cssi/SciSciGPT-SciSciNet huggingface dataset:
Actinorhizal species influence plant and soil nitrogen status of semiarid shrub-dominated ecosystems in the western Great Basin, USA

Abstract Actinorhizal plants form symbiotic root associations with dinitrogen (N2) fixing Frankia and are abundant in North American cold deserts. However, the extent to which actinorhizal species are actively fixing N2 or altering ecosystem nitrogen (N) availability remains unclear. We used the 15N natural abundance technique to measure how three widespread actinorhizal species in the western Great Basin of western North America acquired N and influenced soil N cycling and the N status of the surrounding non-fixing plant community. We compared foliar and soil N concentrations and δ15N and soil biogeochemistry between reference plots and plots dominated by actinorhizal species. Actinorhizal species may be actively fixing N and influencing the N status of the surrounding ecosystem. Foliar δ15N of actinorhizal shrubs was significantly depleted compared to non-actinorhizal species. Non-actinorhizal plants in the presence of actinorhizal species showed depleted foliar δ15N and higher foliar N concentrations than in reference plots. Rates of N transformations in reference plots were similar to rates in actinorhizal plots; isotopic differences between plot types could not be explained by differences in N loss pathways. Actinorhizal species influence N cycling and availability in N-limited cold deserts, in a manner similar to leguminous plants in warm arid regions.
Demographic Processes and Population Dynamic Models of Seabirds

Seabirds, like many taxa of birds in the 19905, face numerous conservation challenges. The primary challenge is to maintain or restore populations in the face of destruction of habitat, introduction of non-native predators, human disturbance (including hunting and collecting),.oil spills, and the like. The low reproductive rates and deferred maturity of seabirds exacerbate the problems (Buckley and Downer, 1992; Croxall and Rothery, 1991), which makes recovery from catastrophic events difficult or even impossible. Seen in this light, nearly all seabird populations can be categorized as “vulnerable,” if not “threatened” or “endangered”; hardly any can be categorized as “not vulnerable” (cf. Mace and Lande, 1991). Over the past decade a multitude of disturbances has affected seabirds, including several major oil spills, of which the Exxon Valdez oil spill is surely the most prominent (Rice et al., 1996; Piatt et al.,1990). Events such as these oil spills have focused the attention of the public, government agencies, and the scientific community on the doubled-headed question: What are the long-term effects of such disturbance, and can seabirds recover from the assault? Interest in answering questions like these is heightened by concern about major oceanographic perturbations, including El Nino events, and activities of commercial fisheries, which could very well undermine the prey base for many seabirds.
The effect of family history on adherence to breast cancer screening guidelines.

1571 Background: A family history of breast cancer increases the risk of developing this disease. We sought to determine the effect of a family history of a first degree relative with breast cancer (FDFHx) on adherence to mammography (MMG) and clinical breast examination (CBE) guidelines. Methods: The National Health Interview Survey (NHIS), conducted annually by the Centers for Disease Control, is designed to be representative of the US population. The 2010 NHIS data was used to evaluate the effect of FDFHx on the likelihood that women aged ≥ 30 had MMG and/or CBE within the past year. Results: Of the 12,320 women aged ≥ 30, 1276 (10.7%) had a FDFHx; 1263 (99.0%) of female breast cancer and 13 (1.0%) of male breast cancer. Overall, 4573 (38.4%) of women reported having had MMG within the past year; 5377 (46.3%) had CBE within the past year. FDFHx was associated with use of MMG and CBE within the past year (58.0% vs. 36.0%, p<0.001, and 57.5% vs. 45.0%, p<0.001, respectively). Women with a FDFHx of male b...
Extremophile Biology for Microbial Electrochemistry Applications

Abstract “Extremes” include the physical (pressure, radiation, and temperature) and geochemical limits (desiccation, oxygen levels, pH, salinity, and redox potential) that challenge the physical and metabolic functions of typical life. Extremophiles survive and thrive in the harsh conditions. Recent studies demonstrate the existence of industrially relevant extremophiles in remote geographical locations, including harsh environments in hot springs and deeper biospheres. They can be isolated and used in a range of environmental biotechnology applications including microbial electrochemical systems (MESs). This chapter focuses on the following aspects in the MESs: (1) an overview of the extremophiles, (2) the survival strategies and electron transfer mechanism, (3) the potential applications of extremophiles, and (4) the potential engineering challenges (material degradation challenges).
Relationship between Parathyroid Hormone Levels and Hazards of Fracture, Vascular Events and Death in Stage 3 and 4 Chronic Kidney Disease

Abstract Background and Objectives: Chronic kidney disease (CKD) affects ∼20% of older adults and secondary hyperparathyroidism (HPT) is a common condition in these patients. Studies have linked HPT to a greater risk of fractures, vascular events and mortality. However, the optimal parathyroid hormone (PTH) level needed to minimize these events remains uncertain. Design, setting, participants and measurements: We assessed relationships between baseline serum PTH levels and the subsequent 10-year probability of clinical fractures, vascular events and death in stage 3 and 4 CKD patients. We used Marshfield Clinic Health System electronic health records to analyze data from adult CKD patients spanning from 1985 to 2013. We required ≥2 PTH measurements at baseline and used ICD-9 codes to identify medical conditions, fractures, vascular events and death. In multivariate models, we assessed relationships between serum PTH and the three clinical outcomes, controlling for age, gender, co-morbidities and osteoporosis medication. Results: 7594 subjects had a mean age of 68±13 years and 55% were women. Fractures, vascular events and death occurred in 19%, 60% and 29% of the cohort, respectively. In multivariate models including the whole cohort regardless of PTH assay, the probability of fracture, vascular events and death were minimized at a PTH of 23, 50 and 50 pg/mL. Below these cutpoints, the probability of fractures and death dramatically increased. When confining the analysis to patients measured using a 2nd generation PTH assay (n=5108), the hazards of fracture, vascular events and death were minimized at a PTH of zero, 60 and 58 pg/mL. Any of these clinical outcomes was minimized at a baseline PTH of 58 pg/mL. Conclusions: Our study suggests that parathyroid hormone levels around 60 pg/mL might reduce the risk of fractures, vascular events and death in CKD patients. Additional epidemiologic studies and randomized clinical trials are needed to confirm these findings.
A Block Diagram Approach to Stochastic Calculus with Application to Multiplicative Uncertainty Analysis

We consider the continuous-time setting of linear time-invariant (LTI) systems in feedback with multiplicative stochastic uncertainties. The objective of the paper is to characterize the conditions of Mean-Square Stability (MSS) using a purely input-output approach, i.e. without having to resort to state space realizations. This has the advantage of encompassing a wider range of models (such as infinite dimensional systems and systems with delays). This approach leads to uncovering new tools such as stochastic block diagrams that have an intimate connection with the more general stochastic integral equations (SIE), rather than stochastic differential equations (SDE). Various stochastic interpretations are considered, such as Itō and Stratonovich, and block diagram conversion schemes between different interpretations are devised. The MSS conditions are given in terms of the spectral radius of a matrix operator that takes different forms when different stochastic interpretations are considered.
Management of High Energy Distal Radius Injuries

High energy distal radius are commonly multi-fragmentary with significant comminution and/or bone loss. They can also be associated with ligamentous and soft tissue injury and neurovascular compromise. As such, reconstruction of these injuries can be challenging. This paper will review the relevant anatomy, different methods of fixation, and present techniques for difficult fractures. Volar locked plating is a successful, very common method of treatment for distal radius fractures, but dorsal plating, fragment specific fixation, spanning bridge plating, and external fixation are sometimes necessary, particularly in higher energy injuries characterized by metaphyseal comminution, small volar fragments, intra-articular free fragments or lunate facet subsidence. Extended flexor carpi radialis (FCR), dorsal, and flexor carpi ulnaris (FCU) exposures can assist in visualizing the fracture site. There are many different modes of fixation for distal radius fractures, and successful outcome depends on selection of appropriate fixation based on the fracture pattern and status of the soft tissues.
Assortative mating and the dynamical decoupling of genetic admixture levels from phenotypes that differ between source populations

Source populations for an admixed population can possess distinct patterns of genotype and phenotype at the beginning of the admixture process. Such differences are sometimes taken to serve as markers of ancestry---that is, phenotypes that are initially associated with the ancestral background in one source population are taken to reflect ancestry in that population. Examples exist, however, in which genotypes or phenotypes initially associated with ancestry in one source population have decoupled from overall admixture levels, so that they no longer serve as proxies for genetic ancestry. We develop a mechanistic model for describing the joint dynamics of admixture levels and phenotype distributions in an admixed population. The approach includes a quantitative-genetic model that relates a phenotype to underlying loci that affect its trait value. We consider three forms of mating. First, individuals might assort in a manner that is independent of the overall genetic admixture level. Second, individuals might assort by a quantitative phenotype that is initially correlated with the genetic admixture level. Third, individuals might assort by the genetic admixture level itself. Under the model, we explore the relationship between genetic admixture level and phenotype over time, studying the effect on this relationship of the genetic architecture of the phenotype. We find that the decoupling of genetic ancestry and phenotype can occur surprisingly quickly, especially if the phenotype is driven by a small number of loci. We also find that positive assortative mating attenuates the process of dissociation in relation to a scenario in which mating is random with respect to genetic admixture and with respect to phenotype. The mechanistic framework suggests that in an admixed population, a trait that initially differed between source populations might be a reliable proxy for ancestry for only a short time, especially if the trait is determined by relatively few loci. The results are potentially relevant in admixed human populations, in which phenotypes that have a perceived correlation with ancestry might have social significance as ancestry markers, despite declining correlations with ancestry over time.
Identification of Leukemia Stem Cells Associated with AML1-ETO through Characterization of Oncogene-Induced Changes in Cell Surface Antigen Profiles on Hematopoietic Stem Cells.

Acute myelogenous leukemia (AML) is a heterogenous group of myeloid malignancies that are characterized by the clonal outgrowth of immature myeloid progenitor cells. For most subtypes of AML, mutations that give rise to the leukemic phenotype occur in the hematopoietic stem/progenitor cell (HSC) subset as demonstrated by studies showing that only primitive CD34+CD38− bone marrow cells could function as leukemia-initiating cells (LSC) when transferred into immunodeficient NOD-SCID mice. One rather significant challenge has been that LSC share many of the same cell-surface markers as their normal counterparts in bone marrow, thus making it difficult to functionally characterize and purify this important subset of leukemic cells from bulk bone marrow samples. To rapidly identify novel antigens that are mutation-specific and induced specifically on LSC and not on normal HSC, we have transduced highly purified HSC isolated from mouse bone marrow with retroviral vectors that co-expressed AML1-ETO along with a green fluorescent protein (GFP) reporter gene. HSC of the cell-surface phenotype c-Kit+Lin−Sca-1+Flt3− (KLSF) were transduced for 18 hours in vitro and then were resorted for GFP+ cells by flow cytometry (FACS). Purified cells were then lysed for mRNA isolation and cDNA synthesis for the generation of a probe that was then hybridized to Affymetrix oligonucleotide arrays (430 2.0 GeneChip arrays). HSC transduced with a retroviral vector that only expressed GFP were used as controls to identify genes that would normally be expressed in the HSC subset. Importantly, since retroviral vectors only integrate into cycling cells, all sorted GFP+ cells from the independent transductions would represent cycling cells, which minimizes any gene expression differences due to differential frequencies of resting versus actively cycling HSC. Changes in expression of cell-surface proteins observed at the mRNA level were then validated at the protein level using FACS. Bone marrow cells were isolated from an animal that was transplanted with cells expressing AML1-ETO and GFP from a retroviral vector. Cells were stained for the HSC/progenitor cell phenotype (KLS) as well as for the cell-surface marker of interest. For one marker, CD55, we noted a 100-fold increase in cell-surface expression specifically on HSC that express AML1-ETO and not on normal HSC. These results indicate that short-term retroviral expression of specific AML-associated mutations in HSC followed by microarray analysis of transduced cells may provide a rapid means of prospectively identifying leukemia-initiating cells in bulk patient bone marrow samples and that CD55 may be a useful therapeutic and diagnostic marker for patient samples that express the AML1-ETO chromosomal translocation.
Dismantling Rape Culture: The Peacebuilding Power of ‘Me Too’

This book analyses rape culture through the lens of the ‘me too’ era. Drawing feminist theory into conversation with peace studies and improvisation theory, it advocates for peace- building opportunities to transform culture and for the improvisatory resources of ‘culture- jamming’ as a mechanism to dismantle rape culture. The book’s key argument is that cultural attitudes and behaviours can be shifted through the introduction of disrupting narratives, so each chapter ends with a ‘culture- jammed’ re- telling of a traditional fairy tale. Chapter 1 traces an overlap of feminist theory and peace studies, arguing that rape culture is most fruitfully understood through the concept of ‘structural violence.’ Chapter 2 investigates the gender scripts that rape culture produces, considering a female counterpart to the concept of ‘toxic masculinity’: ‘complicit femininity.’ Chapter 3 offers analysis of non- consensual sex and a history of consent education, culminating in an argument that we need to move beyond consent to conceptualise a robust ‘respectful mutuality.’ Chapter 4 ’s history of sexual harassment in the workplace and the rise of #metoo argues that its global manifestations are a powerful peace- building initiative. Chapter 5 situates ‘me too’ within a culture- jamming history, using improvisation theory to show how this movement’s potential can shape cultural reconstruction. This is a provocative and interventionist addition to feminist theory scholarship and is suitable for researchers and students in women’s and gender studies, feminist theory, sociology and peace studies.
Use of donor-derived-cell-free DNA as a marker of early allograft injury in primary graft dysfunction (PGD) to predict the risk of chronic lung allograft dysfunction (CLAD).

Abstract Background Primary Graft Dysfunction (PGD) is a risk factor for Chronic Lung Allograft Dysfunction (CLAD). However, the association between PGD and degree of allograft injury remains poorly defined. In this study, we leverage a novel biomarker for allograft injury, percentage donor-derived cell-free DNA (%ddcfDNA), to study the association between PGD, degree of allograft injury, and the development of CLAD. Methods This prospective cohort study recruited 99 lung transplant recipients and collected plasma samples on days 1, 3 and 7 for %ddcfDNA measurements. Clinical data on day 3 was used to adjudicate for PGD. %ddcfDNA levels were compared between PGD grades. In PGD patients, %ddcfDNA was compared between those who developed CLAD and those who did not. Results On post-transplant day 3, %ddcfDNA was higher in PGD than in non PGD patients (median (IQR): 12.2% (8.2, 22.0) vs 8.5% (5.6, 13.2) p = 0.01). %ddcfDNA correlated with the severity grade of PGD (r = 0.24, p = 0.02). Within the PGD group, higher levels of %ddcfDNA correlated with increased risk of developing CLAD (log OR(SE) 1.38 (0.53), p=0.009). PGD patients who developed CLAD showed ∼2 times higher %ddcfDNA levels than patients who did not develop CLAD (median (IQR): 22.4% (11.8, 27.6) vs. 9.9% (6.7, 14.9), p = 0.007). Conclusion PGD patients demonstrated increased early post-transplant allograft injury, as measured by %ddcfDNA, in comparison to non PGD patients, and these high %ddcfDNA levels were associated with subsequent development of CLAD. This study suggests that %ddcfDNA identifies PGD patients at greater risk of CLAD than PGD alone.
The Efficacy of Liposomal Bupivacaine for Opioid and Pain Reduction: A Systematic Review of Randomized Clinical Trials.

Abstract Background The opioid crisis has prompted surgeons to search for alternative postoperative methods of analgesia. Liposomal bupivacaine is a long-acting local anesthetic formulation used for pain, potentially reducing opioid use. Evaluation of liposomal bupivacaine as a viable alternative for pain management is needed. The objective was to assess the efficacy of randomized clinical trials (RCTs) of liposomal bupivacaine in postoperative pain management and opioid consumption. Material and Methods The authors extracted RCTs comparing liposomal bupivacaine versus placebo or active comparators for postoperative pain or opioid reduction from PubMED/MEDLINE, Cochrane Library, and ClinicalTrials.gov. Exclusion criteria included nonhuman studies, non-RCTs, pooled studies, and inability to access full text. The following variables were abstracted: surgical specialty, number of subjects, pain and opioid outcomes, and authors’ financial conflicts of interest. Results We identified 77 published RCTs, of which 63 studies with a total of 6770 subjects met inclusion criteria. Liposomal bupivacaine did not demonstrate significant pain relief compared to placebo or active agents in 74.58% of RCTs. Of the studies evaluating narcotic use, liposomal bupivacaine did not show a reduction in opioid consumption in 85.71% of RCTs. Liposomal bupivacaine, when compared to standard bupivacaine or another active agent, yielded no reduction in opioid use in 83.33% and 100.00% of studies, respectively. Clinical trials with a financial conflict of interest relating to the manufacturer of liposomal bupivacaine were significantly more likely to show pain relief (OR: 14.31 [95% CI, 2.8, 73.10], P = 0.0001) and decreased opioid consumption (OR: 12.35 [95% CI 1.40, 109.07], P = 0.0237). Of the 265 unpublished RCTs on ClinicalTrials.gov, 47.54% were withdrawn, terminated, suspended, or completed without study results available. Conclusions The efficacy of liposomal bupivacaine for providing superior postoperative pain control relative to placebo or another active agent is not supported by a majority of RCTs. Underreporting of trial results and bias due to underlying financial relationships amongst authors are two major concerns that should be considered when evaluating the available evidence.
Outcomes of Neoadjuvant Chemotherapy for Clinical Stages 2 and 3 Gastric Cancer Patients: Analysis of Timing and Site of Recurrence.

This study aimed to analyze timing and sites of recurrence for patients receiving neoadjuvant chemotherapy for gastric cancer. Neoadjuvant chemotherapy followed by surgical resection is the standard treatment for locally advanced gastric cancer in the West, but limited information exists as to timing and patterns of recurrence in this setting. Patients with clinical stage 2 or 3 gastric cancer treated with neoadjuvant chemotherapy followed by curative-intent resection between January 2000 and December 2015 were analyzed for 5-year recurrence-free survival (RFS) as well as timing and site of recurrence. Among 312 identified patients, 121 (38.8%) experienced recurrence during a median follow-up period of 46 months. The overall 5-year RFS rate was 58.9%, with RFS rates of 95.8% for ypT0N0, 81% for ypStage 1, 77.4% for ypStage 2, and 22.9% for ypStage 3. The first site of recurrence was peritoneal for 49.6%, distant (not peritoneal) for 45.5%, and locoregional for 11.6% of the patients. The majority of the recurrences (84.3%) occurred within 2 years. Multivariate analysis showed that ypT4 status was an independent predictor for recurrence within 1 year after surgery (odds ratio, 2.58; 95% confidence interval, 1.10–6.08; p = 0.030). The majority of the recurrences for patients with clinical stage 2 or 3 gastric cancer who received neoadjuvant chemotherapy and underwent curative resection occurred within 2 years. After neoadjuvant chemotherapy, pathologic T stage was a useful risk predictor for early recurrence.
Response times in the wild: eBay sellers take hours longer to reject high offers and accept low offers

Hesitation in the marketplace has the potential to betray private information. Recent results from lab experiments have confirmed that subjects’ response times reveal their strength-of-preference or belief, even in strategic settings. What remains unclear is whether these results extend beyond the lab to markets with experienced agents. Here we address this question using a dataset consisting of millions of bargaining exchanges from eBay. We find that the time it takes sellers to accept or reject offers is strongly related to the size of the offer. Sellers are quick to accept good offers and to reject bad offers, and slow to accept bad offers and to reject good offers. These response-time differences are on the order of hours. These findings apply to a majority of the exchanges on eBay, and are even stronger with more experienced sellers. Overall, these results indicate that there is information in response-time data from non-lab markets, and that a majority of agents do not have prepared strategies but instead evaluate offers on the spot in a way that reveals their values for the goods.
Into the Woods: The Creaturely and the Queer in 20th Century US American Hunting Narratives

This chapter analyzes intertextual representations of white American masculinity and its human and nonhuman others as they arise across a referential chain of three 20th Century hunting novels: William Faulkner’s Go Down Moses (1942), Norman Mailer’s Why Are We in Vietnam? (1967), and James Dickey’s Deliverance (1970). The chapter locates these texts within two historical, political, and conservationist contexts: first, the emergence of federal wilderness enclosure programs and white men’s outdoors and eugenics organizations in the 1910s–40s, and second, within the backdrop of the Vietnam War and the social and environmental movements of the 1960s. Throughout my analysis of textual representations of hunting, racialized and colonial inhumanity, and nonhuman animality in these texts. I develop a queer ecological and critical race theory of “the creaturely.” This theory responds to work from Alex Weheliye, Sarah Ensor, and Donna Haraway, and articulates the posture of environmental attunement, interspecies identification, and interracial alliance that emerges in these texts among queer, racialized, and colonized humans and the nonhuman animals and ecologies that make life under the shadow of ritualized violence.
News Values vs. Gospel Values. Religious messages in the media – case study of celebrity gossip column “Virtues and Vices”

News Values vs. Gospel Values. Religious messages in the media – case study of celebrity gossip column “Virtues and Vices”. By conveying religious messages through a media communication channel, researches often point to the “news non-value” of religious events. This is a conflict between “news values” (headed by conflict) and “gospel values” (which are Christian virtues). However, some religious topics are also interesting for the secular media. Among them, the most popular are the stories and fortunes of well-known people (and their private lives). The Slovak weekly, “.týždeň”, has published a regular column of Virtues and Vices, since 2011, in which celebrities – including many Christians – openly talk about their strengths and weaknesses. This study offers a content analysis of the presented virtues and vices; answering the question, what (Christian) virtues and their negations are of interest to the secular media?
A Class Of Social Choice Mechanisms Possessing Pure-Strategy Nash Equilbria

A class of social choice mechanisms is described. Each mechanism in the class, when viewed as a noncooperative game, is shown to possess at least one Nash equilibrium in pure strategies. Some members of the class are useful in social choice applications.
Synthesis of Self-Timed Circuits

This chapter describes a synthesis procedure of designing digital systems that do not require the distribution of a clocking signal. Guarded commands [1] were chosen to provide a simple syntax for circuit specifications. The notation of signal transition graphs [2] was used to represent circuit behavior and to simplify algorithms and graph manipulations. The definition of semi-modularity [3] was modified and the theorems developed for marked directed graphs [4] were used to guarantee a hazard-free implementation. All together, a deterministic algorithm of synthesizing self-timed synchronization circuits from high-level specifications was constructed. The implication is that fully asynchronous design (or more precisely, asynchronous design using anisochronous interconnect according to the previous chapter) is feasible and self-timed circuit synthesis can be automated. Although in this chapter we are primarily concerned with the synthesis of non-metastable circuits, the procedure is also valid for metastable circuit synthesis.
In Vivo Kinetics of Nitrogenase Formation in Clostridium pasteurianum

Clostridium pasteurianum exhibits diauxic growth when grown in the presence of both NH 3 and N 2 ; no nitrogenase activity or formation was detected either serologically or by activity during growth on NH 3 . During the 60-min lag that ensued after NH 3 was consumed and before growth resumed, molybdoferredoxin and azoferredoxin were first detected by activity measurements and serologically at 25 and 40 min, respectively. With the use of rifampin and dactinomycin, it was found that azoferredoxin messenger ribonucleic acid was initiated between 25 and 30 min after the inception of the lag and was completed by 38 min. An explanation of these results and their relation to possible models for the regulation of nitrogenase is given. Images
Who Are Our Students? A Statistical Portrait of Immigrant Students in New York City Elementary and Middle Schools.

Major increases in immigration and the shift in immigrant origins over the past three decades have substantially changed the composition of New York City's public schools. Unlike their primarily European predecessors, today's immigrant students come from countries all over the world, speak a wide variety of languages, and present a range of educational needs and prior schooling experiences. Where do immigrant students come from? How many are new arrivals to the school system? How do their experiences and backgrounds differ from the native-born? This report answers these and other important questions through a statistical portrait of the demographic characteristics and educational experiences of immigrant students in New York City's elementary and middle schools.
Computational Models of Cognition: Constraining

Computational models of cognition may be constrained in various ways. The three primary benefits of constraining a computational model are: (1) parsimony; (2) avoiding over-flexibility; and (3) potentially stronger motivation for the elements of the model. Keywords: computational models; constraints; overfitting; motivation
Policing in public housing: Using calls for service to examine incident‐based workload in the Philadelphia Housing Authority

The present analysis examines police incident‐based activity in a public housing setting. Calls for service to the Philadelphia Housing Authority Police Department are described by call types in order to identify requests for police services by residents of the Philadelphia Housing Authority. Findings from the current research are compared and contrasted to what has been discovered about incident‐based activity in municipal police departments. The analysis reveals that public housing police respond in about the same proportion as municipal police to calls for service related to public order and (in some cases) reactive law enforcement, but that differential service demands exist, which are identified and placed in the public housing context. Additionally, it is found that incident‐driven activity levels in public housing are much lower than criminological research on crime in public housing might suggest. Implications for future research are discussed.
The Requirements Entropy Framework in Systems Engineering

This paper introduces a requirements entropy framework REF for measuring requirements trends and estimating engineering effort during system development. The REF treats the requirements engineering process as an open system in which the total number of requirements R transition from initial states of high requirements entropy HR, disorder and uncertainty toward the desired end state of HR min as R increase in quality. The cumulative requirements quality Q reflects the meaning of the requirements information in the context of the SE problem. The distribution of R among N discrete quality levels is determined by the number of quality attributes accumulated by R at any given time in the process. The number of possibilities P reflects the uncertainty of the requirements information relative to HR min . The HR is measured or estimated using R, N and P by extending principles of information theory and statistical mechanics to the requirements engineering process. The requirements information I increases as HR and uncertainty decrease, and ΔI is the additional information necessary to achieve the desired state from the perspective of the receiver. The HR may increase, decrease or remain steady depending on the degree to which additions, deletions and revisions impact the distribution of R among the quality levels. Current requirements volatility metrics generally treat additions, deletions and revisions the same and simply measure the quantity of these changes over time. The REF measures the quantity of requirements changes over time, distinguishes between their positive and negative effects in terms of Q,HR, and ΔI, and forecasts when a specified desired state of requirements quality will be reached, enabling more accurate assessment of the status and progress of the engineering effort. Results from random variable simulations suggest the REF is an improved leading indicator of requirements trends that can be readily combined with current methods. The additional engineering effort ΔE needed to transition R from their current state to the desired state can also be estimated. Simulation results are compared with measured engineering effort data for Department of Defense programs, and the results suggest the REF is a promising new method for estimating engineering effort for a wide range of system development programs.
Fecal protoporphyrin excretion in erythropoietic protoporphyria: Effect of cholestyramine and bile acid feeding

The effect of cholestyramine and bile acid feeding upon fecal, red blood cell, and plasma protoporphyrin levels was evaluated in a patient with erythropoietic protoporphyria and evidence of hepatic damage. After a basal period on a controlled diet, bile acids alone were administered (300-900 mg) daily for 9 days, followed by cholestyramine (12 g) plus bile acids (900 mg) daily for 7 days, and cholestyramine alone (12 g) daily for 6 days. There was no substantial change in either the red blood cell or plasma protoporphyrin concentrations during any treatment period. However, cholestyramine and cholestyramine combined with bile acids caused a threefold increase in fecal protoporphyrin excretion, whereas bile acids alone had no effect in this regard. After 1 yr of cholestyramine therapy, fecal excretion of protoporphyrin remained elevated with concurrent improvement in liver function tests and photosensitivity. This study indicates that cholestyramine but not bile acids can substantially increase protoporphyrin excretion and therefore may be capable of ameliorating the hepatotoxicity that may occur in selected patients with erythropoietic protoporphyria.
Sperm competition between Drosophila males involves both displacement and incapacitation

Females in almost all animal groups copulate with multiple males1,2. This behaviour allows different males to compete for fertilization3 and gives females the opportunity to mediate this competition4. In many animals and most insects, the second male to copulate with a female typically sires most of her offspring1,5,6. In Drosophila melanogaster, this second-male sperm precedence has long been studied7,8,9,10,11,12,13,14,15 but, as in most species, its mechanism has remained unknown. Here we show, using labelled sperm in doubly mated females, that males can both physically displace andincapacitate stored sperm from earlier-mating males. Displacement occurs only if the second male transfers sperm to the female, and in only one of her three sperm-storage organs. Incapacitation can be caused by either fertile or spermless second males, but requires extended intervals between matings. Sperm from different males are not ‘stratified’ in the storage organs but mix freely. Many animal species may have multiple mechanisms of sperm competition like those observed here, and revealing these mechanisms is necessary to understand the genetic and evolutionary basis of second-male sperm precedence in animals.
Liposomes in the study of membrane fusion in neutrophils.

Publisher Summary This chapter introduces lipid-mixing and content-mixing assays, which are useful for studying fusion in neutrophils. The advantages and disadvantages of both systems are also described. Lipid-mixing assays are easy to employ and can be used on any membrane. Lipid exchange could occur across apposed membrane surfaces. Attempts to label biological membranes with highly hydrophobic compounds could leave adherent micelles of the probe that, under suitable conditions, the membrane might dissolve or partition into available membranes, giving a false-positive signal. Membrane disruption due to lytic agents, added exogenously or generated endogenously also gives a false-positive signal. Thus, the action of a detergent might be interpreted as fusion, if viewed uncritically. The key to conducting unambiguous fusion studies is to use a content-mixing assay. In these assays, membrane vesicles (either natural or artificial) containing two different materials are allowed to fuse, such that the contents react within a single resulting vesicle. Devising a content-mixing assay is greatly simplified when endogenous vesicle contents can be manipulated.
A layered architecture for intelligent controllers

The subject architecture under development is intended to provide a universal framework suitable for the evolution of a coordinated and detailed definition of a distributed system of intelligent controllers, their plants and inherent interactions. It is based upon a fundamental way in which intelligent controllers may go about coping with uncertainty. It provides a broad but non-exhaustive general description of a reference model (RM) for a common understanding of systems embedded with intelligent controllers and an insight into their design and behavior. The RM includes generic and analog extensions to the International Standards Organization (ISO), Open System Interconnection (OSI) RM [1] as described in the C/sup 3/RM [2,3] and as extended herein. The RM embraces anologous architectures for all the key types of physical interactions and utilizes the application layer to provide command and control over all types of interactions in an integrated fashion. The goal of this RM is also to provide a framework to guide the development of a coherent set of standards, specifications and implementations of interoperability among intelligent controllers within the framework of command and control and to protect extensive investments in modular reuseable technologies. The RM may also be used to assess the level of intelligence for intelligent controllers. Namely, as more services and functions are integrated to solve for a course of action under a wider range circumstances, the higher the level of intelligence.
Solvation of HF by molecular hydrogen: Helium nanodroplet vibrational spectroscopy

The low temperatures and high resolution associated with helium droplet spectroscopy are used to obtain vibrational spectra for clusters containing a single HF molecule, surrounded by multiple H2, D2, and HD molecules. For clusters with fewer than nine HD molecules, the asymmetric solvent environment experienced by the HF prevents it from internally rotating. The results suggest that, for n = 9 and larger, the solvent cage becomes highly isotropic, allowing the HF molecule to undergo nearly free rotation. For H2 and D2 the mixture of ortho and para species in the clusters makes the solvent cage anisotropic even when the first solvent shell is complete and free rotation of the HF molecule is not observed.
Global Existence for Nonlinear Diffusion Equations

Solutions of nonlinear (possibly degenerate) reaction-diffusion models are known to exist for all time if the asymptotic growth of the reaction term is not greater than that of the diffusion term. Via concavity methods, it is also known that negating such a condition results in solutions which blow up in finite time. On the other hand, two recent studies regarding the case of linear diffusion have reported on the ability for convective terms in a model to create global existence of solutions where no such result is true in their absence. In this paper, we develop a theory of global existence for a general class of reaction-diffusion-convection models which only requires a similar balance of diffusion and reaction. Our result extends previous work to models including convection, but it does not reveal the exact role of convection in yielding global solutions. Further analysis of a slightly simplified model establishes the global existence of all solutions if the reaction term grows asymptotically at a rate less than that of either diffusion or convection.
Delayed gastroduodenal emptying is an important mechanism for control of intestinal transit in short-gut syndrome.

PURPOSE : To understand the relative importance of changes in ileal smooth muscle contractility versus alteration of intestinal flow rate as control mechanisms for regulating intestinal transit in a surgical model of short-gut syndrome. METHODS : A model of short-gut syndrome was created by performing a 70% proximal small-bowel resection in dogs. Ten control and 6 animals with short-gut syndrome were instrumented with strain gauge transducers, steel collection cannulas, and a Silastic intraluminal infusion catheter in the midileum. Motor activity was analyzed by computer programs that determine frequency, amplitude, and propagation behavior of postprandial contractions. Perfusions of 14 C-poly-ethylene glycol and bolus injection of 3 H-polyethylene glycol were used to determine intestinal flow and transit rates. Total gastroduodenal emptying was determined using a 14 C-polyethylene glycol-labelled meal. RESULTS : Postprandial contraction frequency was decreased in animals with short-gut syndrome, but other significant changes in amplitude, mean area, and propagation behavior of postprandial ileal contractions were not seen. Gastroduodenal emptying and mean intestinal flow rates were markedly slower in animals with short-gut syndrome, as were intestinal transit rates. CONCLUSIONS : In this model of short-gut syndrome, the major adaptive change is decreased intestinal flow rate, related to delayed gastroduodenal emptying. The spatial organization of ileal contractions does not change substantially aside from a change in frequency which can be accounted for by transection of the intestinal wall.
Pig genomics for biomedicine.

The newly released swine genome assembly will aid research on disease models and xenotransplantation.
The architecture of the Eden system

The University of Washington's Eden project is a five-year research effort to design, build and use an “integrated distributed” computing environment. The underlying philosophy of Eden involves a fresh approach to the tension between these two adjectives. In briefest form, Eden attempts to support both good personal computing and good multi-user integration by combining a node machine / local network hardware base with a software environment that encourages a high degree of sharing and cooperation among its users.The hardware architecture of Eden involves an Ethernet local area network interconnecting a number of node machines with bit-map displays, based upon the Intel iAPX 432 processor. The software architecture is object-based, allowing each user access to the information and resources of the entire system through a simple interface.This paper states the philosophy and goals of Eden, describes the programming methodology that we have chosen to support, and discusses the hardware and kernel architecture of the system.
Translating Race across Time and Space: The Creation of Somali Bantu Ethnicity

This article reviews the creation of Somali Bantu ethnicity as an object of humanitarian intervention during Somalia's civil war. A variety of local, regional and international actors combined to create the ethnonym Somali Bantu for a group of refugees identified as a persecuted minority by the UNHCR and the US government and selected for resettlement in the United States. I track the emergence of the name and its affective dimensions for those who embrace Somali Bantu identity and assess criticisms of its authenticity and legitimacy. The creation of Somali Bantu identity reveals critical dimensions of how race is translated across time and space. Since a fundamental dimension of Somali Bantu identity is based on presumptions of racial difference, the article traces the salience of constructed difference for social hierarchies within Somalia, colonial projects in Somalia, refugee camp life in Kenya, US resettlement policy and diaspora politics in the United States.
Parallel processing for view-dependent polygonal virtual environments

This paper presents a parallel algorithm for preprocessing as well as real-time navigation of view-dependent virtual environments on shared memory multiprocessors. The algorithm proceeds by hierarchical spatial subdivision of the input dataset by an octree. The parallel algorithm is robust and does not generate any artifacts such as degenerate triangles and mesh foldovers. The algorithm performance scales linearly with increase in the number of processors as well as increase in the input dataset complexity. The resulting visualization performance is fast enough to enable interleaved acquisition and modification with interactive visualization.
Infiltration in Unsaturated Layered Fluvial Deposits at Rio Bravo: Macroscopic Anisotropy and Heterogeneous Transport

An infiltration and dye transport experiment was conducted to visualize flow and transport processes in a heterogeneous, layered, sandy-gravelly fluvial deposit adjacent to Rio Bravo Boulevard in Albuquerque, NM. Water containing red dye followed by blue-green dye was ponded in a small horizontal zone (about 0.5 by 0.5 m) above a vertical outcrop (about 4 by 2.5 m). The red dye lagged behind the wetting front due to slight adsorption, thus allowing both the wetting front and dye fronts to be observed in time at the outcrop face. After infiltration, vertical slices were excavated to the midpoint of the infiltrometer, exposing the wetting front and dye distribution in a quasi three-dimensional manner. At small scale, wetting front advancement was influenced by the multitude of local capillary barriers within the deposit. However, at the scale of the experiment, the wetting front appeared smooth with significant lateral spreading, twice that in the vertical, indicating a strong anisotropy due to the pronounced horizontal layering. The dye fronts exhibited appreciably more irregularity than the wetting front, as well as the influence of preferential flow features (a fracture) that moved the dye directly to the front, bypassing the fresh water between. To illustrate the ability of equivalent homogeneous media models to capture the behavior of the wetting front, we performed numerical simulations using equivalent homogeneous media with isotropic, anisotropic, and moisture-dependent anisotropic properties. Those containing anisotropy matched the experimental data best.
International Reference Ionosphere 2007: Improvements and new parameters

Abstract The International Reference Ionosphere (IRI), a joint project of URSI and COSPAR, is the de facto international standard for the climatological specification of ionospheric parameters and as such it is currently undergoing registration as Technical Specification (TS) of the International Standardization Organization (ISO). IRI by charter and design is an empirical model based on a wide range of ground and space data. It describes monthly averages of ionospheric densities and temperatures in the altitude range 50–1500 km in the non-auroral ionosphere. Since its inception in 1969 the IRI model has been steadily improved with newer data and with better mathematical descriptions of global and temporal variation patterns. A large number of independent studies have validated the IRI model in comparisons with direct and indirect ionospheric measurements not used in the model development. A comparison with IRI is often one of the first science tasks by an ionospheric satellite or rocket team. This paper describes the latest version of the IRI model, IRI-2007, explaining the most important changes that are being introduced with this version. These include: (1) two new options for the topside electron density, (2) a new model for the topside ion composition, (3) the first-time inclusion of a model for the spread F occurrence probability, (4) a NeuralNet model for auroral E-region electron densities, (5) a model for the plasmaspheric electron temperature, and (6) the latest International Geomagnetic Reference Field (IGRF) model for the computation of magnetic coordinates including their changes due to the secular variation of the magnetic field.