cssi/SciSciGPT-SciSciNet huggingface dataset:
An Experimental Study on Security Protocols in Wlans

Wireless Local Area Networks (WLANs) are vulnerable to malicious attacks due to their open shared medium. Consequently, provisioning enhanced security with strong cryptographic features and low performance overhead becomes exceedingly necessary to actualize real-time services in WLANs. In order to exploit full advantage of existing security protocols at various layers, we study the cross-layer interactions of security protocols in WLANs under different network scenarios. In particular, we present a detailed experimental study on the integration of commonly used security protocols such as WEP, 802. lx and EAP, IPsec and RADIUS. First, we classify individual and hybrid policies, and then, define security index and cost functions to analyze security strength and overhead, quantitatively, of each policy. By setting-up an experimental testbed, we measure performance cost of various policies in terms of authentication time, cryptographic cost and throughput using TCP/UDP traffic streams. Our results demonstrate that in general, the stronger the security, the more signaling and delay overhead, whereas, the overhead does not necessarily increase monotonically with the security strength. Therefore, it is suggested to provide substantial security at a reasonable cost of overhead with respect to mobile scenarios and traffic streams. Also, we notice that authentication time will be a more significant factor contributing towards QoS degradation than cryptographic cost, which is critical to real-time service in wireless networks.
Style and substance: evidence for regionalism within the Aztec Market System

The emergence of the Triple Alliance empire and the consolidation of political power in the Basin of Mexico is traditionally associated with a high level of economic integration achieved through regional market exchange. Although researchers debate whether the market system was dominated by commercial factors or political forces, the assumption that the pax azteca led to a single, basin-wide exchange system is not generally challenged. Yet an increasing number of stylistic and compositional analyses indicate that significant regional subdivisions existed within the Aztec core, although the spatial scale, nature, and significance of these systems remains poorly understood. This study contributes to the body of evidence suggesting that economic divisions existed under the Triple Alliance, by presenting spatial patterning in Aztec Red Wares (guinda or rojo pulido) ceramics. By combining both stylistic and compositional analyses of this ceramic ware, it is possible to demonstrate both the strength of economic divisions as well as map their boundaries for a significant portion of the Basin. The regional patterns in artifact distribution highlighted in this and prior studies underscore the complexity of exchange interactions that evolved under Aztec rule and which must be explained by future models of the Aztec market system.
The Neutrophil-Lymphocyte Ratio and Survival During Left Ventricular Assist Device Support.

ABSTRACT Background: Systolic heart failure (HF) is a low-grade systemic inflammatory state. Neutrophil-lymphocyte ratio (NLR) is a nonspecific inflammatory marker with prognostic value in HF. We aimed to determine the relationship between NLR and mortality during left ventricular assist device (LVAD) support. Methods and Results: We retrospectively reviewed LVAD recipients implanted in the years 2010–2018. NLR was recorded before LVAD implantation and at intervals during LVAD support; pre-LVAD and 90-day LVAD NLRs were compared. Cox proportional hazard models were constructed to study the impact of NLR, both before LVAD implantation and at 90 days with LVAD, on mortality during subsequent LVAD support. Among 301 subjects, the median pre-LVAD NLR was 4.7 (interquartile range 3.0–8.0). Higher pre-LVAD NLR was independently associated with increased mortality during a median 324 days of LVAD support (adjusted hazard ratio [HR] 1.03, 95% confidence interval [CI] 1.01–1.06; P = .012, adjusted for pre-LVAD age, HF etiology, white blood count, hemoglobin, blood urea nitrogen, and sodium). After LVAD implantation, the NLR rose initially and then plateaued lower by day 90. Despite the mean decrease, higher 90-day LVAD NLR remained independently associated with increased mortality (adjusted HR 1.06, 95% CI 1.01–1.13; P = .033, stratified by early infection events). Conclusions: Higher pre-LVAD NLR is independently associated with mortality during LVAD support. NLR improves during LVAD support, but even accounting for early infections, a higher NLR at day 90 remains associated with subsequent mortality.
Differences in S/G ratio in natural poplar variants do not predict catalytic depolymerization monomer yields.

The ratio of syringyl (S) and guaiacyl (G) units in lignin has been regarded as a major factor in determining the maximum monomer yield from lignin depolymerization. This limit arises from the notion that G units are prone to C-C bond formation during lignin biosynthesis, resulting in less ether linkages that generate monomers. This study uses reductive catalytic fractionation (RCF) in flow-through reactors as an analytical tool to depolymerize lignin in poplar with naturally varying S/G ratios, and directly challenges the common conception that the S/G ratio predicts monomer yields. Rather, this work suggests that the plant controls C-O and C-C bond content by regulating monomer transport during lignin biosynthesis. Overall, our results indicate that additional factors beyond the monomeric composition of native lignin are important in developing a fundamental understanding of lignin biosynthesis. The ratio of syringyl (S) and guaiacyl (G) units in lignin has been regarded as a major factor in determining the maximum monomer yield. Here, the authors challenge this common conception using reductive catalytic fractionation in flow-through reactors as an analytical tool to depolymerize lignin in poplar with naturally varying S/G ratios.
Group Video Feedback is an Effective and Efficient Tool for Enhancing Skills of Surgical Interns

BACKGROUND Our group has shown that personalized video feedback (PVF) is better than a task demonstration video at increasing wound closure skills among incoming surgical interns. However, offering PVF can be time-consuming. We sought to compare the educational effects and time required for group video feedback (GVF) and PVF. METHODS We have mailed our matched incoming "surgical" interns a "welcome package" in mid-March for the past 3 y. The package includes similar resources each year. Incoming interns were asked to video record themselves performing six tasks three separate times between April 1 and June 15. After each submission in 2016 and 2017, incoming interns received 2 min of personalized feedback on their three separate wound closure videos (PVF). In 2018, incoming interns received 5 min of group-based feedback three separate times covering all six tasks (GVF). We compared performance (July Surgical Olympics) of these six skills against the interns from the previous 2 y who received PVF on only one skill (suturing). RESULTS Twenty-three incoming interns received the pre-residency package and participated in the 2018 Surgical Olympics. This 2018 GVF class had a higher overall mean score for six stations (31.5 [standard deviation = ±7.7]) than the 2016 and 2017 PVF classes (25.6 [standard deviation = ±8]; P < 0.0001). Knot tying ability and suturing skill were similar between the classes. The GVF group performed better on the remaining four skills . The total time of surgical staff and educators spent per class in 2018 (GVF class) was 30 min and includes six tasks compared with 276 min of effort in each of the 2016 and 2017 classes (PVF included one task). CONCLUSIONS GVF and PVF as a component of preemptive training had the same effect on improving suturing skills among the interns. GVF required less educator editing and voice over time. GVF is effective and efficient in enhancing incoming interns' performance in multiple skills.
Gene expression classification using L1 norm PCA

Gene microarray data generally includes high dimension, small sample datasets prone to noise. Analyzing this data using supervised and non-supervised learning algorithms is extremely useful for gene characterization, disease diagnosis, and genetic therapy in the medical field. For many years, principal component analysis (PCA) has been used as a tool in algorithms for gene expression classification. Previous solutions utilize L2 norm based PCA, however with its superior resistance to outlier data, L1 norm PCA offers improved results. Both methods are compared using support vector machines (SVM) to classify genetic mutations and co-regulation in several publicly available datasets. Methods utilizing L1 PCA result in improved accuracy compared to L2 PCA when used as a pre-processing step to SVM classification for gene microarray data.
The Host Galaxy of GRB 980703 at Radio Wavelengths—a Nuclear Starburst in an Ultraluminous Infrared Galaxy

We present radio observations of GRB 980703 at 1.43, 4.86, and 8.46 GHz for the period of 350-1000 days after the burst. These radio data clearly indicate that there is a persistent source at the position of GRB 980703 with a flux density of approximately 70 μJy at 1.43 GHz and a spectral index β ≈ 0.32, where Fν ∝ ν-β. We show that emission from the afterglow of GRB 980703 is expected to be 1-2 orders of magnitude fainter and therefore cannot account for these observations. We interpret this persistent emission as coming from the host galaxy—the first example of a γ-ray burst (GRB) host detection at radio wavelengths. We find that it can be explained as a result of a star formation rate (SFR) of massive stars (M > 5 M☉) of ≈140 M☉ yr-1, which gives a total SFR (0.1 M☉ < M < 100 M☉) of ≈750 M☉ yr-1. On the basis of these data alone we cannot rule out that some fraction of the radio emission originates from an obscured active galactic nucleus. Using the correlation between the radio and far-IR (FIR) luminosities of star-forming galaxies, we find that the host of GRB 980703 is at the faint end of the class of ultraluminous infrared galaxies, with LFIR ~ 1012 L☉. From the radio measurements of the offset between the burst and the host and of the size of the host, we conclude that GRB 980703 occurred near the center of the galaxy in a region of star formation. A comparison of the properties of this galaxy with radio and optical surveys at a similar redshift (z ≈ 1) reveals that the host of GRB 980703 is an average radio-selected star-forming galaxy. This result has significant implications for the potential use of a GRB-selected galaxy sample for the study of galaxies and the intergalactic medium at high redshifts, especially using radio observations, which are insensitive to extinction by dust and provide an unbiased estimate of the SFR through the well-known radio-FIR correlation.
Impact of an Educational Comic to Enhance Patient-Physician–Electronic Health Record Engagement: Prospective Observational Study

Background: Electronic health record (EHR) use can impede or augment patient-physician communication. However, little research explores the use of an educational comic to improve patient-physician-EHR interactions. Objective: To evaluate the impact of an educational comic on patient EHR self-advocacy behaviors to promote patient engagement with the EHR during clinic visits. Methods: We conducted a prospective observational study with adult patients and parents of pediatric patients at the University of Chicago General Internal Medicine (GIM) and Pediatric Primary Care (PPC) clinics. We developed an educational comic highlighting EHR self-advocacy behaviors and distributed it to study participants during check-in for their primary care visits between May 2017 and May 2018. Participants completed a survey immediately after their visit, which included a question on whether they would be interested in a follow-up telephone interview. Of those who expressed interest, 50 participants each from the adult and pediatric parent cohorts were selected at random for follow-up telephone interviews 8 months (range 3-12 months) post visit. Results: Overall, 71.0% (115/162) of adult patients and 71.6% (224/313) of pediatric parents agreed the comic encouraged EHR involvement. African American and Hispanic participants were more likely to ask to see the screen and become involved in EHR use due to the comic (adult P=.01, P=.01; parent P=.02, P=.006, respectively). Lower educational attainment was associated with an increase in parents asking to see the screen and to be involved (ρ=−0.18, P=.003; ρ=−0.19, P<.001, respectively) and in adults calling for physician attention (ρ=−0.17, P=.04), which was confirmed in multivariate analyses. Female GIM patients were more likely than males to ask to be involved (median 4 vs 3, P=.003). During follow-up phone interviews, 90% (45/50) of adult patients and all pediatric parents (50/50) remembered the comic. Almost half of all participants (GIM 23/50, 46%; PPC 21/50, 42%) recalled at least one best-practice behavior. At subsequent visits, adult patients reported increases in asking to see the screen (median 3 vs 4, P=.006), and pediatric parents reported increases in asking to see the screen and calling for physician attention (median 3 vs 4, Ps<.001 for both). Pediatric parents also felt that the comic had encouraged them to speak up and get more involved with physician computer use since the index visit (median 4 vs 4, P=.02) and that it made them feel more empowered to get involved with computer use at future visits (median 3 vs 4, P<.001). Conclusions: Our study found that an educational comic may improve patient advocacy for enhanced patient-physician-EHR engagement, with higher impacts on African American and Hispanic patients and patients with low educational attainment.
Coding Practices in Hand Surgery and Their Relationship to Surgeon Compensation Structure

Purpose To evaluate the coding practices of hand surgeons in the American Society for Surgery of the Hand with respect to practice compensation structure using common, representative hand surgery cases. Methods We developed a survey of demographic factors and 4 commonly encountered hypothetical hand surgery cases. This survey was emailed to the members of the American Society for Surgery of the Hand. Respondents were asked to code these cases using prepopulated applicable Current Procedural Terminology codes or any other codes of their choosing. The membership responses were then compared with those of 3 independent orthopedic coders. Results Of the 4,477 invitations sent, a total of 421 (9.4%) respondents completed the survey. There was notable heterogeneity in the Current Procedural Terminology code choices for the trapeziectomy and distal radius fracture cases. Physicians with a collections-based model coded for significantly higher work-related value units on average compared with the fixed salary– and relative value unit–based physicians for the trapeziectomy case (14.41 vs 13.65 and 13.67, respectively; P Conclusions The compensation model may be associated with coding practices for more complicated hand cases. The additional work-related value units potentially billed can quickly accumulate for frequently performed procedures. This wide variation supports a need for more frequent and accessible communication and education on coding practices in hand surgery. Clinical relevance Improved communication and education regarding appropriate coding practices as well as easily accessible reference material may assist in minimizing coding discrepancies for surgical hand procedures.
A UGT1A1 variant is associated with serum total bilirubin levels, which are causal for hypertension in African-ancestry individuals

Serum bilirubin is associated with several clinical outcomes, including hypertension, type 2 diabetes (T2D), and drug metabolism. Here, we describe findings from our genome-wide association studies (GWAS) of serum (TBIL) using a generalized linear mixed model in West Africans (n = 1127), with adjustment for age, sex, body mass index, T2D, significant principal components of population structure, and cryptic relatedness. Genome-wide conditional analysis and CAVIARBF were used to fine map significant loci. The causal effect of TBIL on hypertension was assessed by Mendelian randomization (MR) using the GWAS findings as instrumental variables (IVs) in African Americans (n = 3,067). The SNP rs887829 (UGT1A1) was significantly associated with TBIL levels (effect allele (T) frequency = 0.49, β (SE) = 0.59 (0.04), p = 9.13 × 10-54). Genome-wide conditional analysis and regional fine mapping pointed to rs887829 as a possible causal variant with a posterior inclusion probability of 0.99. The T allele of rs887829 is associated with lower hepatic expression of UGT1A1. Using rs887829 as an IV, two-stage least-squares MR showed a causal effect of bilirubin on hypertension (β = -0.76, 95% CI [-1.52, -0.01], p = 0.0459). Our finding confirms that UGT1A1 influences bilirubin levels. Notably, lower TBIL is causally associated with the increased risk of hypertension.
Caspian Sea Level and Anticipated Global Warming

According to many studies (Hansen et al., 1988; Schneider, 1990; Kellogg, 1991), the potential exists for significant increases in global air temperature to occur coupled with changes in global and regional patterns as a consequence of so-called ‘greenhouse effect’ increased by human activity. The basis for these predictions comes from general circulation model (GCM) output as a result of sensitivity studies associated with a CO, doubling. One of the most important consequences of human-induced climate change may be an alteration of the surface hydrologic balance, including changes in timing and magnitude of streamflow, evapotranspiration, soil moisture and ground-water recharge (Meehl and Washington, 1988; Rind, 1988; Thomas and Henderson-Sellers, 1992). It is obvious that if global warming is to materialize, this would significantly effect the CSL. However, the reaction of the CSL on anticipated global warming (even a possible direction of its change) is not clear.
Amyloid associated with elastin-staining laminar aggregates in the lungs of patients diagnosed with acute respiratory distress syndrome

The heterogeneity of conditions underlying respiratory distress, whether classified clinically as acute lung injury (ALI) or the more severe acute respiratory distress syndrome (ARDS), has hampered efforts to identify and more successfully treat these patients. Examination of postmortem lungs among cases clinically diagnosed as ARDS identified a cohort that showed a consistent morphology at the light and electron microscope levels, and featured pathognomonic structures which we termed elastin-staining laminar structures (ELS). Postmortem tissues were stained using the Verhoeff-Van Gieson procedure for elastic fibers, and with Congo red for examination under a polarizing microscope. Similar samples were examined by transmission EM. The pathognomonic ELS presented as ordered molecular aggregates when stained using the Verhoeff-van Gieson technique for elastic fibers. In several postmortem lungs, the ELS also displayed apple-green birefringence after staining with Congo red, suggesting the presence of amyloid. Remarkably, most of the postmortem lungs with ELS exhibited no significant acute inflammatory cellular response such as neutrophilic reaction, and little evidence of widespread edema except for focal intra-alveolar hemorrhage. Postmortem lungs that exhibit the ELS constitute a morphologically-identifiable subgroup of ARDS cases. The ordered nature of the ELS, as indicated by both elastin and amyloid stains, together with little morphological evidence of inflammation or edema, suggests that this cohort of ARDS may represent another form of conformational disease. If this hypothesis is confirmed, it will require a new approach in the diagnosis and treatment of patients who exhibit this form of acute lung injury.
Pathogenesis and mechanisms of antibody‐mediated hemolysis

Background The clinical consequences of antibodies to red blood cells (RBC) have been studied for a century. Most clinically relevant antibodies can be detected by sensitive in vitro assays. Several mechanisms of antibody-mediated hemolysis are well understood. Such hemolysis following transfusion is reliably avoided in a donor/recipient pair, if one individual is negative for the cognate antigen to which the other has the antibody.
Fatigue Crack Initiation in Threaded Fasteners Using the Critical Plane Approach

In this investigation, the stress and strain distributions at the first thread of a joint under cyclic uniaxial loads are examined by finite element analysis. The stress and strain histories of material elements along thethread surface are used in conjunction with multiaxial fatigue theories and the critical plane approach to determine the location, life, and direction of fatigue crack initiation for low cycle fatigue loading conditions. It is shown that fatigue cracks are initiated along the surface of the thread root at approximately 18° from the centerline of the thread shifted towards the loaded flank of the thread, and the inclination of the fatigue cracks are oriented at approximately 44° to the free surface of the bolt thread.
High-sensitivity interferometry of plasmas and gases in pulsed power experiments

Accurate measurements of plasmas and gases in pulsed power devices are needed so they can be used (or avoided) as desired. This paper reviews measurements of plasmas and gases using the high-sensitivity, two-color interferometer in use at the Naval Research Laboratory (NRL) since 1993. The instrument uses two cw Nd:YAG lasers at 1.064 and 0.532 /spl mu/m wavelengths that can be aligned along the same line-of-sight to simultaneously measure electron and neutral densities. This interferometer can measure optical path changes (phase shifts) as small as 10/sup -5/ waves. The interferometer's capabilities are illustrated by several examples, including the first measurement of electrons co-moving in vacuum with an intense proton beam, detection of gas turbulence, preionization of gas from a supersonic nozzle, and gas desorption from a metal surface exposed to intense UV.
Determination of aflatoxins B1, B2, G1, and G2 and ochratoxin A in ginseng and ginger by multitoxin immunoaffinity column cleanup and liquid chromatographic quantitation: collaborative study.

Botanical products are in great demand in health food markets. Botanicals are used for treatment of diseases as well as to promote health (1). Raw materials for medicinal use and herbal supplements frequently are contaminated with toxigenic fungi originating in the soil; the plants themselves are susceptible to fungal growth both pre- and post-havest under the right environmental conditions (2). Contamination with mycotoxins produced by these fungi could pose human health problems. In recent years, many incidences of natural occurrence of mycotoxins in botanicals have been reported (3). Aflatoxins (AF), the naturally occurring aflatoxins B1, B2, G1, and G2 (AFB1, AFB2, AFG1, AFG2), and ochratoxin A (OTA) have been found in ginseng, ginger, licorice, turmeric, and kava-kava in the United States (4, 5). Fumonisins have been found in medicinal wild plants in South Africa (6) and medicinal plants in Turkey (7) and Portugal (8). Zearalenone was identified in ginseng root (9). The presence of AF and OTA in botanicals may pose risks to human health. AF and OTA were found to co-occur in ginger (5). A multitoxin method for the determination of AF and OTA in botanical roots is needed. A method that is capable of determining AF and OTA simultaneously in powdered ginger and ginseng had been developed (5). The method uses a single immunoaffinity column for cleanup, high-performance liquid chromatography (LC) with post-column derivatization for AF fluorescence enhancement, and fluorescence determination for the toxins. The purpose of this collaborative study was to establish the accuracy, repeatability, and reproducibility parameters of the method by the analysis of spiked powdered ginseng and ginger and naturally contaminated powdered ginger.
Structure, composition, and defect control during plasma spray deposition of ytterbium silicate coatings

Environmental barrier coatings (EBCs) are needed to protect SiC structures exposed to high temperatures in water vapor-rich environments. Recent studies of a tri-layer EBC system consisting of a silicon layer attached to the SiC, a mullite diffusion barrier and a low-steam volatility ytterbium silicate topcoat have shown some promise for use at temperatures up to 1316 °C. However, the performance of the coating system appeared to be dependent upon the manner of its deposition. Here, an air plasma spray method has been used to deposit this tri-layer EBC on α-SiC substrates, and the effects of the plasma arc current and hydrogen content upon the structure, composition, and defects in ytterbium monosilicate (Yb2SiO5) and disilicate (Yb2Si2O7) topcoats are investigated. Modification of spray parameters enabled the loss of SiO from the injected powder to be reduced, leading to partial control of coating stoichiometry and phase content. It also enabled significant control of the morphology of solidified droplets, the porosity, and the microcracking behavior within the coatings. Differences between the Yb2SiO5 and Yb2Si2O7 are discussed in the context of their EBC application.
Attenuated neurodegenerative disease phenotype in tau transgenic mouse lacking neurofilaments.

Previous studies have shown that transgenic (Tg) mice overexpressing human tau protein develop filamentous tau aggregates in the CNS. The most abundant tau aggregates are found in spinal cord and brainstem in which they colocalize with neurofilaments (NFs) as spheroids in axons. To elucidate the role of NF subunit proteins in tau aggregate formation and to test the hypothesis that NFs are pathological chaperones in the formation of intraneuronal tau inclusions, we crossbred previously described tau (T44) Tg mice overexpressing the smallest human tau isoform with knock-out mice devoid of NFL (NFL−/−) or NFH (NFH−/−). Depletion of NF subunit proteins from the T44 mice (i.e., T44;NFL−/− and T44;NFH−/−), in particular NFL, resulted in a dramatic decrease in the total number of tau-positive spheroids in spinal cord and brainstem. Concomitant with the reduction in spheroid number, the bigenic mice showed delayed accumulation of insoluble tau protein in the CNS, increased viability, reduced weight loss, and improved behavioral phenotype when compared with the single T44 Tg mice. These results imply that NFs are pathological chaperones in the development of tau spheroids and suggest a role for NFs in the pathogenesis of neurofibrillary tau lesions in neurodegenerative disorders that contain both NFs and tau proteins.
Abstract 118: Right Bundle Branch Block and Clinical Outcomes in Patients with Heart Failure: A Systematic Review and Meta-analysis

Importance: Right bundle branch block (RBBB) is observed in approximately 5-14% of patients with heart failure (HF). Multiple observational studies have reported the association of RBBB with clinical outcomes in patients with HF. We performed a systematic review and meta-analysis to determine the prognostic significance of RBBB for patients with HF. Data Sources: We have systematically searched MEDLINE, EMBASE, Cochrane CENTRAL, Web of Science and Scopus through January 2014. Study Selection: Reviewers working independently and in duplicate screened all eligible abstracts that described all cause or cardiovascular mortality in patients with RBBB and HF. We excluded studies that reported unadjusted outcome, i.e.: unadjusted event rates. Knowledge synthesis: We pooled reported risk ratio and hazard ratio. Main Outcomes: All-cause mortality and cardiovascular mortality (death). Results: We found 12 relevant observational studies enrolling over 38,000 patients. Risk of bias was assessed using the Newcastle-Ottawa Scale. Included studies had at least a moderate quality. Seven of those evaluated prognosis of patients with RBBB and heart failure. After a mean follow up period of 2.5 years (range: 1-5 years), RBBB was associated with a statistically significant increased risk of all-cause mortality compared to patients with heart failure but no BBB, RR 1.27, 95% CI (1.08-1.50), Figure 1. The other 5 studies evaluated CHF patients receiving cardiac resynchronization therapy (CRT), comparing outcomes of patients with RBBB to those with LBBB. After a mean f/u period of 3 years, patients with RBBB were once again found to have an increased risk of all-cause mortality, RR 1.45, 95% CI 1.12-1.89. Conclusion and Relevance: RBBB in patients with HF is associated with higher all-cause mortality in comparison to patients without inter-ventricular conduction defects, as well as LBBB patients in patients undergoing CRT setting. ![][1] [1]: /embed/graphic-1.gif
Examining MRI contrast in three-dimensional cell culture phantoms with DNA-templated nanoparticle chains.

DNA-templated nanoparticle (NP) chains were examined as potential magnetic resonance imaging (MRI) contrast agents using in vitro environments of the extracellular matrix and tissue. A 3-T clinical MRI scanner was utilized to examine and compare image contrast enhanced by dispersed NPs, DNA-templated NP chains, gold-superparamagnetic multicomponent NP chains, and polyelectrolyte encapsulated, multicomponent NP chains in both T1-weighted and T2-weighted images. In addition, the longitudinal and transverse relaxivity (r1 and r2) changes were measured both in the basement membrane, using Matrigel, and in the tissue environment, using in vitro 3D cell culture scaffolds. Results suggest that MRI contrast was significantly enhanced from NP chains compared to dispersed NPs in the basement membrane and polyelectrolyte encapsulation for NP chains produced similar relaxivity to nonencapsulated NP chains due to the enhanced cell uptake of encapsulated NP chains.
Transesophageal atrial pacing threshold: Role of interelectrode spacing, pulse width and catheter insertion depth

This study evaluated the role of interelectrode spacing, pulse widths greater than 10 ms, and depth of esophageal insertion on minimizing transesophageal atrial pacing threshold in 30 patients aged 1 day to 77 years. Interelectrode spacings of 15, 22 and 28 mm were evaluated by establishing strength-duration curves in 2 or more serial studies in 12 patients; electrode spacing had no effect on pacing threshold. In 23 patients studied with 22-mm electrode spacing, pulse widths of 15 and 20 ms had no significant effect on current threshold requirements compared with 10-ms pulse widths. In 20 patients, pacing threshold and esophageal electrograms were obtained at 1.0- to 2.5-cm intervals with a 22-mm lead using a pulse width of 10 ms. Average minimal pacing threshold was 10.2 mA (range 4.5 to 20). The site of minimal pacing threshold was highly correlated with patient height (r = 0.987), and occurred within 1.1 cm (0 to 2.5 cm) of the site of the maximal bipolar atrial electrogram amplitude and 0.95 cm (0 to 3 cm) of the site of the maximal unipolar atrial electrogram. Bipolar electrode spacing of 15, 22 or 28 mm has little effect on transesophageal pacing threshold. In most patients, pulse widths greater than 10 ms do not significantly decrease pacing threshold. Correct catheter insertion depth is critical to minimize pacing threshold and may be predicted by either the site of the maximal atrial electrogram amplitude or patient height.
Is higher placement stability in kinship foster care by virtue or design

Prior research has repeatedly documented higher placement stability for children who enter kinship care rather than non-relative foster care. However, little is known about why, and under what circumstances, kinship care is more stable. This study uses longitudinal state administrative data to explore possible explanations. Results suggest that, while children in non-relative foster care are indeed at higher risk of any placement move than their peers in kinship care, this appears to be partly driven by child selection factors and policy preferences for kinship care. That is, the gap is not explained primarily by different rates of caregiver-requested moves. However, the gap was sizably smaller among select high-risk subgroups of foster children, suggesting that higher stability in kinship care may be partly explained by differences in the characteristics of children entering kinship care (versus non-relative foster care). Moreover, a large portion of the gap is explained by children in non-relative care being moved into kinship care; a move that is likely the result of policy preferences for kinship care rather than a defect in the initial placement. In sum, these results suggest that kinship care provides only a limited stability advantage, and the reasons for that advantage are not well understood.
Impacts of Dairy Diagnostic Teams on Herd Performance

This study evaluated impacts of educational diagnostic teams of consultants used to transfer technology to dairy farms. Herd management performance changes were measured by comparing Dairy Herd Improvement data from 38 project farms to data from herds that were geographical contemporaries. The value of focused goals for effecting change was also assessed. Interviews provided producers' perception of project outcomes and insight on organization and conduct of dairy diagnostic teams. Changes observed in project herds were small compared with controls with tendencies for increased herd size and improved milk production per cow. Focused goals had greater impacts on increasing herd size, milk per cow, first lactation peak milk, reducing age at first calving, and percentages of cows with subclinical mastitis. Time, money, facility limitations, labor, and alternative priorities were the most cited constraints to implementing changes. Satisfaction scores of producers were significantly related to the degree that team recommendations were followed. Improved attitudes, quality of life, and financial well-being were benefits listed by a majority of producers from participation in the project. If similar projects were to be offered, 83% said they would participate again, and 69% indicated they would pay at least some of the costs. Project farms served as demonstration farms for 1930 other producers in their respective locales, resulting in a multiplier effect of original advice given by consultant teams. Suggestions by farmer participants for improvements in dairy diagnostic teams included needs for at least some unbiased team members, more frequent meetings, more follow-up on recommendations, and consistency of recommendations with family goals.
Numerical analysis of the interaction of solute hydrogen atoms with the stress field of a crack

Finite element analysis is used to study the effect of mobile interstitial hydrogen on the deformation of metals and alloys in the case when hydrogen is in equilibrium with local stresses. The effect is studied by calculating the hydrogen atmosphere around a stationary crack tip in a linearly elastic isotropic material loaded in mode I plane strain conditions. Stresses, strains and equilibrium hydrogen concentrations are determined through an iterative finite element analysis while accounting for stress relaxation due to hydrogen induced local volume and elastic modulus changes. Numerical calculations reveal a zone immediately ahead of the crack tip in which the lattice is saturated with hydrogen. The dimensionless size of the saturation zone is found to be independent of the applied loads. The stiffness derivative method is used to calculate the hydrogen induced changes in the stress intensity factor. Calculations show that the presence of mobile interstitial hydrogen produces crack tip shielding when hydrogen induced changes in the elastic moduli are considered. The implications of the elastic analysis of the interaction between hydrogen in equilibrium with local stresses near a crack tip on the fracture resistance of materials are discussed. Then results are examined in conjunction with the elastic-plastic deformation at the tip.
Olfactometer and Procedure for Testing Baits and Chemical Attractants against Hippelates Eye Gnats

A simple new trap and olfactometer have been designed for screening and evaluating baits and chemical attractants against Hippelates eye gnats. The system has proved equally efficient against Milichiella species and several other small dipterous flies. The design of the trap was based on the phototropic and geotropic responses and olfactory behavior of the eye gnats. Various factors such as the lighting level of the funnel surface area and the depth of different types of bait dishes were found to influence the efficiency of the trap markedly. Increase in the lighting level in the funnel increased the entry of the gnats into the trap and the collection of gnats in the vial. Similarly, the use of shallower bait dishes having greater surface areas resulted in larger collections of gnats in the traps. The presence of an insecticide in the collection vial of the trap increased efficiency, and a number of insecticides were screened for quick knock-down and low repellency. Traps containing toxicants such as malathion, parathion, dicapthon, Dylox®, Korlan® and others gave larger collection of gnats than traps without insecticides in the vials. No marked difference in the gnat collections in the traps was observed when window screen (16 mesh) or hardware cloth (8 mesh) was used as trap support on a turntable in the open shade. However, traps having the coarser mesh screen support captured larger numbers of gnats than the traps with the finer mesh screen support and caught significantly higher numbers of gnats in the bait dish when the experiment was run in the open sun. The selection of one type of screen rather than another depends largely on the conditions under which experiments are to be performed.
Topographic amenities, building height, and the supply of urban housing

Abstract This article develops a housing supply model that treats explicitly the effects of location-specific amenities. The model employs a production function in which housing services are produced not only by structures, but also by access to and views of location-specific amenities. Housing supply is measured by building height. The model is tested with data from the city of Chicago. Access to and view of Lake Michigan are found to have a significant effect on the height of buildings.
Sex Attractant for the Bluegrass Webworm (Lepidoptera: Pyralidae)

Blends of (Z)-11-hexadecenal (Zl1-16:Ald) and (Z)-9-hexadecenal (Z9-16:Ald) were evaluated for their effectiveness in trapping male bluegrass webworms, Parapediasia teterrella (Zincken). Sticky traps baited with rubber septa containing a 20:1 blend of Zl1-16:Ald and Z9-16:Ald caught significantly more male bluegrass webworm adults than traps containing 200:3, 2:1, or 1:1 blends, or either compound alone, but not more than a 20:3 blend of the same compounds (Zl1-16:Ald/Z9-16:Ald). Males responded to a wide range of doses of the 20:1 blend (0.1-3 mg). This blend of Zl1/Z9-16:Ald provides an effective means of detecting the presence of males and may prove to be useful in monitoring the population size of an insect that is otherwise difficult to sample.
Design and testing of a prototype ohmic thawing unit

Abstract A significant proportion of seafood is imported into the U.S. in the form of frozen blocks. Before these can be further processed, they must be thawed, traditionally by immersion in warm water. This requires large amounts of fresh water, that become wastewater. It is also slow and potentially compromises the quality of the food. Ohmic heating can be used to thaw blocks. The major concern of this method is `runaway heating.' This occurs because electrical conductivity of frozen food is about two orders of magnitude lower than that of thawed food. The purpose of this study was to design, build and test an automated, computer controlled prototype ohmic thawing unit. Control circuitry was designed and custom built. Performance was tested with shrimp blocks.
Uptake and Metabolism of Leaf Proteins by the Silverleaf Whitefly

To determine if plant proteins can be ingested and metabolized by the silverleaf whitefly, whiteflies were fed artificial diets containing either 35 S-labeled cotton leaf proteins or a fluorescently labeled recombinant leaf protein. Confocal microscopy showed that whiteflies contained fluorescence throughout their digestive tracts and in their honeydew after feeding on fluorescently labeled protein. On diets containing radiolabeled protein, 35 S was ingested and either excreted as amino acids or retained in the body in protein and free amino acids. The profiles of radiolabeled whitefly polypeptides were similar for whiteflies feeding on labeled protein and labeled amino acids. Thus, whiteflies can ingest plant proteins, degrade them to free amino acids, and either excrete the amino acids or use them for de novo protein synthesis. Uptake and metabolism of radiolabel occurred when whiteflies fed on 35 S-labeled leaves. Honeydew from these insects contained a small amount of labeled protein. The label in honeydew protein was primarily associated with a 22.4 kDa polypeptide. This polypeptide co-migrated with a labeled whitefly polypeptide and its synthesis was inhibited by cycloheximide. The identity and function of this protein are unknown. Arch. Insect Biochem. Physiol. 39:155‐165, 1998. © 1998 Wiley-Liss, Inc.
On the factors affecting the initiation of protein synthesis in the rat ventral prostate: androgens, polyamines and conjugated proteins.

Abstract In the ventral prostate of certain strains of rats, androgens may have a very rapid effect on the initiation of protein synthesis by an antiandrogen sensitive process that may not be dependent on the synthesis of new RNA or protein. The primary effect appears to be at the step of met-tRNA f binding to the initiation factor EIF-1. Several stimulatory and inhibitory factors that can affect initiation factor activity are present in the prostate cytosol fraction. The low molecular weight inhibitory fraction contains polyamines which, at concentrations below 0.01 mM, can significantly inhibit this activity. The macromolecular effector fraction contains conjugated proteins (prostin H) that can destabilize met-tRNA f binding to initiation factor(s) and can also stimulate the incorporation of met-tRNA f into the newly synthesized protein. Upon enzymatic or acid proteolysis, prostin H releases the inhibitory components which behave like polyamines. It is possible that certain specific protein-bound polyamines play important roles in the hormonal regulation of protein synthesis in mammalian cells.
A Centromeric Satellite Sequence in the Pacific Oyster (Crassostrea gigas Thunberg) Identified by Fluorescence In Situ Hybridization

A highly repetitive satellite sequence was previously identified in the Pacific oyster Crassostrea gigas Thunberg. The sequence has 168 bp per unit, present in tandem repeats, and accounts for 1% to 4% of the genome. We studied the chromosomal location of this satellite sequence by fluorescence in situ hybridization (FISH). A probe was made by polymerase chain reaction and incorporation of digoxigenin-11-dUTP. Hybridization was detected with fluorescein-labeled antidigoxigenin antibodies. FISH signals were located at centromeric regions of 7 pairs of the Pacific oyster chromosomes. No interstitial site was found. Signals were strong and consistent on chromosomes 1, 2, 4, and 7, but weak or variable on chromosomes 5, 8, and 10. No signal was observed on chromosomes 3, 6, and 9. Our results showed that this sequence is clearly a centromeric satellite, disputing its previous assignment to the telomeric and submetacentric regions of 2 chromosomes. No signal was detected in the American oyster (Crassostrea virginica Gmelin).
A small KIM-1 based interactive music system

An interactive four voice organ simulator has been developed using a KIM-1 microcomputer with a 10K byte memory expansion. The basic organ simulator for the KIM-1 is that of Hal Chamberlin of Microcomputer Technology Unlimited. An interrupt driven event sequencer has been designed that allows interactive control of many aspects of the music production including tempo, volume, scale, and timbre (waveform harmonics).
Synthesis of 2-amino-3-O-(d-1-carboxyethyl)2-deoxy-d-galactose (d-galacto analog of muramic acid) and of its (l-1-carboxyethyl) analog☆

The synthesis of syrupy 2-amino-3-O-(d-1-carboxyethyl)-2-deoxy-d-galactose (“galactomuramic acid”) and of crystalline 2-amino-3-O-(l-1-carboxyethyl)-2-deoxy-d-galactose (“galactoisomuramic acid”), starting from benzyl 2-acetamido-4,6-O-benzylidene-2-deoxy-α-d-galactopyranoside, is described.
Shape functions for atomic-field bremsstrahlung from electrons of kinetic energy 1–500 keV on selected neutral atoms 1 ≤ Z ≤ 92

Abstract A tabulation is presented of theoretical predictions for the shape functions for atomic-field bremsstrahlung for 24 atoms with atomic number Z ranging from 1 to 92 for six incident electron energies T1 from 1 to 500 keV. The shape function is defined as the ratio of the bremsstrahlung cross section differential in photon energy and angle to the photon energy spectrum. Shape functions have been tabulated for photon angles from 0° to 180° in 5° intervals for 12 values of the fraction of energy radiated /T1 from 0 to 1.0. The tables for2 ≤ Z ≤ 92 result from interpolations in atomic number and fraction of energy radiated from a set of benchmark data calculated by treating the bremsstrahlung process as a single-electron transition in a relativistic self-consistent screened potential. The table for Z = 1 is calculated using a screened Born approximation.
Energy and investment: An empirical examination

Abstract The view that the investment function is characterized by a stable relationship is subjected to an objective statistical test. The test utilizes a statistic which equals the ratio of the sum of squared residuals of one-period prediction from the k + 1 period to the r th period to the sum of squared residuals of one period prediction from the k + 1 to the T th period, where k is the number of estimated coefficients in the model and T is the sample size. The results for the period 1947–1979 suggest that the investment function at the macroeconomic level and for 8 of the 11 two-digit SIC industries considered became unstable in 1973. For the other two-digit SIC industries investigated, the results indicate no appreciable (statistically significant) change in the relative importance of the underlying investment determinants.
Fall- and Spring-Applied Poultry Litter Effectiveness as Corn Fertilizer in the Mid-Southern United States

The effectiveness of fall- or winter-applied poultry litter, relative to spring-applied litter, as row crop fertilizer in the southern and southeastern United States has not been well researched. A 3-yr field study was conducted in northern Mississippi to determine the effectiveness of litter as corn (Zea mays L.) fertilizer and quantify loss of its potency when applied in the fall. The grain yield and biomass of corn that received fall-applied poultry litter (9 or 18 Mg ha–¹) or 202 kg ha–¹ NH₄NO₃–N was compared against that of corn that received the same fertilization treatments applied in the spring including an unfertilized control. Corn fertilized with 18 Mg ha–¹ litter applied in the spring produced 24% less grain yield in the first year but up to 21% more grain yield in the last 2 yr than corn fertilized with spring-applied NH₄NO₃. Unlike the common assumption that 50 to 65% of the total litter N is available in the same year of application, we estimated only 31% of the total N from 18 Mg ha–¹ spring-applied litter was available to corn in the first year. Applying 18 Mg ha–¹ litter in the fall, relative to spring, reduced grain yield by 12.8% and biomass by 15.0% when averaged across the 3 yr. These results show that applying poultry litter in the fall in regions with warm fall and winter months similar to that of northern Mississippi reduces its value as a fertilizer and could potentially increase environmental risk.