Global Monetarism and the Monetary Approach to the Balance of Payments

macroeconomics, global monetarism, monetary approach, balance of payments

Political competition and societal veto players: the politics of pension reform in Southern Europe

While Southern European countries have pursued a series of pension reforms since the early 1990s, significant variation arises across them. Focusing on the concept of political replacement risk (the probability of a government being electorally punished for pursuing a given policy) and the changes in the labor movement's organizational structure, this article seeks to elucidate the differences in reform outcomes, in Italy, Greece, Portugal and Spain. Our analysis shows that significant reforms are implemented when governments face a high political replacement risk and the labor movement has undergone changes in its structure. By contrast, governments facing a stronger labor movement will generally be less effective at passing significant reforms, unless they can secure a strong support over the necessity to implement reforms

Combined Effects of Tetrakis Hydroxymethyl Phosphonium Chloride and Ammonium on Plankton Community Structure in Blackwater Pond Mesocosms

Flame retardant chemicals enter aquatic systems through municipal and industrial wastewater, and despite being detected in surface waters, most have not been thoroughly assessed for environmental risk. Halogenated flame retardants, known to be persistent and highly toxic to aquatic organisms are being phased out, and replaced with new or under-tested organophosphorus flame retardants. Organophosphorus flame retardants, such as tetrakis hydroxymethyl phosphonium chloride (THPC), often have similar applications to and are generally not as persistent as halogenated flame retardants. Single-species toxicity tests of organophosphorus flame retardants reveal a wide range of toxicity values within the range of environmentally relevant concentrations in surface waters. Additionally, other contaminants from industry and agriculture are likely to accompany flame retardant chemicals in surface waters. For example, THPC may be found in combination with ammonia, which is released directly with THPC in textile effluent and is a common component of agricultural fertilizers. Ammonia is a form of inorganic nitrogen that can stimulate primary production, but in excess can shift phytoplankton community composition to dominance by less edible or harmful species. While the effects of excess nutrients on planktonic communities are well studied, recent findings suggest the presence of nutrients can reduce or enhance the effects of other contaminants on aquatic organisms. Floating, in situ mesocosms were dosed with two levels of THPC (0.08 and 0.8 mg L-1) with or without ammonium (0.3 mg L-1) in a fully crossed design to study the effects of THPC and ammonium in combination on plankton communities. I hypothesized that THPC and ammonium affect plankton communities differently alone than in combination. Water samples were collected weekly over four weeks to assess zooplankton community composition and phytoplankton abundance (as chlorophyll a) in response to treatment additions. The combination of THPC and ammonium influenced community composition, but each factor alone had no effect. Specifically, low THPC+ammonium decreased the proportion of calanoid copepods with a corresponding increase in rotifers due to lower predation pressure compared to each factor alone one to three weeks post exposure. Total zooplankton abundance changed over time across all treatments, decreasing by more than 50% after one and two weeks of exposure before increasing to abundances approximately 27% higher than initial by week 4. Chlorophyll a was not affected by THPC and nutrient addition, but concentrations fluctuated between 5-15 µg L-1 in all treatments throughout the duration of the experiment. The interaction of THPC and ammonium suggests that these contaminants in combination can reduce abundance of large zooplankton such as copepods, thereby limiting a food source for planktivorous fish, and releasing smaller crustacean zooplankton and rotifers from predation and competitive pressure

Spinally projecting preproglucagon axons preferentially innervate sympathetic preganglionic neurons

Glucagon-like peptide-1 (GLP-1) affects central autonomic neurons, including those controlling the cardiovascular system, thermogenesis, and energy balance. Preproglucagon (PPG) neurons, located mainly in the nucleus tractus solitarius (NTS) and medullary reticular formation, produce GLP-1. In transgenic mice expressing glucagon promoter-driven yellow fluorescent protein (YFP), these brainstem PPG neurons project to many central autonomic regions where GLP-1 receptors are expressed. The spinal cord also contains GLP-1 receptor mRNA but the distribution of spinal PPG axons is unknown. Here, we used two-color immunoperoxidase labeling to examine PPG innervation of spinal segments T1–S4 in YFP-PPG mice. Immunoreactivity for YFP identified spinal PPG axons and perikarya. We classified spinal neurons receiving PPG input by immunoreactivity for choline acetyltransferase (ChAT), nitric oxide synthase (NOS) and/or Fluorogold (FG) retrogradely transported from the peritoneal cavity. FG microinjected at T9 defined cell bodies that supplied spinal PPG innervation. The deep dorsal horn of lower lumbar cord contained YFP-immunoreactive neurons. Non-varicose, YFP-immunoreactive axons were prominent in the lateral funiculus, ventral white commissure and around the ventral median fissure. In T1–L2, varicose, YFP-containing axons closely apposed many ChAT-immunoreactive sympathetic preganglionic neurons (SPN) in the intermediolateral cell column (IML) and dorsal lamina X. In the sacral parasympathetic nucleus, about 10% of ChAT-immunoreactive preganglionic neurons received YFP appositions, as did occasional ChAT-positive motor neurons throughout the rostrocaudal extent of the ventral horn. YFP appositions also occurred on NOS-immunoreactive spinal interneurons and on spinal YFP-immunoreactive neurons. Injecting FG at T9 retrogradely labeled many YFP-PPG cell bodies in the medulla but none of the spinal YFP-immunoreactive neurons. These results show that brainstem PPG neurons innervate spinal autonomic and somatic motor neurons. The distributions of spinal PPG axons and spinal GLP-1 receptors correlate well. SPN receive the densest PPG innervation. Brainstem PPG neurons could directly modulate sympathetic outflow through their spinal inputs to SPN or interneurons

Differential sensitivity of brainstem vs cortical astrocytes to changes in pH reveals functional regional specialization of astroglia

Astrocytes might function as brain interoceptors capable of detecting different (chemo)sensory modalities and transmitting sensory information to the relevant neural networks controlling vital functions. For example, astrocytes which reside near the ventral surface of the brainstem (central respiratory chemosensitive area) respond to physiological decreases in pH with vigorous elevations in intracellular Ca(2+) and release of ATP. ATP transmits astroglial excitation to the brainstem respiratory network and contributes to adaptive changes in lung ventilation. Here we show that in terms of pH-sensitivity ventral brainstem astrocytes are clearly distinct from astrocytes residing in the cerebral cortex. We monitored vesicular fusion in cultured rat brainstem astrocytes using total internal reflection fluorescence microscopy and found that approximately 35% of them respond to acidification with an increased rate of exocytosis of ATP-containing vesicular compartments. These fusion events require intracellular Ca(2+) signaling and are independent of autocrine ATP actions. In contrast, the rate of vesicular fusion in cultured cortical astrocytes is not affected by changes in pH. Compared to cortical astrocytes, ventral brainstem astrocytes display higher levels of expression of genes encoding proteins associated with ATP vesicular transport and fusion, including vesicle-associated membrane protein-3 and vesicular nucleotide transporter. These results suggest that astrocytes residing in different parts of the rat brain are functionally specialized. In contrast to cortical astrocytes, astrocytes of the brainstem chemosensitive area(s) possess signaling properties which are functionally relevant – they are able to sense changes in pH and respond to acidification with enhanced vesicular release of ATP

Searching for stable fullerenes in space with computational chemistry

We report a computational study of the stability and infrared (IR) vibrational spectra of neutral and singly ionised fullerene cages containing between 44 and 70 carbon atoms. The stability is characterised in terms of the standard enthalpy of formation per CC bond, the HOMO-LUMO gap, and the energy required to eliminate a C$_2$ fragment. We compare the simulated IR spectra of these fullerene species to the observed emission spectra of several planetary nebulae (Tc 1, SMP SMC 16, and SMP LMC 56) where strong C$_{60}$ emission has been detected. Although we could not conclusively identify fullerenes other than C$_{60}$ and C$_{70}$, our results point to the possible presence of smaller (44, 50, and 56-atom) cages in those astronomical objects. Observational confirmation of our prediction should become possible when the James Webb Space Telescope comes online.Comment: 11 pages, 13 figures, 1 table. Accepted for publication on MNRA

Trends of the major porin gene (ompF) evolution

OmpF is one of the major general porins of Enterobacteriaceae that belongs to the first line of bacterial defense and interactions with the biotic as well as abiotic environments. Porins are surface exposed and their structures strongly reflect the history of multiple interactions with the environmental challenges. Unfortunately, little is known on diversity of porin genes of Enterobacteriaceae and the genus Yersinia especially. We analyzed the sequences of the ompF gene from 73 Yersinia strains covering 14 known species. The phylogenetic analysis placed most of the Yersinia strains in the same line assigned by 16S rDNA-gyrB tree. Very high congruence in the tree topologies was observed for Y. enterocolitica, Y. kristensenii, Y. ruckeri, indicating that intragenic recombination in these species had no effect on the ompF gene. A significant level of intra- and interspecies recombination was found for Y. aleksiciae, Y. intermedia and Y. mollaretii. Our analysis shows that the ompF gene of Yersinia has evolved with nonrandom mutational rate under purifying selection. However, several surface loops in the OmpF porin contain positively selected sites, which very likely reflect adaptive diversification Yersinia to their ecological niches. To our knowledge, this is a first investigation of diversity of the porin gene covering the whole genus of the family Enterobacteriaceae. This study demonstrates that recombination and positive selection both contribute to evolution of ompF, but the relative contribution of these evolutionary forces are different among Yersinia species