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Fulltext Exploring intentions to discriminate against patients living with HIV/AIDS among future healthcare providers in Malaysia

Earnshaw VA, Jin H, Wickersham J, Kamarulzaman A, John J, Altice FL

Trop Med Int Health, 2014 Jun;19(6):672-679.
PMID: 24666546 DOI: 10.1111/tmi.12306

OBJECTIVES: Stigma towards people living with HIV/AIDS (PLWHA) is strong in Malaysia. Although stigma has been understudied, it may be a barrier to treating the approximately 81 000 Malaysian PLWHA. The current study explores correlates of intentions to discriminate against PLWHA among medical and dental students, the future healthcare providers of Malaysia.
METHODS: An online, cross-sectional survey of 1296 medical and dental students was conducted in 2012 at seven Malaysian universities; 1165 (89.9%) completed the survey and were analysed. Socio-demographic characteristics, stigma-related constructs and intentions to discriminate against PLWHA were measured. Linear mixed models were conducted, controlling for clustering by university.
RESULTS: The final multivariate model demonstrated that students who intended to discriminate more against PLWHA were female, less advanced in their training, and studying dentistry. They further endorsed more negative attitudes towards PLWHA, internalised greater HIV-related shame, reported more HIV-related fear and disagreed more strongly that PLWHA deserve good care. The final model accounted for 38% of the variance in discrimination intent, with 10% accounted for by socio-demographic characteristics and 28% accounted for by stigma-related constructs.
CONCLUSIONS: It is critical to reduce stigma among medical and dental students to eliminate intentions to discriminate and achieve equitable care for Malaysian PLWHA. Stigma-reduction interventions should be multipronged, addressing attitudes, internalised shame, fear and perceptions of deservingness of care.
KEYWORDS: HIV/AIDS; Malaisie; Malasia; Malaysia; VIH/SIDA; cuidados sanitarios profesionales; discriminación; discrimination; estigma; homosexuality; professional healthcare students; stigma; stigmatisation; substance abuse; étudiants en profession de soins de santé
Fulltext Endo-parasite fauna of rodents caught in five wet markets in Kuala Lumpur and its potential zoonotic implications

Paramasvaran S, Sani RA, Hassan L, Hanjeet K, Krishnasamy M, John J, et al.

Trop Biomed, 2009 Apr;26(1):67-72.
PMID: 19696729

Rodents were collected from five wet markets (Chow Kit, Dato Keramat, Setapak, Jinjang and Kepong) in Kuala Lumpur, Federal Territory between March to April 2006. Ninety seven rats were trapped using wire traps measuring 29 x 22 x 50 cm baited with fruits, coconuts, dried fish or sweet potatoes. A total of 17 different species of parasites were identified from three species of rats out of which 11 (65%) were identified to be zoonotic. The helminths identified from the urban rats were nematodes- Capillaria hepatica, Gongylonema neoplasticum, Heterakis spumosa, Heterakis sp., Masterphorus muris, Nippostrongylus brasiliensis, Physolaptera sp., Pterogodermatis sp., Rictularia tani and Syphacia muris; cestodes- Hymenolepis nana, Hymenolepis diminuta, Hymenolepis sabnema, Hymenolepis sp., Raillietina sp. and Taenia taeniaeformis, and acanthocephalan- Moniliformis moniliformis. The following parasites are of potential medical importance: C. hepatica, G. neoplasticum, R. tani, S. muris, H. diminuta, H. nana, Raillietina sp. and T. taeniaeformis.
Fulltext Ants (Hymenoptera: Formicidae) associated with pig carcasses in Malaysia

Heo CC, Mohamad AR, Rosli H, Nurul Ashikin A, Chen CD, John J, et al.

Trop Biomed, 2009 Apr;26(1):106-9.
PMID: 19696735

An observational study was conducted in an oil palm plantation in Tanjung Sepat, Selangor, Malaysia on August until September 2007 to note the decomposition process of pigs and their related faunal succession. We collected six species of ants (Formicidae) from 3 subfamilies: Formicinae (Oecophylla smaragdina and Anoplolepis gracilipes), Myrmicinae (Tetramorium sp. and Pheidologeton sp.) and Ponerinae (Odontoponera sp. and Diacamma sp.) that were associated with pig carcasses placed on the ground. Oecophylla smaragdina, Pheidologeton sp. and Tetramorium sp. were found on a partially burnt pig carcass whereas the other species were recovered from unburned pig carcass. These ants predated on fly eggs, larvae, pupae and adults. Ants could be found at all stages of decomposition starting from fresh until dry stage. Predatory ants can reduce fly population and thus may affect the rate of carcass decomposition but this was not seen in our study. Even though O. smaragdina was seen at all stages of decomposition of the burnt pig, this did not alter much the decomposition process by fly larvae.
Fulltext On the predation of fly, Chrysomya rufifacies (Macquart) by a spider, Oxyopes sp. Latreille (Oxyopidae)

Heo CC, Mohamad AM, John J, Baharudin O

Trop Biomed, 2008 Apr;25(1):93-5.
PMID: 18600210 MyJurnal

During a forensic entomological study conducted in a palm oil plantation in Tg.Sepat, Selangor in September 2007, a spider (Arachnida), Oxyopes sp. (Oxyopidae) was found to predate on a calliphorid fly (Chrysomya rufifacies). The female spider laid a silk thread, or "drag line", behind it as it moved. This spider bites its prey by using a pairs of chelicerae, and injecting venom into the fly. The fly was moving its wing trying to escape, however, it succumbed to the deadly bite.
Fulltext Insect succession on a decomposing piglet carcass placed in a man-made freshwater pond in Malaysia

Heo CC, Mohamad AM, John J, Baharudin O

Trop Biomed, 2008 Apr;25(1):23-9.
PMID: 18600201

This entomological study was conducted in a man-made freshwater pond in a palm oil plantation in Tanjung Sepat, Selangor from 23 July 2007 by using pig (Sus scrofa) as a carcass model. A 1.5 month old piglet (5 kg), which died of asphyxia after being accidentally crushed by its mother, was thrown into a pond. Observation was made for ten days; one visit per day and climatological data were recorded. On the first two days, the piglet carcass sunk to the bottom of the pond. The carcass floated to the surface on the third day but no fly activities were seen. The blow fly, Chrysomya megacephala and Chrysomya rufifacies started to oviposit on the fourth day. Other than adult flies, a spider (Arachnida) was also observed on the carcass. Bubbles accumulated at the mouthpart, and the abdomen was greenish black. A lot of blow fly eggs were seen on the body surface on the fifth day (floating decay), along with first and second instars C. megacephala crawling under the piglet's skin. On the sixth day, adult blow fly, C. megacephala,and C. rufifacies,and muscid flies, Ophyra spinigera and Musca domestica were observed on to the carcass. High numbers of first and second instars of flies were observed wandering around the body surface with C. megacephala larvae being the predominant species. Two prominent maggot masses occurred on seventh and eighth days. Bloated deterioration stage began on day eighth exposing rib bones, humerus bones and intestines. Carcass was partially sinking and the maggot masses were at the water level. On day ninth, the carcass was partially sinking and three maggot masses were observed on the exposed surface. There were very few adult flies, including a scarab beetle was sighted on the carcass at this stage. The carcass along with the maggots sunk on day tenth, leaving an oily layer on the water surface.
Fulltext Helminth infections in small mammals from Ulu Gombak Forest Reserve and the risk to human health

Paramasvaran S, Krishnasamy M, Lee HL, John J, Lokman H, Naseem BM, et al.

Trop Biomed, 2005 Dec;22(2):191-4.
PMID: 16883287 MyJurnal

A survey for small mammal parasites carried out in a secondary forest of Ulu Gombak, Selangor, Peninsula Malaysia yielded the following animals: Rattus bowersi (7), Rattus tiomanicus jalorensis (2), Maxomys rajah (12), Maxoyms whiteheadi (3), Leopoldamys sabanus(13), Sundamys muelleri(10), Lariscus insignis (1), Sundasciurus tenuis (1) and Tupaia glis (2). The following nematodes: Capillaria hepatica, Hepatojarakus malayae, Trichostrongylus sp. and Streptopharagus sp., the following cestodes: Hymenolepis sp., Raillietina sp. and Taenia taeniaformis; and trematode, Zonorchis sp. from Tupaia glis were recovered. No parasites were observed during blood examination. No endoparasite was seen in Maxomys whiteheadi, Lariscus insignis and Sundasciurus tenuis. The following parasites, Capillaria hepatica, Hymenolepis sp., Raillietina sp. and Taenia taeniaformis are considered of medical importance.
Fulltext Quantification of the dental morphology of orangutans

Nambiar P, John J, Al-Amery SM, Purmal K, Chai WL, Ngeow WC, et al.

ScientificWorldJournal, 2013;2013:213757.
PMID: 24348143 DOI: 10.1155/2013/213757

Orangutans are believed to have close biological affinities to humans. Teeth being the hardest tissue provide useful information on primate evolution. Furthermore, knowledge of the pulp chamber and root canal morphology is important for dental treatment. A female Bornean orangutan and a Sumatran male orangutan skull were available for this study. Both of their dentitions, comprising 50 teeth, were scanned employing the cone-beam computed tomography for both metrical and nonmetrical analyses. Measurements included tooth and crown length, root length, enamel covered crown height, root canal length (posterior teeth), length of pulpal space (anterior teeth), and root canal width. Nonmetrical parameters included number of canals per root, number of foramina in each root, and root canal morphology according to Vertucci's classification. It was found that the enamel covered crown height was the longest in the upper central incisors although the canine was the longest amongst the anterior teeth. Both the upper premolars were three-rooted while the lower second premolar of the Sumatran orangutan was two-rooted, with two foramina. The mandibular lateral incisors of the Bornean orangutan were longer than the central incisors, a feature similar to humans. In addition, secondary dentine deposition was noticed, a feature consistent with aged humans.
Prevalence and patterns of tooth agenesis among Malay children

Mani SA, Mohsin WS, John J

Southeast Asian J. Trop. Med. Public Health, 2014 Mar;45(2):490-8.
PMID: 24968691

Tooth agenesis in Malay children, hitherto unreported, was assessed retrospectively from orthopantomograms of 834 healthy children aged 12-16 years who attended the Dental Clinic of Universiti Sains Malaysia. All teeth, including third molars, were assessed for agenesis. On an average, 2.3 teeth were missing per child. Missing third molars were found in 25.7% of children with one or two third molars found to be missing in 18.3% of children. Three point two percent of children had missing teeth other than third molars. After third molars, the upper lateral incisors were found to be the most common missing tooth (1.7%), followed by upper and lower second premolars (1.5%). Eight missing upper canines were also seen (1%). Bilateral agenesis was more common than unilateral agenesis. There were no significant differences between males and females. There was a significant difference between missing teeth between the maxilla and the mandible and right and left side, with more missing teeth in the maxilla and on the right side. The odds of any 3rd molar missing were increased 3.3 times when there was any other missing tooth. In conclusion, the prevalence of tooth agenesis among the studied population was within the normal range, but less than some Asian countries. Unlike other Asian countries, the upper lateral incisor was the most common missing tooth. The prevalence of maxillary canine agenesis was higher than most previous reports. Missing teeth were associated with missing third molars, which is likely due to a genetic abnormality.
A review of Hib epidemiology in Asia

Lolekha S, Cooksley G, Chan V, Isahak I, Ismael S, John J, et al.

Southeast Asian J. Trop. Med. Public Health, 2000 Dec;31(4):650-7.
PMID: 11414406

Meningitis due to an invasive Haemophilus influenzae type b (Hib) infection, has been previously perceived to be relatively uncommon in Asia. However, the incidence of disease and its impact may have been underestimated. In addition to a lack of microbiological facilities in some hospitals, difficulties in culturing the organism and the widespread use of antibiotics may have hidden the true incidence of the disease in some countries. Furthermore, the reported disease burden probably underestimates the incidence of Hib pneumonia. The epidemiology of invasive Hib disease for various Asian nations is reviewed in this paper. Hospital-based studies show that Hib is a major cause of bacterial meningitis and/or pneumonia in the Philippines, India, Thailand, Malaysia, Indonesia and Vietnam. Singapore and Hong Kong have a low incidence of infection compared with Western and other Asian nations. This low incidence is not due to a higher level of natural protective antibodies, but may be related to an interaction between environmental and genetic factors. Therefore the widespread belief that Hib infection is unimportant in Asia does not refer to Asia as a whole and possibly to Chinese patients only, and failure to recognize this has serious implications. The inclusion of Hib vaccine in the routine infant immunization schedule in many industrialized nations has significantly reduced the incidence of invasive disease. Recent studies have shown Hib vaccination is also effective in preventing invasive disease in children in developing countries. While population-based data may be required to confirm the need for public-funded infant Hib immunization in Asia, its introduction in countries with a high incidence of Hib meningitis and/or pneumonia has the potential to significantly improve pediatric health and survival.
Fulltext Hepatitis A virus: declining seroprevalence in children and adolescents in Southeast Asia

Kunasol P, Cooksley G, Chan VF, Isahak I, John J, Loleka S, et al.

Southeast Asian J. Trop. Med. Public Health, 1998 Jun;29(2):255-62.
PMID: 9886108

The prevalence of hepatitis A virus (HAV) in a country largely reflects its standards of hygiene and socioeconomic conditions. Countries which undergo socioeconomic development show major change in HAV prevalence from high to low endemicity, and this is largely reflected in patterns of age-related seroprevalence. This paper presents age-related HAV seroprevalence patterns of SE Asian countries, and highlights how these patterns have changed over recent decades. Singapore, Thailand and Malaysia have experienced a decline in childhood and adolescent HAV seroprevalence, typical of countries which undergo socioeconomic development. By contrast, India has remained a country of high endemicity, with almost universal seroconversion in childhood. The Philippines and Vietnam show age-related seroprevalence patterns typical of high to moderate endemicity, while Indonesia shows significant regional variation in HAV seroprevalence. Populations within countries which exhibit major improvements in endemicity and age related HAV seroprevalence patterns are at risk of HAV epidemics, and a paradoxical increase in incidence tends to occur as seroconversion shifts from children to adults. The residents of these countries, a significant number of whom are at-risk, would benefit from a program of vaccination, as would non-infected individuals visiting high-risk areas.
Fulltext Oral health care in the elderly population in Malaysia--a review

John J, Mani SA, Azizah Y

Med J Malaysia, 2004 Aug;59(3):433-9.
PMID: 15727396

One of the undeniable facts about living is that everyday we are getting older. By 2050, it is projected that one out of every five Malaysians will be 60 or older. The economic challenge of this demographic change will affect development and the financial implications of sustaining well being of this group are formidable and complex. This population group has extensive oral disease, medical problems that complicate their oral care, and unique dental treatment challenges. The authors discuss the problem of oral healthcare among the aged, its impediments and propose some approaches for improvement to better serve the needs of this group of vulnerable members of our nation.
Pharmacy students in private institutions of higher education: motivating factors when studying pharmacy and influences on university choice

Loo JSE, Lim SW, Ng YK, Tiong JJL

Int J Pharm Pract, 2017 Dec;25(6):429-437.
PMID: 28211115 DOI: 10.1111/ijpp.12352

OBJECTIVES: To identify factors influencing the decisions of Malaysian first-year pharmacy undergraduate students in private higher education when choosing to pursue a degree in pharmacy as well as their choice of private university.
METHODS: This cross-sectional study employed a validated, self-administered questionnaire which was administered to 543 first-year pharmacy students from nine different private universities. Factor analysis was utilised to extract key factors from the responses. Descriptive and inferential statistics were used to analyse the data.
KEY FINDINGS: Eight factors motivating students' decision to study pharmacy emerged from the responses, accounting for 63.8% of the variance observed. Students were primarily motivated by intrinsic interests, with work conditions and profession attributes also exerting significant influence. In terms of choice of private university, nine factors were identified, accounting for 73.8% of the variance observed. The image of the school and university were most influential factors in this context, followed by university safety, programme attributes and financial factors.
CONCLUSIONS: First-year pharmacy students in the private higher education sector are motivated by intrinsic interest when choosing to study pharmacy over other courses, while their choice of private university is influenced primarily by the image of the school and university.
Searches for electroweak production of charginos, neutralinos, and sleptons decaying to leptons and W, Z, and Higgs bosons in pp collisions at 8 TeV

CMS Collaboration, Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Bergauer T, et al.

Eur Phys J C Part Fields, 2014 09 26;74(9):3036.
PMID: 25814912

Searches for the direct electroweak production of supersymmetric charginos, neutralinos, and sleptons in a variety of signatures with leptons and [Formula: see text], [Formula: see text], and Higgs bosons are presented. Results are based on a sample of proton-proton collision data collected at center-of-mass energy [Formula: see text] with the CMS detector in 2012, corresponding to an integrated luminosity of 19.5 [Formula: see text]. The observed event rates are in agreement with expectations from the standard model. These results probe charginos and neutralinos with masses up to 720 [Formula: see text], and sleptons up to 260 [Formula: see text], depending on the model details.
Search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks using a matrix element method

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Bergauer T, Dragicevic M, et al.

Eur Phys J C Part Fields, 2015 06 09;75(6):251.
PMID: 26097407

A search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks is presented. Events with hadronic jets and one or two oppositely charged leptons are selected from a data sample corresponding to an integrated luminosity of 19.5[Formula: see text] collected by the CMS experiment at the LHC in [Formula: see text] collisions at a centre-of-mass energy of 8[Formula: see text]. In order to separate the signal from the larger [Formula: see text] + jets background, this analysis uses a matrix element method that assigns a probability density value to each reconstructed event under signal or background hypotheses. The ratio between the two values is used in a maximum likelihood fit to extract the signal yield. The results are presented in terms of the measured signal strength modifier, [Formula: see text], relative to the standard model prediction for a Higgs boson mass of 125[Formula: see text]. The observed (expected) exclusion limit at a 95 % confidence level is [Formula: see text] (3.3), corresponding to a best fit value [Formula: see text].
Precise determination of the mass of the Higgs boson and tests of compatibility of its couplings with the standard model predictions using proton collisions at 7 and 8[Formula: see text]

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Bergauer T, Dragicevic M, et al.

Eur Phys J C Part Fields, 2015 05 14;75(5):212.
PMID: 25999783

Properties of the Higgs boson with mass near 125[Formula: see text] are measured in proton-proton collisions with the CMS experiment at the LHC. Comprehensive sets of production and decay measurements are combined. The decay channels include [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] pairs. The data samples were collected in 2011 and 2012 and correspond to integrated luminosities of up to 5.1[Formula: see text] at 7[Formula: see text] and up to 19.7[Formula: see text] at 8[Formula: see text]. From the high-resolution [Formula: see text] and [Formula: see text] channels, the mass of the Higgs boson is determined to be [Formula: see text]. For this mass value, the event yields obtained in the different analyses tagging specific decay channels and production mechanisms are consistent with those expected for the standard model Higgs boson. The combined best-fit signal relative to the standard model expectation is [Formula: see text] at the measured mass. The couplings of the Higgs boson are probed for deviations in magnitude from the standard model predictions in multiple ways, including searches for invisible and undetected decays. No significant deviations are found.
Measurement of the inclusive 3-jet production differential cross section in proton-proton collisions at 7 TeV and determination of the strong coupling constant in the TeV range

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Bergauer T, Dragicevic M, et al.

Eur Phys J C Part Fields, 2015 05 01;75(5):186.
PMID: 25983654

This paper presents a measurement of the inclusive 3-jet production differential cross section at a proton-proton centre-of-mass energy of 7 TeV using data corresponding to an integrated luminosity of 5[Formula: see text]collected with the CMS detector. The analysis is based on the three jets with the highest transverse momenta. The cross section is measured as a function of the invariant mass of the three jets in a range of 445-3270 GeV and in two bins of the maximum rapidity of the jets up to a value of 2. A comparison between the measurement and the prediction from perturbative QCD at next-to-leading order is performed. Within uncertainties, data and theory are in agreement. The sensitivity of the observable to the strong coupling constant [Formula: see text] is studied. A fit to all data points with 3-jet masses larger than 664 GeV gives a value of the strong coupling constant of [Formula: see text].
Search for dark matter, extra dimensions, and unparticles in monojet events in proton-proton collisions at [Formula: see text][Formula: see text]

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Bergauer T, Dragicevic M, et al.

Eur Phys J C Part Fields, 2015 05 29;75(5):235.
PMID: 26069461

Results are presented from a search for particle dark matter (DM), extra dimensions, and unparticles using events containing a jet and an imbalance in transverse momentum. The data were collected by the CMS detector in proton-proton collisions at the LHC and correspond to an integrated luminosity of 19.7[Formula: see text]at a centre-of-mass energy of 8[Formula: see text]. The number of observed events is found to be consistent with the standard model prediction. Limits are placed on the DM-nucleon scattering cross section as a function of the DM particle mass for spin-dependent and spin-independent interactions. Limits are also placed on the scale parameter [Formula: see text] in the Arkani-Hamed, Dimopoulos, and Dvali (ADD) model of large extra dimensions, and on the unparticle model parameter [Formula: see text]. The constraints on ADD models and unparticles are the most stringent limits in this channel and those on the DM-nucleon scattering cross section are an improvement over previous collider results.
Fulltext Search for direct pair production of supersymmetric top quarks decaying to all-hadronic final states in pp collisions at [Formula: see text]

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2016;76(8):460.
PMID: 28747851 DOI: 10.1140/epjc/s10052-016-4292-5

Results are reported from a search for the pair production of top squarks, the supersymmetric partners of top quarks, in final states with jets and missing transverse momentum. The data sample used in this search was collected by the CMS detector and corresponds to an integrated luminosity of 18.9[Formula: see text] of proton-proton collisions at a centre-of-mass energy of 8[Formula: see text] produced by the LHC. The search features novel background suppression and prediction methods, including a dedicated top quark pair reconstruction algorithm. The data are found to be in agreement with the predicted backgrounds. Exclusion limits are set in simplified supersymmetry models with the top squark decaying to jets and an undetected neutralino, either through a top quark or through a bottom quark and chargino. Models with the top squark decaying via a top quark are excluded for top squark masses up to 755[Formula: see text] in the case of neutralino masses below 200[Formula: see text]. For decays via a chargino, top squark masses up to 620[Formula: see text] are excluded, depending on the masses of the chargino and neutralino.
Fulltext Search for massive WH resonances decaying into the [Formula: see text] final state at [Formula: see text][Formula: see text]

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2016;76(5):237.
PMID: 28280427 DOI: 10.1140/epjc/s10052-016-4067-z

A search for a massive resonance [Formula: see text]decaying into a W and a Higgs boson in the [Formula: see text] ([Formula: see text], [Formula: see text]) final state is presented. Results are based on data corresponding to an integrated luminosity of 19.7[Formula: see text] of proton-proton collisions at [Formula: see text] [Formula: see text], collected using the CMS detector at the LHC. For a high-mass ([Formula: see text]1[Formula: see text]) resonance, the two bottom quarks coming from the Higgs boson decay are reconstructed as a single jet, which can be tagged by placing requirements on its substructure and flavour. Exclusion limits at 95 % confidence level are set on the production cross section of a narrow resonance decaying into WH, as a function of its mass. In the context of a little Higgs model, a lower limit on the [Formula: see text] mass of 1.4[Formula: see text] is set. In a heavy vector triplet model that mimics the properties of composite Higgs models, a lower limit on the [Formula: see text] mass of 1.5[Formula: see text] is set. In the context of this model, the results are combined with related searches to obtain a lower limit on the [Formula: see text] mass of 1.8[Formula: see text], the most restrictive to date for decays to a pair of standard model bosons.
Fulltext Measurement of [Formula: see text] production with additional jet activity, including [Formula: see text] quark jets, in the dilepton decay channel using pp collisions at [Formula: see text]

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2016;76(7):379.
PMID: 28280447 DOI: 10.1140/epjc/s10052-016-4105-x

Jet multiplicity distributions in top quark pair ([Formula: see text]) events are measured in pp collisions at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC using a data set corresponding to an integrated luminosity of 19.7[Formula: see text]. The measurement is performed in the dilepton decay channels ([Formula: see text], [Formula: see text], and [Formula: see text]). The absolute and normalized differential cross sections for [Formula: see text] production are measured as a function of the jet multiplicity in the event for different jet transverse momentum thresholds and the kinematic properties of the leading additional jets. The differential [Formula: see text] and [Formula: see text] cross sections are presented for the first time as a function of the kinematic properties of the leading additional [Formula: see text] jets. Furthermore, the fraction of events without additional jets above a threshold is measured as a function of the transverse momenta of the leading additional jets and the scalar sum of the transverse momenta of all additional jets. The data are compared and found to be consistent with predictions from several perturbative quantum chromodynamics event generators and a next-to-leading order calculation.

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