Rodent Species Distribution and Hantavirus Seroprevalence in Residential and Forested areas of Sarawak, Malaysia.

Rodents belong to the order Rodentia, which consists of three families in Borneo (i.e., Muridae, Sciuridae and Hystricidae). These include rats, mice, squirrels, and porcupines. They are widespread throughout the world and considered pests that harm humans and livestock. Some rodent species are natural reservoirs of hantaviruses (Family: Bunyaviridae) that can cause zoonotic diseases in humans. Although hantavirus seropositive human sera were reported in Peninsular Malaysia in the early 1980s, information on their infection in rodent species in Malaysia is still lacking. The rodent populations in residential and forested areas in Sarawak were sampled. A total of 108 individuals from 15 species of rodents were collected in residential (n = 44) and forested ( n = 64) areas. The species diversity of rodents in forested areas was significantly higher (H = 2.2342) compared to rodents in residential areas (H = 0.64715) (p < 0.001 of Zar-t test based on the Shannon index). Rattus rattus and Sundamys muelleri were present at high frequencies in both localities. An enzyme-linked immunosorbent assay (ELISA) showed that hantavirus-targeting antibodies were absent from 53 tested serum samples. This is the first report of hantavirus seroprevalence surveillance in rodent populations in Sarawak, East Malaysia. The results suggested that hantavirus was not circulating in the studied rodent populations in Sarawak, or it was otherwise at a low prevalence that is below the detection threshold. It is important to remain vigilant because of the zoonotic potential of this virus and its severe disease outcome. Further studies, such as molecular detection of viral genetic materials, are needed to fully assess the risk of hantavirus infection in rodents and humans in this region of Malaysia.

An efficient reversible privacy-preserving data mining technology over data streams.

With the popularity of smart handheld devices and the emergence of cloud computing, users and companies can save various data, which may contain private data, to the cloud. Topics relating to data security have therefore received much attention. This study focuses on data stream environments and uses the concept of a sliding window to design a reversible privacy-preserving technology to process continuous data in real time, known as a continuous reversible privacy-preserving (CRP) algorithm. Data with CRP algorithm protection can be accurately recovered through a data recovery process. In addition, by using an embedded watermark, the integrity of the data can be verified. The results from the experiments show that, compared to existing algorithms, CRP is better at preserving knowledge and is more effective in terms of reducing information loss and privacy disclosure risk. In addition, it takes far less time for CRP to process continuous data than existing algorithms. As a result, CRP is confirmed as suitable for data stream environments and fulfills the requirements of being lightweight and energy-efficient for smart handheld devices.

A Novel Anti-classification Approach for Knowledge Protection.

Classification is the problem of identifying a set of categories where new data belong, on the basis of a set of training data whose category membership is known. Its application is wide-spread, such as the medical science domain. The issue of the classification knowledge protection has been paid attention increasingly in recent years because of the popularity of cloud environments. In the paper, we propose a Shaking Sorted-Sampling (triple-S) algorithm for protecting the classification knowledge of a dataset. The triple-S algorithm sorts the data of an original dataset according to the projection results of the principal components analysis so that the features of the adjacent data are similar. Then, we generate noise data with incorrect classes and add those data to the original dataset. In addition, we develop an effective positioning strategy, determining the added positions of noise data in the original dataset, to ensure the restoration of the original dataset after removing those noise data. The experimental results show that the disturbance effect of the triple-S algorithm on the CLC, MySVM, and LibSVM classifiers increases when the noise data ratio increases. In addition, compared with existing methods, the disturbance effect of the triple-S algorithm is more significant on MySVM and LibSVM when a certain amount of the noise data added to the original dataset is reached.

A HIPAA-compliant key management scheme with revocation of authorization.

Patient control over electronic protected health information (ePHI) is one of the major concerns in the Health Insurance and Accountability Act (HIPAA). In this paper, a new key management scheme is proposed to facilitate control by providing two functionalities. First, a patient can authorize more than one healthcare institute within a designated time period to access his or her ePHIs. Second, a patient can revoke authorization and add new authorized institutes at any time as necessary. In the design, it is not required to re-encrypt ePHIs for adding and revoking authorizations, and the implementation is time- and cost-efficient. Consent exception is also considered by the proposed scheme.

Elimination mechanisms of Br(2)+ and Br+ in photodissociation of 1,1- and 1,2-dibromoethylenes using velocity imaging technique.

Elimination pathways of the Br(2)(+) and Br(+) ionic fragments in photodissociation of 1,2- and 1,1-dibromoethylenes (C(2)H(2)Br(2)) at 233 nm are investigated using time-of-flight mass spectrometer equipped with velocity ion imaging. The Br(2)(+) fragments are verified not to stem from ionization of neutral Br(2), that is a dissociation channel of dibromoethylenes reported previously. Instead, they are produced from dissociative ionization of dibromoethylene isomers. That is, C(2)H(2)Br(2) is first ionized by absorbing two photons, followed by the dissociation scheme, C(2)H(2)Br(2)(+) + hv→Br(2)(+) + C(2)H(2). 1,2-C(2)H(2)Br(2) gives rise to a bright Br(2)(+) image with anisotropy parameter of -0.5 ± 0.1; the fragment may recoil at an angle of ∼66° with respect to the C=C bond axis. However, this channel is relatively slow in 1,1-C(2)H(2)Br(2) such that a weak Br(2)(+) image is acquired with anisotropy parameter equal to zero, indicative of an isotropic recoil fragment distribution. It is more complicated to understand the formation mechanisms of Br(+). Three routes are proposed for dissociation of 1,2-C(2)H(2)Br(2), including (a) ionization of Br that is eliminated from C(2)H(2)Br(2) by absorbing one photon, (b) dissociation from C(2)H(2)Br(2)(+) by absorbing two more photons, and (c) dissociation of Br(2)(+). Each pathway requires four photons to release one Br(+), in contrast to the Br(2)(+) formation that involves a three-photon process. As for 1,1-C(2)H(2)Br(2), the first two pathways are the same, but the third one is too weak to be detected.

A novel key management solution for reinforcing compliance with HIPAA privacy/security regulations.

Digitizing medical records facilitates the healthcare process. However, it can also cause serious security and privacy problems, which are the major concern in the Health Insurance Portability and Accountability Act (HIPAA). While various conventional encryption mechanisms can solve some aspects of these problems, they cannot address the illegal distribution of decrypted medical images, which violates the regulations defined in the HIPAA. To protect decrypted medical images from being illegally distributed by an authorized staff member, the model proposed in this paper provides a way to integrate several cryptographic mechanisms. In this model, the malicious staff member can be tracked by a watermarked clue. By combining several well-designed cryptographic mechanisms and developing a key management scheme to facilitate the interoperation among these mechanisms, the risk of illegal distribution can be reduced.

Photodissociation of cis-, trans-, and 1,1-dichloroethylene in the ultraviolet range: characterization of Cl((2)P(J)) elimination.

By using photofragment velocity imaging detection coupled with a (2 + 1) resonance-enhanced multiphoton ionization technique, the elimination channel of spin-orbit chlorine atoms in photodissociation of cis-, trans-, and 1,1-dichloroethylene at two photolysis wavelengths of 214.5 and 235 nm is investigated. Translational energy and angular distributions of Cl((2)P(J)) fragmentation are acquired. The Cl((2)P(J)) fragments are produced by two competing channels. The fast dissociation component with higher translational energy is characterized by a Gaussian distribution, resulting from a curve crossing of the initially excited (pi, pi*) state to nearby repulsive (pi, sigma*) and/or (n, sigma*). In contrast, the slow component with a lower translational energy is characterized by a Boltzmann distribution, which dissociates on the vibrationally hot ground state relaxed from the (pi, pi*) state via internal conversion. cis-C(2)H(2)Cl(2) is found to have a larger branching of Boltzmann component than the other two isomers. The fraction of available energy partitioning into translation increases along the trend of cis- < trans- < 1,1-C(2)H(2)Cl(2). This trend may be fitted by a rigid radical model and interpreted by means of a torque generated during the C-Cl bond cleavage. The anisotropy parameters are determined, and the transition dipole moments are expected to be essentially along the C horizontal lineC bond axis. The results are also predicted theoretically. The relative quantum yields of Cl((2)P(J)) have a similar value for the three isomers at the two photolysis wavelengths.

Photodissociation of (ICN)(2) van der Waals dimer using velocity imaging technique.

Photodissociation of (ICN)(2) dimer from 265 to 270 nm are studied using time-of-flight mass spectrometry combined with velocity imaging technique. Both I(+) and I(2) (+) ions are found in the mass spectra. The I(2) (+) ions result from (1+1) resonant ionization of the neutral I(2) fragment that is produced in the photodissociation of dimer, but not from dissociative ionization of (ICN)(2); i.e., (ICN)(2) (+)+hnu-->I(2) (+)+2CN. The dissociation channels of I(2) (+) leading to I(+) are all found with parallel character. The total kinetic energy distributions and anisotropy parameters of the I(+) channels produced by (ICN)(2) are almost the same as those from a neutral I(2) sample, thereby confirming that the I(2) fragments are obtained in cold state. With the aid of ab initio calculations, a plausible dissociation mechanism is proposed.

Photodissociation dynamics of propionyl chloride in the ultraviolet region.

Velocity imaging technique combined with (2+1) resonance-enhanced multiphoton ionization (REMPI) is used to detect primary photodissociation of propionyl chloride. In one-color experiments at 235 nm, the Cl and Cl(*) fragments are produced rapidly, leading to a fraction of translational energy release of 0.37 and 0.35, anisotropy parameters of 1.1 and 0.8, and quantum yield of 0.67 and 0.33, respectively, when initial excitation of the (1)(n, pi(*))(CO) band is coupled to the (1)(n(Cl), sigma(C-Cl)(*)) repulsive configuration. The resulting propionyl radical with sufficient internal energy may undergo secondary dissociation to yield CO that is characteristic of an isotropic distribution. The REMPI spectra of the CO (0,0) and (1,1) bands are measured, giving rise to a Boltzmann rotational temperature of 1200 and 770 K, respectively, and a Boltzmann vibrational temperature of 2800 K. A minor channel of HCl elimination is not detected, probably because of predissociation in two-photon absorption at 235 nm. In two-color experiments comprising an additional 248 nm photolyzing laser, Cl and Cl(*) are produced with a fraction of translational energy release of 0.43 and 0.40 and anisotropy parameters of 1.0 and 0.6, respectively. The secondary production of CO is not observed although the internal energy partitioned in the propionyl radical is in the proximity of the dissociation barrier. In either experimental scheme, a small component appearing in the center of the Cl and Cl(*) images is proposed to stem from ground state dissociation via internal conversion.

Nonadiabatic transition in the A-band photodissociation of ethyl iodide from 294 to 308 nm by using velocity imaging detection.

Photodissociation dynamics of ethyl iodide in the A-band is investigated at wavelengths between 294 and 308 nm using resonance-enhanced multiphoton ionization technique combined with velocity imaging detection. The I/I* branching, translational energy disposals, anisotropy parameters, and curve crossing probabilities of the dissociation channels are determined. The I(5p(2)P(3/2))-product channel is found to have hotter internal states of C(2)H(5), and the I*(5p(2)P(1/2)) channel is accompanied by colder C(2)H(5). Anisotropy parameters (beta) for the I* channel remain at 2.0, indicating that the I* production should originate from the (3)Q(0) state. The beta values are from 1.6 to 1.9 in the I-product channel, which comprises two components of direct excitation of (3)Q(1) and nonadiabatic transition between the (3)Q(0) and (1)Q(1) states. The curve crossing probability rises rapidly around the conical intersection but remains almost constant after passing through the curve crossing. The (1)Q(1) and (3)Q(0) states in the exit region are thus expected to cross almost parallel along the dissociation coordinate. As compared to the case of CH(3)I, the nonadiabatic transition probabilities are slightly enhanced by an ethyl-substituted group.

Photodissociation of dibromobenzenes at 266 nm by the velocity imaging technique.

A velocity imaging technique combined with (2+1) resonance-enhanced multiphoton ionization (REMPI) is used to detect the primary Br((2)P(3/2)) fragment in the photodissociation of o-, m-, and p-dibromobenzene at 266 nm. The obtained translational energy distributions suggest that the Br fragments are produced via two dissociation channels. For o- and m-dibromobenzene, the slow channel that yields an anisotropy parameter close to zero is proposed to stem from excitation of the lowest excited singlet (pi,pi*) state followed by predissociation along a repulsive triplet (n,sigma*) state localized on the C-Br bond. The fast channel that gives rise to an anisotropy parameter of 0.53-0.73 is attributed to a bound triplet state with smaller dissociation barrier. For p-dibromobenzene, the dissociation rates are reversed, because the barrier for the bound triplet state becomes higher than the singlet-triplet crossing energy. The fractions of translational energy release are determined to be 6-8 and 29-40 % for the slow and fast channels, respectively; the quantum yields are 0.2 and 0.8, and are insensitive to the position of the substituent. The Br fragmentation from bromobenzene and bromofluorobenzenes at the same photolyzing wavelength is also compared to understand the effect of the number of halogen atoms on the phenyl ring.

(1+1) Resonance-enhanced multiphoton ionization and photodissociation study of CS2 via the 1B2 state.

(1+1) Resonance-enhanced multiphoton ionization (REMPI) spectra of CS(2) and molecular dissociation dynamics are investigated using a time-of-flight mass spectrometer equipped with velocity imaging detection. The REMPI spectra via a linear-bent 1Sigma(g)+-->(1)B(2)(1Sigma(u)+) transition are acquired in the wavelength range of 208-217 nm. Each ro-vibrational band profile of the (1)B(2)(1Sigma(u)+) state is deconvoluted to yield the corresponding predissociative lifetime from 0.3 to 3 ps. Upon excitation at 210.25 and 212.54 nm, the resulting images of S(+) and CS(+) fragments are analyzed to give individual translational energy distributions, which are resolved into two components corresponding to the CS+S((3)P) and CS+S((1)D) channels. The product branching ratios of S((3)P)/S((1)D) are evaluated to be 5.7+/-1.0 and 9.6+/-2.5 at 210.25 and 212.54 nm, respectively. Despite the difficulty avoiding the effect of multiphoton absorption, the molecular dissociation channel is verified to prevail over the dissociative ionization channel of CS(2). The anisotropy parameters for the triplet and singlet channels are determined to be approximately 0.8 and 1.1-1.3, respectively, suggesting that the predissociative state should have a bent configuration with a short lifetime.

Photodissociation dynamics of bromofluorobenzenes using velocity imaging technique.

Velocity imaging technique combined with (2 + 1) resonance-enhanced multiphoton ionization (REMPI) has been used to detect the Br fragment in photodissociation of o-, m-, and p-bromofluorobenzene at 266 nm. The branching ratio of ground state Br(2P3/2) is found to be larger than 96%. Its translational energy distributions suggest that the Br fragments are generated via two dissociation channels for all the molecules. The fast route, which is missing in p-bromofluorobenzene detected previously by femtosecond laser spectroscopy, giving rise to an anisotropy parameter of 0.50-0.65, is attributed to a direct dissociation from a repulsive triplet T1(A' ') or T1(B1) state. The slow one with anisotropy parameter close to zero is proposed to stem from excitation of the lowest excited singlet (pi,pi*)state followed by predissociation along a repulsive triplet (pi,sigma*) state localized on the C-Br bond. For the minor product of spin-orbit excited state Br(2P1/2), the dissociating features are similar to those found in Br(2P3/2). Our kinetic and anisotropic features of decomposition obtained in m- and p-bromofluorobenzene are opposed to those by photofragment translational spectroscopy. Discrepancy between different methods is discussed in detail.

Productions of I, I*, and C2H5 in the A-band photodissociation of ethyl iodide in the wavelength range from 245 to 283 nm by using ion-imaging detection.

Photodissociation dynamics of ethyl iodide in the A band has been investigated at several wavelengths between 245 and 283 nm using resonance-enhanced multiphoton ionization technique combined with velocity map ion-imaging detection. The ion images of I, I(*), and C(2)H(5) fragments are analyzed to yield corresponding speed and angular distributions. Two photodissociation channels are found: I(5p (2)P(3/2))+C(2)H(5) (hotter internal states) and I(*)(5p (2)P(1/2))+C(2)H(5) (colder). In addition, a competitive ionization dissociation channel, C(2)H(5)I(+)+h nu-->C(2)H(5)+I(+), appears at the wavelengths <266 nm. The I/I(*) branching of the dissociation channels may be obtained directly from the C(2)H(5) (+) images, yielding the quantum yield of I(*) about 0.63-0.76, comparable to the case of CH(3)I. Anisotropy parameters (beta) determined for the I(*) channel remain at 1.9+/-0.1 over the wavelength range studied, indicating that the I(*) production should originate from the (3)Q(0) state. In contrast, the beta(I) values become smaller above 266 nm, comprising two components, direct excitation of (3)Q(1) and nonadiabatic transition between the (3)Q(0) and (1)Q(1) states. The curve crossing probabilities are determined to be 0.24-0.36, increasing with the wavelength. A heavier branched ethyl group does not significantly enhance the I(5p (2)P(3/2)) production from the nonadiabatic contribution, as compared to the case of CH(3)I.

Br2 molecular elimination in 248 nm photolysis of CHBr2Cl by using cavity ring-down absorption spectroscopy.

Elimination of molecular bromine is probed in the B (3)Pi(ou) (+)<--X (1)Sigma(g) (+) transition following photodissociation of CHBr(2)Cl at 248 nm by using cavity ring-down absorption spectroscopy. The quantum yield for the Br(2) elimination reaction is determined to be 0.05+/-0.03. The nascent vibrational population ratio of Br(2)(v=1)Br(2)(v=0) is obtained to be 0.5+/-0.2. A supersonic beam of CHBr(2)Cl is similarly photofragmented and the resulting Br atoms are monitored with a velocity map ion-imaging detection, yielding spatial anisotropy parameters of 1.5 and 1.1 with photolyzing wavelengths of 234 and 267 nm, respectively. The results justify that the excited state promoted by 248 nm should have an A(") symmetry. Nevertheless, when CHBr(2)Cl is prepared in a supersonic molecular beam under a cold temperature, photofragmentation gives no Br(2) detectable in a time-of-flight mass spectrometer. A plausible pathway via internal conversion is proposed with the aid of ab initio potential energy calculations. Temperature dependence measurements lend support to the proposed pathway. The production rates of Br(2) between CHBr(2)Cl and CH(2)Br(2) are also compared to examine the chlorine-substituted effect.

248 nm photolysis of CH2Br2 by using cavity ring-down absorption spectroscopy: Br2 molecular elimination at room temperature.

Following photodissociation of CH2Br2 at 248 nm, Br2 molecular elimination is detected by using a tunable laser beam, as crossed perpendicular to the photolyzing laser beam in a ring-down cell, probing the Br2 fragment in the B 3Piou+ -X 1Sigmag+ transition. The nascent vibrational population is obtained, yielding a population ratio of Br2(v = 1)Br2(v = 0) to be 0.7 +/- 0.2. The quantum yield for the Br2 elimination reaction is determined to be 0.2 +/- 0.1. Nevertheless, when CH2Br2 is prepared in a supersonic molecular beam under cold temperature, photofragmentation gives no Br2 detectable in a time-of-flight mass spectrometer. With the aid of ab initio potential energy calculations, a plausible pathway is proposed. Upon excitation to the 1B1 or 3B1 state, C-Br bond elongation may change the molecular symmetry of Cs and enhance the resultant 1 1,3A'-X 1A' (or 1 1,3B1-X 1A1 as C2v is used) coupling to facilitate the process of internal conversion, followed by asynchronous concerted photodissociation. Temperature dependence measurements lend support to the proposed pathway.