cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Worldline Casting of the Stochastic Vacuum Model and Non-Perturbative Properties of QCD: General Formalism and Applications
Creators: name: Karanikas, A. I.
name: Ktorides, C. N.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The Stochastic Vacuum Model for QCD, proposed by Dosch and Simonov, is fused with a Worldline casting of the underlying theory, i.e. QCD. Important, non-perturbative features of the model are studied. In particular, contributions associated with the spin-field interaction are calculated and both the validity of the loop equations and of the Bianchi identity are explicitly demonstrated. As an application, a simulated meson-meson scattering problem is studied in the Regge kinematical regime. The process is modeled in terms of the "helicoidal" Wilson contour along the lines introduced by Janik and Peschanski in a related study based on a AdS/CFT-type approach. Working strictly in the framework of the Stochastic Vacuum Model and in a semiclassical approximation scheme the Regge behavior for the Scattering amplitude is demonstrated. Going beyond this approximation, the contribution resulting from boundary fluctuation of the Wilson loop contour is also estimated.
description: 37 pages, 1 figure. Final version to appear in Phys.Rev.D
title: The Development of an Improved Milk Substrate for Rennet Coagulation Assay on an Automatic Clot-Timer
Creators: name: Stevens, Mark Brimhall
Publisher: name: Utah State University
Year: 1973

description: A substrate was developed for measuring the milk clotting strength of rennet preparations on an automatic clot-timer . The substrate contained 8 percent pasteurized skim milk solids, 1 percent chloroform, 0.3 percent 200 bloom gelatin, 0.03 M added CaCl2 and was buffered to pH 6.6 with 0.057 M cacodylic acid and 0.042 M triethanolamine. The substrate was shelf-stable for 18 days at room temperatures. It was found that rennet preparations could be standardized to within 1 percent of each other, in terms of milk clotting strength, by use of the substrate on the automatic clot-timer. The method appears to have advantages over conventional rennet standardizing procedures. The research included studies on the effect of chloroform, nonfat dry milk and CaCl2 concentrations; heat and ionizing radiation on the substrate coagulation time.
Time-Dependent Duhamel Renormalization method with Multiple Conservation and Dissipation Laws
Creators: name: Chandramouli, Sathyanarayanan
name: Farhat, Aseel
name: Musslimani, Ziad
Publisher: name: arXiv
Year: 2022
Subjects: subject: Numerical Analysis (math.NA)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: The time dependent spectral renormalization (TDSR) method was introduced by Cole and Musslimani as a novel way to numerically solve initial boundary value problems. An important and novel aspect of the TDSR scheme is its ability to incorporate physics in the form of conservation laws or dissipation rate equations. However, the method was limited to include a single conserved or dissipative quantity. The present work significantly extends the computational features of the method with the (i) incorporation of multiple conservation laws and/or dissipation rate equations, (ii) ability to enforce versatile boundary conditions, and (iii) higher order time integration strategy. The TDSR method is applied on several prototypical evolution equations of physical significance. Examples include the Korteweg-de Vries (KdV), multi-dimensional nonlinear Schrödinger (NLS) and the Allen-Cahn equations.
Forbidden question : a history of the limits to growth debate
Creators: name: Higgs, KA
Publisher: name: University Of Tasmania
Year: 2023

description: This thesis investigates the history of the debate about the limits to economic growth. It asks how it came about that the emerging concerns of natural scientists and physical modellers were scorned by economists and, at least after 1980, largely ignored by governments and policy-makers world-wide. The unprecedented character of economic growth in the twentieth century is examined and its roots, scale and relationship to cheap energy is analysed, as well as the conflict between the pre-analytic assumptions of the two disciplines most concerned with the debate-economics and the natural sciences. The increasingly self-conscious pursuit of economic growth is explored as is the process by which growth was adopted as the self-evident solution to all social problems, .displacing ideas about equity and fairness. It is argued that the newly consolidated corporations that emerged in the US at the tum of the twentieth century progressively banded together to sell not just their products but 'free enterprise' itself, a system tied to ever-continuing growth. That investigation gives rise to a history of corporate ideological campaigns against organised labour, democratic oversight and government 'interference', especially regulation and taxation-campaigns readily adapted to resisting environmental priorities. The thesis examines how these established techniques-propaganda and the straightforward buying of influence-were augmented after 1970 by the construction of a vast research apparatus dedicated to business interests and values, and designed to exert determinate influence over government policy. Its sources of funding and expertise are explored. It is argued that this institutional expansion has been instrumental in naturalising and strengthening the economic paradigm, 'mysteriously' detached from the physical world on which it relies, giving economists pre-eminent influence within governments and bureaucracies and turning the pursuit of economic growth into everyday common sense.
Quantization of Black Hole Entropy from Quasinormal Modes
Creators: name: Wei, Shao-Wen
name: Li, Ran
name: Liu, Yu-Xiao
name: Ren, Ji-Rong
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In Phys. Rev. D 78 (2008) 104018 [arXiv:0807.1481], the conclusion that "entropy eigenvalues of GB black hole are discrete and equally spaced, but the area spacing is not equidistant" was firstly presented by Kothawala, Padmanabhan and Sarkar. In this paper, using the new physical interpretation of quasinormal modes proposed by Maggiore, we calculate the quantum spectra of entropy for various types of non-rotating black holes with no charge. The spectrum is obtained by imposing Bohr-Sommerfeld quantization condition to the adiabatic invariant quantity. We conjecture that the spacing of entropy spectrum is equidistant and is independent of the dimension of spacetime. However, the spacing of area spectrum depends on gravity theory. In Einstein's gravity, it is equally spaced, otherwise it is non-equidistant. This conjecture agrees with the result of Kothawala, Padmanabhan and Sarkar.
description: V3: 10 pages, the revised version emphasizes that the same result has been obtained earlier in Phys.Rev.D78(2008)104018[arXiv:0807.1481]
title: Influence of Temperature and Rate of Heat Penetration on Some Factors in Charcoal Broiled Porterhouse Steak and Ground Beef
Creators: name: Irvine, Geraldine
Publisher: name: Utah State University
Year: 1963

description: Charcoal broiling is becoming an increasingly popular method for cooking meat. Little scientific work has been done in this area. Information presently available on charcoal broiling consists of broad generalizations which have developed from trial and error testing. With the current interest in charcoal broiling, there is a need for more factual, scientific information as to the proper procedure.
Cooking method affects palatability and nutritive value of meat. Chemical and physical changes occur during the cooking process and the reactions which take place are not fully known or understood. Each cooking method has a specific effect upon meat due to the rate of heat penetration and the reactions which take place during the cooking period.
Broiling usually takes place at high temperature, making this method of cooking meat contrary to recommendations . Generally broiling is done with the thermostat set at 500 F . The heating element is constantly energized when turned on. Attempts are made to adjust to the desired temperature by varying the distance from the heat source. Cover et al. (1957) showed actual surface temperature of the broiler often fluctuated from the desired temperature. Preliminary testing in our laboratory showed that it was impossible to regulate heat at a constant temperature with an electric broiler.
Signal-Aware Direction-of-Arrival Estimation Using Attention Mechanisms
Creators: name: Mack, Wolfgang
name: Wechsler, Julian
name: Habets, Emanuël A. P.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Audio and Speech Processing (eess.AS)
subject: Sound (cs.SD)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: The direction-of-arrival (DOA) of sound sources is an essential acoustic parameter used, e.g., for multi-channel speech enhancement or source tracking. Complex acoustic scenarios consisting of sources-of-interest, interfering sources, reverberation, and noise make the estimation of the DOAs corresponding to the sources-of-interest a challenging task. Recently proposed attention mechanisms allow DOA estimators to focus on the sources-of-interest and disregard interference and noise, i.e., they are signal-aware. The attention is typically obtained by a deep neural network (DNN) from a short-time Fourier transform (STFT) based representation of a single microphone signal. Subsequently, attention has been applied as binary or ratio weighting to STFT-based microphone signal representations to reduce the impact of frequency bins dominated by noise, interference, or reverberation. The impact of attention on DOA estimators and different training strategies for attention and DOA DNNs are not yet studied in depth. In this paper, we evaluate systems consisting of different DNNs and signal processing-based methods for DOA estimation when attention is applied. Additionally, we propose training strategies for attention-based DOA estimation optimized via a DOA objective, i.e., end-to-end. The evaluation of the proposed and the baseline systems is performed using data generated with simulated and measured room impulse responses under various acoustic conditions, like reverberation times, noise, and source array distances. Overall, DOA estimation using attention in combination with signal-processing methods exhibits a far lower computational complexity than a fully DNN-based system; however, it yields comparable results.
The effect of mode specific treatment on anxiety : an analogue study
Creators: name: Midford, Richard G
Publisher: name: University Of Tasmania
Year: 2023

description: The present study examined Davidson and Schwartz's (1976) model of multi modal anxiety and treatment. Initially various theoretical conceptions of anxiety, were reviewed. This was followed by an outline of multi modal conceptions of anxiety and relaxation. Davidson and Schwartz's model was presented in some detail. The thesis of these authors derives from the assumption that anxiety can be divided into two relatively independent modes: cognitive and somatic. The therapeutic corollary of this conception of anxiety is that persons manifesting the phenomenon in a particular mode would gain maximum relief if they received treatment which induced further activation of a neutral nature in that mode. Additionally the model holds that mode specific activation also reduces unwanted activity in other modes, albeit to a lesser extent. These propositions were tested using the following experimental design. Two groups of female subjects were selected on the basis of the predominant mode in which they manifested their anxiety: cognitive or somatic. Each group was then further partitioned on the basis of the treatment applied. Equal numbers of cognitive and somatic subjects were allocated to cognitive treatment, somatic treatment, and no treatment (control) conditions. Data from the Taylor Manifest Anxiety Scale, and three physiological response measures: skin conductance; finger blood volume; and finger pulse amplitude were interpreted as providing support for Davidson and Schwartz's (1976) treatment specificity thesis. The somatic technique used in this study was found to be particularly effective in reducing somatic anxiety. In conclusion, possible directions of future research and the implications of this study's findings for clinical treatment of anxiety were discussed.
Photometric Study of W UMa Type Binaries in the Old Open Cluster Berkeley 39
Creators: name: Sriram, K.
name: Kiron, Y. Ravi
name: Rao, P. Vivekananda
Publisher: name: arXiv
Year: 2009
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The study of W UMa binary systems give a wealth of information about its nature as well as about its parent body (if any), like clusters. In this paper, we present the I passband photometric solutions of four W UMa binaries in the open cluster Berkeley 39 using the latest version of WD program. The result shows that, two binary systems are W subtype W UMa binary systems and another two systems are H subtype W UMa binary systems. No third body is found in any of the four systems. We found a correlation between the period and mass-ratio as well as temperature and mass-ratio for the respective variables which is similar to the relationship between mass ratio and total mass of the contact binaries as shown by vant Veer (1996) and Li et al. (2008).
description: 8 pages, 2 figures, accepted for the publication in RAA
Cutting a part from many measures
Creators: name: Blagojevic, Pavle V. M.
name: Palic, Nevena
name: Soberon, Pablo
name: Ziegler, Günther M.
Publisher: name: Freie Universität Berlin
Year: 2019
Subjects: subject: Mathematics
subject: FOS: Mathematics
subject: 500 Naturwissenschaften und Mathematik::510 Mathematik::510 Mathematik

description: Holmsen, Kyncˇl and Valculescu recently conjectured that if a finite set X with in points in Rd that is colored by m different colors can be partitioned into n subsets of i points each, such that each subset contains points of at least d different colors, then there exists such a partition of X with the additional property that the convex hulls of the n subsets are pairwise disjoint. We prove a continuous analogue of this conjecture, generalized so that each subset contains points of at least c different colors, where we also allow c to be greater than d. Furthermore, we give lower bounds on the fraction of the points each of the subsets contains from c different colors. For example, when n ≤ 2, d ≤ 2, c ≤ d with m ≤ n(c - d) d are integers, and µ1, . . . ,µm are m positive finite absolutely continuous measures on Rd , we prove that there exists a partition of Rd into n convex pieces which equiparts the measures µ1, . . . ,µd−1, and in addition every piece of the partition has positive measure with respect to at least c of the measures µ1, . . . ,µm . 2010 Mathematics Subject Classification: 52C35, 51M20 (primary); 55R20, 55N25 (secondary)
FVa inactivation by APC and protein S
Creators: name: Gierula, Magdalena Maria
Publisher: name: Imperial College London
Year: 2018

description: Factor Va enhances thrombin generation by several orders of magnitude. Its function is controlled by activated protein C (APC)-mediated and protein S enhanced proteolysis. The aim of my thesis was to clarify the molecular mechanisms underlying FVa inactivation. For this, all three proteins were recombinantly produced and characterised. As APC-mediated FVa inactivation is phospholipid dependent, assays were optimised to investigate interactions in the presence of phospholipids. I have shown that protein S and FVa act together to enhance APC association with phospholipid membranes. The presence of protein S is mandatory, as FVa by itself does not increase binding of APC to phospholipids. These findings strongly suggest that APC, protein S and FVa together form an inactivation complex on phospholipid surfaces. Unlike FVa, FVIIIa does not enhance APC binding to phospholipids, indicating that FVIIIa does not form a similar complex with APC and protein S. C4BP-bound protein S did not efficiently enhance APC-phospholipid binding, indicating that C4BP interfers with complex formation. Results I obtained with protein S variants with impared APC cofactor function, and FV Nara, associated with strong APC resistance, indicate that their mutations essentially abolished their ability to assemble into the tri-molecular complex. FV-810, with partial B-domain deletion, assembled the complex as efficiently as FVa. Protein S was required for complex enhancement by FV-810. However, results for FV-810 obtained with a FVa inactivation assay indicated that effective inactivation can be achieved in the absence of protein S. These findings suggest that there must be an alternative mechanism involved in APC cofactor function which is not mediated solely by increased binding of APC to phospholipids. In conclusion, my findings demonstrate that FVa promotes its own APC-mediated degradation by enhancing APC binding to phospholipids together with protein S, but also suggest that more than a single mechanism controls FVa inactivation.
Low-power optical bistability in $\mathcal{PT}$-symmetric chirped Bragg gratings with four-wave mixing
Creators: name: Sudhakar, S.
name: Raja, S. Vignesh
name: Govindarajan, A.
name: Batri, K.
name: Lakshmanan, M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optics (physics.optics)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: The central theme of this article is the analysis of the usefulness of introducing four-wave mixing or modulation of Kerr nonlinearity in a nonuniform grating structure with gain and loss. To do so, we propose an inhomogeneous system in which the nonlinearity of the $\mathcal{PT}$-symmetric grating is modulated. It is proven that the proposed scheme can be fruitful only if the nonlinearity and its associated modulation terms are assumed to be self-defocusing ones. In order to cut down the intensity required for the steering, the sign of chirping is taken to be negative and the wavelength of operating light is considered to be higher than the Bragg wavelength. Alongside these settings, launching the light from the rear end of the device dramatically reduces the critical intensity to a value of 0.015 (approximately) which must be the lowest switching intensity ever reported in the context of nonlinear $\mathcal{PT}$-symmetric gratings. The ramp-like stable states in the broken $\mathcal{PT}$-symmetric regime prevail even in the company of modulation in the nonlinearity index for both of the light incident directions.
description: To appear in JOSA B
Constrained Hartree-Fock wave functions for atoms
Creators: name: Qureshi, Hilal Ahmed
Publisher: name: University of British Columbia
Year: 2011

description: This thesis deals with the calculation of Hartree-Fock wave functions satisfying an off-diagonal hypervirial relation as a constraint. The constraint in this case implies that the dipole length form and the dipole velocity form of the transition probability give identical values. Mathematically, this is equivalent to forcing the approximate eigenfunctions of the Hamiltonian of the system to satisfy a relation which is true for exact eigenfunctions. The method of constrained variation is used to solve this problem. The constrained Hartree-Fock system of equations is solved numerically. The Z-expansions of radial wave functions, the diagonal and the off-diagonal energy parameters and the parameter of constraint are carried out. The effect of the constraint on the total energy E of the system, defined as the change in the Hartree-Fock total energy due to the constraint, is estimated. The method of constrained variation is then applied to a few two, three and four electron systems to calculate the constrained total energy E of the system and also the oscillator strengths of a few of the transitions of the system. The results indicate that the oscillator strengths can be calculated more accurately, at practically no cost of the total energy E, with the aid of the constrained Hartree-Fock functions than with the standard Hartree-Fock functions in all those cases where the correlation effects are not too strong to invalidate the single configuration approximation.
PROTOCOLO INTERNO DE SEGURIDAD Y PREVENCIÓN DE RIESGOS DE BIBLIOTECA CENTRAL
Creators: name: DANNY PACHECO
Publisher: name: Zenodo
Year: 2023
Subjects: SEGURIUDAD
PREVENCIO0N DE RIESGOS
BIBLIOTECA CENRAL UDA

description: Tener a bien resguardar la integridad física y psicológica de quienes laboran en sus dependencias, como también de la comunidad universitaria que visita diariamente la. Biblioteca.
title: Post-Harvest Storage Studies With Selected Fruits
Creators: name: Dhaliwal, Amrik Singh
Publisher: name: Utah State University
Year: 1962

description: It has been estimated that one-fourth of the fresh fruits harvested are never consumed because of spoilage. This spoilage amounts to many thousands of tons of fruits which are valued annually at several million dollars. Several factors are responsible for the post-harvest spoilage of fruits, namely, pathological, physiological, and mechanical. Men in the past have used various methods to control pathological spoilage of foods. The recent development of nuclear radiation, antibiotics, fungicides, and packaging films provides new methods for prolonging the shelf-life of many fruits. These may prove important in countries like India where refrigeration facilities are not readily available and food shortage has always been a problem. Likewise, in the United States, the present-day marketing of fresh fruits has become more and more complex because centers of consumption are increasingly remote from centers of production. To understand physiological and mechanical spoilage of fruits one should know that perishable products are alive, even though the connection with the source of nourishment has been severed. Continued metabolism and increase in respiration result in over-ripeness, physiological decay, and wilting. The deterioration of fruits by the processes of accelerated respiration induced by ripening, physical changes, and subsequent mechanical damage during transit cannot be stopped; but it can be retarded by lowering the temperature, by treating with respiratory inhibitors, and by careful handling.
title: Effects of Physiological Maturation and Storage on Physical and Biochemical Changes in Peach (PRUNUS PERSICA S. and Z.) and Apricot (PRUNUS ARMENIACA L.) Fruits
Creators: name: Deshpande, Pralhadrao Bhimarao
Publisher: name: Utah State University
Year: 1964

description: Peaches and apricots are important fruit crops in Utah. They are shipped to distant markets in Los Angeles, Chicago, New York, and several other places. These fruits may stay in the market channels for 2 to 4 weeks before they reach the consumer, and sometimes are held at the retail center at temperatures as high as 70-90° F. Decay of these fruits has been a serious problem facing shipping agencies, grocery stores, and the roadstand industry (Salunkhe, 1960).
The quality of fresh as well as processed fruit is influenced by the stage of maturity at picking. Bedford and Robertson (1955), and Culpepper et al. (1955) pointed out that there has been a lack of agreement among several investigators as to the stage of maturity at which peaches can be harvested and successfully ripened for processing. The borderline between immature and mature fruit is of accentuated importance in regions where harvesting must occur at an early date to allow for the necessary transport and marketing period. Growers are, therefore, interested in the proper stage of maturity at which to harvest and shippers and retailers are interested in the effective storage to extend the life of the fruit and to promote consumer acceptance.
In the quest for indices to determine the stage of maturity of deciduous fruits many physical, chemical and physiological characteristics have been studied. Firm-ness, ground color, flesh color, acidity, and soluble solids were found to be in decreasing order of correlation with increasing maturity of peaches (Rood, 1957). Conversely it was attributed that flavor, palatability, and maturity of peaches were directly related to soluble solids (Claypool, 1961). Leonard et al. (1953) reported --that the degree of maturity and flavor preference were predictable by soluble solids/acidity especially at lower acidity levels. Similar studies of a limited nature on apricots have been reported by Allen (1932), Strachan et al. (1951), and Luh (1961).
Information is meager on post-harvest ripening of peaches and apricots for fresh-produce marketing. The investigations reported here were conducted to determine the relationship between firmness, acidity, soluble solids, and other biochemical constituents with maturity and storage of the fruits. The studies presented in this dissertation were carried out on peaches (variety Redhaven) and apricots (variety Large Early Montgamet), and include the results for the years 1962 and 1963.
The development of a model and measure of adoptee identity
Creators: name: Midford, SM
Publisher: name: University Of Tasmania
Year: 2023

description: The objective of this study was to develop a model of adoptee identity development and change. Further using the model, to develop a measure of adoptee identity which was psychometrically sound. Following review of the general identity literature the concept of adoptee identity was discussed. Factors such as self esteem, decision to search, relationship with adoptive parents and circumstances of adoptive status disclosure were identified from the adoption literature as related to adoptee identity. The components of adoptee identity were defined and an overall model of adoptee identity was outlined. The adoption literature suggested two alternative forms of this model of adoptee identity and these were called the credulous model and the sceptical model. Using the model, the development of an adoptee identity measure was commenced. The measure was developed following the stages of test construction as outlined by Crocker and Algina (1986). The project was divided into three stages. Study one used a reunion study of 87 adult adoptees recruited via Adoption Jigsaw, W.A. to pilot test a 25 item identity measure based on discussion groups, and literature review. Four factors: Biological Identity, Alienation, Genealogical Concern and Curiosity were found. In Study two these items were expanded to 52 items and were used in a national study of 943 adult adoptees recruited from two sources: Jigsaw/Triangle state groups
Exploring oxetane isosteres for drug discovery through the catalytic generation of Oxetanyl Carbocations
Creators: name: Croft, Rosemary
Publisher: name: Imperial College London
Year: 2018

description: Oxetanes are valuable motifs for modulating the metabolic susceptibility and physicochemical properties of medicinally promising compounds, as well as replacement motifs for carbonyl, gem-dimethyl and methylene units. For this reason, development of methodology to synthesise novel oxetane derivatives through efficient and robust routes is highly desirable. In this thesis, the preparation of novel oxetane scaffolds through the in situ generation of oxetanyl carbocations is explored. First, the preparation of 3,3-diaryloxetanes, designed as isosteres for benzophenone and diarylmethane derivatives, through a catalytic Friedel–Crafts reaction is described. Using a lithium catalyst, 3,3-diaryloxetanes and dihydrobenzofuran scaffolds are both selectively prepared in one step by reaction of oxetan-3-ols with phenols. A scope of both scaffolds is exemplified along with further derivatisations of the 3,3 diaryloxetane motif. Studies into the mechanism of the reaction using 1H NMR spectroscopy to observe oxetane ether intermediates are described. The same lithium catalyst is applied to the thiol alkylation of oxetanols with sulfides towards a wide range of novel 3-sulfanyloxetanes in excellent yields (up to 91%). The sulfide linker presents a versatile site for further derivatisation leading to novel oxetane containing structural classes and building blocks such as sulfoxides, sulfones, sodium sulfinate salts and sulfonyl fluorides. The reactivity of the oxetane-containing sulfinate salts and sulfonyl fluorides is described. In particular, oxetane-containing sulfonyl fluorides show exciting novel reactivity giving 3-aminooxetanes when reacted with a variety of amines instead of the expected sulfonamides. Studies into this unprecedented reactivity are described and compared to other alkyl sulfonyl fluorides. The final section of this thesis provides full experimental details and data for all compounds synthesised during the course of this research.
Blue straggler stars in dwarf spheroidal galaxies II: Sculptor and Fornax
Creators: name: Mapelli, M.
name: Ripamonti, E.
name: Battaglia, G.
name: Tolstoy, E.
name: Irwin, M. J.
name: Moore, B.
name: Sigurdsson, S.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The existence of blue straggler stars (BSSs) in dwarf spheroidal galaxies (dSphs) is still an open question. In fact, many BSS candidates have been observed in the Local Group dSphs, but it is unclear whether they are real BSSs or young stars. Shedding light on the nature of these BSS candidates is crucial, in order to understand the star formation history of dSphs. In this paper, we consider BSS candidates in Sculptor and Fornax. In Fornax there are strong hints that the BSS population is contaminated by young stars, whereas in Sculptor there is no clear evidence of recent star formation. We derive the radial and luminosity distribution of BSS candidates from wide field imaging data extending beyond the nominal tidal radius of these galaxies. The observations are compared with the radial distribution of BSSs expected from dynamical simulations. In Sculptor the radial distribution of BSS candidates is consistent with that of red horizontal branch (RHB) stars and is in agreement with theoretical expectations for BSSs generated via mass transfer in binaries. On the contrary, in Fornax the radial distribution of BSS candidates is more concentrated than that of all the considered stellar populations. This result supports the hypothesis that most of BSS candidates in Fornax are young stars and is consistent with previous studies.
description: 14 pages, 10 figures, accepted for publication in MNRAS
The effects of stellar gravity darkening on high-resolution transmission spectra
Creators: name: Cauley, P. Wilson
name: Ahlers, John P.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: High-resolution transmission spectroscopy is a powerful method for probing the extended atmospheres of short-period exoplanets. With the advancement of ultra-stable echelle spectrographs and the advent of 30-meter class telescopes on the horizon, even minor observational and physical effects will become important when modeling atmospheric absorption of atomic species. In this work we demonstrate how the non-uniform temperature across the surface of a fast rotating star, i.e., gravity darkening, can affect the observed transmission spectrum in a handful of atomic transitions commonly observed in short-period exoplanet atmospheres. We simulate transits of the ultra-hot Jupiters KELT-9 b and HAT-P-70 b but our results are applicable to all short-period gas giants transiting rapidly rotating stars. In general, we find that gravity darkening has a small effect on the average transmission spectrum but can change the shape of the absorption light curve, similar to the effect observed in broadband photometric transits. While the magnitude of gravity darkening effects are on the same order as the noise in transmission spectra observed with 10-meter class telescopes, future high-quality spectroscopic light curves for individual atomic absorption lines collected with 30-meter class telescopes will need to account for this effect.
description: 10 pages, 6 figures. Accepted to AAS Journals on 12/29/2021
Modelling of poliovirus transmission in Pakistan and Afghanistan to identify optimal vaccination strategies for eradication
Creators: name: Molodecky, Natalia A.
Publisher: name: Imperial College London
Year: 2017

description: The Global Polio Eradication Initiative (GPEI) is facing significant challenges in achieving its goal, including continued transmission of serotype-1 wild-type poliovirus (WPV1) in Pakistan and Afghani- stan and emerging outbreaks of serotype-2 vaccine-derived poliovirus (VDPV2) following global wi- thdrawal of serotype-2 oral poliovirus vaccine (OPV2). Here I address these challenges using statistical and mathematical analysis of global polio surveillance data. (1) I fit mixed-effects logistic regression models to the presence of WPV1 cases in districts of Pakistan and Afghanistan between 2010-2016. To accurately capture the force of infection between districts, 6 models of population movement were compared. The best-fitting model was used to produce forecasts of poliomyelitis incidence. The risk of polio cases was predicted to reduce in 2017. (2) I developed a stochastic mathematical model and fitted it to incidence of WPV1 in Pakistan and Afghanistan for 2010-2016. The developed model reliably captured WPV1 transmission dynamics and identified substantial between-district transmission and seasonality. (3) In 2015, I estimated population immunity against serotype-2 poliomyelitis in Pakistan and forecasted immunity for the time of planned OPV2 withdrawal using a cohort model. Immunity was forecasted to improve in April 2016. These analyses informed the endorsement of OPV2 withdrawal. (4) I developed a transmission model and fitted it to VDPV2 cases in Pakistan and Afghanistan for 2010-2016. Using the model, I determined optimal vaccination responses to VDPV2 outbreaks following OPV2 withdrawal. A greater spatial scale of response is required with increasing time since withdrawal and decreasing mucosal immunity. Incorporating inactivated poliovirus vaccine (IPV) into the response increases the probability of stopping transmission by minimizing risk of spread of reverted vaccine virus. In summary, these analyses have been used by the GPEI to adapt and develop their immediate and longer term strategy as evidenced in publications from the Strategic Advisory Group of Experts on Immunization [1, 2].
title: Proteolytic Enzymes of Lactic Streptococci and Their Use in Improving Body and Texture of Direct Acid Cottage Cheese
Creators: name: Vahora, Gulamnabi Y.
Publisher: name: Utah State University
Year: 1973

description: Proteolytic activity of Streptococcus cremoris HP, P2 and AM2; Streptococcus lactis-C2, ML8 and a commercial mixed culture was determined in skimmilk and whey by measuring the increase in Absorbency at 274.5 nm of a pH 4.6 soluble filtrate, following incubation in a 2.5% casein solution. Proteolytic activity, rate of acid production and growth rate decreased in order of C2, HP, mixed culture, AM2, ML8 and P2 at a regulated pH (6.1 - 6.2) and 32 C. Maximum proteolytic activity for all cultures was found during the stationary phase of growth. Extracellular protease activity was purified l000 fold from S. lactis-C2. Enzyme activity was stable at 80 C for 20 min and lost 41% of its activity after 80 min. A linear increase in activity was observed between 25 and 50 C after 5 hr incubation at pH 6.2.
Partial culturing of skimmilk, and incubation of a freeze-dried crude enzyme preparation in skimmilk prior to acidification was used for Cottage cheese ix making. Partial culturing or incubation of freeze-dried crude enzyme preparation in skimmilk prior to manufacture of direct acid Cottage cheese, increased the moisture and firmness of the finished curd, and significantly improved the body and texture of the creamed product. Partial culturing of skimmilk prior to acidification was also successfully used for the continuous process where good Cottage cheese curd was also obtained.
Agriculture and capacity building towards sustainable development in the Maldives
Creators: name: Van Driessche, Paul
Publisher: name: Imperial College London
Year: 2018

description: ABSTRACT The building of agricultural capacity through sustainable means is widely noted within the relevant literature relating to developing countries. Less so, is its coverage in the literature relating to small island developing states, specifically the Republic of Maldives. In addressing this lack of knowledge, this research seeks to provide an answer to the main research question: How can farmers in the Maldives build agricultural capacity through sustainable means? In answering this question, this research employs a vigorous, robust, and original methodology comprising a multisite case study with a phenomenological line of inquiry. This inquiry undertakes interviews, discussions, and journal observations with farmers, government experts, and associated community members in order to investigate the sociocultural, economic, and environmental context of the farmers’ agricultural experiences, and as importantly, what meanings the farmers derived from these experiences. This research noted that despite the agricultural interventions by the Maldivian Ministry of Fisheries and Agriculture (MoFA), the key provider of agricultural assistance to farmers, their attempts to build sustainable agricultural capacity often resulted in unanticipated and disappointing intervention outcomes for farmers. The findings of this research revealed that intervention slippages occurred where there was insufficient traction between MoFA, its donor partners, and the intended beneficiary farmers. These slippages were invariably characterised by dysfunctional projects and disinterested participants. As an agriculturalist based in the Maldives, I had observed such phenomena first hand, but the question remained “Why”? Analysis of the findings and relevant literature established where the intervention deficits resided, how they came about, and how best they could be addressed. This analysis was presented as a six-point farming framework that noted institutional interventions should be recalibrated with greater emphasis on the following: the sociocultural island context in which agriculture is undertaken; the preference for individualistic farming activity; the capture and promotion of entrepreneurialism and profitability in agriculture; the inclusion of migrant agricultural labour as a valued resource; knowledge transfer to farmers, institutions, and youth; and, the production and marketing connectivity between farmers and factor and producer markets. The research concluded that the opportunity for building sustainable capacity in agricultural practices resided within this framework.
title: Phosphate Requirements for a Whey-Based Lactic Bacteriophage Resistant Medium Under pH Control
Creators: name: Ausavanodom, Napasri
Publisher: name: Utah State University
Year: 1973

description: Five strains of lactic cultures and their homologous bacteriophage races were examined for response in a whey-based medium under pH control and fortified with zero to two percent levels of added orthophosphates. One percent each of culture and phage was inoculated into each medium, which was incubated at 25 C and continuously neutralized at pH 6.3 with 20 percent NH4OH. Growth response in media was compared against growth in non fat dry milk and a commercial phage inhibitory medium (Marstar).
The whey-based medium which had been frozen and thawed provided more effective growth response and greater phage protection than freshly prepared whey-based medium. Strain #3 grew optimally and was protected against phage inhibition with an added phosphate concentration of 0.5 percent whereas 0.7 percent was the required concentration in fresh whey-based medium.
One strain grew optimally and was protected against inhibition in only 0.5 percent added phosphate in the fresh whey-based medium. Two strains required 0.7 to 0.75 percent and two required 1 percent. All five produced acid more rapidly in whey-based medium than in the milk or phage inhibitory medium controls. Phage inhibitory medium which was stored for four years at 25 C supported culture growth as effectively as two month old medium.
Differential habitat use by a local population of the velvet-furred rat, Rattus lutreolus velutinus (Thomas 1882), in wet sclerophyll forest, SE Tasmania
Creators: name: Monamy, V
Publisher: name: University Of Tasmania
Year: 2023

description: This study investigates a reported decline in the proportion of male Rattus lutreolus velutinus in a trappable population during winter. A four hectare trapping grid was maintained between March 1989 and June 1990 in wet sclerophyll forest which had been burned by wildfire in 1967. The forest community displayed both structural and floristic heterogeneity. Four habitat groups were defined and capture data from 17 four-weekly trapping sessions are compared within these groups. R. l. velutinus exhibit a clear preference for areas of densest cover to one metre height and an avoidance of areas with little or no ground cover. During winter, areas of densest cover are utilized almost exclusively by females; males occupy areas with less cover at lower densities. During the breeding season, females continue to be captured in areas of densest ground cover. These areas are visited by numerous males in reproductive condition. An ecophysiological assessment of individuals in the trappable population was undertaken using routine blood sampling and the influence of environmental and artificial stressors on some haematological and endocrinological parameters is examined. Significant differences are evident between sexes for some measured parameters but no important differences are evident between the physiological states of individuals captured in different habitat groups. The results of this study indicate that a local population of R. l. velutinus may use habitat differentially but that individuals captured in different habitat groups do not differ in their physiological profiles or their ability to cope with environmental stressors. The intersexual difference in habitat use is discussed in relation to social spacing, resource utilization and female choice.
Detailed analysis on the reflection component for the black hole candidate MAXI J1348-630
Creators: name: Jia, Nan
name: Zhao, Xueshan
name: Gou, Lijun
name: Garcia, Javier A.
name: Liao, Zhenxuan
name: Feng, Ye
name: Li, Yufeng
name: Wang, Yuan
name: Li, Huixian
name: Wu, Jianfeng
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The black hole candidate MAXI J1348-630 was discovered on January 26th, 2019, with the Gas Slit Camera (GSC) on-board \textit{MAXI}. We report a detailed spectral analysis of this source by using the archived data of \textit{NuSTAR}. A total of 9 observations covered the complete outburst evolution of MAXI J1348-630 from the hard state to the soft state and finally back to the hard state. Additionally, the intermediate state is found in the transition from the hard state to the soft state. We use the state-of-art reflection model \verb'relxill' family to fit all the 9 spectra, and the spectra from two focal plane module detectors of \textit{NuSTAR} are jointly fitted for each observation. In particular, we concentrate on the results of the black hole spin parameter and the inclination of the accretion disk. Based on the analysis of the inner radius of the accretion disk, we obtain the spin parameter $a_* =0.78_{-0.04}^{+0.04}$, and the inclination angle of the inner disk $i = 29.2_{-0.5}^{+0.3}$ degrees. Furthermore, we also find that when the black hole is in the hard state, the accretion disk would show a significant truncation. The high iron abundance and ionization of the accretion disk obtained in the fitting results can be possibly explained by the high density of the accretion disk.
description: 8 pages, 4 figures, Accepted for publication in MNRAS
Systems biology analysis of gene expression in cardiopoiesis
Creators: name: Leja, Tomasz
Publisher: name: Imperial College London
Year: 2017

description: Myocardial infarction causes an irreversible loss of cardiac cells, frequently resulting in heart failure. Cardiac cell therapies using embryonic or adult stem cells offer promise to restore heart function. However, the convolution of molecular cues that guide cell differentiation and cardiogenesis hinders the use of appropriate regenerative strategies. The application of high-throughput, genome-wide and single-cell profiling methods provides quantitative insight into the regulatory mechanisms of tissue development. Systems biology methods are consequently required to decipher the spatial and temporal complexity of those regulatory circuits. Here, a quantitative systems approach is utilised to unravel the intricate network of genetic cues involved in cardiopoiesis, both from embryonic and adult stem cells. A new computational platform is presented for graph theoretical analysis of complex gene networks. The implemented methods for network reconstruction and dynamic graph partitioning are collectively tailored to uncover regulatory interactions from transcriptomic data. The addition of an integrated web-based interface meets the analytical challenges in systems biology, by complementing the execution workflow with an interactive visual network analysis. A systems analysis of genome-wide temporal expression profiles from differentiating embryonic stem cells is demonstrated. Graph theoretical principles were applied to obtain a Sox17-gene regulatory network, and to elucidate the endoderm-derived cardiokine signalling. Sox17 was shown to be essential in regulating Mesp1 induction, and a Sox17-Hhex-Cer1 circuit was further identified in mediating cardiac mesoderm specification. A bioinformatic framework is proposed to decouple the transcriptional heterogeneity among adult progenitor cells. A single-cell study of endogenous Lin−/Sca1+ cardiac precursor cells revealed heterogeneous expression of cardiogenic transcription factors, namely Gata4/6, Tbx2/20 and Hand2. The presence of Pdgfrα defined a discrete cellular fraction enriched with cardiogenic genes, representing an attractive target for heart regenerative therapies. Keywords: Regenerative medicine, cardiogenesis, embryonic stem cells, cardiac progenitor cells, systems biology, graph theoretical analysis.