bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors Promoting and Impeding Diversification of Forestry Resource-based Livelihoods in the Leh Himalaya of Ladakh Union Territory, India
Authors: Khan F.A. Shah , Islam M.A. , Gatoo A.A. , Bhat G.M. , Parrey A.A. , Bakshi M.R. , Atta Ummar , Chandramolly
Published: September 2024

Livelihood diversification through strengthening forestry resource-based interventions is an effective strategy for poverty alleviation and socioeconomic upliftment for downtrodden people. The study investigated the promoting and impeding factors that are crucial for the diversification of forestry resource-based livelihoods in Leh Himalaya of Ladakh Union Territory. The study is based on personal interviews with the selected 185 respondents through a structured interview schedule and non-participant observations carried out in the 9 sample villages of 5 blocks using a multi-stage random sampling technique. Descriptive statistics, including frequency, percentage, average, and simple ranking technique, were used to analyze the data. The findings based on their weighted mean score (WMS) and percentage score (PS) revealed that among the factors promoting the diversification of forestry resource-based livelihoods, forest resource self-sufficiency (WMS-1.98, PS-12.28%) was perceived as the most effective, while utilization of free time (WMS-0.73, PS-4.53%) was considered the least effective. Conversely, the most effective impeding factor for the diversification of forestry resource-based livelihoods considered among the people was labor-intensive and less remunerative livelihoods (WMS-1.96, PS-11.80%), while lack of cold storage facilities (WMS-0.74, PS-4.46%) was opined as the least effective. The insights into the promoting and impeding factors for diversification of forestry-based livelihoods highlighted in the study will be the basis for the planning and implementation of forestry programmes for forestry resource production and livelihood diversification in the Leh district of Ladakh. To make forestry-based livelihoods sustainable and reduce vulnerability, the prominent promoting and impeding factors must be exploited efficiently.
Evaluation of Hepatoprotective Activity of Ethanolic Extract of the Seed of Flacourtia jangomas against \(ccl_4\) -Induced Liver Damage in Rat Model
Authors: Prottasha Mafruza Khanam , Haq Kashfa , Nafsan Md Navid Rahman , Shawon Somaya Jannat , Rahmat Sara
Published: September 2024

Background: Hepatotoxicity is a serious global concern caused by the increased use of non-pharmacological substances and drugs. There are numerous medications available to treat this condition, the most well-known of which being silymarin. Although few, silymarin has certain adverse effects, which is why many are looking for alternatives, and medicinal plants may be a viable option. According to studies, Flacourtia jangomas has the potential to scavenge free radicals among therapeutic plants. We carried out this research to determine the hepatoprotective effects of an ethanolic extract of Flacourtia jangomas seeds.
Methods: The experiment used 45 rats divided into 9 groups of five each. 25 of them developed hepatotoxicity as a result of regular CCl4 administration.  One of the groups was the disease control group, while the other four were given their respective treatments. The treatment groups received 300, 600, and 1200 mg/kg of Flacourtia jangomas seed extract, respectively. After 28 days of treatment, the rats were sacrificed and blood samples were obtained to assess several parameters.
Results: Based on the result of the tests, all of the abnormal levels of serum glutamate oxidoacetic transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), creatinine, urea, total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglyceride (TG) were restored to normal levels in a dose-dependent manner, but a high dose in the case of SGPT and creatinine, and a medium and high dose in the case of urea, HDL, LDL, and TG were required to significantly restore the abnormal level with 95% confidence intervals.
Discussion: This study provides evidence that Flacourtia jangomas seed extract has the ability to provide hepatoprotection by acting as a free radical scavenger, possibly due to the presence of components like flavonoids, phenolic acids, and tannins.
Conclusion: As the seed of Flacourtia jangomas has the potential to exhibit hepatoprotective activity, intensive research is needed to isolate the genuine therapeutic compounds utilizing hydrophilic and hydrophobic solvents and introduce novel compounds to the disease management system.
The Role of Shariah Economics in Realizing Sustainable Development Based on Green Economy
Authors: Pradana Erwin , Amalia Sisi
Published: September 2024

The Green Economy is an issue that has recently become a popular topic of discussion. This research aims to understand the role of Sharia economics in reducing carbon dioxide emissions and helping to achieve the Sustainable Development Goals (SDGs), particularly in the economic development pillar. The research variables are renewable energy sources, using samples of hydroelectricity and biofuel. The study examines how much these two variables influence the contribution of carbon dioxide emissions produced annually in Indonesia. A quantitative approach with descriptive explanation is the most suitable method for this research, supported by secondary data sources. Based on the t-statistic test, both hydroelectricity and biofuel variables do not have an impact on carbon dioxide emissions resulting from various activities. However, the F-test shows that both hydroelectricity and biofuel contribute to carbon dioxide emissions, although their contribution is only 1%.
Green Economy is an issue that has started to be widely discussed and continuously voiced in the recent period. This study aims to determine the role of Islamic economics in reducing carbon dioxide emissions and helping to realize the goals of the SDGs, especially in the pillar of economic development. The variables of this study are renewable energy using hydroelectricity and biofuel samples. From these two variables, it is seen how much influence they have on the contribution of carbon dioxide emissions produced annually in Indonesia. Quantitative with descriptive explanation is the most suitable approach used in this study supported by secondary data sources. Based on the t-statistic test, the two hydroelectricity and biofuel variables have no effect on carbon dioxide emissions produced due to various activities. However, from the F test carried out, it can be seen that the hydroelectricity and biofuel variables both have a contribution to carbon dioxide emissions even though their contribution is only 1%.
Impact of Entrepreneurship Skill Acquisition on Youth and Graduate Unemployment in Owo Local Government Area, Ondo State, Nigeria
Authors: O Ogunro Victor , G. Akeredolu Adebisi , E Adedowole Babatope
Published: September 2024

Skill acquisition is the art of knowledge to do something in order to earn a living and or to stay alive. The concern for better livelihood has always been the concern of past and present government of Nigeria, this was why several youth empowerment programmes like sure-p and N-power was initiated by the Government of Goodluck Ebele Jonathan and Muhammodu Buhari to occupy the youth in active and productive activities that will better their lives and enable them contribute importantly to the Country economy. However, these schemes are yet to achieve the purposes for which it was established for, the better or rather sure bet to achieving these set goals was the integration of entrepreneurship skill acquisition programmes to help eliminate poverty and improve standard of living for rural dwellers in the Country. Hence, this study was carried out to examine entrepreneurship skills acquisition and youth unemployment of selected communities in Owo local government area in Ondo state, Nigeria. a total of 110 samples size was adopted, while the Chi-square (x2) contained in the statistical package for social sciences version 26 (SPSS) was used to the test the formulated hypotheses for the study, the findings from the study discovered Entrepreneurial skill acquisition has been considered very important in this research as a necessary antidote to the evidence problem of youth and graduate unemployment in Owo local government of Ondo state and the study is of the opinion that the introduction of entrepreneurial skill acquisition programmes will help the youth more especially in job and employment generation, create further opportunities for the young people to develop their enterprising skills and make them to be job creators and not job seekers. Therefore, the study recommended the government should as a matter of its civic responsibility, provide soft loans, fertilizer subsidy and mechanized materials and machineries to farmers in the rural area, through the bank of industry to enable them improve from their traditional ways of farming into a more mechanized way.
A proposal on the study of solar‐terrestrial coupling processes with atmospheric radars and ground‐based observation network
Authors: Tsuda Toshitaka , Yamamoto Mamoru , Hashiguchi Hiroyuki , Shiokawa Kazuo , Ogawa Yasunobu , Nozawa Satonori , Miyaoka Hiroshi , Yoshikawa Akimasa
Published: July 2016

The solar energy can mainly be divided into two categories: the solar radiation and the solar wind. The former maximizes at the equator, generating various disturbances over a wide height range and causing vertical coupling processes of the atmosphere between the troposphere and middle and upper atmospheres by upward propagating atmospheric waves. The energy and material flows that occur in all height regions of the equatorial atmosphere are named as “Equatorial Fountain.” These processes from the bottom also cause various space weather effects, such as satellite communication and Global Navigation Satellite System positioning. While, the electromagnetic energy and high‐energy plasma particles in the solar wind converge into the polar region through geomagnetic fields. These energy/particle inflow results in auroral Joule heating and ion drag of the atmosphere particularly during geomagnetic storms and substorms. The ion outflow from the polar ionosphere controls ambient plasma constituents in the magnetosphere and may cause long‐term variation of the atmosphere. We propose to clarify these overall coupling processes in the solar‐terrestrial system from the bottom and from above through high‐resolution observations at key latitudes in the equator and in the polar region. We will establish a large radar with active phased array antenna, called the Equatorial Middle and Upper atmosphere radar, in west Sumatra, Indonesia. We will participate in construction of the EISCAT_3D radar in northern Scandinavia. These radars will enhance the existing international radar network. We will also develop a global observation network of compact radio and optical remote sensing equipment from the equator to polar region.
Rabbit M1 and M2 macrophages can be induced by human recombinant GM‐CSF and M‐CSF
Authors: Yamane Kazuyoshi , Leung Kai‐Poon
Published: July 2016

Macrophages can change their phenotype in response to environmental cues. Polarized macrophages are broadly classified into two groups: classical activated M1 and alternative activated M2. Characterization of human macrophages has been widely studied, but polarized macrophages in rabbits have not been characterized. We characterized rabbit macrophages that were polarized using human recombinant GM‐CSF and M‐CSF. GM‐CSF‐treated macrophages had higher mRNA expression of proinflammatory cytokines (M1 phenotype) than did the M‐CSF‐treated counterpart. By contrast, high levels of TGF‐β and IL‐10 expression (M2 phenotype) were found in M‐CSF‐treated macrophages. The present study may be useful to understand roles of polarized macrophages in rabbit disease models.
X‐Ray Microtomographic Characterization and Quantification of the Strain Rate Dependent Failure Mechanism in Cenosphere Epoxy Syntactic Foams
Authors: Huang Ruoxuan , Li Peifeng , Wang Zhiyong , Liu Tong
Published: July 2016

This work investigates the failure mechanism in cenosphere epoxy syntactic foams at the quasi‐static and dynamic strain rates. Split‐Hopkinson pressure bar experiments are controlled to stop dynamic deformation of the foams at various strain stages. The internal microstructure at each strain is characterized in the x‐ray microtomography and compared to the microstructure in the foams deformed quasi‐statically. The microscopic observations reveal that the failure process in syntactic foams at the low and high rates is dominated by the crushing of cenospheres and the cracking of the epoxy matrix. However, the mechanism of failure in the foam is significantly affected by the strain rate. Compared to quasi‐static compression, macro‐cracks form earlier in the matrix at dynamic rates and can propagate to split cenospheres. The volume of the damage as defined by the failure of both cenospheres and the matrix is calculated from the x‐ray microtomographic images. It is found that the damage can be quantitatively related to the strain and the strain rate using an empirical equation.
Stabilization for Switched LPV Systems with Markovian Jump Parameters and Its Application
Authors: Yang Dong , Zhao Jun
Published: July 2016

This paper is concerned with the stabilization problem for a class of switched linear parameter‐varying (LPV) systems with Markovian jump parameters whose transition rate is completely unknown, or only its estimated value is known. Firstly, a new criterion for testing the stochastic stability of such systems is established. Then, using the multiple parameter‐dependent Lyapunov function method, we design a parameter‐dependent state‐feedback controller for individual switched LPV subsystem to guarantee stochastic stability of the closed‐loop switched LPV systems with Markovian jump parameters under uncertain transition rates. Finally, as an application of the proposed design method, the stabilization problem of a turbofan‐engine which cannot be handled by the existing methods is investigated.
A Study on Cooperative Voltage and Frequency Control Method Using Distributed Generations Considering Large Penetration of Renewable Energy Sources
Authors: SHIOHARA YUSUKE , TSUJI TAKAO , OYAMA TSUTOMU , SHINJI TAKAO , TADOKORO MASAYUKI
Published: July 2016

In order to solve energy and environmental issues, the introduction of photovoltaics (PVs) has been progressed in recent years. Due to the uncertain PV output fluctuation depending on the weather conditions, the proper frequency management becomes an important issue when a large amount of PVs are included in power systems. On the other hand, since the voltage increase in the end of feeder lines can be caused by the reverse power flow in distribution systems with PVs, it is needed to enhance the voltage controllability. When gas engine generators are included in distribution systems, they can contribute to both frequency and voltage control issues. However, the coordination between those control purposes will be another problem because the frequency and voltage controls have interactions each other. Hence, in this paper, we developed a distributed frequency control method taking into account the voltage constraint in distribution systems.
Synthesis and Multi‐Oxo Anion‐Binding Properties of Oligopyrrolic Macrocycles Based on Naphthobipyrrole
Authors: Abebayehu Abeje , Dutta Ranjan , Kim Soo‐Jin , Lee Ji Hye , Hwang Hyonseok , Lee Chang‐Hee
Published: July 2016

Oligopyrrolic macrocycles based on the naphthobipyrrole scaffold have been synthesized and characterized. The compounds showed high affinities toward multi‐oxo anions such as dihydrogen phosphate and sulfate anions in acetonitrile. Theoretical calculations for the formation of host–anion complexation revealed that the receptors adopt bowl‐shaped, cone conformations with association constants of ca. 106 m–1 with dihydrogen phosphate anions.
Preclinical evaluation of near‐infrared (NIR) fluorescently labeled cetuximab as a potential tool for fluorescence‐guided surgery
Authors: Saccomano Mara , Dullin Christian , Alves Frauke , Napp Joanna
Published: July 2016

The high rate of recurrence in patients with pancreatic ductal adenocarcinoma (PDAC) could be reduced by supporting the surgeons in discriminating healthy from diseased tissues with intraoperative fluorescence‐guidance. Here, we studied the suitability of Cetuximab, a therapeutic monoclonal antibody targeting the human epidermal growth factor receptor (EGFR), near‐infrared (NIR) fluorescently labeled as a new tool for fluorescence‐guided surgery. Distribution and binding of systemically injected Cetuximab Alexa Fluor 647 conjugate (Cetux‐Alexa‐647) and the co‐injected control human IgG Alexa Fluor 750 conjugate (hIgG‐Alexa‐750) was studied over 48 h by NIR fluorescence imaging in mice bearing human orthotopic AsPC‐1 and MIA PaCa‐2 PDAC tumors. Cetux‐Alexa‐647, but not the control hIgG‐Alexa‐750 fluorescence, was specifically detected in vivo in both primary pancreatic tumors with maximum fluorescence intensities at 24 h, and in metastases of AsPC‐1 tumors as small as 1 mm. Lifetime analysis and NIR fluorescence microscopy of tumor sections confirmed the binding specificity of Cetux‐Alexa‐647 to PDAC cells. Comparable results were obtained with Cetuximab conjugated to Alexa Fluor 750 dye (Cetux‐Alexa‐750). Fluorescence‐guided dissection, performed 24 h after injection of Cetuximab conjugated to IRDye 800CW (Cetux‐800CW), enabled a real‐time delineation of AsPC‐1 tumor margins, and small metastases. Odyssey scans revealed that only the vital part of the tumor, but not the necrotic part was stained with Cetux‐800CW. NIR fluorescently labeled Cetuximab may be a promising tool that can be applied for fluorescence‐guided surgery to visualize tumor margins and metastatic sites in order to allow a precise surgical resection.
A Role for Focal Adhesion Kinase in the Stimulation of Glucose Transport in Cardiomyocytes
Authors: Viglino Christelle , Montessuit Christophe
Published: July 2016

Stimulation of glucose transport is markedly impaired in cardiomyocytes exposed to free fatty acids (FFA), despite relative preservation of canonical insulin‐ or metabolic stress signaling. We determined whether Focal Adhesion Kinase (FAK) activity is required for stimulation of glucose transport in cardiomyocytes, and whether FAK downregulation participates in FFA‐induced impairment of glucose transport stimulation. Glucose transport, measured in isolated cultured cardiomyocytes, was acutely stimulated either by insulin treatment, or by metabolic inhibition with oligomycin resulting in AMP‐activated kinase (AMPK) activation. FAK activity was inhibited pharmacologically by preincubation with PF‐573,228 (PF). FAK activity was assessed from its autophosphorylation on residue Y397, and from the phosphorylation of its target paxillin on Y118. Y397 FAK phosphorylation was reduced in cultured cardiomyocytes chronically exposed to FFA. Preincubation with PF prior to determination of glucose transport resulted in a significant reduction of oligomycin‐stimulated glucose transport, with a lesser reduction in insulin‐stimulated glucose transport. Insulin and AMPK signaling was unaffected by PF preincubation. siRNA‐mediated FAK knockdown also resulted in reduced oligomycin‐stimulated glucose transport. Chronic treatment of FFA‐exposed cardiomyocytes with phenylephrine or a phorbol ester restored FAK activity and improved glucose transport. In conclusion, stimulation of glucose transport in cardiomyocytes requires FAK activity prior to stimulation. The chronic reduction of FAK activity in cardiomyocytes exposed to FFA contributes to the loss of glucose transport responsiveness to insulin or metabolic inhibition. J. Cell. Biochem. 118: 670–677, 2017. © 2016 Wiley Periodicals, Inc.
Synthesis and quality control of [18F]T807 for tau PET imaging
Authors: Holt Daniel P. , Ravert Hayden T. , Dannals Robert F.
Published: July 2016

The detailed synthesis and quality control of [18F]T807, radiotracer for tau protein aggregate imaging, are described. The radiotracer synthesis was accomplished in an average of 48 min with an average specific activity at end‐of‐synthesis of over 4.4 TBq/µmole (120 Ci/µmole) and an average radiochemical yield of 32%. Compliance with all standard US Pharmacopeia Chapter <823> acceptance tests was observed.
From inbox to enroll: Email marketing tips
Authors: Talarico Donna
Published: July 2016

Working adults spend a lot of time in their inboxes. According to Pew Research, 92 percent of adults use email and, says McKinsey & Company, 13 of their working hours each week are devoted to checking mail.
Strain‐ and torsion‐induced resonance energy tuning of Raman scattering in single‐wall carbon nanotubes
Authors: Nikolić Božidar , Damnjanović Milan , Milošević Ivanka
Published: July 2016

Raman excitation profiles for homogeneously deformed single‐walled carbon nanotubes are calculated and systematically analyzed. A number of attractive and apparent effects significant in designing electromechanical devices are caused by torsion and uniaxial strain. The shift of radial breathing mode (RBM) phonon energies due to deformation is negligible. The linear dependence of electronic transition energy shift on deformation is confirmed and it is found that the slope of it is strongly related to the chiral angle of the tube. It is also shown that for some tubes the transition energy shift covers the entire visible‐light interval, making them perfectly tunable light absorbers. Two types of deformation are compared, a relaxed (slow) deformation and an adiabatic (fast) one. It is found that transition energies are more sensitive to adiabatic deformation, which can be useful for optomechanical device designing.

Raman excitation profile of a (9,9) nanotube under torsion.
Riding the Wave of Monodentate Ligand Revival: From the A/B Concept to Noncovalent Interactions
Authors: Pignataro Luca , Gennari Cesare
Published: July 2016

The rediscovery of chiral monodentate ligands made in the period 1999–2003 had important consequences in enantioselective transition‐metal catalysis, such as the introduction of the A/B concept (i.e., use of monodentate ligand mixtures) and, later, a renewed interest in supramolecular ligands capable of ligand–ligand and ligand–substrate interactions. This Personal Account summarizes the contributions made by our research group in this area in the period 2004–2015, which reflect the abovementioned developments. Within this area, we introduced some original concepts, such as 1) the use of chiral tropos ligand mixtures; 2) the development of new strategies to maximize heterocomplex formation from combinations of simple monodentate ligands; 3) the investigation of new ligand–ligand interactions to achieve selective heterocomplex formation; and 4) the development of highly efficient and synthetically accessible supramolecular ligands.

image
Number of lymph nodes dissected in colorectal cancer and probability of positive nodes, angiolymphatic/perineural invasion, and intracellular mucin in a referral service
Authors: Frasson Murilo Zomer , Kock Kaiser S. , Monteiro Letícia F. , Romagna Jonas V.
Published: July 2016

Among the malignancies, colorectal cancer ranks fourth in incidence in Brazil. The main prognostic measure is related to the amount of affected lymph nodes. Thus, many studies try to correlate the number of extracted lymph nodes, with the probability of obtaining positive nodes.

Study objectives Determine whether dissection ≥12 lymph nodes increases probability of finding neoplastic involvement in relation to resection of fewer. Assess the presence of angiolymphatic invasion; perineural and intracelluar mucin and correlate it with tumor differentiation and TNM classification. Correlate the average of positive nodes with angiolymphatic and perineural involvement.

Methods Pathological reports of patients operated for CRC from 1997 to 2013 were analyzed. A probability (p) less than 0.05 was considered to indicate statistical significance.

Results Median of lymph nodes sent to analysis was 12 nodes. Average number of lymph nodes affected was higher when a number ≥12 lymph nodes were dissected (p = 0.001) (Kruskal–Wallis). There was positive association between average of affected lymph nodes and presence of angiolymphatic (p < 0.0001) or perineural invasion (p = 0.024). Angiolymphatic and intracellular mucin are less present in well-differentiated adenocarcinomas. Perineural and angiolymphatic were more present in T4 stages.

Conclusions Dissection ≥12 lymph nodes increases chances of finding positive nodes. There is relation between angiolymphatic invasion; perineural and intracellular mucin and type of tumor differentiation, as well as TNM classification. Average number of lymph nodes affected was higher in presence of perineural or angiolymphatic invasion.
Volume/area scaling of glaciers and ice caps and their longitudinal profiles
Authors: FARAONI VALERIO
Published: July 2016

Empirical data on the volume/area scaling of glaciers and ice caps are compared with theoretical models of longitudinal glacier profiles. Ice caps are described well by theoretical solutions of the differential equations modeling longitudinal profiles, but glaciers for which the surface slope is approximated by the ice thickness divided by the length are not. A power-law profile recently derived analytically, reproduces exactly the thickness-length scaling, first predicted by scaling analysis for ice caps.
INTEGRATION AND CELL DECOMPOSITION IN P-MINIMAL STRUCTURES
Authors: KOVACSICS PABLO CUBIDES , LEENKNEGT EVA
Published: July 2016

We show that the class of ${\cal L}$-constructible functions is closed under integration for any P-minimal expansion of a p-adic field $\left( {K,{\cal L}} \right)$. This generalizes results previously known for semi-algebraic and subanalytic structures. As part of the proof, we obtain a weak version of cell decomposition and function preparation for P-minimal structures, a result which is independent of the existence of Skolem functions. A direct corollary is that Denef’s results on the rationality of Poincaré series hold in any P-minimal expansion of a p-adic field $\left( {K,{\cal L}} \right)$.
The diffusion of Radon shape
Authors: Panaretos Victor M.
Published: July 2016

In 1977 D. G. Kendall considered diffusions of shape induced by independent Brownian motions in Euclidean space. In this paper, we consider a different class of diffusions of shape, induced by the projections of a randomly rotating, labelled ensemble. In particular, we study diffusions of shapes induced by projections of planar triangular configurations of labelled points onto a fixed straight line. That is, we consider the process in Σ13(the shape space of triads in ℝ) that results from extracting the ‘shape information’ from the projection of a given labelled planar triangle as this evolves under the action of Brownian motion in SO(2). We term the thus-defined diffusionsRadon diffusionsand derive explicit stochastic differential equations and stationary distributions. The latter belong to the family of angular central Gaussian distributions. In addition, we discuss how these Radon diffusions and their limiting distributions are related to the shape of the initial triangle, and explore whether the relationship is bijective. The triangular case is then used as a basis for the study of processes in Σ1karising from projections of an arbitrary number,k, of labelled points on the plane. Finally, we discuss the problem of Radon diffusions in the general shape space Σnk.
Loss asymptotics in large buffers fed by heterogeneous long-tailed sources
Authors: Likhanov Nikolay , Mazumdar Ravi R.
Published: July 2016

This paper presents the large-buffer asymptotics for a multiplexer which serves N types of heterogeneous sessions which have long-tailed session lengths. Specifically, the model considered is that sessions of type i ∈ {1,…,N} arrive as a Poisson process with rate λi. Each type of session (independently) remains active for a random duration, say τi, where P(τi > x) ~ αix-(1 + βi) for positive numbers αi and βi. While active, a session transmits at a rate ri. Under the assumption that the average load ρ = ∑Ni=1riλiE[τi] < C, where C denotes the server capacity, we show that both the tail distribution of the stationary buffer content and the loss asymptotics in finite buffers of size z behave approximately as z-κJ0, where κJ0 depends not only on the βi but also on the transmission rates ri; it is the ratio of βi to ri which determines κJ0. When specialized to the homogeneous case, i.e., when ri=r and βi = β for all i, the result coincides with results reported in the literature which have been shown under more restrictive hypotheses. Finally, it is a simple observation that light-tailed sessions only have the effect of reducing the available capacity for long-tailed sessions, but do not contribute otherwise to the definition of κJ0.
Densities of mixed volumes for Boolean models
Authors: Weil Wolfgang
Published: July 2016

In generalization of the well-known formulae for quermass densities of stationary and isotropic Boolean models, we prove corresponding results for densities of mixed volumes in the stationary situation and show how they can be used to determine the intensity of non-isotropic Boolean models Z in d-dimensional space for d = 2, 3, 4. We then consider non-stationary Boolean models and extend results of Fallert on quermass densities to densities of mixed volumes. In particular, we present explicit formulae for a planar inhomogeneous Boolean model with circular grains.
Disasters in a Markovian inventory system for perishable items
Authors: Perry David , Stadje Wolfgang
Published: July 2016

We study a Markovian model for a perishable inventory system with random input and an external source of obsolescence: at Poisson random times the whole current content of the system is spoilt and must be scrapped. The system can be described by its virtual death time process. We derive its stationary distribution in closed form and find an explicit formula for the Laplace transform of the cycle length, defined as the time between two consecutive item arrivals in an empty system. The results are used to compute several cost functionals. We also derive these functionals under the corresponding heavy traffic approximation, which is modeled using a Brownian motion in [0,1] reflected at 0 and 1 and restarted at 1 at the Poisson disaster times.
Optimal repair/replacement policy for a general repair model
Authors: Jiang Xiaoyue , Makis Viliam , Jardine Andrew K. S.
Published: July 2016

In this paper, we study a maintenance model with general repair and two types of replacement: failure and preventive replacement. When the system fails a decision is made whether to replace or repair it. The repair degree that affects the virtual age of the system is assumed to be a random function of the repair-cost and the virtual age at failure time. The system can be preventively replaced at any time before failure. The objective is to find the repair/replacement policy minimizing the long-run expected average cost per unit time. It is shown that a generalized repair-cost-limit policy is optimal and the preventive replacement time depends on the virtual age of the system and on the length of the operating time since the last repair. Computational procedures for finding the optimal repair-cost limit and the optimal average cost are developed. This model includes many well-known models as special cases and the approach provides a unified treatment of a wide class of maintenance models.
On a coverage process ranging from the Boolean model to the Poisson–Voronoi tessellation with applications to wireless communications
Authors: Baccelli François , Błaszczyszyn Bartłomiej
Published: July 2016

We define and analyse a random coverage process of the d-dimensional Euclidean space which allows us to describe a continuous spectrum that ranges from the Boolean model to the Poisson–Voronoi tessellation to the Johnson–Mehl model. As for the Boolean model, the minimal stochastic setting consists of a Poisson point process on this Euclidean space and a sequence of real valued random variables considered as marks of this point process. In this coverage process, the cell attached to a point is defined as the region of the space where the effect of the mark of this point exceeds an affine function of the cumulative effect of all marks. This cumulative effect is defined as the shot-noise process associated with the marked point process. In addition to analysing and visualizing this spectrum, we study various basic properties of the coverage process such as the probability that a point or a pair of points be covered by a typical cell. We also determine the distribution of the number of cells which cover a given point, and show how to provide deterministic bounds on this number. Finally, we also analyse convergence properties of the coverage process using the framework of closed sets, and its differentiability properties using perturbation analysis. Our results require a pathwise continuity property for the shot-noise process for which we provide sufficient conditions. The model in question stems from wireless communications where several antennas share the same (or different but interfering) channel(s). In this case, the area where the signal of a given antenna can be received is the area where the signal to interference ratio is large enough. We describe this class of problems in detail in the paper. The results obtained allow us to compute quantities of practical interest within this setting: for instance the outage probability is obtained as the complement of the volume fraction; the law of the number of cells covering a point allows us to characterize handover strategies, and so on.
Computational analysis of single-server bulk-service queues, M/GY
/ 1
Authors: Brière G. , Chaudhry M. L.
Published: July 2016

Algorithms are proposed for the numerical inversion of the analytical solutions obtained through classical transform methods. We compute steady-state probabilities and moments of the number of customers in the system (or in the queue) at three different epochs—postdeparture, random, and prearrival—for models of the type M/GY/1, where the capacity of the single server is a random variable. This implies first finding roots of the characteristic equation, which is detailed in an appendix for a general service time distribution. Numerical results, given a service time distribution, are illustrated through graphs and tables for cases covered in this study: deterministic, Erlang, hyperexponential, and uniform distributions. In all cases, the proposed method is computationally efficient and accurate, even for high values of the queueing parameters. The procedure is adaptable to other models in queueing theory (especially bulk queues), to problems in inventory control, transportation, flexible manufacturing process, etc. Exact results that can be obtained from the algorithms presented here will be found useful to test inequalities, bounds, or approximations.
New results for the Jackson network
Authors: Massey William A.
Published: July 2016

Using operator methods, we prove a general decomposition theorem for Jackson networks. For its transient joint queue-length distribution, we can stochastically bound it above by a network that decouples into smaller independent Jackson networks.
Two competing queues with linear costs: the μc-rule is often optimal
Authors: Baras J. S. , Dorsey A. J. , Makowski A. M.
Published: July 2016

A state-space model is presented for a queueing system where two classes of customer compete in discrete-time for the service attention of a single server with infinite buffer capacity. The arrivals are modelled by an independent identically distributed random sequence of a general type while the service completions are generated by independent Bernoulli streams; the allocation of service attention is governed by feedback policies which are based on past decisions and buffer content histories. The cost of operation per unit time is a linear function of the queue sizes. Under the model assumptions, a fixed prioritization scheme, known as the μc -rule, is shown to be optimal when the expected long-run average criterion and the expected discounted criterion, over both finite and infinite horizons, are used. This static prioritization of the two classes of customers is done solely on the basis of service and cost parameters. The analysis is based on the dynamic programming methodology for Markov decision processes and takes advantage of the sample-path properties of the adopted state-space model.
Arrival control of load-sharing queueing systems
Authors: Jo Kyung Y. , Greenland Arnold
Published: July 2016

We consider a system of three queues in which arriving customers are assigned to other queues if rejected from entry to one queue; and thus the work load of each queue is shared. The objective function considered is a combination of holding costs, routing costs, and customer service rewards. We first establish the characteristics of optimal control policies via a Markov decision process formulation. Next, the decomposed problems with partial information for each server are considered and the results compared with the original problem are shown. Appropriate combinations of optimal solutions for the decomposed problems are then used either in approximating the centralized optimal policy or in determining a good starting policy for successive approximation of the multidimensional Markov decision process. Numerical results of specific models are also presented.
Discrete-time approximationsfor continuous-time Markoviancontrol systems
Authors: Hordijk A. , Van Der Duyn Schouten F. A.
Published: July 2016

The method of discrete-time approximation is widespread in control and decision theory. However, little attention has been paid to the conditions on parameters and control under which the discrete-time systems come close to the continuous-time system.
Solving the Hamilton-Jacobi-Bellman equation of stochastic control by a semigroup perturbation method
Authors: Vermes Domokos
Published: July 2016

We consider the optimal control of deterministic processes with countably many (non-accumulating) random iumps. A necessary and sufficient optimality condition can be given in the form of a Hamilton-jacobi-Bellman equation which is a functionaldifferential equation with boundary conditions in the case considered. Its solution, the value function, is continuously differentiable along the deterministic trajectories if. the random jumps only are controllable and it can be represented as a supremum of smooth subsolutions in the general case, i.e. when both the deterministic motion and the random jumps are controlled (cf. the survey by M. H. A. Davis (p.14)).
Non-linear compartmental models
Authors: Faddy M. J.
Published: July 2016

The linear compartmental model arises when ‘particles’ move independently between (or out of) a system of compartments in a stochastically similar way. With a given ‘initial’ particle count, the subsequent compartmental particle counts follow multinomial probability distributions (Faddy (1976)) for Markov or semi-Markov movement processes. One immediate consequence of this is that the variance of the compartmental particle count is always less than the mean, with the result that the coefficient of variation is very small for large mean counts. In applications (e.g, Faddy, Jones and Edwards (1976)) this underestimation of the variation can be a shortcoming of a compartmental analysis. Clustering, introduced by Matis and Wehrly (1981), where ‘clusters’ of particles may move together, is a way in which increased variability may be attained. Increased variability in general will result from relaxing the main assumption that gives rise to a linear model: independent behaviour of the particles. Such nonlinear compartmental models can be generally difficult to handle; in this paper some particular cases are discussed and illustrated with reference to one- and twocompartment systems.
Mark-recapture models
Authors: Macdonald P. D. M.
Published: July 2016

The interpretation of mark-recapture data depends on a probabilistic model for the biological system. The assumptions of the general model must be verified against what is known about the particular system. This talk considers the application of markrecapture methods to the estimation of salmon smolt migrations from Babine Lake, British Columbia.
The early growth of cancer
Authors: King James H. , Chover Joshua
Published: July 2016

The determination of the kinetics of early cancer growth has received considerable attention from cancer researchers interested in reducing the time required to assess carcinogenic risk. The three main difficulties in this study are: (1) tumors can only be identified after the animal has been sacrificed, (2) each animal exhibits considerable variability in tumor sizes and (3) tumors can only be identified once they have grown above a threshold size. Thus, the only data available to the researcher summarizes the sizes of observable tumors at the time of sacrifice. In this paper, we give techniques to help the researcher decide the type of tumor growth (e.g., exponential, logistic, Gompertz), the time at which the cancerous growth began, as well as the principal source of variability in tumor sizes (either the time of the initial growth, or the rate of growth). Additional techniques can be used to decide if the rate of growth increases with time (a consequence of the increased malignancy of the tumor) or decreases with time (due to the lack of oxygenation at the core of a large tumor). These techniques are applied to data on microscopic liver tumors (often called foci) from the lab of Dr Stanley Goldfarb (Department of Pathology, University of Wisconsin-Madison).
A time-dependent stopping problem with application to live organ transplantation
Authors: David Israel , Yechiali Uri
Published: July 2016

Offers become available from time to time. The offers constitute a sequence of i.i.d. positive random variables. Upon arrival of an offer a decision is taken whether to accept it or not. When an offer is accepted the process terminates. Otherwise, the offer is lost and the process continues until the next arrival or until a moment where it terminates by itself. The probability of self-termination depends on the age of the underlying process.
Plasmid loss: the role of conjugation and copy number
Authors: Esty Warren W.
Published: July 2016

Plasmids are subcellular particles somewhat similar to, but sirnpler than, viruses. A small part of the host cell's genome, they multiply independently within host cells and are apparently inherited in a random manner. They code important genetic traits not normally encoded and are responsible for several plant and animal diseases; they can also confer the ability to resist a wide variety of toxic agents.
A compartmental model in a random environment
Authors: O'Cinneide Colm Art
Published: July 2016

The M/M/∞ queue can be considered as a compartmental system which may be modified by allowing its arrival and service rates to depend on an exogenous ‘environment process’. The states of the environment process are known as environments. We present some examples of this, chosen for their analytic or algorithmic tractability. We discuss (i) models with arrivals in only one environment, (ii) models with service in only one environment, (iii) reversible models and (iv) a model in which the environment process is also a queue.
Conservative mutations in non-ambiguous genetic codes
Authors: Kocherlakota R. R.
Published: July 2016

Conservative mutations (those which do not change the amino acid coded for a codon) are discussed. In particular, formulas are given for the computation of the probability that a mutation is conservative and the expected value of this probability if the genetic code were randomly permuted, assuming wobble and non-wobble conditions.
On Statistical Analysis of Sequence Symmetries in DNA/RNA
Authors: Shukla Rakesh K. , Srivastava R. C.
Published: July 2016

A predominance of certain ‘sequence systemmetries’ in DNA/RNA has led to various conjectures about the possible structural/functional role these symmetries might play in nucleic acid sequences. De Wachter employed a binomial probability model to compare the observed number of ‘direct repeats’ with those expected in a random sequence. Counting of direct repeats essentially leads to a sequence of m-dependent trials. We develop a stochastic model for studying various types of symmetries. Expressions for means and variances of the statistics employed are derived. The asymptotic distributions are obtained using the central limit theorem for m-dependent random variables. It is proposed that each sequence pattern be examined separately for its chance occurrence as opposed to what de Wachter suggests, i.e., clumping of all patterns together. It is also shown how our model can be used to detect various gene-amplification events, if any, in nucleic acid sequences. Finally, for certain types of patterns, it is indicated how the theory of recurrent events can be used to get a better handle on the analysis of direct repeats.
On a random variable related to a system of convex bodies in the Euclidean space E
n
Authors: Stoka Marius
Published: July 2016

Let us consider, in the Euclidean space E

n
, a fixed n-dimensional convex body K
0 of volume V
0 and a system K
1,…,K

m
of m
n-dimensional convex bodies, congruent to a convex set K. Assume that the sets K

i
(i = 1,…,m) have random positions, being stochastically independent and uniformly distributed on a limited domain of E

n
and denote by
V

m
the volume of the convex body
K

m
= K
0 ∩ (K
1 ∩ … ∩ K

m
). The aim of this paper is the evaluation of the second moment of the random variable
V

m
.
A test for discrete Boolean models
Authors: Montes Francisco , Plaza Mario
Published: July 2016

For a discrete random set defined on a bounded subset B ⊂ ℤ2, the paper proposes a test for checking the Boolean hypothesis against its natural alternatives: models whose process of germs show a major tendency versus regularity or aggregation represented by a hardcore process or Poisson's cluster process. The test is based on the contents, T, of the difference XD - X, where X is the original model and XD = X ⊕ C is its dilation by the structurant element C.
The minimisation of helicopter vibration through blade design and active control
Authors: King S. P.
Published: July 2016

The high level of vibration experienced on the helicopter has been an unfortunate feature of the vehicle throughout its existence, and considerable efforts have been expended over many years in attempts to reduce vibration to levels typical of other forms of transport. Much has been achieved, but as the forward speed increases some components of rotor generated vibration increase very rapidly and consequently, at the increased cruise speed of modern helicopters, vibration can still be high. Also, the requirements have become more stringent, due partly to what the passengers or crew are prepared to tolerate, and partly to the complexity of the tasks required of the crews, especially on military machines.
Flight simulation in the Royal Air Force in the Second World War
Authors: Rolfe J. M. , Bolton M.
Published: July 2016

The approach taken by this examination of flight simulation in the RAF in the Second World War reflects the fact that one author is an engineer and the other a psychologist. As a consequence the paper not only attempts to examine the technology that was established to create the training devices but also something of the personalities who created the simulators and the applications to which they were applied.

In the space available it will only be possible to skim the surface of a topic which has been relatively undisturbed for some thirty years. The authors hope is that the paper will stimulate interest and admiration for the dedicated and ingenious innovators who set out to create the devices which enabled the Royal Air Force to learn new skills safely and apply them effectively.