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Mild cognitive impairment (MCI) types may have distinct neuropathological substrates with hippocampal atrophy particularly common in amnestic MCI (aMCI). However, depending on the MCI classification criteria applied to the sample (e.g., number of abnormal test scores considered or thresholds for impairment), volumetric findings between MCI types may change. Additionally, despite increased clinical use, no prior research has examined volumetric differences in MCI types using the automated volumetric software, Neuroreader™.
Methods:
The present study separately applied the Petersen/Winblad and Jak/Bondi MCI criteria to a clinical sample of older adults (N = 82) who underwent neuropsychological testing and brain MRI. Volumetric data were analyzed using Neuroreader™ and hippocampal volumes were compared between aMCI and non-amnestic MCI (naMCI).
Results:
T-tests revealed that regardless of MCI classification criteria, hippocampal volume z-scores were significantly lower in aMCI compared to naMCI (p’s < .05), and hippocampal volume z-scores significantly differed from 0 (Neuroreader™ normative mean) in the aMCI group only (p’s < .05). Additionally, significant, positive correlations were found between measures of delayed recall and hippocampal z-scores in aMCI using either MCI classification criteria (p’s < .05).
Conclusions:
We provide evidence of correlated neuroanatomical changes associated with memory performance for two commonly used neuropsychological MCI classification criteria. Future research should investigate the clinical utility of hippocampal volumes analyzed via Neuroreader™ in MCI.
Non-typhoidal Salmonella (NTS) serovars, sequences types and antimicrobial susceptibility profiles have specific associations with animal and human infections in Vietnam. Antimicrobial resistance may have an effect on the manifestation of human NTS infections, with isolates from asymptomatic individuals being more susceptible to antimicrobials than those associated with animals and human diarrhoea.
This study examined the relationship between patient performance on multiple memory measures and regional brain volumes using an FDA-cleared quantitative volumetric analysis program – Neuroreader™.
Method:
Ninety-two patients diagnosed with mild cognitive impairment (MCI) by a clinical neuropsychologist completed cognitive evaluations and underwent MR Neuroreader™ within 1 year of testing. Select brain regions were correlated with three widely used memory tests. Regression analyses were conducted to determine if using more than one memory measures would better predict hippocampal z-scores and to explore the added value of recognition memory to prediction models.
Results:
Memory performances were most strongly correlated with hippocampal volumes than other brain regions. After controlling for encoding/Immediate Recall standard scores, statistically significant correlations emerged between Delayed Recall and hippocampal volumes (rs ranging from .348 to .490). Regression analysis revealed that evaluating memory performance across multiple memory measures is a better predictor of hippocampal volume than individual memory performances. Recognition memory did not add further predictive utility to regression analyses.
Conclusions:
This study provides support for use of MR Neuroreader™ hippocampal volumes as a clinically informative biomarker associated with memory performance, which is a critical diagnostic feature of MCI phenotype.
Around 80% of the world population of Northern Rockhopper Penguin Eudyptes moseleyi is found at Tristan da Cunha and Gough Island in the South Atlantic Ocean, where populations appear to be declining. However, numbers of birds at Middle Island, a small satellite island of Nightingale Island at Tristan Cunha, have not been counted since 1973 when an estimated 100,000 pairs were recorded. Updated population counts were obtained for all four islands at Tristan da Cunha (Tristan, Inaccessible, Nightingale and Middle islands) in 2009 providing a census of the whole island group and the first repeat count of Middle Island. Estimated breeding numbers at these four islands were Tristan 6,700 pairs, Inaccessible 54,000 pairs, Nightingale 25,000 pairs and 83,000 pairs at Middle Island. These counts confirm that Tristan da Cunha is a vitally important site for this ?Endangered? species holding over 65% of the global population and that breeding number have been relatively stable over the last 30 years.
More than 60% of newborns with severe congenital cardiac disease develop perioperative brain injuries. Known risk factors include: pre-operative hypoxemia, cardiopulmonary bypass characteristics, and post-operative hypotension. Infection is an established risk factor for white matter injury in premature newborns. In this study, we examined term infants with congenital cardiac disease requiring surgical repair to determine whether infection is associated with white matter injury. Acquired infection was specified by site – bloodstream, pneumonia, or surgical site infection – according to strict definitions. Infection was present in 23 of 127 infants. Pre- and post-operative imaging was evaluated for acquired injury by a paediatric neuroradiologist. Overall, there was no difference in newly acquired post-operative white matter injury in infants with infection (30%), compared to those without (31%). When stratified by anatomy, infants with transposition of the great arteries, and bloodstream infection had an estimated doubling of risk of white matter injury that was not significant, whereas those with single ventricle anatomy had no apparent added risk. When considering only infants without stroke, the estimated association was higher, and became significant after adjusting for duration of inotrope therapy. In this study, nosocomial infection was not associated with white matter injury. Nonetheless, when controlling for risk factors, there was an association between bloodstream infection and white matter injury in selected sub-populations. Infection prevention may have the potential to mitigate long-term neurologic impairment as a consequence of white matter injury, which underscores the importance of attention to infection control for these patients.
The cetacean fauna at the Tristan da Cunha archipelago has been assessed from ship-based, aerial and land-based observations from 1983–2000, from strandings on Tristan da Cunha and Inaccessible Island between 1983 and 1995, and from whaling catch data from 1934–1967. Five species (Eubalaena australis, Megaptera novaeangliae, Tasmacetus shepherdi, Globicephala melas and Orcinus orca) have been sighted within the territorial waters of the archipelago, eight species (Balaenoptera physalus, B. borealis, B. acutorostrata/bonaerensis, Physeter macrocephalus, Mesoplodon mirus, M. bowdoini, Delphinus sp. and Lissodelphis peronii) have been seen or taken within 200 nautical miles (360 km) of the group or have been found stranded on its shores, while another two species (Caperea marginata and Lagenorhynchus obscurus) have been recorded close enough to be considered likely to occur within 200 nautical miles. The records of Mesoplodon mirus and M. bowdoini represent significant extensions to their known distribution. Apart from its possible importance as a mid-oceanic nursery area for southern right whales, the waters of the Tristan Archipelago seem to be a concentration area for T. shepherdi, one of the least-known of the world's cetaceans.
Populations of the recently split Northern Rockhopper Penguin Eudyptes moseleyi are restricted to Tristan da Cunha and Gough Island in the South Atlantic, and Amsterdam and St Paul in the Indian Ocean. The majority of the population is in the Atlantic (> 80%), but population trends at Tristan da Cunha and Gough are uncertain. Early records indicate “millions” of penguins used to occur at Tristan da Cunha and Gough Island. The most recent estimates indicate declines in excess of 90% for both Gough and the main island of Tristan that have occurred over at least 45 and 130 years, respectively. Numbers breeding at Inaccessible and Nightingale islands (TDC) also may have declined since the 1970s, albeit modestly, whereas numbers on Tristan appear stable over the last few decades. Current population estimates are 32,000–65,000 pairs at Gough, 18–27,000 at Inaccessible, 19,500 at Nightingale, and 3,200–4,500 at Tristan. Numbers and trends at Middle Island (TDC) are unknown. Middle Island supported an estimated 100,000 pairs in 1973, and recent observations suggest this colony is being impacted by competition for space with recently recolonising Subantarctic Fur Seals Arctocephalus tropicalis. Past human exploitation and the impact of introduced predators may be responsible for the historical decline in numbers at Tristan, but these factors cannot explain the sharp decrease (since the 1950s) at Gough Island. Overall, declines at Gough, Tristan, Nightingale and Inaccessible islands indicate a three-generation decline of > 50%. Taken in combination with recent decreases in Indian Ocean populations, the Northern Rockhopper Penguins is now categorised as globally ‘Endangered’. Determining the causal factors responsible for these recent declines is an urgent priority.
cerebellar hypoplasia is a rare malformation caused by a variety of etiologies. it usually manifests clinically as non-progressive cerebellar ataxia with or without mental retardation. we further characterize a syndrome of autosomal recessive cerebellar hypoplasia in the hutterite population, referred to as dysequilibrium syndrome (des). we reviewed 12 patients (eight females, four males; age range 4 to 33y) with this syndrome. patients were examined and underwent a standard set of investigations to characterize better the clinical features, natural history, and neuroimaging of this syndrome. des is an autosomal recessive disorder with distinct clinical features including global developmental delay, late ambulation (after age 6y), truncal ataxia, and a static clinical course. neuroimaging is characterized by hypoplasia of the inferior portion of the cerebellar hemispheres and vermis, and mild simplification of cortical gyri.
The properties of nanocomposite tantalum carbide/amorphous hydrocarbon (TaC/a-C:H) thin films depend closely on reactive magnetron sputtering deposition process conditions. The chemical composition and structure trends for TaC/a-C:H films were obtained as a function of three deposition parameters: acetylene flow rate, applied direct current (dc) bias voltage, and substrate carousel rotation rate. Films were deposited according to a 23 factorial experimental design to enable multiple linear regression modeling of property trends. The Ta/C atomic ratio, hydrogen content, total film thickness, TaC crystallite size, and Raman spectra were statistically dependent on acetylene flow rate, applied dc bias voltage, or both. Transmission electron microscopy revealed a nanometer-scale lamellar film structure, the periodicity of which was affected mostly by substrate carousel rotation rate. The empirical property trends were interpreted with respect to hypothesized growth mechanisms that incorporate elements of physical vapor deposition and plasma-enhanced chemical vapor deposition.
The Hand of Compassion: Portraits of Moral Choice During the
Holocaust. By Kristin Renwick Monroe. Princeton: Princeton University
Press, 2004. 392p. $29.95.
Kristin Monroe interviews several non-Jewish rescuers during the
Holocaust to get at their moral psychology and motives in rescuing Jews
imperiled by the Nazis. Her extensive notes and transcripts provide an
intimate and powerful glance into how rescuers viewed their own actions
and how they discerned their own motives. For most “it just seemed
the right thing to do.” Monroe's Rousseauian argument is
intriguing both in the presentation of the narratives and in her careful,
systematic analysis of the moral psychology behind the rescuers'
action. She moves in a very different direction than, say, Frantz
Fanon's analysis in The Wretched of the Earth (1963) where
he sees the emotions of rage and revenge as central to the resistance of
the colonized. These two powerful emotions I found to be the primary
dynamic behind rescue in the narratives of Jewish resistors and rescuers
(Glass, Jewish Resistance During the Holocaust: Moral Uses of Violence
and Will, 2004). The gentile rescuers Monroe interviewed rarely spoke
of their anger or rage toward the Germans. Rather, the action of rescue
arose through an empathic connection with the victims, for example,
Margot: “You have either compassion with these people or you think
‘I couldn't care less when they drop dead’” (p.
20).
Tristan Albatross Diomedea [exulans] dabbenena is the most genetically distinct of the five taxa that form the Wan
dering Albatross superspecies, and has been listed as Endangered. It breeds only on Gough and Inaccessible Islands
in the Tristan da Cunha group, central South Atlantic Ocean. The entire breeding population was surveyed during
1999-2000. A mid-September survey at Gough Island recorded 1,129 chicks, equivalent to an annual breeding effort
by approximately 1,500 pairs. Only one chick was present at Inaccessible Island in 1999, and another pair laid an
egg in 2000. The annual breeding effort at this island has not exceeded three pairs since the 1950s. None were found
during an incomplete survey at Tristan, where the species bred in the past, but birds were seen flying over the island.
A complete survey and attempts to promote recolonization of Tristan are warranted. Breeding success at Gough Island
averaged 63%, and no birds that bred successfully attempted to breed the following year. Breeding success was
greater and less variable in a large colony at Gonydale than at a peripheral colony at Tafelkop. Young birds returned
to the island after 3-4 years (4-5 years old), and the modal age of first breeding was 8 years, with some individuals
breeding as young as 6 years. Most chicks (81%) recruited to their natal colony, but some recruited to colonies up to
3 km from their natal site. Among adults, fidelity to partners and breeding colony was high. Of nine birds recovered
away from the island, at least four were killed by longline fishing. Despite its known mortality on longlines, the Gough
Island census exceeded demipopulation estimates from the 1970s and early 1980s, possibly due to incomplete coverage
by previous surveys and a poor breeding season in 1998. Given the lack of evidence for a population decrease, Tristan
Albatross should be listed as Vulnerable. It is the third rarest albatross species, however, and its population size
warrants monitoring. We provide guidelines for repeatable censuses at Gough Island.
Silicon-incorporated amorphous hydrocarbon (Si-aC:H) films with varying Si contents were deposited onto a Ti interlayer on Si and steel substrates by reactive sputtering in an unbalanced magnetron sputtering system. The objective of this study was to measure and relate the structural, chemical, and mechanical properties of these Si-aC:H films. Transmission electron microscopy revealed that the Si-aC:H phase is amorphous and TiC exists at the Si-aC:H/Ti phase boundary for all compositions. Mechanical properties such as hardness, indentation modulus, and intrinsic stress decreased with increasing Si and H content in the films, for Si/C ≥ 0.04. XPS measurements suggested that this is most likely due to the decreasing presence of a C-C sp3 interlinked network, accompanied by an increase in C-H and Si-H bonds. This conclusion was supported by radial distribution functions obtained using extended electron energy-loss fine structure analysis (EXELFS).
Thermal spray of carbide coatings with high hardness and corrosion resistance onto steel substrates has technological importance. The adhesive strength is greatly effected by the interfacial impurities. Low porous and good quality 200 μm thick 86WC10Co4Cr coatings on 4140 steel are obtained by thermal spray methods using SC-HVOF gun at Cooper Oil Tools, Houston, TX. A Carl Zeiss DSM942 SEM with 3.5 nm resolution at 30 keV and Kevex LPX1 Super Dry Quantum Si(Li) Detector with < 145 eV resolution for Energy Dispersive X-ray Spectroscopy (EDXS) were used to study the elemental distribution across the interface. Fig. 1 shows the SEM micrographs of the interface between 86WC10Co4Cr thermal spray coating and 4140 steel substrate. The anchor patterns seen at the interface are believed to improve the adhesive qualities between the coating and the substrate.
Thermal spray processing has become an important powder-consolidation technique to yield new materials for extremes of temperature, radiation, wear, corrosion and mechanical stresses. High Velocity Oxy-Fuel (HVOF) spray coating process gives higher deposition densities and coating hardness; lower oxide content and porosity. The adhesive strength of thermal spray coatings is greatly effected by the interfacial impurities. The ring shear test method shown in Fig. 1 appears to give the most accurate results on shear adhesive strength. A typical ring shear test result of 88WC12Co 1/4" ring HVOF thermal spray coating on 4140 steel rod using a Jet kote thermal spray gun is shown in Fig. 2. Repeated ring shear tests on similar samples prepared under same spray and test conditions resulted in different shear bond strength and coating ring displacement before break off. We examined the ring shear tested coatings using a Zeiss DMS942 Scanning Electron Microscope (SEM) and Kevex Energy Dispersive X-ray Spectrometer (EDXS) with LPX1 Quantum Si(Li) Detector.
The CZT boule was grown by a modified vertical Bridgman process using in-situ compounding, Cd over-pressure and a pyrolytic boron nitride crucible within a fused ampoule. During growth, the Cd vapor pressure was near 1 atmosphere. These growth conditions tend to give high purity, good stoichiometry, few precipitates, and dislocation densities in the low to mid-104 cm−2 range. The crystals, after polishing, were annealed in a nearly saturated Cd, Zn atmosphere to fill residual Cd-site vacancies and achieve high resistivity in the 1010 γ-cm range. Low temperature photoluminescence study shows very good crystalline quality and a very low concentration of deep level recombinations. Single crystal samples were diced into 1 cm squares for evaluation as gamma ray detectors. The best detector results (4.5% resolution at 60 keV) were achieved for a 2 hour anneal at 850°C.