cssi/SciSciGPT-SciSciNet huggingface dataset:
Thermal Conductance of β-Ga 2 O 3 /Metal Interfaces

The wide-bandgap semiconductor β-Ga 2 O 3 is of growing interest for high power devices. Its thermal conductivity, however, is an order of magnitude lower than commonly used semiconductors such as Si, SiC, and GaN. Thermal management is thus a central issue in device design. Our objectives in this study are twofold. First, we measure the thermal conductance of the interfaces that β-Ga 2 O 3 forms with the metal layers that serve as source and drain. These interfaces may be barriers to effective heat removal and prevent optimal performance. Second, we use theoretical tools to investigate the bulk properties of the α, β, and e phases of Ga 2 O 3 . The thermal conductance of the Au/β-Ga 2 O 3 interface is measured using frequency-domain thermoreflectance to be 45±5 and 80±8 MW/m2-K for e-beam evaporated and sputtered Au layers. To increase the thermal conductance, an adhesion layer of Ti or Cr of thickness up to 10 nm is deposited between the β-Ga 2 O 3 and the Au. The relationship of thermal conductance vs. adhesion layer thickness is finely determined for Ti and Cr. Depending on the adhesion layer material and thickness, the thermal conductance can be increased by as much as 10 times. The results are interpreted by considering the phonon density of states overlap. We apply molecular dynamics simulations to predict the lattice parameters, bulk modulus, and thermal conductivity tensor of the three bulk phases of Ga 2 O 3 . Our predictions for the β phase match experimental results with less than 10% error. The lattice parameters of both α and e phases of Ga 2 O 3 are within 5% error from experimental results (the other properties have not been measured). Despite the same chemical composition, we predict that the e phase thermal conductivity is an order of magnitude lower than the α and β phases.
Has Rotavirus Vaccination Decreased the Prevalence of Biliary Atresia

Objectives:Biliary atresia (BA) is a rare neonatal liver disease that causes cholestasis and is the leading indication for pediatric liver transplantation. Although the exact etiology of BA remains unknown, evidence from murine models supports the role of rotavirus infection in the development of BA
Camp or College

The purpose of this paper is to investigate student perspectives of how college computer science (CS) programs compare to those of coding bootcamps. In particular, the research examines to what degree students report their respective programs instill the necessary interpersonal and intrapersonal skills (i.e., teamwork and resilience) necessary for workforce entry. Prior research from the authors suggests there is a perception among the software industry that college graduates often lack the necessary so-called "soft" skills for successful workforce entry; this research investigates to what degree students from each educational environment mirror this sensibility in the assessment of their own abilities, learning preferences, and educational experiences. Data is based on a series of fifty (50) one-on-one interviews with students, 22 of whom come from a coding bootcamp background and 28 who come from a four-year college. Alongside these interviews, students completed both pre-surveys (50 students) and post-surveys (19 students) on learning preferences and programmatic experience; 12 students also participated in follow-up interviews further articulating their learning experiences. Results indicate that despite significant differences in age and workforce experience, coding bootcamp students and undergraduates differ little in how they perceive themselves as learners; there were notable differences in reasons for application to respective programs as well as exposure to practical learning experiences through coursework. Discussion focuses on the degree to which the aforementioned "soft skills" are perceived as learned expertise versus a personal attribute, and to what degree such perception may contribute to higher education's pedagogical and curricular approaches to CS instruction.
CD49f is a novel marker to purify functional human iPSC-derived astrocytes

Astrocytes play a central role in the central nervous system (CNS), maintaining brain homeostasis, providing metabolic support to neurons, regulating connectivity of neural circuits, and controlling blood flow as an integral part of the blood-brain barrier. They have been increasingly implicated in the mechanisms of neurodegenerative diseases, prompting a greater need for methods that enable their study. The advent of human induced pluripotent stem cell (iPSC) technology has made it possible to generate patient-specific astrocytes and CNS cells using protocols developed by our team and others as valuable disease models. Yet isolating astrocytes from primary specimens or from in vitro mixed cultures for downstream analyses has remained challenging. To address this need, we performed a screen for surface markers that allow FACS sorting of astrocytes. Here we demonstrate that CD49f is an effective marker for sorting functional human astrocytes. We sorted CD49f+ cells from a protocol we previously developed that generates a complex culture of oligodendrocytes, neurons and astrocytes from iPSCs. CD49f-purified cells express all canonical astrocyte markers and perform characteristic functions, such as neuronal support and glutamate uptake. Of particular relevance to neurodegenerative diseases, CD49f+ astrocytes can be stimulated to take on an A1 neurotoxic phenotype, in which they secrete pro-inflammatory cytokines and show an impaired ability to support neuronal maturation. This study establishes a novel marker for isolating functional astrocytes from complex CNS cell populations, strengthening the use of iPSC-astrocytes for the study of their regulation and dysregulation in neurodegenerative diseases.
Combinatorial Effects of CD30 Ligand Stimulation or Inhibitor of Apoptosis (IAP) Antagonist Exposure with Conventional Chemotherapy on CD30 Positive Malignancies

Abstract 4926 CD30 is a member of the tumor necrosis factor (TNF) receptor family that is normally found on the cell surface of a small subset of activated lymphocytes but is overexpressed on the surface of anaplastic large cell lymphoma (ALCL) and Hodgkins lymphoma (HL) cells. Although many drugs exist that treat lymphomas by triggering the intrinsic cell death pathway, current chemotherapeutic regimens are limited by unwanted side effects, including secondary malignancies that limit event-free survival. The tumor-restricted overexpression of CD30 makes it an attractive target for therapeutic intervention. Depending on the cellular context, CD30 stimulation has been linked to cell death, cell cycle arrest, or paradoxically, proliferation. In ALCL tumor cell lines, CD30 stimulation activates both the canonical and noncanonical NF-kB pathways while in HL tumor cell lines, CD30 stimulation only slightly enhances NF-kB activity above constitutive levels, implying a role for NF-kB in determining the sensitivity or resistance of lymphoma cells to CD30-induced apoptosis. In addition, IAP antagonists, small synthetic compounds that mimic the structure of the second mitochondrial activator of caspase (Smac) and target IAP molecules that affect the activation of the non-canonical NF-kB pathway, induce apoptosis and/or sensitize cells to death via secondary signals such as TNF. This suggests that the modulation of IAP levels, and consequently regulation of the non-canonical NF-kB pathways, may also have a role in determining tumor cell death. Using representative ALCL and HL tumor cell lines, we have found that CD30 stimulation via its physiologically ligand in combination with standard chemotherapeutic agents results in increased efficacy in tumor cell death in the majority of ALCL cell lines but not HL cell lines. Similarly, IAP antagonists in combination with standard chemotherapeutic agents also resulted in enhanced tumor cell death in most ALCL but not HL cell lines. This augmentation of tumor cell death suggests that CD30-induced apoptosis and IAP antagonist-induced killing may have important consequences in the clinical treatment of CD30 positive malignancies. Currently, we are further investigating the role of both CD30 stimulation via its physiological ligand and IAP antagonists in impacting the activation of the canonical and noncanonical NF-kB pathways alone and in combination with currently utilized chemotherapeutic agents to modulate the apoptotic threshold in CD30 positive lymphoma cells. Disclosures: No relevant conflicts of interest to declare.
Antiidiotypic Response Against Murine Monoclonal Antibodies Reactive with Tumor-Associated Antigen TAG-72

The immune response of 42 gastrointestinal and ovarian cancer patients at 1 month after exposure to murine monoclonal antibodies (B72.3 and CC49) reactive with the tumor-associated antigen TAG-72 was studied. The incidence of human anti-mouse antibody response was 89% to B72.3 and 70% to CC49. To evaluate the antiidiotypic immune response, we developed a serological assay based on affinity chromatography to remove the interference due to the presence of TAG-72, antiisotypic, and antiallotypic immunoglobulins in the serum. Seventy-eight percent of patients who received B72.3 developed an antiidiotypic response; in 33% of the patients, this was the only immune response detected. The antiidiotypic immune response after treatment with CC49 was present in 54% of the patients. Twelve percent of the patients who received CC49 developed an antiidiotypic response in the absence of antiisotypic or antiallotypic immune response. The lower immunogenicity of the variable region of CC49 is encouraging when considering the use of chimeric or humanized antibodies derived from the murine monoclonal antibody CC49 in clinical studies.
Learning Norms from Stories: A Prior for Value Aligned Agents.

Value alignment is a property of an intelligent agent indicating that it can only pursue goals and activities that are beneficial to humans. Traditional approaches to value alignment use imitation learning or preference learning to infer the values of humans by observing their behavior. We introduce a complementary technique in which a value aligned prior is learned from naturally occurring stories which encode societal norms. Training data is sourced from the childrens educational comic strip, Goofus and Gallant. In this work, we train multiple machine learning models to classify natural language descriptions of situations found in the comic strip as normative or non normative by identifying if they align with the main characters behavior. We also report the models performance when transferring to two unrelated tasks with little to no additional training on the new task.
Abstract C22: Loss of KDM6A promotes pancreatic cancer progression by upregulating epithelial-mesenchymal transition pathway

Metastasis is one of the main reasons for poor survival in patients with pancreatic ductal adenocarcinoma (PDA). However, the molecular mechanism of PDA metastasis remains elusive. Recent studies failed to find metastasis-specific genetic mutations, and thus suggested that aberrant epigenetic regulation may be one of the crucial mechanisms. Many epigenetic regulator genes are altered in PDA, including KDM6A, a histone H3K27 demethylase, which has been identified by whole-genomic mutational analyses as a driver of PDA. Recent studies have shown that loss of KDM6A induces aggressive squamous-like PDA by activing superenhancers and promotes metastasis. However, the underlying mechanism by which KDM6A promotes metastasis remains elusive. Using stable KDM6A knockout PDA cell lines established by CRISPR/Cas9 system and siRNA, we knocked out or knocked down the expression of KDM6A in PDA cells. We also established an inducible KDM6A re-expressed PDA cell line that has homozygous KDM6A deletion. A novel Bru-seq technology was used to determine global changes of nascent RNA synthesis in KDM6A-null cells. Cell migration and invasion was assessed in vitro. To study the impact of KDM6A loss in vivo, we crossed KDM6Afl/fl mice with the well-established Ptf1aCre; Kras G12D; p53 R172H (KPC) PDA mouse model. Bru-seq data have shown that epithelial-mesenchymal transition (EMT) pathway is highly upregulated in KDM6A knockout cells and downregulated in KDM6A re-expressed PDA cells. EMT is a well-known process that is involved in tumor metastasis. KDM6A knockout cells demonstrated decreased cell proliferation but increased cell migration and invasion with mesenchymal cell morphology changes in vitro. Hallmark epithelial marker E-cadherin was significantly downregulated in KDM6A knockout cells, supporting the EMT process. Furthermore, genetic mouse model showed that mice that lose KDM6A expression developed PDA and metastasis much earlier than KPC mice. The morphology of the PDA developed in KDM6A-null KPC mice is more sarcomatoid or mesenchymal compared to PDA in KPC mice. Immunohistochemistry analysis also demonstrated loss of epithelial marker E-cadherin and gain of mesenchymal marker vimentin in tumor cells. In summary, these results suggest that loss of KDM6A promotes PDA development and metastasis by upregulating EMT signaling. These data linked epigenetic regulation to EMT signaling and provided insights into the role of KDM6A in PDA development. These novel findings also provided foundation for developing new therapeutic strategies. Citation Format: Sivakumar Jeyarajan, Zhujun Yi, Shanqiao Wei, Shuang Lu, Hong Kim, Michelle Paulsen, Karan Bedi, Mats Ljungman, Jiaqi Shi. Loss of KDM6A promotes pancreatic cancer progression by upregulating epithelial-mesenchymal transition pathway [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr C22.
In Limited Demand: The Other Foreign Volunteers in the Syrian Civil War

ABSTRACTThe wars in Syria and Iraq attracted about 45,000 individuals from outside the arenas. Most joined the Islamic State, but interestingly, other prominent armed groups showed less interest in...
Virtual screening by 2-D fingerprints, shape and docking for discovering new chemotypes of activator protein-1 inhibitors

Activator protein-1 Fos/Jun proteins bind to cognate DNA and regulate gene expression. Small-molecule inhibitors targeting activator protein-1 DNA binding have been developed in the past decades fo...
The Secret Life of Testamentary Schemes

The testamentary scheme, a poorly understood interpretative tool used by courts to determine the meaning of a will’s dispositive provisions, is insufficiently theorized in both case law and scholarly commentary. Based on a painstaking study of testamentary schemes in context, in this article I raise and defend three propositions: (1) a testamentary scheme is a dominant purpose that is intrinsic to the will; (2) a testamentary scheme is most appropriately used (a) to bring plain language into sharper focus or (b) to fill omissions in dispositive provisions; and (3) if a testamentary scheme can do either (2)(a) or (2)(b), there is no need to resort to evidentiary presumptions.
Chapter 4 – Attention

Attention skills include noticing or attending to salient stimuli and events when they are presented or occur in the environment. Learners with sharp attention skills are able to distinguish between stimuli that deserve attention versus stimuli that should be ignored, and they are able to disengage with unimportant stimuli to continue to attend to those that are important. As learners continue to advance in grade level, their attention skills will be tested greatly, as they will need to be able to multitask and shift their attention between stimuli. This chapter presents step-by-step lessons that can help practitioners, educators, and parents teach children to sustain their attention to tasks such as morning and evening routines, homework, practicing sports or musical instruments, puzzles, constructive play activities, and projects of any kind. Data sheets, worksheets, and graphs are also provided for monitoring progress.
At scale, renewable natural gas systems could be climate intensive: the influence of methane feedstock and leakage rates

Renewable natural gas (RNG) is a fuel comprised of essentially pure methane, usually derived from climate-neutral (e.g., biogenic or captured) carbon dioxide (CO2). RNG is proposed as a climate friendly direct substitute for fossil natural gas (FNG), with the goal of enabling diverse natural gas users to continue operating without substantial infrastructure overhauls. The assumption that such substitution is climate friendly relies on a major condition that is unlikely to be met: namely, that RNG is manufactured from waste methane that would otherwise have been emitted to the atmosphere. In practice, capturable waste methane is extremely limited and is more likely to be diverted from a flare than from direct atmospheric release in a climate-conscious policy context, which means that RNG systems need to be more destructively efficient than a flare to provide climate benefits versus the likely alternative management strategy. Assuming demand levels consistent with the goal of using existing FNG infrastructure, RNG is likely to be derived from methane that is either intentionally produced or diverted from a flare, so essentially any methane leakage is climate additional. Further, in a decarbonizing system, RNG will likely compete with lower-emissions resources than FNG and thus provides fewer net emissions benefits over time. Anticipated leakage is climatically significant: literature estimates for methane leakage from biogas production and upgrading facilities suggest that leakage is in the 2-4% range (mass basis), up to as much as 15%. Policy makers should consider that under reasonable leakage and demand assumptions, RNG could be climate intensive.
Romantic Self-Transformation in Kierkegaard

Kierkegaard adapts conceptual resources from both early German Romanticism and Hegelianism. The adaptation in question triangulates these resources, such that certain elements of Romantic thought that are critical with regard to Hegel and certain aspects of Hegel’s thought that are critical of Romanticism combine in Kierkegaard. Specifically, he crafts a conception of dialectical transition by repurposing Romantic conceptions of irony and Hegelian conceptions of humor. Moving between what Kierkegaard calls the existential spheres involves these indirect modes of self-address, which in turn prompt “leaps” of radical self-transformation, that is, changes between types of selves.
Upper pole hemi-nephrectomy

Abstract The goals of management of ureteroceles are to preserve renal function; to eliminate infection, obstruction, VUR; and to preserve urinary continence. Although there are controversies as to which surgical approach is best, there is a consensus that an individualized plan should be formulated to address the above goals with the intent of achieving them with the least morbidity and number of stages. Upper pole hemi-nephrectomy remains a viable option in the management of patients with ureteroceles subtending a non-functioning or poorly functioning duplex kidney. When indicated, several open or minimally invasive modalities can be used. Surgical specialists should become experienced in the various approaches and when to use them.
Sterile Spikelets Contribute to Yield in Sorghum and Related Grasses

Sorghum (Sorghum bicolor) and its relatives in the grass tribe Andropogoneae bear their flowers in pairs of spikelets in which one spikelet (seed-bearing or sessile spikelet [SS]) of the pair produces a seed and the other is sterile or male (staminate). This division of function does not occur in other major cereals such as wheat (Triticum aestivum) or rice (Oryza sativa). Additionally, one bract of the SS spikelet often produces a long extension, the awn, that is in the same position as, but independently derived from, that of wheat and rice. The function of the sterile spikelet is unknown and that of the awn has not been tested in Andropogoneae. We used radioactive and stable isotopes of carbon, RNA sequencing of metabolically important enzymes, and immunolocalization of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) to show that the sterile spikelet assimilates carbon, which is translocated to the largely heterotrophic SS. The awn shows no evidence of photosynthesis. These results apply to distantly related species of Andropogoneae. Removal of sterile spikelets in sorghum significantly decreases seed weight (yield) by ∼9%. Thus, the sterile spikelet, but not the awn, affects yield in the cultivated species and fitness in the wild species.
Role of Surgical Embolectomy and ECMO in PE

Surgical pulmonary embolectomy (SPE) is increasingly being utilized in North America and abroad following the diagnosis of acute submassive and massive PE. With the recent development of SPE centers of excellence and institution-based protocols, survival has rapidly improved, in particular in the setting of cardiopulmonary bypass and venoarterial- extracorporeal membrane oxygenation (VA-ECMO). Randomized control trials are needed to further elucidate the benefits of a “VA-ECMO/surgery first” strategy compared to thrombolytic catheter-directed therapy and traditional anticoagulation medical management.
Seizing the Center: Vigilantes and Gangsters in Indonesian Historiography

This article intends to cast light on historical continuities between pre-colonial, colonial, and post-colonial organized violent crime in Indonesia and its connection to the country’s rulers. The core argument is that Indonesia and the polities which once existed in its territory have a long history of cooperation between the ruling elites and the criminal world. The early-modern era bandits, called jago, and the modern gangsters, known as preman, arguably represented an important pillar of the power of political regimes in Java from the pre-colonial Javanese kingdoms to the Netherlands East Indies’ colonial state to Soeharto’s New Order. In post-Soeharto Indonesia, political liberation combined with the impact of jihadist Islam(ism) has created conditions in which a number of leather-clad gangsters have turned into vigilante defenders of Islam, who are sometimes co-opted by influential interest groups and sometimes sent back to the political periphery after falling out of favor. While the primary objective of this paper is to analyze the issue of oscillation between incorporation, co-optation, and utilization of criminals and radical Islamic groupings by the powerful, on the one hand, and their elimination, on the other, the paper also looks into how Indonesian historiography has depicted these influential bandits/gangsters/vigilantes and how historiographical sources tend to legitimize them to create an authoritative nationalist narrative.
Rare complication of four extremity compartment syndrome requiring fasciotomy from influenza A viral myositis.

Influenza A and B commonly cause benign respiratory disease in humans, but can cause more severe illness in high-risk populations. We report an unusual case of a previously healthy adult patient who presented with myositis and severe rhabdomyolysis secondary to influenza A infection that resulted in atraumatic compartment syndrome of all four extremities, each requiring emergent fasciotomy. The patient was subsequently managed with delayed primary closure and skin grafting in the operating room. Prompt recognition of this rare complication by the team resulted in no limb amputations. On his first follow-up appointment, 1 month after discharge, he had regained full functionality in both his hands and his feet were both close to 50% of baseline and improving with physical therapy.
Current Concepts Review: Common Peroneal Nerve Palsy After Knee Dislocations:

Dislocation of the native knee represents a challenging injury, further complicated by the high rate of concurrent injury to the common peroneal nerve (CPN). Initial management of this injury requires a thorough neurovascular examination, given the prevalence of popliteal artery injury and limb-threatening ischemia. Further management of a knee dislocation with associated CPN palsy requires coordinated care involving the sports surgeon for ligamentous knee reconstruction and the peripheral nerve surgeon for staged or concurrent peroneal nerve decompression and/or reconstruction. Finally, the foot and ankle surgeon is often required to manage a foot drop with a distal tendon transfer to restore foot dorsiflexion. For instance, the Bridle Procedure-a modification of the anterior transfer of the posterior tibialis muscle, under the extensor retinaculum, with tri-tendon anastomosis to the anterior tibial and peroneus longus tendons at the anterior ankle-can successfully return patients to brace-free ambulation and athletic function following CPN palsy. Cross-discipline coordination and collaboration is essential to ensure appropriate timing of operative interventions and ensure maintenance of passive dorsiflexion prior to tendon transfer.
Correlation between hemorrhage risk prediction score and severe maternal morbidity.

BACKGROUND Obstetrical hemorrhage is a leading cause of severe maternal morbidity, a key indicator of a nation's healthcare delivery system and often associated with a high rate of preventability. Limited data suggest that a patient's hemorrhage risk score may be associated with risk for maternal morbidity such as severe hemorrhage, intensive care unit admission, or transfusion. Little is known regarding the relationship between hemorrhage risk score and nontransfusion-related morbidity. OBJECTIVE We sought to evaluate the association between a patient's California Maternal Quality Care Collaborative admission hemorrhage risk score and severe maternal morbidity. STUDY DESIGN This was a retrospective cohort of delivery admissions from 2018 to 2019 in a single healthcare network. Admission risk scores were assigned to each patient using the California Maternal Quality Care Collaborative criteria. Rates of transfusion- and nontransfusion-associated severe maternal morbidity were compared across low-, medium-, and high-risk strata. We defined severe maternal morbidity as the presence of any International Classification of Diseases diagnosis or procedure codes outlined by the Centers for Disease Control and Prevention, need for intensive care unit admission, or prolonged postpartum hospital length of stay. A multivariable logistic regression was used to assess the association between hemorrhage risk score and severe maternal morbidity. RESULTS In the overall cohort, severe maternal morbidity occurred in 2.4% (n=517) of all deliveries. Excluding cases requiring transfusion, 0.6% (n=131) of cases still had a severe maternal morbidity event. The incidence of severe maternal morbidity was 1.6% (n=264) in patients categorized as low risk for hemorrhage compared with 2.5% (n=118) and 13.6% (n=135) in patients who were categorized as medium or high risk for hemorrhage, respectively (P CONCLUSION In addition to predicting the risk for obstetrical hemorrhage and transfusion, our findings indicate that the California Maternal Quality Care Collaborative admission hemorrhage risk tool predicts risk for transfusion- and nontransfusion-associated severe maternal morbidity. Our findings imply that despite awareness and the identification of patients at high risk for obstetrical hemorrhage on admission, significant hemorrhage-associated morbidity persisted. Our data indicate that the identification of risk alone may be insufficient to reduce morbidity and imply that further work is needed to investigate and implement new practices in response to a patient's score stratum.
Exercise and upper respiratory tract infection

The relationship between physical and psychologic stress, immune function, and upper respiratory tract infection (URTI) is reviewed in this article. There are relatively few studies that have explored this relationship. Of seven studies currently published, five are epidemiologic in design (two prospective and three retrospective), and only two used a randomized, controlled experimental design. In general, these studies support the concept that, although risk of URTI may decrease below that of a sedentary individual when engaging in moderate exercise training, risk may be elevated during periods of excessive amounts of exercise. Risk of URTI in athletes appears to be especially high during the 1‐ or 2‐week period following marathon‐type race events. Among runners varying widely in training habit, the risk for URTI is slightly elevated for those runners with the highest training mileage only when several confounding factors are controlled for. This interpretation is consistent with experimental evidence fr...
Anonymous Credentials: Opportunities and Challenges

In an anonymous (or private) credential system as put forth by Chaum in 1985, a user is known to different organizations by pseudonyms only. The system allows the user to obtain a credential from one organization and then later show such credentials to another organizations without that transactions are linkable. The area of privacy enhancing cryptography protocols and, in particular, anonymous credential systems have recently gained considerable momentum in research and indeed many substantial contributions have been made in last few years. At the same time, the interest in applying such systems in the real world has grown. Despite of this, the area is still relatively young and there are still many open research challenges to overcome. In this talk, we will review the state of the art in anonymous credential systems. We will then discuss their applications including privacy enhancing identity management (www.prime-project.eu.org) and anonymous attestation. Finally, we will discuss research directions and challenges.
Terahertz Radiation from Electro-Optic Crystals

With illumination by femtosecond laser pulses at an oblique incident angle, a semiconductor sample emits subpicosecond submillimeter-wave radiation1. This phenomenon was interpreted as radiation from accelerated photocarriers in the surface depletion field1 and the dependence of the radiation on crystal rotation symmetry was explained as strong evidence of X (3) related optical rectification2. More recently, quantum well structures have been used to limit the carrier transport. This allows examination of the mechanism of optical rectification as well as the study of electron coherent oscillations in a double-well potential3. To distinguish between the contribution from carrier transport and from optical rectification is crucial for a physical understanding of the origin of the radiation, as well as for realizing an intense THz source application.
Phase I Trial of Carboplatin and Gemcitabine Chemotherapy and Stereotactic Ablative Radiosurgery for the Palliative Treatment of Persistent or Recurrent Gynecologic Cancer

Background: We conducted a phase I trial to determine the safety of systemic chemotherapy prior to abdominopelvic robotic stereotactic ablative radiotherapy (SABR) in women with persistent or recurrent gynecologic cancers. Methods: Patients were assigned to dose-finding cohorts of day-1 carboplatin (AUC 2 or 4) and gemcitabine (600 or 800 mg/m2) followed by day-2 to day-4 Cyberknife SABR (8Gy X 3 consecutive daily doses). Toxicities were graded prospectively by common terminology criteria for adverse events, version 4.0. SABR target and best overall treatment responses were recorded according to response evaluation criteria in solid tumors, version 1.1. Findings: The maximum tolerated dose of chemotherapy preceding SABR was carboplatin AUC 4 and gemcitabine 600 mg/m2. One patient experienced manageable, dose-limiting grade 4 neutropenia, grade 4 hypokalemia, and grade 3 nausea attributed to study treatment. One patient had a late grade 3 rectovaginal fistula 16 months after trial therapy. Among 28 SABR targets, 22 (79%) showed a partial response and six (21%) remained stable. Interpretation: Systemic chemotherapy may be given safely prior to abdominopelvic robotic SABR with further investigation warranted. Funding: National Institutes of Health grant P30 CA43703
A current reconstruction algorithm for three-phase inverters using integrated current sensors in the low-side switches

Power semiconductor switches that include integrated pilot current sensors create opportunities to eliminate external current sensors in three-phase inverter applications. Each of the three conventional low-side power switches in a three-phase inverter can be replaced by one of these special devices that is designed to provide a sensing level current that accurately mirrors its total forward current. Recognizing that the output current in each phase flows through the low-side switch for only a portion of the fundamental cycle, a technique has been developed to reconstruct the full phase current waveforms for R-L loads using only the incomplete phase current measurements. The performance characteristics of the proposed current reconstruction technique are experimentally verified, including demonstration of a closed-loop three-phase current regulator using the reconstructed current feedback from the integrated pilot current sensors.
Concomitant characterization of behavioral and striatal neurotransmitter response to amphetamine using in vivo microdialysis

The temporal and dose-related behavioral and striatal monoamine response to amphetamine (AMPH) was examined using in vivo microdialysis in freely moving rats. Extracellular dopamine (DA), serotonin (5-HT), and their metabolites were monitored concomitant with detailed characterization of the locomotor and stereotypy profiles. Consistent with previous results, AMPH (0.5–5.0 mg/kg) induced a rapid dose- dependent increase in DA concentration and decrease in the concentrations of the DA metabolites, DOPAC and HVA. DA and its metabolites exhibited contrasting temporal and dose-related patterns, suggesting that the decline in DA metabolites is functionally dissociated from the AMPH-enhanced DA release. In addition, AMPH at doses of 2.0 mg/kg and greater significantly increased extracellular concentrations of 5-HT, which, in contrast to the changes in dopamine, persisted for only 20–40 min. Comparisons of concentrations of DA and 5- HT for individual animals revealed significant correlations both during baseline and drug response, suggesting a possible functional interdependence between dopaminergic and serotonergic activity in striatum. Dose-response comparisons revealed a significant relationship between AMPH-induced increases in behavioral perseveration and the magnitude and duration of the DA release. However, the temporal patterns of the neurotransmitter response and individual components of stereotypy were not parallel, suggesting that the presence of stereotypies is not associated simply with quantitative differences in striatal DA release. By contrast, some features of the behavioral response were significantly correlated with AMPH-induced changes in striatal 5-HT concentrations. Our results suggest that the behavioral response to AMPH may be influenced by the interaction between levels of DA and 5-HT release, as well as by the state of their respective receptors.
Integrated EMG study of the medial and lateral heads of the gastrocnemius during isometric plantar flexion with varying cuff weight loads

Both heads of the gastrocnemius muscle contribute to ankle plantar flexion. This study utilized integrated electromyography to investigate whether the percent electrical activity contributed by each head remained constant or changed during isometric contractions at five different resistance levels. Fifty healthy volunteers ranging in age from 19 to 34 years, with no history of musculoskeletal or neuromuscular disorders involving the right lower extremity, were studied. All tasks were performed in the prone position, knee in extension, with the leg and foot in neutral with respect to rotation. Motor points of the medial head and lateral head were identified and surface electrodes were placed just distal to them. The subjects maintained 20° of plantar flexion under five conditions: a maximal isometric plantar flexion contraction (one trial only), and with a 5-, 10-, 15- and 20-lb cuff weight attached to the right foot (three trials each). EMG recordings, 8 s in length, were taken during the isometric contractions. Integrated EMGs were averaged for each cuff weight and the resulting values used in the analysis. A repeated measures ANOV A was performed and a significance level of p ~ 0.05 was used to determine statistical significance. As weight increased, the absolute value of the integrated EMG recorded over both muscles increased, but the percent contributed by each head remained essentially equal (50%) within the four submaximal loads tested. However, for the maximal isometric contraction, the medial head contributed a significantly higher percentage of the total integrated EMG (58%). Therefore, in the open-chain activity described, the two heads of the gastrocnemius demonstrate similar neural drive at submaximal levels of contraction, but this changes as maximum isometric levels are reached. © 1998 Elsevier Science Ireland Ltd. All rights reserved.
Winds from the Atlanta /34 deg N, 84 deg W/ radio meteor wind facility

A brief description of the Georgia Tech radio meteor wind facility is followed by a tabular presentation and discussion of winds measured over Atlanta (34 deg N, 84 deg W) for the first three intervals of the URSI/IAGA Cooperative Tidal Observations Program (CTOP). The pervailing zonal wind measured during August 1974, being easterly, is significantly different from that measured during October 1975 and January 1976, and is not typical of winds measured in August 1975 and August 1976, when westerlies predominated. The complicated tidal picture is detailed, but is not easily summarized.
Characterization of Glass-Reinforced Composites for Cryogenic Applications

The reaction of a composite system to a service load is a complex function of the physical and mechanical properties of its components (matrix and reinforcement); the relative directionality of the applied loads versus the geometry of the reinforcement (anisotropy effect); the magnitude of the applied loads, and the rate at which they are introduced (viscoelasticity effect). Although all these parameters may not be important in a particular design with a selected reinforcement and simple loading, understanding that these effects exist and being prepared to include them in design criteria is critical for developing cost-effective high performance composite parts. As composite systems are introduced as secondary and primary structures for cryogenic applications, characterization of the interaction of stress and low temperatures on the performance of these systems is also necessary.
Regional parameter estimation for the unified land model

[1] We describe a regional parameter estimation scheme for the unified land model developed using a set of 220 river basins (102–104 km2) distributed across the conterminous United States. We evaluate predictive relationships between geographically varying catchment features and the model's soil parameters using principal components analysis. In addition to commonly used catchment descriptors (meteorological, geomorphic, and land-cover characteristics), we used satellite remote-sensing products and the United States Geologic Survey Geospatial Attributes of Gages for Evaluating Streamflow (GAGES-II) database. In a series of regionalization experiments, we contrast the more conventional procedure of using locally optimized parameters as predictands, with an approach that searches for zonally representative parameter values, using limited additional simulations. Parameters were evaluated through hydrologic model simulations in which daily flows were compared with observations over a 20 year period. We show that the penalty in streamflow prediction skill for using zonal parameters at a given basin (i.e., locally) is comparatively smaller than the penalty for using local parameters zonally. Regionalizations using zonal parameters and local catchment descriptors had the best model performance for both training and validation periods. Finally, we investigate the potential for transferring parameters globally by repeating the regionalization using only catchment attributes derived from globally available data and show that for the United States, model performance is only slightly worse than when U.S.-specific data area used.
Defects in polynucleotide phosphorylase impairs virulence in Escherichia coli O157:H7

Polynucleotide phosphorylase (PNPase) is reported to regulate virulence in Salmonella, Yersinia sp. and Campylobacter jejuni, yet its role in Escherichia coli O157:H7 has not been investigated. To gain insights into its roles in E. coli O157:H7 virulence, pnp deletion mutants were generated and the major virulence factors were compared to their parental wild type strains. Deletion of pnp in E. coli O157:H7 dramatically decreased stx2 mRNA expression and Stx2 protein production, and impaired lambdoid prophage activation in E. coli O157:H7. Quantitative PCR further confirmed that the Stx2 phage lytic growth was repressed by pnp deletion. Consistent with reduced Stx2 production and Stx2 phage activation, the transcriptional levels of genes involved in phage lysis and replication were down-regulated. In addition, disruption of pnp in E. coli O157:H7 decreased its adhesion to intestinal epithelial cells as well as cattle colonic explant tissues. On the other hand, PNPase inactivation in E. coli O157:H7 enhanced Tir protein content and the transcription of type three secretion system components, including genes encoding intimin, Tir, and EspB as well as locus of enterocyte and effacement positive regulator, Ler. Collectively, data indicate that PNPase has pleiotropic effects on the virulence of E. coli O157:H7.
Experimental Demonstration Of A Holographic Memory With A Surface Density Of 100 bits/spl um/m/sup 2/

The next generation compact disc due in early 1997, the Digital-Video-Disc (DVD), will have a capacity of ~6 Gbytes per layer, for a maximum planned capacity of ~20 Gbytes per double-sided disk with two layers on each side. That translates to a surface density of approximately 20 bits/(µm^2) for the four-layered DVD disk. In order for holographic three-dimensional disks to be competitive, we must demonstrate a much higher surface density than the most advanced DVD.
On the Stress Concentration in the Matrix Around the Fibers in Laminae

This paper is concerned with reporting of the effect of fiber volume fraction on the results of stress concentration in the matrix at the fiber-matrix interface in laminae. It adds to the results published in Reference [1] which may be considered reasonable only for very low fiber volume fractions. Four different types of fibers in epoxy matrix are considered to examine the effect of variation of the ratio of modulus of elasticity of the fiber in epoxy.
Optimization of instruction fetch mechanisms for high issue rates

Recent superscalar processors issue four instructions per cycle. These processors are also powered by highly-parallel superscalar cores. The potential performance can only be exploited when fed by high instruction bandwidth. This task is the responsibility of the instruction fetch unit. Accurate branch prediction and low I-cache miss ratios are essential for the efficient operation of the fetch unit. Several studies on cache design and branch prediction address this problem. However, these techniques are not sufficient. Even in the presence of efficient cache designs and branch prediction, the fetch unit must continuously extract multiple, non-sequential instructions from the instruction cache, realign these in the proper order, and supply them to the decoder. This paper explores solutions to this problem and presents several schemes with varying degrees of performance and cost. The most-general scheme, the collapsing buffer, achieves near-perfect performance and consistently aligns instructions in excess of 90% of the time, over a wide range of issue rates. The performance boost provided by compiler optimization techniques is also investigated. Results show that compiler optimization can significantly enhance performance across all schemes. The collapsing buffer supplemented by compiler techniques remains the best-performing mechanism. The paper closes with recommendations and suggestions for future.
Certification of standard reference material (SRM) 1941a, organics in marine sediment

SRM 1941a, Organics in Marine Sediment, has been recently issued with certified concentrations for 23 polycyclic aromatic hydrocarbons, 21 polychlorinated biphenyl congeners, 6 chlorinated pesticides, and sulfur. Noncertified concentrations have been also reported for additional PAHs, PCB congeners, and chlorinated pesticides and for percent total organic carbon (TOC), aliphatic hydrocarbons, and trace elements. SRM 1941a is the most extensively characterized natural matrix SRM issued by the National Institute of Standards and Technology (NIST).
Identifying delamination in an experimental composite UAV wing subject to ambient gust loading

Vibration-based structural health monitoring has largely considered applied excitations as the primary means of inducing structural vibration. Here we consider how ambient vibrations might be used to assess the level of damage in a composite UAV wing. The wing consists of a foam core and a carbon fiber skin. We subject the wing to various amounts of impact damage in order to cause internal delaminations. The wing is then excited using a gust loading waveform in an effort to simulate the forcing the wing is expected to see in flight. We then use a probabilistic description of the structure's dynamics to assess the level of damage-induced nonlinearity in the wing. The approach is capable of making the diagnosis in the absence of a representative baseline data set from the "healthy" wing.
Contribution of titin and extracellular matrix to passive pressure and measurement of sarcomere length in the mouse left ventricle

It remains to be established to what degree titin and the extracellular matrix (ECM) contribute to passive pressure in the left ventricle (LV). Thus, we aimed to elucidate the contribution of major molecular determinants of passive pressure in the normal mouse LV. Furthermore, we determined the working sarcomere length (SL) range of the LV to bridge our findings to earlier work in skinned muscle fibers. We utilized Frank-Starling type protocols to obtain diastolic pressure-volume relationships (PVR) in Langendorff perfused isolated LVs. To quantify the molecular contribution of titin and ECM, we innovated on methods of fiber mechanics to chemically permeabilize intact LVs and measure a fully passive PVR. To differentially dissect the contributions of the ECM and titin, we utilized myofilament extraction techniques in permeabilized LVs, measuring passive PVRs at each stage in the protocol. Myofilament extraction suggests that titin contributes ~80% of passive pressures in the heart. Langendorff perfusion was also used to chemically fix passive and BaCl(2) activated hearts at specific volumes to determine that the maximal working SL range of the midwall LV fibers is approximately 1.8-2.2 μm. A model of the passive SL-volume relationship was then used to estimate the pressure-SL relationships, indicating that the ECM contribution does not exceed titin's contribution until large volumes with SLs >~2.2 μm. In conclusion, within physiological volumes, titin is the dominant contributor to LV passive pressure, and ECM-based pressures dominate at larger volumes.