bacterial diseases. These bacteria have a complex cell envelope that comprises an outer membrane and an inner membrane that delimit the periplasm. The outer membrane contains various protein channels, called porins, which are involved in the influx of various compounds, including several classes of antibiotics. Bacterial adaptation to reduce influx through porins is an increasing problem worldwide that contributes, together with efflux systems, to the emergence and dissemination of antibiotic resistance. An exciting challenge is to decipher the genetic and molecular basis of membrane impermeability as a bacterial resistance mechanism. This Review outlines the bacterial response towards antibiotic stress on altered membrane permeability and discusses recent advances in molecular approaches that are improving our knowledge of the physico-chemical parameters that govern the translocation of antibiotics through porin channel

Investigating the role of c-Jun N-terminal kinases in the proliferation of Werner syndrome fibroblasts using diaminopyridine inhibitors

Fibroblasts derived from the progeroid Werner syndrome show reduced replicative lifespan and a "stressed" morphology, both alleviated using the MAP kinase inhibitor SB203580. However, interpretation of these data is problematical because although SB203580 has the stress-activated kinases p38 and JNK1/2 as its preferred targets, it does show relatively low overall kinase selectivity. Several lines of data support a role for both p38 and JNK1/2 activation in the control of cellular proliferation and also the pathology of diseases of ageing, including type II diabetes, diseases to which Werner Syndrome individuals are prone, thus making the use of JNK inhibitors attractive as possible therapeutics. We have thus tested the effects of the widely used JNK inhibitor SP600125 on the proliferation and morphology of WS cells. In addition we synthesised and tested two recently described aminopyridine based inhibitors. SP600125 treatment resulted in the cessation of proliferation of WS cells and resulted in a senescent-like cellular phenotype that does not appear to be related to the inhibition of JNK1/2. In contrast, use of the more selective aminopyridine CMPD 6o at concentrations that fully inhibit JNK1/2 had a positive effect on cellular proliferation of immortalised WS cells, but no effect on the replicative lifespan of primary WS fibroblasts. In addition, CMPD 6o corrected the stressed WS cellular morphology. The aminopyridine CMPD 6r, however, had little effect on WS cells. CMDP 6o was also found to be a weak inhibitor of MK2, which may partially explain its effects on WS cells, since MK2 is known to be involved in regulating cellular morphology via HSP27 phosphorylation, and is thought to play a role in cell cycle arrest. These data suggest that total JNK1/2 activity does not play a substantial role in the proliferation control in WS cells

Azithromycin in the extremely low birth weight infant for the prevention of Bronchopulmonary Dysplasia: a pilot study

<p>Abstract</p> <p>Background</p> <p>Azithromycin reduces the severity of illness in patients with inflammatory lung disease such as cystic fibrosis and diffuse panbronchiolitis. Bronchopulmonary dysplasia (BPD) is a pulmonary disorder which causes significant morbidity and mortality in premature infants. BPD is pathologically characterized by inflammation, fibrosis and impaired alveolar development. The purpose of this study was to obtain pilot data on the effectiveness and safety of prophylactic azithromycin in reducing the incidence and severity of BPD in an extremely low birth weight (≤ 1000 grams) population.</p> <p>Methods</p> <p>Infants ≤ 1000 g birth weight admitted to the University of Kentucky Neonatal Intensive Care Unit (level III, regional referral center) from 9/1/02-6/30/03 were eligible for this pilot study. The pilot study was double-blinded, randomized, and placebo-controlled. Infants were randomized to treatment or placebo within 12 hours of beginning mechanical ventilation (IMV) and within 72 hours of birth. The treatment group received azithromycin 10 mg/kg/day for 7 days followed by 5 mg/kg/day for the duration of the study. Azithromycin or placebo was continued until the infant no longer required IMV or supplemental oxygen, to a maximum of 6 weeks. Primary endpoints were incidence of BPD as defined by oxygen requirement at 36 weeks gestation, post-natal steroid use, days of IMV, and mortality. Data was analyzed by intention to treat using Chi-square and ANOVA.</p> <p>Results</p> <p>A total of 43 extremely premature infants were enrolled in this pilot study. Mean gestational age and birth weight were similar between groups. Mortality, incidence of BPD, days of IMV, and other morbidities were not significantly different between groups. Post-natal steroid use was significantly less in the treatment group [31% (6/19)] vs. placebo group [62% (10/16)] (p = 0.05). Duration of mechanical ventilation was significantly less in treatment survivors, with a median of 13 days (1–47 days) vs. 35 days (1–112 days)(p = 0.02).</p> <p>Conclusion</p> <p>Our study suggests that azithromycin prophylaxis in extremely low birth weight infants may effectively reduce post-natal steroid use for infants. Further studies are needed to assess the effects of azithromycin on the incidence of BPD and possible less common side effects, before any recommendations regarding routine clinical use can be made.</p

The apoptotic response in HCT116BAX-/- cancer cells becomes rapidly saturated with increasing expression of a GFP-BAX fusion protein

Abstract Background Many chemotherapeutic agents promote tumor cell death by activating the intrinsic pathway of apoptosis. Intrinsic apoptosis involves permeabilization of the mitochondrial outer membrane and the release of cytochrome c, a process that is controlled by proteins of the BCL2 gene family. Chemoresistance is often associated with abnormalities in concentrations of BCL2 family proteins. Although stoichiometirc interactions between anti-apoptotic and BH3-only BCL2 family proteins have been well documented as affecting cell death, the association between changes in BAX concentration and intrinsic apoptosis are poorly understood. Methods Exogenous GFP-murine Bax fusion constructs were transfected into BAX-deficient HCT116 cells. To titrate the expression of the fusion protein, GFP-BAX was cloned into a tetracycline sensitive expression cassette and cotransfected with a plasmid expressing the rtTA transcription factor into HCT116 BAX-/- cells. Linear expression of the fusion gene was induced with doxycycline and monitored by quantitative PCR and immunoblotting. Cell death was assayed by DAPI staining cells after exposure to indomethacin, and scoring nuclei for condensed chromatin and fragmented nuclei. Results HCT116 BAX-/- cells were resistant to indomethacin, but susceptibility could be recovered in cells expressing a GFP-BAX fusion protein. Titration of GFP-BAX expression revealed that the concentration of BAX required to induce a saturating apoptosis response from baseline, was rapidly achieved. Increased levels of GFP-BAX were unable to stimulate higher levels of cell death. Examination of GFP-BAX distribution before and after indomethacin treatment indicated that BAX protein did not form aggregates when present at sub-lethal concentrations. Conclusion Within the limitations of this experimental system, BAX-dependent apoptosis in HCT116 cells exhibits an all-or-none response depending on the level of BAX protein present. The lack of BAX aggregation at sub-saturation levels suggests that the translocation step of BAX activation may be impaired

A survey of the anti-apoptotic Bcl-2 subfamily expression in cancer types provides a platform to predict the efficacy of Bcl-2 antagonists in cancer therapy

We investigated the mRNA expression levels of all six antiapoptotic Bcl-2 subfamily members in 68 human cancer cell lines using qPCR techniques and measured the ability of known Bcl-2 inhibitors to induce cell death in 36 of the studied tumor cell lines. Our study reveals that Mcl-1 represents the anti-apoptotic Bcl-2 subfamily member with the highest mRNA levels in the lung, prostate, breast, ovarian, renal, and glioma cancer cell lines. In leukemia/lymphoma and melanoma cancer cell lines, Bcl-2 and Bfl-1 had the highest levels of mRNA, respectively. The observed correlation between the cell killing properties of known Bcl-2 inhibitors and the relative mRNA expression levels of anti-apoptotic Bcl-2 proteins provide critical insights into apoptosis-based anticancer strategies that target Bcl-2 proteins. Our data may explain current challenges of selective Bcl-2 inhibitors in the clinic, given that severe expression of Bcl-2 seems to be limited to leukemia cell lines. Furthermore, our data suggest that in most cancer types a strategy targeted to Mcl-1 inhibition, or combination of Bfl-1 and Mcl-1 inhibition for melanoma, may prove to be more successful than therapies targeting only Bcl-2

Antitumor activity and mechanisms of action of total glycosides from aerial part of Cimicifuga dahurica targeted against hepatoma

<p>Abstract</p> <p>Background</p> <p>Medicinal plant is a main source of cancer drug development. Some of the cycloartane triterpenoids isolated from the aerial part of <it>Cimicifuga dahurica </it>showed cytotoxicity in several cancer cell lines. It is of great interest to examine the antiproliferative activity and mechanisms of total triterpenoid glycosides of <it>C. dahurica </it>and therefore might eventually be useful in the prevention or treatment of Hepatoma.</p> <p>Methods</p> <p>The total glycosides from the aerial part (TGA) was extracted and its cytotoxicity was evaluated in HepG2 cells and primary cultured normal mouse hepatocytes by an MTT assay. Morphology observation, Annexin V-FITC/PI staining, cell cycle analysis and western blot were used to further elucidate the cytotoxic mechanism of TGA. Implanted mouse H₂₂hepatoma model was used to demonstrate the tumor growth inhibitory activity of TGA <it>in vivo</it>.</p> <p>Results</p> <p>The IC₅₀values of TGA in HepG2 and primary cultured normal mouse hepatocytes were 21 and 105 μg/ml, respectively. TGA induced G₀/G₁cell cycle arrest at lower concentration (25 μg/ml), and triggered G₂/M arrest and apoptosis at higher concentrations (50 and 100 μg/ml respectively). An increase in the ratio of Bax/Bcl-2 was implicated in TGA-induced apoptosis. In addition, TGA inhibited the growth of the implanted mouse H₂₂tumor in a dose-dependent manner.</p> <p>Conclusion</p> <p>TGA may potentially find use as a new therapy for the treatment of hepatoma.</p

Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente