cssi/SciSciGPT-SciSciNet huggingface dataset:
Chlorophyte aspartyl aminopeptidases: Ancient origins, expanded families, new locations, and secondary functions

M18 aspartyl aminopeptidases (DAPs) are well characterized in microbes and animals with likely functions in peptide processing and vesicle trafficking. In contrast, there is a dearth of knowledge on plant aminopeptidases with a preference for proteins and peptides with N-terminal acidic residues. During evolution of the Plantae, there was an expansion and diversification of the M18 DAPs. After divergence of the ancestral green algae from red and glaucophyte algae, a duplication yielded the DAP1 and DAP2 lineages. Subsequently DAP1 genes were lost in chlorophyte algae. A duplication of DAP2-related genes occurred early in green plant evolution. DAP2 genes were retained in land plants and picoeukaryotic algae and lost in green algae. In contrast, DAP2-like genes persisted in picoeukaryotic and green algae, while this lineage was lost in land plants. Consistent with this evolutionary path, Arabidopsis thaliana has two DAP gene lineages (AtDAP1 and AtDAP2). Similar to animal and yeast DAPs, AtDAP1 is localized to the cytosol or vacuole; while AtDAP2 harbors an N-terminal transit peptide and is chloroplast localized. His6-DAP1 and His6-DAP2 expressed in Escherichia coli were enzymatically active and dodecameric with masses exceeding 600 kDa. His6-DAP1 and His6-DAP2 preferentially hydrolyzed Asp-p-nitroanilide and Glu-p-nitroanilide. AtDAPs are highly conserved metallopeptidases activated by MnCl2 and inhibited by ZnCl2 and divalent ion chelators. The protease inhibitor PMSF inhibited and DTT stimulated both His6-DAP1 and His6-DAP2 activities suggesting a role for thiols in the AtDAP catalytic mechanism. The enzymes had distinct pH and temperature optima, as well as distinct kinetic parameters. Both enzymes had high catalytic efficiencies (kcat/Km) exceeding 1.0 x 107 M-1 sec-1. Using established molecular chaperone assays, AtDAP1 and AtDAP2 prevented thermal denaturation. AtDAP1 also prevented protein aggregation and promoted protein refolding. Collectively, these data indicate that plant DAPs have a complex evolutionary history and have evolved new biochemical features that may enable their role in vivo.
Introducing the new bacterial branch of the RNase A superfamily.

Bovine pancreatic ribonuclease (RNase A) is the founding member of the RNase A superfamily. Members of this superfamily of ribonucleases have high sequence diversity, but possess a similar structural fold, together with a conserved His-Lys-His catalytic triad and structural disulfide bonds. Until recently, RNase A proteins had exclusively been identified in eukaryotes within vertebrae. Here, we discuss the discovery by Batot et al. of a bacterial RNase A superfamily member, CdiA-CTYkris: a toxin that belongs to an inter-bacterial competition system from Yersinia kristensenii. CdiA-CTYkris exhibits the same structural fold as conventional RNase A family members and displays in vitro and in vivo ribonuclease activity. However, CdiA-CTYkris shares little to no sequence similarity with RNase A, and lacks the conserved disulfide bonds and catalytic triad of RNase A. Interestingly, the CdiA-CTYkris active site more closely resembles the active site composition of various eukaryotic endonucleases. Despite lacking sequence similarity to eukaryotic RNase A family members, CdiA-CTYkris does share high sequence similarity with numerous Gram-negative and Gram-positive bacterial proteins/domains. Nearly all of these bacterial homologs are toxins associated with virulence and bacterial competition, suggesting that the RNase A superfamily has a distinct bacterial subfamily branch, which likely arose by way of convergent evolution. Finally, RNase A interacts directly with the immunity protein of CdiA-CTYkris, thus the cognate immunity protein for the bacterial RNase A member could be engineered as a new eukaryotic RNase A inhibitor.
Finitely convergent learning programs for the separation of sets of shaded figures

A description is given of a non-parametric training program for constructing a non-linear functional which separates two disjoint sets G and P on the surface of the unit sphere in an arbitrary ?2-space. It is shown that if G and P are separable in a certain general sense, then the program is finitely convergent.
Speaking ‘out of turn’: Epistemics in action in other-initiated repair

This article provides an empirical demonstration of the saliency of epistemics to two core conversational organizations, turn-taking and repair. To that end, I examine cases in which a participant ...
Preparation of Pure Populations of Amyloid β-Protein Oligomers of Defined Size

Protein and peptide oligomers are thought to play important roles in the pathogenesis of a number of neurodegenerative diseases. For this reason, considerable effort has been devoted to understanding the oligomerization process and to determining structure-activity relationships among the many types of oligomers that have been described. We discuss here a method for producing pure populations of amyloid β-protein (Aβ) of specific sizes using the most pathologic form of the peptide, Aβ42. This work was necessitated because Aβ oligomerization produces oligomers of many different sizes that are non-covalently associated, which means ﻿that dissociation or further assembly may occur. These characteristics preclude rigorous structure-activity determinations. In studies of Aβ40, we have used the method of photo-induced cross-linking of unmodified proteins (PICUP) to produce zero-length carbon-carbon bonds among the monomers comprising each oligomer, thus stabilizing the oligomers. We then isolated pure populations of oligomers by fractionating the oligomers by size using SDS-PAGE and then extracting each population from the stained gel bands. Although this procedure worked well with the shorter Aβ40 peptide, we found that a significant percentage of Aβ42 oligomers had not been stabilized. Here, we discuss a new method capable of yielding stable Aβ42 oligomers of sizes from dimer through dodecamer.
HGF/c-MET Signaling in Advanced Cancers

Papillary renal carcinoma (RCCP) is histologically and genetically distinct from other forms of inherited renal carcinoma (e.g., von Hippel–Lindau disease, which is caused by inactivation of the VHL gene –( see Chapter 6). RCCP genes map to several loci; one of each on 7q31.1-q34 encodes the c-Met oncoprotein (Schmidt et al. 1997). In the original publication, missense mutations in the tyrosine kinase domain of the MET gene were found both in the germlines of affected patients and in a subset of sporadic papillary renal carcinomas. Additionally, tumors from RCCP patients commonly show trisomy of chromosome 7 harboring non-random duplication of the mutant MET allele (Zhuang et al. 1998).
Complexation of the Mycotoxin Cyclopiazonic Acid with Lanthanides Yields Luminescent Products

Cycopiazonic acid (CPA) is a neurotoxin that acts through inhibition of the sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA). CPA blocks the calcium access channel of the enzyme. The inhibition may involve the binding of CPA with a divalent cation such as Mg2+. The potential for CPA to act as a chelator also has implications for methods to detect this toxin. Certain of the lanthanide metals undergo a dramatic increase in luminescence upon coordination with small molecules that can transfer excitation energy to the metal. This report is the first to describe the coordination of CPA with lanthanide metals, resulting in a substantial enhancement of their luminescence. The luminescence expressed was dependent upon the type of lanthanide, its concentration, and the environment (solvent, water content, pH). Based upon the phenomenon, a competitive assay was also developed wherein terbium (Tb3+) and a series of metal cations competed for binding with CPA. With increasing cation concentration, the luminescence of the CPA/Tb3+ complex was inhibited. The chlorides of ten metals were tested. Inhibition was best with Cu2+, followed by Co2+, Al3+, Fe3+, Mn2+, Au3+, Mg2+, and Ca2+. Two cations in oxidation state one (Na+, K+) did not inhibit the interaction significantly. The interaction of CPA with lanthanides provides a novel recognition assay for this toxin. It also provides a novel way to probe the binding of CPA to metals, giving insights into CPA’s mechanism of action.
Durability predictions of adhesively bonded composite structures using accelerated characterization methods

The utilization of adhesive bonding for composite structures is briefly assessed. The need for a method to determine damage initiation and propagation for such joints is outlined. Methods currently in use to analyze both adhesive joints and fiber reinforced plastics is mentioned and it is indicated that all methods require the input of the mechanical properties of the polymeric adhesive and composite matrix material. The mechanical properties of polymers are indicated to be viscoelastic and sensitive to environmental effects. A method to analytically characterize environmentally dependent linear and nonlinear viscoelastic properties is given. It is indicated that the methodology can be used to extrapolate short term data to long term design lifetimes. That is, the method can be used for long term durability predictions.
Intermediate Diabetes Outcomes in Patients Managed by Physicians, Nurse Practitioners, or Physician Assistants: A Cohort Study

Background Primary care provided by nurse practitioners (NPs) and physician assistants (PAs) has been proposed as a solution to expected workforce shortages. Objective To examine potential differences in intermediate diabetes outcomes among patients of physician, NP, and PA primary care providers (PCPs). Design Cohort study using data from the U.S. Department of Veterans Affairs (VA) electronic health record. Setting 568 VA primary care facilities. Patients 368 481 adult patients with diabetes treated pharmaceutically. Measurements The relationship between the profession of the PCP (the provider the patient visited most often in 2012) and both continuous and dichotomous control of hemoglobin A1c (HbA1c), systolic blood pressure (SBP), and low-density lipoprotein cholesterol (LDL-C) was examined on the basis of the mean of measurements in 2013. Inverse probability of PCP type was used to balance cohort characteristics. Hierarchical linear mixed models and logistic regression models were used to analyze continuous and dichotomous outcomes, respectively. Results The PCPs were physicians (n = 3487), NPs (n = 1445), and PAs (n = 443) for 74.9%, 18.2%, and 6.9% of patients, respectively. The difference in HbA1c values compared with physicians was -0.05% (95% CI, -0.07% to -0.02%) for NPs and 0.01% (CI, -0.02% to 0.04%) for PAs. For SBP, the difference was -0.08 mm Hg (CI, -0.34 to 0.18 mm Hg) for NPs and 0.02 mm Hg (CI, -0.42 to 0.38 mm Hg) for PAs. For LDL-C, the difference was 0.01 mmol/L (CI, 0.00 to 0.03 mmol/L) (0.57 mg/dL [CI, 0.03 to 1.11 mg/dL]) for NPs and 0.03 mmol/L (CI, 0.01 to 0.05 mmol/L) (1.08 mg/dL [CI, 0.25 to 1.91 mg/dL]) for PAs. None of these differences were clinically significant. Limitation Most VA patients are men who receive treatment in a staff-model health care system. Conclusion No clinically significant variation was found among the 3 PCP types with regard to diabetes outcomes, suggesting that similar chronic illness outcomes may be achieved by physicians, NPs, and PAs. Primary funding source VA Health Services Research and Development.
Drugs, Money, and Secret Handshakes: The Unstoppable Growth of Prescription Drug Prices

In the warped world of prescription drug pricing, generic drugs can cost more than branded ones, old drugs can be relaunched at astronomical prices, and low-cost options are shut out of the market. In Drugs, Money and Secret Handshakes, Robin Feldman shines a light into the dark corners of the pharmaceutical industry to expose a web of shadowy deals in which higher-priced drugs receive favorable treatment and patients are channeled toward the most expensive medicines. At the center of this web are the highly secretive middle players who establish coverage levels for patients and negotiate with drug companies. By offering lucrative payments to these middle players (as well as to doctors and hospitals), drug companies ensure that inexpensive drugs never gain traction. This system of perverse incentives has delivered the kind of exorbitant drug prices - and profits - that everyone loves except for those who pay the bills.
Rectal Stump Perforation Stump While Passing an End-to-End Anastomotic Stapler

Perforation of the rectal stump during end-to-end anastomosis should be prevented. In case of perforation, repair approach depends on the amount of disruption and the residual length of the rectum. Diverting stoma should be considered in all cases.
The edTPA and Physical Education Teacher Education: Working in Tandem to Prepare Successful Teachers.

Very few articles, chapters or professional presentations exist that are devoted to implementing the Teacher Performance Assessment (edTPA) within physical education teacher education (PETE) progra...
Features of mechanical behavior of EV battery modules under high deformation rate

Abstract We report on changes in material behavior of electric vehicle (EV) Li-ion battery cell modules when the loading speed increases from quasi-static to high speed (close to 1 m/s). A series of out-of-plane indentation experiments were performed on stacks of pouch cells placed in the specially designed enclosure to represent conditions in battery modules. Over one hundred of large format automotive pouch cells were tested under displacement rates differing by orders of magnitude. The details of internal failure were studied by X-ray tomography (XCT). We observe a shift in the force–displacement response from a parabolic behavior characteristic of particulate materials under compression to the response typical of fully dense materials with yield point. This shift is associated with dynamic effects in active materials which result in deep propagation of damage into the battery module, despite the fact that the internal short circuit is triggered when the displacement of the indenter is one half of that under the slow displacement rate.
Location Multiplicative Error Models with Quasi Maximum Likelihood Estimation

Motivated by improving the fitting of non‐negative financial time series, we extend the multiplicative error model and study the semi‐parametric estimation. We first introduce a location parameter and use the sample minimum to a truncate data set. In the case that there is a non‐trivial proportion of zeros in the truncated data, we adopt a zero‐augmented mixture distribution for the innovation terms. For both cases, we propose quasi maximum likelihood estimation for the multiplicative coefficients and establish asymptotic results. We conduct large simulation studies to demonstrate substantial estimation errors with misspecified models, and confirm the asymptotic properties. Moreover, we present an empirical study to illustrate the fitting improvement.
An Osteological Perspective on Prehistoric Warfare

Identifying and measuring intergroup relations represent significant, but intractable, problems for researchers dealing with prehistoric peoples. Human skeletons hold a great potential for providing otherwise unattainable information about interactions among ancient societies, including antagonisms that led to outright warfare. As used here for prehistoric horizons, warfare refers to purposeful violence calculated to advance the ambitions of separate political factions, regardless of who was involved, the regularity of fighting, the numbers of participants, or specific combat tactics. Despite the rather obvious connection between skeletons and combat casualties, osteological analyses have made few contributions to the study of conflict among prehistoric peoples (for a well-known exception see Wendorf [1968]).
CHAPTER 18 – NEUROCHEMICAL AND NEUROPHARMACOLOGICAL ASPECTS OF HISTAMINE RECEPTORS

Histamine H1 and H2 receptors have been identified in the mammalian central nervous system. Both receptor subtypes have been indirectly characterized by a variety of receptor-mediated biological assays and directly through the utilization of radioligand binding techniques. Two types of psychotherapeutic agents, the antidepressants and neuroleptics, are potent inhibitors of H1 and H2 receptors. However, most compounds tested have a higher affinity for H1 receptors. Like many other neurotransmitter receptors, H1 receptor function can be regulated by guanine nucleotides, various ions, and by the degree of agonist stimulation.
A Water-Based Proof of the Cauchy–Schwarz Inequality

The standard proof of the inequality of the title may appear a bit dry, and so I offer one that uses water. Consider n cylindrical cans with different cross-sectional areas ak that are connected by...
Oracle Database In-Memory on Active Data Guard: Real-time Analytics on a Standby Database

Oracle Database In-Memory (DBIM) provides orders of magnitude speedup for analytic queries with its highly compressed, transactionally consistent, memory-optimized Column Store. Customers can use Oracle DBIM for making real-time decisions by analyzing vast amounts of data at blazingly fast speeds. Active Data Guard (ADG) is Oracle’s comprehensive solution for high-availability and disaster recovery for the Oracle Database. Oracle ADG eliminates the high cost of idle redundancy by allowing reporting applications, ad-hoc queries and data extracts to be offloaded to the synchronized, physical Standby database replicated using Oracle ADG. In Oracle 12.2, we extended the DBIM advantage to Oracle ADG architecture. DBIM-on-ADG significantly boosts the performance of analytic, read-only workloads running on the physical Standby database, while the Primary database continues to process high-speed OLTP workloads. Customers can partition their data across the In-Memory Column Stores on the Primary and Standby databases based on access patterns, and reap the benefits of fault-tolerance as well as workload isolation without compromising on critical performance SLAs. In this paper, we explore and address the key challenges involved in building the DBIM-on-ADG infrastructure, including synchronized maintenance of the In-Memory Column Store on the Standby database, with high-speed OLTP activity continuously modifying data on the Primary database.
Lessons from Yalta: Imperatives for Post-Covid 19 Higher Education

The goal of this essay is to provide Higher Education institutions with suggestions for maintaining both economic viability and organizational credibility in a Post-Covid 19 environment. Three practical, yet important, objectives for both colleges and universities are identified in light of the pandemic and its aftermath. In particular, the essay targets administrative imperatives and stakeholder-oriented considerations for implementation.
A Sorting Network on Trees

Sorting networks are a class of parallel oblivious sorting algorithms. Not only do they have interesting theoretical properties but they can be fabricated. A sorting network is a sequence of parall...
Does it pay to ‘Be Like Mike’? Aspiratonal peer firms and relative performance evaluation

We examine the manner and extent to which firms evaluate performance relative to aspirational peer firms. Guided by the predictions of an agency model, we find that CEO compensation increases in the correlation between own and aspirational peer firm performances. In addition, we define and test conditions where aggregate peer performance, which has been the primary focus of prior relative performance evaluation studies of competitive peers, is expected to have an association with CEO compensation. These conditions are supported by our empirical results. Finally, we document that our results are more pronounced when the firm-peer relationship is one-way and the peer firm is in a different industry and therefore is more aspirational.
Resource Allocation Contests: Experimental Evidence

Many resource allocation contests have the property that individuals undertake costly actions to appropriate a potentially divisible resource. We design an experiment to compare individuals’ decisions across three resource allocation contests which are isomorphic under risk-neutrality. The results indicate that in aggregate the single-prize contest generates lower expenditures than either the proportional-prize or the multi-prize contest. Interestingly, while the aggregate results indicate similar behavior in the proportional-prize and multi-prize contests, individual level analysis indicates that the behavior in the single-prize contest is more similar to the behavior in the multi-prize contest than in the proportional-prize contest. We also elicit preferences toward risk, ambiguity and losses, and find that while such preferences cannot explain individual behavior in the proportional-prize contest, preferences with regard to losses are predictive of behavior in both the single-prize and multiple-prize contests. Therefore, it appears that loss aversion is correlated with behavior in the single-prize and multi-prize contests where losses are likely to occur, but not in the proportional-prize contest where losses are unlikely.
Telehealth Transition Assistance Program for Acute Spinal Cord Injury Caregivers: Protocol for a Mixed-Methods, Randomized Controlled Trial.

Background: While spinal cord injury (SCI) caregiving can be a rewarding experience, caregivers often experience reduced mental and physical health. Objective: This article describes the methodology of a study examining the efficacy of a newly developed telehealth Transition Assistance Program (TAP) for caregivers of individuals with acute SCI. Methods: A mixed-methods, randomized controlled trial is comparing TAP outcomes to that of a standard-of-care control. The study is recruiting for 48 months and incorporating both quantitative and qualitative outcome measures. Data are collected regarding barriers and facilitators to using the TAP, which might inform dissemination and implementation. Results: This study was funded by the Craig H. Neilsen Foundation in April 2017. It was approved by the institutional review boards at Virginia Commonwealth University and the Hunter Holmes McGuire Veterans Affairs Medical Center that same year. Participant recruitment and data collection began in 2018. Conclusions: This study is implementing and testing an SCI caregiver intervention unlike any created before, targeting a critical time period that, until now, other SCI caregiver interventions have overlooked. Research personnel intend to disseminate the intervention and study findings through the publication of manuscripts and presentations at conferences. If the current study shows improvements in caregiver or patient well-being, the TAP for SCI caregivers could become part of the standard of care for acute SCI. Trial Registration: ClinicalTrials.gov NCT03244098; https://www.clinicaltrials.gov/ct2/show/NCT03244098
Corp to Cloud: Google’s Virtual Desktops: How Google moved its virtual desktops to the cloud

Over one-fourth of Googlers use internal, data-center-hosted virtual desktops. This on-premises offering sits in the corporate network and allows users to develop code, access internal resources, and use GUI tools remotely from anywhere in the world. Among its most notable features, a virtual desktop instance can be sized according to the task at hand, has persistent user storage, and can be moved between corporate data centers to follow traveling Googlers. Until recently, our virtual desktops were hosted on commercially available hardware on Google’s corporate network using a homegrown open-source virtual cluster-management system called Ganeti. Today, this substantial and Google-critical workload runs on GCP (Google Compute Platform). This article discusses the reasons for the move to GCP, and how the migration was accomplished.
Yeast inorganic pyrophosphatase. VI. Studies on specificity and mechanism.

Abstract Analogs of PPi in which the bridge oxygen is replaced by imido, methylene, or α,ω-glycol linkages are not substrates for crystalline yeast inorganic pyrophosphatase. Apparent competitive inhibition of Mg2+-activated PPi hydrolysis is observed with imidodiphosphate and with the C1 and C2 members of the α,ω-glycol diphosphate series, methanediol diphosphate and 1,2-ethanediol diphosphate. Methylene diphosphonate, two of its C-substituted derivatives, and the C3 and C4 members of the α,ω-glycol diphosphate series are not inhibitory under the conditions employed, which are near optimal for PPi hydrolysis. Specificity for inhibitors is not markedly broader than specificity for substrate, and, like substrate specificity, is maximal in the presence of Mg2+ as activating ion. No evidence could be obtained for phosphoryl transfer to any acceptor other than water. Using 32PPi in a variety of conditions, several types of assays failed to detect formation of a phosphorylated enzyme intermediate in the reaction. The results are interpreted as favoring a concerted mechanism for this enzyme.
A General Approach for Controlling Transcription and Probing Epigenetic Mechanisms: Application to the Cd4 Locus

Synthetic regulatory proteins such as tetracycline (tet)-controlled transcription factors are potentially useful for repression as well as ectopic activation of endogenous genes and also for probing their regulatory mechanisms, which would offer a versatile genetic tool advantageous over conventional gene targeting methods. In this study, we provide evidence supporting this concept using Cd4 as a model. CD4 is expressed in double-positive and CD4 cells but irreversibly silenced in CD8 cells. The silencing is mediated by heterochromatin established during CD8 lineage development via transient action of the Cd4 silencer; once established, the heterochromatin becomes self-perpetuating independently of the Cd4 silencer. Using a tet-sensitive Cd4 allele harboring a removable Cd4 silencer, we found that a tet-controlled repressor recapitulated the phenotype of Cd4-deficient mice, inhibited Cd4 expression in a reversible and dose-dependent manner, and could surprisingly replace the Cd4 silencer to induce irreversible Cd4 silencing in CD8 cells, thus suggesting the Cd4 silencer is not the (only) determinant of heterochromatin formation. In contrast, a tet-controlled activator reversibly disrupted Cd4 silencing in CD8 cells. The Cd4 silencer impeded this disruption but was not essential for its reversal, which revealed a continuous role of the silencer in mature CD8 cells while exposing a remarkable intrinsic self-regenerative ability of heterochromatin after forced disruption. These data demonstrate an effective approach for gene manipulation and provide insights into the epigenetic Cd4 regulatory mechanisms that are otherwise difficult to obtain.
Beyond “Inherit It or Marry It”: Exploring How Women Engaged in Sustainable Agriculture Access Farmland

Despite an overall decrease in new farm operations, the number of women farm operators grew 30 percent between 2002 and 2007, with 300 percent growth since 1978. This research suggests, however, that opportunities for women have unfolded unevenly. We argue that women's opportunities to farm are affected by their social location and life course, suggesting that as their lives unfold across specific cultural and economic moments, different cohorts of women experience divergent opportunities to farm. Using in-depth interviews with women engaged in sustainable farming in the Inland Northwest, this article examines how women access farmland. Our findings suggest three methods for access: (1) access through the traditional means of marrying a male farmer and then carving out space for one's self as a farmer; (2) access later in life after a life-altering event like divorce and using personal financial means, such as retirement income or selling appreciated property; (3) access at a young age through the pooling of marital resources with a husband who works off the farm. Our research suggests that women's land access should not be presumed a progressive narrative and suggests the need for a more complex understanding of the challenges that women in agriculture face today despite their increased presence in farming.
The High Density Interiors of Neutron Stars

This talk reviews current understanding of the states of matter in the liquid interior of neutron stars — including nuclear matter, pion and kaon condensation, and normal and strange quark matter — and their effect on neutron star structure and dynamics. Learning about high density matter in the laboratory by means of ultrarelativistic heavy-ion collisions is also discussed.
On the tandem connection of differential encoding systems: The case of cascaded quantizers

A tandem differential pulse code modulation (DPCM) system structure is developed and the design problem formulated. In the simplified case of cascaded quantizers, the low-to-high and high-to-low bit rate tandems are examined and the performance limitations discussed, Finally the performance of tandem DPCM systems operating at various bit rates is evaluated by simulation.
Transplanting encephalomyocarditis virus-infected porcine islet cells reverses diabetes in recipient mice but also transmits the virus

Previous studies demonstrated that porcine encephalomyocarditis virus (EMCV) caused acute and persistent infection in the myocardium, central nervous system, and spleen of non-human primates (cynomolgus macaques); and it productively infected primary human cardiomyocytes, suggesting that the virus may pose a risk in pig-to-human transplantation. Recently, transplantation of myocardial and pancreatic tissues from acutely infected pigs transmitted the virus to recipient mice, resulting in acute fatal EMCV disease. Here, we examined whether porcine islet cells (PICs), which are under clinical trial for treatment of type I diabetes in humans, are susceptible to porcine EMCV, and whether EMCV-infected PICs could function in vivo to reverse diabetes. PICs were infected with EMCV in vitro for 5 h, and resulting insulin production compared with that produced by uninfected PICs. Subsequently, infected PICs were transplanted intra-abdominally or under the kidney capsule of C57BL/6 mice, and both virus transmission and PIC function analyzed. PICs were highly susceptible to porcine EMCV, resulting in a 1500-fold increase in production of infectious virus within 5 h of inoculation and cytolysis that destroyed up to 50% of cells within 96 h. However, as long as they were viable, infected PICs produced insulin at levels comparable with uninfected PICs. Intra-abdominal transplantation of 2000 PICs, infected with one plaque forming unit (pfu) per cell of porcine EMCV, into C57BL/6 mice transmitted the virus resulting in acute fatal EMCV disease characterized by hind limb paresis and paralysis and acute respiratory distress in 40% of recipient mice. More importantly, transplantation of 2500 EMCV-infected PICs under the kidney capsule of diabetic C57BL/6 mice (glucose level > or =350 mg/dl) reversed diabetes in 83% of recipient mice (glucose level < or =170 mg/dl); however these mice succumbed to acute EMCV disease transmitted by the xenograft 5 days after transplantation. EMCV infection does not appear to affect insulin production by PICs, but infected xenografts can transmit the virus to recipient animals, resulting in severe disease.
Bidding in a possibly common-value auction☆

Abstract We analyze a second-price auction with two bidders in which only one of the bidders is informed as to whether the object is valued commonly. We show that any equilibrium strategy of the bidder who is uninformed must be part of an equilibrium when both bidders instead know that the auction is not common value, regardless of the way in which the values are different. We derive sufficient conditions for equilibrium existence.
Dynamic Measurement of Two Dimensional Stress Components in Birefringent Materials

We adopt classical methods of photoelasticity and Mach–Zehnder interferometry in a combined arrangement in order to determine both principal stresses and their orientations simultaneously. The method is equally applicable to static and dynamic problems. In dynamic problems the measurement may be made with a high-speed photodetector at very high temporal resolution at a single point or a small array of points depending on the detector array and recording device; this eliminates the need for a high-speed photographic system, but more importantly the method described here provides complete, time-resolved evolution of all stress components. Examples of application of the method are demonstrated.
Distribution and Regulation of the Optic Nerve Head Tissue PO2

Abstract We investigated the distribution and regulation of the optic nerve head (ONH) tissue partial pressure of oxygen (PO 2 ) under various stimuli and the role of the nitric oxide in the ONH circulation. Tissue PO 2 was measured using double-barreled recess microelectrodes in the intact eyes of miniature pigs during normoxia, hyperoxia, hypoxia, variations of systemic blood pressure, and after inhibition of the endothelial nitric oxide synthesis by the administration of nitro-L-arginine. Measurements were performed in front of the ONH at intervascular and juxta-arteriolar areas and at a depth of 50 and 200 μm within the ONH at the center and the rim. During normoxia, PO 2 was heterogeneously distributed in the ONH, higher close to the arterioles than in intervascular areas. Hyperoxia induced a significant increase of juxta-arteriolar tissue PO 2 , while in intervascular areas no change was noticed. Hypoxia did not modify intervascular tissue PO 2 at 200 μm depth within the ONH. Variations of the systemic blood pressure did not induce any significant change in ONH tissue PO 2 . Similarly, no modification was noticed after the administration of nitro-L-arginine. There is a remarkable autoregulatory capacity of the ONH circulation that may compensate for parameters such as hyperoxia, hypoxia, and variations of the systemic blood pressure. Endothelially derived nitric oxide inhibition does not modify the ONH tissue PO 2 , probably because the tissue PO 2 is stabilized by compensatory regulation.
Orthogonal rotation to congruence

Two problems are considered. The first is that of rotating two factor solutions orthogonally to a position where corresponding factors are as similar as possible. A least-squares solution for transformations of the two factor matrices is developed. The second problem is that of rotating a factor matrix orthogonally to a specified target matrix. The solution to the second problem is related to the first. Applications are discussed.
Grid-search event location with non-Gaussian error models

Abstract This study employs an event location algorithm based on grid search to investigate the possibility of improving seismic event location accuracy by using non-Gaussian error models. The primary departure from the Gaussian error model that is considered is the explicit use of non-Gaussian probability distributions in defining optimal estimates of location parameters. Specifically, the class of generalized Gaussian distributions is considered, which leads to the minimization of L p norms of arrival time residuals for arbitrary p ≥ 1 . The generalized Gaussian error models are implemented both with fixed standard errors assigned to the data and with an iterative reweighting of the data on a station/phase basis. An implicit departure from a Gaussian model is also considered, namely, the use of a simple outlier rejection criterion for disassociating arrivals during the grid-search process. These various mechanisms were applied to the ISC phase picks for the IWREF reference events, and the resulting grid-search solutions were compared to the GT locations of the events as well as the ISC solutions. The results indicate that event mislocations resulting from the minimization of L p residual norms, with p near 1, are generally better than those resulting from the conventional L 2 norm minimization (Gaussian error assumption). However, this result did not always hold for mislocations in event depth. Further, outlier rejection and iterative reweighting, applied with L 2 minimization, performed nearly as well as L 1 minimization in some cases. The results of this study suggest that ISC can potentially improve its location capability with the use of global search methods and non-Gaussian error models. However, given the limitations of this study, further research, including the investigation of other statistical and optimization techniques not addressed here, is needed to assess this potential more completely.
The implications of differences between employer and worker employment/earnings reports for policy evaluation

Differences in administrative (UI) and survey (S) records on employment and earnings have substantial implications for assessing the impact of a variety of public interventions, such as welfare-to-work and employment training programs, and especially the state-oriented welfare reform legislation of 1996. We use data from the 1998 and 1999 waves of the Child Support Demonstration Evaluation (CSDE) Resident Parent Surveys to explore individual differences between survey and UI employment and earnings reports for a Wisconsin sample of current and former welfare recipients. After exploring the potential causes of misreports from both sources, we document the degree of discrepancy between survey and UI earnings and employment measures and assess the difference between the two earnings measures in estimates of simple human capital (earnings) functions. Last, we evaluate the correspondence of the two measures with “hardship” indicators of economic well-being.
Comparison of Muscle Activities Using a Pressure Biofeedback Unit during Abdominal Muscle Training Performed by Normal Adults in the Standing and Supine Positions

[Purpose] The purpose of this study was to assess the effects of draw-in exercise on abdominal muscle activity in the standing and supine positions. [Methods] Twenty healthy women participated in this study. The subjects were required to complete two draw-in exercises (standing and supine positions) using a biofeedback pressure unit. The root mean square (RMS) values of the EMG data were expressed as a percentage of the resting contraction. The data were analyzed using the independent t-test. [Results] According to the changes in the activities of the abdominal muscles, the draw-in exercise in the standing position produced the most significant increase in the activities of the rectus abdominis, the transverse abdominis, the internal oblique, and the external oblique muscles. [Conclusion] The activities of the trunk stability muscles (rectus abdominis, transverse abdominis, internal oblique, and external oblique) increased more in the standing than in the supine position, enabling the subjects to overcome gravity. Therefore, to strengthen the activation of the abdominal muscles, a standing position seems to be more effective than a supine position for draw-in exercises.
Language and identity among speakers of Spanish in northern Morocco: Between ethnolinguistic vitality and acculturation1

L'A. analyse les strategies developpees par un groupe linguistique minoritaire pour preserver leur identite linguistique et conserver leur heritage linguistique sans avoir a faire face a une pression sociale et institutionnelle particuliere. Il examine la vitalite de cette minorite linguistique d'une part et l'acculturation des membres de la majorite linguistique d'autre part
Static and dynamic fracture strength of Barre granite

Abstract The stress-strain curves to failure and the fracture of Barre granite are investigated using split Hopkinson bar techniques as well as quasi-static procedures. In addition to dynamic torsion tests, tension experiments were executed at loading rates ranging from 10−5 s−1 to 10 s−1, while the compression tests were performed in the range from 10−5 s−1 to 103s−1. Both modulus and fracture strength in tension and compression were found to be strain-rate dependent with greater sensitivity exhibited for the failure property. It was assumed a priori that the values of the strengths along the three principal axes for all modes of loading would be different since the magnitudes of the stiffness had been reported by other investigators to exhibit directional characteristics. This was found to be the case for all types of dynamic loading conditions; however, within experimental error, two of these directions yielded essentially the same value. The dynamic tensile stiffness and the static compressive strength appeared to be essentially independent of orientation. The material exhibited a hysteresis loop under static and dynamic cyclic loading below fracture, but no significant permanent deformation was noted in any of the tests.
Cytological virological and chromosomal studies of cell strains from aborted human fetuses.

SummaryAn organ culture technique was used to investigate the possibility that latent viruses are present in spontaneously aborted human fetuses. All attempts to isolate virus from 74 human embryos were negative. In the course of these studies, numerous cell strains were derived from human tissue, and cytological features of these cells are described. Multinucleated giant cells were frequently found, but chromosomal aberration in this material was infrequent.
Vaccines for Acinetobacter baumannii: thinking "out of the box".

We are indeed fortunate that modern medicine continues to offer advancements that promise better and longer lives. Delivering on that promise depends on our ability to effectively prevent and treat bacterial infections that frequently arise as complications of medical interventions. Acinetobacter baumannii has emerged as a “successful” pathogen due to its ability to readily survive in the nosocomial environment and to display myriad mechanisms of antibiotic resistance 1. Infections caused by this organism are becoming extremely difficult to prevent and treat, jeopardizing the safety of hospitalized patients. Since infection control strategies have yielded limited benefit against the spread of A. baumannii, and new antibiotics active against multidrug resistant A. baumannii will not be available in the very near future, unconventional approaches are urgently needed to counter the threat posed by this pathogen. Vaccines have long helped to reduce the burden of bacterial infection but, until now, have only seldom targeted nosocomial pathogens. In a commentary recently written by Pachon and McConnell, a cogent argument for the development of a vaccine to protect against A. baumannii is advanced. Guided by knowledge of the clinical syndromes caused by A. baumannii, the authors identify key populations that may benefit from prophylactic vaccination, such as patients supported by mechanical ventilation or who have sustained burns, and military personnel at risk for war-related trauma. The unpredictability of these events is recognized on economic grounds as an obstacle to plan an eventual immunization strategy. Furthermore, such a strategy must be balanced with the time required to achieve protective and durable immunity. In terms of developing an effective vaccine, the importance of selecting appropriate antigens is reviewed, including outer membrane and biofilm associated proteins, polysaccharides, and inactivated whole cells. In their analysis, Pachon and McConnell are careful to recognize obstacles that may stand in the way of a future vaccine against A. baumannii.
Using BIRADS categories in ROC experiments

This paper investigated the use of the Breast Imaging Reporting And Data System (BIRADS) Lexicon in ROC mammography experiments. Analysis was based on data from parallel ROC experiments performed at two Institutions with different readers and databases to compare film to digitized mammography. Seven readers participated in the studies and read approximately 200 cases each in two formats: film and digital or softcopy. Reporting was done using BIRADS categories 1 through 5. Training was done with a separate set of cases and included detailed review of the relationship between BIRADS and a standard ROC discrete 5-point rating scale. The results from both sites showed equivalency between film and softcopy mammography. Decisions using the BIRADS categories showed no unsampled ROC regions and no degenerate data. Fits yielded smooth ROC curves that correlated to clinical practice. In a qualitative evaluation, all observers indicated preference in using the BIRADS classes instead of a discrete or continuous rating scheme. Familiarity with the rating process seems to relieve some of the bias associated with the interpretation of digitized mammograms from computer monitors (softcopy reading). Our results suggested that BIRADS categories can be used in comparative ROC studies because they represent a scale familiar to the reader that can be followed consistently and they provide a rating approach that accounts for both positive and negative cases to be evaluated and categorized.
GENETIC ENGINEERING APPROACHES TO ENZYME DESIGN AND MECHANISM

Aspartate aminotransferase (AATase) and aminocyclopropane carboxylate synthase (ACC synthase) are pyridoxal phosphate (PLP)-dependent enzymes whose common junction of mechanistic divergence is after the formation of a Cα carbanion from the amino acid substrate bound to PLP as a Schiff base (aldimine). AATase catalyzes the reversible interconversion of α-amino acids and α-keto acids, while ACC synthase effects the irreversible decomposition of S-adenosylmethionine (SAM) to 1-aminocyclopropane-1-carboxylate (ACC) and 5′-methylthioadenosine (MTA). ACC is subsequently converted to ethylene, the plant ripening and senescence hormone, by ACC oxidase, the next enzyme in the pathway. AATase and ACC synthase exhibit many similar phenomenological characteristics that result from different detailed mechanistic origins. The kcat/KMversus pH profiles for both enzymes are similar (AATase, acidic pKa = 6.9, basic pKa = 9.6; ACC synthase, acidic pKa = 7.5, basic pKa = 8.9); however the acidic pKa of AATase reflects the ionization of an enzyme proton from the internal Schiff base, and the basic one is that of the α-amino group of the substrate, while the opposite situation obtains for ACC synthase, i.e. the apparent pKa of 7.4 is due to the α-amino group of SAM, whereas that of 9 reflects the Schiff base pKa. The mechanistic imperative underlying this reversal is dictated by the reaction mechanism and the low pKa of the α-amino group of SAM. The low pKa of SAM requires that the enzyme pKa be moved upward in order to have sufficient quantities of the reacting species at neutral pH. It is shown by viscosity variation experiments with wild-type and active site mutant controls of both enzymes that the reaction of SAM with ACC synthase is 100% diffusion controlled (kcat/KM = 1.2 × 106 l mol−1 s−1) while the corresponding reaction for the combination of L-aspartate with AATase is insensitive to viscosity, and is therefore chemically not diffusion limited. Tyr225 (AATase) or Tyr233 (ACC synthase) forms a hydrogen bond with the PLP in both enzymes, but that formed with the former enzyme is stronger and accounts for the lower pKa of the Schiff base. © 1998 John Wiley & Sons, Ltd.
What “question-asking protocols” can say about the user interface

To make computer systems easier to use, we are in need of behavioral data which enable us to pinpoint what specific needs and problems users may have. Recently, the “thinking-aloud protocol” method was adopted as a technique for studying user behaviours in interactive computer systems. In the present paper, the “question-asking protocol” method is proposed as a viable alternative to the thinking-aloud method where the application of the latter is difficult or even inappropriate. It is argued that question-asking protocols shed light on (1) what problems users experience in what context, (2) what instructional information they come to need, (3) what features of the system are harder to lean, and (4) how users may come to understand or misunderstand the system.