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Freezing of gait (FoG) in Parkinson’s disease (PD) has been associated with response inhibition. However, the relationship between response inhibition, neural dysfunction, and PD remains unclear. We assessed response inhibition and microstructural integrity of brain regions involved in response inhibition [right hemisphere inferior frontal cortex (IFC), bilateral pre-supplementary motor areas (preSMA), and subthalamic nuclei (STN)] in PD subjects with and without FoG and elderly controls.
Twenty-one people with PD and FoG (PD-FoG), 18 without FoG (PD-noFoG), and 19 age-matched controls (HC) completed a Stop-Signal Task (SST) and MRI scan. Probabilistic fiber tractography assessed structural integrity (fractional anisotropy, FA) among IFC, preSMA, and STN regions.
Stop-signal performance did not differ between PD and HC, nor between PD-FoG and PD-noFoG. Differences in white matter integrity were observed across groups (.001 < p < .064), but were restricted to PD versus HC groups; no differences in FA were observed between PD-FoG and PD-noFoG (p > .096). Interestingly, worse FoG was associated with higher (better) mean FA in the r-preSMA, (β = .547, p = .015). Microstructural integrity of the r-IFC, r-preSMA, and r-STN tracts correlated with stop-signal performance in HC (p ≤ .019), but not people with PD.
These results do not support inefficient response inhibition in PD-FoG. Those with PD exhibited white matter loss in the response inhibition network, but this was not associated with FoG, nor with response inhibition deficits, suggesting FoG-specific neural changes may occur outside the response inhibition network. As shown previously, white matter loss was associated with response inhibition in elderly controls, suggesting PD may disturb this relationship.
The foetal mammary gland is sensitive to maternal weight and nutrition during gestation, which could affect offspring milk production. It has previously been shown that ewes born to dams offered maintenance nutrition during pregnancy (day 21 to 140 of gestation) produced greater milk, lactose and CP yields in their first lactation when compared with ewes born to dams offered ad libitum nutrition. In addition, ewes born to heavier dams produced greater milk and lactose yields when compared with ewes born to lighter dams. The objective of this study was to analyse and compare the 5-year lactation performance of the previously mentioned ewes, born to heavy or light dams that were offered maintenance or ad libitum pregnancy nutrition. Ewes were milked once per week, for the first 6 weeks of their lactation, for 5 years. Using milk yield and composition data, accumulated yields were calculated over a 42-day period for each year for milk, milk fat, CP, true protein, casein and lactose using a Legendre orthogonal polynomial model. Over the 5-year period, ewes born to heavy dams produced greater average milk (P=0.04), lactose (P=0.01) and CP (P=0.04) yields than offspring born to light dams. In contrast, over the 5-year period dam nutrition during pregnancy did not affect average (P>0.05) offspring milk yields or composition, but did increase milk and lactose accumulated yield (P=0.03 and 0.01, respectively) in the first lactation. These results indicate that maternal gestational nutrition appears to only affect the first lactational performance of ewe offspring. Neither dam nutrition nor size affected grand-offspring live weight gain to, or live weight at weaning (P>0.05). Combined these data indicate that under the conditions of the present study, manipulating dam weight or nutrition in pregnancy can have some effects of offspring lactational performance, however, these effects are not large enough to alter grand-offspring growth to weaning. Therefore, such manipulations are not a viable management tool for farmers to influence lamb growth to weaning.
Experiments on the National Ignition Facility show that multi-dimensional effects currently dominate the implosion performance. Low mode implosion symmetry and hydrodynamic instabilities seeded by capsule mounting features appear to be two key limiting factors for implosion performance. One reason these factors have a large impact on the performance of inertial confinement fusion implosions is the high convergence required to achieve high fusion gains. To tackle these problems, a predictable implosion platform is needed meaning experiments must trade-off high gain for performance. LANL has adopted three main approaches to develop a one-dimensional (1D) implosion platform where 1D means measured yield over the 1D clean calculation. A high adiabat, low convergence platform is being developed using beryllium capsules enabling larger case-to-capsule ratios to improve symmetry. The second approach is liquid fuel layers using wetted foam targets. With liquid fuel layers, the implosion convergence can be controlled via the initial vapor pressure set by the target fielding temperature. The last method is double shell targets. For double shells, the smaller inner shell houses the DT fuel and the convergence of this cavity is relatively small compared to hot spot ignition. However, double shell targets have a different set of trade-off versus advantages. Details for each of these approaches are described.
Kochia is a troublesome weed throughout the western United States. Although
glyphosate effectively controls kochia, poor control was observed in several
no-till fields in Kansas. The objectives of this research were to evaluate
kochia populations response to glyphosate and examine the mechanism that
causes differential response to glyphosate. Glyphosate was applied at 0, 54,
109, 218, 435, 870, 1305, 1740, 3480, and 5220 g ae ha−1 on 10
kochia populations. In general, kochia populations differed in their
response to glyphosate. At 21 d after treatment, injury from glyphosate
applied at 870 g ha−1 range from 4 to 91%. In addition,
glyphosate rate required to cause 50% visible injury (GR50)
ranged from 470 to 2149 g ha−1. Differences in glyphosate
absorption and translocation and kochia mineral content were not sufficient
to explain differential kochia response to glyphosate.
Pyroxasulfone (KIH-485) is a seedling growth-inhibiting herbicide developed by Kumiai America that has the potential to control weeds in sunflower. However, little is known about how this herbicide will interact with various soil types and environments when combined with sulfentrazone. The objective of this research was to evaluate sunflower injury and weed control with pyroxasulfone applied with and without sulfentrazone across the Great Plains sunflower production area. A multisite study was initiated in spring 2007 to evaluate sunflower response to pyroxasulfone applied PRE at 0, 167, 208, or 333 g ai ha−1. In 2008, pyroxasulfone was applied alone and in tank mixture with sulfentrazone. In 2007, no sunflower injury was observed with any rate of pyroxasulfone at any location except Highmore, SD, where sunflower injury was 17%, 4 wk after treatment (WAT) with 333 g ha−1. In 2008, sunflower injury ranged from 0 to 4% for all treatments. Adding sulfentrazone did not increase injury. Sunflower yield was only reduced in treatments in which weeds were not effectively controlled. These treatments included the untreated control and pyroxasulfone at 167 g ha−1. Sunflower yield did not differ among the other treatments of pyroxasulfone or sulfentrazone applied alone or in combination. The addition of sulfentrazone to pyroxasulfone improved control of foxtail barley, prostrate pigweed, wild buckwheat, Palmer amaranth, and marshelder, but not large crabgrass or green foxtail. The combination of pyroxasulfone and sulfentrazone did not reduce control of any of the weeds evaluated.
We examined the relationships between exclusive breast-feeding and the risks of respiratory, diarrhoea and nutritional morbidities during the first 2 years of life among children born to women infected with HIV-1.
We prospectively determined the incidence of respiratory illnesses, diarrhoea, fever, hospitalizations, outpatient visits and nutritional morbidities. Generalized estimating equations were used to estimate the relative risks for morbidity episodes and Cox proportional hazards models to estimate the incidence rate ratios of nutritional morbidities.
Dar es Salaam, Tanzania.
The sample consisted of 666 children born to HIV-infected women.
The 666 children were followed for 2 years. Exclusive breast-feeding was associated with lower risk for cough (rate ratio (RR) = 0·49, 95 % CI 0·41, 0·60, P < 0·0001), cough and fever (RR = 0·44, 95 % CI 0·32, 0·60, P < 0·0001) and cough and difficulty breathing or refusal to feed (RR = 0·31, 95 % CI 0·18, 0·55, P < 0·0001). Exclusive breast-feeding was also associated with lower risk of acute diarrhoea, watery diarrhoea, dysentery, fever and outpatient visits during the first 6 months of life, but showed no effect at 6–24 months of life. Exclusive breast-feeding did not significantly reduce the risks of nutritional morbidities during the first 2 years of life.
Exclusive breast-feeding is strongly associated with reductions in the risk of respiratory and diarrhoea morbidities during the first 6 months of life among children born to HIV-infected women.
The current study investigated the effects of dam weight and nutrition during gestation on the reproductive performance of female primiparous offspring at 2 years of age. Four hundred and fifty heavy (H) (mean±s.e.m.: 60·8 kg±0·18) and 450 light (L) (42·5 kg±0·17) dams were randomly allocated to ad libitum (A) or maintenance (M) nutritional regimens from day 21 until day 140 of pregnancy, under pastoral grazing conditions. One week prior to lambing, all dams and their lambs were provided with ad libitum feeding through to weaning. After weaning, female progeny were managed and fed to requirements as one group. At 2 years of age, the oestrous cycles of the female offspring (n=207) were synchronized and the offspring were naturally mated. Ewes were scanned for pregnancy by ultrasound at day 70 of pregnancy. Within 24 h of birth, lambs were weighed and body dimensions were measured. Lambs were also weighed at day 24 (L24) and weaning. No effects of dam nutrition or dam weight were found (P>0·10) on the reproductive performance of the ewe offspring. Lambs of M-grand-dams were heavier at birth (P=0·024) and weaning (P=0·031) than lambs of A-grand-dams. Twin lambs of H-grand-dams were heavier at birth (P=0·014) than twin lambs of L-grand-dams; however, grand-dam weight had no effect (P>0·10) on lamb weaning weight. In summary, dam weight had no effect on reproductive performance of the female offspring, with only a minor effect on the weight of grand-offspring. Thus, being born to a larger dam has no advantages over being born to a smaller dam, in terms of number of lambs born and weight of lambs at birth and weaning. Grand-dam maintenance nutrition had no effect on reproductive performance although it increased lamb birth and weaning weight and lamb growth rates of the grand-offspring. Therefore, this indicates that ewes born to dams fed at maintenance during pregnancy have an advantage over A-ewes in physiological stressful situations including pregnancy or lactation.
It was hypothesized that exposure of the fetus to adverse conditions in utero due to either maternal constraint or nutrition may result in developmental adaptations altering metabolism and postnatal growth of the offspring. Heavy (H) and light (L) Romney dams (G0) were allocated to ad libitum (A) or maintenance (M) nutritional regimens, from day 21–day 140 of pregnancy. Female twin-born offspring (G1) born to the dams in the four treatment groups will be referred to as HA-ewes, LA-ewes, HM-ewes and LM-ewes. At 16 months of age, offspring were catheterized and given intravenous insulin tolerance test (ITT), glucose tolerance test (GTT) and epinephrine tolerance test challenges to assess their glucose and fat metabolism in relation to their birth weight and postnatal growth. In HA-ewes, the regression coefficients of growth rates prior to puberty on insulin and glucose curves in response to GTT (InsAUCGTT) and ITT (GluAUCITT), respectively, were different from 0 (P < 0.05) and were different from the regression coefficients of HM-ewes. This may indicate that HA-ewes may have showed puberty-related insulin resistance at 16 months of age with increasing growth rates prior to puberty compared to HM- or LM-ewes. In HM-ewes, the regression coefficients of growth rates after puberty on InsAUCGTT and GluAUCITT were different from 0 (P < 0.05) and were different from those of HA-ewes. These results may indicate that offspring born to heavy dams fed maintenance during pregnancy and with greater postnatal growth rates after puberty could develop glucose intolerance and insulin resistance in later life.
Objective: Despite the prevalence of homelessness, this population has rarely been included in disaster and terrorism planning. To better understand the mental health needs of the homeless during a terrorist event and to highlight the need to address methodological limitations in research in this area, we examined responses to the October 2002 Washington, DC, sniper attacks.
Methods: We interviewed 151 homeless individuals 1 year after the Washington, DC, sniper attacks.
Results: The majority (92.7%) was aware of the sniper events; 84.1% stayed informed through the media and 72.7% had someone to turn to for emotional support. Almost half (44%) reported identification with victims and 41% increased substance use during the attacks. More than half (61.7%) felt extremely frightened or terrified and 57.6% reported high perceived threat. Females, nonwhites, and participants with less than a high school education experienced greater threat. Women, nonwhites, and younger (<43 years old) participants were more likely to have decreased more activities and 32.7% increased confidence in local law enforcement; however, 32.7% became less confident.
Conclusions: During a terrorist attack the homeless population may be difficult to reach or reluctant to comply with public health programs. Addressing barriers to health care in vulnerable groups is critical to effective public health disaster response. (Disaster Med Public Health Preparedness. 2009;3:163–167)
Reverberation mapping takes advantage of the presence of a time delay or lag, τ, between continuum and emission line flux variations observed through spectroscopic monitoring campaigns to infer the radius of the broad-line region (BLR) and, subsequently, the central black hole mass in type 1 AGNs. We present results from a multi-month reverberation mapping campaign undertaken primarily at MDM Observatory with supporting observations from around the world. We measure BLR radii and black hole masses for six objects. The primary goal of this campaign was to obtain either new or improved Hβ reverberation lag measurements for several relatively low-luminosity AGNs. Using cross correlation techniques to measure the time delay between the mean optical continuum flux density around 5100 Å and the integrated Hβ flux, we determine the Hβ lags and black hole mass measurements listed in columns 2 and 3 of Table 1, respectively. Column 4 tells if this measurement is new, an improvement meant to replace a previous, less reliable measurement, or simply an additional measurement not used to replace a previous value. The complete results from this study are currently being prepared for publication. A subsequent velocity-resolved analysis of the Hβ response shows that three of the six primary targets demonstrate kinematic signatures (column 5) of infall, outflow, and non-radial virialized motions (see Denney et al. 2009).
Two correlative approaches to the challenge of ecological niche modeling (genetic algorithm, maximum entropy) were used to estimate the potential global distribution of the invasive fruit fly, Bactrocera invadens, based on associations between known occurrence records and a set of environmental predictor variables. The two models yielded similar estimates, largely corresponding to Equatorial climate classes with high levels of precipitation. The maximum entropy approach was somewhat more conservative in its evaluation of suitability, depending on thresholds for presence/absence that are selected, largely excluding areas with distinct dry seasons; the genetic algorithm models, in contrast, indicate that climate class as partly suitable. Predictive tests based on independent distributional data indicate that model predictions are quite robust. Field observations in Benin and Tanzania confirm relationships between seasonal occurrences of this species and humidity and temperature.
J. P. Singh, Diagnostics Instrumentation and Analysis Laboratory (DIAL), Mississippi State University, USA,
F. Y. Yueh, Diagnostics Instrumentation and Analysis Laboratory (DIAL), Mississippi State University, USA,
V. N. Rai, Diagnostics Instrumentation and Analysis Laboratory (DIAL), Mississippi State University, USA,
R. Harmon, US Army Research Laboratory, Research Triangle Park, USA,
S. Beaton, ADA Technologies, Inc., USA,
P. French, ADA Technologies, Inc., USA,
F. C. DeLucia, US Army Research Laboratory, Aberdeen Proving Ground, USA,
B. Peterson, US Army Research Laboratory, Aberdeen Proving Ground, USA,
K. L. McNesby, US Army Research Laboratory, Aberdeen Proving Ground, USA,
A. W. Miziolek, US Army Research Laboratory, Aberdeen Proving Ground, USA
Laser-induced breakdown spectroscopy (LIBS) has demonstrated its capability in quantitative determination of elemental composition in various samples in laboratories for decades. Recently, the interest in applying LIBS to detect various hazardous materials in the environment has grown rapidly. This chapter reviews some recent work related to environmental contamination studies using LIBS. Two portable LIBS instruments developed for field application are described in this chapter. The first instrument has been used by the US Army Research Laboratory to analyze the contaminated soil from Army sites and also for other geological applications. The other system was used by Mississippi State University to detect the resources conservation and recovery act (RCRA) metals in the off-gas of industrial plants and in liquids. The practical problems with LIBS application in environmental application such as calibration and sensitivity are also discussed in this chapter. The concept of using a new generation of broadband spectrometers to improve LIBS' capability in monitoring multiple emission lines of the same element to improve the detection limit and other signal enhancement techniques is addressed. The initial result of LIBS application in environmental problems is encouraging. We believe that the performance of LIBS in environmental application will continuously improve with the commercial development of various components in LIBS detection system.
LIBS is a chemical sensor technology with a capability for real-time in situ analysis that was first demonstrated in the laboratory over two decades ago and is now at the threshold of widespread commercialization.
The evolution of a short injection-hole jet issuing into a crossflow at low blowing ratios is presented. Particle image velocimetry (PIV) is used to determine structural features of the jet/crossflow interaction throughout its development from within the jet supply channel (which feeds the holes), through the injection hole, and into the crossflow. The effect of supply channel feed orientations, i.e. counter to, or in the same direction as the crossflow is emphasized. Feed orientation profoundly affects such jet characteristics as trajectory and lateral spreading, as well as its structural features. Fluid within the high-speed supply channel exhibits swirling motions similar to the flow induced by a pair of counter-rotating vortices. The sense of rotation of the swirling fluid depends upon the orientation of the supply channel flow with respect to the crossflow, and in turn impacts the in-hole velocity fields. In the coflow supply channel geometry (channel flow is in the same direction as the free stream), a pair of vortices exists within the hole with the same sense of rotation as the primary jet counter-rotating vortex pair (CRVP). In contrast, the counterflow supply channel configuration has in-hole vortices of opposite rotational sense to that of the CRVP. The in-hole vortices interact constructively or destructively with the CRVP, thus affecting the strength and coherence of the CRVP. The counterflow configuration has a weakened CRVP because of destructive interference with the in-hole vortices. The weaker CRVP has a lower trajectory and increased spanwise spreading. External to the injection hole, a pair of vortices exists immediately downstream of the jet. They are initially perpendicular to the boundary-layer plate near the wall and are outboard of the streamwise hole centreline. These vortices, denoted ‘downstream spiral separation node’ (DSSN) vortices, are affected by both the supply channel feed direction and the blowing ratio. They appear to form by free-stream fluid wrapping around the jet and interacting with the CRVP. The coflow supply channel geometry is associated with the largest and most well-defined DSSN vortices, and their size is inversely proportional to the blowing ratio. At low blowing ratio, these vortices induce a large recirculating flow region downstream of the injection hole at the wall.
We present the preliminary results of a frequency analysis of 1457 fundamental mode RR Lyrae (RR0) stars in the Large Magellanic Cloud (LMC) from MACHO Project photometry. We find the same classes of pulsational behavior as were found in our earlier survey of first overtone RR Lyrae (RR1) stars. Variables whose prewhitened power spectra contain one or two peaks close to the main frequency component in the original power spectra are commonly known as Blazhko-type variables. The present analysis shows the overall frequency of Blazhko-type stars in the total RR0 population analysed to date to be ≈ 10%. This is lower than the often cited Galactic field/globular rate of 20-30% (Szeidl, 1988).
The incidence rate of Blazhko-type variability in the LMC appears to be about three times higher in RR0 stars than in RR1 stars. This puts important constraints on possible models of the Blazhko effect.
An epidemiological and microbiological investigation of a cluster of eight cases of
Legionnaires' disease in Los Angeles County in November 1997 yielded conflicting results. The
epidemiological part of the investigation implicated one of several mobile cooling towers used
by a film studio in the centre of the outbreak area. However, water sampled from these cooling
towers contained L. pneumophila serogroup 1 of another subtype than the strain that was
recovered from case-patients in the outbreak. Samples from two cooling towers located
downwind from all of the case-patients contained a Legionella strain that was indistinguishable
from the outbreak strain by four subtyping techniques (AP-PCR, PFGE, MAb, and MLEE). It
is unlikely that these cooling towers were the source of infection for all the case-patients, and
they were not associated with risk of disease in the case-control study. The outbreak strain also
was not distinguishable, by three subtyping techniques (AP-PCR, PFGE, and MAb), from a
L. pneumophila strain that had caused an outbreak in Providence, RI, in 1993. Laboratory
cross-contamination was unlikely because the initial subtyping was done in different
In this investigation, microbiology was helpful for distinguishing the outbreak cluster from
unrelated cases of Legionnaires' disease occurring elsewhere. However, multiple subtyping
techniques failed to distinguish environmental sources that were probably not associated with
the outbreak. Persons investigating Legionnaires' disease outbreaks should be aware that
microbiological subtyping does not always identify a source with absolute certainty.