Fence and plough for Lapwings: Nest protection to improve nest and chick survival in Swiss farmland
- Switzerland had up to 1000 Lapwing pairs breeding in the 1970s. Actually, there are some 200. The crash was mainly due to a poor productivity of 0.2 to 0.4 fledglings per pair and year. To achieve a fledging rate of at least 0.8 required for population stability, a Recovery Programme was initiated to support a small population of 10-25 pairs breeding in central Switzerland. In 2004 to 2006 all nests were marked and spared during field labour by the farmers. As a result of a well established cooperation with the local farmers, not a single nest was destroyed by agricultural activities. However, there was a high risk of nest desertion when farming activities took place during the period of egg laying. Therefore, it might be worth to postpone field labour for some days to allow clutch completion. In 2005 and 2006, but not in 2004, most nests were protected from ground predators by surrounding entire fields rather than individual clutches with electro-fences as used in sheep farming. While 95 % of clutches within the fences hatched successfully, 61 % of unprotected nests were predated. In 2006 the influence of predation on chick survival was investigated by radio-tagging 81 chicks soon after hatching. They had no difficulties to cross the electro-fences. Predation occurred mostly at night (73 %) and outside the fences (87 %). Of 46 chicks predated at night only one was taken inside an electro-fence. Daytime predation played a minor role (27 % of all chick predations) and occurred at the same rate inside and outside the electro-fence. Reproductive success in 2005 was an estimated 0.8 fledging young per pair and year. In 2006, however, it dropped to 0.25 due to heavy chick predation.
Contribution of mixing to the upward transport across the TTL
Fábio Henrique Silva dos Santos
Laura L. Pan
- During the second part of the TROCCINOX campaign that took place in Brazil in early 2005, chemical species were measured on-board of the high altitude research aircraft Geophysica (ozone, water vapor, NO, NOy, CH4 and CO) in the altitude range up to 20 km (or up to 450 K potential temperature), i.e. spanning the TTL region roughly extending between 350 and 420 K.
Analysis of transport across TTL is performed using a new version of the Chemical Lagrangian Model of the Stratosphere (CLaMS). In this new version, the stratospheric model has been extended to the earth surface. Above the tropopause, the isentropic and cross-isentropic advection in CLaMS is driven by ECMWF winds and heating/cooling rates derived from a radiation calculation. Below the tropopause the model smoothly transforms from the isentropic to hybrid-pressure coordinate and, in this way, takes into account the effect of large-scale convective transport as implemented in the ECMWF vertical wind. As with other CLaMS simulations, the irreversible transport, i.e. mixing, is controlled by the local horizontal strain and vertical shear rates.
Stratospheric and tropospheric signatures in the TTL can be seen both in the observation and in the model. The composition of air above ≈350 K is mainly controlled by mixing on a time scale of weeks or even months. Based on CLaMS transport studies where mixing can be completely switched off, we deduce that vertical mixing, mainly driven by the vertical shear in the outflow regions of the large-scale convection and in the vicinity of the subtropical jets, is necessary to understand the upward transport of the tropospheric air from the main convective outflow around 350 K up to the tropical tropopause around 380 K. This mechanism is most effective if the outflow of the mesoscale convective systems interacts with the subtropical jets.
IAP-IAP complexes required for apoptosis resistance of C. trachomatis-infected cells
- Host cells infected with obligate intracellular bacteria Chlamydia trachomatis are profoundly resistant to diverse apoptotic stimuli. The molecular mechanisms underlying the block in apoptotic signaling of infected cells is not well understood. Here we investigated the molecular mechanism by which apoptosis induced via the tumor necrosis factor (TNF) receptor is prevented in infected epithelial cells. Infection with C. trachomatis leads to the up-regulation of cellular inhibitor of apoptosis (cIAP)-2, and interfering with cIAP-2 up-regulation sensitized infected cells for TNF-induced apoptosis. Interestingly, besides cIAP-2, cIAP-1 and X-linked IAP, although not differentially regulated by infection, are required to maintain apoptosis resistance in infected cells. We detected that IAPs are constitutively organized in heteromeric complexes and small interfering RNA-mediated silencing of one of these IAPs affects the stability of another IAP. In particular, the stability of cIAP-2 is modulated by the presence of X-linked IAP and their interaction is stabilized in infected cells. Our observations suggest that IAPs are functional and stable as heteromers, a thus far undiscovered mechanism of IAP regulation and its role in modulation of apoptosis.
Arteriogenesis versus angiogenesis: similarities and differences
- Cardiovascular diseases account for more than half of total mortality before the age of 75 in industrialized countries. To develop therapies promoting the compensatory growth of blood vessels could be superior to palliative surgical surgical interventions. Therefore, much effort has been put into investigating underlying mechanisms. Depending on the initial trigger, growth of blood vessels in adult organisms proceeds via two major processes, angiogenesis and arteriogenesis. While angiogenesis is induced by hypoxia and results in new capillaries, arteriogenesis is induced by physical forces, most importantly fluid shear stress. Consequently, chronically elevated fluid shear stress was found to be the strongest trigger under experimental conditions. Arteriogenesis describes the remodelling of pre-existing arterio-arteriolar anastomoses to completely developed and functional arteries. In both growth processes, enlargement of vascular wall structures was proposed to be covered by proliferation of existing wall cells. Recently, increasing evidence emerges, implicating a pivotal role for circulating cells, above all blood monocytes, in vascular growth processes. Since it has been shown that monocytes/macrophage release a cocktail of chemokines, growth factors and proteases involved in vascular growth, their contribution seems to be of a paracrine fashion. A similar role is currently discussed for various populations of bone-marrow derived stem cells and endothelial progenitors. In contrast, the initial hypothesis that these cells -after undergoing a (trans-)differentiation- contribute by a structural integration into the growing vessel wall, is increasingly challenged.
Australasian Arachnology, Number 75, September 2006
- Again, this issue is a bit late
(September instead of August) but I hope
the diverse and exciting contents will
make up for the delay. As per usual, the
Australian Arachnological Society is
grateful to all who contributed to this
issue! More excitingly, I already have
articles for the December issue. Stay
tuned for an update on the taxonomy of
Australian jumping spiders by Marek
QCD equation of state and dark matter
- The QCD equation of state is not often discussed in cosmology. However, the relic density of
weakly interacting massive particles (WIMPs) depends on the entropy and the expansion rate of
the Universe when they freeze out, at a temperature in the range 400 MeV – 40GeV, where QCD
corrections are still important. We use recent analytic and lattice calculations of the QCD pressure
to produce a new equation of state suitable for use in relic density calculations. As an example,
we show that relic densities calculated by the dark matter package DarkSUSY receive corrections
of several per cent, within the observational accuracy of the Planck CMB mission, due for launch
short @nd sweet news : Nr. 6
- * Curriculum - "Case Management in General Medical Care"
* DEGAM Guideline Nr. 9 on Congestive Heart Failure to be published
* "Chronic Care" - an update
* PRoMPT Project recruits 609 patients
* Medicine is an Art which approximates Science
short @nd sweet news : Nr. 5
- * Training physicians judged excellent by students!
* Medical history compilation and discussion guidance
* New online databank for reporting system "every error counts"
* Error research to be continued - Practices wanted!
Chasing the Unicorn: RHIC and the QGP
Robert D. Pisarski
- At nonzero temperature, it is expected that QCD undergoes a phase transition to a deconfined, chirally symmetric phase, the Quark-Gluon Plasma (QGP). I review what we expect theoretically about this possible transition, and what we have learned from heavy ion experiments at RHIC. I argue that while there are unambiguous signals for qualitatively new behavior at RHIC, versus experiments at lower energies, that in detail, no simple theoretical model can explain all salient features of the data.
Gorilla journal : nr. 33 / journal of Berggorilla- & Regenwald-Direkthilfe