Ultrastructural and molecular characterisation of the neuronal nucleus.

Within the mammalian nucleus, many major cellular functions are performed including transcription, pre-mRNA splicing and ribosome assembly, all of which are important for successful gene expression, and, to achieve this, the nucleus has evolved as a highly organised, dynamic structure (Dundr and Misteli, 2001). In this study a complete ultrastructural and molecular investigation of the neuronal nucleus has been undertaken, characterising three subdomains in detail: speckles, the nucleolus, and the Cajal body. It has recently been established that several human neurodegenerative diseases are associated with changes in the organisation of the neuronal nucleus, and this is believed to be the principle cause of cellular dysfunction and resulting clinical symptoms. Many of these diseases and their associated nuclear pathology have successfully been reproduced in transgenic mouse models. In this study I have determined the detailed ultrastructural and molecular organisation of the nucleus of neurons within the striatum of the mouse brain and compared this to nuclei of striatal neurons in a transgenic mouse model of Huntington's disease and in a mutant mouse lacking the gene for the protein p80 coilin. In the HD mouse there is a dramatic reorganisation of the nucleus accompanied by the formation of a novel nuclear subdomain, the neuronal intranuclear inclusion (Nil), which is associated with the movement of the Cajal body from the nucleolus to the Nil. This occurs with a change in the molecular composition of the speckles and a major reorganisation in the structure of the nucleolus. In contrast, the p80 mutant mouse is characterised by major alterations in the distribution and molecular composition of the Cajal body. However, this is not similarly associated with dramatic changes in either the speckles or the nucleolus. These studies clearly establish novel and important changes in the organisation of the neuronal nucleus associated with the formation of the Nil in Huntington's disease

Baseline tests of the EPC Hummingbird electric passenger vehicle

The rear-mounted internal combustion engine in a four-passenger Volkswagen Thing was replaced with an electric motor made by modifying an aircraft generator and powered by 12 heavy-duty, lead-acid battery modules. Vehicle performance tests were conducted to measure vehicle maximum speed, range at constant speed, range over stop-and-go driving schedules, maximum acceleration, gradeability limit, road energy consumption, road power, indicated energy consumption, braking capability, battery charger efficiency, and battery characteristics. Test results are presented in tables and charts

Contamination of Boone-St. Joe Limestone Groundwater by Septic Tanks and Chicken Houses

Eighty-one water samples were collected from wells in the Boone-St. Joe limestone aquifer of northwest Arkansas and analyzed for fecal coliform, fecal streptococcus, total coliform bacteria, chloride, phosphate, nitrate and sulfate to determine the degree of contamination. Forty-nine percent of the samples had fecal streptococcus counts greater than 1 colony per 100 ml, 68% had total coliform counts of 1 or more colonies per 100 ml, and 9% of the wells had fecal coliform counts of 1 or more colonies per 100 ml. Water from wells in Clarksville, Nixa, Noark, Tonti and Waben cherty silt loam soils showed from 83 to 100% bacterial contamination. Nitrate concentrations exceeded 45 ppm in 80% of the wells in Waben soils and in 50% of wells in Nixa soils, with wells in the other soil types having nitrate concentrations of less than 45 ppm. Nitrate, sulfate, and chloride concentrations were all found to be statistically related. Wells closest to chicken houses were found to have statistically greater choloride concentrations. Chloride was also found to be statistically greater in wells with shallow casing. Wells within 150 meters of a photo-lineament were found to have greater fecal coliform contamination than wells farther away. The results indicate the ease at which wells can be contaminated with only shallow casing, in cherty soils, and/or near chicken houses or fractures (photo-lineaments

Prasinophyte bloom and putative fungi abundance near the Kačák event (Middle Devonian) from the Odivelas Limestone, Southwest Iberia

The Kačák Event is one of the several prominent Devonian climatic and biotic perturbations with a supra-regional to global extent. Its record can be traced in the litho- and biostratigraphy of uppermost Eifelian-lowermostGivetian strata and with multiple geochemical and geophysical proxies. In southwest Iberia, within southwestern Ossa-Morena Zone domains, there are rare, scattered Early-Middle Devonian limestone occurrences. One of these occurrences—the Odivelas Limestone type locality—is revisited in terms of conodont biostratigraphy and palynology and the results compared with previous data on reef macrofauna and magnetic susceptibility stratigraphy. The new data show that this locality is probably within the Polygnathus hemiansatus zone, i.e. of the earliest Givetian age. The palynological content of a ca. 2 m of black, organic-rich, fine grained limestone section is dominated, in varied proportions, by amorphous organic matter, putative fungal hyphae, and prasinophycean algae. The results are interpreted as an indication of high organic productivity and deposition in hypoxic to anoxic settings and probable biotic crisis, in both marine and terrestrial realms, connected with the Middle Devonian Kačák Event. The similarity of this record with other Devonian events is discussed

Long‐Term Responses Of The Kuparuk River Ecosystem To Phosphorus Fertilization

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117218/1/ecy2004854939.pd

Idiopatski i sekundarni stečeni megakolon kod pasa udruženi su sa smanjenom vip-inervacijom u oštećenom kolonu

It is well established that megacolon in carnivores, including both cats and dogs, is a common finding. Megacolon occurs more often in the cat that the dog. Based on current data idiopathic megacolon is a common cause of constipation in cats (62% of constipated cats are affected by diopathic megacolon). There is no evidence of idiopathic megacolon in dogs and publications about this disease in this species is very scarce. We investigated the enteric nervous system in the dilated portion (DP) of the colon in dogs with idiopathic aquired (n=7) or secondary aquired megacolon (n=21) and compared the results with a normal colon in control dogs (n=3). Colonic sections of surgical specimens were investigated by conventional and immunohistochemical methods, including pan-neuronal markers (NSE, synaptophisin, and neurofilament) and VIP, as well as S-100 protein for detection of ganglionic glial cells. Compared to controls, the two megacolon groups showed no changes of density of enteric neurons in both submucosal and myenteric nervous plexuses in DP of the colon and of enteric glial cells. However, compared to controls and dogs with secondary megacolon, there was a significant decrease in the density of NFP-ir nerve fibers in the longitudinal muscle layer in dogs with idiopathic acquired megacolon. In addition, dogs with idiopathic megacolon display decreased VIP-ir in the myenteric plexus and lamina propria mucosae, and absence of VIP-ir neurons in the submucosal plexus of DP of the colon. Similar alterations, although of lesser severity, may be found in dogs with secondary aquired megacolon. We consider that both idiopathic and secondary aquired megacolon might occur on the basis of a dysplastic changes of VIP-ir enteric neurons.Poznato je da se magakolon javlja kod mesojeda, uključujući mačke i pse, pri čemu je ovo oboljenje daleko učestalije kod mačaka. Na osnovu dosadašnjih saznanja, idiopatski megakolon je čest uzročnik konstipacije kod mačaka i 62% mačaka sa konstipacijom ima idiopatski megakolon. Istovremeno, podaci o psima sa idiopatskim megakolonom veoma su oskudni. U ovom radu je proučavan enterični nervni sistem u dilatiranom delu kolona kod 7 pasa sa idiopatskim megakolonom i 21 psa sa sekundarnim stečenim megakolonom, a rezultati su upoređeni sa normalnim kolonom kod 3 kontrolne zdrave životinje. Tkivni preseci kolona bojeni su klasičnim histološkim i imunohistohemijskim metodama, pri čemu su primenjeni pan-neuronski markeri (NSE, sinaptofizin i neurofilament) i VIP, kao i S-100 protein za detekciju glijalnih ćelija u enteričnim ganglijama. Nisu otkrivene razlike u gustini enteričnih neurona u submukoznom i mijenteričnom pleksusu kod životinja sa megakolonom, kao ni razlike u gustini glijalnih ćelija enteričnih ganglija, u odnosu na kontrolnu grupu životinja. Međutim, u odnosu na kontrolnu grupu, kod životinja sa idiopatskim megakolonom dokazana je smanjena VIP-imunoreaktivnost (ir) u mienteričnom pleksusu i krznu mukoze, kao i kompletno odsustvo VIP-ir neurona u submukoznom pleksusu dilatiranog dela kolona. Slične promene, ali u manjem stepenu, postojale su kod pasa sa sekundarnim stečenim megakolonom. Može da se zaključi da u patogenezi idiopatskog i sekundarnog stečenog megakolona značajnu ulogu imaju displastične promene u VIP-ergičkim neuronima enteričkog nervnog sistema

Increase in Tau Pathology in P290S Mapt Knock-In Mice Crossed with AppNL-G-F Mice

Alzheimer's Disease (AD) is characterized by the pathological assembly of Aβ peptide, which deposits into extracellular plaques, and tau, which accumulates in intraneuronal inclusions. To investigate the link between Aβ and tau pathologies, experimental models featuring both pathologies are needed. We developed a mouse model featuring both tau and Aβ pathologies by knocking the P290S mutation into murine Mapt and crossing these MaptP290S KI mice with the AppNL-G-F KI line. MaptP290S KI mice developed a small number of tau inclusions, which increased with age. The amount of tau pathology was significantly larger in AppNL-G-FxMaptP290S KI mice from 18-months of age onwards. Tau pathology was higher in limbic areas, including hippocampus, amygdala and piriform/entorhinal cortex. We also observed AT100-and Gallyas-Braak-silver-positive dystrophic neurites containing assembled filamentous tau, as visualized by in situ EM. Using a cell-based tau seeding assay, we showed that sarkosyl-insoluble brain extracts from both 18-month-old MaptP290S KI and AppNL-G-FxMaptP290S KI mice were seed-competent, with brain extracts from double KI mice seeding significantly more than those from the MaptP290S KI mice. Finally, we showed that AppNL-G-FxMaptP290S KI mice had neurodegeneration in the piriform cortex from 18-months of age. We suggest that AppNL-G-F x MaptP290S KI mice provide a good model for studying the interactions of aggregation-prone tau, Aβ, neuritic plaques, neurodegeneration and aging

Ecology, behaviour and management of the European catfish

The extreme body sizes of ‘megafishes’ associated with their high commercial values and recreational interests have made them highly threatened in their native range worldwide by human-induced impacts such as overexploitation. Meanwhile, and because of the aforementioned interests, some megafishes have been introduced outside of their native range. A notable exampled is the European catfish (Silurus glanis), one of the few siluriforms native from western Europe and among the 10 largest freshwater fish worldwide, attaining a total length over 2.7 m and a documented mass of 130 kg. Its distinct phylogeny and extreme size imply many features rare among other European fish such as peculiar behaviours (massive aggregations, beaching), consumption of large bodied prey, fast growth rate, long lifespan, high fecundity, nest guarding and large eggs. The spread of the species is likely to continue due to illegal introduction coupled with natural range extension due to current and future climate change. Based on these attributes and potential future risks, this introduced giant predator in European fresh waters could provide a novel model species of high utility for testing aspects of ecological and invasion theory and associated hypotheses. Here, we reviewed the most recent knowledge on the current distribution and the ecology of the species to understand how this can help advance our understanding of biological invasions. We also identified key research questions that should help stimulating new research on this intriguing, yet largely unknown, species and, more generally, on the ecology of invasive species

Multipoint-to-point data aggregation using a single receiver and frequency-multiplexed intensity-modulated ONUs

We demonstrate 2.5-GHz-spaced frequency multiplexing capable of aggregating 64 intensity-modulated end-users using low-speed electronic and optoelectronic components. All optical network units (ONUs) achieved high per-user capacity with dedicated optical bands, enabling future low latency applications