cssi/SciSciGPT-SciSciNet huggingface dataset:
Determining leaf nutrient concentrations in citrus trees using UAV imagery and machine learning

Nutrient assessment of plants, a key aspect of agricultural crop management and varietal development programs, traditionally is time demanding and labor-intensive. This study proposes a novel methodology to determine leaf nutrient concentrations of citrus trees by using unmanned aerial vehicle (UAV) multispectral imagery and artificial intelligence (AI). The study was conducted in four different citrus field trials, located in Highlands County and in Polk County, Florida, USA. In each location, trials contained either ‘Hamlin’ or ‘Valencia’ sweet orange scion grafted on more than 30 different rootstocks. Leaves were collected and analyzed in the laboratory to determine macro- and micronutrient concentration using traditional chemical methods. Spectral data from tree canopies were obtained in five different bands (red, green, blue, red edge and near-infrared wavelengths) using a UAV equipped with a multispectral camera. The estimation model was developed using a gradient boosting regression tree and evaluated using several metrics including mean absolute percentage error (MAPE), root mean square error, MAPE-coefficient of variance (CV) ratio and difference plot. This novel model determined macronutrients (nitrogen, phosphorus, potassium, magnesium, calcium and sulfur) with high precision (less than 9% and 17% average error for the ‘Hamlin’ and ‘Valencia’ trials, respectively) and micro-nutrients with moderate precision (less than 16% and 30% average error for ‘Hamlin’ and ‘Valencia’ trials, respectively). Overall, this UAV- and AI-based methodology was efficient to determine nutrient concentrations and generate nutrient maps in commercial citrus orchards and could be applied to other crop species.
Predicting Fetal Malnutrition

Human fetal malnutrition is associated with reduced neuroblast formation, cell numbers, myelin formation and dendritic arborization in the developing brain. Postnatally, neurologic defects and impaired mental development and school performance are common. Congenital anomalies are eight times more frequent and there is little or no catch-up growth of brain or stature. These all lead to net reduction of competitive competence in childhood and adult life. The cost of a society in terms of lost potential may be enoumous. Fetal malnutrition may compromise 5 – 8% of all pregnancies in developed countries like the U.S.A., and 9 – 28% of all live births with gestational period more than 37 weeks in developing countries. World wide, fetal malnutrition of the growing fetus and prevent the consequences of fetal malnutrition, prenatal diagnosis should identify those mothers carrying undernourished babies before the rapid phase of brain growth and cell hyperplasia is completed. If some constellation of nutrients and other remediable factors adversely affecting fetal growth can be identified at the same time, appropriate interventions could be initiated to improve intrauterine nutrition and growth of the fetus.
Detection and frequency estimation of narrow-band signals by means of the instantaneous-frequency distribution (IFD)

The instantaneous-frequency distribution (IFD) is an amplitude-invariant spectral representation applicable to signals such as speech. The performance of an IFD with time-averaging and squared-amplitude weighting as a narrow-band signal detector and frequency estimator, in comparison to the classical maximum-likelihood detector/estimator, is evaluated experimentally for a single-complex-pole Gaussian signal of known bandwidth but unknown center frequency, at known signal/noise ratio (SNR) in white Gaussian noise. It is concluded that the IFD is capable of detection and estimation performance approaching the theoretical optimum (i.e. that of maximum likelihood) to within the equivalent of a fraction of a dB degradation in SNR, at least over a range of signal bandwidths comparable to that of speech formants, for example. >
The Importance of IL-6 in the Development of LAT-Mediated Autoimmunity

Linker for activation of T cells (LAT) is a transmembrane adaptor protein that is highly tyrosine phosphorylated upon engagement of the TCR. Phosphorylated LAT binds Grb2, Gads, and phospholipase C (PLC)γ1 to mediate T cell activation, proliferation, and cytokine production. T cells from mice harboring a mutation at the PLCγ1 binding site of LAT (Y136F) have impaired calcium flux and Erk activation. Interestingly, these T cells are highly activated, resulting in the development of a lymphoproliferative syndrome in these mice. CD4(+) T cells in LATY136F mice are Th2 skewed, producing large amounts of IL-4. In this study, we showed that the LATY136F T cells could also overproduce IL-6 due to activated NF-κB, AKT, and p38 pathways. By crossing LATY136F mice with IL-6-deficient mice, we demonstrated that IL-6 is required for uncontrolled T cell expansion during the early stage of disease development. Reduced CD4(+) T cell expansion was not due to a further block in thymocyte development or an increase in the number of regulatory T cells, but was caused by reduction in cell survival. In aged IL-6(-/-) LATY136F mice, CD4(+) T cells began to hyperproliferate and induced splenomegaly; however, isotype switching and autoantibody production were diminished. Our data indicated that the LAT-PLCγ1 interaction is important for controlling IL-6 production by T cells and demonstrated a critical role of IL-6 in the development of this lymphoproliferative syndrome.
What Might A Stromal Response Mean to Prostate Cancer Progression

Many similarities exist between the stroma at sites of wound repair and reactive stroma in cancer. Common features include an elevated stromal cell proliferation, altered expression of matrix components, elevated expression of TGFβ-1, neovascularization, and expression of several common stromal markers. In addition, proliferative stromal cells at these sites generally express myodifferentiation markers. A comparison between the many common features and the biologically active molecules observed in reactive stroma in carcinoma and reactive stroma in wound repair is discussed in this review. An extended analysis of the literature suggests a functional link between mechanisms in wound repair response and the stromal reaction in many cancers including prostate cancer. We propose in this review, that the fundamental mechanisms of stroma in providing a rapid response to altered homeostasis in wounding, also provides for a tumor-regulating stromal microenvironment in cancer. The functional consequences of this stromal response to carcinoma progression and how the stromal response might be used in extended diagnosis and in therapeutic approaches are discussed.
A Review of: “Hollywood's White House: The American Presidency in Film and History”

Hollywood's White House: The American Presidency in Film and History is a most timely collection of essays. The decade of the 1990s witnessed a fundamental change in the motion picture business. Th...
K-Means with Large and Noisy Constraint Sets

We focus on the problem of clustering with soft instance-level constraints. Recently, the CVQE algorithm was proposed in this context. It modifies the objective function of traditional K-means to include penalties for violated constraints. CVQE was shown to efficiently produce high-quality clustering of UCI data. In this work, we examine the properties of CVQE and propose a modification that results in a more intuitive objective function, with lower computational complexity. We present our extensive experimentation, which provides insight into CVQE and shows that our new variant can dramatically improve clustering quality while reducing run time. We show its superiority in a large-scale surveillance scenario with noisy constraints.
Optimal pricing for a GI/M/k/N queue with several customer types and holding costs

This paper studies optimal pricing for a GI/M/k/N queueing system with several types of customers. An arrival joins the queue if the price of service is not higher than the maximum amount that the arrival is willing to pay, and this maximum amount is defined by the customer type. A system manager chooses a price depending on the number of customers in the system. In addition, the system incurs holding costs when there are customers waiting in the queue for their services. Service times and holding costs do not depend on customer types. The holding costs are nondecreasing and convex with respect to the number of customers in the queue. This paper describes average reward optimal, canonical, bias optimal, and Blackwell optimal policies for this pricing problem.
Clinical Relaxation Strategies

An Historical Perspective Theoretical Foundations Basic Research Deep Relaxation Methods Brief Relaxation Methods Relaxation Integrated with Other Treatments Clinical Outcome Research.
THROUGH A DIFFERENT LENS: USING FILM TO TEACH FAMILY LAW

This article discusses the aspects of narrative and character development that make films a useful tool to supplement classroom legal education. Moreover, utilizing film is particularly effective for learning and exploring the dynamics of human relationships at the center of family law cases. When designing a film and family law course instructors should seek to promote creative thinking, cultural competence, student exploration of bias and assumptions and best practices for attorneys based on the examples provided in the film. Films make the learning process more fun, but still provide substantial opportunities to broaden students' concept of the impact of law on family members.
Cardiac microdialysis in isolated rat hearts: interstitial purine metabolites during ischemia

Cardiac microdialysis is a recently developed technique that allows intramyocardial interstitial fluid (ISF) to be sampled via the implantation and perfusion of a small, hollow dialysis fiber within the myocardium. The purpose of this paper is to describe initial studies using cardiac microdialysis in the isolated perfused heart. Microdialysis probes, constructed in the laboratory, were implanted in the left ventricular myocardium of isolated perfused rat hearts and perfused at 0.5 microliter/min with Krebs-Henseleit buffer. The effluent dialysate, assayed for adenosine, inosine, hypoxanthine, xanthine, and uric acid, was used as an index of intramyocardial levels of these purine metabolites. All metabolites were elevated initially after implantation, declined rapidly in the first 45 min, and were then stable for the next 90 min. Based on in vitro percent recovery data, baseline dialysate concentrations were extrapolated to yield estimates of intramyocardial ISF (in microM) 0.47 adenosine, 0.85 inosine, 0.29 hypoxanthine, 0.49 xanthine, and 8.6 uric acid. During global zero-flow ischemia (37 degrees C), dialysate levels of all purine metabolites were elevated, with inosine being the predominant compound. Pretreatment of the hearts with 50 microM erythro-9-(2-hydroxy-3-nonyl)adenine, an adenosine deaminase inhibitor, markedly enhanced ISF adenosine accumulation and attenuated the accumulation of inosine, hypoxanthine, and xanthine. The simplicity and versatility of cardiac microdialysis in the isolated perfused heart suggest that this technique may be a valuable adjunct to the many studies performed using this preparation.
Ants of the Islas Murciélago: An Inventory of the Ants on Tropical Dry Forest Islands in Northwest Costa Rica

We conducted the first inventory of ants on the Islas Murcielago, Area de Conservacion Guanacaste (ACG) of Costa Rica. We conducted this study on a chain of seven islands and a nearby mainland site...
Learning from Experience: Recollections of Working with Howard S. Becker†

Howard S. Becker is, and has been, a major figure in contemporary sociology, especially within the symbolic interactionist perspective. This discussion describes my initial encounter with Howie in the mid-1960s and moves to identify the substantive and methodological areas in which he has had major impact. I then briefly outline various ways in which the foci of my own work have been shaped by Becker's instruction and example.
The impact of market requirements focus and manufacturing characteristics focus on plant performance

Abstract This study examines the relationship between market requirements focus, manufacturing characteristics focus, and manufacturing performance. Results from a sample of plants serving the automotive industry support the general argument that market requirements focus and manufacturing characteristics focus have an impact on manufacturing performance, and provide partial support for a mediation model of focus proposed by Bozarth (1993). The results also show that focused work cells or plants-within-a-plant might not be entirely successful at buffering plants from the negative impact of diverse market requirements.
Network Alignment Technique

A method is presented whereby the response of production networks can be adjusted to a standard response by making single adjustments in the elements one at a time. The only requirement, apart from the linearity of the networks, is that their elements be within reasonable range of the correct values at the outset. In the example described, this range included deviations from 10 to 20 per cent. The technique reduces simply to the adjustment of the elements, one at a time, until an indicating instrument reads zero.
Structure and function of a new class of human prolactin antagonists

Abstract Δ41–52 hPRL (human prolactin with residues 41–52 removed) is a lead compound for a new class of hPRL antagonists. The deleted sequence contains residues that functionally couple sites 1 and 2, the two hormone surfaces that each bind receptors. Δ41–52 hPRL retains 0.03% agonist activity in FDC-1 cell bioassays, a 3054-fold reduction in activity, and displays approximately 100-fold less agonist activity than G129R hPRL, an antagonist that reduces the binding of hPRL receptor at site 2 during the formation of the heterotrimeric hormone/receptor complex. Replacement of various numbers and types of residues into the gap created by the deletion of residues 41 through 52 created hPRLs with varying agonist activities, suggested that manipulation of the sequence connecting the C-terminal of helix 1 with the disulfide bond (cysteines 58 with 174) linking helices 1 and 4 modulates articulation of these helices and influences agonist activity. We have compared the antagonist activities of G129R and Δ41–52 hPRLs to induce apoptosis in Jurkat cells, a human lymphoid cell line displaying an autocrine/paracrine hPRL/receptor system. Δ41–52 hPRL induces apoptosis in a time and dose-dependent fashion. Under these same conditions G129R hPRL fails to induce apoptosis. We conclude Δ41–52 hPRL is a lead compound of a new class of hPRL antagonists capable at low concentrations of inducing apoptosis in human cells expressing an autocrine/paracrine hPRL/receptor system.
Inherited retinal degeneration: basic FGF induces phagocytic competence in cultured RPE cells from RCS rats

Abstract In RCS rats, the retinal pigment epithelium (RPE) is defective in phagocytosis of photoreceptor membranes. We have previously shown reduced expression of basic fibroblast growth factor (bFGF) in the RPE of 7–10-day-old RCS rats. This study using primary RPE cultures from rats of this age demonstrates that the phagocytic defect in the mutant RPE can be overcome by treatment with bFGF, by a mechanism involving gene transcription and that normal RPE phagocytosis, also requiring transcription, is blocked by a bFGF neutralizing antibody. The combined data point to a role for bFGF in the normal mechanism of RPE phagocytosis and the RCS defect.
The effect of liquidity constraints on futures hedging

Abstract: This paper assumes that, due to liquidity constraints, a hedge program will be terminated if the cumulative loss from futures position exceeds a certain threshold. It is shown that the constraint leads to a smaller futures position. If the hedger has a quadratic utility function, then the optimal futures position is constant regardless of the parameter values and increases as the spot position or the conventional hedge ratio increases. When the capital allocation is small, the hedger tends to ignore this restriction and chooses a larger position. Consequently, the optimal position may decrease as the capital allocation increases. For a moderate capital allocation, the optimal position increases with an increasing capital allocation. Similar properties are established for exponential utility functions. * Professor of Economics, University of Texas – San Antonio. Contact address: Department of Economics, University of Texas – San Antonio, 6900 North Loop 1604 West, San Antonio, Texas 78249-0633. E-mail: dlien@utsa.edu. The author thanks James Groff and Karan Bhanot for their assistance. An anonymous referee provides several helpful comments and suggestions.
Imazaquin and chlorsulfuron resistance and cross resistance in mutants of Chlamydomonas reinhardtii

Chlorsulfuron and/or imazaquin resistant mutants of Chlamydomonas reinhardtii strain CW15 have been obtained and shown to have actolactate synthase (ALS) with altered sensitivity to one or both of these herbicides. Herbicide resistance in the three mutants described is allelic, and resistance appears to result from a dominant or semidominant mutation in a single, nuclear gene. Imazaquin and chlorsulfuron resistant ALS from imazaquin and chlorsulfuron resistant mutants, together with single-gene Mendelian inheritance of these phenotypes, suggests that ALS is the sole site of action of the two herbicides in Chlamydomonas. A high degree of cross resistance between the two herbicides was found in only one mutant. This mutant (IMR-13) was selected for resistance to imazaquin and has a high level of in vitro resistance to both imazaquin (270-fold increased I50) and chlorsulfuron (900-fold increased I50). In another mutant selected for resistance to imazaquin (IMR-2), hyper-sensitivity to chlorsulfuron was found. A mutant selected for resistance to chlorsulfuron (CSR-5), had a substantial degree of resistance of chlorsulfuron (80-fold increased I50), but not to imazaquin (7-fold increased I50).
Retropharyngeal dissection during nasotracheal intubation: a rare complication and its management

Nasotracheal intubation carries potential risks, including nasal bleeding and other structural damage. We report a retropharyngeal dissection (or a false passage in the nasopharyngeal mucosa) during attempted nasotracheal intubation of a 54-year-old woman undergoing lower jaw reconstruction.
Effects of dietary retinyl palmitate and selenium on tumoricidal capacity of macrophages in mice undergoing tumor promotion

Abstract Dietary retinyl palmitate was administered for 22–30 weeks in CD-1 mice which had been initiated with 0.15 μmol of 7,12-dimethylbenz[ a ]-anthracene (DMBA) and promoted with 8 nmol of 12- O -tetradecanoylphorbol-13-acetate (TPA) twice weekly thereafter. This treatment resulted in a dose response in both the tumoricidal capacity of a selected number of isolated peritoneal macrophages (PM) and in skin tumor prevention. At 350 I.U./g of diet, retinyl palmitate (RP) also resulted in a 3-fold increase in the number of DM. RP significantly increased the total capacity of macrophage host defenses by increasing the number and individual capacity for cytotoxicity. Selenium (Se), at 2 parts/million in the drinking water, did not enhance PM tumoricidal capacity, although it did result in 60% reduction of mouse tumor burden.
EFFECT OF THE ESTROUS CYCLE ON THE ACTION OF TESTOSTERONE PROPIONATE ON THE ORGAN AND BODY WEIGHTS OF FEMALE RATS1

IN A PREVIOUS COMMUNICATION (1) from this laboratory, it was reported that the ultimate effect of testosterone propionate on the primary and secondary sex organs of the female rat depended upon the presence or absence of recent corpora lutea at the time of the first injection. Thus, it was found possible to produce two entirely different sets of responses in the animals, depending on whether the male hormone was first administered to a) adults at estrus or b) to immature animals or to adults at diestrus. As only the primary and secondary sex organs were considered in the report mentioned above, a repetition of the experiment appeared to be indicated for the following reasons, a). To confirm the uniformity with which the changes could be reproduced, and b), to extend the investigation to inlude certain other organs, namely, the adrenal, kidney, liver and thyroid.
Role of transcription factors Brn-3.1 and Brn-3.2 in auditory and visual system development.

THE neurally expressed genes Brn-3.1 and Brn-3.2 (refs 1–6) are mammalian orthologues of the Caenorhabditis elegans unc-86 gene7 that constitute, with Brn-3.0 (refs 1–3,8,9), the class IV POU-domain transcription factors10. Brn-3.1 and Brn-3.2 provide a means of exploring the potentially distinct biological functions of expanded gene families in neural development. The highly related members of the Brn-3 family have similar DNA-binding preferences1,2 and overlapping expression patterns in the sensory nervous system, midbrain and hindbrain1–6,8,9, suggesting functional redundancy. Here we report that Brn-3.1 and Brn-3.2 critically modulate the terminal differentiation of distinct sensorineural cells in which they exhibit selective spatial and temporal expression patterns. Deletion of the Brn-3.2 gene causes the loss of most retinal ganglion cells, defining distinct ganglion cell populations. Mutation of Brn-3.1 results in complete deafness, owing to a failure of hair cells to appear in the inner ear, with subsequent loss of cochlear and vestibular ganglia.
Reticulo- and trigemino-hypoglossal connections: a quantitative comparison of ultrastructural substrates

Axon terminals were identified and characterized by electron microscopy after injections of horseradish peroxidase (HRP) into the spinal V nucleus (SPVN) or the medullary reticular formation adjacent to the XIIth nucleus. The synaptic organization and topology of these two different populations of hypoglossal afferents (T-XII and R-XII respectively) were determined by quantitative comparisons. Significant differences were obtained in the ratios of morphological types of terminals, sizes of axonal endings and their location on postsynaptic structures. Axon terminals containing spherical vesicles (S-terminals) and those with flattened/pleomorphic vesicles (F-terminals) were anterogradely labeled with HRP from both injection sites. However, the S/F ratio for R-XII terminals was 1.2:1 compared to 2.6:1 for T-XII afferents. Asymmetrical membrane densities (Gray Type I) were the predominant form of junctional specialization for S-terminal synapses. Asymmetrical densities with subjunctional dense bodies/bars (S-Taxi) were associated with a higher proportion of T-XII synapses than R-XII synapses. Almost all of the F-terminals from both sources had symmetrical densities (Gray Type II). The average diameter of R-XII terminals was greater than that of T-XII terminals. R-XII-F terminals were the largest terminals. The majority of axon terminals from both sources formed axodendritic synapses. However, R-XII terminals had a higher incidence (10% vs. 3%) of axosomatic contacts. The proportion of R-XII-F-terminals decreased from the central toward the distal dendrites, whereas the opposite was found for T-XII-F and T-XII-S-terminals. In contrast to these findings, R-XII-S-terminals were more uniformly distributed on dendrites of all sizes.(ABSTRACT TRUNCATED AT 250 WORDS)
A computer model of the periodontal ligament space in man

An engineering model of the periodontal ligament fibres was used to calculate length changes in the fibres with: direct occlusal forces on the tooth, occlusal loads on other teeth in the arch and splinting. The fibre elongations appear to influence tooth eruption, the clinical behaviour of splinted and non-splinted teeth, and the establishment of vertical dimension of occlusion and occlusal plane height. The model also provides insight into the controversy surrounding the intermediate plexus of the ligament.
Analysis of a current pulse generator regulated by a square-loop ferrite core

Existing current-pulse-generator circuits are briefly discussed. For driving inductive loads, the circuit giving the least overshoot for a given rise-time has been found to be one in which the current is regulated by a square-loop core. Its operation is described, and the degree of overshoot calculated for the case of a load consisting of series resistance and inductance. A worked example is given.
Surface finishing of alkali halides

The production of smooth scratch-free surfaces on the alkali halides KCl and NaCl by means of solvent action is described. It is shown by etching studies that very few dislocations are introduced by this process. Surfaces of the type described are of particular value in the study of the optical absorption of very low loss materials.
Diffusion and Performance of CAD/CAM in the U.S. Textile and Apparel Industry

This study examines the determinants of CAD/CAM adoption and diffusion in American textile and apparel industries. Innovation diffusion theory provided a conceptual framework and empirical base applicable to the study of technology adoption and implementation. A variety of sources were used to develop the survey which was mailed to a national random sample of 500 textile and apparel manufacturers. The responses of 103 manufacturers from 30 different states were analyzed. Factor analysis was used to identify the dimensions of reasons for CAD/CAM adoption. Hypotheses were tested with logistic regression analysis procedures. The diffusion of CAD/CAM practices was found to be driven primarily by the market and affected by the business-unit size. In addition, labor considerations affected recent CAD/CAM adoption.© 2002 ASME
Inactivation of the 20S proteasome in Mycobacterium smegmatis

The 20S proteasome is an essential component of the cytosolic protein turnover apparatus of eukaryotic cells. In higher eukaryotes, the 20S proteasome is responsible for most cytosolic protein turnover and also generates peptides for subsequent presentation by the MHC class I pathway. Structurally, the eukaryotic 20S proteasome is extremely complex, being composed of 14 different subunits. Proteasomes with simplified subunit composition have been identified in certain eubacteria and archaebacteria but, in each case, the proteasome-containing organism is recalcitrant to further molecular genetic analyses. As a result, no in vivo characterization of a simplified eubacterial or archaebacterial proteasome has been reported. We have shown that the genetically tractable eubacterium Mycobacterium smegmatis contains a 20S proteasome, allowing the first in vivo characterization of a simplified 20S proteasome. We use a positive/negative selection scheme to inactivate the genes encoding 20S proteasome subunits and demonstrate that, in contrast to eukaryotic cells, M. smegmatis cells lacking intact proteasome genes are viable and phenotypically indistinguishable from congenic strains containing proteasomes. Implications for the evolution of the protein turnover apparatus are discussed.
Sequential consistency and the lazy caching algorithm

I introduce and discuss sequential consistency, a relaxed memory model, and define what it means for a protocol to implement sequential consistency. Then, I introduce the lazy caching protocol of Afek, Brown and Merrit [ABM93] and formalize it as a labeled transition system.
Contemporary Ethics from an Ambiguous Past

Kaveny recommends models drawn from the Gospel of John and the practices of the early church for modern Christians in their response to older women and their health needs. She draws upon a historical reconstruction of the early Christian Order of Widows to propose a normative standard of care for elderly women, one that attends seriously to their bodily needs but also to their needs for inclusion and engagement in the social and vocational world both as givers and recipients of care. This is also to serve as an overarching model for a bioethics that prizes the embodied existence of all women and rejects judgments of appropriate treatment based on their social utility. The following response raises questions about the exegetical and historical foundations of Kaveny's analysis. However, these caveats may not detract substantially from the normative usefulness of her work.
Testicular microlithiasis as a predictor of intratubular germ cell neoplasia

Sonographically detected testicular microlithiasis is an uncommon condition, which in recent years has been demonstrated with increased prevalence in patients with testicular tumors. We report a case of a 31-year-old man with left testicular carcinoma and right intratubular germ cell neoplasia diagnosed by biopsy of the right testis at the time of left radical orchiectomy. In this case, preoperative ultrasound revealed right testicular microlithiasis, signaling the presence of intratubular germ cell neoplasia. We propose ultrasound as a noninvasive tool for selecting patients for testicular biopsy.
The Influence of Endocrine Disruptors on Male Pubertal Timing

Wildlife observations and toxicological studies in animals have revealed that endocrine disruptors have adverse effects on reproductive health, including altering the timing of pubertal development in both males and females. In contrast to the early puberty observed with EDC exposure in females, most antiandrogenic and estrogenic compounds cause a delay in male pubertal onset accompanied by dysfunction of testicular steroidogenic pathways and perturbation in secondary sexual maturation. Animal studies have identified critical windows of vulnerability for susceptibility that vary among compounds. For several estrogenic compounds such as DES and DDE, the juvenile and peripubertal windows are key exposure periods for the outcome of preputial separation, a hallmark of pubertal onset in male rodents. Gestational and neonatal exposures have been shown to have no impact on pubertal timing. Conversely, gestational exposures to PCBs, dioxins, and flutamide (an antiandrogen) delay pubertal onset. A small but growing number of epidemiologic studies have shown that EDCs can also alter pubertal timing and progression in humans. Recent studies demonstrate an association of lead, dioxins, endosulfan, and PCBs on delaying onset of puberty and age of attaining pubertal milestones and a weaker association of serum organochlorines with earlier puberty. Cumulatively, these studies have identified key factors that affect vulnerability and toxicity. Dose, duration, and timing of exposure, genetic susceptibility, and the endogenous endocrine milieu may all modulate the effects of exposures to EDCs. Human studies are further complicated by the long interval between exposure and outcome and the likelihood of mixed exposures which may have opposing, additive, or synergistic actions on the reproductive system. In conclusion, animal and human data confirm perturbations in pubertal onset and attainment of late pubertal stages with early-life exposures to EDCs.
A spice-like reliability model for deep-submicron CMOS technology

Continuing down scaling in CMOS technology has resulted in an increasing and urgent need for a Spice-like reliability model that is capable of predicting the long-term degradation of MOS devices and ICs. In this paper, we develop such a model based on the industry standard BSIM3 model and empirical degradation expressions for the threshold voltage and mobility of MOSFETs. The model is implemented in Cadence Spectre via Verilog-A, and good agreements between the measured and simulated results have been obtained for devices fabricated from the 0.18-μm CMOS technology.
Rules and Resemblance: Their Changing Balance in the Category Learning of Humans (Homo sapiens) and Monkeys (Macaca mulatta)

In an early dissociation between intentional and incidental category learning, Kemler Nelson (1984) gave participants a categorization task that could be performed by responding either to a single-dimensional rule or to overall family resemblance. Humans learning intentionally deliberately adopted rule-based strategies; humans learning incidentally adopted family-resemblance strategies. The present authors replicated Kemler Nelson’s human experiment and found a similar dissociation. They also extended her paradigm so as to evaluate the balance between rules and family-resemblance in determining the category decisions of rhesus monkeys. Monkeys heavily favored the family-resemblance strategy. Formal models showed that even after many sessions and thousands of trials, they spread attention across all stimulus dimensions rather than focus on a single, criterial dimension that could also produce perfect categorization.
Distribution of liquids introduced into the uterus with a simple "nonocclusive" cannula.

Abstract In order to investigate possible reasons for inconsistent tubal occlusion when a suspension of quinacrine is introduced into the uterus, the following radiographic investigations were carried out: 4ml of renografin 60 which has the same approximate viscosity as a suspension of quinacrine, were introduced into the uteri of sixteen normal parous women and the distribution followed by fluoroscopy and x-ray. The same type of instrument which had previously been used to introduce quinacrine, namely, a 3.4mm cannula with no cervical occlusive tip, was employed. The contrast material failed to enter one or both oviducts in four out of sixteen cases (25%), even though subsequent hystero-salpingograms revealed patent oviducts. However, if patients wearing IUDs were excluded, renografin 60 failed to enter the patent oviducts in only one out of eleven cases (9%). A much more viscous contrast material, Salpix, failed to enter patent oviducts in one out of thirteen women (8%) including three who were wearing IUDs. There was less peritoneal spillage with the more viscous contrast material. These studies suggest that failure of a suspension of quinacrine to enter the oviduct is at least one reason for failure of this technique to occlude the fallopian tube. They also suggest that a more viscous preparation may lead to more consistent filling of the oviducts when a cannula without an occlusive tip is used to introduce the preparation into the uterus.
Afferent Renal Nerves and Hypertension

Adenosine-sensitive nerve endings have been found in the renal pelvis which when stimulated increase sympathetic activity producing hypertension. When urinary adenosine concentration is lowered by intrarenal infusion of adenosine deaminase in one-kidney one-clip rats, peripheral sympathetic nervous system activity and arterial pressure decrease if the renal nerves are intact. These data suggest that a stimulus for afferent renal nerve activity in one-kidney, one-clip hypertension is intrarenal adenosine. This intrarenal adenosine hypertensive reflex was examined further observing the responses to renal pelvic xylocaine infusion, selective renal deafferentation, adrenal demedullation and spinal cord transection (T6). The intrarenal adenosine hypertensive reflex was interrupted by renal pelvic xylocaine infusion, renal deafferentation and adrenal demedullation in normotensive and one-kidney, one-clip hypertensive animals. The intrarenal adenosine hypertensive reflex persisted after spinal cord transection (...
Nonsteroidal Anti-inflammatory Drug Induced Thrombotic Thrombocytopenic Purpura

A 21-year-old male presented to the emergency department after a 5-day history of recurrent vomiting and decreased urine output. ­History revealed ingestion of ibuprofen. During the diagnostic workup, the following was identified: white blood cell count 13.4 (×10(3)/mcL), hemoglobin 11.9 (×10(6)/mcL) with an MCV of 73 fL, hematocrit 34% and platelets were 31,000/mcL, sodium of 130 mmol/L, potassium of 5.1 mmol/L, chloride of 83 mmol/L, bicarbonate of 21 mmol/L, blood urea nitrogen of 184 mg/dL and creatinine of 19.1 mg/dL. He was later diagnosed with thrombotic thrombocytopenic purpura (TTP) based on the fact that he presented with most components of the TTP pentad (except for fever), which included altered mental status, acute kidney injury, thrombocytopenia, and evidence of red cell fragmentation and his ADAMTS13 level was found to be less than 10% prior to therapy. The patient then received plasma exchange, oral corticosteroids, and hemodialysis, which led to a full recovery of platelet count and renal function.
Effect of nitration on protein tyrosine phosphatase and protein phosphatase activity in neuronal cell membranes of newborn piglets.

Protein tyrosine phosphatase predominantly determines the status of protein tyrosine kinase-dependent phosphorylation of specific proteins and controls the survival and death of neurons. Previous studies have shown that protein tyrosine phosphatase activity is decreased during hypoxia in cortical membranes of the newborn piglet. We have also shown that nitric oxide (NO) free radicals are generated during hypoxia, and may result in modification of protein tyrosine phosphatase via peroxynitrite-mediated modification. The present study tests the hypothesis that the hypoxia-induced decrease in protein tyrosine phosphatase activity is NO-mediated. To test this hypothesis, in vitro experiments were conducted by measuring protein tyrosine phosphatase activity in the presence of an NO donor, sodium nitroprusside (SNP), or peroxynitrite. Since 3-nitrotyrosine is produced as a consequence of peroxynitrite reactions, we have also examined the effect of 3-nitrotyrosine on protein phophatase activity. Cerebral cortical P2 membranes were prepared from seven normoxic newborn piglets and each sample was divided into three aliquots: a control group, a SNP group (exposed to 200 μM SNP), and a peroxynitrite group (exposed to 100 μM peroxynitrite). Protein tyrosine phosphatase activity was determined spectrophotometrically in the presence or absence of 2 μM bpV(phen), a highly selective inhibitor of protein tyrosine phosphatase. The protein tyrosine phosphatase activity was 198 ± 25 nmol/mg protein/h in the normoxic group, 177 ± 30 nmol/mg protein/h in the SNP group (p = NS versus normoxic) and 77 ± 20 nmol/mg protein/h in the peroxynitrite group (p < 0.001 versus normoxic). The results show that peroxynitrite but not SNP exposure results in decreased protein tyrosine phosphatase activity in vitro. Furthermore 3-nitrotyrosine (100 μm), a product of peroxynitrite, decreased the enzyme activity from 926 ± 102 to 200 ± 77 (p < 0.001). We conclude that protein tyrosine phosphatase regulation is mediated by peroxynitrite. We propose that hypoxia-induced NO production leading to peroxynitrite formation is a potential mechanism of protein tyrosine phosphatase inactivation in vivo. The NO-induced decrease in protein tyrosine phosphatase and protein phosphatase activity, leading to Bcl-2 protein phosphorylation and loss of its antiapoptotic activity may be a NO-mediated mechanism of programmed cell death in the hypoxic brain.
Ultrasonographic localization of non-palpable breast masses.

Abstract Preoperative ultrasound was used as an alternative to x-ray mammography to localize 92 breast lesions encountered in 82 patients. Recommendation for biopsy was made based upon the ultrasonographic finding of a nonpalpable mass or an area of architectural distortion, or in the presence of equivocal physical findings if sonomammography demonstrated a solid or anechoic mass. Sonomammography was performed in the operating room, just prior to anticipated biopsy, using a hand-held, high resolution scanner. When the suspicious area was imaged, and its precise location noted, the breast was then prepped and draped in the usual manner, and biopsy performed. If the suspicious area could not be easily localized after the incision was made and the breast explored, the transducer was “gowned” and used directly in the wound to help find the lesion. This technique has proven effective and accurate. In selected patients, ultrasound may be used instead of, and as well as, x-ray needle localization for the precise excision of non-palpable breast masses and areas of parenchymal distortion. Microcalcifications must still be addressed by x-ray mammography and needle localization with specimen radiography.
Computed Tomographic Diagnosis of Ureteral Obstruction Secondary to Aneurysmal Disease

Three cases of ureteral obstruction associated with aortoiliac aneurysms were studied with computed tomography. CT was able to document the presence of aneurysm and display the perianeurysmal, fibrotic, contrast-enhancing mass accounting for ureteral obstruction. The value of computed tomography in the diagnosis and evaluation of these cases is described.
Observations on scopoletin and scopolin metabolism

Abstract The specific activities of scopoletin and scopolin synthesized by tobacco callus from uniformly labeled phenylalanine reached a maximum at 18 hr and then decreased. The formation of scopolin was not influenced by the presence or absence of 2 mg/l. IAA in the incubation medium in 15-hr experiments. In the range 21 to 165 mg/l. phenylalanine, the specific activities of the scopoletin and scopolin produced as well as their concentrations were constant; at higher phenylalanine concentrations, their specific activities decreased. The specific activity of scopoletin was higher than that of scopolin in all experiments. On incubation of tobacco callus with labeled scopolin, little of the activity was incorporated into true lignin; most of the activity was associated with the protein and cell-wall fractions. When pea-stem segments were incubated with scopoletin, they formed an insoluble material which, when oxidized with nitrobenzene, produced little extra vanillin.
Calibration methodology and performance characterization of a polarimetric hyperspectral imager

Polarimetric hyperspectral imaging (P-HSI) has the potential to improve target detection, material identification, and background characterization over conventional hyperspectral imaging and polarimetric imaging. To fully exploit the spectro-polarimetric signatures captured by such an instrument, a careful calibration process is required to remove the spectrally- and polarimetrically-dependent system response (gain). Calibration of instruments operating in the long-wave infrared (LWIR, 8μm to 12 μm) is further complicated by the polarized spectral radiation generated within the instrument (offset). This paper presents a calibration methodology developed for a LWIR Telops Hyper-Cam modified for polarimetry by replacing the entrance window with a rotatable holographic wire-grid polarizer (4000 line/mm, ZnSe substrate, 350:1 extinction ratio). A standard Fourier-transform spectrometer (FTS) spectro-radiometric calibration is modified to include a Mueller-matrix approach to account for polarized transmission through and polarized selfemission from each optical interface. It is demonstrated that under the ideal polarizer assumption, two distinct blackbody measurements at polarizer angles of 0°, 45°, 90°, and 135° are sufficient to calibrate the system for apparent degree-of-linear-polarization (DoLP) measurements. Noise-equivalent s1, s2, and DoLP are quantified using a wide-area blackbody. A polarization-state generator is used to determine the Mueller deviation matrix. Finally, a realistic scene involving buildings, cars, sky radiance, and natural vegetation is presented.
Electron-impact promoted fragmentation of alkyl-N-(1-phenylethyl)-carbamates of primary, secondary and tertiary alcohols

The mass spectra of twenty alkyl carbamates derived from primary, secondary, and tertiary alcohols are investigated, using deuterium labeling and high-resolution mass spectrometry. Several of the primary and secondary alcohol derivatives are found to yield an ion formally equivalent to the product ion of a McLafferty rearrangement. Deuterium labeling, however, revealed a lack, in these carbamate derivatives, of the usual site specificity associated with the McLafferty rearrangement. A double hydrogen rearrangement process was observed in the mass spectra of several carbamates derived from tertiary alcohols.
Response of hematological and biochemical parameters to heavy metal exposure: Implications in environmental monitoring

Abstract The use of selected hematological and biochemical parameters as indicators of metal exposure in aquatic organisms was evaluated. The hematological and biochemical parameters examined include glucose, hematocrit and aminotransferase levels in golden shiners exposed to cadmium. Cadmium exposure produced significant alterations in the levels of glucose, aspartate aminotransferase and alanine aminotransferase; however, hematocrit was not altered by exposure to cadmium. In addition, the comparative activity of Na/K adenosine triphosphatase (ATPase) was evaluated in the fathead minnow, golden shiner and bluegill sunfish. Basal Na/K ATPase activity was lowest in golden shiner (1·01 μmol Pi/mg protein/h) and highest in bluegill sunfish (1·45 μmol Pi/mg protein/h). While a stimulation of Na/K ATPase activity was observed at an exposure concentration of 1 μg Cd/liter in the fathead minnow and bluegill sunfish, inhibition of enzymatic activity was observed at higher exposure concentrations (10 and 100 μg Cd/liter). Gill Na/K ATPase activity in golden shiner was not significantly influenced by cadmium exposure. The observed insensitivity of ATPase in shiner may, in part, be related to higher background and accumulated concentrations of cadmium in gill tissue.
Psychological distress of female cancer caregivers: effects of type of cancer and caregivers' spirituality.

Introduction This study examined the effects of the survivor’s cancer type (gender-specific vs nongender-specific) and the female caregiver’s spirituality and caregiving stress on the caregiver’s psychological distress. Cancer caregivers, who were nominated by cancer survivors, participated in a nationwide quality-of-life survey with 252 caregivers providing complete data for the variables.
Myelination: Coordinated regulation of many molecular elements

The formation of the myelin sheath requires the coordinated regulation of a number of gene products, both glial and axonal. These include the myelin structural genes, enzymes involved in lipid biosynthetic pathways, transcriptional regulators, trophic and recognition factors. Alterations in gene dosage or gene expression timing can have profoundly deleterious effects on either the establishment or maintenance of the myelin sheath. In this review, the major structural genes are described, as are the consequences of changes in gene dosage which occur as a result of either natural mutations or experimentally mediated events. While it is clear that our knowledge has expanded greatly with regard to these events, there continue to be large gaps, especially within the genetics of gene regulation and the mechanisms of glial axon interactions. MRDD Research Reviews 1998; 4:179–186 © 1998 Wiley-Liss, Inc.
Cellular and molecular biology of neural crest cell lineage determination

The past few years have seen an explosion of information about genes that control the development of the neural crest, a structure unique to vertebrate embryogenesis. Many of these genes are mutated in human diseases that affect crest-derived lineages. At the same time, decades of work on the neural crest at the cellular level are generating new insights into the segregation of different lineages and the role played by environmental signals in the lineage-commitment process. The challenge now is to integrate the cellular and molecular genetic perspectives on neural crest development. This review attempts such a synthesis.