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匹配条件: “Ranil P. Nanayakkara” ,找到相关结果约200113条。
Re-discovery of Pouch bearing sheath tailed bat Saccolaimus saccolaimus Temminck (Chiroptera: Emballonuridae) from Sri Lanka after 75 years
Ranil P. Nanayakkara,Nilantha Vishvanath,T. G. Tharaka Kusuminda
Asian Journal of Conservation Biology , 2012,
Abstract: Saccolaimus saccolaimus Temminck, 1838, was first collected by the Museum of Natural History of Sri Lanka in the year 1919 and the first published record of this bat was in 1935 by W.W.A. Philips, though specimens were collected at various times for the collection of the Natural History Museum of Sri Lanka. However, after 1936 there were no records of the species, though, several surveys were conducted on the bat fauna of the island. The species had not been reported since, and was considered as Data Deficient according to latest literature. Here we report on its re-discovery.
The Range Extension of the Critically Endangered, Poecilotheria smithi in Sri Lanka, with Notes on its Sociality
Ranil P. Nanayakkara,Nilantha Vishvanath,T. G. Tharaka Kusuminda,G.A.S.M. Ganehiarachchi
Asian Journal of Conservation Biology , 2013,
Abstract: Poecilotheria smithi is a Critically Endangered Theraposid known only from the type locality Haragama in the Kandy District, Sri Lanka. It was thought to be distribution specific to Haragama. During a survey on the genus Poecilotheria, which was initiated in 2011 by the authors, P. smithi was recorded, the first confirmed observation of P. smithi outside of its type locality from the Matale district about 31.42 Km in aerial distance northwest of the type locality. Distribution of this species extended in Sri Lanka by this novel record. P. smithi displays the social behaviour of sharing same microhabitat with few individuals. As demonstrated for P. smithi, we suggest the large group size and social behaviour observed was in response to unavailability of suitable micro habitat for the mature individuals.
The puzzling symptom of paranoia: a response
Ranil Abeyasinghe
Sri Lanka Journal of Psychiatry , 2010,
Abstract: In a clinical setting where early diagnosis and intervention is necessary, the reliability of paranoia as a manifestation of psychosis in a series of cases has come under justifiable scrutiny by the authors. However, in so doing, due consideration must be given to factors such as the significance that could be attached to retrospective diagnoses, adolescent prodromal conditions, the diagnostic criteria for Asperger syndrome and personality and cultural factors, making the task of the psychiatrist rather complex.
Towards an evidence based alcohol policy
Ranil Abeyasinghe
Sri Lanka Journal of Psychiatry , 2011,
Abstract: Alcohol abuse is a major problem in Sri Lanka. Alcohol policies cannot be based on religious views, political expediency or tax revenue. Pitfalls in following policies followed in developed societies without regard to the local conditions abound. A sufficient body of evidence based knowledge exists today in the medical literature to help formulate a rational alcohol policy that suits Sri Lanka. The public and private sector agencies along with the medical profession should play an active role in formulating and enacting such a policy. The need to promote local research into alcohol related problems is also emphasized.
Terminal Resolutions of Brauer Pairs
Basil Nanayakkara
Mathematics , 2011,
Abstract: A Brauer pair is a pair (X, {\alpha}) where X is a quasi-projective variety over an algebraically closed field and {\alpha} is an element in the 2-torsion part of the Brauer group of the function field of X. A Brauer pair (Y, {\alpha}) is a terminal pair if the Brauer discrepancy of (Y, {\alpha}) is positive. We show that given a Brauer pair (X, {\alpha}), there is a terminal pair (Y, {\alpha}) with a birational morphism Y -> X. In short, any Brauer pair admits a terminal resolution.
Explicit energy expansion for general odd degree polynomial potentials
Asiri Nanayakkara,Thilagarajah Mathanaranjan
Physics , 2014, DOI: 10.1088/0031-8949/88/05/055004
Abstract: In this paper we derive an almost explicit analytic formula for asymptotic eigenenergy expansion of arbitrary odd degree polynomial potentials of the form $V(x)=(ix)^{2N+1}+\beta _{1}x^{2N}+\beta _{2}x^{2N-1}+\cdot \cdot \cdot \cdot \cdot +\beta _{2N}x$ where $\beta _{k}^{\prime }$s are real or complex for $1\leq k\leq 2N$. The formula can be used to find semiclassical analytic expressions for eigenenergies up to any order very efficiently. Each term of the expansion is given explicitly as a multinomial of the parameters $\beta _{1},\beta _{2}....$ and $\beta _{2N}$ of the potential. Unlike in the even degree polynomial case, the highest order term in the potential is pure imaginary and hence the system is non-Hermitian. Therefore all the integrations have been carried out along a contour enclosing two complex turning points which lies within a wedge in the complex plane. With the help of some examples we demonstrate the accuracy of the method for both real and complex eigenspectra.
Isospectral Hermitian counterpart of complex non Hermitian Hamiltonian $p^{2}-gx^{4}+a/x^{2}$
Asiri Nanayakkara,Thilagarajah Mathanaranjan
Physics , 2014, DOI: 10.1139/cjp-2012-0562
Abstract: In this paper we show that the non-Hermitian Hamiltonians $H=p^{2}-gx^{4}+a/x^2$ and the conventional Hermitian Hamiltonians $h=p^2+4gx^{4}+bx$ ($a,b\in \mathbb{R}$) are isospectral if $a=(b^2-4g\hbar^2)/16g$ and $a\geq -\hbar^2/4$. This new class includes the equivalent non-Hermitian - Hermitian Hamiltonian pair, $p^{2}-gx^{4}$ and $p^{2}+4gx^{4}-2\hbar \sqrt{g}x,$ found by Jones and Mateo six years ago as a special case. When $a=\left(b^{2}-4g\hbar ^{2}\right) /16g$ and $a<-\hbar^2/4,$ although $h$ and $H$ are still isospectral, $b$ is complex and $h$ is no longer the Hermitian counterpart of $H$.
Effects of complex parameters on classical trajectories of Hamiltonian systems
Asiri Nanayakkara,Thilagarajah Mathanaranjan
Physics , 2014, DOI: 10.1007/s12043-014-0750-5
Abstract: Anderson $\textit{et al}$ have shown that for complex energies, the classical trajectories of $\textit{real}$ quartic potentials are closed and periodic only on a discrete set of eigencurves. Moreover, recently it was revealed that, when time is complex $t$ $(t=t_{r}e^{i\theta _{\tau }}),$ certain real hermitian systems possess close periodic trajectories only for a discrete set of values of $\theta _{\tau }$. On the other hand it is generally true that even for real energies, classical trajectories of non $\mathcal{PT}$- symmetric Hamiltonians with complex parameters are mostly non-periodic and open. In this paper we show that for given real energy, the classical trajectories of $\textit{complex}$ quartic Hamiltonians $H=p^{2}+ax^{4}+bx^{k}$, (where $a$ is real, $b$ is complex and $k=1$ $or$ $2$) are closed and periodic only for a discrete set of parameter curves in the complex $b$-plane. It was further found that given complex parameter $b$, the classical trajectories are periodic for a discrete set of real energies (i.e. classical energy get discretized or quantized by imposing the condition that trajectories are periodic and closed). Moreover, we show that for real and positive energies (continuous), the classical trajectories of $\textit{complex}$ Hamiltonian $H=p^{2}+\mu x^{4}, (\mu=\mu _{r}e^{i\theta })$ are periodic when $\theta =4 tan^{-1}[(n/(2m+n))]$ for $\forall $ $ n$ and $m\in \mathbb{Z}$.
Sexual Dimorphism and Tooth Size Variation in the Permanent Dentition of the Uva Bintenna Veddas of Sri Lanka  [PDF]
Thushari Hewapathirana, Roshan Peiris, Deepthi Nanayakkara, Malkanthi Chandrasekara, Eugine Wikramanayake
Advances in Anthropology (AA) , 2014, DOI: 10.4236/aa.2014.41001

Forty-eight dental casts (37 males, 11 females) of Uva Bintenna Veddas were the population. Mesiodistal (MD) and buccolingual (BL) diameters were measured and analyzed for sexual dimorphism and size variation. In males, MD of maxillary canines and mandibular first molars were significantly greater at p < 0.01 and maxillary first molars and mandibular second molars at p < 0.05. Crown area was significantly greater at p < 0.01 for maxillary and mandibular first molars. Crown module was significantly greater at p < 0.01 for mandibular first molars and at p < 0.05 for maxillary first premolars, first molars and mandibular second molars. Maxillary canines, maxillary first molars and mandibular canines were the most sex ually dimorphic. First tooth of each tooth class I1, P1, and M1 showed least variability in both arches and in both sexes. In males, both MD and BL showed high variability in maxillary lateral incisors and mandibular second premolars.

Sri Lanka in global medical research: a scientific analysis of the Sri Lankan research output during 2000-2009
Priyanga Ranasinghe, Ranil Jayawardena, Prasad Katulanda
BMC Research Notes , 2012, DOI: 10.1186/1756-0500-5-121
Abstract: This study was based on Sri Lankan medical research publication data, retrieved from the SciVerse Scopus? from January 2000 to December 2009. The process of article selection was as follows: Affiliation - 'Sri Lanka' or 'Ceylon', Publication year - 'January 2000 to December 2009' and Subject area - 'Life and Health Sciences'. The articles identified were classified according to disease, medical speciality, institutions, major international collaborators, authors and journals.Sri Lanka's cumulative medical publications output between years 2000-2009 was 1,740 articles published in 160 different journals. The average annual publication growth rate was 9.1%. Majority of the articles were published in 'International' (n = 950, 54.6%) journals. Most articles were descriptive studies (n = 611, 35.1%), letters (n-345, 19.8%) and case reports (n = 311, 17.9%). The articles were authored by 148 different Sri Lankan authors from 146 different institutions. The three most prolific local institutions were Universities of; Colombo (n = 547), Kelaniya (n = 246) and Peradeniya (n = 222). Eighty four countries were found to have published collaborative papers with Sri Lankan authors during the last decade. UK was the largest collaborating partner (n = 263, 15.1%).Malaria (n = 75), Diabetes Mellitus (n = 55), Dengue (n = 53), Accidental injuries (n = 42) and Lymphatic filariasis (n = 40) were the major diseases studied. The 1,740 publications were cited 9,708 times, with an average citation of 5.6 per paper. The most cited paper had 203 citations, while there were 597 publications with no citations. The Sri Lankan authors' contribution to the global medical research output during the last decade was only 0.086%.The Sri Lankan medical research output during the last decade is only a small fraction of the global research output. There it is a necessity to setup an enabling environment for research, with a proper vision, support, funds and training. In addition, collaborations across t

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