cssi/SciSciGPT-SciSciNet huggingface dataset:
Economic comparison of reproductive programs for dairy herds using estrus detection, timed artificial insemination, or a combination

The objective of this study was to compare the economic outcome of reproductive programs using estrus detection (ED), timed artificial insemination (TAI), or a combination of both (TAI-ED) using a stochastic dynamic Monte-Carlo simulation model. Programs evaluated were (1) ED only; (2) TAI: Presynch-Ovsynch for first AI, and Ovsynch for resynchronization of open cows at 32 d after AI; (3) TAI-ED: Presynch-Ovsynch for first AI, but cows underwent ED and AI after first AI, and cows diagnosed open 32 d after AI were resynchronized using Ovsynch. Evaluated were the effect of ED rate (40 vs. 60%; ED40 or ED60), accuracy of estrus detection (85 vs. 95%), compliance with the timed AI protocol (85 vs. 95%), and milk price ($0.33 vs. 0.44/kg). Conception rate to first service was set at 33.9% and then decreased by 2.6% for every subsequent service. Abortion was set at 11.3%. Cows were not AI after 366 d in milk, and open cows were culled after 450 d in milk. Culled cows were immediately replaced. Herd size was maintained at 1,000 cows, and the model accounted for all incomes and costs. Simulation was performed until steady state was reached (3,000 d), and then average daily values for the subsequent 2,000 d were used to calculate profit/cow per year. Net daily value was calculated by subtracting the costs (replacement, feeding, breeding, and other costs) from the daily income (milk sales, cow sales, and calf sales). The ED40 models resulted in greater profits than the TAI-85 model but lower profits than the TAI-95 model. Both ED60 models resulted in greater profits than the TAI-95 model. Combining TAI and ED increased profits within each level of accuracy or compliance. Adding TAI to ED would increase overall profit/cow per year by $46.8 to $74.7 with 40% ED, and by $8.9 to $30.5 with 60% ED. Adding ED to TAI would increase profit/cow per year by $64.2 to $99.4 with 85% compliance and by $31.8 to $59.7 with 95% compliance. Although combining TAI and ED increased profits within each level of accuracy or compliance, when evaluated separately, ED60 with 95% accuracy or TAI with 95% compliance were as profitable as or more profitable than TAI-ED with low ED, accuracy, or compliance. Therefore, producers can improve their profits by combining TAI and ED as reproductive management; however, if a herd can achieve high ED with high accuracy or have high compliance with injections, using only ED or TAI might be more profitable than trying to do both.
Longitudinal epigenetic variation of DNA methyltransferase genes is associated with vulnerability to post-traumatic stress disorder.

Background. Epigenetic differences exist between trauma-exposed individuals with and without post-traumatic stress disorder (PTSD). It is unclear whether these epigenetic differences pre-exist, or arise following, trauma and PTSD onset. Method. In pre- and post-trauma samples from a subset of Detroit Neighborhood Health Study participants, DNA methylation (DNAm) was measured at DNA methyltransferase 1 (DNMT1), DNMT3A, DNMT3B and DNMT3L. Pre-trauma DNAm differences and changes in DNAm from pre- to post-trauma were assessed between and within PTSD cases (n = 30) and age-, gender- and trauma exposure-matched controls (n = 30). Pre-trauma DNAm was tested for association with post-trauma symptom severity (PTSS) change. Potential functional consequences of DNAm differences were explored via bioinformatic search for putative transcription factor binding sites (TFBS). Results. DNMT1 DNAm increased following trauma in PTSD cases (p = 0.001), but not controls (p = 0.067). DNMT3A and DNMT3B DNAm increased following trauma in both cases (DNMT3A: p = 0.009; DNMT3B: p < 0.001) and controls (DNMT3A: p = 0.002; DNMT3B: p < 0.001). In cases only, pre-trauma DNAm was lower at a DNMT3B CpG site that overlaps with a TFBS involved in epigenetic regulation (p = 0.001); lower pre-trauma DNMT3B DNAm at this site was predictive of worsening of PTSS post-trauma (p = 0.034). Some effects were attenuated following correction for multiple hypothesis testing. Conclusions. DNAm among trauma-exposed individuals shows both longitudinal changes and pre-existing epigenetic states that differentiate individuals who are resilient versus susceptible to PTSD. These distinctive DNAm differences within DNMT loci may contribute to genome-wide epigenetic profiles of PTSD.
Effects of psychoactive and non-psychoactive cannabinoids on neuroendocrine and testicular responsiveness in mice

Repeated oral administration of the non-psychoactive cannabinol (CBN; 5 or 50 mg/kg) significantly reduced the concentration of norepinephrine (NE) in median eminence and greatly reduced NE levels 1 and 2 hrs after administration of alpha-methylparatyrosine (alpha-MPT). The levels of dopamine (DA) in median eminence were significantly different, as indicated by the differences in slopes obtained in CBN- treated and control mice before and after alpha-MPT. Plasma levels of luteinizing hormone (LH) were significantly reduced in CBN-exposed mice before alpha-MPT, elevated at 1 hr post-injection, but were also reduced 2 hrs post-injection at 50 mg/kg CBN. Follicle-stimulating hormone (FSH) levels were increased at 1 hr post-alpha-MPT in mice receiving 50 mg/kg CBN. Oral administration of CBN at 50 mg/kg for 4 days enhanced testicular testosterone (T) production in response to intratesticular in vivo injection of 2.5 or 25 mIU human chorionic gonadotropin (hCG). A single oral dose of the psychoactive delta 9-tetrahydrocannabinol (THC) enhanced the production of T 15 min after intratesticular LH (10 ng) injection. However, at 45 or 60 min post-THC treatment, the response to LH was significantly attenuated. These studies demonstrate that both psychoactive and non-psychoactive components of marihuana alter testicular responsiveness to gonadotropins in vivo. These effects may be biphasic, involving stimulation and inhibition of responsiveness, and appear to be correlated with alterations in plasma LH levels. Alterations in plasma gonadotropins may be mediated by cannabinoid effects on catecholamine concentrations in median eminence and THC-induced alterations in testicular responsiveness to gonadotropin probably also involve direct effects of THC at the gonadal level.
The excited state as a source and detector for high frequency phonons

Abstract We review the use of the excited states of impurity ions in solids as a source and detector of high frequency phonons and describe a new phonon detector which uses phonon-induced coherence loss (PICOLO). For sources, we consider excited state relaxation, including stimulated emission of phonons. For detectors, we discuss hot luminescence, vibronic sideband phonon spectroscopy and PICOLO.
Adhesion promotion between metadent and a high palladium alloy with a pyrolytically fused porcelain opaque layer.

PURPOSE Several authors have reported a preference for the use of high palladium alloys in the construction of implant-fixed partial denture (IFPD) substructures. Heat-polymerized polymethyl methacrylate resins (PMMR) are used to secure denture teeth to IFPD substructures. Metadent (Sun Medical Co, Kyoto, Japan), a heat-polymerized PMMR containing 5% 4-methacryloxyethyl trimellitate anhydride (4-META), could possibly improve the overall design of the prosthesis because this resin adheres to resin and ceramic denture teeth and noble metals. However, adhesive bonding between Metadent and elemental palladium has been shown to be poor. The purpose of this study was to evaluate the potential for adhesive bonding between Metadent, titanate primers, and a ceramic layer pyrolytically fused to a high palladium alloy. MATERIALS AND METHODS Five groups of 10 specimens were prepared. A layer of opaque porcelain was baked on all of the specimens under vacuum at 1760 degrees F. The specimens were grouped as follows: (1) Metadent resin processed on ceramic with no primer, (2) Metadent resin with 10% ethyl acetoacetate titanate (DC) processed on ceramic with no primer, (3) Metadent resin with 10% DC processed to ceramic with a 2% tetraisopropyl (TPT) surface primer, (4) 4-Metadent resin with 10% DC processed to ceramic with a 2% isopropyl dimethacryloyl isostearoyl titanate (KR-7) surface primer, and (5) Metadent resin with 10% DC processed to ceramic with a titanium dioxide layer on the opaque and a KR-7 surface primer. The primers were in a methyl methacrylate (MMA) solution. All of the specimens were heat-polymerized under pressure at 212 degrees F for 1 hour. One-half (25) of the specimens (5 from each group) were hydro-thermocycled at 4 degrees C to 55 degrees C, 0.5 minute dwell per bath for 3,000 cycles. All specimens were tested in shear on an MTS Universal machine at cross head speeds of 0.5/mm/min. RESULTS The results showed adhesion between the resin-ceramic layer in virtually all groups regardless of thermocycling effects. The control (heat cure without 10% DC and no primer) and the 10% DC with KR-7 and TPT primer groups had an average MPa of 7.5, 7.7, and 7.0, respectively. The failure mode of the specimens was adhesive, with the site of failure being the porcelain-metal interface. CONCLUSION It was concluded that adhesion between palladium alloy and Metadent was possible when a ceramic layer was used as an intermediary interface. The limitation seemed to be the adhesion of the ceramic to the metal.
Isotopic exchange between snow and atmospheric water vapor: Estimation of the snowmelt component of groundwater recharge in the southwestern United States

[1] The contribution of snowmelt to groundwater recharge at four sites in the southwestern United States was evaluated using stable isotopes of O and H. Paired precipitation collectors were installed at the study sites; data show that (1) there is often a significant difference between the stable isotope composition of fresh snow and the bulk meltwater derived from it (this suggests that using the isotope composition of high-elevation springs as a proxy for precipitation may not be sound if snow is a recharge source) and (2) collector design can significantly influence the stable isotope composition of collected snow. Because the isotope composition of snow from a given location becomes heavier (i.e., more rain-like) with increased exposure, using bulk snowmelt compositions to calculate input to groundwater recharge results in significantly increased estimates of snowmelt contributions to recharge (compared to estimates derived from fresh snow signatures). Snowmelt provides at least 40–70% of groundwater recharge at the study sites, although only 25–50% of average annual precipitation falls as snow. On the basis of these results and presently accepted scenarios for alterations in precipitation in the western United States over the next 50 years (significantly decreased snowpack due to increased atmospheric CO2), investigations of how climate change may affect groundwater resources are needed. We also investigated the potential for snow/atmospheric water vapor isotope exchange to influence the isotope signature of snow (which has been a subject of debate); the results of a laboratory experiment suggest that it can drive significant shifts in the isotope signature of snow, even at temperatures below 0°C.
Inducer expulsion is not a determinant of diauxic growth in Streptococcus bovis.

When Streptococcus bovis JB1 was repeatedly transferred in a medium that contained the non-metabolizable glucose analog, 2-deoxyglucose, it lost its phosphotransferase system (PTS) for glucose but was still able to take up glucose via a facilitated diffusion mechanism. The wild type (JB1) had an inducible enzyme II lactose, but the mutant (JB12DG) had a constitutive lactose PTS. JB12DG was no longer able to exclude lactose when it was provided with glucose, but it retained its ability to expel a non-metabolizable lactose analog. Because JB12DG could utilize glucose and lactose simultaneously and grow in a non-diauxic fashion, it appeared that inducer expulsion was not an important catabolite regulatory mechanism. Based on these results, inducer expulsion may be an artifact of non-metabolizable sugars.
ICESat over Arctic sea ice: Estimation of snow depth and ice thickness

[1] Starting with retrieved freeboards from four ICESat campaigns (ON05, October/November 2005; FM06, February/March 2006; ON06, October/November 2006; and MA07, March/April 2007) we estimate their ice thicknesses using constructed fields of daily snow depth and compare them with ice drafts from moored upward-looking sonars. The methodologies, considerations, and assumptions used in the conversion of freeboard to ice thickness are discussed. The thickness distributions of the Arctic multiyear and seasonal ice covers are contrasted. Broadly, the resulting fields seem seasonally and interannually consistent in terms of thickness, growth and ice production. We find mean thicknesses of 2.15/2.46 m in ON05/FM06 and an overall thinner ice cover of 1.96/2.37 m in ON06/MA07. This represents a growth of ∼0.3 m and ∼0.4 m during the ∼4-month intervals of the ON05-FM06 and ON06-MA07 campaigns, respectively. After accounting for data gaps, we compute overall Arctic Ocean ice volumes of 11,318, 14,075, 10,626, and 13,891 km3 for the ON05, FM06, ON06, and MA07 campaigns, respectively. The higher total volume in ON05 (versus ON06) can be attributed to the higher multiyear ice coverage that fall: 37% versus 31%. However, the higher estimated ice production (less export) during the second year (3265 versus 2757 km3) is likely due to the higher growth rate over the larger expanse of seasonal sea ice during the fall and winter. Inside a 25-km radius of two mooring locations in the Beaufort Sea, the estimated mean ICESat ice drafts from ON05 and FM06 are within 0.5 m of those measured at the moorings.
An empirical method for inferring species richness from samples

We introduce an empirical method of estimating the number of species in a community based on a random sample. The numbers of sampled individuals of different species are modeled as a multinomial random vector, with cell probabilities estimated by the relative abundances of species in the sample and, for hypothetical species missing from the sample, by linear extrapolation from the abundance of the rarest observed species. Inference is then based on likelihoods derived from the multinomial distribution, conditioning on a range of possible values of the true richness in the community. The method is shown to work well in simulations based on a variety of real data sets. Copyright © 2005 John Wiley & Sons, Ltd.
A robust digital watermarking technique with improved performance under JPEG compression

Digital watermarking is an important technique to protect copyrighted multimedia data. This technique works by hiding secret information into the images. Therefore, it can be used to discourage illicit copying or distribution of copyrighted materials. In this paper, we propose a robust frequency domain digital watermarking algorithm for still image based on discrete cosine transformation. Adjustable parameters are introduced during the watermark embedding process, which adaptively change the JPEG quantization factor, as well as the depth at which the watermark is embedded. The proposed watermarking technique still maintains its validity under certain image processing operations such as low pass filtering, image cropping, etc. Compared with previous method, however, it has improved performance under Joint Photographic Experts Group (JPEG) compression attack. The extracted watermark maintains its high quality in terms of normalized correlation even under a high JPEG compression ratio.
Poly[p-(phenyleneethynylene)-alt-(thienyleneethynylene)] Polymers with Oligopyridine Pendant Groups: Highly Sensitive Chemosensors for Transition Metal Ions

We report the synthesis and characterization of a series of luminescent chemosensory materials that have the conjugated polymer poly[p-(phenyleneethynylene)-alt-(thienyleneethynylene)] (PPETE) as a backbone and oligopyridine pendant sites as receptors. These polymers are soluble in common organic solvents and highly emissive. Investigations reveal that these polymers are highly sensitive to transition metal ions such as Ni2+. For the terpyridine−receptor polymer ttp−PPETE, we observed ∼5% initial emission quenching by Ni2+ concentration as low as 4 × 10-9 M. The polymers also show selectivity to different transition metal ions. The ether-linked polymer ttp−O−PPETE is also prepared which successfully demonstrates that complete conjugation is not required for emission quenching. However, the vinylene-linked ttp−PPETE was found to have a higher quenching efficiency.
Function-Specific High-Probability "Nodes" Identified in Posterior Language Cortex

Summary: Purpose: Posterior, “Wenicke's,” language areas have a high degree of between-subject variability, as shown by electrical-stimulation mapping. We investigated the possibility of an organized structure in the distribution of posterior language areas. Methods: Extraoperative subdural grid stimulation was performed on 67 left hemisphere-dominant patients before resec-tive epilepsy surgery during counting, naming, and reading. Intersubject-averaged language maps were generated in which stimulation disrupted only one language function and not the others, or combinations of language functions. Results: Language sites, although highly variable between subjects, were not organized randomly and appeared to be arranged into several focal, non-contiguous, higher probability “nodes” devoted to different aspects of language processing. Speech-arrest sites were concentrated in classic Wernicke's area. Areas where stimulation induced only reading errors were found in the posterior middle temporal gyrus and the inferior parietal lobule. These regions may correspond with an orthographic input lexicon. Areas eliciting only naming errors were found in the posterior inferior temporal gyrus extending into the mid-middle temporal gyrus and may represent a visual-representation input lexicon. Sites where stimulation elicited errors in both naming and reading were more variable in location than sites devoted to only one function, extended farther anteriorly along the temporal neocortex, and may correspond with a semantic lexicon. Conclusions: The existence of high-probability nodes in posterior language cortex supports a modality-specific modular architecture and the possibility of a conserved, universal structure.
Emotional learning selectively and retroactively strengthens memories for related events

Neurobiological models of long-term memory propose a mechanism by which initially weak memories are strengthened through subsequent activation that engages common neural pathways minutes to hours later. This synaptic tag-and-capture model has been hypothesized to explain how inconsequential information is selectively consolidated following salient experiences. Behavioural evidence for tag-and-capture is provided by rodent studies in which weak early memories are strengthened by future behavioural training. Whether a process of behavioural tagging occurs in humans to transform weak episodic memories into stable long-term memories is unknown. Here we show, in humans, that information is selectively consolidated if conceptually related information, putatively represented in a common neural substrate, is made salient through an emotional learning experience. Memory for neutral objects was selectively enhanced if other objects from the same category were paired with shock. Retroactive enhancements as a result of emotional learning were observed following a period of consolidation, but were not observed in an immediate memory test or for items strongly encoded before fear conditioning. These findings provide new evidence for a generalized retroactive memory enhancement, whereby inconsequential information can be retroactively credited as relevant, and therefore selectively remembered, if conceptually related information acquires salience in the future.
Verifying Program Performance

It is shown that specifications of program performance can be formally verified. Formal verification techniques, in particular, the method of inductive assertions, can be adapted to show that a program's maximum or mean execution time is correctly described by specifications supplied with the program. To formally establish the mean execution time, branching probabilities are expressed using inductive assertions which involve probability distributions. Verification conditions are formed and proved which establish that if the input distribution is correctly described by the input specifications, then the inductive assertions correctly describe the probability distributions of the data during execution. Once the inductive assertions are shown to be correct, branching probabilities are obtained and mean computation time is computed.
Managing Fish Hatchery Phosphorus Discharge through Facility Design and Waste Solids Management: A Field Assessment in Nearshore Oneida Lake, New York

Abstract The discharge of phosphorus from fish hatcheries to receiving waters has often been associated with nuisance algal growth. The objective of this study was to evaluate the effect of phosphorus from a newly constructed public fish hatchery (known as the Oneida Fish Culture Station or OFCS) on Cladophora abundance in nearshore areas of Oneida Lake, New York. Our approach was to monitor total phosphorus (TP) and soluble reactive phosphorus (SRP) above and below the OFCS (on Scriba Creek) and at a reference site (Murray Creek) and to index Cladophora abundance at nearshore areas surrounding both streams from late April to early October 1993–1995. The OFCS has a unique particulate disposal system that involves the settling and subsurface leaching of supernatant to minimize phosphorus discharges. The amount of phosphorus entering Scriba Creek annually from the OFCS was estimated to be less than 38 kg. Although concentrations of TP and SRP tended to be higher downstream of the OFCS, these higher levels w...
Mesoscopic tomography imaging of reporter genes in thick printed tissue constructs

We report an application of Mesoscopic Fluorescence Molecular Tomography to 3D tissue engineering construct. Engineered thick tissue was hosting two 3D printed vasculatures. The channels were formed by live cells, expressing GFP and mCherry reporter genes, embedded in 3mm turbid media. Tissue and cells kept in a 3mm thick perfusion chamber during the entire imaging process which took less than 5 minutes.
Timing Is Everything – Delaying Therapy for Delayed Cell Death

Damage after a hypoxic-ischemic (HI) insult is both region and cell population specific [Johnston, 1998]. This observation is critically evident in, and important to, the pathogenesis of the insult in
Alteration of Fibroblast Cell Behavior due to Contraction of Substrate

Many researchers have utilized hydrogels as substrates for cell attachment. The stiffness of these substrates has been found to influence the cellular behavior such as morphology, proliferation, growth and differentiation. Lo et al. deformed polyacrylamide substrates with a blunted microneedle and observed the movement of NIH 3T3 fibroblasts. In both pulling and pushing, the cells reversed their direction and moved away from the needle. This shows that cellular behavior is also affected by stretching the underlying substrates. In a previous study, Lin et al. have demonstrated the ability to contract DNA-crosslinked polyacrylamide hydrogels (‘DNA gels’ in short) by addition of crosslinks. Jiang et al. have utilized these DNA gels as substrates to observe the cellular responses of L929 and GFP fibroblasts to both static and dynamic substrate compliances.Copyright © 2010 by ASME
Evidence for carbocation formation during the coadsorption of methanol and hydrogen on Pt(110)

Abstract There are reasons to suspect that carbocations can form during hydrocarbon adsorption on metal surfaces, but so far no one has observed a carbocation on any metal surface spectroscopically. In this paper, we examine the coadsorption of methanol and hydrogen on Pt(110) to see whether a methoxonium species [CH 3 OH 2 ] + can form. We find that a new species does form when we coadsorb hydrogen and methanol on Pt(110) at 100 K and then heat to 200 K. The new species has an EELS spectrum which is consistent with the one expected for a methoxonium ion, and has the isotopic shifts expected for methoxonium. Comparison to the EELS spectrum estimated from ab initio calculations is used to verify the EELS assignment, and to rule out the possibility that a methoxonium radical or other similar species is formed instead. We also observe the chemistry expected when a carbocation forms (i.e. dehydration). These results provide strong evidence that methoxonium forms when hydrogen and methanol coadsorb on platinum. This is the first time that a carbocation has been observed spectroscopically on a metal surface.
Current trends in multiple sclerosis research

Byron Waksman discusses existing evidence which suggests that MS occurs in genetically predisposed individuals manifesting defects in immune regulation. It appears to be triggered by viral infection and to be virus or autoimmune in nature. Abnormalities in circulating immunoregulatory cells are very well correlated with disease activity. Animal models closely resembling MS also involve chronic virus or autoimmune disease in animals with a genetically determined abnormality of immune regulation.
The interaction between endothelium-derived relaxing factor (EDRF) and eicosanoids in the regulation of the mesenteric microcirculation.

Abstract Locally produced eicosanoids and endothelium-derived factors are believed to be the mediators of vascular tone of various vascular beds including the mesentery. Using a small vessel isometric myograph which allows direct measurement of microvascular reactivity, the interaction of eicosanoids and endothelium-derived relaxing factor (EDRF) in regulating vascular tone of mesenteric microcirculation of the rat was characterized. The microvascular response to various vasoactive agents before and after inhibition of prostacyclin production with indomethacin (INDO, 5 μM) and inhibition of EDRF synthesis with N ω-nitro-dcl026;-arginine methyl ester (dcl026;-NAME, 50 μM) was compared. Analysis of dose-response curves for prostaglandin F 2α (PGF 2α ), U46619, a stable thromboxane analog, and norepinephrine (NE) after pretreatment with INDO demonstrated that inhibition of endogenous eicosanoids significantly attenuated the vasoconstrictor response to PGF 2α and U46619 but not to NE. Inhibition of EDRF synthesis with dcl026;-NAME potentiated the vasoconstrictor response to PGF 2α , U46619, and NE. These results suggest that EDRF acts as the primary mediator of vasodilator tone in the mesenteric microcirculation rather than vasodilator cyclooxygenase products such as prostacyclin. It also appears that the vasoconstrictor action of PGF 2α and U46619 may be mediated by a release of an endogenous indomethacin-sensitive factor.
Changes in diurnal temperature range and national cereal yields

Models of yield responses to temperature change have often considered only changes in average temperature (Tavg) with the implicit assumption that changes in the diurnal temperature range (DTR; the difference between daily maximum and minimum temperature) can safely be ignored. The goal of this study was to evaluate this assumption using a combination of historical datasets and climate model projections. Data on national crop yields for 1961–2002 in the ten leading producers of wheat (Triticum spp.), rice (Oryza spp.) and maize (Zea mays) were combined with datasets on climate and crop locations to evaluate the empirical relationships between Tavg, DTR and crop yields. In several rice and maize growing regions, including the two major nations for each crop, there was a clear negative response of yields to increased DTR. This finding reflects a nonlinear response of yields to temperature, which likely results from greater water and heat stress during hot days. In many other cases, the effects of DTR were not statistically significant, in part because correlations of DTR with other climate variables, and the relatively short length of the time series resulted in wide confidence intervals for the estimates. To evaluate whether future changes in DTR are relevant to crop impact assessments, yield responses to projected changes in Tavg and DTR by 2046–2065 from 11 climate models were estimated. The mean of climate model projections indicated an increase in DTR in most seasons and locations where wheat is grown, mixed projections for maize, and a general decrease in DTR for rice. These mean projections were associated with wide ranges that included zero in nearly all cases. The estimated impacts of DTR changes on yields were generally small (<5% change in yields) relative to the consistently negative impact of projected warming of Tavg. However, DTR changes did significantly affect yield responses in several cases, such as in reducing US maize yields and increasing India rice yields. Because DTR projections tend to be positively correlated with Tavg, estimates of yield changes for extreme warming were particularly affected by including DTR (up to 10%). Finally, based on the relatively poor performance of climate models in reproducing the magnitude of past DTR trends, it is possible that future DTR changes and associated yield responses will exceed the ranges considered here.
Implications of the red-shift-number test for cosmology

This Letter discusses the recent measurement of the number of galaxies versus red shift and flux for cosmological models with a nonzero cosmological constant $\ensuremath{\Lambda}$ and pressureless matter. The main conclusions are these: (1) If space is flat as the inflationary model predicts, then the density parameter $\ensuremath{\Omega}={0.9}_{\ensuremath{-}0.2}^{+0.4}$ and $\frac{\ensuremath{\Lambda}}{(3{H}_{0}^{2})}={0.1}_{\ensuremath{-}0.4}^{+0.2}$. (95%-confidence intervals are used throughout.) (2) For both inflationary and $\ensuremath{\Lambda}=0$ models, the present result and primordial nucleosynthesis are consistent only if a large density of nonbaryonic matter exists. (3) Without any assumptions about $\ensuremath{\Lambda}$, the age of the Universe $t$ and Hubble's constant ${H}_{0}$ are constrained by $0.60lt{H}_{0}l0.88$.
Percolation Thresholds for Diffusing Particles of Nonzero Radius: Circular Obstacles in the Two-dimensional Continuum

Lateral diffusion in the plasma membrane is obstructed by proteins bound to the cytoskeleton. The most important parameter describing diffusion in the presence of immobile obstacles is the percolation threshold, where long-range connected paths disappear and the long-range diffusion coefficient D goes to zero. To describe obstructed diffusion, it is more accurate to find the threshold directly than to extrapolate a low-density expansion in the obstacle concentration to find the concentration at which D = 0. The thresholds are well-known for point diffusing particles on various lattices or the continuum. But for particles of nonzero radius, the threshold depends on the excluded area, not just the obstacle concentration. Earlier results [Saxton, Biophys J 64 (1993) 1053] for the triangular lattice showed a very rapid decrease in the threshold as the radius of the diffusing particle increases, but a lattice model gives very low resolution. The current work finds the percolation threshold for circular obstacles in the two-dimensional continuum as a function of the radius of the diffusing species. The thresholds are obtained by a Monte Carlo method based on the Voronoi diagram for the obstacles. Each Voronoi bond is by definition the path equidistant from the nearest pair of obstacles, so the separation of that pair determines whether a diffusing particle of a given diameter can traverse that bond. For point obstacles, then, one can choose a threshold corresponding to the diameter of the diffusing particle, set the conductivity of all bonds narrower than that diameter to zero and all wider bonds to one, and test for bond percolation on the resulting Voronoi diagram. The results are used to find the thresholds for lipids and for proteins of different diameters. (Supported by NIH grant GM038133)
Improved Greedy Algorithms for Sparse Approximation of a Matrix in Terms of Another Matrix

We consider simultaneously approximating all the columns of a data matrix in terms of few selected columns of another matrix that is sometimes called “the dictionary”. The challenge is to determine a small subset of the dictionary columns that can be used to obtain an accurate prediction of the entire data matrix. Previously proposed greedy algorithms for this task compare each data column with all dictionary columns, resulting in algorithms that may be too slow when both the data matrix and the dictionary matrix are large. A recent approach for accelerating the run time requires large amounts of memory to keep temporary values during the run of the algorithm. We propose two new algorithms that can be used even when both the data matrix and the dictionary matrix are large. The first algorithm is exact, with output identical to some previously proposed greedy algorithms. It takes significantly less memory when compared to the current state-of-the-art, and runs much faster when the dictionary matrix is sparse. The second algorithm uses a low rank approximation to the data matrix to further improve the run time. The algorithms use new recursive formulas for computing the greedy selection criterion. The formulas enable decoupling most of the computations related to the data matrix from the computations related to the dictionary matrix.
Grazing effects on forb diversity and abundance in a honey mesquite parkland

Abstract Livestock grazing is the most common use of rangelands, and overgrazing by domestic livestock has stirred much debate concerning the continued use of public rangelands for livestock production. With the increase of wildlife-related enterprises on south Texas rangelands, there are little data available on the compatibility of livestock and wildlife management and in particular the effects of livestock grazing on plant communities in the semi-arid portions of the western South Texas Plains. The objective of this study was to compare forb diversity and density on rangelands subjected to various grazing under a high-intensity, low-frequency grazing system and nongrazed rangelands under controlled conditions. Four rangeland sites that were moderately grazed during the dormant season and 4 rangeland sites receiving long-term deferment from grazing were selected on the Chaparral Wildlife Management Area, Dimmit and La Salle Counties, Texas. Forb density was estimated with 20×50 cm 2 quadrats during early spring 2000 and 2001. Forb diversity was greatest on grazed sites. Important annuals such as hooker plantain ( Plantago hookeriana ) and Rough buttonweed ( Diodia teres ) were more prevalent on grazed sites. Lazy daisy ( Aphanostephus spp.) was more frequently encountered on nongrazed sites. Golden dalea ( Dalea aurea ), a beneficial perennial, was more common on grazed sites. Long-term deferment from livestock grazing appears detrimental to forb communities. A high-intensity, low-frequency grazing system utilizing moderate stocking rates employed during the dormant season is recommended for enhancing forb diversity and abundance.
Changes in the volume, form and internal architecture of the nuclei of the granular glands of the integument of the newt, Triturus viridescens

Concomitant with the appearance of the early secretion granules the nucleus enlarges slightly, the basichromatin is reduced and discrete acidophilic granules appear within the nuclei. Some nuclei become vacuolated and in others the basichromatin is practically reduced to a thin shell reinforced with occasional chromatic strands. Such nuclei are filled with acidophilic granules. In many instances the portion of the nucleus adjacent to the secretion is greatly modified, the basichromatin is reduced and presents an alveolar pattern with the alveoli filled with acidophilic material and elongated at right angles to the nuclear membrane. This appearance suggests that material is passing from the nucleus into the cytoplasm but no cytological evidence of such a passage was obtained. During the storage phase giant nuclei are present. They appear to be the result of a simple hypertrophy but in a few instances it appeared that multiplication by direct division, followed by coalescence might be a contributory factor to their formation. Following thyroidectomy or hypophysectomy the production of secretion was retarded but no profound regression was observed. After treatment with implants or injections of anterior pituitary a mild stimulation was observed. The evidence for nuclear participation in the formation of secretion is not conclusive but many of the changes which occur strongly suggest such an activity.
Becoming "Black Lambs" Not "Parrots": A Poststructuralist Orientation to Intelligibility and Identity

How do international speakers of English assert their identities as legitimate teachers of English given the privileged position of the native speaker? To answer this question, we present case studies of two students from Taiwan in their first year of study in a 2-year master of arts in TESOL (MATESOL) program. The data included interviews after the course and reaction papers written in a pronunciation pedagogy course in response to readings that challenged the native speaker myth. Using a poststructuralist concept of identity to frame the data, we found that these preservice teachers, not surprisingly, had multiple and conflicting identities as legitimate speakers and teachers of English. Though deeply influenced by the native speaker myth and educational practices that equate Whiteness with native speakers, these teachers were able to appropriate and imagine new identities as legitimate speakers and teachers of English through the linguistic resources provided by the course readings. These teachers also recognized that they had other means, besides native-like pronunciation, to establish their legitimacy. We argue that the value of teacher education lies in its ability to offer alternative discourses, for example multicompetence (Cook, 1992), to enable preservice teachers to imagine alternative identities. In imagining these identities, teacher learners can also develop alternative instructional practice, practice that may be contrary to the norms of the educational institutions in which they work.
Maximizing the benefit of minimally invasive surgery

Minimal invasive surgery is an excellent approach for the diagnosis and treatment of a wide range of thoracic disorders that previously required sternotomy or open thoracotomy. The notable benefits of minimal invasive surgery to patients include less postoperative pain, fewer operative and post-operative major complications, shortened hospital stay, faster recovery times, less scarring, less stress on the immune system, smaller incision, and for some procedures reduced operating time and reduced costs.
The enthalpy of the isotope-exchange reaction: H2O + D2O = 2HDO at temperatures to 673 K and at pressures to 40 MPa

Abstract The enthalpy of mixing of {(1 − x)H2O + xD2O} was measured at temperatures from 310 K to 673 K at pressures from 7 MPa to 37 MPa with a flow calorimeter. Thermodynamic quantities for the isotope-exchange reaction: H2O + D2O = 2HDO were calculated from these results, assuming ideal mixing of the products and reactants. A slight asymmetry with x of the mixing enthalpies, observed at higher temperatures, is not considered sufficient to assign values of excess enthalpies of mixing. The equilibrium constant K increased from 3.82 at 298.15 K and 0.1 MPa to 3.93 at 673.15 K at 37 MPa, while ΔrHmo decreased from 129.4 J·mol−1 to 67.5 J·mol−1. The statistical limit K = 4.0 was not attained in the high-temperature limit of the present study.
Space Systems Flexibility Provided by On-Orbit Servicing: Part 1

Spacecraft are still the only complex engineering systems without routine maintenance infrastructure. Whereas the technologies for autonomous on-orbit servicing of satellites are emerging, no general conclusions have yet been drawn regarding the cost effectiveness of on-orbit servicing. In a companion paper (Saleh, J. H., Lamassoure, E., and Hastings, D. E., "Space Systems Flexibility Provided by On-Orbit Servicing: Part 1," Journal of Spacecraft and Rockets, Vol. 39, No. 4, 2002, pp. 551-560), a new perspective on the problem was proposed, in which the value of servicing is studied independently from its cost. A framework to account for the value of the flexibility provided by on-orbit servicing to space systems was developed. Here, the usefulness of this framework is demonstrated by studying the value of servicing for two types of space missions. First commercial missions with uncertain revenues are considered. It is shown that traditional valuation has been underestimating mission value by not taking into account the option to abandon. Then servicing is considered as an option on life extension, showing how the optimal design life decreases with increasing uncertainty. A map of the maximum servicing price in a market level/market volatility space is proposed as a new tool for decision making. Then military missions faced with uncertainty in the location of contingencies are considered. The value of refueling for making spacecraft maneuverable is studied for two cases. For a radar constellation in low Earth orbit, servicing is shown to have little value due to a conflict between propulsion mass and maneuver time. For a geostationary fleet of communication satellites, servicing is shown to have value based on the potential improvements in capacity usage.
Mechanism of Trail-laying in Two Species of Termites

DURING recent investigations on the behaviour of the primitive termite Zootermopsis nevadensis (Hagen), evidence for trail-laying was obtained when it was noted that nymphs accurately followed the path taken by one nymph over a clear unobstructed surface in an artificial nest, even when the direction of the light and the position of the nest were altered. This, to my knowledge, is the first mention of trail-laying in a lower termite.
A learning-based autonomous driver: emulate human driver's intelligence in low-speed car following

In this paper, an offline learning mechanism based on the genetic algorithm is proposed for autonomous vehicles to emulate human driver behaviors. The autonomous driving ability is implemented based on a Prediction- and Cost function-Based algorithm (PCB). PCB is designed to emulate a human driver's decision process, which is modeled as traffic scenario prediction and evaluation. This paper focuses on using a learning algorithm to optimize PCB with very limited training data, so that PCB can have the ability to predict and evaluate traffic scenarios similarly to human drivers. 80 seconds of human driving data was collected in low-speed (< 30miles/h) car-following scenarios. In the low-speed car-following tests, PCB was able to perform more human-like carfollowing after learning. A more general 120 kilometer-long simulation showed that PCB performs robustly even in scenarios that are not part of the training set.
Learning and vision machines

The problem of learning is arguably at the very core of the problem of intelligence, both biological and artificial. In this paper we review our approach to the problem of visual perception based on supervised learning. After a brief presentation of the theoretical background, we focus on some of the engineering applications of statistical learning to computer vision and discuss the main open problems and directions of our future research.
The impact of varying patient populations on the in-control performance of the risk-adjusted CUSUM chart

Objective: This research is designed to examine the impact of varying patient population distributions on the in-control performance of the risk-adjusted Bernoulli CUSUM chart. Design: The in-control performance of the chart is compared based on sampling the Parsonnet scores with replacement from five realistic subsets of a given distribution. Settings: Five patient mixes with different Parsonnet score distributions are created from a real patient population. Main Outcome Measures: The outcome measures for this research are the in-control average run lengths (ARLs) given varying patient populations. Results: Our simulation results show that the in-control ARLs of the risk-adjusted Bernoulli CUSUM chart with fixed control limits and a given risk-adjustment equation vary significantly for different patient population distributions, and the in-control ARLs decrease as the mean of the Parsonnet scores increases. Conclusions: The simulation results imply that the control limits should vary based on the particular patient population of interest in order to control the in-control performance of the risk-adjusted Bernoulli CUSUM method.
Direct exposure of mammalian cells to pure exogenous singlet oxygen (1 delta gO2).

Mammalian cells attached to membrane filters or deposited on filters without attachment were exposed to gas-phase singlet oxygen (1O2) in the absence of any other reactants. Cells were exposed in a monolayer or less, in the absence of external medium, during steady-state 1O2 generation, ensuring that singlet oxygen impinged directly and equally on all cells simultaneously. The current methodology for cell exposure ensures that 1O2 is initially the only reactive species to which the cells are exposed. Results seen with this system can therefore be attributed solely and unambiguously to events initiated by 1O2. Further, all cells in the sample receive the same magnitude of exposure per surface area per time interval, which supports calculations of the amount of 1O2 required for irreversible cell damage, based on measured 1O2 flux and exposed cell surface area. Exposure to pure 1O2 irreversibly damaged a variety of cell types, including rat basophilic leukemia, human squamous carcinoma and Chinese hamster lung fibroblast cell lines, and murine primary hepatocytes. Cell survival curves following exposure to 1O2 followed apparent first-order kinetics. A large number of singlet oxygen collisions (approximately 10(12)-10(13) were required to inactivate a cell, on average, indicating a low probability that singlet oxygen collision will reduce cell survival. Regardless of cell type or the survival endpoint measured, lethal toxicity required a fairly constant number of 1O2 collisions per cell. This poses a serious caveat in the assignment of causality in correlating 1O2-initiated cellular damage with mechanism of death, i.e. most damage observed will not be related to death.(ABSTRACT TRUNCATED AT 250 WORDS)
Depression Treatment Enhances Adherence to Antiretroviral Therapy: a Meta-Analysis

Depression is a risk factor for nonadherence to HIV/AIDS treatment. A meta-analysis was conducted to examine whether treatment of depression and psychological distress improves antiretroviral therapy adherence. PubMed and PsycINFO databases were systematically searched for relevant articles. Studies that reported an association between depression treatment (or an intervention with a component addressing mental health) and antiretroviral adherence were included. Across 29 studies of 12,243 persons living with HIV/AIDS, treatment of depression and psychological distress improved antiretroviral adherence (p < 0.001). The odds of a person adhering were 83 % better if he/she was treated for depression. Greater improvements in adherence were found for samples with lower CD4 counts or more severe depression, for interventions specifically targeting depression (versus addressing mental health as a secondary objective), longer treatments, and observational studies. These findings support the need for detection and treatment of depression among persons living with HIV/AIDS.