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BACKGROUND Dural arteriovenous fistulas (dAVFs) are direct, aberrant connections between dural arteries and cerebral veins. In neonates, delayed diagnosis results in grim outcomes. Treatment involves endovascular management because of its success and tolerability. Here, the authors present a case of a complex dAVF initially recognized with an in utero neurosonogram and fetal magnetic resonance imaging (MRI). OBSERVATIONS A 21-week fetal ultrasound of a nonspecific brain mass was confirmed with fetal MRI as a 2.7-cm T1-hyperintense posterior fossa mass. Although a large flow void in the left middle cranial fossa was present, postnatal computed tomography angiography ultimately revealed a high-flow dAVF communicating with the left transverse sinus. In the early postnatal period, the patient developed hydrocephalus. After successful partial embolization, 6-week postangiogram brain MRI indicated disease progression with the development of a venous varix causing brainstem compression. Repeat embolization resulted in complete cessation of early venous drainage. LESSONS Neonatal dAVFs are exceedingly rare and result in futile outcomes; however, detection in utero is possible. Although definitive therapy must be performed postnatally, constant monitoring and early delivery can prevent complications. Attention to fetal ultrasound is essential, and knowledge of fetal MRI in the detection of these complex lesions can significantly improve outcomes.

To prospectively validate a method to accurately and rapidly differentiate normal from abnormal spinal bone mineral density (BMD) using colored abdominal CT images.For this prospective observational study, 196 asymptomatic women ≥ 50 years of age presenting for screening mammograms underwent routine nonenhanced CT imaging of the abdomen. The CT images were processed with software designed to generate sagittal colored images with green vertebral trabecular bone indicating normal BMD and red indicating abnormal BMD (low BMD or osteoporosis). Four radiologists evaluated L1/L2 BMD on sagittal images using visual assessment of grayscale images, quantitative measurements of mean vertebral attenuation, and visual assessment of colored images. Mean BMD values at L1/L2 using quantitative CT with a phantom served as the reference standard. The average accuracy and time of interpretation were calculated. Inter-observer agreement was assessed using intraclass correlation coefficient (ICC).Mean attenuation at L1/L2 was highly correlated with mean BMD (r = 0.96/0.91, p 0.001 for both). The average accuracy and mean time to assess BMD among four readers for differentiating normal from abnormal BMD was 66% and 6.0 s using visual assessment of grayscale images, 88% and 15.2 s using quantitative measurements of mean vertebral attenuation, and 92% and 2.1 s using visual assessment of colored images (p 0.001 and p 0.001, respectively). Inter-observer agreement was poor using visual assessment of grayscale images (ICC:0.31), good using quantitative measurements of mean vertebral attenuation (ICC:0.73), and excellent using visual assessment of colored images (ICC:0.90).Detection of abnormal BMD using colored abdominal CT images was highly accurate, rapid, and had excellent inter-observer agreement.

This paper describes realization of a prototype discrete-frequency self-contained NQR system into a small portable battery powered form-factor capable of detecting and classifying explosive ingredients such as sodium nitrite, ammonium nitrate, RDX, HMX, PETN, potassium nitrate, tetryl, urea nitrate, and glycine. Size is similar to the smallest commercially available NMR spectrometer, but includes all system components. This version uses fixed frequencies and simple pulse sequences to prove feasibility. Results include signature amplitude variation as a function of both sample mass and standoff, and detection unaffected by presence of both metallic and non-metallic clutter.

Co-located, high power RF transmitters create interference for out-of-band neighboring receivers through nonlinear intermodulation. Diverse, frequency-agile radios complicate compatibility testing by requiring a broad array of test equipment and engineering expertise to deliver robust quality of service. A new test system in development, the Nonlinear Automated Measurement System (NAMS), is presented to address the challenge of automated testing over the broad range of transmit and receive bands used by current and future radio-dense military platforms. The current NAMS hardware prototype is shown to achieve broadband, high dynamic range performance through the use of software-defined analog signal cancellation and linear system design. A predistortion canceller in development has the potential to further expand the state-of-the-art measurement capability.

Thousands of children are adopted into the United States each year, many of whom have spent a significant portion of their pre adoptive lives in an institutional setting. Post-institutionalized (PI) children adopted into the United States are often referred for mental health services at higher rates than other groups of children. There is a lack of research examining differences in clinically referred PI children and other groups. The purpose of this study was to address this gap in knowledge. Results from multiple analysis of covariance and follow-up pairwise contrast analyses found significant differences only between PI and domestic adoptees (DA). Specifically, DA exhibited poorer functioning in the areas of attention problems and social problems. Mean scores were above the 85th percentile for all indicators for all groups, indicating the severity of psychosocial problems for the sampled group of clinical referrals. More research is needed that compares the psychosocial problems of PI children to other...

Micromachined millimeter-wave anti-reflective layers (mm-AR) offer a highly customizable and effective method to maximize power transmission through dielectric media. The power transmitted through an air-dielectric interface is maximized by adding an anti-reflective layer whose thickness is a quarter-wavelength and whose dielectric constant is the geometric mean of air and the dielectric, in analogous fashion to a quarter-wave transformer in transmission line theory. The mm-AR is an artificial dielectric material with controlled thickness and dielectric constant. A DRIE process forms a sub-wavelength lattice in a substrate that controls the material's effective dielectric response. The resulting anti-reflective layers were used to improve transmission through a silicon-air interface from an average of 40% across the W-band to 95%. While silicon was used in this work, the demonstrated impedance matching technique can be used for a wide variety of dielectric materials.

RAND conducted an end-to-end review and analysis of Department of Defense civilian deployment to inform policy and practice for using deployable civilians to meet mission needs ten to 20 years into the future.

The Marine Corps Combat Development Command asked RAND to study the integration of women into infantry combat roles. Researchers reviewed the literature, conducted interviews, estimated costs, and developed an approach for monitoring integration.

Traditional FMCW theory with a chirped radar signal assumes that the measured return after mixing is a sinusoid whose frequency is a function of the distance to the reflecting objects. The broadband nature of chirped radar exposes the fact that components in the system are not equally efficient at all frequencies. This paper describes the theory behind modeling a chirped radar measured return as an AM message with a carrier tone and presents measurements for support.

In the last decade, GaN-on-Si has progressed from fundamental crystal growth studies to product realization and reliability demonstration. GaN-on-Si HEMTs addressing cellular, WiMAX, and broadband RF applications are now commercially available and offer GaN performance attributes in a cost-competitive platform. This presentation will briefly describe the underlying GaN-on-Si material, process, and packaging technology, then focus primarily on performance of these products in both commercial and military applications.All Nitronex NRF1 GaN-on-Si products are grown by MOCVD on 100 mm float-zone Si (111) substrates. A proprietary, strain-compensating (Al,Ga)N transition layer and an amorphous SixAl1-xNy nucleation layer are employed to accommodate lattice and thermal expansion mismatch between the substrate and the epilayers. The wafer fabrication process employs Ti/Al-based ohmic contacts, ion implant device isolation, 0.5 um dielectrically-defined gates, gold airbridge interconnects, and through-wafer source vias. Typical inline DC parametrics include 2DEG sheet resistance of 490 ohms/sq., on-resistance of 3 ohm-mm, peak drain current density of 830 mA/mm, and breakdown voltage of >100V. Packaging solutions include traditional LDMOS-style air cavity outlines with thermally-enhanced flange materials and low-cost plastic SOIC.A family of devices addressing emerging OFDM-based applications such as WiMAX has been developed. WiMAX amplifiers require several watts of linear output power with frequency band allocations ranging from 2.3 to 5.8 GHz and instantaneous bandwidth up to ∼15%. Translated to the transistor level, this implies simultaneous high frequency and high voltage capability – attributes well-suited to the inherent advantages of GaN-based devices. The flagship product in this family is NPT25100, delivering 125W of peak envelope power at 2.5 GHz. Under 2.5 GHz single-carrier OFDM modulation and 10 MHz channel bandwidth, this device produces 10W linear power at 2.0% EVM with 16.5dB associated gain and 26% drain efficiency. The excellent bandwidth of NRF1 devices enables the same device to operate at cellular frequencies from 2.11 - 2.17 GHz, producing >20W average power at an adjacent channel power ratio of -35 dBc.Primary military insertion opportunities include communications (e.g., JTRS - Joint Tactical Radio System) and electronic warfare (e.g., jammers). For EW applications, broadband operation reduces system-level component count and decreases weight / footprint. A family of 48V GaN-on-Si broadband HEMTs has been developed to deliver power levels from 40W - 180W in a compact package. In the highest power case, packaged “power density” (defined as peak output power divided by package volume) reaches ∼650 W/cm3. These power levels – in an outline suitable for highly portable systems – enable improved communications transmit distance and extend the umbrella size of electronic protection units.

Although the term attachment disorder is ambiguous, attachment therapies are increasingly used with children who are maltreated, particularly those in foster care or adoptive homes. Some children described as having attachment disorders show extreme disturbances. The needs of these children and their caretakers are real. How to meet their needs is less clear. A number of attachment-based treatment and parenting approaches purport to help children described as attachment disordered. Attachment therapy is a young and diverse field, and the benefits and risks of many treatments remain scientifically undetermined. Controversies have arisen about potentially harmful attachment therapy techniques used by a subset of attachment therapists. In this report, the Task Force reviews the controversy and makes recommendations for assessment, treatment, and practices. The report reflects American Professional Society on the Abuse of Children's (APSAC) position and also was endorsed by the American Psychological Association's Division 37 and the Division 37 Section on Child Maltreatment.

Objectives To determine the effects of prolonged ventilation tube retention on tympanic membrane healing and the efficacy of patching procedures used concomitantly at the time of tube removal. Design Retrospective chart review. Setting Tertiary referral academic institution. Patients Seventy-six patients aged 12 years and younger, with a total of 99 ears identified from January 1989 to December 1994. All patients underwent ventilation tube removal for prolonged tube retention or infection unresponsive to medical management. A minimum of 6 months of follow-up was required for inclusion. Intervention Ventilation tube removal under general anesthesia, with or without concomitant patching. Outcome Measures All medical charts were reviewed for age, sex, indications for tube removal, tube retention time, type of patch used (if any), type of tube, outcome after removal, other medical problems, and previous surgical history. Results The perforation rate was significantly higher in children with tubes retained beyond 36 months ( P =.02). History of previous adenoidectomy predicted poor outcome, with a rate of 47% vs 17% in patients with no such history ( P =.002). Patching did not improve healing. No other patient factors significantly influenced the perforation rate. Conclusions Ventilation tube retention longer than 36 months resulted in an increased perforation rate after surgical removal. Paper patching at the time of tube removal does not improve healing. Prospective studies are needed to confirm these findings and to determine the efficacy of other patching techniques.