cssi/SciSciGPT-SciSciNet huggingface dataset:
Air temperatures over-predict changes to stream fish assemblages with climate warming compared with water temperatures.

Studies predicting how the distribution of aquatic organisms will shift with climate change often use projected increases in air temperature or water temperature. However, the assumed correlations between water temperature change and air temperature change can be problematic, especially for mountainous, high elevation streams. Using stream fish assemblage data from 1,442 surveys across a mountain-plains gradient (Wyoming, USA; 1990-2018), we compared the responsiveness of thermal guilds, native status groups, and assemblage structure to projected climate warming from generalized air temperature models and stream-specific water temperature models. Air temperature models consistently predicted greater range shift differences between warm-water and cold-water species, with air temperatures predicting greater increases in occurrence and greater range expansions for warm-water species. The "over-prediction" of warm-water species expansions resulted in air temperature models predicting higher rates of novel species combinations, greater increases in local species richness, and higher magnitudes of biotic homogenization compared with water temperature models. Despite differences in model predictions for warm-water species, both air and water temperature models predicted that three cold-water species would exhibit similar decreases in occurrence (decline of 1.0% and 1.8% of sites per 1°C warming, respectively) and similar range contractions (16.6 and 21.5 m elevation loss per 1°C warming, respectively). The "over-prediction" for warm-water species is partially attributable to water temperatures warming at slower rates than air temperatures because local, stream-scale factors (e.g., riparian cover, groundwater inputs) buffer high elevation streams from rising air temperatures. Our study provides the first comparison of how inferences about climate-induced biotic change at the species- and assemblage-levels differ when modeling with generalized air temperatures versus stream-specific water temperatures. We recommend that future studies use stream-specific water temperature models, especially for mountainous, high elevation streams, to avoid the "over-prediction" of biotic changes observed from air temperature variables.
SU-E-J-76: CBCT Reconstruction of a Full Couch Using Rigid Registration and Pre-Scanned Couch Image and Its Clinical Application

Purpose: Only a part of a treatment couch is reconstructed in CBCT due to the limited field of view (FOV). This often generates inaccurate results in the delivered dose evaluation with CBCT and more noise in the CBCT reconstruction. Full reconstruction of the couch at treatment setup can be used for more accurate exit beam dosimetry. The goal of this study is to develop a method to reconstruct a full treatment couch using a pre-scanned couch image and rigid registration. Methods: A full couch (Exact Couch, Varian) model image was reconstructed by rigidly registering and combining two sets of partial CBCT images. The full couch model includes three parts: two side rails and a couch top. A patient CBCT was reconstructed with reconstruction grid size larger than the physical field of view to include the full couch. The image quality of the couch is not good due to data truncation, but good enough to allow rigid registration of the couch. A composite CBCT image of the patient plus couch has been generated from the original reconstruction by replacing couch portion with the pre-acquired model couch, rigidly registered to the original scan. We evaluated the clinical usefulness of this method bymore » comparing treatment plans generated on the original and on the modified scans. Results: The full couch model could be attached to a patient CBCT image set via rigid image registration. Plan DVHs showed 1∼2% difference between plans with and without full couch modeling. Conclusion: The proposed method generated a full treatment couch CBCT model, which can be successfully registered to the original patient image. This method was also shown to be useful in generating more accurate dose distributions, by lowering 1∼2% dose in PTV and a few other critical organs. Part of this study is supported by NIH R01CA133539.« less
The design of exact nonlinear model followers

A practical approach to the design of control systems for strongly nonlinear, multivariable, time-dependent plants is described. The structure of the control system is that of an exact model follower. The model dynamics are decoupled, linear, constant, and of the order of the plant. The plant state and controls are transformed so that the plant, when viewed through these transformations, looks like the simple model. Regulation of disturbances is accomplished by means of the transformed state and controls. Conditions for transformability into linear models, the appropriate models, and the construction of the transformations are discussed. The approach is illustrated on a trajectory autopilot for a helicopter.
The Strictly Newtonian Mechanics Problem

In this section we define with some precision the problem of classical particle mechanics. As observed in Section 2.3, Newtonian systems have been divided into those called “strictly Newtonian” (SN), in which impulsive forces are excluded, and those called “Newtonian” (N), in which unbounded forces of bounded impulse are admitted. The strictly Newtonian systems are the more common; they are the ones on which a first course in dynamics is usually centered. Thus, we begin with formulation of (SN). Systems (N) which are not (SN) will be treated later in a chapter on impulsive motion (see Chapter 21).
Seasonal decline in plant defence is associated with relaxed offensive oviposition behaviour in the viburnum leaf beetle Pyrrhalta viburni

1. Plant defence of Viburnum shrubs against oviposition by its specialist herbivore, the viburnum leaf beetle [VLB Pyrrhalta viburni(Paykull)], involves an egg-crushing wound response in twigs. Although the response is variable among Viburnum species, it can have a strong impact on egg survivorship. Beetles typically aggregate egg masses with conspecifics along infested twigs, forming clusters that can overwhelm the twig response. It was investigated whether twig responses and beetle oviposition behaviour vary seasonally. 2. In a field experiment, twig defences decreased towards the end of the VLB oviposition period: wound response of the North American Viburnum dentatum L. and the European V. opulus L. was reduced by 100% and 54%, respectively, in September compared with the July to August period. 3. Oviposition trials demonstrated a corresponding behavioural change: VLB females displayed aggregative oviposition in August, but not in September. 4. Further tests revealed that late-season VLB females reverted to aggregative oviposition after being kept on uninfested twigs, whereas females kept on heavily infested twigs did not. This behavioural change suggests that relaxation of aggregative oviposition originates from cues associated with high densities of egg masses. 5. Relaxation of aggregative oviposition may be adaptive (and beneficial for invasion) on shrubs with low levels of defences by reducing intra-specific competition.
Protein deprivation alters trafficking of the B cell receptor and endogenous antigens in B cells (APP3P.106)

Protein malnutrition in children has been linked to increased instance of infection and higher fatality likely due to limited T and B cell-mediated host immunity. These findings suggest protein malnourishment may alter antigen presentation and the cognate interaction between T and B cells. Studies here show serum deprivation induced macroauophagy and MHC class II presentation of select antigens which utilize this pathway in B cells. Further studies established serum deprivation inhibited MHC class II presentation of cytoplasmic autoantigen, glutamic acid decarboxylase and the presentation of epitopes derived from the B cell receptor. Serum deprivation did not alter the expression MHC class II proteins but did upregulate proteasome and lysosomal protease activity. Interestingly, B cell receptor accumulation on the cell surface was detected likely due to a reduction in endocytosis. An altered subcellular distribution of glutamic acid decarboxylase protein was observed, suggesting changes in the trafficking of this antigen. Studies are currently underway to examine how protein deprivation regulates antigen trafficking and presentation. This work was supported by the T32DK007519 and NIH RO1AI079065.
Memes as Signs in the Dynamic Logic of Semiosis: Beyond Molecular Science and Computation Theory

The concept of meme misidentifies units of cultural information as active agents, which is the same “shorthand” that misleads our understanding of genes and obscures the dynamic logic of evolution. But the meme concept does offer hope by contributing something missing from many semiotic theories. In treating memes as replicators, Dawkins fails to distinguish mere patterns from information (and replication from interpretation), which leads to the problem encountered in all realms of information processing: what counts as information is context dependent. Nothing is intrinsically meaningful, to be so it must be interpreted. In the evolution of both genes and words, replication has always been a multilevel affair in a dynamic system, from which what we conceive as “adapted” or “interpreted” units emerge. Memes are replicas not replicators, and I suggest that the iconic function of signs, as identified by Peirce, is the essence of the meme concept. As in sign function, both gene and meme functions are informed by whatever relationship exists between the physical pattern of the token and the system of processes in which each is embedded (so these are semiotic relationships). I argue that two, not-clearly-articulated aspects of the meme concept could rescue semiotic from mere descriptive taxonomy and lead the way for a general theory of semiosis and a unifying methodology for the semiotic sciences to emerge.
Nomalike lesion in a patient with chronic lymphocytic leukemia: Review of the literature and report of a case

A case in which a nomalike lesion occurred in a patient being treated for chronic lymphocytic leukemia has been reported. Differential diagnosis of noma from other oral gangrenous processes has been described. The pathophysiology of systemic disease and blood dyscrasias contributing to the development of the lesion has been discussed with reference to management and treatment. A review of the literature is included.
Fetal immunoglobulin synthesis following maternal immunosuppression.

Abstract Cord blood levels of immunoglobulin (Ig) A, IgM, IgD, and IgG classes and IgA 1 and IgA 2 subclasses were determined in the offspring of seven mothers who received azathioprine and/or prednisone during the entire pregnancy. Five of these women received the immunosuppressive therapy following kidney transplantation, and two received immunosuppressive therapy because of disseminated systemic lupus erythematosus. The fetuses appeared to have intact humeral immune function in that they had normal cord blood immunoglobulin concentrations and in one case responsded with increased synthesis of IgA and IgM following premature rupture of the membranes.
Multiferroic magnetoelectric nanostructures for novel device applications

Multiferroic magnetoelectric nanostructures with coupled magnetization and electric polarization across their interfaces have stimulated intense research activities over the past decade. Such interface-based magnetoelectric coupling can be exploited to significantly improve the performance of many devices such as memories, tunable radio-frequency/microwave devices, and magnetic sensors. In this article, we introduce a number of current or developing technologies and discuss their limitations. We describe how the use of magnetoelectric nanostructures can overcome these limitations to optimize device performance. We also present challenges that need to be addressed in pursuing practical applications of magnetoelectric devices.
Histone demethylation and acetylation are involved in the epigenetic regulation of epithelial-mesenchymal transition (EMT)

Epithelial-Mesenchymal transition is an important process in the repair and maintenance of the epithelial barrier in the lungs. During EMT epithelial cells gain increased motility and increased production of proteins, such as collagen and actin. EMT is important in a number of lung diseases, and is associated with fibrosis in asthma, remodeling in COPD and increased metastasis and invasiveness in lung cancer. Epigenetic regulation including post-translational modifications of histones is thought to play an important role in gene regulation and cell differentiation. Histone modifications such as acetylation and methylation are recognized by transcriptional co-factors such as Brd4 and JMJD3. We used type 1, alpha 1, collagen, encoded by the gene COL1A1 , as a marker of the EMT process normal human bronchial epithelial cells. Stimulation with TGFβ1 strongly induced COL1A1 transcription. Pretreating epithelial cells with the H3K27 demethylase JMJD3 inhibitors (GSKJ1 and GSKJ4) and the Brd4 inhibitor (JQ1) significantly inhibited TGFβ1 induced collagen expression. Our results indicate that following stimulation of epithelial cells with TGFβ1 the histones in the COL1A1 promoter region are demethylated by JMJD3 allowing transcriptional activation. As Brd4 recognizes changes to histone acetylation our results indicate that during EMT the histones of the COL1A1 promoter become acetylated. Therefore epigenetic modification of histones plays a key role during the process of TGFβ1 induced EMT.
Effect of low-dose testicular irradiation on sperm count and fertility in patients with testicular seminoma.

The treatment of seminoma with radiation therapy risks transient infertility. We have prospectively followed eight patients with stage I seminoma of the testicle. All patients underwent radical orchiectomy of the affected testis. The mean age of the patients was 32.9 years (range 24-40). Each patient was treated with megavol- tage radiation with a 10- or 18-MV linear accelerator. The remaining testicle was shielded using a standard lead enclosure, and the mean testicular dose was 44 cGy (range 20.8-78.2). Semen specimens were delivered to the lab within 30 minutes of ejaculation. All spec- imens were analyzed using a computer-assisted sperm analyzer. Pretreatment parameters were within normal limits for all but one patient; one patient presented with a borderline normal sperm count at 18 and 22 x 10#{176}/mI. Following treatment, there was a decrease in sperm count, detected at 3 months, to <10 x 10#{176}/mi (range 4.4- 8.6 x 106) in all patients except one, who presented with an initial pretreatment count of 189 x 10#{176}/mI, which decreased to 58 x 10#{176}/ ml at 3 months, 32 x 10#{176}/mI at 6 months, and rose to 325 x 106/ ml by 12 months following treatment. Although the sperm count for this patient (D.L.) was within the normal range, the post-radiation sperm count was less than 20% of the pretreatment count. There was no difference in the motility at 3 months, the mean of which was 51.3%. One patient's (F.C.) wife conceived at 9 months following treatment, one at 12 months (J.R.), and one (J.S.) at 14 months, and all have delivered normal infants. Of the remaining patients, four patients recovered sperm counts within the normal range by 1 year (range 38-325 x 10#{176}/mI), one by 18 months, and one by 30 months. Of the two remaining patients, one did not return for sperm analysis after the couple had a child using banked sperm, and the second was able to conceive a child at 14 months and believed that a sperm count was superfluous. The earliest recovery was seen at 12 months. In the present study, recovery was seen at doses of �65 cGy, although the one patient receiving a dose of 90 cGy conceived nat- urally and did not return for follow-up sperm analysis after a sperm
Polyadenylylation in copia requires unusually distant upstream sequences.

Abstract Retroviruses and related genetic elements generate terminally redundant RNA products by differential polyadenylylation within a long terminal repeat. Expression of the white-apricot (wa) allele of Drosophila melanogaster, which carries an insertion of the 5.1-kilobase retrovirus-like transposable element copia in a small intron, is influenced by signals within copia. By using this indicator, we have isolated a 518-base-pair deletion, 312 base pairs upstream of the copia polyadenylylation site, that is phenotypically like much larger deletions and eliminates RNA species polyadenylylated in copia. This requirement of distant upstream sequences for copia polyadenylylation has implications for the expression of many genetic elements bearing long terminal repeats.
A Confirmatory Factor Analytic Study Examining the Dimensionality of the Raven'S Advanced Progressive Matrices

The objective of the current study was to provide a direct comparison of two competing views of the underlying structure of the Raven's Advanced Progressive Matrices (APM), a widely used test designed as a nonverbal measure of general cognitive ability (g). The first view postulates a two-factor model to explain the structure of the APM; and the second view, a single-factor model. The results of a confirmatory factor analysis suggest that a single-factor solution seems to be the best representation of the APM's structure. These findings are also consistent with the original development and intended use of the APM as a measure of a unidimensional construct.
Effect of gut transposition on the expression of the endocrine gene neurotensin

Expression of the gene encoding neurotensin (NT/N) is developmentally regulated in the adult small bowel with maximal expression noted in the distal ileum; the mechanisms responsible for this strict spatial-specific expression pattern are not known. The purpose of this study was to determine whether NT/N expression is altered by ileojejunal transposition. Rats underwent either sham operation or ileojejunal transposition and were killed 2 months after operation. The transposed (either jejunum or ileum) and sham-operated segments of gut were removed, a portion was processed for histologic examination, and the remainder was extracted for total RNA and analyzed by ribonuclease protection using a rat NT/N probe. For comparison, expression of another gut endocrine gene, peptide YY, and an enterocyte-specific gene, sucrase-isomaltase (SI), was also determined. Expression of the gut endocrine genes, NT/N and peptide YY, were minimally affected by transposition of either the jejunum or ileum. In contrast, SI expression was markedly altered in both the transposed jejunum and ileum compared with corresponding sham gut segments. Expression of the NT/N gene is minimally altered after jejunoileal transposition despite marked adaptive and morphologic changes in the transposed segments. These findings provide further support that the strict pattern of NT/N expression is “imprinted” in the gut and maintained regardless of location along the cephalocaudal gut axis.
The problem of iconicity

Abstract The problem of iconicity involves a critique of de Saussure's principle of the arbitrariness of the linguistic sign. De Saussure himself admitted that the linguistic system is relatively motivated or limited in its arbitrariness. The salient question for iconicity is similarity: both the similarity between the signifier and the signified, and similarity within the context of the linguistic system. Both Peirce's and Jakobson's definitions of iconicity point to this question of similarity. In Peirce's system, the three subtypes of icon: images, diagrams, and metaphors, all involve a relation of similarity. In Jakobson's system, with its roots in the linguistic theory of Mikolaj Kruszewski, the two axes of language are those of contiguity and similarity, corresponding to arbitrariness and iconicity; Jakobson also termed these the axes of metonymy and metaphor. The iconic nature of metaphor involves a latent similarity of parallelism toward which the metaphor points, which can be interpreted, and which is beheld as an image in the mind's eye. Thus, metaphor is both the most abstract and the most concrete instance of iconicity, and is a bridge between language and the world.
The long-term culture of a diploid rat hepatocyte cell strain.

We have developed a cell culture system of cloned rat hepatocytes which is named RL-PR-C. This culture has been grown in culture for over 150 passages (560 p.d.). It remains diploid by modal number count for over 50 passages (183 p.d.) after which there is a variation in the modal number between 41 and 42. The culture becomes intrinsically (spontaneously) malignantly transformed at about this time whereas cells treated with aflatoxin B1, at subacute and subtoxic doses, from Passage 12(65 p.d.) were malignantly transformed at Passage 35(135 p.d.). Evidence indicates that not all cells in the population are malignantly transformed. Back injection of mixed population of malignantly transformed cells into isogenic rat pups, yield tumors which are histologically classified as mixed. That is, areas of the same tissue slice exhibit both carcinomas and sarcoma characteristics. Data obtained by injection of clones derived from malignantly transformed cells suggest that the cells injected are multipotent with respect to the type of tumor formed. Further investigations are continuing in this regard. This cultural system will be used to study the evolution and maintenance of the transformed state and to develop a test system for putative carcinogens and mutagens.
“Do You Think Hearing Loss in Aging is Normal? Think Again!”

Older adults with hearing loss may not receive the necessary and appropriate referral and follow-up services, if the individuals involved with their care believe that hearing loss is simply a normal consequence of aging. While hearing loss may be “common” in older adults, it is by no means “normal” and brings with it consequences that can affect older individuals from a communicative and a psychosocial standpoint. This article will review types of hearing loss, some causes of hearing loss in older people, and the importance of evaluation and appropriate rehabilitative management of older individuals with hearing loss.
Evolution since z = 1 of the Morphology-Density Relation for Galaxies

We measure the morphology-density relation of galaxies at z = 1 across the full 3 orders of magnitude in projected galaxy density available in low-redshift studies. Our study adopts techniques that are comparable with those applied at lower redshifts, allowing a direct investigation of how the morphological segregation of galaxies has evolved over the last 8 Gyr. Although the morphology-density relation, as described by the fraction of early-type (E+S0) galaxies, was in place at z = 1, its form differs from that observed at both z = 0 and z = 0.5. In the highest density regions the early-type fraction has increased steadily with time from fE+S0 = 0.7 ± 0.1 at z = 1 to fE+S0 = 0.9 ± 0.1 at the present epoch. However, in intermediate-density regions corresponding to groups and the accretion regions of rich clusters, significant evolution appears to begin only after z = 0.5. Finally, at the lowest densities, no evolution is observed for the early-type fraction of field galaxies, which remains constant at fE+S0 = 0.4 ± 0.1 at all epochs. We examine a simple picture consistent with these observations where the early-type population at z = 1 is comprised largely of elliptical galaxies. Subsequent evolution in both intermediate and dense regions is attributed to the transformation of spirals into lenticulars. Further progress in verifying our hypothesis may be achieved through distinguishing ellipticals and lenticulars at these redshifts through resolved dynamical studies of representative systems.
Do Certification Seals Permit a Price Premium for Online Security and Privacy

If some consumers care more about online privacy and security than others, and if providing privacy and security imposes opportunity costs on firms, then firms with more privacy and security measures should charge higher prices, and consumers who value these measures should be willing to pay higher prices. To test this hypothesis, data on the prices and certification seals of websites were collected. Examination of the data reveals moderate evidence that firms with a specific kind of security seal enjoy a price premium, and no evidence that sites displaying other seals enjoy a price premium. These findings suggest either that regulation may be unnecessary because markets are correctly pricing security and privacy, or that there is a market failure preventing privacy certification seals from providing credible signals to consumers.
Learning Leadership Skills in Elementary School

AbstractLeadership is everyone's responsibility—even first graders. The most important contribution that any educator can make in an era of unrelenting change is identifying and developing aspiring leaders. Elementary school teachers can embed leadership development opportunities into the classroom to foster leadership dispositions and skills grounded in the spirit to include, the passion to serve, the courage to question, and the discipline to listen. Four leadership dispositions illustrate a framework for identifying and developing aspiring elementary school leaders.
Generation of 3‐D finite‐difference time‐domain macromodels for faster simulation

Computing time in finite-difference time-domain can be saved by expressing a portion of the grid (macromodel) as an linear time invariant (LTI) system. The output then becomes a convolution of the input with the LTI impulse response. To achieve a constant time for the convolution, the macromodel's response is expressed as a superposition of eigenmodal frequencies. That time is reduced by discarding nonessential eigenmodes. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007.
Theory and Practice of Immunoregulation by Tissue Treatment Prior to Transplantation

According to the classical view of allograft rejection, the transplanted tissue is the source of antigen that stimulates a T-cell response, which in turn sets up the rejection process. Research now indicates that two signals are required for lymphocyte activation. The first signal is provided by antigen binding by the T-cell receptor. A stimulator cell provides an inductive molecule, costimulator activity, which is the second signal. The stimulator cell model of lymphocyte activation has resulted in a new passenger leukocyte concept, in which these passenger cells are seen to play a central role in graft rejection. Appropriate treatment of a tissue prior to transplantation can afford a marked reduction in its immunogenicity for the host. It is now possible to eliminate or at least reduce tissue immuno-genicity by removal of leukocytes from the transplant prior to grafting. This phenomenon has been demonstrated to be effective with both endocrine tissue and larger organs, such as the kidney. There is some variation in the effectiveness of the technique with different tissues which can be related to the degree of leukocyte contamination. Allografts of pretreated tissue can induce a state of specific unresponsiveness in the adult recipient. Although the mechanism of this tolerance is not fully understood, the existence of the phenomenon is one of the most encouraging recent developments in transplantation biology.
An intracellular study of the myocadial cells of the flesh fly, Sarcophaga bullata

Abstract 1. 1. The myocardial cells of the flesh fly, Sarcophaga bullata , have been studied using conventional micro-electrode techniques. These studies indicated that an initial period of aertation or oxygenation was necessary to maintain the heart. 2. 2. The range of values, for the action and resting potential were 45 ± 8 mV and 57 ± 11 mV respectively with negligible or no overshoot. 3. 3. These studies indicate that the intracellular potentials from the myocardial cells of the flesh fly can vary in amplitude, rate and duration from cell to cell and within the same cell. 4. 4. The wave form is complex and commonly shows pacemaker characteristics as well as fast spikes which suggests a neural involvement.
Automated Service Composition and Routing in Networks with Data-Path Services

Advanced packet processing in the data path of networks is common in the current Internet and is expanding to next-generation networks. Dynamic composition of such “network services” allows networks to establish connections with customized communication characteristics to satisfy various application requirements. In these networks, there are two problems that need to be solved: finding the optimal composition of services to satisfy the communication requirements of a given connection (“service composition”) and finding the optimal path for a given composition of services such that the required services are executed in sequence along the path (“service routing”). So far, these two problems have been studied separately. In our work, we combine both into a “service composition and routing” approach that can achieve better solutions than the current, separate approach. We present a novel decision making system that can determine the optimal or near-optimal solutions for the service composition and routing problem. We develop a synthetic benchmark for service requests to help comprehensively evaluate the performance of our systems. The results show that considering service composition and service routing jointly results in connections that have lower end-to-end delay while still meeting all service requirements.
On the Characterization of Strain-Hardening in Plasticity.

Abstract : In the context of a purely mechanical, rate-type theory of elastic-plastic materials and utilizing a strain space formulation, this paper is concerned mainly with developments pertaining to strain-hardening behavior consisting of three distinct types of material response, namely hardening, softening and perfectly plastic behavior. It is shown that such strain-hardening behavior may be characterized by a rate-independent quotient of quantities occurring in the loading criteria of strain space and the corresponding loading conditions of stress space. With the use of special constitutive equations, the predictive capability of the results obtained are illustrated for strain-hardening response and saturation hardening in a uniaxial tension test.
The unwed adolescent father's perceptions of his family and of himself as a father

The study reported in this paper investigated how an adolescent father's relationship with his family of origin affects his relationship with his own child. The dependent variable was parental behavior. The adolescent father's perceived role conceptions of his parents and his feeling and attitudes toward his family were the independent variables. The study included a non-random sample of 43 African-American unwed adolescent fathers. The findings of the study indicated a father's parental behavior was influenced by his perceived role conceptions of his mother and his feelings and attitudes toward his family of origin.
Photoacoustic imaging of prostate brachytherapy seeds in ex vivo prostate

The localization of brachytherapy seeds in relation to the prostate is a key step in intraoperative treatment planning (ITP) for improving outcomes in prostate cancer patients treated with low dose rate prostate brachytherapy. Transrectal ultrasound (TRUS) has traditionally been the modality of choice to guide the prostate brachytherapy procedure due to its relatively low cost and apparent ease of use. However, TRUS is unable to visualize seeds well, precluding ITP and producing suboptimal results. While other modalities such as X-ray and magnetic resonance imaging have been investigated to localize seeds in relation to the prostate, photoacoustic imaging has become an emerging and promising modality to solve this challenge. Moreover, photoacoustic imaging may be more practical in the clinical setting compared to other methods since it adds little additional equipment to the ultrasound system already adopted in procedure today, reducing cost and simplifying engineering steps. In this paper, we demonstrate the latest efforts of localizing prostate brachytherapy seeds using photoacoustic imaging, including visualization of multiple seeds in actual prostate tissue. Although there are still several challenges to be met before photoacoustic imaging can be used in the operating room, we are pleased to present the current progress in this effort.
Spin densities and form factors: Past, present, and future☆

Abstract The development of polarized neutron diffraction as a standard method for the study of magnetic moment densities was largely due to the efforts of C.G. Shull. The early experiments by Shull, his students, and co-workers are reviewed. A comparison of his early results on the magnetic form factor of Fe with very recent theoretical work is presented and excellent agreement is found. Some more recent experimental results are described to illustrate the many types of magnetic systems to which this technique has been applied. Brief speculations about future directions are offered.
Cell proliferation after ischemic injury in gerbil brain. An immunocytochemical and autoradiographic study.

Tritiated thymidine autoradiography was used to measure cellular proliferation after ischemic injury in gerbil brain. Gerbils were subjected to bilateral occlusion of the common carotid arteries which resulted in areas of necrosis, or infarcts, in the posterior thalamus or midbrain. From 12 h to 10 days following the ischemia, gerbils were injected with 3H thymidine, sacrificed 4 h later, and the brains sectioned. In order to identify astrocytes and monocytes/macrophages, immunocytochemistry was performed prior to autoradiography, using antisera against glial fibrillary acidic protein and endothelial-monocyte reticuloendothelial antigen, respectively. Immunocytochemistry was also used to visualize microvessel laminin, myelin, and leakage of serum albumin. Lastly, a histochemical procedure for acid phosphatase activity was employed to verify cellular phagocytic activity in the wound. A reproducible sequence of reactions took place during the first 10 days after ischemia. Early changes included leakage of albumin and myelin breakdown, followed by arrival of monocytes at 2 days and their differentiation into macrophages by 5 days. These cells exhibited intense proliferation from 2 to 6 days post-ischemia. Microvessel endothelial cells were maximally labeled at 4 days post-ischemia. Hypertrophied astrocytes were apparent at 2 days and proliferated from 3 to 7 days post-ischemia, and by 10 days the wound was replaced by a “glial scar”.
Modeling day-to-day ionospheric variability on Mars

[1] We use a simple photochemical model of Mars' ionosphere to investigate the changes in calculated electron density profiles, Ne(h), under the assumption that the only variable parameter is the solar irradiance. The period under study is 9–27 March 1999, corresponding to a series of Ne(h) observations made by the Mars Global Surveyor (MGS) Radio Science (RS) experiment. The SOLAR 2000 model is used to obtain the solar irradiances during this period. Secondary ionization is included and is expressed as a simple function of photoionization. The model uses several neutral gas species, five of which (CO2, N2, CO, NO, O) experience photoionization. Subsequent ion-neutral chemistry leads to an ionosphere with five ions species. Using average solar conditions for March 1999, good agreement was obtained between the model's mean electron density profile and the mean electron densities from the MGS observations. Modeling day-to-day changes using daily solar irradiance values resulted in ∼6% and 19% variabilities for the major and secondary layer peak densities, respectively, in good agreement with the observed values of 5 and 10%. The variable photon flux from the Sun is thus the primary driver of day-to-day changes in the peak electron densities on Mars.
The standard molar enthalpy of formation of liquid hydrogen fluoride ΔfHom(HF, l) at the temperature 298.15 K determined by direct combination of the elements in a fluorine-bomb calorimeter

Abstract The standard molar enthalpy of formation of liquid hydrogen fluoride ΔfHom (HF, l) = -(303.56 ± 0.27) kJ·mol-1 at T = 298.15 K and po = 101.325 kPa has been measured by direct reaction of gaseous hydrogen and fluorine in a bomb calorimeter. This result, combined with the standard molar enthalpy of solution ΔsolHom(HF, l) reported by Johnson et al. (J. Chem. Thermodynamics1973, 5, 793) gives the standard molar enthalpy of formation of F-(aq) at infinite dilution: ΔfH(F-, aq, 298.15 K) = -(335.66 ± 0.31) kJ·mol-1.
An indirect solid-phase microradioimmunoassay for human IgM-anti-IgG (rheumatoid factor)

In order to satisfy the general need for a more precise measurement of the serum concentration of rheumatoid factor (RF) than is presently obtainable with the latex test, we developed a rapid indirect solid phase micro radioimmunoassay for RF determination. The assay involves the binding of IgM-anti IgG (RF), to the polyclonal, native or denatured human IgG dried on the bottom surface of microtiter plates; the amount of antiglobulin bound is then determined by adding 125I-labelled goat anti-human IgM (125I-AHIgM). Variations of reagents and their concentrations, temperatures and incubation times were studied to find the optimal conditions for test sensitivity, specificity and reproducibility. The test has a within day and between day average coefficient of variation of 9 and 15% respectively, showing its advantages over the latex test. The results obtained by studying 100 human sera from patients with positive or negative latex test show that the test should prove valuable in diagnosis and research.
Borrowed Gods and Foreign Bodies: Christian Missionaries Imagine Chinese Religion

Borrowed Gods and Foreign Bodies: Christian Missionaries Imagine Chinese Religion. By Eric Reinders. Berkeley: University of California Press, 2004. 283 pp, Bilbi. ISBN 0-5202-4171-1. $40.95 (cloth).
Epoxy-based broadband antireflection coating for millimeter-wave optics

We have developed epoxy-based, broadband antireflection coatings for millimeter-wave astrophysics experiments with cryogenic optics. By using multiple-layer coatings where each layer steps in dielectric constant, we achieved low reflection over a wide bandwidth. We suppressed the reflection from an alumina disk to 10% over fractional bandwidths of 92% and 104% using two-layer and three-layer coatings, respectively. The dielectric constants of epoxies were tuned between 2.06 and 7.44 by mixing three types of epoxy and doping with strontium titanate powder required for the high dielectric mixtures. At 140 K, the band-integrated absorption loss in the coatings was suppressed to less than 1% for the two-layer coating, and below 10% for the three-layer coating.
Cross-bridge kinetics in the presence of MgADP investigated by photolysis of caged ATP in rabbit psoas muscle fibres.

1. The interaction between MgADP and rigor cross-bridges in glycerol-extracted single fibres from rabbit psoas muscle has been investigated using laser pulse photolysis of caged ATP (P3-1(2-nitrophenyl)ethyladenosine 5'-triphosphate) in the presence of MgADP and following small length changes applied to the rigor fibre. 2. Addition of 465 microM-MgADP to a rigor fibre caused rigor tension to decrease by 15.3 +/- 0.7% (S.E.M., n = 24 trials in thirteen fibres). The half-saturation value for this tension reduction was 18 +/- 4 microM (n = 23, thirteen fibres). 3. Relaxation from rigor by photolysis of caged ATP in the absence of Ca2+ was markedly slowed by inclusion of 20 microM-2 mM-MgADP in the photolysis medium. 4. Four phases of tension relaxation occurred with MgADP in the medium: at, a quick partial relaxation (in pre-stretch fibres); bt, a slowing of relaxation or a rise in tension for 50-100 ms; ct, a sudden acceleration of relaxation; and dt, a final, nearly exponential relaxation. 5. Experiments at varied MgATP and MgADP concentrations suggested that phase at is due to MgATP binding to nucleotide-free cross-bridges. 6. Phase bt was abbreviated by including 1-20 mM-orthophosphate (Pi) in the photolysis medium, or by applying quick stretches before photolysis or during phase bt. These results suggest that phases bt and ct are complex processes involving ADP dissociation, cross-bridge reattachment and co-operative detachment involving filament sliding and the Ca(2+)-regulatory system. 7. Stretching relaxed muscle fibres to 3.2-3.4 microns striation spacing followed by ATP removal and release of the rigor fibre until tension fell below the relaxed level allowed investigation of the strain dependence of relaxation in the regions of negative cross-bridge strain. In the presence of 50 microM-2 mM-MgADP and either 10 mM-Pi or 20 mM-2,3-butanedione monoxime, relaxation following photolysis of caged ATP was 6- to 8-fold faster for negatively strained cross-bridges than for positively strained ones. This marked strain dependence of cross-bridge detachment is predicted from the model of A. F. Huxley (1957). 8. In the presence of Ca2+, activation of contraction following photolysis of caged ATP was slowed by inclusion of 20-500 microM-MgADP in the medium. An initial decrease in tension related to cross-bridge detachment by MgATP was markedly suppressed in the presence of MgADP. 9. Ten millimolar Pi partly suppressed active tension generation in the presence of MgADP.(ABSTRACT TRUNCATED AT 400 WORDS)
Laser steering of particle beams: refraction and reflection of particle beams

The co-propagation of an intense particle beam with an ionizing laser beam in a working gas/plasma is considered. When the axes of the laser and particle beam are not aligned, then asymmetric plasma lensing results in a net dipole field acting on the particle beam. The particle beam can be steered or bent (as well as focused) by steering the laser. An analogy is made between the bending of the particle beam by collective effects at a plasma boundary and the refraction or reflection of light at an interface. This mechanism of particle steering may be of interest in applications for which permanent magnets are inconvenient of a fast turn on is required. 3-D particle-in-cell simulations and relevance to a recent experiment are discussed.
Migration and Racial Formations Among Somali Immigrants in North America

Early writers on migrants in North America such as Bryce-Laporte (1972) lamented the lack of research on black immigrants, referring to them as invisible immigrants. Since then, both the volume of research on foreign-born blacks as well as their share of the overall black population in North America have risen dramatically. This increase signals that the black population in North America is a diverse group increasingly identifying themselves more by culture and/or nationality than by skin colour. Using qualitative research methods, this project focuses on the disjuncture between how one set of black immigrants—Somalis—understand blackness in their homelands and how it is defined in North America. The findings reveal the problematics of racial categories and confirm the situational nature of racial identities. The results of this study are not substantially confined to African immigrants alone, but carry both theoretical and conceptual significance for the development, maintenance and consequences of racia...
Nitration of distinct tyrosine residues causes inactivation of histone deacetylase 2

Histone deacetylases (HDACs) are key molecules involved in epigenetic regulation of gene expression. We have previously demonstrated that oxidative stress caused a reduction in HDAC2, resulting in amplified inflammation and reduced corticosteroid responsiveness. Here we showed nitrative/oxidative stress reduced HDAC2 expression via nitration of distinct tyrosine residues. Peroxynitrite, hydrogen peroxide and cigarette smoke-conditioned medium reduced HDAC2 expression in A549 epithelial cells in vitro. This reduction was due to increased proteasomal degradation following ubiquitination rather than reduction of mRNA expression or stability. HDAC2 was nitrated under nitrative/oxidative stress and in the peripheral lung tissues of smokers and patients with chronic obstructive pulmonary disease. Mutagenesis studies replacing tyrosine (Y) residues with alanine revealed that Y253 is at least partly responsible for the proteasomal degradation of HDAC2 under nitrative stress. Thus, nitration of distinct tyrosine residues modifies both the expression and activity of HDAC2, having an impact on epigenetic regulation.
Giant gemini surfactants based on polystyrene–hydrophilic polyhedral oligomeric silsesquioxane shape amphiphiles: sequential “click” chemistry and solution self-assembly

This paper reports our recent investigations in the synthesis, characterization, and solution self-assembly of giant gemini surfactants consisting of two hydrophilic carboxylic acid-functionalized polyhedral oligomeric silsesquioxane (APOSS) heads and two hydrophobic polystyrene (PS) tails covalently linked via a rigid spacer (p-phenylene or biphenylene) (PS–(APOSS)2–PS). The sequential “click” approach was employed in the synthesis, which involved thiol–ene mono-functionalization of vinyl-functionalized POSS, Cu(I)-catalyzed Huisgen [3 + 2] azide–alkyne cycloadditions for “grafting” polymer tails onto the POSS cages, and subsequent thiol–ene “click” surface functionalization. The study of their self-assembly in solution revealed a morphological transition from vesicles to wormlike cylinders and further to spheres as the degree of ionization of the carboxylic acid groups on POSS heads increases. It was found that the PS tails are generally less stretched in the micellar cores of these giant gemini surfactants than those of the corresponding single-tailed (APOSS–PS) giant surfactant. It was further observed that the PS tail conformations in the micelles were also affected by the length of the rigid spacers where the one with longer spacer exhibits even more stretched PS tail conformation. Both findings could be explained by the topological constraint imposed by the short rigid spacer in PS–(APOSS)2–PS gemini surfactants. This constraint effectively increases the local charge density and leads to an anisotropic head shape that requires a proper re-distribution of the APOSS heads on the micellar surface to minimize the total electrostatic repulsive free energy. The study expands the scope of giant molecular shape amphiphiles and has general implications in the basic physical principles underlying their solution self-assembly behaviors.
Induction of yeast mating pheromone a -factor by α cells

Saccharomyces cerevisiae cells of a and alpha mating types constitutively secrete cell-specific peptide mating pheromones. a-Factor is secreted by a cells and acts on alpha cells, while alpha-factor is secreted by alpha cells and acts on a cells. Confirming preliminary studies, we demonstrate here that cultures of a cells contain higher than constitutive levels of a-factor activity when grown with alpha cells or alpha-factor. This induction of a-factor may result from increased synthesis or increased secretion of a-factor, as opposed to modification or stabilization of preexisting a-factor, as part of the a cell response to alpha-factor, as an a ste2 mutant (which cannot respond to alpha-factor) is not induced by alpha-factor. In mixed cultures inoculated with equal numbers of a cells and alpha cells, a cells predominate by stationary phase. Thus, a series of sequential interactions between a and alpha cells may be involved in establishing optimal hormone concentrations and cell ratios for conjugation.