13 research outputs found
Assessment of splenic function
Hyposplenic patients are at risk of overwhelming post-splenectomy infection (OPSI), which carries mortality of up to 70%. Therefore, preventive measures are warranted. However, patients with diminished splenic function are difficult to identify. In this review we discuss immunological, haematological and scintigraphic parameters that can be used to measure splenic function. IgM memory B cells are a potential parameter for assessing splenic function; however, more studies are necessary for its validation. Detection of Howell–Jolly bodies does not reflect splenic function accurately, whereas determining the percentage of pitted erythrocytes is a well-evaluated method and seems a good first-line investigation for assessing splenic function. When assessing spleen function, 99mTc-labelled, heat-altered, autologous erythrocyte scintigraphy with multimodality single photon emission computed tomography (SPECT)-CT technology is the best approach, as all facets of splenic function are evaluated. In conclusion, although scintigraphic methods are most reliable, they are not suitable for screening large populations. We therefore recommend using the percentage of pitted erythrocytes, albeit suboptimal, as a first-line investigation and subsequently confirming abnormal readings by means of scintigraphy. More studies evaluating the value of potentially new markers are needed
Ecological commonalities among pelagic fishes: comparison of freshwater ciscoes and marine herring and sprat
Systematic comparisons of the ecology between functionally similar fish species from freshwater and marine aquatic systems are surprisingly rare. Here, we discuss commonalities and differences in evolutionary history, population genetics, reproduction and life history, ecological interactions, behavioural ecology and physiological ecology of temperate and Arctic freshwater coregonids (vendace and ciscoes, Coregonus spp.) and marine clupeids (herring, Clupea harengus, and sprat, Sprattus sprattus). We further elucidate potential effects of climate warming on these groups of fish based on the ecological features of coregonids and clupeids documented in the previous parts of the review. These freshwater and marine fishes share a surprisingly high number of similarities. Both groups are relatively short-lived, pelagic planktivorous fishes. The genetic differentiation of local populations is weak and seems to be in part correlated to an astonishing variability of spawning times. The discrete thermal window of each species influences habitat use, diel vertical migrations and supposedly also life history variations. Complex life cycles and preference for cool or cold water make all species vulnerable to the effects of global warming. It is suggested that future research on the functional interdependence between spawning time, life history characteristics, thermal windows and genetic differentiation may profit from a systematic comparison of the patterns found in either coregonids or clupeids
The Survival of Non-capitalism
This article explores the importance of non-capitalist space within the global political economy. The issue of how to categorise and understand space in so-called peripheral regions such as Latin America has been a contentious one. Whilst many radical analyses have focused on the dynamics of capitalism in relation to the geography of development, explaining how it has been able to survive and grow, this article makes the case for a more multi-linear theoretical framework with which to view the socio-economic landscape. This is inspired not only by the later writings of Marx but also the specific Marxian class analysis of those involved in Rethinking Marxism. Via a focus on Oaxaca in southern Mexico, this article highlights both the survival and the recreation of spaces of non-capitalism, and provides an argument for why we should consider these to be important for transformative action more broadly, whilst also discussing their potential limitations
Reflections on Local and Economy-Wide Effects of Territorial Competition
As part of the global trend towards greater reliance on market forces in public sector activities, there is a growing tendency in many countries to devolve the responsibility for regional development to regional and local authorities. From this perspective, vigorous competition between such authorities to attract productive enterprises, finance and households is expected to enhance the competitiveness of regions and to lead to higher local and national growth. Yet uncoordinated policies that do not take network and external spillover effects into account may be wasteful in the short run and lead to lower growth in the long run. This paper focuses on lessons from conventional and new theories of growth for understanding the impact of territorial competition. In addition, notions of regional competitiveness and their effectiveness as indicators of the regional growth potential are discussed. Although increasing competitiveness may induce higher growth, observed high growth rates are sometimes erroneously interpreted as evidence of competitiveness. Forces leading to convergence and divergence in an open regional system are identified and the impact of territorial competition is addressed. Specific attention is paid to regional incentives to encourage inward investment. While footloose firms appear responsive to such incentives, regional competition in the form of tax or non-tax incentives may bear little relationship with the spatial variation in unemployment rates or other indicators of regional economic problems. Incentives are therefore not always welfare enhancing. Some issues for further research are suggested
Nitrogen assimilation in Escherichia coli: putting molecular data into a systems perspective.
We present a comprehensive overview of the hierarchical network of intracellular processes revolving around central nitrogen metabolism in Escherichia coli. The hierarchy intertwines transport, metabolism, signaling leading to posttranslational modification, and transcription. The protein components of the network include an ammonium transporter (AmtB), a glutamine transporter (GlnHPQ), two ammonium assimilation pathways (glutamine synthetase [GS]-glutamate synthase [glutamine 2-oxoglutarate amidotransferase {GOGAT}] and glutamate dehydrogenase [GDH]), the two bifunctional enzymes adenylyl transferase/adenylyl-removing enzyme (ATase) and uridylyl transferase/uridylyl-removing enzyme (UTase), the two trimeric signal transduction proteins (GlnB and GlnK), the two-component regulatory system composed of the histidine protein kinase nitrogen regulator II (NRII) and the response nitrogen regulator I (NRI), three global transcriptional regulators called nitrogen assimilation control (Nac) protein, leucine-responsive regulatory protein (Lrp), and cyclic AMP (cAMP) receptor protein (Crp), the glutaminases, and the nitrogen-phosphotransferase system. First, the structural and molecular knowledge on these proteins is reviewed. Thereafter, the activities of the components as they engage together in transport, metabolism, signal transduction, and transcription and their regulation are discussed. Next, old and new molecular data and physiological data are put into a common perspective on integral cellular functioning, especially with the aim of resolving counterintuitive or paradoxical processes featured in nitrogen assimilation. Finally, we articulate what still remains to be discovered and what general lessons can be learned from the vast amounts of data that are available now