18,020 research outputs found
Effects of temperature and relative humidity on the egg laying pattern of Rhipicephalus sanguineus (Koch, 1844) infesting sheep in semi-arid region of Nigeria
The ovipositional pattern of fully engorged adult female Rhipicephalus sanguineus infesting sheep was studied under belljar conditions of mean ± SD (range) temperature of 25.4±2.16 (23 -29oC) and relative humidity 90% and ambient conditions of 26.4±2.4 (23.6-31.6oC) and relative humidity 63.0±3.93 (51.3-72%). The pre-oviposition days under belljar conditions (11.1±9.15) was significantly shorter (p<0.05) than ambient conditions (14.5±14.9 days), each having post oviposition weights of 0.11±0.04 grams and 0.17±0.012 grams respectively, indicating a decrease in weight of the ticks after oviposition. The mean ±SD oviposition period (days) was shorter (p>0.05) under belljar (22.3±9.69) than ambient (23.7±10.7) conditions with the total mean ± SD number of eggs laid under each condition as 1021.9±1082.4 and 1096.9±1173.0 respectively (p<0.05). The peak oviposition period was day 13 for belljar and day 16 for ambient conditions each with mean ± SD egg lay of 2100 and 2260, and peak total o f 3936 and 3610 eggs respectively. It is concluded that the ovipositional behaviour of Rh. sanguinues could be influenced by temperature and humidity changes
Heat flow method to Lichnerowicz type equation on closed manifolds
In this paper, we establish existence results for positive solutions to the
Lichnerowicz equation of the following type in closed manifolds -\Delta
u=A(x)u^{-p}-B(x)u^{q},\quad in\quad M, where , and ,
are given smooth functions. Our analysis is based on the global
existence of positive solutions to the following heat equation {ll} u_t-\Delta
u=A(x)u^{-p}-B(x)u^{q},\quad in\quad M\times\mathbb{R}^{+}, u(x,0)=u_0,\quad
in\quad M with the positive smooth initial data .Comment: 10 page
A catalog of Kazarian galaxies
The entire Kazarian galaxies (KG) catalog is presented which combines
extensive new measurements of their optical parameters with a literature and
database search. The measurements were made using images extracted from the
STScI Digitized Sky Survey (DSS) of Jpg(blue), Fpg(red) and Ipg(NIR) band
photographic sky survey plates obtained by the Palomar and UK Schmidt
telescopes. We provide accurate coordinates, morphological type, spectral and
activity classes, blue apparent diameters, axial ratios, position angles, red,
blue and NIR apparent magnitudes, as well as counts of neighboring objects in a
circle of radius 50 kpc from centers of KG. Special attention was paid to the
individual descriptions of the galaxies in the original Kazarian lists, which
clarified many cases of misidentifications of the objects, particularly among
interacting systems. The total number of individual Kazarian objects in the
database is now 706. We also include the redshifts which are now available for
404 galaxies and the 2MASS infrared magnitudes for 598 KG. The database also
includes extensive notes, which summarize information about the membership of
KG in different systems of galaxies, and about revised activity classes and
redshifts. An atlas of several interesting subclasses of KG is also presented.Comment: 15 pages, 5 figures, 1 table, Accepted in Astrophysics, Vol. 53, No.
1, 2010 (English translation of Astrofizika
Anomalous Density-of-States Fluctuations in Two-Dimensional Clean Metals
It is shown that density-of-states fluctuations, which can be interpreted as
the order-parameter susceptibility \chi_OP in a Fermi liquid, are anomalously
strong as a result of the existence of Goldstone modes and associated strong
fluctuations. In a 2-d system with a long-range Coulomb interaction, a suitably
defined \chi_OP diverges as 1/T^2 as a function of temperature in the limit of
small wavenumber and frequency. In contrast, standard statistics suggest
\chi_OP = O(T), a discrepancy of three powers of T. The reasons behind this
surprising prediction, as well as ways to observe it, are discussed.Comment: 4 pp, revised version contains a substantially expanded derivatio
Does ozone have any effect on daily hospital admissions for circulatory diseases?
published_or_final_versio
A new instrument for time-resolved measurement of HO2 radicals
OH and HO2 radicals are closely coupled in the atmospheric oxidation and combustion of volatile organic compounds (VOCs). Simultaneous measurement of HO2 yields and OH kinetics can provide the ability to assign site-specific rate coefficients that are important for understanding the oxidation mechanisms of VOCs. By coupling a fluorescence assay by gaseous expansion (FAGE) laser-induced fluorescence (LIF) detection system for OH and HO2 with a high-pressure laser flash photolysis system, it is possible to accurately measure OH pseudo-1st-order loss processes up to ∼100 000 s−1 and to determine HO2 yields via time-resolved measurements. This time resolution allows discrimination between primary HO2 from the target reaction and secondary production from side reactions. The apparatus was characterized by measuring yields from the reactions of OH with H2O2 (1:1 link between OH and HO2), with C2H4∕O2 (where secondary chemistry can generate HO2), with C2H6∕O2 (where there should be zero HO2 yield), and with CH3OH∕O2 (where there is a well-defined HO2 yield).
As an application of the new instrument, the reaction of OH with n-butanol has been studied at 293 and 616 K. The bimolecular rate coefficient at 293 K, (9.24±0.21)×10−12 cm3 molec.−1 s−1, is in good agreement with recent literature, verifying that this instrument can measure accurate OH kinetics. At 616 K the regeneration of OH in the absence of O2, from the decomposition of the β-hydroxy radical, was observed, which allowed the determination of the fraction of OH reacting at the β site (0.23±0.04). Direct observation of the HO2 product in the presence of oxygen has allowed the assignment of the α-branching fractions (0.57±0.06) at 293 K and (0.54±0.04) at 616 K, again in good agreement with recent literature; branching ratios are key to modelling the ignition delay times of this potential “drop-in” biofuel
Recommended from our members
Coupling between gamma-band power and cerebral blood volume during recurrent acute neocortical seizures
Characterization of neural and hemodynamic biomarkers of epileptic activity that can be measured using non-invasive techniques is fundamental to the accurate identification of the epileptogenic zone (EZ) in the clinical setting. Recently, oscillations at gamma-band frequencies and above (>30 Hz) have been suggested to provide valuable localizing information of the EZ and track cortical activation associated with epileptogenic processes. Although a tight coupling between gamma-band activity and hemodynamic-based signals has been consistently demonstrated in non-pathological conditions, very little is known about whether such a relationship is maintained in epilepsy and the laminar etiology of these signals. Confirmation of this relationship may elucidate the underpinnings of perfusion-based signals in epilepsy and the potential value of localizing the EZ using hemodynamic correlates of pathological rhythms. Here, we use concurrent multi-depth electrophysiology and 2-dimensional optical imaging spectroscopy to examine the coupling between multi-band neural activity and cerebral blood volume (CBV) during recurrent acute focal neocortical seizures in the urethane-anesthetized rat. We show a powerful correlation between gamma-band power (25-90 Hz) and CBV across cortical laminae, in particular layer 5, and a close association between gamma measures and multi-unit activity (MUA). Our findings provide insights into the laminar electrophysiological basis of perfusion-based imaging signals in the epileptic state and may have implications for further research using non-invasive multi-modal techniques to localize epileptogenic tissue
Is ultrasonography-guided modified coaxial core biopsy of the breast a better technique?
Objective: To compare the diagnostic rate, patient comfort, and complications of ultrasonography-guided breast biopsy using a modified coaxial technique with ultrasonography-guided fine needle aspiration and traditional core biopsy. A secondary objective was to describe the use of the coaxial technique for the biopsy of breast lesions and our initial experience. Design: Retrospective study. Setting: A regional hospital in Hong Kong. Patients: Patients, who were referred for ultrasonography-guided fine needle aspiration or biopsy from 23 November 2007 to 19 March 2008, were divided into three groups. For breast lesions of 8 mm or smaller, fine needle aspirations were performed. For breast lesions larger than 8 mm, the patients were randomly divided into groups receiving traditional core biopsies and coaxial biopsies. The pathological reports were reviewed. Main outcome measures: Diagnostic rate, patient comfort assessed in terms of pain, and any procedural complications. Results: A total of 45 ultrasonography-guided fine needle aspirations or biopsies of breast lesions were performed. All core biopsies using the traditional core technique (n=15) and coaxial technique (n=16) were diagnostic. While for fine needle aspirations, three (21%) of 14 were not diagnostic and repeat biopsies were undertaken for the corresponding patients. Except for one breast lesion biopsied with the coaxial technique that revealed invasive ductal carcinoma, all others yielded benign lesions. The average pain score for coaxial biopsies was 2.2, while for traditional core biopsies and fine needle aspirations, average scores were 3.7 and 3.8, respectively (P=0.022). No procedure-related complication was documented with either of the three techniques. Conclusion: Modified coaxial core biopsy of the breast has an optimal diagnostic rate and hence avoids the need for repeat biopsies. It is associated with better patient comfort and no increase in the risk of complications.published_or_final_versio
Craniocerebral missile injuries in civilian Kashmir – India
Background The missile injuries of the cranium and brain in the modern era have shifted from soldiers to the civilians and from the battle grounds to the populated zones due to increase in the terrorist and military strikes. The management of the victims depends on the resuscitation at the site of injury and the distance and transportation to the tertiary care centre. This article presents the details of the missile injuries to the brain, the third-world problems and the management. Material and methods A retrospective analysis of 3794 craniocerebral missile injuries, managed by the Department of Neurosurgery at Sher-I-Kashmir Institute of Medical Sciences (SKIMS) Kashmir, India, over a period of more than 21 years from September 1988 to September 2009. Patients were triaged in emergency CT-room, resuscitated and operated. Statistical software programme SPSS 11.5 was used to derive the numerical significance. Results Revealed an overall mortality of 87.69% (3327 out of 3794). Most of the deaths 79.14% (2633 out of 3327) occurred within 30 minutes of the patient’s arrival to the hospital and only 694 patients lived beyond one hour of arrival. Conclusion Presently the quantum of outcome i.e, survival and good recovery in craniocerebral missile injuries appears a meager heap compared to the huge amount of death and disability. And the situation will continue to be so unless tertiary care hospitals are set up within and around the armed and conflict zones, war torn areas and battle fields, rather than risking transportation, time of resuscitation, intervention and the results.Key words: Craniocerebral, Kashmir, Missile Injuries, Outcome
Shortest paths in nearly conservative digraphs
We introduce the following notion: a digraph D = (V, A) with arc weights c: A → R is called nearly conservative if every negative cycle consists of two arcs. Computing shortest paths in nearly conservative digraphs is NP-hard, and even deciding whether a digraph is nearly conservative is coNP-complete. We show that the “All Pairs Shortest Path” problem is fixed parameter tractable with various parameters for nearly conservative digraphs. The results also apply for the special case of conservative mixed graphs
- …