Longitudinal stability of temperamental exuberance and social–emotional outcomes in early childhood.

The goals of the current study were to investigate the stability of temperamental exuberance across infancy and toddlerhood and to examine the associations between exuberance and social–emotional outcomes in early childhood. The sample consisted of 291 4-month-olds followed at 9, 24, and 36 months and again at 5 years of age. Behavioral measures of exuberance were collected at 9, 24, and 36 months. At 36 months, frontal electroencephalogram (EEG) asymmetry was assessed. At 5 years, maternal reports of temperament and behavior problems were collected, as were observational measures of social behavior during an interaction with an unfamiliar peer in the laboratory. Latent profile analysis revealed a high, stable exuberance profile that was associated with greater ratings of 5-year externalizing behavior and surgency, as well as observed disruptive behavior and social competence with unfamiliar peers. These associations were particularly true for children who displayed left frontal EEG asymmetry. Multiple factors supported an approach bias for exuberant temperament but did not differentiate between adaptive and maladaptive social–emotional outcomes at 5 years of age. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Relationship between NP GCL Internal and HDPE GMX/NP GCL Interface Shear Strengths

An investigation was conducted on the relationship between the internal shear strength of hydrated needle-punched (NP) geosynthetic clay liners (GCLs) and the interface shear strength between hydrated NP GCLs (nonwoven side) and high-density polyethylene (HDPE) textured geomembranes (GMXs). New large-scale direct shear data are presented and compared to previous results obtained using similar materials and procedures. The data indicate that both GCLs and GMX/GCL interfaces display large postpeak strength reduction, even at high normal stress. Peak and large-displacement failure envelopes are nonlinear; except for the GCL internal residual strength envelope, which passes through the origin and has a friction angle of 4.8°. GMX/GCL interfaces can be expected to have lower peak strengths and higher large-displacement strengths than GCL internal shear specimens. However, the failure mode for GMX/GCL specimens can change from interface shear to GCL internal shear as normal stress increases. Design for peak strength conditions should be based on the lowest peak strength interface in a liner system, and design for large displacement conditions should be on the basis of the residual strength of the same interface.     

Punch-through protection of SSDs in beam accidents

We have tested the effectiveness of punch-through protection (PTP) structures on n-on-p AC-coupled Silicon strip detectors using pulses from an 1064 nm IR laser, which simulate beam accidents. The voltages on the strips are measured as a function of the bias voltage and compared with the results of DC I-V measurements, which are commonly used to characterize the PTP structures. We find that the PTP structures are only effective at very large currents (several mA), and clamp the strips to much larger voltages than assumed from the DC measurements. We also find that the finite resistance of the strip implant compromises the effectiveness of the PTP structures.     

Circumferential Catastrophic Burst Failures of Pressurized Cylinders

Complete circumferential (360°) tearing has been observed at the bottom of body walls in a number of three-piece, steel, cylindrical aerosol containers. This type of failure has not been well documented and analyzed in previous aerosol can failure analysis literature. In one instance, a worker accidentally dropped an aerosol spray paint can, and it instantly burst via catastrophic 360° circumferential failure near the bottom of the body wall. This was a relatively low-pressure, low-temperature, nearly instantaneous fracture. The burst aerosol became a high-velocity rocket and impacted the worker in the face and caused the loss of one eye. Other similar incidents involving this same failure mechanism have occurred with varying degrees of injury. The objective of this study was to determine why the aerosols catastrophically burst in the 360° circumferential manner and, more importantly, to find a remedy and prevent future failures. Test methods were developed to quantitatively control the force and angle of impact that might result from the tapping, hitting, or accidental dropping of an aerosol container. More common failure analysis methods were also used, such as metallography, scanning electron microscopy, energy dispersive spectroscopy, simple bending tests to simulate low-cycle fatigue, and a method to measure internal aerosol pressure as a function of temperature. The most likely root cause for the 360° burst failures was determined to be a combination of pre-existing circumferential flaw or flaws, the anisotropic microstructure of the aerosol body steel and above yield stress that is facilitated by the geometry of the body-to-bottom design when the aerosol is tapped, hit, or accidentally dropped. Experiments show that changing microstructure and/or design significantly reduce the likelihood of this failure mechanism and offer simple, cost-effective remedies.     

Precision and sensitivity of a test for vegetable fat adulteration of milk fat

A test for routine screening of Mozzarella cheese and butter for vegetable fat adulteration is described. Fat is extracted and saponified. The potassium salts of the fatty acids are measured through direct gas chromatographic analysis. A ratio, calculated from the concentrations of butyric and oleic acids, is used to evaluate the purity of a sample. The test offers good precision and can detect less than 10% partially hydrogenated vegetable fat.     

Mechanisms for the formation of low temperature,non-alloyed Au-Ge ohmic contacts to n-GaAs

Low temperature, non-alloyed Au-Ge contact formation ton-GaAs is a multi-step pro-cess. During the first 5 min of annealing at 320° C the Au and Ge segregate into regions a few microns in size and extend over the entire thickness of the metal layer and sig-nificant in-diffusion of the Au and Ge and out-diffusion of the Ga and As occurs. This intermixing reduces the barrier height from 0.75 to 0.40 eV. The contact does not show ohmic behavior until it has been annealed for 3 hr. During this time Ge continues to in-diffuse but at a slower rate than it did initially. The rate of Ge in-diffusion is en-hanced by the presence of Au since samples containing less Au require longer anneals to show ohmic behavior and have higher specific contact resistances. The presence of excess As, which is prevented from evaporating by a Si₃N₄ cap has the opposite effect since capped layers have higher specific contact resistances. Au-Ge phases appear after approximately 3 hr of annealing, therefore, Au-Ge phases cannot be responsible for the reduction in barrier height. The interface morphology is smooth, differing from that of pure Au and alloyed contacts that often contain spiking of the metals into the semi-conductor. The orientation relationship for the Au grains differs from that of pure Au. Work performedat U.S. Army ETDL, Fort Monmouth, NJ 07703. Work performed at U.S.Army ETDL, Fort Monmouth, NJ 07703.     

LGMD 2E in Tunisia is caused by a homozygous missense mutation in beta-sarcoglycan exon 3

Four of the currently recognized autosomal recessive limb-girdle muscular dystrophies (LGMD type 2C-F) are caused by mutations in the genes encoding components of the sarcoglycan complex. LGMD 2C, caused by mutations in gamma-sarcoglycan, is prevalent in northern Africa, especially in Tunisia, where this type of muscular dystrophy was originally described. Although the disease initially was assumed to be genetically homogeneous in this region, linkage to the alpha-sarcoglycan locus (LGMD 2D) has also been found. We have now identified the first Tunisian family with beta-sarcoglycanopathy (LGMD 2E), further adding to the genetic heterogeneity of autosomal recessive LGMD in this population. Direct sequencing of the beta-sarcoglycan gene revealed a homozygous mutation (G272-->T, Arg91Leu) in exon 3. This change affects the same arginine residue in the immediate extracellular domain of the protein that was mutated to a proline (G272-->C, Arg91Pro) in a Brazilian family with a severe form of the disease. Immunohistochemical analysis for the sarcoglycan complex demonstrates absence of the known components of the complex in both of these families. We postulate that the immediate extracellular domain of beta-sarcoglycan may be important for the assembly and/or maintenance of this complex, potentially mediated by disulfide-bond formation to another sarcoglycan via the single cysteine residue in that domain.     

Antisense oligonucleotide inhibition of hepatitis C virus gene expression in transformed hepatocytes

Genetic and biochemical studies have provided convincing evidence that the 5' noncoding region (5' NCR) of hepatitis C virus (HCV) is highly conserved among viral isolates worldwide and that translation of HCV is directed by an internal ribosome entry site (IRES) located within the 5' NCR. We have investigated inhibition of HCV gene expression using antisense oligonucleotides complementary to the 5' NCR, translation initiation codon, and core protein coding sequences. Oligonucleotides were evaluated for activity after treatment of a human hepatocyte cell line expressing the HCV 5' NCR, core protein coding sequences, and the majority of the envelope gene (E1). More than 50 oligonucleotides were evaluated for inhibition of HCV RNA and protein expression. Two oligonucleotides, ISIS 6095, targeted to a stem-loop structure within the 5' NCR known to be important for IRES function, and ISIS 6547, targeted to sequences spanning the AUG used for initiation of HCV polyprotein translation, were found to be the most effective at inhibiting HCV gene expression. ISIS 6095 and 6547 caused concentration-dependent reductions in HCV RNA and protein levels, with 50% inhibitory concentrations of 0.1 to 0.2 microM. Reduction of RNA levels, and subsequently protein levels, by these phosphorothioate oligonucleotides was consistent with RNase H cleavage of RNA at the site of oligonucleotide hybridization. Chemically modified HCV antisense phosphodiester oligonucleotides were designed and evaluated for inhibition of core protein expression to identify oligonucleotides and HCV target sequences that do not require RNase H activity to inhibit expression. A uniformly modified 2'-methoxyethoxy phosphodiester antisense oligonucleotide complementary to the initiator AUG reduced HCV core protein levels as effectively as phosphorothioate oligonucleotide ISIS 6095 but without reducing HCV RNA levels. Results of our studies show that HCV gene expression is reduced by antisense oligonucleotides and demonstrate that it is feasible to design antisense oligonucleotide inhibitors of translation that do not require RNase H activation. The data demonstrate that chemically modified antisense oligonucleotides can be used as tools to identify important regulatory sequences and/or structures important for efficient translation of HCV.