Randomized controlled trial assessing participation and quality of life in a supported speed treadmill training exercise program vs. a strengthening program for children with cerebral palsy.

OBJECTIVE: A multi-site Randomized-Controlled Trial compared a home-based Supported Speed Treadmill Training Exercise Program (SSTTEP) with a strengthening exercise program in children with cerebral palsy (CP) on the following categories; Participation, quality of life (QOL), self-concept, goal attainment, and satisfaction. DESIGN: Twenty-six children with spastic cerebral palsy were assigned by site-based block randomization to the SSTTEP (n=14) or strengthening exercise (n=12) group. Both groups participated in a two week clinic-based induction period and continued the intervention at home for ten weeks. Data were collected at baseline, post-intervention (12 weeks), and follow-up (16 weeks). Assessments included the Canadian Occupational Performance Measure, Children's Assessment of Participation and Enjoyment Scale, Pediatric Quality of Life Cerebral Palsy Module, and Piers-Harris Children's Self-Concept Scale. Evaluators were blinded to group assignment at two sites. RESULTS: Satisfaction and performance on individual goals, participation, and parent-reported QOL improved in both groups with improvement maintained for four weeks post intervention. CONCLUSION: The hypothesis that the SSTTEP group would have better outcomes than the exercise group was not supported. However, both groups showed that children with CP can make gains in participation, individual goals, and satisfaction following a 12-week intensive exercise intervention, and these findings persisted for four weeks post intervention.

Comparative analysis of distribution and abundance of West Nile and eastern equine encephalomyelitis virus vectors in Suffolk County, New York, using human population density and land use/cover data.

Five years of CDC light trap data from Suffolk County, NY, were analyzed to compare the applicability of human population density (HPD) and land use/cover (LUC) classification systems to describe mosquito abundance and to determine whether certain mosquito species of medical importance tend to be more common in urban (defined by HPD) or residential (defined by LUC) areas. Eleven study sites were categorized as urban or rural using U.S. Census Bureau data and by LUC types using geographic information systems (GISs). Abundance and percent composition of nine mosquito taxa, all known or potential vectors of arboviruses, were analyzed to determine spatial patterns. By HPD definitions, three mosquito species, Aedes canadensis (Theobald), Coquillettidia perturbans (Walker), and Culiseta melanura (Coquillett), differed significantly between habitat types, with higher abundance and percent composition in rural areas. Abundance and percent composition of these three species also increased with freshwater wetland, natural vegetation areas, or a combination when using LUC definitions. Additionally, two species, Ae. canadensis and Cs. melanura, were negatively affected by increased residential area. One species, Aedes vexans (Meigen), had higher percent composition in urban areas. Two medically important taxa, Culex spp. and Aedes triseriatus (Say), were proportionally more prevalent in residential areas by LUC classification, as was Aedes trivittatus (Coquillett). Although HPD classification was readily available and had some predictive value, LUC classification resulted in higher spatial resolution and better ability to develop location specific predictive models.

Chemical and enzymatic synthesis of 4'-thio-beta-D-arabinofuranosylcytosine monophosphate and triphosphate.

N4-Acetyl-1-(2, 3-di-O-acetyl-4-thio-beta-D-arabinofuranosyl) cytosine (2) was synthesized in three steps from 1-(4-thio-beta-D-arabinofuranosyl) cytosine (1). The reaction of this partially blocked 4'-thio-ara-C derivative 2 with 2-chloro-4H-1,3,2-benzodioxaphosphorin-4-one gave the 5-phosphitylate derivative 3, which on reaction with pyrophosphate gave the 5'-nucleosidylcyclotriphosphite 4. Product 4 was then oxidized with iodine/pyridine/water and deblocked with concentrated ammonium hydroxide to provide the desired 4'-thio-ara-C-5'-triphosphate 5. This triphosphate 5 was converted to 4'-thio-ara-C -5'-monophosphate 6 by treatment with snake venom phosphodiesterase I. The details of the synthesis, purification, and characterization of both nucleotides are described.

Synchronization rates in classes of relaxation oscillators.

Relaxation oscillators arise frequently in physics, electronics, mathematics, and biology. Their mathematical definitions possess a high degree of flexibility in the sense that through appropriate parameter choices relaxation oscillators can be made to exhibit qualitatively different kinds of oscillations. We study numerically four different classes of relaxation oscillators through their synchronization rates in one-dimensional chains with a Heaviside step function interaction and obtain the following results. Relaxation oscillators in the sinusoidal and relaxation regime both exhibit an average time to synchrony, approximately n, where n is the chain length. Relaxation oscillators in the singular limit exhibit approximately n(p), where p is a numerically obtained value less than 0.5. Relaxation oscillators in the singular limit with parameters modified so that they resemble spike oscillations exhibit approximately log(n) in chains and approximately log(L) in two-dimensional square networks of length L. Finally, using a sigmoid interaction results in approximately n(2), for relaxation oscillators in the sinusoidal and relaxation regimes, indicating that the form of the coupling is a controlling factor in the synchronization rate.

Synchronization in relaxation oscillator networks with conduction delays.

We study locally coupled networks of relaxation oscillators with excitatory connections and conduction delays and propose a mechanism for achieving zero phase-lag synchrony. Our mechanism is based on the observation that different rates of motion along different nullclines of the system can lead to synchrony in the presence of conduction delays. We analyze the system of two coupled oscillators and derive phase compression rates. This analysis indicates how to choose nullclines for individual relaxation oscillators in order to induce rapid synchrony. The numerical simulations demonstrate that our analytical results extend to locally coupled networks with conduction delays and that these networks can attain rapid synchrony with appropriately chosen nullclines and initial conditions. The robustness of the proposed mechanism is verified with respect to different nullclines, variations in parameter values, and initial conditions.

Synchrony and desynchrony in integrate-and-fire oscillators.

Due to many experimental reports of synchronous neural activity in the brain, there is much interest in understanding synchronization in networks of neural oscillators and its potential for computing perceptual organization. Contrary to Hopfield and Herz (1995), we find that networks of locally coupled integrate-and-fire oscillators can quickly synchronize. Furthermore, we examine the time needed to synchronize such networks. We observe that these networks synchronize at times proportional to the logarithm of their size, and we give the parameters used to control the rate of synchronization. Inspired by locally excitatory globally inhibitory oscillator network (LEGION) dynamics with relaxation oscillators (Terman & Wang, 1995), we find that global inhibition can play a similar role of desynchronization in a network of integrate-and-fire oscillators. We illustrate that a LEGION architecture with integrate-and-fire oscillators can be similarly used to address image analysis.

Aedes (Finlaya) japonicus japonicus (Theobald), a new introduction into the United States.

Aedes (Finlaya) japonicus japonicus is recorded for the 1st time in the United States. Four adult females were collected in light traps at 2 sites in New York and one site in New Jersey during the months of August and September 1998. Notes on bionomics are provided. Illustrations of the adult female, male, and larva are included.

Landscape patterns of abundance of Ixodes scapularis (Acari: Ixodidae) on Shelter Island, New York.

Nymphal Ixodes scapularis Say, the vector of Lyme borreliosis, was most common in forested areas across Shelter Island, Suffolk County, New York, and least common in xeric habitats such as beach and grassland. At the scale of individual house yards, nymphs were most common at wooded edges of property and least common on lawns. The abundance of ticks at yard edges was positively correlated with numbers on lawns and in landscaping, suggesting that tick abundance in woods affects abundances in adjacent yards. Because 57% of all yard area is adjacent to woodlands on Shelter Island, public health efforts to reduce tick populations in wooded areas should supplement efforts by individual yard owners to decrease risk. Methods of tick control for woodlands should also be evaluated for their effect on tick populations in adjacent yard habitats.

Ixodes scapularis (Acari: Ixodidae) deer tick mesoscale populations in natural areas: effects of deer, area, and location.

Nymphal Ixodes scapularis Say deer ticks were collected at 22 parks or other natural areas on Long Island, New York, to examine the relationship between tick populations and geographic position, size of area, presence of white-tailed deer, Odocoileus virginianus (Zimmerman), and numbers of human Lyme disease cases in adjacent communities. Nymphal ticks were 93% less abundant when deer were absent and were also less common in smaller natural areas. Geographic position on Long Island was not important. Tick numbers were significantly correlated with human Lyme disease incidence in adjacent townships. A second survey of larval ticks from five areas where deer were absent and six where deer were present found larvae present at four of the five sites without deer, but at only 2% of the levels found where deer were present. These results suggest that populations of I. scapularis can occur and reproduce in the absence of white-tailed deer, so that eradication of all deer would greatly reduce, but not eliminate, all risk of Lyme disease.

Ambient air temperature as a predictor of activity of adult Ixodes scapularis (Acari: Ixodidae).

Based on winter flagging experiments on Long Island, NY, adult Ixodes scapularis Say have an apparent threshold of questing activity at 4 degrees C. This threshold should be incorporated into public education efforts because the public may be at risk of contracting Lyme disease any time during the winter when temperatures exceed 4 degrees C.

An unexpected result from burning vegetation to reduce Lyme disease transmission risks.

The risk for human infection with Lyme disease appears linked to the abundance of infected vector ticks, principally Ixodes dammini Spielman, Clifford, Piesman & Corwin, in the eastern United States. Habitat destruction by burning, although not well studied, has long been considered as an effective alternative to synthetic insecticides as a means of reducing tick populations. We evaluated the effect of a single spring burning of the woodland understory on the transmission risk of Lyme disease spirochetes (Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner) on Shelter Island, Long Island, NY. Following a burn in early April 1991, the abundance of nymphal I. dammini was 49% lower in the burned portion of a woodlot compared with the unburned portion. However, risk of encountering nymphs infected with B. burgdorferi remained similar in both burned and unburned woods. It is suggested that burning vegetation may disproportionately kill deer-derived rather than rodent-derived nymphs, significantly reducing tick abundance without affecting transmission risk.

Unique phylogenetic position of Diplomonadida based on the complete small subunit ribosomal RNA sequence of Giardia ardeae, G. muris, G. duodenalis and Hexamita sp.

Complete small-subunit rRNA (SSU-rRNA) coding region sequences were determined for two species of the intestinal parasite Giardia: G. ardeae and G. muris, both belonging to the order Diplomonadida, and a free-living member of this order, Hexamita sp. These sequences were compared to published SSU-rDNA sequences from a third member of the genus Giardia, G. duodenalis (often called G. intestinalis or G. lamblia) and various representative organisms from other taxa. Of the three Giardia sequences analyzed, the SSU-rRNA from G. muris is the smallest (1432 bases as compared to 1435 and 1453 for G. ardeae and G. duodenalis, respectively) and has the lowest G+C content (58.9%). The Hexamita SSU-rRNA is the largest in this group, containing 1550 bases. Because the sizes of the SSU-rRNA are prokaryotic rather than typically eukaryotic, the secondary structures of the SSU-rRNAs were constructed. These structures show a number of typically eukaryotic signature sequences. Sequence alignments based on constraints imposed by secondary structure were used for construction of a phylogenetic tree for these four taxa. The results show that of the four diplomonads represented, the Giardia species form a distinct group. The other diplomonad Hexamita and the microsporidium Vairimorpha necatrix appear to be distinct from Giardia.

The nucleotide sequence of the entire ribosomal DNA operon and the structure of the large subunit rRNA of Giardia muris.

The total nucleotide sequence of the rDNA of Giardia muris, an intestinal protozoan parasite of rodents, has been determined. The repeat unit is 7668 basepairs (bp) in size and consists of a spacer of 3314 bp, a small-subunit rRNA (SSU-rRNA) gene of 1429, and a large-subunit rRNA (LSU-rRNA) gene of 2698 bp. The spacer contains long direct repeats and is heterogeneous in size. The LSU-rRNA of G. muris was compared to that of the human intestinal parasite Giardia duodenalis, to the bird parasite Giardia ardeae, and to that of Escherichia coli. The LSU-rRNA has a size comparable to the 23S rRNA of E. coli but shows structural features typical for eukaryotes. Some variable regions are typically small and account for the overall smaller size of this rRNA. The structure of the G. muris LSU-rRNA is similar to that of the other Giardia rRNA, but each rRNA has characteristic features residing in a number of variable regions.

Cloning and restriction enzyme mapping of ribosomal DNA of Giardia duodenalis, Giardia ardeae and Giardia muris.

In an attempt to study Giardia at the DNA sequence level, the rRNA genes of three species, Giardia duodenalis, Giardia ardeae and Giardia muris were cloned and restriction enzyme maps were constructed. The rDNA repeats of these Giardia show completely different restriction enzyme recognition patterns. The size of the rDNA repeat ranges from approximately 5.6 kb in G. duodenalis to 7.6 kb in both G. muris and G. ardeae. These size differences are mainly attributable to the variation in length of the spacer. Minor differences exist among these Giardia in the sizes of their small subunit rRNA and the internal transcribed spacer between small and large subunit rRNA. The genetic maps were constructed by sequence analysis of the DNA around the 5' and 3' ends of the mature rRNA genes and between the rRNA covering the 5.8S rRNA gene and internal transcribed spacer. Comparison of the 5.8S rDNA and 3' end of large subunit rDNA from these three Giardia species showed considerable sequence variation, but the rDNA sequences of G. duodenalis and G. ardeae appear more closely related to each other than to G. muris.

Phosphor-based thermometry of the rotor in a high-power electrical generator.

A prototype on-line rotor temperature monitor based on phosphor decay-time measurements using optical fibers was tested on two large electrical generators.

Giardia sp.: comparison of electrophoretic karyotypes.

Species in the genus Giardia have been named on the basis of host specificity, cell dimensions, and median body morphology. Despite these criteria, the species taxonomy of Giardia is still in question. To investigate Giardia taxonomy on a molecular level, Giardia chromosomal DNA was analyzed by orthogonal-field-alternation gel electrophoresis (OFAGE) and transverse alternating field electrophoresis (TAFE). Chromosomal DNA of G. duodenalis isolates (human, muskrat, sheep, dog, beaver), G. muris (mouse), and G. ardeae (great blue heron) were subjected to OFAGE and TAFE analyses. Comparable DNA patterns were obtained by both electrophoretic methods, but OFAGE required 8 days while TAFE required only 3 days. DNA patterns among all G. duodenalis isolates, although quite similar to each other, were distinctly different from those of G. muris and G. ardeae; G. muris and G. ardeae DNA patterns were distinctly different from each other. A G. duodenalis (Portland 1) total DNA probe hybridized to the DNA of all G. duodenalis isolates on Southern blots, but not detectably to G. muris and G. ardeae DNA. Similarly, G. muris and G. ardeae total DNA probes only hybridized detectably to their respective DNA. One probe that appears to hybridize to the DNA of all G. duodenalis and to G. ardeae DNA rather than G. muris DNA has been developed. Another probe that hybridizes only to G. muris and G. ardeae DNA has been developed. These data suggest that the differentiation of Giardia isolated from host and environmental samples may eventually be accomplished by DNA probes. Additionally, these techniques perhaps combined with other criteria may lead to the establishment of a sound taxonomic scheme for this genus.

Axenic culture and characterization of Giardia ardeae from the great blue heron (Ardea herodias).

Trophozoites of Giardia ardeae were obtained from the great blue heron (Ardea herodias) and established in axenic culture using the TYI-S-33 medium. The generation time in culture for G. ardeae was 22-25 hr, which was 3-fold longer than for Giardia duodenalis (WB strain). A morphological comparison of trophozoites in the original intestinal isolate to those grown in culture revealed that they were identical for the following characteristics: a pyriform-shaped body, a ventral adhesive disc with a deep notch in the posterior border, teardrop-shaped nuclei, pleomorphism in median body structure ranging from a round-oval appearance (Giardia muris type) to that of a clawhammer (G. duodenalis type), and a single caudal flagellum on the right side (as viewed dorsally) with the left one being rudimentary. Analysis of the chromosomal migration patterns was performed by orthogonal-field-alternation gel electrophoresis and demonstrated that the pattern for G. ardeae was distinctly different from that for G. duodenalis (Portland 1-CCW strain). Bacterial symbionts were seen attached to trophozoites in the original isolate but could not be detected in cultured trophozoites using scanning electron microscopy, fluorescence light microscopy using the Hoechst 33258 dye for DNA localization, or by standard microbiological techniques using nonselective media for growing aerobic or anaerobic bacteria. This study demonstrated that avian-derived Giardia could be grown in axenic culture; based on morphological criteria and chromosomal migration patterns, that G. ardeae should be considered a distinct species; and that rationale for determining Giardia spp., based on median body structure alone, should no longer be considered adequate for classification at the species level.

Aberrant guanosine triphosphate-beta-tubulin interaction in Alzheimer's disease.

Guanosine triphosphate (GTP) is an absolute requirement for tubulin polymerization in situ. The nucleotide photoaffinity probe 8-azidoguanosine 5'-triphosphate (8N3GTP) has been shown to be a biological mimic of GTP in this system and, also, an effective active site probe of the exchangeable GTP binding site. Using [32P]8N3GTP we demonstrate that the exchangeable GTP site of the beta subunit of tubulin is available to added guanine nucleotide in normal aged brain homogenates, whereas it is variably unavailable in Alzheimer's diseased brain. Inability of 8N3GTP to photolabel beta tubulin appears to be associated with neurofibrillary tangle density. These results support the hypothesis that microtubule formation is abnormal in brains affected by Alzheimer's disease.

Aluminum intoxication and the victim of Alzheimer's disease: similarities and differences.

Aluminum (Al) has been implicated in the pathogenesis and may produce a model of senile dementia of the Alzheimer's type (SDAT). To better understand the effects of Al on the mammalian brain, Al was studied in rabbits and rats using several experimental approaches. Similar behavioral toxicity and site and degree of neurofibrillary tangle (NFT) development were obtained after intracerebroventricular (icv) or repeated sc Al, although a more protracted time course after the latter. SDAT victims demonstrate some similar behavioral signs but a different type of NFT. A classically conditioned, defensive reflex (nictitating membrane extension) was used to compare response acquisition, retention, and extinction in Al-exposed and control rabbits of various ages. Both increasing age and Al exposure attenuated these measures, suggesting that advanced age and Al intoxication provide behavioral models of SDAT. A deficit in acquisition of a classically conditioned response (eyeblink) in senile-demented patients has been reported. These cognitive deficits in rabbits occurred after a less than two-fold increase in brain Al. Brain Al in SDAT victims has been reported to be unchanged or slightly increased. Further similarity to SDAT was obtained with 4-aminopyridine (4-AP) which attenuated Al-induced behavioral deficits in rabbits and the Al inhibition of glutamate release from rat hippocampal slices. 4-Aminopyridine has been reported to attenuate behavioral deficits in SDAT patients. A tubulin, GTP binding site was blocked in SDAT victim brain but not in control or Al-intoxicated rabbit brain, indicating a biochemical dissimilarity. In summary, Al-intoxication produces a model of SDAT with many similarities but significant differences.

Phosphor-based thermometry of rotating surfaces.

The use of phosphor thermometry in generator rotor temperature monitoring over the 60-150 degrees C range has been investigated, using measurements of the decay time of the visible emission stimulated in europiumdoped yttrium oxysulfide by UV laser excitation. A fiber-optic system for light delivery and collection has been designed and tested in laboratory measurements on a rotating disk. Measurements of the effect of oil and magnetic field on sensor performance are reported.