Beyond Ground Truth: GIS and the Environmental Knowledge of Herders, Professional Foresters, and Other Traditional Communities

As a result of increasingly apparent and problematic effects of global information system and remote sensing technologies, there has been increased emphasis on demonstrating and incorporating indigenous environmental knowledges in land use and cover analysis. Such approaches, though ethnographically revealing and politically efficacious, tend to reproduce a model of difference between local and scientific knowledges that is epistemologically untenable. This paper demonstrates an alternative use of geographic information system and remotely sensed imagery to both demonstrate the partiality of mapping technology and show possibilities for critical usage of the tool. Using a case from India, the research shows a method to elicit and explore competing environmental knowledges, including and especially those of scientific experts. The analysis concludes that, for both local producers and expert managers, the cultural meaning of landscapes is dependent on their roles in regional production and resource politics.     

P2X2 purine receptor immunoreactivity of intraganglionic laminar endings in the mouse gastrointestinal tract

The distribution of P2X(2) purine receptor subunit immunoreactivity has been investigated in the mouse gastrointestinal tract. Immunoreactivity occurred in intraganglionic laminar endings (IGLEs) associated with myenteric ganglia throughout the gastrointestinal tract. In the esophagus, IGLEs supplied every myenteric ganglion. The proportion of ganglia supplied decreased from 85% in the stomach to 10% in the ileum, and from 50% in the caecum to 15% in the distal colon. There was substantial loss of IGLEs from myenteric ganglia of all abdominal regions after bilateral subdiaphragmatic section of the vagus nerves. IGLEs in the esophagus consisted of dense clusters of punctate immunoreactive varicosities. In the stomach and duodenum they had prominent lamellar processes and irregular, but smaller, lamellae were found in other regions. Rare immunoreactive IGLEs occurred in the submucosa of the distal colon. P2X(2) receptor immunoreactivity was on the surfaces and in the cytoplasm of a minority of nerve cells in myenteric ganglia. It is concluded that P2X(2) purine receptor immunoreactivity is a feature of IGLEs in the mouse, and that P2X receptor agonists may modulate sensitivity of the IGLEs.     

Effects of soluble TNF receptor treatment on lipopolysaccharide-induced myocardial cytokine expression

Tumor necrosis factor (TNF)-alpha plays a key role in the pathogenesis of septic shock syndrome, and myocardial TNF-alpha expression may contribute to this pathophysiology. We examined the myocardial expression of TNF-alpha-related cytokines and chemokines in mice exposed to lipopolysaccharide (LPS) and tested the effects of anti-TNF therapy on myocardial cytokine expression. Cytokine mRNA levels were measured by RNase protection assay, and protein levels in the plasma and myocardium were assessed by enzyme-linked immunosorbent assays. LPS (4 microg/g body wt ip) induced marked cytokine expression, including TNF-alpha, interleukin (IL)-1beta, IL-6, and monocyte chemotactic protein (MCP)-1, in both the plasma and myocardium. Pretreatment with adenovirus-mediated TNF receptor fusion protein (AdTNFR1; 10(9) plaque-forming units iv) decreased plasma cytokine levels. In contrast, whereas myocardial IL-1beta expression was also suppressed, expression of IL-6 and MCP-1 was not inhibited by AdTNFR1. In summary, anti-TNF treatment differentially altered the cytokine expression in the plasma and myocardium during endotoxemia. Inability to block myocardial expression of IL-6 and MCP-1 suggests a possible mechanism for the failure of anti-TNF therapies in the treatment of endotoxin shock.     

Ephrin-A5 modulates cell adhesion and morphology in an integrin-dependent manner

The ephrins are membrane-tethered ligands for the Eph receptor tyrosine kinases, which play important roles in patterning of the nervous and vascular systems. It is now clear that ephrins are more than just ligands and can also act as signalling-competent receptors, participating in bidirectional signalling. We have recently shown that ephrin-A5 signals within caveola-like domains of the plasma membrane upon engagement with its cognate Eph receptor, leading to increased adhesion of the cells to fibronectin. Here we show that ephrin-A5 controls sequential biological events that are consistent with its role in neuronal guidance. Activation of ephrin-A5 induces an initial change in cell adhesion followed by changes in cell morphology. Both effects are dependent on the activation of beta1 integrin involving members of the Src family of protein tyrosine kinases. The prolonged activation of ERK-1 and ERK-2 is required for the change in cell morphology. Our work suggests a new role for class A ephrins in specifying the affinity of the cells towards various extracellular substrates by regulating integrin function.     

The oxidative DNA lesion 8,5'-(S)-cyclo-2'-deoxyadenosine is repaired by the nucleotide excision repair pathway and blocks gene expression in mammalian cells

Xeroderma pigmentosum (XP) patients with inherited defects in nucleotide excision repair (NER) are unable to excise from their DNA bulky photoproducts induced by UV radiation and therefore develop accelerated actinic damage, including cancer, on sun-exposed tissue. Some XP patients also develop a characteristic neurodegeneration believed to result from their inability to repair neuronal DNA damaged by endogenous metabolites since the harmful UV radiation in sunlight does not reach neurons. Free radicals, which are abundant in neurons, induce DNA lesions that, if unrepaired, might cause the XP neurodegeneration. Searching for such a lesion, we developed a synthesis for 8,5'-(S)-cyclo-2'-deoxyadenosine (cyclo-dA), a free radical-induced bulky lesion, and incorporated it into DNA to test its repair in mammalian cell extracts and living cells. Using extracts of normal and mutant Chinese hamster ovary (CHO) cells to test for NER and adult rat brain extracts to test for base excision repair, we found that cyclo-dA is repaired by NER and not by base excision repair. We measured host cell reactivation, which reflects a cell's capacity for NER, by transfecting CHO and XP cells with DNA constructs containing a single cyclo-dA or a cyclobutane thymine dimer at a specific site on the transcribed strand of a luciferase reporter gene. We found that, like the cyclobutane thymine dimer, cyclo-dA is a strong block to gene expression in CHO and human cells. Cyclo-dA was repaired extremely poorly in NER-deficient CHO cells and in cells from patients in XP complementation group A with neurodegeneration. Based on these findings, we propose that cyclo-dA is a candidate for an endogenous DNA lesion that might contribute to neurodegeneration in XP.     

Do-it-yourself statistics: A computer-assisted likelihood approach to analysis of data from genetic crosses

Graduate school programs in genetics have become so full that courses in statistics have often been eliminated. In addition, typical introductory statistics courses for the "statistics user" rather than the nascent statistician are laden with methods for analysis of measured variables while genetic data are most often discrete numbers. These courses are often seen by students and genetics professors alike as largely irrelevant cookbook courses. The powerful methods of likelihood analysis, although commonly employed in human genetics, are much less often used in other areas of genetics, even though current computational tools make this approach readily accessible. This article introduces the MLIKELY.PAS computer program and the logic of do-it-yourself maximum-likelihood statistics. The program itself, course materials, and expanded discussions of some examples that are only summarized here are available at http://www.unisi. it/ricerca/dip/bio_evol/sitomlikely/mlikely.h tml.     

Growth of Paenibacillus larvae,the causative agent of American foulbrood in honey bees and Bacillus popilliae,the causative agent of milky disease in beetle larvae in lepidopteran cell cultures

TNM-FH Lepidopteran insect cell culture medium containing 10% fetal bovine serum (FBS), while allowing limited vegetative growth of Paenibacillus larvae (wild-type strain), the causative agent of American foulbrood, contained no viable vegetative cells upon subculture, nor were any heat resistant spores produced in this medium alone. However, TNM-FH medium cotaining embryonic or midgut cells from Trichoplusia ni, hemocytes from Estigmene acrea, ovarian and embryonic cells from Spodoptera frugiperda, embryonic cells from Plutella xylostella, Spodoptera exigua and Pseudaletia unipuncta or ovarian cells from Lymantria dispar, supported both heavy vegetative cell growth and moderate production of heat resistant spores. EX-CELL 405 serum-free insect cell culture medium alone appeared to contain the appropriate nutrients required for both vegetative growth and sporulation of P. larvae. However, in the presence of embryonic cells from T. ni, limited vegetative growth occurred and the P. larvae cells appeared to die off. This was confirmed by the fact that no colony growth occurred upon subculture, nor were any heat resistant spores detected. This was true also in the presence of fat body cells from T. ni, except that a limited number of spores (4,000/ml) were detected in the form of cology-forming units (CFU) on plates following heating to 80°C for 20 minutes. In a parallel study with a wild-type strain of Bacillus popilliae, vegetative cells grew only in TNM-FH medium in the presence of mid-gut BTI-Tn-MG and ovarian (Tn-368) cells of T. ni. No heat resistant spores, however, were detected in any of the cultures. When BTI-Tn-MG and Tn-368 cells were further challenged with four variant cultures of B. popilliae, vegetative growth and limited sporulation were achieved. The BTI-Tn-MG cell line in TNM-FH medium produced as many as 12,000 spores/ml after 21 days in culture.