Endogenous Processes in European Regional Growth: Convergence and Policy

The traditional empirical approaches to the analysis of economic growth,cross‐section and panel data regressions are substantially uninformative withrespect to the issue of convergence. Whether national or regional economies appear to converge in terms of per capita income or productivity levels (the so‐called β‐convergence) critically depends on the way in which the empirical model is specified. Traditional specifications witness a disproportionate presence of proxies for forces leading towards divergence among the conditioning variables. It is therefore hardly surprising that these analyses find a positive and statistically significant value for the estimate of the speed of convergence. A more constructive use of cross‐section and panel data regressions is in the analysis of the determinants of growth. The present paper therefore builds on recent work on the role of different growth determinants (Cheshire and Carbonaro 1996) and analyses the growth performance of 122 Functional Urban Regions (FURs)over the period 1978–1994. This model explicitly recognizes growth as amultivariate process. In this new formulation it incorporates a spatialized adaptation of Romer's endogenous growth model (Romer 1990), developing the work of Magrini (Magrini 1997). Magrini's model originated from the view that technological knowledge has a very important tacit component that has been neglected in formal theories of endogenous growth. This tacit component, being the non‐written personal heritage of individuals or groups, is naturally concentrated in space. As a result, technological change is profoundly influenced by the interaction between firms and their local environments. The present paper reports the results of the estimation of a fully specified model of regional growth in per capita income. Particular attention is played to the role of research and development (R&D) activities, and to the influence of factors such as Universities that shape the local environments and have important policy implications. These results are then applied to quantifying the scope for policy to influence the growth process. Several simulations are presented deriving alternative growth outcomes across European regions that would have been obtained if those variables over which policy might have control—including the contribution of human capital—had had alternative values reflecting the realistic scope of policy makers' influence. The implications for convergence/divergence in regional per capita income levels are then analyzed using a Markov chain approach (Quah 1993 and 1996; Magrini 1999).     

Gonadotropin-releasing hormone (GnRH) neuronal systems in the pejerrey, Odontesthes bonariensis (Atheriniformes)

The brain of the pejerrey (Odontesthes bonariensis) has recently been shown to contain three forms of gonadotropin-releasing hormone (GnRH): salmon GnRH (sGnRH), chicken GnRH-II (cGnRH-II) and pejerrey GnRH (pjGnRH), nevertheless neuroanatomical studies on the distribution of these peptides are lacking. In this study we investigated the distribution of immunoreactive GnRH in the brain of adult pejerrey. Four different policlonal antisera and a monoclonal antibody against different GnRH variants were applied on cryosections and visualized using the ABC method. Three antisera (PBL#49, sGnRH#2 and cII741) revealed three different immunoreactive areas: the terminal nerve ganglion (at the junction between the olfactory bulbs and the anterior telencephalon), the preoptic area just anterior to the hypothalamus and the midbrain tegmentum. Fibers immunoreactive to GnRH were detected in different brain areas: the olfactory bulbs, the ventral thelencephalon, the hypothalamus, the mesencephalic area and an important innervation entering into the pituitary gland. Two other antibodies (LRH13 and s1668) labeled the two nuclei corresponding to the forebrain but not the midbrain tegmentum. As both antibodies have low crossreactivity to cGnRH-II, the data suggest that this group of cells express cGnRH-II. In summary, three different areas with immunoreactivity to GnRH were detected in the pejerrey brain. The distribution of sGnRH, pjGnRH and cGnRH-II expressing neurons, is discussed.     

Comparison of loss on ignition and thermal analysis stepwise methods for determination of sedimentary organic matter

• 1. Loss on ignition (LOI) is a widely used method to estimate organic matter (OM) in the sediment of marine and freshwater ecosystems. Thermogravimetric‐differential thermal analysis (TG‐DTA) of organic species provides information on thermal reactions, the amount and properties of clay structural water, organic species and carbonates.
• 2. The accuracy of LOI compared with that of TG‐DTA was evaluated in 33 sediment samples from the Lagoon of Venice (Italy).
• 3. In all tests conducted with TG‐DTA the mass loss of OM and the loss of clay structural water (LCSW) from oxidized samples were measured. The mass loss of OM at 350°C (TG‐DTA 350 OM) and the total extraction of organic matter at 567°C (TEOM) calculated from the difference between natural state samples and oxidized samples highlight the presence of both thermally labile and thermally stable substances.
• 4. The grain size data of sediment samples from the Lagoon shows a variable distribution between slightly muddy sand and mud. Loss of clay structural water at 350°C (LCSW 350) and total extraction of clay structural water at 567°C (TECSW) both estimated by TG‐DTA on oxidized samples, were found to correspond approximately to 6% and 10%, respectively of the clay fraction (<4 µm). This percentage may be used to correct LOI measurements of OM in sediments with high clay content.
• 5. LOI 350 (loss on ignition at 350°C) and LOI 550 (loss on ignition at 550°C) proved to be ～80% and ～200%, respectively, of total extraction of mass loss at 350°C (TG‐DTA 350 tot) and at 567°C (TEML) estimated by TG‐DTA on natural samples, meaning that the LOI 550 value represents a significant overestimate. The difference between the LOI 550 and TEML values indicates that the mass loss excess (MLE) may be accounted for by losses due to breakdown of carbonates.

Copyright © 2008 John Wiley & Sons, Ltd.     

A surplus production model with latent truncation and species targeting,with an application to Papua New Guinean fisheries

This paper first reviews traditional bio-economic models of catch–effort equilibrium and later contributions based on augmented and revised specifications. To overcome some of the pitfalls in fisheries analysis, an approach is formulated which accounts for latent truncation in the fishing fleet, species targeting and non-linear long-term relationships among catch, effort and biomass. The procedure is applied to purse seine and longline offshore marine fisheries in Papua New Guinea, where tuna and other fish resources are believed to be under-exploited on the whole, but selective overfishing is reported to take place. Statistical evidence of incidental truncation is weak, with results being sensitive to the selection of variables. Based on regression diagnostics and expected signs/statistical significance of parameter estimates, non-linear surplus production specifications prove to be more suited than original and unrestricted versions of the conventional approach for modelling the dominant (purse seine) fishery in PNG over the period 1979–2007, with both main and secondary target fishing being found not to exceed the maximum sustainable yield. In either case, policy implications of these results should be pondered against underreporting of official fish catches.     

Standardization of canine meningioma grading: Validation of new guidelines for reproducible histopathologic criteria

Canine meningiomas are currently graded using the human grading system. Recently published guidelines have adapted the human grading system for use in dogs. The goal of this study was to validate the new guidelines for canine meningiomas. To evaluate the inter-observer agreement, 5 veterinary surgical pathologists graded 158 canine meningiomas following the human grading system alone or with the new guidelines. The inter-observer agreement for histologic grade and each of the grading criteria (mitotic grade, invasion, spontaneous necrosis, macronucleoli, small cells, hypercellularity, pattern loss and anaplasia) was evaluated using the Fleiss kappa index. The diagnostic accuracy (sensitivity and specificity) was assessed by comparing the diagnoses obtained with the 2 grading systems with a consensus grade (considered the reference classification). The consensus histologic grade was obtained by agreement between 4 experienced veterinary neuropathologists following the guidelines. Compared with the human grading alone, the canine-specific guidelines increased the inter-observer agreement for: histologic grade (κ = 0.52); invasion (κ = 0.67); necrosis (κ = 0.62); small cells (κ = 0.36); pattern loss (κ = 0.49) and anaplasia (κ = 0.55). Mitotic grade agreement remained substantial (κ = 0.63). The guidelines improved the sensitivity in identifying grade 1 (95.6%) and the specificity in identifying grade 2 (96.2%) meningiomas. In conclusion, the new grading guidelines for canine meningiomas are associated with an overall improvement in the inter-observer agreement and higher diagnostic accuracy in diagnosing grade 1 and grade 2 meningiomas.